WorldWideScience

Sample records for tropical regions based

  1. Analyzing cloud base at local and regional scales to understand tropical montane cloud forest vulnerability to climate change

    Science.gov (United States)

    Ashley E. Van Beusekom; Grizelle Gonzalez; Martha A. Scholl

    2017-01-01

    The degree to which cloud immersion provides water in addition to rainfall, suppresses transpiration, and sustains tropical montane cloud forests (TMCFs) during rainless periods is not well understood. Climate and land use changes represent a threat to these forests if cloud base altitude rises as a result of regional warming or deforestation. To establish a baseline...

  2. Future Urban Climate Projection in A Tropical Megacity Based on Global and Regional Scenarios

    Science.gov (United States)

    Darmanto, N. S.; Varquez, A. C. G.; Kanda, M.

    2017-12-01

    Cities in Asian developing countries experience rapid transformation in urban morphology and energy consumption, which correspondingly affects urban climate. Weather Research and Forecasting (WRF) Model coupled with improved single-layer urban canopy model incorporating realistic distribution of urban parameters and anthropogenic heat emission (AHE) in the tropic Jakarta Greater Area was conducted. Simulation was conducted during the dry months from 2006 to 2015 and agreed well with point and satellite observation. The same technology coupled with pseudo global warming (PGW) method based on representative concentration pathways (RCP) scenario 2.6 and 8.5 was conducted to produce futuristic climate condition in 2050. Projected urban morphology and AHE in 2050s were constructed using regional urban growing model with shared socioeconomic pathways (SSP) among its inputs. Compact future urban configuration, based on SSP1, was coupled to RCP2.6. Unrestrained future urban configuration, based on SSP3, was coupled to RCP8.5. Results show that background warming from RCP 2.6 and 8.5 will increase background temperature by 0.55°C and 1.2°C throughout the region, respectively. Future projection of urban sprawl results to an additional 0.3°C and 0.5°C increase on average, with maximum increase of 1.1°C and 1.3°C due to urban effect for RCP2.6/compact and RCP8.5/unrestrained, respectively. Higher moisture content in urban area is indicated in the future due to higher evaporation. Change in urban roughness is likely affect slower wind velocity in urban area and sea breeze front inland penetration the future compare with current condition. Acknowledgement: This research was supported by the Environment Research and Technology Development Fund (S-14) of the Ministry of the Environment, Japan.

  3. Disdrometer-based C-Band Radar Quantitative Precipitation Estimation (QPE) in a highly complex terrain region in tropical Colombia.

    Science.gov (United States)

    Sepúlveda, J.; Hoyos Ortiz, C. D.

    2017-12-01

    An adequate quantification of precipitation over land is critical for many societal applications including agriculture, hydroelectricity generation, water supply, and risk management associated with extreme events. The use of rain gauges, a traditional method for precipitation estimation, and an excellent one, to estimate the volume of liquid water during a particular precipitation event, does not allow to fully capture the highly spatial variability of the phenomena which is a requirement for almost all practical applications. On the other hand, the weather radar, an active remote sensing sensor, provides a proxy for rainfall with fine spatial resolution and adequate temporary sampling, however, it does not measure surface precipitation. In order to fully exploit the capabilities of the weather radar, it is necessary to develop quantitative precipitation estimation (QPE) techniques combining radar information with in-situ measurements. Different QPE methodologies are explored and adapted to local observations in a highly complex terrain region in tropical Colombia using a C-Band radar and a relatively dense network of rain gauges and disdrometers. One important result is that the expressions reported in the literature for extratropical locations are not representative of the conditions found in the tropical region studied. In addition to reproducing the state-of-the-art techniques, a new multi-stage methodology based on radar-derived variables and disdrometer data is proposed in order to achieve the best QPE possible. The main motivation for this new methodology is based on the fact that most traditional QPE methods do not directly take into account the different uncertainty sources involved in the process. The main advantage of the multi-stage model compared to traditional models is that it allows assessing and quantifying the uncertainty in the surface rain rate estimation. The sub-hourly rainfall estimations using the multi-stage methodology are realistic

  4. Analyzing cloud base at local and regional scales to understand tropical montane cloud forest vulnerability to climate change

    Science.gov (United States)

    Van Beusekom, Ashley E.; González, Grizelle; Scholl, Martha A.

    2017-01-01

    The degree to which cloud immersion provides water in addition to rainfall, suppresses transpiration, and sustains tropical montane cloud forests (TMCFs) during rainless periods is not well understood. Climate and land use changes represent a threat to these forests if cloud base altitude rises as a result of regional warming or deforestation. To establish a baseline for quantifying future changes in cloud base, we installed a ceilometer at 100 m altitude in the forest upwind of the TMCF that occupies an altitude range from ∼ 600 m to the peaks at 1100 m in the Luquillo Mountains of eastern Puerto Rico. Airport Automated Surface Observing System (ASOS) ceilometer data, radiosonde data, and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite data were obtained to investigate seasonal cloud base dynamics, altitude of the trade-wind inversion (TWI), and typical cloud thickness for the surrounding Caribbean region. Cloud base is rarely quantified near mountains, so these results represent a first look at seasonal and diurnal cloud base dynamics for the TMCF. From May 2013 to August 2016, cloud base was lowest during the midsummer dry season, and cloud bases were lower than the mountaintops as often in the winter dry season as in the wet seasons. The lowest cloud bases most frequently occurred at higher elevation than 600 m, from 740 to 964 m. The Luquillo forest low cloud base altitudes were higher than six other sites in the Caribbean by ∼ 200–600 m, highlighting the importance of site selection to measure topographic influence on cloud height. Proximity to the oceanic cloud system where shallow cumulus clouds are seasonally invariant in altitude and cover, along with local trade-wind orographic lifting and cloud formation, may explain the dry season low clouds. The results indicate that climate change threats to low-elevation TMCFs are not limited to the dry season; changes in synoptic-scale weather patterns

  5. Predictive Models of Primary Tropical Forest Structure from Geomorphometric Variables Based on SRTM in the Tapajós Region, Brazilian Amazon.

    Science.gov (United States)

    Bispo, Polyanna da Conceição; Dos Santos, João Roberto; Valeriano, Márcio de Morisson; Graça, Paulo Maurício Lima de Alencastro; Balzter, Heiko; França, Helena; Bispo, Pitágoras da Conceição

    2016-01-01

    Surveying primary tropical forest over large regions is challenging. Indirect methods of relating terrain information or other external spatial datasets to forest biophysical parameters can provide forest structural maps at large scales but the inherent uncertainties need to be evaluated fully. The goal of the present study was to evaluate relief characteristics, measured through geomorphometric variables, as predictors of forest structural characteristics such as average tree basal area (BA) and height (H) and average percentage canopy openness (CO). Our hypothesis is that geomorphometric variables are good predictors of the structure of primary tropical forest, even in areas, with low altitude variation. The study was performed at the Tapajós National Forest, located in the Western State of Pará, Brazil. Forty-three plots were sampled. Predictive models for BA, H and CO were parameterized based on geomorphometric variables using multiple linear regression. Validation of the models with nine independent sample plots revealed a Root Mean Square Error (RMSE) of 3.73 m2/ha (20%) for BA, 1.70 m (12%) for H, and 1.78% (21%) for CO. The coefficient of determination between observed and predicted values were r2 = 0.32 for CO, r2 = 0.26 for H and r2 = 0.52 for BA. The models obtained were able to adequately estimate BA and CO. In summary, it can be concluded that relief variables are good predictors of vegetation structure and enable the creation of forest structure maps in primary tropical rainforest with an acceptable uncertainty.

  6. Optimum Tilt Angle at Tropical Region

    Directory of Open Access Journals (Sweden)

    S Soulayman

    2015-02-01

    Full Text Available : One of the important parameters that affect the performance of a solar collector is its tilt angle with the horizon. This is because of the variation of tilt angle changes the amount of solar radiation reaching the collector surface. Meanwhile, is the rule of thumb, which says that solar collector Equator facing position is the best, is valid for tropical region? Thus, it is required to determine the optimum tilt as for Equator facing and for Pole oriented collectors. In addition, the question that may arise: how many times is reasonable for adjusting collector tilt angle for a definite value of surface azimuth angle? A mathematical model was used for estimating the solar radiation on a tilted surface, and to determine the optimum tilt angle and orientation (surface azimuth angle for the solar collector at any latitude. This model was applied for determining optimum tilt angle and orientation in the tropical zones, on a daily basis, as well as for a specific period. The optimum angle was computed by searching for the values for which the radiation on the collector surface is a maximum for a particular day or a specific period. The results reveal that changing the tilt angle 12 times in a year (i.e. using the monthly optimum tilt angle maintains approximately the total amount of solar radiation near the maximum value that is found by changing the tilt angle daily to its optimum value. This achieves a yearly gain in solar radiation of 11% to 18% more than the case of a solar collector fixed on a horizontal surface.

  7. Field based investigation on phytoremediation potentials of Lemna minor and Azolla filiculoides in tropical, semiarid regions: Case of Ethiopia.

    Science.gov (United States)

    Amare, Elfu; Kebede, Fassil; Berihu, Tesfay; Mulat, Worku

    2017-10-16

    This study investigated the concurrent accumulation of eight heavy metals by two floating aquatic macrophytes (Lemna minor and Azolla filiculoides) cultivated in ambient media and blended wastewaters in the semiarid regions of Ethiopia. Both species accumulated heavy metals in varying degrees with a significant concentration gradient within the immediate water media. Highest bioconcentration factor was determined for Mn and Fe in both plants. Results revealed that L. minor was high phytoaccumulator for Fe, Mn, Zn and Co but moderate for Cd, Cu, Ni and Cr. On the other hand, A. filiculoides was a high accumulator for Fe, Mn, Zn and Cu, but its potency was moderate for Co, Cr and Ni, but lower for Cd. Both species exhibited significant difference in accumulating Co, Zn and Mn (p < 0.05). In general, the bioconcentration factors for both plants were comparable within the same treatment. In this study, stronger associations between the heavy metal concentrations in the plant tissues and in the grown water media were observed for A. filiculoides.

  8. Extracted atmospheric impairments on earth-sky signal quality in tropical regions at Ku-band

    Science.gov (United States)

    Al-Saegh, Ali Mohammed; Sali, Aduwati; Mandeep, J. S.; Ismail, Alyani

    2013-11-01

    Atmospheric condition variations were shown to have a major effect on the earth sky signal quality at Ku band. Moreover, such variations increased in the tropical regions as compared to temperate areas due to their different weather parameters. With the increase of recent satellite communication technology applications throughout the tropical countries and lack of information regarding the atmospheric impairments analysis, simulation and mitigation techniques, there is an ever increasing need for extracting a unique and accurate performance of the signal quality effects during highly natural tropical weather impairments. This paper presents a new method developed for proper analysis with distinctive and highly realistic performance evaluation for signal quality during the atmospheric conditions variations in 14 tropical areas from the four continents analyzed based on actual measured parameters. The method implementation includes signal attenuation, carrier to noise ratio, symbol energy to noise ratio, and symbol error rate at different areas and different modulation schemes. Furthermore, for improvement in analysis in terms of covering more remarkable regions in tropics, the paper provides new measurements data with analysis for certain region in tropics used as a test bed and to add measurement data of such area to the world's data base for future researchers. The results show a significant investigation and performance observation in terms of weather impairments in tropical regions in general and each region in that area in particular regarding the signal attenuation and error rates accompanied for several transmission schemes.

  9. 7 CFR 1437.505 - Application for payment for the tropical region.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Application for payment for the tropical region. 1437... DISASTER ASSISTANCE PROGRAM Determining Coverage in the Tropical Region § 1437.505 Application for payment for the tropical region. (a) For producers of covered tropical crops in Guam, Virgin Islands, American...

  10. Assessing diversity and phytoremediation potential of seagrass in tropical region

    Science.gov (United States)

    Seagrass ecosystem is one of the most important resources in the coastal areas. Seagrasses support and provide habitats for many coastal organisms in tropical region. Seagrasses are specialized marine flowering plants that have adapted to the nearshore environment with heterogeneous landscape struct...

  11. Regional impacts of ocean color on tropical Pacific variability

    Science.gov (United States)

    Anderson, W.; Gnanadesikan, A.; Wittenberg, A.

    2009-08-01

    The role of the penetration length scale of shortwave radiation into the surface ocean and its impact on tropical Pacific variability is investigated with a fully coupled ocean, atmosphere, land and ice model. Previous work has shown that removal of all ocean color results in a system that tends strongly towards an El Niño state. Results from a suite of surface chlorophyll perturbation experiments show that the mean state and variability of the tropical Pacific is highly sensitive to the concentration and distribution of ocean chlorophyll. Setting the near-oligotrophic regions to contain optically pure water warms the mean state and suppresses variability in the western tropical Pacific. Doing the same above the shadow zones of the tropical Pacific also warms the mean state but enhances the variability. It is shown that increasing penetration can both deepen the pycnocline (which tends to damp El Niño) while shifting the mean circulation so that the wind response to temperature changes is altered. Depending on what region is involved this change in the wind stress can either strengthen or weaken ENSO variability.

  12. Regional impacts of ocean color on tropical Pacific variability

    Directory of Open Access Journals (Sweden)

    W. Anderson

    2009-08-01

    Full Text Available The role of the penetration length scale of shortwave radiation into the surface ocean and its impact on tropical Pacific variability is investigated with a fully coupled ocean, atmosphere, land and ice model. Previous work has shown that removal of all ocean color results in a system that tends strongly towards an El Niño state. Results from a suite of surface chlorophyll perturbation experiments show that the mean state and variability of the tropical Pacific is highly sensitive to the concentration and distribution of ocean chlorophyll. Setting the near-oligotrophic regions to contain optically pure water warms the mean state and suppresses variability in the western tropical Pacific. Doing the same above the shadow zones of the tropical Pacific also warms the mean state but enhances the variability. It is shown that increasing penetration can both deepen the pycnocline (which tends to damp El Niño while shifting the mean circulation so that the wind response to temperature changes is altered. Depending on what region is involved this change in the wind stress can either strengthen or weaken ENSO variability.

  13. Effect of Nock-Ten Tropical Cyclone on Atmospheric Condition and Distribution of Rainfall in Gorontalo, Ternate, and Sorong Regions

    Science.gov (United States)

    Lumbangaol, A.; Serhalawan, Y. R.; Endarwin

    2017-12-01

    Nock-Ten Tropical Cyclone is an atmospheric phenomenon that has claimed many lives in the Philippines. This super-typhoon cyclone grows in the Western Pacific Ocean, North of Papua. With the area directly contiguous to the trajectory of Nock-Ten Tropical Cyclone growth, it is necessary to study about the growth activity of this tropical cyclones in Indonesia, especially in 3 different areas, namely Gorontalo, Ternate, and Sorong. This study was able to determine the impact of Nock-Ten Tropical Cyclone on atmospheric dynamics and rainfall growth distribution based on the stages of tropical cyclone development. The data used in this study include Himawari-8 IR channel satellite data to see the development stage and movement track of Tropical Cyclone Nock-Ten, rainfall data from TRMM 3B42RT satellite product to know the rain distribution in Gorontalo, Ternate, and Sorong, and reanalysis data from ECMWF such as wind direction and speed, vertical velocity, and relative vorticity to determine atmospheric conditions at the time of development of the Nock-Ten Tropical Cyclone. The results of data analysis processed using GrADS application showed the development stage of Nock-Ten Tropical Cyclone has effect of changes in atmospheric dynamics condition and wind direction pattern. In addition, tropical cyclones also contribute to very light to moderate scale intensity during the cycle period of tropical cyclone development in all three regions.

  14. Human amplification of drought-driven fire in tropical regions

    Science.gov (United States)

    Tosca, Michael

    2015-04-01

    The change in globally-measured radiative forcing from the pre-industrial to the present due to interactions between aerosol particles and cloud cover has the largest uncertainty of all anthropogenic factors. Uncertainties are largest in the tropics, where total cloud amount and incoming solar radiation are highest, and where 50% of all aerosol emissions originate from anthropogenic fire. It is well understood that interactions between smoke particles and cloud droplets modify cloud cover , which in turn affects climate, however, few studies have observed the temporal nature of aerosol-cloud interactions without the use of a model. Here we apply a novel approach to measure the effect of fire aerosols on convective clouds in tropical regions (Brazil, Africa and Indonesia) through a combination of remote sensing and meteorological data. We attribute a reduction in cloud fraction during periods of high aerosol optical depths to a smoke-driven inhibition of convection. We find that higher smoke burdens limit vertical updrafts, increase surface pressure, and increase low- level divergence-meteorological indicators of convective suppression. These results are corroborated by climate model simulations that show a smoke-driven increase in regionally averaged shortwave tropospheric heating and boundary layer stratification, and a decrease in vertical velocity and precipitation during the fire season (December-February). We then quantify the human response to decreased cloud cover using a combination of socioeconomic and climate data Our results suggest that, in tropical regions, anthropogenic fire initiates a positive feedback loop where increased aerosol emissions limit convection, dry the surface and enable increased fire activity via human ignition. This result has far-reaching implications for fire management and climate policy in emerging countries along the equator that utilize fire.

  15. Genomic-based-breeding tools for tropical maize improvement.

    Science.gov (United States)

    Chakradhar, Thammineni; Hindu, Vemuri; Reddy, Palakolanu Sudhakar

    2017-12-01

    Maize has traditionally been the main staple diet in the Southern Asia and Sub-Saharan Africa and widely grown by millions of resource poor small scale farmers. Approximately, 35.4 million hectares are sown to tropical maize, constituting around 59% of the developing worlds. Tropical maize encounters tremendous challenges besides poor agro-climatic situations with average yields recorded <3 tones/hectare that is far less than the average of developed countries. On the contrary to poor yields, the demand for maize as food, feed, and fuel is continuously increasing in these regions. Heterosis breeding introduced in early 90 s improved maize yields significantly, but genetic gains is still a mirage, particularly for crop growing under marginal environments. Application of molecular markers has accelerated the pace of maize breeding to some extent. The availability of array of sequencing and genotyping technologies offers unrivalled service to improve precision in maize-breeding programs through modern approaches such as genomic selection, genome-wide association studies, bulk segregant analysis-based sequencing approaches, etc. Superior alleles underlying complex traits can easily be identified and introgressed efficiently using these sequence-based approaches. Integration of genomic tools and techniques with advanced genetic resources such as nested association mapping and backcross nested association mapping could certainly address the genetic issues in maize improvement programs in developing countries. Huge diversity in tropical maize and its inherent capacity for doubled haploid technology offers advantage to apply the next generation genomic tools for accelerating production in marginal environments of tropical and subtropical world. Precision in phenotyping is the key for success of any molecular-breeding approach. This article reviews genomic technologies and their application to improve agronomic traits in tropical maize breeding has been reviewed in

  16. Tropical cyclone cooling combats region-wide coral bleaching.

    Science.gov (United States)

    Carrigan, Adam D; Puotinen, Marji

    2014-05-01

    Coral bleaching has become more frequent and widespread as a result of rising sea surface temperature (SST). During a regional scale SST anomaly, reef exposure to thermal stress is patchy in part due to physical factors that reduce SST to provide thermal refuge. Tropical cyclones (TCs - hurricanes, typhoons) can induce temperature drops at spatial scales comparable to that of the SST anomaly itself. Such cyclone cooling can mitigate bleaching across broad areas when well-timed and appropriately located, yet the spatial and temporal prevalence of this phenomenon has not been quantified. Here, satellite SST and historical TC data are used to reconstruct cool wakes (n=46) across the Caribbean during two active TC seasons (2005 and 2010) where high thermal stress was widespread. Upon comparison of these datasets with thermal stress data from Coral Reef Watch and published accounts of bleaching, it is evident that TC cooling reduced thermal stress at a region-wide scale. The results show that during a mass bleaching event, TC cooling reduced thermal stress below critical levels to potentially mitigate bleaching at some reefs, and interrupted natural warming cycles to slow the build-up of thermal stress at others. Furthermore, reconstructed TC wave damage zones suggest that it was rare for more reef area to be damaged by waves than was cooled (only 12% of TCs). Extending the time series back to 1985 (n = 314), we estimate that for the recent period of enhanced TC activity (1995-2010), the annual probability that cooling and thermal stress co-occur is as high as 31% at some reefs. Quantifying such probabilities across the other tropical regions where both coral reefs and TCs exist is vital for improving our understanding of how reef exposure to rising SSTs may vary, and contributes to a basis for targeting reef conservation. © 2014 John Wiley & Sons Ltd.

  17. Tropical deforestation: balancing regional development demands and global environmental concerns

    Energy Technology Data Exchange (ETDEWEB)

    Wood, A B [US Dept. of State, Washington, DC (USA)

    1990-01-01

    Over half of the world's tropical closed forests, which contain the greatest biodiversity, are found in just three countries: Brazil, Indonesia, and Zaire. Accelerated conversion of tropical forests is occurring because of several interlocking socio-economic and political factors: inequitable land distribution, entrenched rural poverty, and rapidly growing populations which push landless and near-landless peasants on to forest lands that are often infertile. If rates instead of absolute numbers are used to measure the severity of deforestation, Nigeria, Argentina, India, Thailand, Myanmar (Burma), Ecquador, and above all Ivory Coast stand out as countries facing an immediate deforestation crisis. Local management of forest resources, however, can be very contentious and complicated, with overlapping government agencies, competing economic interests, and ambiguous regulations. Without capital investment and entrepreneurial initiatives, residents of forest regions may have no alternative but to farm increasingly infertile soils. Non-governmental organizations, such as the World Wildlife Fund are playing leading roles in innovative debt-for-nature swaps and other forest conservation efforts. International development agencies, such as the World Bank, may play the leading role in conservation and reforestation efforts through their financial assistance programmes. The media, as a global information network, has become a powerful influence on the debate over deforestation. The Third World, bearing an increasingly heavy burden of payments to lending institutions that in 1988 surpassed 50 billion US dollars, will make a strong case that it cannot afford widespread forest conservation.

  18. Assessing the Regional Frequency, Intensity, and Spatial Extent of Tropical Cyclone Rainfall

    Science.gov (United States)

    Bosma, C.; Wright, D.; Nguyen, P.

    2017-12-01

    While the strength of a hurricane is generally classified based on its wind speed, the unprecedented rainfall-driven flooding experienced in southeastern Texas during Hurricane Harvey clearly highlights the need for better understanding of the hazards associated with extreme rainfall from hurricanes and other tropical systems. In this study, we seek to develop a framework for describing the joint probabilistic and spatio-temporal properties of extreme rainfall from hurricanes and other tropical systems. Furthermore, we argue that commonly-used terminology - such as the "500-year storm" - fail to convey the true properties of tropical cyclone rainfall occurrences in the United States. To quantify the magnitude and spatial extent of these storms, a database consisting of hundreds of unique rainfall volumetric shapes (or "voxels") was created. Each voxel is a four-dimensional object, created by connecting, in both space and time, gridded rainfall observations from the daily, gauge-based NOAA CPC-Unified precipitation dataset. Individual voxels were then associated with concurrent tropical cyclone tracks from NOAA's HURDAT-2 archive, to create distinct representations of the rainfall associated with every Atlantic tropical system making landfall over (or passing near) the United States since 1948. Using these voxels, a series of threshold-excess extreme value models were created to estimate the recurrence intervals of extreme tropical cyclone rainfall, both nationally and locally, for single and multi-day timescales. This voxel database also allows for the "indexing" of past events, placing recent extremes - such as the 50+ inches of rain observed during Hurricane Harvey - into a national context and emphasizing how rainfall totals that are rare at the point scale may be more frequent from a regional perspective.

  19. Baseline Map of Carbon Emissions from Deforestation in Tropical Regions

    Science.gov (United States)

    Harris, Nancy L.; Brown, Sandra; Hagen, Stephen C.; Saatchi, Sassan S.; Petrova, Silvia; Salas, William; Hansen, Matthew C.; Potapov, Peter V.; Lotsch, Alexander

    2012-06-01

    Policies to reduce emissions from deforestation would benefit from clearly derived, spatially explicit, statistically bounded estimates of carbon emissions. Existing efforts derive carbon impacts of land-use change using broad assumptions, unreliable data, or both. We improve on this approach using satellite observations of gross forest cover loss and a map of forest carbon stocks to estimate gross carbon emissions across tropical regions between 2000 and 2005 as 0.81 petagram of carbon per year, with a 90% prediction interval of 0.57 to 1.22 petagrams of carbon per year. This estimate is 25 to 50% of recently published estimates. By systematically matching areas of forest loss with their carbon stocks before clearing, these results serve as a more accurate benchmark for monitoring global progress on reducing emissions from deforestation.

  20. Baseline map of carbon emissions from deforestation in tropical regions.

    Science.gov (United States)

    Harris, Nancy L; Brown, Sandra; Hagen, Stephen C; Saatchi, Sassan S; Petrova, Silvia; Salas, William; Hansen, Matthew C; Potapov, Peter V; Lotsch, Alexander

    2012-06-22

    Policies to reduce emissions from deforestation would benefit from clearly derived, spatially explicit, statistically bounded estimates of carbon emissions. Existing efforts derive carbon impacts of land-use change using broad assumptions, unreliable data, or both. We improve on this approach using satellite observations of gross forest cover loss and a map of forest carbon stocks to estimate gross carbon emissions across tropical regions between 2000 and 2005 as 0.81 petagram of carbon per year, with a 90% prediction interval of 0.57 to 1.22 petagrams of carbon per year. This estimate is 25 to 50% of recently published estimates. By systematically matching areas of forest loss with their carbon stocks before clearing, these results serve as a more accurate benchmark for monitoring global progress on reducing emissions from deforestation.

  1. Floristics and biogeography of vegetation in seasonally dry tropical regions

    DEFF Research Database (Denmark)

    Dexter, K.G.; Smart, B.; Baldauf, C.

    2015-01-01

    To provide an inter-continental overview of the floristics and biogeography of drought-adapted tropical vegetation formations, we compiled a dataset of inventory plots in South America (n=93), Africa (n=84), and Asia (n=92) from savannas (subject to fire), seasonally dry tropical forests (not...... similar vegetation formations (e.g. savannas) are floristically highly dissimilar. Neotropical moist forest, savanna and seasonally dry tropical forest are floristically distinct, but elsewhere there is no clear floristic division of savanna and seasonally dry tropical forest, though moist and dry...... of the ecology, biology and conservation of savannas and seasonally dry tropical forests may be difficult....

  2. Rewilding the tropics, and other conservation translocations strategies in the tropical Asia-Pacific region

    Science.gov (United States)

    Louys, Julien; Corlett, Richard T; Price, Gilbert J; Hawkins, Stuart; Piper, Philip J

    2014-01-01

    Alarm over the prospects for survival of species in a rapidly changing world has encouraged discussion of translocation conservation strategies that move beyond the focus of ‘at-risk’ species. These approaches consider larger spatial and temporal scales than customary, with the aim of recreating functioning ecosystems through a combination of large-scale ecological restoration and species introductions. The term ‘rewilding’ has come to apply to this large-scale ecosystem restoration program. While reintroductions of species within their historical ranges have become standard conservation tools, introductions within known paleontological ranges—but outside historical ranges—are more controversial, as is the use of taxon substitutions for extinct species. Here, we consider possible conservation translocations for nine large-bodied taxa in tropical Asia-Pacific. We consider the entire spectrum of conservation translocation strategies as defined by the IUCN in addition to rewilding. The taxa considered are spread across diverse taxonomic and ecological spectra and all are listed as ‘endangered’ or ‘critically endangered’ by the IUCN in our region of study. They all have a written and fossil record that is sufficient to assess past changes in range, as well as ecological and environmental preferences, and the reasons for their decline, and they have all suffered massive range restrictions since the late Pleistocene. General principles, problems, and benefits of translocation strategies are reviewed as case studies. These allowed us to develop a conservation translocation matrix, with taxa scored for risk, benefit, and feasibility. Comparisons between taxa across this matrix indicated that orangutans, tapirs, Tasmanian devils, and perhaps tortoises are the most viable taxa for translocations. However, overall the case studies revealed a need for more data and research for all taxa, and their ecological and environmental needs. Rewilding the Asian

  3. Comparisons of invasive plants in southern Africa originating from southern temperate, northern temperate and tropical regions

    Directory of Open Access Journals (Sweden)

    L. Henderson

    2006-08-01

    Full Text Available A subset of invasive alien plant species in southern Africa was analysed in terms of their history of introduction, rate of spread, countries/region of origin, taxonomy, growth forms, cultivated uses, weed status and current distribution in southern Africa, and comparisons made of those originating from south of the tropic of Capricorn, north of the tropic of Cancer and from the tropics. The subset of 233 species, belonging to 58 families, includes all important declared species and some potentially important species. Almost as many species originate from temperate regions (112 as from the tropics (121. Most southern temperate species came from Australia (28/36, most tropical species from tropical America (92/121 and most northern temperate species from Europe (including the Mediterranean and Asia (58/76. Transformers account for 33% of  all species. More transformers are of tropical origin (36 than of northern temperate (24 and southern temperate origin (18. However. 50% of southern temperate species are transformers, compared to 32% of northern temperate and 29% of tropical species. Southern temperate transformer species are mainly woody trees and shrubs that were established on a grand scale as silvicultural crops, barriers (hedges, windbreaks and screens and cover/binders. Most aquatics, herbs, climbers and succulent shrubs an. trom the tropics. Ornamentals are the single largest category of plants from all three regions, the tropics having contributed twice as many species as temperate regions.

  4. Quantification of regional radiative impacts and climate effects of tropical fire aerosols

    Science.gov (United States)

    Tosca, M. G.; Zender, C. S.; Randerson, J. T.

    2011-12-01

    Regionally expansive smoke clouds originating from deforestation fires in Indonesia can modify local precipitation patterns via direct aerosol scattering and absorption of solar radiation (Tosca et al., 2010). Here we quantify the regional climate impacts of fire aerosols for three tropical burning regions that together account for about 70% of global annual fire emissions. We use the Community Atmosphere Model, version 5 (CAM5) coupled to a slab ocean model (SOM) embedded within the Community Earth System Model (CESM). In addition to direct aerosol radiative effects, CAM5 also quantifies indirect, semi-direct and cloud microphysical aerosol effects. Climate impacts are determined using regionally adjusted emissions data that produce realistic aerosol optical depths in CAM5. We first analyzed a single 12-year transient simulation (1996-2007) forced with unadjusted emissions estimates from the Global Fire Emissions Database, version 3 (GFEDv3) and compared the resulting aerosol optical depths (AODs) for 4 different burning regions (equatorial Asia, southern Africa, South America and boreal North America) to observed MISR and MODIS AODs for the same period. Based on this analysis we adjusted emissions for each burning region between 150 and 300% and forced a second simulation with the regionally adjusted emissions. Improved AODs from this simulation are compared to AERONET observations available at 15 stations throughout the tropics. We present here two transient simulations--one with the adjusted fire emissions and one without fires--to quantify the cumulative fire aerosol climate impact for three major tropical burning regions (equatorial Asia, southern Africa and South America). Specifically, we quantify smoke effects on radiation, precipitation, and temperature. References Tosca, M.G., J.T. Randerson, C.S. Zender, M.G. Flanner and P.J. Rasch (2010), Do biomass burning aerosols intensify drought in equatorial Asia during El Nino?, Atmos. Chem. Phys., 10, 3515

  5. Seasonality of dizziness and vertigo in a tropical region.

    Science.gov (United States)

    Pereira, Alcione Botelho; Almeida, Leonardo Alves Ferreira; Pereira, Nayara Gorette; Menezes, Patrícia Andrade Freitas de; Felipe, Lilian; Volpe, Fernando Madalena

    2015-06-01

    Vertigo and dizziness are among the most common medical complaints in the emergency room, and are associated with a considerable personal and health care burden. Scarce and conflicting reports indicate those symptoms may present a seasonal distribution. This study aimed at investigating the existence of a seasonal distribution of vertigo/dizziness in a tropical region, and the correlations of these findings with climatic variables. The charts of all patients consecutively admitted between 2009 and 2012 in the emergency room of a Brazilian general hospital were reviewed. A total of 4920 cases containing these terms were sorted from a sample of 276,076 emergency records. Seasonality was assessed using Cosinor Analysis. Pearson's correlations were performed between the incidence of consultations, considering separately dizziness and vertigo and each of the predictor climatic variables of that index month. Significant seasonal patterns were observed for dizziness and vertigo in the emergency room. Vertigo was more frequent in late winter-spring, negatively correlating to humidity (r = -0.374; p = 0.013) and rainfall (r = -0.334; p = 0.020). Dizziness peaked on summer months, and positively correlated to average temperatures (r = 0.520; p vertigo indicate possible distinct underlying mechanisms of how seasons may influence the occurrence of those symptoms.

  6. Wave ensemble forecast system for tropical cyclones in the Australian region

    Science.gov (United States)

    Zieger, Stefan; Greenslade, Diana; Kepert, Jeffrey D.

    2018-05-01

    Forecasting of waves under extreme conditions such as tropical cyclones is vitally important for many offshore industries, but there remain many challenges. For Northwest Western Australia (NW WA), wave forecasts issued by the Australian Bureau of Meteorology have previously been limited to products from deterministic operational wave models forced by deterministic atmospheric models. The wave models are run over global (resolution 1/4∘) and regional (resolution 1/10∘) domains with forecast ranges of + 7 and + 3 day respectively. Because of this relatively coarse resolution (both in the wave models and in the forcing fields), the accuracy of these products is limited under tropical cyclone conditions. Given this limited accuracy, a new ensemble-based wave forecasting system for the NW WA region has been developed. To achieve this, a new dedicated 8-km resolution grid was nested in the global wave model. Over this grid, the wave model is forced with winds from a bias-corrected European Centre for Medium Range Weather Forecast atmospheric ensemble that comprises 51 ensemble members to take into account the uncertainties in location, intensity and structure of a tropical cyclone system. A unique technique is used to select restart files for each wave ensemble member. The system is designed to operate in real time during the cyclone season providing + 10-day forecasts. This paper will describe the wave forecast components of this system and present the verification metrics and skill for specific events.

  7. Regional impacts of ocean color on tropical Pacific variability

    OpenAIRE

    W. Anderson; A. Gnanadesikan; A. Wittenberg

    2009-01-01

    The role of the penetration length scale of shortwave radiation into the surface ocean and its impact on tropical Pacific variability is investigated with a fully coupled ocean, atmosphere, land and ice model. Previous work has shown that removal of all ocean color results in a system that tends strongly towards an El Niño state. Results from a suite of surface chlorophyll perturbation experiments show that the mean state and variability of the tropical Pacific is highly se...

  8. Greenhouse Gas Emissions from Hydroelectric Reservoirs in Tropical Regions

    International Nuclear Information System (INIS)

    Pinguelli Rosa, L.; Aurelio dos Santos, M.; Oliveira dos Santos, E.; Matvienko, B.; Sikar, E.

    2004-01-01

    This paper discusses emissions by power-dams in the tropics. Greenhouse gas emissions from tropical power-dams are produced underwater through biomass decomposition by bacteria. The gases produced in these dams are mainly nitrogen, carbon dioxide and methane. A methodology was established for measuring greenhouse gases emitted by various power-dams in Brazil. Experimental measurements of gas emissions by dams were made to determine accurately their emissions of methane (CH4) and carbon dioxide (CO2) gases through bubbles formed on the lake bottom by decomposing organic matter, as well as rising up the lake gradient by molecular diffusion. The main source of gas in power-dams reservoirs is the bacterial decomposition (aerobic and anaerobic) of autochthonous and allochthonous organic matter that basically produces CO2 and CH4. The types and modes of gas production and release in the tropics are reviewed

  9. Do regions outside the tropical Pacific influence ENSO through atmospheric teleconnections?

    Digital Repository Service at National Institute of Oceanography (India)

    Dayan, H.; Izumo, T.; Vialard, J.; Lengaigne, M.; Masson, S

    This paper aims at identifying oceanic regions outside the tropical Pacific, which may influence the El Ni�o Southern Oscillation (ENSO) through interannual modulation of equatorial Pacific winds An Atmospheric General Circulation Model (AGCM) 7...

  10. Tropical Storm Ernesto Aerial Photography: Rapid Response Imagery of the Surrounding Regions After Landfall

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The imagery posted on this site is of the surrounding regions after Tropical Storm Ernesto made landfall. The aerial photography missions were conducted by the NOAA...

  11. Satellite-based Tropical Cyclone Monitoring Capabilities

    Science.gov (United States)

    Hawkins, J.; Richardson, K.; Surratt, M.; Yang, S.; Lee, T. F.; Sampson, C. R.; Solbrig, J.; Kuciauskas, A. P.; Miller, S. D.; Kent, J.

    2012-12-01

    Satellite remote sensing capabilities to monitor tropical cyclone (TC) location, structure, and intensity have evolved by utilizing a combination of operational and research and development (R&D) sensors. The microwave imagers from the operational Defense Meteorological Satellite Program [Special Sensor Microwave/Imager (SSM/I) and the Special Sensor Microwave Imager Sounder (SSMIS)] form the "base" for structure observations due to their ability to view through upper-level clouds, modest size swaths and ability to capture most storm structure features. The NASA TRMM microwave imager and precipitation radar continue their 15+ yearlong missions in serving the TC warning and research communities. The cessation of NASA's QuikSCAT satellite after more than a decade of service is sorely missed, but India's OceanSat-2 scatterometer is now providing crucial ocean surface wind vectors in addition to the Navy's WindSat ocean surface wind vector retrievals. Another Advanced Scatterometer (ASCAT) onboard EUMETSAT's MetOp-2 satellite is slated for launch soon. Passive microwave imagery has received a much needed boost with the launch of the French/Indian Megha Tropiques imager in September 2011, basically greatly supplementing the very successful NASA TRMM pathfinder with a larger swath and more frequent temporal sampling. While initial data issues have delayed data utilization, current news indicates this data will be available in 2013. Future NASA Global Precipitation Mission (GPM) sensors starting in 2014 will provide enhanced capabilities. Also, the inclusion of the new microwave sounder data from the NPP ATMS (Oct 2011) will assist in mapping TC convective structures. The National Polar orbiting Partnership (NPP) program's VIIRS sensor includes a day night band (DNB) with the capability to view TC cloud structure at night when sufficient lunar illumination exits. Examples highlighting this new capability will be discussed in concert with additional data fusion efforts.

  12. Frequency and distribution of forest, savanna, and crop fires over tropical regions during PEM-Tropics A

    Science.gov (United States)

    Olson, Jennifer R.; Baum, Bryan A.; Cahoon, Donald R.; Crawford, James H.

    1999-03-01

    Advanced very high resolution radiometer 1.1 km resolution satellite radiance data were used to locate active fires throughout much of the tropical region during NASA's Global Tropospheric Experiment (GTE) Pacific Exploratory Mission-Tropics (PEM-Tropics A) aircraft campaign, held in September and October 1996. The spatial and temporal distributions of the fires in Australia, southern Africa, and South America are presented here. The number of fires over northern Australia, central Africa, and South America appeared to decrease toward the end of the mission period. Fire over eastern Australia was widespread, and temporal patterns showed a somewhat consistent amount of burning with periodic episodes of enhanced fire counts observed. At least one episode of enhanced fire counts corresponded to the passage of a frontal system which brought conditions conducive to fire to the region, with strong westerlies originating over the hot, dry interior continent. Regions that were affected by lower than normal rainfall during the previous wet season (e.g., northern Australia and southwestern Africa) showed relatively few fires during this period. This is consistent with a drought-induced decrease in vegetation and therefore a decreased availability of fuel for burning. Alternatively, a heavier than normal previous wet season along the southeastern coast of South Africa may have contributed to high fuel loading and an associated relatively heavy amount of burning compared to data from previous years.

  13. Spatial patterns and recent trends in the climate of tropical rainforest regions.

    Science.gov (United States)

    Malhi, Yadvinder; Wright, James

    2004-03-29

    We present an analysis of the mean climate and climatic trends of tropical rainforest regions over the period 1960-1998, with the aid of explicit maps of forest cover and climatological databases. Until the mid-1970s most regions showed little trend in temperature, and the western Amazon experienced a net cooling probably associated with an interdecadal oscillation. Since the mid-1970s, all tropical rainforest regions have experienced a strong warming at a mean rate of 0.26 +/- 0.05 degrees C per decade, in synchrony with a global rise in temperature that has been attributed to the anthropogenic greenhouse effect. Over the study period, precipitation appears to have declined in tropical rainforest regions at a rate of 1.0 +/- 0.8% per decade (p Africa (at 3-4% per decade), declining marginally in tropical Asia and showing no significant trend in Amazonia. There is no evidence so far of a decline in precipitation in eastern Amazonia, a region thought vulnerable to climate-change-induced drying. The strong drying trend in Africa suggests that this should be a priority study region for understanding the impact of drought on tropical rainforests. We develop and use a dry-season index to study variations in the length and intensity of the dry season. Only African and Indian tropical rainforests appear to have seen a significant increase in dry-season intensity. In terms of interannual variability, the El Niño-Southern Oscillation (ENSO) is the primary driver of temperature variations across the tropics and of precipitation fluctuations for large areas of the Americas and southeast Asia. The relation between ENSO and tropical African precipitation appears less direct.

  14. Landslides Zonation Hazard: relation between geological structures and landslides occurrence in hilly tropical regions of Brazil.

    Science.gov (United States)

    Cerri, Rodrigo I; Reis, Fábio A G V; Gramani, Marcelo F; Giordano, Lucilia C; Zaine, José Eduardo

    2017-01-01

    This paper presents a new approach of landslides zonation hazard studies, based on an integrated study of structural data along with geomorphological and external factors, in a hilly regions of Brazil, covered by a tropical humid rain-forest, called Serra do Mar. The Serra do Mar consists of a hilly region along the east coast of Brazil, with high slopes and many geological structures in a gneiss - migmatitic terrain. In contrast to traditional approaches, this method proposes that structural data (foliation, fractures and bedding planes) and its relation with the slope geometry, is important to be consider in the landslide zonation hazard, along with declivity, relative relief, soil and rock properties, land use and vegetation cover and hydrogeological and climate factors. Results show that slopes with high hazard have the same dip direction of geological structures. Landslide zonation hazard using structural data contributes to a better understanding of how these structures, preserved in tropical residual soils, influence on slope stability and generates landslides.

  15. Landslides Zonation Hazard: relation between geological structures and landslides occurrence in hilly tropical regions of Brazil

    Directory of Open Access Journals (Sweden)

    RODRIGO I. CERRI

    2017-08-01

    Full Text Available ABSTRACT This paper presents a new approach of landslides zonation hazard studies, based on an integrated study of structural data along with geomorphological and external factors, in a hilly regions of Brazil, covered by a tropical humid rain-forest, called Serra do Mar. The Serra do Mar consists of a hilly region along the east coast of Brazil, with high slopes and many geological structures in a gneiss - migmatitic terrain. In contrast to traditional approaches, this method proposes that structural data (foliation, fractures and bedding planes and its relation with the slope geometry, is important to be consider in the landslide zonation hazard, along with declivity, relative relief, soil and rock properties, land use and vegetation cover and hydrogeological and climate factors. Results show that slopes with high hazard have the same dip direction of geological structures. Landslide zonation hazard using structural data contributes to a better understanding of how these structures, preserved in tropical residual soils, influence on slope stability and generates landslides.

  16. Linking the uncertainty of low frequency variability in tropical forcing in regional climate change

    Energy Technology Data Exchange (ETDEWEB)

    Forest, Chris E. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Meteorology; Barsugli, Joseph J. [Univ. of Colorado, Boulder, CO (United States). CIRES; Li, Wei [Pennsylvania State Univ., University Park, PA (United States). Dept. of Meteorology

    2015-02-20

    The project utilizes multiple atmospheric general circulation models (AGCMs) to examine the regional climate sensitivity to tropical sea surface temperature forcing through a series of ensemble experiments. The overall goal for this work is to use the global teleconnection operator (GTO) as a metric to assess the impact of model structural differences on the uncertainties in regional climate variability.

  17. Variations and Trends in Global and Regional Precipitation Based on the 22-year GPCP (Global Precipitation Climatology Project) and Three-year TRMM (Tropical Rainfall Measuring Mission) Data Sets

    Science.gov (United States)

    Adler, R.; Curtis, S.; Huffman, G.; Bolvin, D.; Nelkin, E.

    2001-05-01

    This paper gives an overview of the analysis of global precipitation over the last few decades and the impact of the new TRMM precipitation observations. The 20+ year, monthly, globally complete precipitation analysis of the World Climate Research Program's (WCRP/GEWEX) Global Precipitation Climatology Project (GPCP) is used to study global and regional variations and trends and is compared to the much shorter TRMM(Tropical Rainfall Measuring Mission) tropical data set. The GPCP data set shows no significant trend in global precipitation over the twenty years, unlike the positive trend in global surface temperatures over the past century. The global trend analysis must be interpreted carefully, however, because the inhomogeneity of the data set makes detecting a small signal very difficult, especially over this relatively short period. The relation of global (and tropical) total precipitation and ENSO events is quantified with no significant signal when land and ocean are combined. Identifying regional trends in precipitation may be more practical. From 1979 to 2000 the tropics have pattern of regional rainfall trends that has an ENSO-like pattern with features of both the El Nino and La Nina. This feature is related to a possible trend in the frequency of ENSO events (either El Nino or La Nina) over the past 20 years. Monthly anomalies of precipitation are related to ENSO variations with clear signals extending into middle and high latitudes of both hemispheres. The El Nino and La Nina mean anomalies are near mirror images of each other and when combined produce an ENSO signal with significant spatial continuity over large distances. A number of the features are shown to extend into high latitudes. Positive anomalies extend in the Southern Hemisphere (S.H.) from the Pacific southeastward across Chile and Argentina into the south Atlantic Ocean. In the Northern Hemisphere (N.H.) the counterpart feature extends across the southern U.S. and Atlantic Ocean into Europe

  18. Trends and changes in tropical and summer days at the Adana Sub-Region of the Mediterranean Region, Southern Turkey

    Science.gov (United States)

    Bayer Altın, Türkan; Barak, Belma

    2017-11-01

    In this study, the long-term variability and trends of the annual and seasonal numbers of summer and tropical days of the Adana Sub-region were investigated using nonlinear and linear trend detection tests for the period 1960-2014 at 14 meteorological stations. The results suggest that the annual number of summer and tropical days was generally below the long-term average through to the end of the 1980s. In particular, positive anomaly values could be observed at all stations between the years 1993-2014. With respect to the Kruskal-Wallis homogeneity test, the significant breaking date was 1993. The rapid rise of the annual number of summer (tropical) days after this year led to the inversion of the negative trends observed from 1987 to 1992 into positive ones. The increasing trend is statistically significance at 0.01 level in Yumurtalık, Mersin and Antakya for the annual number of summer and tropical days. Dörtyol, İskenderun and Elbistan were significance at 0.01 level for tropical days. The largest positive anomalies of the summer of 2010 are observed in coastal vicinity (Mersin, Yumurtalık and İskenderun). This indicates that these settlements underwent a long-term warm period and thermal conditions due to increasing temperatures in the spring and summer months. The same conditions are found in high inner areas (Göksun and Elbistan) for tropical days. It is noticed that a tendency for greater warming occurred at stations located above 1000 m in the sub-region. The average number of warm days will increase 2-days per 100-years in southern part of the sub-region. The increasing trend in summer temperatures can be considered a potential risk, notably for human health and for economic and crop losses in the Adana Sub-region, including Çukurova, one of the most important agriculture areas of Turkey.

  19. The sensitivity of tropical convective precipitation to the direct radiative forcings of black carbon aerosols emitted from major regions

    Directory of Open Access Journals (Sweden)

    C. Wang

    2009-10-01

    Full Text Available Previous works have suggested that the direct radiative forcing (DRF of black carbon (BC aerosols are able to force a significant change in tropical convective precipitation ranging from the Pacific and Indian Ocean to the Atlantic Ocean. In this in-depth analysis, the sensitivity of this modeled effect of BC on tropical convective precipitation to the emissions of BC from 5 major regions of the world has been examined. In a zonal mean base, the effect of BC on tropical convective precipitation is a result of a displacement of ITCZ toward the forcing (warming hemisphere. However, a substantial difference exists in this effect associated with BC over different continents. The BC effect on convective precipitation over the tropical Pacific Ocean is found to be most sensitive to the emissions from Central and North America due to a persistent presence of BC aerosols from these two regions in the lowermost troposphere over the Eastern Pacific. The BC effect over the tropical Indian and Atlantic Ocean is most sensitive to the emissions from South as well as East Asia and Africa, respectively. Interestingly, the summation of these individual effects associated with emissions from various regions mostly exceeds their actual combined effect as shown in the model run driven by the global BC emissions, so that they must offset each other in certain locations and a nonlinearity of this type of effect is thus defined. It is known that anthropogenic aerosols contain many scattering-dominant constituents that might exert an effect opposite to that of absorbing BC. The combined aerosol forcing is thus likely differing from the BC-only one. Nevertheless, this study along with others of its kind that isolates the DRF of BC from other forcings provides an insight of the potentially important climate response to anthropogenic forcings particularly related to the unique particulate solar absorption.

  20. The design and application of a radiological consequence model for tropical and subtropical regions

    International Nuclear Information System (INIS)

    Domel, R.U.; Harris, F.F.; Crawford, J.

    1997-01-01

    The post Chernobyl era has seen the development of a plethora of radiological consequence models. At ANSTO, a model is being developed with a user-friendly interface which will assess the radiological consequences, after an incident, in tropical and sub-tropical climates. The model combines specific regional dispersion and deposition data to determine the dose to man via the major pathways of external and internal irradiation. The external irradiation data will need to include lifestyle information such as time spent L indoors/outdoors, the high/low activity times of the different groups of people (especially critical groups) and shielding factors for housing. The internal irradiation data requires food consumption values, effect of food processing and transfer parameters (soil to plant, plant to animal) to be obtained for tropical and sub-tropical regions. The model allows the user to specify the radionuclide of interest, the age of the person receiving l the dose, race, dietary components and lifestyle. The operator may use a number of default categories, but regional information may also be entered and incorporated into the radiological model allowing assessment of dose to critical groups using site specific data. Initially, the model will deal with the South East Asian region but flexibility has been incorporated into the design to allow application in other regions. A geographic information system is used for display of all input and output data allowing quick access to not only the results but also the underlying assumptions. The model also has portability across computer platforms. The model has been developed to provide a tool for directing future research, has application as a planing tool for emergency response operations but its priority lies in understanding the behaviour of radionuclides in the tropical and sub-tropical environments and their effect on humankind

  1. Interannual-to-decadal air-sea interactions in the tropical Atlantic region

    Science.gov (United States)

    Ruiz-Barradas, Alfredo

    2001-09-01

    The present research identifies modes of atmosphere-ocean interaction in the tropical Atlantic region and the mechanisms by which air-sea interactions influence the regional climate. Novelties of the present work are (1)the use of relevant ocean and atmosphere variables important to identity coupled variability in the system. (2)The use of new data sets, including realistic diabatic heating. (3)The study of interactions between ocean and atmosphere relevant at interannual-to-decadal time scales. Two tropical modes of variability are identified during the period 1958-1993, the Atlantic Niño mode and the Interhemispheric mode. Those modes have defined structures in both ocean and atmosphere. Anomalous sea surface temperatures and winds are associated to anomalous placement of the Intertropical Convergence Zone (ITCZ). They develop maximum amplitude during boreal summer and spring, respectively. The anomalous positioning of the ITCZ produces anomalous precipitation in some places like Nordeste, Brazil and the Caribbean region. Through the use of a diagnostic primitive equation model, it is found that the most important terms controlling local anomalous surface winds over the ocean are boundary layer temperature gradients and diabatic heating anomalies at low levels (below 780 mb). The latter is of particular importance in the deep tropics in producing the anomalous meridional response to the surface circulation. Simulated latent heat anomalies indicate that a thermodynamic feedback establishes positive feedbacks at both sides of the equator and west of 20°W in the deep tropics and a negative feedback in front of the north west coast of Africa for the Interhemispheric mode. This thermodynamic feedback only establishes negative feedbacks for the Atlantic Niño mode. Transients establish some connection between the tropical Atlantic and other basins. Interhemispheric gradients of surface temperature in the tropical Atlantic influence winds in the midlatitude North

  2. Application of automated blind for daylighting in tropical region

    International Nuclear Information System (INIS)

    Chaiwiwatworakul, Pipat; Chirarattananon, Surapong; Rakkwamsuk, Pattana

    2009-01-01

    This paper reports an experimental and simulation study on application of automated Venetian blind for daylighting in tropical climate. A horizontal blind system operating automatically under programmed control was constructed and integrated onto the glazed windows to form a window system with an automated blind in a room of a laboratory building. A dimming controller was also integrated to the lighting system of the room. Different operation schemes of the window system were devised and tested in the attempt to maximize energy savings while maintaining the quality of the visual environment in the room. Intensive measurement of illuminance of the interior space was undertaken during the experiments. A methodology for calculation of interior daylight illuminance and associated glare corresponding to the configurations of the experiments was adopted. The method was coded into a computer program. Results of calculation from the program agree well with those from experiments for all the schemes of operation conducted. The program was used to simulate the situation when each scheme of operation was implemented for a whole year. It was found that such window system with automated blind enabled energy savings of 80%, but a more sophisticated scheme also helped maintain the interior visual quality at high level.

  3. Environmental stewardship for gold mining in tropical regions

    Directory of Open Access Journals (Sweden)

    A Isahak

    2013-10-01

    Full Text Available Mining has gained strong popularity in recent years due to the increase in global demand for metals and other industrial raw material derived from the ground. However, information and good governance regarding activities related to mining is still very much lacking especially in underdeveloped and developing countries in the tropics. In Malaysia, the importance of environmental stewardship in mining is a new phenomenon. The new National Mineral Policy 2 calls for compliance with existing standards and guidelines, stresses on progressive and post mining rehabilitation as well as promotes the gathering and dissemination of information, best mining practices, public disclosure and corporate social responsibility. Our preliminary studies however have shown that its implementation may have been hampered by inadequate legal and administrative structures, lack of freedom of information, physical inaccessibility, lack of information and public participation. In this presentation, the above issues and measures to reduce the impact of mining, particularly that of gold on the environment with a special focus on Malaysia is discussed. These measures include alternative gold extraction methods, appropriate tailing dam construction and management, health risk assessment and risk management, compliance with the Cyanide Code and liberalization of access to information, facilitation of access to justice, the strengthening of legal and administrative structures as well as corporate accountability to the public as part of corporate social responsibility.

  4. Ozone phytotoxicity evaluation and prediction of crops production in tropical regions

    Science.gov (United States)

    Mohammed, Nurul Izma; Ramli, Nor Azam; Yahya, Ahmad Shukri

    2013-04-01

    Increasing ozone concentration in the atmosphere can threaten food security due to its effects on crop production. Since the 1980s, ozone has been believed to be the most damaging air pollutant to crops. In Malaysia, there is no index to indicate the reduction of crops due to the exposure of ozone. Therefore, this study aimed to identify the accumulated exposure over a threshold of X ppb (AOTX) indexes in assessing crop reduction in Malaysia. In European countries, crop response to ozone exposure is mostly expressed as AOT40. This study was designed to evaluate and predict crop reduction in tropical regions and in particular, the Malaysian climate, by adopting the AOT40 index method and modifying it based on Malaysian air quality and crop data. Nine AOTX indexes (AOT0, AOT5, AOT10, AOT15, AOT20, AOT25, AOT30, AOT40, and AOT50) were analyzed, crop responses tested and reduction in crops predicted. The results showed that the AOT50 resulted in the highest reduction in crops and the highest R2 value between the AOT50 and the crops reduction from the linear regression analysis. Hence, this study suggests that the AOT50 index is the most suitable index to estimate the potential ozone impact on crops in tropical regions. The result showed that the critical level for AOT50 index if the estimated crop reduction is 5% was 1336 ppb h. Additionally, the results indicated that the AOT40 index in Malaysia gave a minimum percentage of 6% crop reduction; as contrasted with the European guideline of 5% (due to differences in the climate e.g., average amount of sunshine).

  5. High-resolution mapping of biomass burning emissions in tropical regions across three continents

    Science.gov (United States)

    Shi, Yusheng; Matsunaga, Tsuneo; Saito, Makoto

    2015-04-01

    Biomass burning emissions from open vegetation fires (forest fires, savanna fires, agricultural waste burning), human waste and biofuel combustion contain large amounts of trace gases (e.g., CO2, CH4, and N2O) and aerosols (BC and OC), which significantly impact ecosystem productivity, global atmospheric chemistry, and climate . With the help of recently released satellite products, biomass density based on satellite and ground-based observation data, and spatial variable combustion factors, this study developed a new high-resolution emissions inventory for biomass burning in tropical regions across three continents in 2010. Emissions of trace gases and aerosols from open vegetation burning are estimated from burned areas, fuel loads, combustion factors, and emission factors. Burned areas were derived from MODIS MCD64A1 burned area product, fuel loads were mapped from biomass density data sets for herbaceous and tree-covered land based on satellite and ground-based observation data. To account for spatial heterogeneity in combustion factors, global fractional tree cover (MOD44B) and vegetation cover maps (MCD12Q1) were introduced to estimate the combustion factors in different regions by using their relationship with tree cover under less than 40%, between 40-60% and above 60% conditions. For emission factors, the average values for each fuel type from field measurements are used. In addition to biomass burning from open vegetation fires, the emissions from human waste (residential and dump) burning and biofuel burning in 2010 were also estimated for 76 countries in tropical regions across the three continents and then allocated into each pixel with 1 km grid based on the population density (Gridded Population of the World v3). Our total estimates for the tropical regions across the three continents in 2010 were 17744.5 Tg CO2, 730.3 Tg CO, 32.0 Tg CH4, 31.6 Tg NOx, 119.2 Tg NMOC, 6.3 Tg SO2, 9.8 NH3 Tg, 81.8 Tg PM2.5, 48.0 Tg OC, and 5.7 Tg BC, respectively. Open

  6. Soil and water pollution in a banana production region in tropical Mexico

    NARCIS (Netherlands)

    Geissen, V.; Que Ramos, F.; Bastidas-Bastidas, de P.J.; Díaz-González, G.; Bello-Mendoza, R.; Huerta-Lwanga, E.; Ruiz-Suárez, L.E.

    2010-01-01

    The effects of abundant Mancozeb (Mn, Zn— bisdithiocarbamate) applications (2.5 kg ha-1week-1 for 10 years) on soil and surface-, subsurface- and groundwater pollution were monitored in a banana production region of tropical Mexico. In soils, severe manganese accumulation was observed, wheras the

  7. Survival probability of precipitations and rain attenuation in tropical and equatorial regions

    Science.gov (United States)

    Mohebbi Nia, Masoud; Din, Jafri; Panagopoulos, Athanasios D.; Lam, Hong Yin

    2015-08-01

    This contribution presents a stochastic model useful for the generation of a long-term tropospheric rain attenuation time series for Earth space or a terrestrial radio link in tropical and equatorial heavy rain regions based on the well-known Cox-Ingersoll-Ross model previously employed in research in the fields of finance and economics. This model assumes typical gamma distribution for rain attenuation in heavy rain climatic regions and utilises the temporal dynamic of precipitation collected in equatorial Johor, Malaysia. Different formations of survival probability are also discussed. Furthermore, the correlation between these probabilities and the Markov process is determined, and information on the variance and autocorrelation function of rain events with respect to the particular characteristics of precipitation in this area is presented. The proposed technique proved to preserve the peculiarities of precipitation for an equatorial region and reproduce fairly good statistics of the rain attenuation correlation function that could help to improve the prediction of dynamic characteristics of rain fade events.

  8. Biotrop – Seameo Regional Center for Tropical Biology

    NARCIS (Netherlands)

    Sahertian-Bakhoven, P.

    1975-01-01

    The idea to establish a regional organization in order to improve the quality of education in South East Asia was conceived in a meeting of Ministers of Education and Culture in 1965. This idea took shape and was realized in an organization called the SEAMEO (South East Asian Ministers of Education

  9. The design and application of a radiological consequence model for tropical and subtropical regions

    International Nuclear Information System (INIS)

    Domel, R.U.; Harris, F.F.; Crawford, J.

    1998-01-01

    The post Chernobyl era has seen the development of a plethora of radiological consequence models. The information used in these models pertains mostly to temperate and cold climate data, with these data mostly being hard-wired into the body of the model. At the Australian Nuclear Science and Technology Organisation (ANSTO), a model is being developed with a user-friendly interface which will assess the radiological consequences, after an incident, in tropical and sub-tropical climates. The model combines specific regional data (South East Asia) with transfer parameters (soil to plant, plant to animal) obtained for tropical and sub-tropical regions. Flexibility has been incorporated into the the design of the model to allow application in other regions. Where the relevant data are not available, default temperate data are used whilst specific research will be initiated to determine the information required. A Geographic Information System (GIS) is used for the display of input and output data allowing quick access to not only the results but also to the underlying assumptions

  10. Tropical organic soils ecosystems in relation to regional water resources in southeast Asia

    Energy Technology Data Exchange (ETDEWEB)

    Armentano, T. V.

    1982-01-01

    Tropical organic soils have functioned as natural sinks for carbon, nitrogen, slfur and other nutrients for the past 4000 years or more. Topographic evolution in peat swamp forests towards greater oligotrophy has concentrated storage of the limited nutrient stock in surface soils and biota. Tropical peat systems thus share common ecosystem characteristics with northern peat bogs and certain tropical oligotrophic forests. Organic matter accumulation and high cation-exchange-capacity limit nutrient exports from undisturbed organic soils, although nutrient retention declines with increasing eutrophy and wetland productivity. Peat swamps are subject to irreversible degradation if severely altered because disturbance of vegetation, surface peats and detritus can disrupt nuttrient cycles and reduce forest recovery capacity. Drainage also greatly increases exports of nitrogen, phosphorus and other nutrients and leads to downstream eutrophication and water quality degradation. Regional planning for clean water supplies must recognize the benefits provided by natural peatlands in balancing water supplies and regulating water chemistry.

  11. IASI-derived NH3 enhancement ratios relative to CO for the tropical biomass burning regions

    Science.gov (United States)

    Whitburn, Simon; Van Damme, Martin; Clarisse, Lieven; Hurtmans, Daniel; Clerbaux, Cathy; Coheur, Pierre-François

    2017-10-01

    Vegetation fires are a major source of ammonia (NH3) in the atmosphere. Their emissions are mainly estimated using bottom-up approaches that rely on uncertain emission factors. In this study, we derive new biome-specific NH3 enhancement ratios relative to carbon monoxide (CO), ERNH3 / CO (directly related to the emission factors), from the measurements of the IASI sounder onboard the Metop-A satellite. This is achieved for large tropical regions and for an 8-year period (2008-2015). We find substantial differences in the ERNH3 / CO ratios between the biomes studied, with calculated values ranging from 7 × 10-3 to 23 × 10-3. For evergreen broadleaf forest these are typically 50-75 % higher than for woody savanna and savanna biomes. This variability is attributed to differences in fuel types and size and is in line with previous studies. The analysis of the spatial and temporal distribution of the ERNH3 / CO ratio also reveals a (sometimes large) within-biome variability. On a regional level, woody savanna shows, for example, a mean ERNH3 / CO ratio for the region of Africa south of the Equator that is 40-75 % lower than in the other five regions studied, probably reflecting regional differences in fuel type and burning conditions. The same variability is also observed on a yearly basis, with a peak in the ERNH3 / CO ratio observed for the year 2010 for all biomes. These results highlight the need for the development of dynamic emission factors that take into better account local variations in fuel type and fire conditions. We also compare the IASI-derived ERNH3 / CO ratio with values reported in the literature, usually calculated from ground-based or airborne measurements. We find general good agreement in the referenced ERNH3 / CO ratio except for cropland, for which the ERNH3 / CO ratio shows an underestimation of about 2-2.5 times.

  12. SELEX-Based Screening of Exosome-Tropic RNA.

    Science.gov (United States)

    Yamashita, Takuma; Shinotsuka, Haruka; Takahashi, Yuki; Kato, Kana; Nishikawa, Makiya; Takakura, Yoshinobu

    2017-01-01

    Cell-derived nanosized vesicles or exosomes are expected to become delivery carriers for functional RNAs, such as small interfering RNA (siRNA). A method to efficiently load functional RNAs into exosomes is required for the development of exosome-based delivery carriers of functional RNAs. However, there is no method to find exosome-tropic exogenous RNA sequences. In this study, we used a systematic evolution of ligands by exponential enrichment (SELEX) method to screen exosome-tropic RNAs that can be used to load functional RNAs into exosomes by conjugation. Pooled single stranded 80-base RNAs, each of which contains a randomized 40-base sequence, were transfected into B16-BL6 murine melanoma cells and exosomes were collected from the cells. RNAs extracted from the exosomes were subjected to next round of SELEX. Cloning and sequencing of RNAs in SELEX-screened RNA pools showed that 29 of 56 clones had a typical RNA sequence. The sequence found by SELEX was enriched in exosomes after transfection to B16-BL6 cells. The results show that the SELEX-based method can be used for screening of exosome-tropic RNAs.

  13. Environmental conditioning on uranium surface distribution in the tropical region

    International Nuclear Information System (INIS)

    Silva, Heitor Evangelista da; Licinio, Marcus V.S.; Miranda, Marcio R.

    2001-01-01

    Based on a high resolution aerogammaspectrometer survey over the State of Rio de Janeiro, it is presented an associative study of equivalent uranium concentration and environmental parameters. The aspects considered in this study included geological domains like Sandys, Gnaisses, Granites, Xists; soils domains like Organic and Alluvial ones, Litolic, Glei, Podzolic, Red-yellow, Latossolo, Planossolo, Red bruizem, Cambissolo, Hidromorphic Podzol, Yellow latossolo; geomorphology (Coast Plains and River Accumulation Land, Coast Tabulators, Pomba-Muriae Rivers Spread Depression, Northern Mantiqueira, main Hills and Coastal Rock Massifs, Steep slopes and Reverses of Serra do Mar Mountain Range ,Serra dos Orgaos Mountain Range and Bocaina Tablelands), Paraiba do Sul Crests Alignment, Medium Paraiba do Sul Depression); influence of mean annual rain intensity and hydrographical categories were also evaluated. Geoprocessing of each environmental data base at the same cartographical base of uranium surface distribution was the basic methodology employed. (author)

  14. NOAA JPSS Advanced Technology Microwave Sounder (ATMS)-based Tropical Cyclone (TC) Products from NDE

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The JPSS Microwave Sounder-based Tropical Cyclone (TC) Products provide estimates of tropical cyclone maximum wind speed, minimum sea level pressure, radii of 34,...

  15. Study on Flexible Pavement Failures in Soft Soil Tropical Regions

    Science.gov (United States)

    Jayakumar, M.; Chee Soon, Lee

    2015-04-01

    Road network system experienced rapid upgrowth since ages ago and it started developing in Malaysia during the colonization of British due to its significant impacts in transportation field. Flexible pavement, the major road network in Malaysia, has been deteriorating by various types of distresses which cause descending serviceability of the pavement structure. This paper discusses the pavement condition assessment carried out in Sarawak and Sabah, Malaysia to have design solutions for flexible pavement failures. Field tests were conducted to examine the subgrade strength of existing roads in Sarawak at various failure locations, to assess the impact of subgrade strength on pavement failures. Research outcomes from field condition assessment and subgrade testing showed that the critical causes of pavement failures are inadequate design and maintenance of drainage system and shoulder cross fall, along with inadequate pavement thickness provided by may be assuming the conservative value of soil strength at optimum moisture content, whereas the exiting and expected subgrade strengths at equilibrium moisture content are far below. Our further research shows that stabilized existing recycled asphalt and base materials to use as a sub-base along with bitumen stabilized open graded base in the pavement composition may be a viable solution for pavement failures.

  16. Land-cover classification in a moist tropical region of Brazil with Landsat TM imagery.

    Science.gov (United States)

    Li, Guiying; Lu, Dengsheng; Moran, Emilio; Hetrick, Scott

    2011-01-01

    This research aims to improve land-cover classification accuracy in a moist tropical region in Brazil by examining the use of different remote sensing-derived variables and classification algorithms. Different scenarios based on Landsat Thematic Mapper (TM) spectral data and derived vegetation indices and textural images, and different classification algorithms - maximum likelihood classification (MLC), artificial neural network (ANN), classification tree analysis (CTA), and object-based classification (OBC), were explored. The results indicated that a combination of vegetation indices as extra bands into Landsat TM multispectral bands did not improve the overall classification performance, but the combination of textural images was valuable for improving vegetation classification accuracy. In particular, the combination of both vegetation indices and textural images into TM multispectral bands improved overall classification accuracy by 5.6% and kappa coefficient by 6.25%. Comparison of the different classification algorithms indicated that CTA and ANN have poor classification performance in this research, but OBC improved primary forest and pasture classification accuracies. This research indicates that use of textural images or use of OBC are especially valuable for improving the vegetation classes such as upland and liana forest classes having complex stand structures and having relatively large patch sizes.

  17. Quaternary paleoecology of aquatic Diptera in tropical and Southern Hemisphere regions, with special reference to the Chironomidae

    Science.gov (United States)

    Verschuren, Dirk; Eggermont, Hilde

    2006-08-01

    Chironomid paleoecology in north-temperate regions has made tremendous progress over the past decade, but studies in tropical and Southern Hemisphere regions remain relatively scarce. Reasons for this imbalance are (1) incomplete taxonomic knowledge of chironomid faunas outside Europe and North America, (2) a scarcity of ecological data on local species and genera that might confer bio-indicator value to them, and (3) logistic difficulties hampering the lake surveying necessary to develop paleoenvironmental calibration data sets. Thus far, most chironomid paleoecology in tropical and Southern Hemisphere regions has relied on an indicator-species approach, combining autecological information on local species of which larval morphology is known with the traditional ecological typology of chironomid genera transferred from the Holarctic region. This paper reviews work accomplished to date in tropical and temperate South America, Australia, Africa, and New Zealand, including studies on various families of non-chironomid Diptera with diagnostic fossils. Research has focused mostly on late-Glacial and Holocene climate reconstruction, less on tracing past human disturbance of aquatic ecosystems and their drainage basins. Quantitative chironomid-based paleoenvironmental reconstruction has so far been done only in Australia and Africa. These studies compensated for the lack of traditional surface-sediment calibration data sets, nowadays often the main source of quantitative information on species ecological optima and tolerances, by maximally exploiting archival species-distribution data based on live collections of adult and/or larval midges. This stimulated efforts to achieve trustworthy species-level identification of fossil chironomid remains, and, as a result, the taxonomic resolution of paleoecological studies in Australia and Africa is higher on average than that achieved in European and North American studies.

  18. Soil and water pollution in a banana production region in tropical Mexico

    OpenAIRE

    Geissen, V.; Que Ramos, F.; Bastidas-Bastidas, de, P.J.; Díaz-González, G.; Bello-Mendoza, R.; Huerta-Lwanga, E.; Ruiz-Suárez, L.E.

    2010-01-01

    The effects of abundant Mancozeb (Mn, Zn— bisdithiocarbamate) applications (2.5 kg ha-1week-1 for 10 years) on soil and surface-, subsurface- and groundwater pollution were monitored in a banana production region of tropical Mexico. In soils, severe manganese accumulation was observed, wheras the main metabolite ethylenethiourea was near the detection limit. Surface and subsurface water was highly polluted with ethylenethiourea, the main metabolite of Mancozeb (22.5 and 4.3 lg L-1, respective...

  19. Tropical Warm Semi-Arid Regions Expanding Over Temperate Latitudes In The Projected 21st Century

    Science.gov (United States)

    Rajaud, A.; de Noblet, N. I.

    2015-12-01

    Two billion people today live in drylands, where extreme climatic conditions prevail, and natural resources are limited. Drylands are expected to expand under several scenarios of climatic change. However, relevant adaptation strategies need to account for the aridity level: it conditions the equilibrium tree-cover density, ranging from deserts (hyper-arid) to dense savannas (sub-humid). Here we focus on the evolution of climatically defined warm semi-arid areas, where low-tree density covers can be maintained. We study the global repartition of these regions in the future and the bioclimatic shifts involved. We adopted a bioclimatological approach based on the Köppen climate classification. The warm semi-arid class is characterized by mean annual temperatures over 18°C and a rainfall-limitation criterion. A multi-model ensemble of CMIP5 projections for three representative concentration pathways was selected to analyze future conditions. The classification was first applied to the start, middle and end of the 20th and 21st centuries, in order to localize past and future warm semi-arid regions. Then, time-series for the classification were built to characterize trends and variability in the evolution of those regions. According to the CRU datasets, global expansion of the warm semi-arid area has already started (~+13%), following the global warming trend since the 1900s. This will continue according to all projections, most significantly so outside the tropical belt. Under the "business as usual" scenario, the global warm semi-arid area will increase by 30% and expand 12° poleward in the Northern Hemisphere, according to the multi-model mean. Drying drives the conversion from equatorial sub-humid conditions. Beyond 30° of latitude, cold semi-arid conditions become warm semi-arid through warming, and temperate conditions through combined warming and drying processes. Those various transitions may have drastic but also very distinct ecological and sociological

  20. Estimation of some comfort parameters for sleeping environments in dry-tropical sub-Saharan Africa region

    International Nuclear Information System (INIS)

    Djongyang, Noël; Tchinda, René; Njomo, Donatien

    2012-01-01

    Highlights: ► Thermal comfort in sleeping environments in the sub-Saharan Africa is presented. ► Comfort charts for the dry-tropical regions were established. ► Total insulation values for bedding systems range between 0.81 clo and 0.94 clo. ► Thermoneutral operative temperature ranges between 29.5 °C and 31.7 °C. ► Thermoneutral air temperature ranges between 27.1 °C and 29.6 °C. - Abstract: A human being spends approximately one-third of his/her life in sleep. For an efficient and peaceful rest, he/she therefore needs some level of comfort. This includes acceptable environmental parameters as well as suitable bedding systems. While the theories of thermal comfort in workplaces at daytime are currently well established, research on thermal comfort for sleeping environment at night is limited. Further studies in relation with sleep are needed. This paper presents an investigation on thermal comfort in sleeping environments in the sub-Saharan Africa region. The comfort equation used is based on the energy balance of the human body derived from Fanger’s comfort model. Comfort charts for the dry-tropical sub-Saharan Africa region were established using indoor climatic conditions collected over five years in Ouagadougou (12°22′N, 1°32′W). Results obtained show that the suitable monthly total insulation values for bedding systems in the dry-tropical regions range between 0.81 clo and 0.94 clo. The thermoneutral operative temperature range between 29 °C and 32 °C, while the thermoneutral air temperature range between 27 °C and 30 °C.

  1. Nonrandom community assembly and high temporal turnover promote regional coexistence in tropics but not temperate zone.

    Science.gov (United States)

    Freestone, Amy L; Inouye, Brian D

    2015-01-01

    A persistent challenge for ecologists is understanding the ecological mechanisms that maintain global patterns of biodiversity, particularly the latitudinal diversity gradient of peak species richness in the tropics. Spatial and temporal variation in community composition contribute to these patterns of biodiversity, but how this variation and its underlying processes change across latitude remains unresolved. Using a model system of sessile marine invertebrates across 25 degrees of latitude, from the temperate zone to the tropics, we tested the prediction that spatial and temporal patterns of taxonomic richness and composition, and the community assembly processes underlying these patterns, will differ across latitude. Specifically, we predicted that high beta diversity (spatial variation in composition) and high temporal turnover contribute to the high species richness of the tropics. Using a standardized experimental approach that controls for several confounding factors that hinder interpretation of prior studies, we present results that support our predictions. In the temperate zone, communities were more similar across spatial scales from centimeters to tens of kilometers and temporal scales up to one year than at lower latitudes. Since the patterns at northern latitudes were congruent with a null model, stochastic assembly processes are implicated. In contrast, the communities in the tropics were a dynamic spatial and temporal mosaic, with low similarity even across small spatial scales and high temporal turnover at both local and regional scales. Unlike the temperate zone, deterministic community assembly processes such as predation likely contributed to the high beta diversity in the tropics. Our results suggest that community assembly processes and temporal dynamics vary across latitude and help structure and maintain latitudinal patterns of diversity.

  2. The heating rate in the tropical tropopause region; Die Erwaermungsrate in der tropischen Tropopausenregion

    Energy Technology Data Exchange (ETDEWEB)

    Hamann, Ulrich

    2010-07-01

    The major part of the movement of air masses from the troposphere to the stratosphere takes place in the tropics. The conveyed air mass is transported with the Brewer-Dobson circulation poleward and therefore influences the global stratospheric composition. An important cause variable for the transport of air through the tropical tropopause layer (TTL) is the radiative heating, which is investigated in this work. The influence of trace gases, temperature, and cloudiness on the heating rate is quantified, especially the effect of the overlap of several cloud layers is discussed. The heating rate in the tropics is simulated for one year. Regional differences of the heating rate profile appear between convective and stably stratified regions. By means of trace gas concentrations, temperature, and heating rates it is determined that an enhanced transport of air through the TTL took place between January and April 2007. The comparison with previous works shows that accurate input data sets of trace gases, temperature, and cloudiness and exact methods for the simulation of the radiative transfer are indispensable for modeling of the heating rate with the required accuracy. (orig.)

  3. Potential lignocellulose resources and their utilization by ruminants in tropical regions

    International Nuclear Information System (INIS)

    Sansoucy, R.; Mahadevan, P.

    1983-01-01

    The nature and estimated quantities of potential lignocellulose resources in tropical regions are described. The most abundant sources of these materials are the natural grasslands, crop residues and by-products, e.g. sugar cane, cereals and fruits, and, to a limited extent, cultivated grasses, e.g. guinea and elephant grass. The availability of these resources to livestock is limited by a variety of environmental and logistic factors, e.g. seasonality of production and problems of collection and transport. Additionally, the nutritive value of pastures and fodders in the tropics is relatively lower than in temperate regions owing to their higher fibre and lower N and P content, with consequent lowering of intake and digestibility. Crop residues also have low N and high lignin contents and are generally deficient in fermentable energy, fermentable N, protein and micronutrients. The possibilities for improving the nutritive value of tropical feeds are discussed; these include supplementation with urea, molasses and minerals, good quality forage, and/or ''by-pass'' nutrients, e.g. oil cakes, and treatment by various physical, chemical or biological methods. (author)

  4. A dynamical characterization of the uncertainty in projections of regional precipitation change in the semi-arid tropics

    Science.gov (United States)

    Giannini, A.

    2016-12-01

    The uncertainty in CMIP multi-model ensembles of regional precipitation change in tropical regions is well known: taken at face value, models do not agree on the direction of precipitation change. Consequently, in adaptation discourse, either projections are discounted, e.g., by giving more relevance to temperature projections, or outcomes are grossly misrepresented, e.g., in extrapolating recent drought into the long-term future. That this is an unsatisfactory state of affairs, given the dominant role of precipitation in shaping climate-sensitive human endeavors in the tropics, is an understatement.Here I will provide a dynamical characterization of the uncertainty in regional precipitation projections that exploits the CMIP multi-model ensembles. This characterization is based on decomposing the moisture budget and relating its terms to the influence of the oceans, specifically to the roles of moisture supply and stabilization of the vertical profile. I will discuss some preliminary findings highlighting the relevance of lessons learned from seasonal-to-interannual prediction. One such lesson is to go beyond the projection taken at face value, and understand physical processes, specifically, the role of the oceans, in order to be able to make qualitative arguments, in addition to quantitative predictions. One other lesson is to abandon the search for the "best model" and exploit the multi-model ensemble to characterize "emergent constraints".

  5. Role of land use change in landslide-related sediment fluxes in tropical mountain regions

    Science.gov (United States)

    Guns, M.; Vanacker, V.; Demoulin, A.

    2012-04-01

    Tropical mountain regions are characterised by high denudation rates. Landslides are known to be recurrent phenomena in active mountain belts, but their contribution to the overall sedimentary fluxes is not yet well known. Previous studies on sedimentary cascades have mostly focused on natural environments, without considering the impact of human and/or anthropogenic disturbances on sedimentary budgets. In our work, we hypothesise that human-induced land use change might alter the sediment cascade through shifts in the landslide magnitude-frequency relationship. We have tested this assumption in the Virgen Yacu catchment (approximately 11km2), in the Ecuadorian Cordillera Occidental. Landslide inventories and land use maps were established based on a series of sequential aerial photos (1963, 1977, 1984 and 1989), a HR Landsat image (2001) and a VHR WorldView2 image (2010). Aerial photographs were ortho-rectified, and coregistred with the WorldView2 satellite image. Field campaigns were realised in 2010 and 2011 to collect field-based data on landslide type and geometry (depth, width and length). This allowed us to establish an empirical relationship between landslide area and volume, which was then applied to the landslide inventories to estimate landslide-related sediment production rates for various time periods. The contribution of landslides to the overall sediment flux of the catchment was estimated by comparing the landslide-related sediment production to the total sediment yield. The empirical landslide area-volume relationship established here for the Ecuadorian Andes is similar to that derived for the Himalayas. It suggests that landslides are the main source of sediment in this mountainous catchment. First calculations indicate that human-induced land use change alters the magnitude-frequency relationship through strong increase of small landslides.

  6. Applicability of Earth Observation for Identifying Small-Scale Mining Footprints in a Wet Tropical Region

    Directory of Open Access Journals (Sweden)

    Celso M. Isidro

    2017-09-01

    Full Text Available The unpredictable climate in wet tropical regions along with the spatial resolution limitations of some satellite imageries make detecting and mapping artisanal and small-scale mining (ASM challenging. The objective of this study was to test the utility of Pleiades and SPOT imagery with an object-based support vector machine (OB-SVM classifier for the multi-temporal remote sensing of ASM and other land cover including a large-scale mine in the Didipio catchment in the Philippines. Historical spatial data on location and type of ASM mines were collected from the field and were utilized as training data for the OB-SVM classifier. The classification had an overall accuracy between 87% and 89% for the three different images—Pleiades-1A for the 2013 and 2014 images and SPOT-6 for the 2016 image. The main land use features, particularly the Didipio large-scale mine, were well identified by the OB-SVM classifier, however there were greater commission errors for the mapping of small-scale mines. The lack of consistency in their shape and their small area relative to pixel sizes meant they were often not distinguished from other land clearance types (i.e., open land. To accurately estimate the total area of each land cover class, we calculated bias-adjusted surface areas based on misclassification values. The analysis showed an increase in small-scale mining areas from 91,000 m2—or 0.2% of the total catchment area—in March 2013 to 121,000 m2—or 0.3%—in May 2014, and then a decrease to 39,000 m2—or 0.1%—in January 2016.

  7. Insects associated with tropical foliage produced in the coffee growing region of Colombia

    Directory of Open Access Journals (Sweden)

    Luis F. Aristizábal

    2013-09-01

    Full Text Available We conducted a survey of insects and pest management practices on 34 farms growing ornamental tropical foliage plants in the central coffee region of Colombia over two years. Tropical foliage provided habitat for a diverse range of insects. In total, phytophagous or detritivorous insects from six orders, 40 families and 62 genera were collected. The most common were Hemiptera (29 genera from 16 families, followed by Coleoptera (17 genera from 4 families, Diptera (5 genera from 5 families, Lepidoptera (5 genera from 4 families, Hymenoptera (3 genera from 2 families and Orthoptera (2 genera from 2 families. The most common phytophagous species were leaf cutting ants (Atta and Acromyrmex spp., leaf beetles (Chrysomelidae, leafhoppers (Cicadellidae, stinkbugs (Pentatomidae, squash bugs (Coreidae, tree hoppers (Membracidae and plant hoppers (Fulgoridae. Beneficial insects identified from tropical foliage included predators and parasitoids amongst 5 orders, 12 families and 22 genera. The most abundant were predators among the Coccinellidae, Chrysopidae, Reduviidae, Lycidae and Formicidae but only low numbers of parasitoids (Ichneumonidae, Braconidae and Tachinidae were collected. A pest management questionnaire given to growers revealed a preponderance of reliance on broad spectrum insecticides with a smaller number of growers (approximately one third also using some biological control methods. Our survey contributes basic information regarding diversity of Neotropical insects associated with ornamental foliage plants.

  8. Synchronous fire activity in the tropical high Andes: an indication of regional climate forcing.

    Science.gov (United States)

    Román-Cuesta, R M; Carmona-Moreno, C; Lizcano, G; New, M; Silman, M; Knoke, T; Malhi, Y; Oliveras, I; Asbjornsen, H; Vuille, M

    2014-06-01

    Global climate models suggest enhanced warming of the tropical mid and upper troposphere, with larger temperature rise rates at higher elevations. Changes in fire activity are amongst the most significant ecological consequences of rising temperatures and changing hydrological properties in mountainous ecosystems, and there is a global evidence of increased fire activity with elevation. Whilst fire research has become popular in the tropical lowlands, much less is known of the tropical high Andean region (>2000 masl, from Colombia to Bolivia). This study examines fire trends in the high Andes for three ecosystems, the Puna, the Paramo and the Yungas, for the period 1982-2006. We pose three questions: (i) is there an increased fire response with elevation? (ii) does the El Niño- Southern Oscillation control fire activity in this region? (iii) are the observed fire trends human driven (e.g., human practices and their effects on fuel build-up) or climate driven? We did not find evidence of increased fire activity with elevation but, instead, a quasicyclic and synchronous fire response in Ecuador, Peru and Bolivia, suggesting the influence of high-frequency climate forcing on fire responses on a subcontinental scale, in the high Andes. ENSO variability did not show a significant relation to fire activity for these three countries, partly because ENSO variability did not significantly relate to precipitation extremes, although it strongly did to temperature extremes. Whilst ENSO did not individually lead the observed regional fire trends, our results suggest a climate influence on fire activity, mainly through a sawtooth pattern of precipitation (increased rainfall before fire-peak seasons (t-1) followed by drought spells and unusual low temperatures (t0), which is particularly common where fire is carried by low fuel loads (e.g., grasslands and fine fuel). This climatic sawtooth appeared as the main driver of fire trends, above local human influences and fuel build

  9. Diametric structure in a tropical dry forest fragment in the Cerrado Eco-Museum region, Brazil

    International Nuclear Information System (INIS)

    Imana Encinas Jose, Antunes Santana Otacilio; Rainier Imana Christian

    2011-01-01

    In a tropical dry forest area of the Brazilian central region, the DBH distribution of 742 trees ≥ 5 cm was analyzed in a 4000 m 2 area. Eighty three tree species were found, of which 25 species with more than 10 individuals were analyzed for this study. The frequency histograms were obtained through the Meyer and Gaussian equations. The DBH distribution of the population showed a negative exponential inverse J curve. Of the 25 species selected, 14 exhibited the same pattern. Eight species presented a tendency near the normal distribution while three species had an abnormal pattern. We concluded that the observed fragment is in a natural auto regenerative status.

  10. Phylogenetic classification of the world’s tropical forests

    OpenAIRE

    Slik, J. W. Ferry; Franklin, Janet; Arroyo-Rodríguez, Víctor; Field, Richard; Aguilar, Salomon; Aguirre, Nikolay; Ahumada, Jorge; Aiba, Shin-Ichiro; Alves, Luciana F.; K, Anitha; Avella, Andres; Mora, Francisco; Aymard C., Gerardo A.; Báez, Selene; Balvanera, Patricia

    2018-01-01

    Identifying and explaining regional differences in tropical forest dynamics, structure, diversity, and composition are critical for anticipating region-specific responses to global environmental change. Floristic classifications are of fundamental importance for these efforts. Here we provide a global tropical forest classification that is explicitly based on community evolutionary similarity, resulting in identification of five major tropical forest regions and their relationships: (i) Indo-...

  11. Effect of climate on the seminal characteristics of boars in a region of humid tropical forest

    International Nuclear Information System (INIS)

    Henao Restrepo, Guillermo; Trujillo Aramburo, Luis Emilio; Buritica Henao, Maria Elizabet; Sierra Perez, Carlos Ignacio; Correa Londono, Guillermo; Gonzalez Boto, Oscar Domingo

    2004-01-01

    In a region of humid tropical forest, ten boars of from 12 to 24 months of age were selected to evaluate the effect of climatic variables measured on the day of semen collection and for each of preceding 45 days. On seminal characteristics, the variability of each characteristic was separated into an intra individual component and an interindividual component, using maximum likelihood estimators (PROC VARCOMP of SAS). In order to relate the seminal characteristics with the climatic variables, morphological abnormalities were grouped according to the affected spermatic region, into head. Midsection and main section abnormalities; the other characteristics were evaluated without any modification. Possible correlations between seminal characteristics and climatic variables were evaluated. In a total of 298 ejaculates collected weekly during a period of 30 weeks, except for total volume and morphological abnormalities. The seminal characteristics presented low or moderate intra and interindividual variation and were similar to those found in other latitudes, with a tendency to present greater seminal volumes and concentrations maximum temperature minimum temperature. Range among temperatures. Relative humidity and precipitation of the day of the semen collection and on each of the preceding 45 days had low effects on the seminal characteristics. It is possible that the boars in warm humid tropical areas develop a high level of adaptation that permits an adequate testicular thermoregulation that favors the spermatogenic function of the seminiferous tubules in a way that does not perceptibly affect production the seminal quality

  12. Soil and water pollution in a banana production region in tropical Mexico.

    Science.gov (United States)

    Geissen, Violette; Ramos, Franzisco Que; de J Bastidas-Bastidas, Pedro; Díaz-González, Gilberto; Bello-Mendoza, Ricardo; Huerta-Lwanga, Esperanza; Ruiz-Suárez, Luz E

    2010-10-01

    The effects of abundant Mancozeb (Mn, Zn-bisdithiocarbamate) applications (2.5 kg ha⁻¹week⁻¹ for 10 years) on soil and surface-, subsurface- and groundwater pollution were monitored in a banana production region of tropical Mexico. In soils, severe manganese accumulation was observed, wheras the main metabolite ethylenethiourea was near the detection limit. Surface and subsurface water was highly polluted with ethylenethiourea, the main metabolite of Mancozeb (22.5 and 4.3 μg L⁻¹, respectively), but not with manganese. In deep ground water, no ethylenethiourea was detected. The level of pollution in the region presents a worrisome risk for aquatic life and for human health.

  13. Final Scientific Report for "The Interhemispheric Pattern in 20th Century and Future Abrupt Change in Regional Tropical Rainfall"

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, John C. H. [University of California, Berkeley, CA (United States); Wehner, Michael F. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-10-29

    This is the final scientific report for grant DOE-FG02-08ER64588, "The Interhemispheric Pattern in 20th Century and Future Abrupt Change in Regional Tropical Rainfall."The project investigates the role of the interhemispheric pattern in surface temperature – i.e. the contrast between the northern and southern temperature changes – in driving rapid changes to tropical rainfall changes over the 20th century and future climates. Previous observational and modeling studies have shown that the tropical rainband – the Intertropical Convergence Zone (ITCZ) over marine regions, and the summer monsoonal rainfall over land – are sensitive to the interhemispheric thermal contrast; but that the link between the two has not been applied to interpreting long-term tropical rainfall changes over the 20th century and future.The specific goals of the project were to i) develop dynamical mechanisms to explain the link between the interhemispheric pattern to abrupt changes of West African and Asian monsoonal rainfall; ii) Undertake a formal detection and attribution study on the interhemispheric pattern in 20th century climate; and iii) assess the likelihood of changes to this pattern in the future. In line with these goals, our project has produced the following significant results: 1.We have developed a case that suggests that the well-known abrupt weakening of the West African monsoon in the late 1960s was part of a wider co-ordinated weakening of the West African and Asian monsoons, and driven from an abrupt cooling in the high latitude North Atlantic sea surface temperature at the same time. Our modeling work suggests that the high-latitude North Atlantic cooling is effective in driving monsoonal weakening, through driving a cooling of the Northern hemisphere that is amplified by positive radiative feedbacks. 2.We have shown that anthropogenic sulfate aerosols may have partially contributed to driving a progressively southward displacement of the Atlantic Intertropical

  14. An investigation of tropical Atlantic bias in a high-resolution coupled regional climate model

    Energy Technology Data Exchange (ETDEWEB)

    Patricola, Christina M.; Saravanan, R.; Hsieh, Jen-Shan [Texas A and M University, Department of Atmospheric Sciences, College Station, TX (United States); Li, Mingkui; Xu, Zhao [Texas A and M University, Department of Oceanography, College Station, TX (United States); Ocean University of China, Key Laboratory of Physical Oceanography of Ministry of Education, Qingdao (China); Chang, Ping [Texas A and M University, Department of Oceanography, College Station, TX (United States); Ocean University of China, Key Laboratory of Physical Oceanography of Ministry of Education, Qingdao (China); Second Institute of Oceanography, State Key Laboratory of Satellite Ocean Environment Dynamics, Hangzhou, Zhejiang (China)

    2012-11-15

    Coupled atmosphere-ocean general circulation models (AOGCMs) commonly fail to simulate the eastern equatorial Atlantic boreal summer cold tongue and produce a westerly equatorial trade wind bias. This tropical Atlantic bias problem is investigated with a high-resolution (27-km atmosphere represented by the Weather Research and Forecasting Model, 9-km ocean represented by the Regional Ocean Modeling System) coupled regional climate model. Uncoupled atmospheric simulations test climate sensitivity to cumulus, land-surface, planetary boundary layer, microphysics, and radiation parameterizations and reveal that the radiation scheme has a pronounced impact in the tropical Atlantic. The CAM radiation simulates a dry precipitation (up to -90%) and cold land-surface temperature (up to -8 K) bias over the Amazon related to an over-representation of low-level clouds and almost basin-wide westerly trade wind bias. The Rapid Radiative Transfer Model and Goddard radiation simulates doubled Amazon and Congo Basin precipitation rates and a weak eastern Atlantic trade wind bias. Season-long high-resolution coupled regional model experiments indicate that the initiation of the warm eastern equatorial Atlantic sea surface temperature (SST) bias is more sensitive to the local rather than basin-wide trade wind bias and to a wet Congo Basin instead of dry Amazon - which differs from AOGCM simulations. Comparisons between coupled and uncoupled simulations suggest a regional Bjerknes feedback confined to the eastern equatorial Atlantic amplifies the initial SST, wind, and deepened thermocline bias, while barrier layer feedbacks are relatively unimportant. The SST bias in some CRCM simulations resembles the typical AOGCM bias indicating that increasing resolution is unlikely a simple solution to this problem. (orig.)

  15. Timeslice experiments for understanding regional climate projections: applications to the tropical hydrological cycle and European winter circulation

    Science.gov (United States)

    Chadwick, Robin; Douville, Hervé; Skinner, Christopher B.

    2017-11-01

    A set of atmosphere-only timeslice experiments are described, designed to examine the processes that cause regional climate change and inter-model uncertainty in coupled climate model responses to CO_2 forcing. The timeslice experiments are able to reproduce the pattern of regional climate change in the coupled models, and are applied here to two cases where inter-model uncertainty in future projections is large: the tropical hydrological cycle, and European winter circulation. In tropical forest regions, the plant physiological effect is the largest cause of hydrological cycle change in the two models that represent this process. This suggests that the CMIP5 ensemble mean may be underestimating the magnitude of water cycle change in these regions, due to the inclusion of models without the plant effect. SST pattern change is the dominant cause of precipitation and circulation change over the tropical oceans, and also appears to contribute to inter-model uncertainty in precipitation change over tropical land regions. Over Europe and the North Atlantic, uniform SST increases drive a poleward shift of the storm-track. However this does not consistently translate into an overall polewards storm-track shift, due to large circulation responses to SST pattern change, which varies across the models. Coupled model SST biases influence regional rainfall projections in regions such as the Maritime Continent, and so projections in these regions should be treated with caution.

  16. Global warming hiatus contributed to the increased occurrence of intense tropical cyclones in the coastal regions along East Asia.

    Science.gov (United States)

    Zhao, Jiuwei; Zhan, Ruifen; Wang, Yuqing

    2018-04-16

    The recent global warming hiatus (GWH) was characterized by a La Niña-like cooling in the tropical Eastern Pacific accompanied with the Indian Ocean and the tropical Atlantic Ocean warming. Here we show that the recent GWH contributed significantly to the increased occurrence of intense tropical cyclones in the coastal regions along East Asia since 1998. The GWH associated sea surface temperature anomalies triggered a pair of anomalous cyclonic and anticyclonic circulations and equatorial easterly anomalies over the Northwest Pacific, which favored TC genesis and intensification over the western Northwest Pacific but suppressed TC genesis and intensification over the southeastern Northwest Pacific due to increased vertical wind shear and anticyclonic circulation anomalies. Results from atmospheric general circulation model experiments demonstrate that the Pacific La Niña-like cooling dominated the Indian Ocean and the tropical Atlantic Ocean warming in contributing to the observed GWH-related anomalous atmospheric circulation over the Northwest Pacific.

  17. Relationships between meiofaunal biodiversity and prokaryotic heterotrophic production in different tropical habitats and oceanic regions.

    Science.gov (United States)

    Pusceddu, Antonio; Gambi, Cristina; Corinaldesi, Cinzia; Scopa, Mariaspina; Danovaro, Roberto

    2014-01-01

    Tropical marine ecosystems are among the most diverse of the world oceans, so that assessing the linkages between biodiversity and ecosystem functions (BEF) is a crucial step to predict consequences of biodiversity loss. Most BEF studies in marine ecosystems have been carried out on macrobenthic diversity, whereas the influence of the meiofauna on ecosystem functioning has received much less attention. We compared meiofaunal and nematode biodiversity and prokaryotic heterotrophic production across seagrass, mangrove and reef sediments in the Caribbean, Celebes and Red Seas. For all variables we report the presence of differences among habitats within the same region, and among regions within the same habitat. In all regions, the richness of meiofaunal taxa in reef and seagrass sediments is higher than in mangrove sediments. The sediments of the Celebes Sea show the highest meiofaunal biodiversity. The composition of meiofaunal assemblages varies significantly among habitats in the same region. The nematode beta diversity among habitats within the same region is higher than the beta diversity among regions. Although one site per habitat was considered in each region, these results suggest that the composition of meiofaunal assemblages varies primarily among biogeographic regions, whereas the composition of nematode assemblages varies more considerably among habitats. Meiofauna and nematode biodiversity and prokaryotic heterotrophic production, even after the removal of covariate effects linked with longitude and the quantity and nutritional quality of organic matter, are positively and linearly linked both across regions and within each habitat type. Our results confirm that meiofauna and nematode biodiversity may influence benthic prokaryotic activity, which, in turn, implies that diversity loss could have negative impacts on ecosystem functioning in these systems.

  18. Relationships between meiofaunal biodiversity and prokaryotic heterotrophic production in different tropical habitats and oceanic regions.

    Directory of Open Access Journals (Sweden)

    Antonio Pusceddu

    Full Text Available Tropical marine ecosystems are among the most diverse of the world oceans, so that assessing the linkages between biodiversity and ecosystem functions (BEF is a crucial step to predict consequences of biodiversity loss. Most BEF studies in marine ecosystems have been carried out on macrobenthic diversity, whereas the influence of the meiofauna on ecosystem functioning has received much less attention. We compared meiofaunal and nematode biodiversity and prokaryotic heterotrophic production across seagrass, mangrove and reef sediments in the Caribbean, Celebes and Red Seas. For all variables we report the presence of differences among habitats within the same region, and among regions within the same habitat. In all regions, the richness of meiofaunal taxa in reef and seagrass sediments is higher than in mangrove sediments. The sediments of the Celebes Sea show the highest meiofaunal biodiversity. The composition of meiofaunal assemblages varies significantly among habitats in the same region. The nematode beta diversity among habitats within the same region is higher than the beta diversity among regions. Although one site per habitat was considered in each region, these results suggest that the composition of meiofaunal assemblages varies primarily among biogeographic regions, whereas the composition of nematode assemblages varies more considerably among habitats. Meiofauna and nematode biodiversity and prokaryotic heterotrophic production, even after the removal of covariate effects linked with longitude and the quantity and nutritional quality of organic matter, are positively and linearly linked both across regions and within each habitat type. Our results confirm that meiofauna and nematode biodiversity may influence benthic prokaryotic activity, which, in turn, implies that diversity loss could have negative impacts on ecosystem functioning in these systems.

  19. Regionally Varying Assessments of Tropical Width in Reanalyses and CMIP5 Models Using a Tropopause Break Metric

    Science.gov (United States)

    Homeyer, C. R.; Martin, E. R.; McKinzie, R.; McCarthy, K.

    2017-12-01

    The boundary between the tropics and the extratropics in each hemisphere is not fixed in space or time. Variations in the north-south width of the tropics are directly connected to changes in weather and climate. These fluctuations have been shown to impact tropical biodiversity, the spread of vector borne diseases, atmospheric chemistry, and additional natural and human sectors. However, there is no unanimous definition of the tropical boundary. This has led to a disagreement on the magnitude of changes in the tropical width during the past 30 years and a lack of understanding concerning its spatial and temporal variability. This study identifies the variability of the tropical width in modern reanalyses (ERA-Interim, JRA-55, CFSR, MERRA, and MERRA-2) and CMIP5 models (all models with available 6-hourly output) using a novel analysis metric: the tropopause "break" (i.e., the sharp discontinuity in tropopause altitude between the tropics and extratropics). Similarities and differences are found amongst the reanalyses, with some degree of tropical narrowing in the Eastern Pacific between 1981 and 2010. Historical simulations from the CMIP5 models agree well with the tropopause break latitudes depicted by the reanalyses, with considerable differences in estimated trends over the relatively short overlapping time period of the datasets. For future projections under the RCP8.5 scenario from 2006 to 2100, CMIP5 models generally show statistically significant increases in tropical width (at the 99% level) throughout each hemisphere, with regional variability of 1-2 degrees in poleward latitude trends. The impact of CMIP5 model grid resolution and other factors on the results of the tropopause break analysis will be discussed.

  20. Trypanosoma cruzi-infected Panstrongylus geniculatus and Rhodnius robustus adults invade households in the Tropics of Cochabamba region of Bolivia.

    Science.gov (United States)

    Rojas-Cortez, Mirko; Pinazo, Maria-Jesus; Garcia, Lineth; Arteaga, Mery; Uriona, Liliana; Gamboa, Seyla; Mejía, Carolina; Lozano, Daniel; Gascon, Joaquim; Torrico, Faustino; Monteiro, Fernando A

    2016-03-16

    There are hardly any data available on the relationships between the parasite and the vector or regarding potential reservoirs involved in the natural transmission cycle of Trypanosoma cruzi in the Tropics of Cochabamba, Bolivia. Local families from communities were responsible for the capture of triatomine specimens, following a strategic methodology based on entomological surveillance with community participation developed by the National Chagas Programme of the Ministry of Health of Bolivia. We describe the collection of adult Panstrongylus geniculatus and Rhodnius robustus naturally infected with Trypanosoma cruzi from houses and from the hospital of Villa Tunari municipality. The flagellates found in the digestive tract of P. geniculatus belong to genetic lineages or DTUs TcI and TcIII, whereas only lineage DTU TcI was found in R. robustus. The detection of these vectors infected with T. cruzi reveals the vulnerability of local communities. The results presented here highlight the risk of Chagas disease transmission in a region previously thought not to be endemic, indicating that the Tropics of Cochabamba should be placed under permanent entomological and epidemiological surveillance.

  1. Perturbations to the lower ionosphere by tropical cyclone Evan in the South Pacific Region

    Science.gov (United States)

    Kumar, Sushil; NaitAmor, Samir; Chanrion, Olivier; Neubert, Torsten

    2017-08-01

    Very low frequency (VLF) electromagnetic signals from navigational transmitters propagate worldwide in the Earth-ionosphere waveguide formed by the Earth and the electrically conducting lower ionosphere. Changes in the signal properties are signatures of variations in the conductivity of the reflecting boundary of the lower ionosphere which is located in the mesosphere and lower thermosphere, and their analysis is, therefore, a way to study processes in these remote regions. Here we present a study on amplitude perturbations of local origin on the VLF transmitter signals (NPM, NLK, NAA, and JJI) observed during tropical cyclone (TC) Evan, 9-16 December 2012 when TC was in the proximity of the transmitter-receiver links. We observed a maximum amplitude perturbation of 5.7 dB on JJI transmitter during 16 December event. From Long Wave Propagation Capability model applied to three selected events we estimate a maximum decrease in the nighttime D region reference height (H') by 5.2 km (13 December, NPM) and maximum increase in the daytime D region H' by 6.1 km and 7.5 km (14 and 16 December, JJI). The results suggest that the TC caused the neutral densities of the mesosphere and lower thermosphere to lift and sink (bringing the lower ionosphere with it), an effect that may be mediated by gravity waves generated by the TC. The perturbations were observed before the storm was classified as a TC, at a time when it was a tropical depression, suggesting the broader conclusion that severe convective storms, in general, perturb the mesosphere and the stratosphere through which the perturbations propagate.

  2. Did biogeographical processes shape the monogenean community of butterflyfishes in the tropical Indo-west Pacific region?

    Science.gov (United States)

    Reverter, M; Cribb, T H; Cutmore, S C; Bray, R A; Parravicini, V; Sasal, P

    2017-07-01

    Geographical distribution of parasite species can provide insights into the evolution and diversity of parasitic communities. Biogeography of marine parasites is poorly known, especially because it requires an understanding of host-parasite interactions, information that is rare, especially over large spatial scales. Here, we have studied the biogeographical patterns of dactylogyrid parasites of chaetodontids, one of the most well-studied fish families, in the tropical Indo-west Pacific region. Dactylogyrid parasites were collected from gills of 34 butterflyfish species (n=560) at nine localities within an approximate area of 62millionkm 2 . Thirteen dactylogyrid species were identified, with richness ranging from 6 to 12 species at individual localities. Most dactylogyrid communities were dominated by Haliotrema angelopterum or Haliotrema aurigae, for which relative abundance was negatively correlated (ρ=-0.59). Parasite richness and diversity were highest in French Polynesia and the Great Barrier Reef (Australia) and lowest in Palau. Three biogeographic regions were identified based on dactylogyrid dissimilarities: French Polynesia, characterised by the dominance of H. angelopterum, the western Pacific region dominated by H. aurigae, and Ningaloo Reef (Australia), dominated by Euryhaliotrema berenguelae. Structure of host assemblages was the main factor explaining the dissimilarity (turnover and nestedness components of the Bray-Curtis dissimilarity and overall Bray-Curtis dissimilarity) of parasite communities between localities, while environment was only significant in the turnover of parasite communities and overall dissimilarity. Spatial structure of localities explained only 10% of the turnover of parasite communities. The interaction of the three factors (host assemblages, environment and spatial structure), however, explained the highest amounts of variance of the dactylogyrid communities, indicating a strong colinearity between the factors. Our findings

  3. Precipitation isotopes link regional climate patterns to water supply in a tropical mountain forest, eastern Puerto Rico

    Science.gov (United States)

    Scholl, Martha A.; Murphy, Sheila F.

    2014-05-01

    Like many mountainous areas in the tropics, watersheds in the Luquillo Mountains of eastern Puerto Rico have abundant rainfall and stream discharge and provide much of the water supply for the densely populated metropolitan areas nearby. Projected changes in regional temperature and atmospheric dynamics as a result of global warming suggest that water availability will be affected by changes in rainfall patterns. It is essential to understand the relative importance of different weather systems to water supply to determine how changes in rainfall patterns, interacting with geology and vegetation, will affect the water balance. To help determine the links between climate and water availability, stable isotope signatures of precipitation from different weather systems were established to identify those that are most important in maintaining streamflow and groundwater recharge. Precipitation stable isotope values in the Luquillo Mountains had a large range, from fog/cloud water with δ2H, δ18O values as high as +12 ‰, -0.73 ‰ to tropical storm rain with values as low as -127 ‰, -16.8 ‰. Temporal isotope values exhibit a reverse seasonality from those observed in higher latitude continental watersheds, with higher isotopic values in the winter and lower values in the summer. Despite the higher volume of convective and low-pressure system rainfall, stable isotope analyses indicated that under the current rainfall regime, frequent trade -wind orographic showers contribute much of the groundwater recharge and stream base flow. Analysis of rain events using 20 years of 15 -minute resolution data at a mountain station (643 m) showed an increasing trend in rainfall amount, in agreement with increased precipitable water in the atmosphere, but differing from climate model projections of drying in the region. The mean intensity of rain events also showed an increasing trend. The determination of recharge sources from stable isotope tracers indicates that water supply

  4. Coupled ocean-atmosphere surface variability and its climate impacts in the tropical Atlantic region

    Science.gov (United States)

    Fontaine, B.; Janicot, Serge; Roucou, P.

    This study examines time evolution and statistical relationships involving the two leading ocean-atmosphere coupled modes of variability in the tropical Atlantic and some climate anomalies over the tropical 120°W-60°W region using selected historical files (75-y near global SSTs and precipitation over land), more recent observed data (30-y SST and pseudo wind stress in the tropical Atlantic) and reanalyses from the US National Centers for Environmental Prediction (NCEP/NCAR) reanalysis System on the period 1968-1997: surface air temperature, sea level pressure, moist static energy content at 850 hPa, precipitable water and precipitation. The first coupled mode detected through singular value decomposition of the SST and pseudo wind-stress data over the tropical Atlantic (30°N-20°S) expresses a modulation in the thermal transequatorial gradient of SST anomalies conducted by one month leading wind-stress anomalies mainly in the tropical north Atlantic during northern winter and fall. It features a slight dipole structure in the meridional plane. Its time variability is dominated by a quasi-decadal signal well observed in the last 20-30 ys and, when projected over longer-term SST data, in the 1920s and 1930s but with shorter periods. The second coupled mode is more confined to the south-equatorial tropical Atlantic in the northern summer and explains considerably less wind-stress/SST cross-covariance. Its time series features an interannual variability dominated by shorter frequencies with increased variance in the 1960s and 1970s before 1977. Correlations between these modes and the ENSO-like Nino3 index lead to decreasing amplitude of thermal anomalies in the tropical Atlantic during warm episodes in the Pacific. This could explain the nonstationarity of meridional anomaly gradients on seasonal and interannual time scales. Overall the relationships between the oceanic component of the coupled modes and the climate anomaly patterns denote thermodynamical

  5. Tropical radioecology

    CERN Document Server

    Baxter, M

    2012-01-01

    Tropical Radioecology is a guide to the wide range of scientific practices and principles of this multidisciplinary field. It brings together past and present studies in the tropical and sub-tropical areas of the planet, highlighting the unique aspects of tropical systems. Until recently, radioecological models for tropical environments have depended upon data derived from temperate environments, despite the differences of these regions in terms of biota and abiotic conditions. Since radioactivity can be used to trace environmental processes in humans and other biota, this book offers examples of studies in which radiotracers have been used to assess biokinetics in tropical biota. Features chapters, co-authored by world experts, that explain the origins, inputs, distribution, behaviour, and consequences of radioactivity in tropical and subtropical systems. Provides comprehensive lists of relevant data and identifies current knowledge gaps to allow for targeted radioecological research in the future. Integrate...

  6. Seasonal forecasting of lightning and thunderstorm activity in tropical and temperate regions of the world.

    Science.gov (United States)

    Dowdy, Andrew J

    2016-02-11

    Thunderstorms are convective systems characterised by the occurrence of lightning. Lightning and thunderstorm activity has been increasingly studied in recent years in relation to the El Niño/Southern Oscillation (ENSO) and various other large-scale modes of atmospheric and oceanic variability. Large-scale modes of variability can sometimes be predictable several months in advance, suggesting potential for seasonal forecasting of lightning and thunderstorm activity in various regions throughout the world. To investigate this possibility, seasonal lightning activity in the world's tropical and temperate regions is examined here in relation to numerous different large-scale modes of variability. Of the seven modes of variability examined, ENSO has the strongest relationship with lightning activity during each individual season, with relatively little relationship for the other modes of variability. A measure of ENSO variability (the NINO3.4 index) is significantly correlated to local lightning activity at 53% of locations for one or more seasons throughout the year. Variations in atmospheric parameters commonly associated with thunderstorm activity are found to provide a plausible physical explanation for the variations in lightning activity associated with ENSO. It is demonstrated that there is potential for accurately predicting lightning and thunderstorm activity several months in advance in various regions throughout the world.

  7. Recent Atlantic Hurricanes, Pacific Super Typhoons, and Tropical Storm Awareness in Underdeveloped Island and Coastal Regions

    Science.gov (United States)

    Plondke, D. L.

    2017-12-01

    Hurricane Harvey was the first major hurricane to make landfall in the continental U.S. in 12 years. The next tropical storm in the 2017 Atlantic Hurricane Season was Hurricane Irma, a category 5 storm and the strongest storm to strike the U.S. mainland since Hurricane Wilma in 2005. These two storms were the third and fourth in a sequence of 10 consecutive storms to reach hurricane status in this season that ranks at least seventh among the most active seasons as measured by the Accumulate Cyclone Energy (ACE) index. Assessment of damage from Harvey may prove it to be the costliest storm in U.S. history, approaching $190 billion. Irma was the first category 5 hurricane to hit the Leeward Islands, devastating island environments including Puerto Rico, the Virgin Islands, Barbuda, Saint Barthelemy, and Anguilla with sustained winds reaching at times 185 mph. Together with the two super typhoons of the 2017 Pacific season, Noru and Lan, the two Atlantic hurricanes rank among the strongest, longest-lasting tropical cyclones on record. How many more billions of dollars will be expended in recovery and reconstruction efforts following future mega-disasters comparable to those of Hurricanes Harvey and Irma? Particularly on Caribbean and tropical Pacific islands with specialized and underdeveloped economies, aging and substandard infrastructure often cannot even partially mitigate against the impacts of major hurricanes. The most frequently used measurements of storm impact are insufficient to assess the economic impact. Analysis of the storm tracks and periods of greatest storm intensity of Hurricanes Harvey and Irma, and Super Typhoons Lan and Noru, in spatial relationship with island and coastal administrative regions, shows that rainfall totals, flooded area estimates, and property/infrastructure damage dollar estimates are all quantitative indicators of storm impact, but do not measure the costs that result from lack of storm preparedness and education of residents

  8. Tropical forest mapping at regional scale using the GRFM SAR mosaics over the Amazon in South America

    NARCIS (Netherlands)

    Sgrenzaroli, M.

    2004-01-01

    The work described in this thesis concerns the estimation of tropical forest vegetation cover in the Amazon region using as data source a continental scale high resolution (100 m) radar mosaic as data source. The radar mosaic was compiled by the Jet Propulsion Laboratory (NASA JPL) using

  9. Massive post-fire flowering events in a tropical mountain region of Brazil: high episodic supply of floral resources

    Directory of Open Access Journals (Sweden)

    Abel Augusto Conceição

    2013-12-01

    Full Text Available The species Vellozia sincorana L.B.Sm. & Ayensu is key to biodiversity conservation in the tropical mountain region of Brazil. The massive post-fire flowering of this endemic species provides a large, episodic supply of floral resources, mostly nectar, to animals.

  10. Water reduction by constructed wetlands treating waste landfill leachate in a tropical region.

    Science.gov (United States)

    Ogata, Yuka; Ishigaki, Tomonori; Ebie, Yoshitaka; Sutthasil, Noppharit; Chiemchaisri, Chart; Yamada, Masato

    2015-10-01

    One of the key challenges in landfill leachate management is the prevention of environmental pollution by the overflow of untreated leachate. To evaluate the feasibility of constructed wetlands (CWs) for the treatment of waste landfill leachate in tropical regions, water reduction and pollutant removal by a CW subjected to different flow patterns (i.e., horizontal subsurface flow (HSSF) and free water surface (FWS)) were examined in both rainy and dry seasons in Thailand. A pilot-scale CW planted with cattail was installed at a landfill site in Thailand. With HSSF, the CW substantially removed pollutants from the landfill leachate without the need to harvest plants, whereas with FWS, it only slightly removed pollutants. Under both flow patterns, the CW significantly reduced the leachate volume to a greater extent than surface evaporation, which is regarded as an effect of the storage pond. Additionally, water reduction occurred regardless of season and precipitation, within the range 0-9 mm d(-1). In the case of low feeding frequency, water reduction by the CW with HSSF was lower than that with FWS. However, high feeding frequency improved water reduction by the CW with HSSF and resulted in a similar reduction to that observed with FWS, which exhibited maximum evapotranspiration. In terms of water reduction, with both HSSF in conjunction with high frequency feeding and FWS, the CW provided a high degree of evapotranspiration. However, pollutant removal efficiencies with HSSF were higher than for FWS. The present study suggested that CWs with HSSF and high frequency feeding could be useful for the prevention of uncontrollable dispersion of polluted leachate in the tropical climate zone. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Impact of spectral nudging on the downscaling of tropical cyclones in regional climate simulations

    Science.gov (United States)

    Choi, Suk-Jin; Lee, Dong-Kyou

    2016-06-01

    This study investigated the simulations of three months of seasonal tropical cyclone (TC) activity over the western North Pacific using the Advanced Research WRF Model. In the control experiment (CTL), the TC frequency was considerably overestimated. Additionally, the tracks of some TCs tended to have larger radii of curvature and were shifted eastward. The large-scale environments of westerly monsoon flows and subtropical Pacific highs were unreasonably simulated. The overestimated frequency of TC formation was attributed to a strengthened westerly wind field in the southern quadrants of the TC center. In comparison with the experiment with the spectral nudging method, the strengthened wind speed was mainly modulated by large-scale flow that was greater than approximately 1000 km in the model domain. The spurious formation and undesirable tracks of TCs in the CTL were considerably improved by reproducing realistic large-scale atmospheric monsoon circulation with substantial adjustment between large-scale flow in the model domain and large-scale boundary forcing modified by the spectral nudging method. The realistic monsoon circulation took a vital role in simulating realistic TCs. It revealed that, in the downscaling from large-scale fields for regional climate simulations, scale interaction between model-generated regional features and forced large-scale fields should be considered, and spectral nudging is a desirable method in the downscaling method.

  12. Benchmark map of forest carbon stocks in tropical regions across three continents.

    Science.gov (United States)

    Saatchi, Sassan S; Harris, Nancy L; Brown, Sandra; Lefsky, Michael; Mitchard, Edward T A; Salas, William; Zutta, Brian R; Buermann, Wolfgang; Lewis, Simon L; Hagen, Stephen; Petrova, Silvia; White, Lee; Silman, Miles; Morel, Alexandra

    2011-06-14

    Developing countries are required to produce robust estimates of forest carbon stocks for successful implementation of climate change mitigation policies related to reducing emissions from deforestation and degradation (REDD). Here we present a "benchmark" map of biomass carbon stocks over 2.5 billion ha of forests on three continents, encompassing all tropical forests, for the early 2000s, which will be invaluable for REDD assessments at both project and national scales. We mapped the total carbon stock in live biomass (above- and belowground), using a combination of data from 4,079 in situ inventory plots and satellite light detection and ranging (Lidar) samples of forest structure to estimate carbon storage, plus optical and microwave imagery (1-km resolution) to extrapolate over the landscape. The total biomass carbon stock of forests in the study region is estimated to be 247 Gt C, with 193 Gt C stored aboveground and 54 Gt C stored belowground in roots. Forests in Latin America, sub-Saharan Africa, and Southeast Asia accounted for 49%, 25%, and 26% of the total stock, respectively. By analyzing the errors propagated through the estimation process, uncertainty at the pixel level (100 ha) ranged from ± 6% to ± 53%, but was constrained at the typical project (10,000 ha) and national (>1,000,000 ha) scales at ca. ± 5% and ca. ± 1%, respectively. The benchmark map illustrates regional patterns and provides methodologically comparable estimates of carbon stocks for 75 developing countries where previous assessments were either poor or incomplete.

  13. Investigation of radiative effects of the optically thick dust layer over the Indian tropical region

    Directory of Open Access Journals (Sweden)

    S. K. Das

    2013-04-01

    Full Text Available Optical and physical properties of aerosols derived from multi-satellite observations (MODIS-Aqua, OMI-Aura, MISR-Terra, CALIOP-CALIPSO have been used to estimate radiative effects of the dust layer over southern India. The vertical distribution of aerosol radiative forcing and heating rates are calculated with 100 m resolution in the lower atmosphere, using temperature and relative humidity data from balloon-borne radiosonde observations. The present study investigates the optically thick dust layer of optical thickness 0.18 ± 0.06 at an altitude of 2.5 ± 0.7 km over Gadanki, transported from the Thar Desert, producing radiative forcing and heating rate of 11.5 ± 3.3 W m−2 and 0.6 ± 0.26 K day−1, respectively, with a forcing efficiency of 43 W m−2 and an effective heating rate of 4 K day−1 per unit dust optical depth. Presence of the dust layer increases radiative forcing by 60% and heating rate by 60 times at that altitude compared to non-dusty cloud-free days. Calculation shows that the radiative effects of the dust layer strongly depend on the boundary layer aerosol type and mass loading. An increase of 25% of heating by the dust layer is found over relatively cleaner regions than urban regions in southern India and further 15% of heating increases over the marine region. Such heating differences in free troposphere may have significant consequences in the atmospheric circulation and hydrological cycle over the tropical Indian region.

  14. Anomalous intraseasonal events in the thermocline ridge region of Southern Tropical Indian Ocean and their regional impacts

    Science.gov (United States)

    Jayakumar, A.; Gnanaseelan, C.

    2012-03-01

    The present study explores the mechanisms responsible for the strong intraseasonal cooling events in the Thermocline Ridge region of the southwestern Indian Ocean. Air sea interface and oceanic processes associated with Madden Julian Oscillation are studied using an Ocean General Circulation Model and satellite observations. Sensitivity experiments are designed to understand the ocean response to intraseasonal forcing with a special emphasis on 2002 cooling events, which recorded the strongest intraseasonal perturbations during the last well-observed decade. This event is characterized by anomalous Walker circulation over the tropical Indian Ocean and persistent intraseasonal heat flux anomaly for a longer duration than is typical for similar events (but without any favorable preconditioning of ocean basic state at the interannual timescale). The model heat budget analysis during 1996 to 2007 revealed an in-phase relationship between atmospheric fluxes associated with Madden Julian Oscillation and the subsurface oceanic processes during the intense cooling events of 2002. The strong convection, reduced shortwave radiation and increased evaporation have contributed to the upper ocean heat loss in addition to the slower propagation of active phase of convection, which supported the integration of longer duration of forcing. The sensitivity experiments revealed that dynamic response of ocean through entrainment at the intraseasonal timescale primarily controls the biological response during the event, with oceanic interannual variability playing a secondary role. This study further speculates the role of oceanic intraseasonal variability in the 2002 droughts over Indian subcontinent.

  15. Tropical cyclone-related socio-economic losses in the western North Pacific region

    Science.gov (United States)

    Welker, C.; Faust, E.

    2013-01-01

    The western North Pacific (WNP) is the area of the world most frequently affected by tropical cyclones (TCs). However, little is known about the socio-economic impacts of TCs in this region, probably because of the limited relevant loss data. Here, loss data from Munich RE's NatCatSERVICE database is used, a high-quality and widely consulted database of natural disasters. In the country-level loss normalisation technique we apply, the original loss data are normalised to present-day exposure levels by using the respective country's nominal gross domestic product at purchasing power parity as a proxy for wealth. The main focus of our study is on the question of whether the decadal-scale TC variability observed in the Northwest Pacific region in recent decades can be shown to manifest itself economically in an associated variability in losses. It is shown that since 1980 the frequency of TC-related loss events in the WNP exhibited, apart from seasonal and interannual variations, interdecadal variability with a period of about 22 yr - driven primarily by corresponding variations of Northwest Pacific TCs. Compared to the long-term mean, the number of loss events was found to be higher (lower) by 14% (9%) in the positive (negative) phase of the decadal-scale WNP TC frequency variability. This was identified for the period 1980-2008 by applying a wavelet analysis technique. It was also possible to demonstrate the same low-frequency variability in normalised direct economic losses from TCs in the WNP region. The identification of possible physical mechanisms responsible for the observed decadal-scale Northwest Pacific TC variability will be the subject of future research, even if suggestions have already been made in earlier studies.

  16. Tropical cyclone-related socio-economic losses in the western North Pacific region

    Directory of Open Access Journals (Sweden)

    C. Welker

    2013-01-01

    Full Text Available The western North Pacific (WNP is the area of the world most frequently affected by tropical cyclones (TCs. However, little is known about the socio-economic impacts of TCs in this region, probably because of the limited relevant loss data. Here, loss data from Munich RE's NatCatSERVICE database is used, a high-quality and widely consulted database of natural disasters. In the country-level loss normalisation technique we apply, the original loss data are normalised to present-day exposure levels by using the respective country's nominal gross domestic product at purchasing power parity as a proxy for wealth. The main focus of our study is on the question of whether the decadal-scale TC variability observed in the Northwest Pacific region in recent decades can be shown to manifest itself economically in an associated variability in losses. It is shown that since 1980 the frequency of TC-related loss events in the WNP exhibited, apart from seasonal and interannual variations, interdecadal variability with a period of about 22 yr – driven primarily by corresponding variations of Northwest Pacific TCs. Compared to the long-term mean, the number of loss events was found to be higher (lower by 14% (9% in the positive (negative phase of the decadal-scale WNP TC frequency variability. This was identified for the period 1980–2008 by applying a wavelet analysis technique. It was also possible to demonstrate the same low-frequency variability in normalised direct economic losses from TCs in the WNP region. The identification of possible physical mechanisms responsible for the observed decadal-scale Northwest Pacific TC variability will be the subject of future research, even if suggestions have already been made in earlier studies.

  17. A stable isotope-based approach to tropical dendroclimatology

    Science.gov (United States)

    Evans, Michael N.; Schrag, Daniel P.

    2004-08-01

    We describe a strategy for development of chronological control in tropical trees lacking demonstrably annual ring formation, using high resolution δ 18O measurements in tropical wood. The approach applies existing models of the oxygen isotopic composition of alpha-cellulose (Roden et al., 2000), a rapid method for cellulose extraction from raw wood (Brendel et al., 2000), and continuous flow isotope ratio mass spectrometry (Brenna et al., 1998) to develop proxy chronological, rainfall and growth rate estimates from tropical trees lacking visible annual ring structure. Consistent with model predictions, pilot datasets from the temperate US and Costa Rica having independent chronological control suggest that observed cyclic isotopic signatures of several permil (SMOW) represent the annual cycle of local rainfall and relative humidity. Additional data from a plantation tree of known age from ENSO-sensitive northwestern coastal Peru suggests that the 1997-8 ENSO warm phase event was recorded as an 8‰ anomaly in the δ 18O of α-cellulose. The results demonstrate reproducibility of the stable isotopic chronometer over decades, two different climatic zones, and three tropical tree genera, and point to future applications in paleoclimatology.

  18. Estuarine demersal fish assemblage from a transition region between the tropics and the subtropics of the South Atlantic

    Directory of Open Access Journals (Sweden)

    Mauricio Hostim-Silva

    2013-06-01

    Full Text Available http://dx.doi.org/10.5007/2175-7925.2013v26n3p153 Estuarine demersal fish assemblage from a transition region between the tropics and the subtropics of the South Atlantic. The coastal state of Espírito Santo is in the central region of Brazil, where biological productivity is considered low. The objective of this work is to present a current list of demersal, estuarine fish from northern Espírito Santo. This work is based on the compilation of data collected monthly using trawl nets. The ichthyofauna comprises 57 species, within 10 orders and 32 families. The family Sciaenidae has the largest number of species (8, followed by Carangidae (4 and Gerreidae (4. This coincides with what has been found for the Brazilian coast and for the coast of the South Atlantic. It is important to note that the total species richness in the estuaries of northern Espírito Santo is lower than other estuaries of the South West Atlantic coast. Most of the species are widely distributed in the Western Atlantic. Only a small part (14% of the fauna of northern Espírito Santo was evaluated in regards to risk of extinction, but conservation should be prioritized in the area due to overexploitation of species.

  19. An Analysis of the Energetics of Tropical and Extra-Tropical Regions for Warm ENSO Composite Episodes

    Directory of Open Access Journals (Sweden)

    Zayra Christine Sátyro

    Full Text Available Abstract This study focuses on the quantification and evaluation of the effects of ENSO (El Niño Southern Oscillation warm phases, using a composite of five intense El Niño episodes between 1979 – 2011 on the Energetic Lorenz Cycle for four distinct regions around the globe: 80° S – 5° N (region 1, 50° S – 5° N (region 2, 30° S – 5° N (region 3, and 30° S – 30° N (region 4, using Data from NCEP reanalysis-II. Briefly, the results showed that zonal terms of potential energy and kinetic energy were intensified, except for region 1, where zonal kinetic energy weakened. Through the analysis of the period in which higher energy production is observed, a strong communication between the available zonal potential and the zonal kinetic energy reservoirs can be identified. This communication weakened the modes linked to eddies of potential energy and kinetic energy, as well as in the other two baroclinic conversions terms. Furthermore, the results indicate that for all the regions, the system itself works to regain its stable condition.

  20. Effects of land-use changes on evapotranspiration of tropical rain forest margin area in Central Sulawesi (Indonesia): Modelling study with a regional SVAT model

    DEFF Research Database (Denmark)

    Olchev, A.; Ibrom, Andreas; Priess, J.

    2008-01-01

    The impact of deforestation and land-use changes on evapotranspiration of mountainous tropical rain forest area in the northern part of the Lore-Lindu National Park (LLNP) in Central Sulawesi (Indonesia) was quantified using a regional process-based SVAT model "SVAT-Regio". Description...... of the areas covered by tropical rain forests, i.e. about 15%, and an increase of agricultural (coffee plantations, corn and rice fields) and urban areas. Moreover, the scenario assumes a small increase of grassland areas as well. The results of modelling experiments show that 15% deforestation of the study......, and lowest in sunny and dry days. (c) 2007 Elsevier B.V. All rights reserved....

  1. Possible developments for ex situ phytoremediation of contaminated sediments, in tropical and subtropical regions - Review.

    Science.gov (United States)

    Pittarello, Marco; Busato, Jader Galba; Carletti, Paolo; Dobbss, Leonardo Barros

    2017-09-01

    The growing problem of remediation of contaminated sediments dredged from harbor channels needs to be resolved by a cost effective and sustainable technology. Phytoremediation, by ex situ remediation plants, seems to have the potential to replace traditional methods in case of moderately contaminated sediments. On the other side, the need to mix sediments with soil and/or sand to allow an easier establishment of most employed species causes an increase of the volume of the processed substrate up to 30%. Moreover the majority of phytoremediating species are natives of temperate climate belt. Mangroves, with a special focus on the genus Avicennia - a salt secreting species - should represent an effective alternative in terms of adaptation to salty, anoxic sediments and an opportunity to develop ex situ phytoremediation plants in tropical and subtropical regions. The use of humic acid to increase root development, cell antioxidant activity and the potential attenuation of the "heavy metals exclusion strategy" to increase phytoextraction potentials of mangroves will be reviewed. Copyright © 2017. Published by Elsevier Ltd.

  2. Biological nitrogen fixation in the oxygen-minimum region of the eastern tropical North Pacific ocean.

    Science.gov (United States)

    Jayakumar, Amal; Chang, Bonnie X; Widner, Brittany; Bernhardt, Peter; Mulholland, Margaret R; Ward, Bess B

    2017-10-01

    Biological nitrogen fixation (BNF) was investigated above and within the oxygen-depleted waters of the oxygen-minimum zone of the Eastern Tropical North Pacific Ocean. BNF rates were estimated using an isotope tracer method that overcame the uncertainty of the conventional bubble method by directly measuring the tracer enrichment during the incubations. Highest rates of BNF (~4 nM day -1 ) occurred in coastal surface waters and lowest detectable rates (~0.2 nM day -1 ) were found in the anoxic region of offshore stations. BNF was not detectable in most samples from oxygen-depleted waters. The composition of the N 2 -fixing assemblage was investigated by sequencing of nifH genes. The diazotrophic assemblage in surface waters contained mainly Proteobacterial sequences (Cluster I nifH), while both Proteobacterial sequences and sequences with high identities to those of anaerobic microbes characterized as Clusters III and IV type nifH sequences were found in the anoxic waters. Our results indicate modest input of N through BNF in oxygen-depleted zones mainly due to the activity of proteobacterial diazotrophs.

  3. Photovoltaic Systems with and without Radiation Concentrators for Temperate and Tropical Regions

    Directory of Open Access Journals (Sweden)

    Vania Reis de Souza Sant’Anna

    2015-11-01

    Full Text Available The industrial development of solar photovoltaic technology has attracted investors and influenced governments to establish public policies for the sector. The present research consisted of studying, building and testing low concentration solar radiation systems for photovoltaic energy conversion. The study used optical nonimaging parameters for the V-trough type radiation concentrator constructed of anodized aluminum, to reflect and to cool. Designed to concentrate radiation by about two times and consisting of a set of photovoltaic modules connected in parallel, they were modeled in the Laboratory of Energy Area in the Department of Agricultural Engineering of the Federal University of Vicosa, Brazil, at the coordinates 20°45′14′′ S latitude, 42°52′53′′ W longitude and altitude 648.74 m. They were installed to the geographic North, with the same slope as the local latitude. For comparative analysis, it was determined the electrical characteristics for evaluation of the prototype’s performance with and without radiation concentration, the final productivity for cities in tropical and temperate regions and economic analysis for the system. It was concluded that the prototypes allowed for a gain of energy with concentration, about 31.3% more, and therefore a productivity gain for the analyzed cities in, kWh·kWp−1.

  4. Indirect quantification of fine root production in a near tropical wet mountainous region

    Science.gov (United States)

    Lu, X.; Zhang, J.; Huang, C.

    2016-12-01

    The main functions of fine root (defined as diameter floristic) and external (environmental) factors into account, including litter production, canopy density (leaf area index), leaf nutrients (N, K, Ca, Mg, P), weather and/or soil physical conditions (air temperature, humidity, precipitation, solar radiation and soil moisture). The study was conducted in near tropical broadleaf (700 m asl) and conifer (1700 m asl) forests in northeastern Taiwan, generally receiving more than 4000 mm of precipitation per year. For each site, 16 50-cm long minirhizotron tubes were installed. Fine root images were acquired every three weeks. Growth and decline, newly presence and absence of fine roots were delineated by image processing algorithms to derive fine-root productivity through time. Aforementioned internal and external attributes were simultaneously collected as well. Some of these variables were highly correlated and were detrended using principal component analysis. We found that these transformed variables (mainly associated with litter production, precipitation and solar radiation) can delineate the spatiotemporal dynamics of root production well (r2 = 0.87, p = 0.443). In conclusion, this study demonstrated the feasibility of utilized aboveground variables to indirectly assess fine root growth, which could be further developed for the regional scale mapping with aid of remote sensing.

  5. A Viable Electrode Material for Use in Microbial Fuel Cells for Tropical Regions

    Directory of Open Access Journals (Sweden)

    Felix Offei

    2016-01-01

    Full Text Available Electrode materials are critical for microbial fuel cells (MFC since they influence the construction and operational costs. This study introduces a simple and efficient electrode material in the form of palm kernel shell activated carbon (AC obtained in tropical regions. The novel introduction of this material is also targeted at introducing an inexpensive and durable electrode material, which can be produced in rural communities to improve the viability of MFCs. The maximum voltage and power density obtained (under 1000 Ω load using an H-shaped MFC with AC as both anode and cathode electrode material was 0.66 V and 1.74 W/m3, respectively. The power generated by AC was as high as 86% of the value obtained with the extensively used carbon paper. Scanning electron microscopy and Denaturing Gradient Gel Electrophoresis (DGGE analysis of AC anode biofilms confirmed that electrogenic bacteria were present on the electrode surface for substrate oxidation and the formation of nanowires.

  6. Flood moderation by large reservoirs in the humid tropics of Western ghat region of Kerala, India

    Energy Technology Data Exchange (ETDEWEB)

    Abe, George [Centre for Water Resources Development and Management, Sub Centre, Kottayam South P.O, Kottayam-686 039, Kerala (India); James, E.J. [Water Institute and Dean (Research), Karunya University, Coimbatore-641 114, Tamil Nadu (India)

    2013-07-01

    Kerala State located in the humid tropics receives an average rainfall of 2810 mm. On an average 85% of this rainfall is received during the two monsoons spread from June to November. Midland and lowland regions of several of the river basins of Kerala experience severe flood events during the monsoons. Idamalayar hydro-electric project (1987) in Periyar River basin envisages flood control apart from power generation. This paper analyzes the flood moderation by Idamalayar reservoir considering the storage regime (inflow and outflow) which is subjected to a strong inter annual variability. The role of Idamalayar reservoir in controlling the monsoon floods is analyzed using daily data (1987-2010). The results of analysis show that the flood moderation by the reservoir is 92% when water storage is less than 50%. The reduction is 87% when reservoir storage is between 50 to 90% and moderation reduces to 62% when the reservoir storage is above 90%. Non-parametric trend analysis of fifty years of hydrologic data shows a reducing trend in inflow and storage during south-west monsoon which reduced spill and subsequent flood events during north-east monsoon.

  7. [Biogeographic regionalization of the mammals of tropical evergreen forests in Mesoamerica].

    Science.gov (United States)

    Olguin-Monroy, Hector C; Gutiérrez-Blando, Cirene; Rios-Muñoz, César A; León-Paniagua, Livia; Navarro-Sigüenza, Adolfo G

    2013-06-01

    Mesoamerica is a biologically complex zone that expands from Southern Mexico to extreme Northern Colombia. The biogeographical patterns and relationships of the mammalian fauna associated to the Mesoamerican Tropical Evergreen Forest (MTEF) are poorly understood, in spite of the wide distribution of this kind of habitat in the region. We compiled a complete georeferenced database of mammalian species distributed in the MTEF of specimens from museum collections and scientific literature. This database was used to create potential distribution maps through the use of environmental niche models (ENMs) by using the Genetic Algorithm for Rule-Set Production (GARP) using 22 climatic and topographic layers. Each map was used as a representation of the geographic distribution of the species and all available maps were summed to obtain general patterns of species richness in the region. Also, the maps were used to construct a presence-absence matrix in a grid of squares of 0.5 degrees of side, that was analyzed in a Parsimony Analysis of Endemicity (PAE), which resulted in a hypothesis of the biogeographic scheme in the region. We compiled a total of 41 527 records of 233 species of mammals associated to the MTEF. The maximum concentration of species richness (104-138 species) is located in the areas around the Isthmus of Tehuantepec, Northeastern Chiapas-Western Guatemala, Western Honduras, Central Nicaragua to Northwestern Costa Rica and Western Panama. The proposed regionalization indicates that mammalian faunas associated to these forests are composed of two main groups that are divided by the Isthmus of Tehuantepec in Oaxaca in: a) a Northern group that includes Sierra Madre of Chiapas-Guatemala and Yucatan Peninsula; and b) an austral group, that contains the Pacific slope of Chiapas towards the South including Central America. Some individual phylogenetic studies of mammal species in the region support the relationships between the areas of endemism proposed, which

  8. Acute coccidiosis in an organic dairy farm in tropical region, Brazil

    Directory of Open Access Journals (Sweden)

    Mônica M. Florião

    2015-12-01

    Full Text Available ABSTRACT. Florião M.M., Lopes B. do B., Berto B.P. & Lopes C.W.G. Acute coccidiosis in an organic dairy farm in tropical region, Brazil. [Coccidiose aguda em uma fazenda de gado leiteiro orgânico na região tropical, Brasil.] Revista Brasileira de Medicina Veterinária, 37(Supl.1:6-12, 2015. Curso de Pós- -Graduação em Ciência, Tecnologia e Inovação em Agropecuária, Universidade Federal Rural do Rio de Janeiro, BR 465, Km 7, Campus Seropédica, RJ 23897- 970, Brasil. E-mail: monicafloriao@hotmail.com Coccidiosis or bovine eimeriosis is an intestinal disease caused by species of the genus Eimeria Schneider, 1875. It is responsible for gastrointestinal disorders and in some cases, animals died, especially the young animals. The proposed organic management for the system was relevant in establishing the health of the studied herd. Only some of the animals had clinical signs of acute eimeriosis. In nursing calves clinical signs appeared at 30 days old, during the first period of the study (2013-2014, occurring shortly after abrupt change in management, when the amount of milk supplied to animals of this extract was reduced. The other two cases occurred during the second period of the study (2014-2015, after fire in the area of pastures, causing the batch of weaned calves come into pasture destined to cows, with such abrupt change in management developed clinical signs of acute eimeriosis. The most frequent species was E. zuernii in both extracts, followed by E. cylindrica in nursing calves, and E. bovis and E. bukidnonensis in the weaned calves. The recovery of the animals was performed with the return to the proposed organic management associated with use of homeopathic medication. In addition, the animals recovered their body weight gains established for Gir breed (zebu dairy cattle and its cross breeds.

  9. Benchmark map of forest carbon stocks in tropical regions across three continents

    Science.gov (United States)

    Saatchi, Sassan S.; Harris, Nancy L.; Brown, Sandra; Lefsky, Michael; Mitchard, Edward T. A.; Salas, William; Zutta, Brian R.; Buermann, Wolfgang; Lewis, Simon L.; Hagen, Stephen; Petrova, Silvia; White, Lee; Silman, Miles; Morel, Alexandra

    2011-01-01

    Developing countries are required to produce robust estimates of forest carbon stocks for successful implementation of climate change mitigation policies related to reducing emissions from deforestation and degradation (REDD). Here we present a “benchmark” map of biomass carbon stocks over 2.5 billion ha of forests on three continents, encompassing all tropical forests, for the early 2000s, which will be invaluable for REDD assessments at both project and national scales. We mapped the total carbon stock in live biomass (above- and belowground), using a combination of data from 4,079 in situ inventory plots and satellite light detection and ranging (Lidar) samples of forest structure to estimate carbon storage, plus optical and microwave imagery (1-km resolution) to extrapolate over the landscape. The total biomass carbon stock of forests in the study region is estimated to be 247 Gt C, with 193 Gt C stored aboveground and 54 Gt C stored belowground in roots. Forests in Latin America, sub-Saharan Africa, and Southeast Asia accounted for 49%, 25%, and 26% of the total stock, respectively. By analyzing the errors propagated through the estimation process, uncertainty at the pixel level (100 ha) ranged from ±6% to ±53%, but was constrained at the typical project (10,000 ha) and national (>1,000,000 ha) scales at ca. ±5% and ca. ±1%, respectively. The benchmark map illustrates regional patterns and provides methodologically comparable estimates of carbon stocks for 75 developing countries where previous assessments were either poor or incomplete. PMID:21628575

  10. Development of radiation processes wood-polymer composites based on tropical hardwoods

    International Nuclear Information System (INIS)

    Iya, V.K.; Majali, A.B.

    1978-01-01

    The wood-polymer composites based on tropical hardwoods were prepared with three monomer systems. Use of chlorinated paraffin oil as an additive imparted fire resistance to the composites and also brought down the gamma dose requirement for total polymerisation. A number of tropical hardwoods can be upgraded by radiation curing, but for cost optimisation, hardwoods with high improvement per unit polymer should be selected. (author)

  11. Synchronous fire activity in the tropical high Andes: an indication of regional climate forcing

    NARCIS (Netherlands)

    Roman-Cuesta, R.M.; Carmona-Moreno, C.; Lizcano, G.; New, M.; Silman, M.R.; Knoke, T.; Malhi, Y.; Oliveras Menor, I.; Asbjornsen, H.; Vuille, M.

    2014-01-01

    Global climate models suggest enhanced warming of the tropical mid and upper troposphere, with larger temperature rise rates at higher elevations. Changes in fire activity are amongst the most significant ecological consequences of rising temperatures and changing hydrological properties in

  12. On the development of a coupled regional climate-vegetation model RCM-CLM-CN-DV and its validation in Tropical Africa

    Science.gov (United States)

    Wang, Guiling; Yu, Miao; Pal, Jeremy S.; Mei, Rui; Bonan, Gordon B.; Levis, Samuel; Thornton, Peter E.

    2016-01-01

    This paper presents a regional climate system model RCM-CLM-CN-DV and its validation over Tropical Africa. The model development involves the initial coupling between the ICTP regional climate model RegCM4.3.4 (RCM) and the Community Land Model version 4 (CLM4) including models of carbon-nitrogen dynamics (CN) and vegetation dynamics (DV), and further improvements of the models. Model improvements derive from the new parameterization from CLM4.5 that addresses the well documented overestimation of gross primary production (GPP), a refinement of stress deciduous phenology scheme in CN that addresses a spurious LAI fluctuation for drought-deciduous plants, and the incorporation of a survival rule into the DV model to prevent tropical broadleaf evergreens trees from growing in areas with a prolonged drought season. The impact of the modifications on model results is documented based on numerical experiments using various subcomponents of the model. The performance of the coupled model is then validated against observational data based on three configurations with increasing capacity: RCM-CLM with prescribed leaf area index and fractional coverage of different plant functional types (PFTs); RCM-CLM-CN with prescribed PFTs coverage but prognostic plant phenology; RCM-CLM-CN-DV in which both the plant phenology and PFTs coverage are simulated by the model. Results from these three models are compared against the FLUXNET up-scaled GPP and ET data, LAI and PFT coverages from remote sensing data including MODIS and GIMMS, University of Delaware precipitation and temperature data, and surface radiation data from MVIRI and SRB. Our results indicate that the models perform well in reproducing the physical climate and surface radiative budgets in the domain of interest. However, PFTs coverage is significantly underestimated by the model over arid and semi-arid regions of Tropical Africa, caused by an underestimation of LAI in these regions by the CN model that gets exacerbated

  13. Multi-hazard risk assessment of coastal vulnerability from tropical cyclones - A GIS based approach for the Odisha coast.

    Science.gov (United States)

    Sahoo, Bishnupriya; Bhaskaran, Prasad K

    2018-01-15

    The coastal region bordering the East coast of India is a thickly populated belt exposed to high risk and vulnerability from natural hazards such as tropical cyclones. Tropical cyclone frequencies that develop over the Bay of Bengal (average of 5-6 per year) region are much higher as compared to the Arabian Sea thereby posing a high risk factor associated with storm surge, inland inundation, wind gust, intense rainfall, etc. The Odisha State in the East coast of India experiences the highest number of cyclone strikes as compared to West Bengal, Andhra Pradesh, and Tamil Nadu. To express the destructive potential resulting from tropical cyclones the Power Dissipation Index (PDI) is a widely used metric globally. A recent study indicates that PDI for cyclones in the present decade have increased about six times as compared to the past. Hence there is a need to precisely ascertain the coastal vulnerability and risk factors associated with high intense cyclones expected in a changing climate. As such there are no comprehensive studies attempted so far on the determination of Coastal Vulnerability Index (CVI) for Odisha coast that is highly prone to cyclone strikes. With this motivation, the present study makes an attempt to investigate the physical, environmental, social, and economic impacts on coastal vulnerability associated with tropical cyclones for the Odisha coast. The study also investigates the futuristic projection of coastal vulnerability over this region expected in a changing climate scenario. Eight fair weather parameters along with storm surge height and onshore inundation were used to estimate the Physical Vulnerability Index (PVI). Thereafter, the PVI along with social, economic, and environmental vulnerability was used to determine the overall CVI using the GIS based approach. The authors believe that the comprehensive nature of this study is expected to benefit coastal zone management authorities. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Development and application of a crossbreeding simulation model for goat production systems in tropical regions.

    Science.gov (United States)

    Tsukahara, Y; Oishi, K; Hirooka, H

    2011-12-01

    A deterministic simulation model was developed to estimate biological production efficiency and to evaluate goat crossbreeding systems under tropical conditions. The model involves 5 production systems: pure indigenous, first filial generations (F1), backcross (BC), composite breeds of F1 (CMP(F1)), and BC (CMP(BC)). The model first simulates growth, reproduction, lactation, and energy intakes of a doe and a kid on a 1-d time step at the individual level and thereafter the outputs are integrated into the herd dynamics program. The ability of the model to simulate individual performances was tested under a base situation. The simulation results represented daily BW changes, ME requirements, and milk yield and the estimates were within the range of published data. Two conventional goat production scenarios (an intensive milk production scenario and an integrated goat and oil palm production scenario) in Malaysia were examined. The simulation results of the intensive milk production scenario showed the greater production efficiency of the CMP(BC) and CMP(F1) systems and decreased production efficiency of the F1 and BC systems. The results of the integrated goat and oil palm production scenario showed that the production efficiency and stocking rate were greater for the indigenous goats than for the crossbreeding systems.

  15. Colour Model for Outdoor Machine Vision for Tropical Regions and its Comparison with the CIE Model

    Energy Technology Data Exchange (ETDEWEB)

    Sahragard, Nasrolah; Ramli, Abdul Rahman B [Institute of Advanced Technology, Universiti Putra Malaysia 43400 Serdang, Selangor (Malaysia); Marhaban, Mohammad Hamiruce [Department of Electrical and Electronic Engineering, Faculty of Engineering, Universiti Putra Malaysia 43400 Serdang, Selangor (Malaysia); Mansor, Shattri B, E-mail: sahragard@yahoo.com [Department of Civil Engineering, Faculty of Engineering, Universiti Putra Malaysia 43400 Serdang, Selangor (Malaysia)

    2011-02-15

    Accurate modeling of daylight and surface reflectance are very useful for most outdoor machine vision applications specifically those which are based on color recognition. Existing daylight CIE model has drawbacks that limit its ability to predict the color of incident light. These limitations include lack of considering ambient light, effects of light reflected off the ground, and context specific information. Previously developed color model is only tested for a few geographical places in North America and its accountability is under question for other places in the world. Besides, existing surface reflectance models are not easily applied to outdoor images. A reflectance model with combined diffuse and specular reflection in normalized HSV color space could be used to predict color. In this paper, a new daylight color model showing the color of daylight for a broad range of sky conditions is developed which will suit weather conditions of tropical places such as Malaysia. A comparison of this daylight color model and daylight CIE model will be discussed. The colors of matte and specular surfaces have been estimated by use of the developed color model and surface reflection function in this paper. The results are shown to be highly reliable.

  16. Colour Model for Outdoor Machine Vision for Tropical Regions and its Comparison with the CIE Model

    Science.gov (United States)

    Sahragard, Nasrolah; Ramli, Abdul Rahman B.; Hamiruce Marhaban, Mohammad; Mansor, Shattri B.

    2011-02-01

    Accurate modeling of daylight and surface reflectance are very useful for most outdoor machine vision applications specifically those which are based on color recognition. Existing daylight CIE model has drawbacks that limit its ability to predict the color of incident light. These limitations include lack of considering ambient light, effects of light reflected off the ground, and context specific information. Previously developed color model is only tested for a few geographical places in North America and its accountability is under question for other places in the world. Besides, existing surface reflectance models are not easily applied to outdoor images. A reflectance model with combined diffuse and specular reflection in normalized HSV color space could be used to predict color. In this paper, a new daylight color model showing the color of daylight for a broad range of sky conditions is developed which will suit weather conditions of tropical places such as Malaysia. A comparison of this daylight color model and daylight CIE model will be discussed. The colors of matte and specular surfaces have been estimated by use of the developed color model and surface reflection function in this paper. The results are shown to be highly reliable.

  17. Colour Model for Outdoor Machine Vision for Tropical Regions and its Comparison with the CIE Model

    International Nuclear Information System (INIS)

    Sahragard, Nasrolah; Ramli, Abdul Rahman B; Marhaban, Mohammad Hamiruce; Mansor, Shattri B

    2011-01-01

    Accurate modeling of daylight and surface reflectance are very useful for most outdoor machine vision applications specifically those which are based on color recognition. Existing daylight CIE model has drawbacks that limit its ability to predict the color of incident light. These limitations include lack of considering ambient light, effects of light reflected off the ground, and context specific information. Previously developed color model is only tested for a few geographical places in North America and its accountability is under question for other places in the world. Besides, existing surface reflectance models are not easily applied to outdoor images. A reflectance model with combined diffuse and specular reflection in normalized HSV color space could be used to predict color. In this paper, a new daylight color model showing the color of daylight for a broad range of sky conditions is developed which will suit weather conditions of tropical places such as Malaysia. A comparison of this daylight color model and daylight CIE model will be discussed. The colors of matte and specular surfaces have been estimated by use of the developed color model and surface reflection function in this paper. The results are shown to be highly reliable.

  18. Daytime tropical D region parameters from short path VLF phase and amplitude

    Science.gov (United States)

    Thomson, Neil R.

    2010-09-01

    Observed phases and amplitudes of VLF radio signals, propagating on a short (˜300-km) path, are used to find improved parameters for the lowest edge of the (D region of the) Earth's ionosphere. The phases, relative to GPS 1-s pulses, and the amplitudes were measured both near (˜100 km from) the transmitter, where the direct ground wave is very dominant, and at distances of ˜300 km near where the ionospherically reflected waves form a (modal) minimum with the (direct) ground wave. The signals came from the 19.8 kHz, 1 MW transmitter, NWC, on the North West Cape of Australia, propagating ˜300 km ENE, mainly over the sea, to the vicinity of Karratha/Dampier on the N.W. coast of Australia. The bottom edge of the mid-day tropical/equatorial ionosphere was thus found to be well-modeled by H‧ = 70.5 ± 0.5 km and β = 0.47 ± 0.03 km-1 where H‧ and β are the traditional height and sharpness parameters as used by Wait and by the U.S. Navy in their Earth-ionosphere VLF radio waveguide programs. U.S. Navy modal waveguide code calculations are also compared with those from the wave hop code of Berry and Herman (1971). At least for the vertical electric fields on the path studied here, the resulting phase and amplitude differences (between the ˜100-km and ˜300-km sites) agree very well after just a small adjustment of ˜0.2 km in H‧ between the two codes. Such short paths also allow more localization than the usual long paths; here this localization is to low latitudes.

  19. Fires in Seasonally Dry Tropical Forest: Testing the Varying Constraints Hypothesis across a Regional Rainfall Gradient.

    Science.gov (United States)

    Mondal, Nandita; Sukumar, Raman

    2016-01-01

    The "varying constraints hypothesis" of fire in natural ecosystems postulates that the extent of fire in an ecosystem would differ according to the relative contribution of fuel load and fuel moisture available, factors that vary globally along a spatial gradient of climatic conditions. We examined if the globally widespread seasonally dry tropical forests (SDTFs) can be placed as a single entity in this framework by analyzing environmental influences on fire extent in a structurally diverse SDTF landscape in the Western Ghats of southern India, representative of similar forests in monsoonal south and southeast Asia. We used logistic regression to model fire extent with factors that represent fuel load and fuel moisture at two levels-the overall landscape and within four defined moisture regimes (between 700 and1700 mm yr-1)-using a dataset of area burnt and seasonal rainfall from 1990 to 2010. The landscape scale model showed that the extent of fire in a given year within this SDTF is dependent on the combined interaction of seasonal rainfall and extent burnt the previous year. Within individual moisture regimes the relative contribution of these factors to the annual extent burnt varied-early dry season rainfall (i.e., fuel moisture) was the predominant factor in the wettest regime, while wet season rainfall (i.e., fuel load) had a large influence on fire extent in the driest regime. Thus, the diverse structural vegetation types associated with SDTFs across a wide range of rainfall regimes would have to be examined at finer regional or local scales to understand the specific environmental drivers of fire. Our results could be extended to investigating fire-climate relationships in STDFs of monsoonal Asia.

  20. Coupled social and ecological outcomes of land use change and agricultural intensification in Costa Rica and the future of biodiversity conservation in tropical agricultural regions.

    Science.gov (United States)

    Sanfiorenzo, A. R.; Shaver, I.; Chain Guadarrama, A.; Cleary, K.; Santiago-Garcia, R.; Finegan, B.; Hormel, L.; Sibelet, N.; Vierling, L. A.; Bosque-Perez, N.; DeClerck, F.; Fagan, M. E.; Waits, L.

    2017-12-01

    Tropical ecosystem conversion to agriculture has caused widespread habitat loss and created fragmented landscapes composed of remnant forest patches embedded in a matrix of agricultural land uses. Non- traditional agricultural export (NTAE) crops such as pineapple are rapidly replacing multiuse landscapes characterized by a diverse matrix of pasture and smallholder crops with intensive, large-scale, monoculture plantations. Using an interdisciplinary approach, we conduct a case study to examine the coupled social and ecological implications of LUCC and agricultural intensification in this region, with larger application to regions experiencing similar patterns. Guided by frameworks from both political and landscape ecology, we: (1) describe the social and economic implications of pineapple expansion, specifically the concentration of land, labor and financial resources, (2) quantify pineapple cultivation's spatial characteristics, and (3) assess the effects of pineapple expansion on surrounding forest ecosystems, on the agricultural matrix and on biodiversity conservation. Our results indicate that pineapple production concentrates land, labor, and financial resources, which has a homogenizing effect on the agricultural economy in the study region. This constrains farm-based livelihoods, with larger implications for food security and agricultural diversity. Landscape ecology analyses further reveal how pineapple production simplifies and homogenizes the agricultural matrix between forest patches, which is likely to have a negative effect on biodiversity. To offset the effects of pineapple expansion on social and environmental systems, we recommend developing landscape level land use planning capacity. Furthermore, agricultural and conservation policy reform is needed to promote landscape heterogeneity and economic diversity within the agricultural sector. Our interdisciplinary research provides a detailed examination of the social and ecological impacts of

  1. Capability of integrated MODIS imagery and ALOS for oil palm, rubber and forest areas mapping in tropical forest regions.

    Science.gov (United States)

    Razali, Sheriza Mohd; Marin, Arnaldo; Nuruddin, Ahmad Ainuddin; Shafri, Helmi Zulhaidi Mohd; Hamid, Hazandy Abdul

    2014-05-07

    Various classification methods have been applied for low resolution of the entire Earth's surface from recorded satellite images, but insufficient study has determined which method, for which satellite data, is economically viable for tropical forest land use mapping. This study employed Iterative Self Organizing Data Analysis Techniques (ISODATA) and K-Means classification techniques to classified Moderate Resolution Imaging Spectroradiometer (MODIS) Surface Reflectance satellite image into forests, oil palm groves, rubber plantations, mixed horticulture, mixed oil palm and rubber and mixed forest and rubber. Even though frequent cloud cover has been a challenge for mapping tropical forests, our MODIS land use classification map found that 2008 ISODATA-1 performed well with overall accuracy of 94%, with the highest Producer's Accuracy of Forest with 86%, and were consistent with MODIS Land Cover 2008 (MOD12Q1), respectively. The MODIS land use classification was able to distinguish young oil palm groves from open areas, rubber and mature oil palm plantations, on the Advanced Land Observing Satellite (ALOS) map, whereas rubber was more easily distinguished from an open area than from mixed rubber and forest. This study provides insight on the potential for integrating regional databases and temporal MODIS data, in order to map land use in tropical forest regions.

  2. Understanding and simulating the link between African easterly waves and Atlantic tropical cyclones using a regional climate model: the role of domain size and lateral boundary conditions

    Energy Technology Data Exchange (ETDEWEB)

    Caron, Louis-Philippe [MISU, Stockholm University, Stockholm (Sweden); Universite du Quebec a Montreal, CRCMD Network, Montreal, QC (Canada); Jones, Colin G. [Swedish Meterological and Hydrological Institute, Rossby Center, Norrkoeping (Sweden)

    2012-07-15

    Using a suite of lateral boundary conditions, we investigate the impact of domain size and boundary conditions on the Atlantic tropical cyclone and african easterly Wave activity simulated by a regional climate model. Irrespective of boundary conditions, simulations closest to observed climatology are obtained using a domain covering both the entire tropical Atlantic and northern African region. There is a clear degradation when the high-resolution model domain is diminished to cover only part of the African continent or only the tropical Atlantic. This is found to be the result of biases in the boundary data, which for the smaller domains, have a large impact on TC activity. In this series of simulations, the large-scale Atlantic atmospheric environment appears to be the primary control on simulated TC activity. Weaker wave activity is usually accompanied by a shift in cyclogenesis location, from the MDR to the subtropics. All ERA40-driven integrations manage to capture the observed interannual variability and to reproduce most of the upward trend in tropical cyclone activity observed during that period. When driven by low-resolution global climate model (GCM) integrations, the regional climate model captures interannual variability (albeit with lower correlation coefficients) only if tropical cyclones form in sufficient numbers in the main development region. However, all GCM-driven integrations fail to capture the upward trend in Atlantic tropical cyclone activity. In most integrations, variations in Atlantic tropical cyclone activity appear uncorrelated with variations in African easterly wave activity. (orig.)

  3. Diffusion of milk as a new food to tropical regions : the example of Indonesia, 1880- 1942

    NARCIS (Netherlands)

    Hartog, den A.P.

    1986-01-01

    The problem was analysed of why and how milk and milk products spread from industrialized countries with a dairying tradition to tropical countries with no such tradition. This interdisciplinary study uses the social sciences, nutritional sciences and social history in an approach to the diffusion

  4. Expanding the geography of evapotranspiration: An improved method to quantify land-to-air water fluxes in tropical and subtropical regions.

    Directory of Open Access Journals (Sweden)

    Daniela Jerszurki

    Full Text Available The development of new reference evapotranspiration (ETo methods hold significant promise for improving our quantitative understanding of climatic impacts on water loss from the land to the atmosphere. To address the challenge of estimating ETo in tropical and subtropical regions where direct measurements are scarce we tested a new method based on geographical patterns of extraterrestrial radiation (Ra and atmospheric water potential (Ψair. Our approach consisted of generating daily estimates of ETo across several climate zones in Brazil-as a model system-which we compared with standard EToPM (Penman-Monteith estimates. In contrast with EToPM, the simplified method (EToMJS relies solely on Ψair calculated from widely available air temperature (oC and relative humidity (% data, which combined with Ra data resulted in reliable estimates of equivalent evaporation (Ee and ETo. We used regression analyses of Ψair vs EToPM and Ee vs EToPM to calibrate the EToMJS(Ψair and EToMJS estimates from 2004 to 2014 and between seasons and climatic zone. Finally, we evaluated the performance of the new method based on the coefficient of determination (R2 and correlation (R, index of agreement "d", mean absolute error (MAE and mean reason (MR. This evaluation confirmed the suitability of the EToMJS method for application in tropical and subtropical regions, where the climatic information needed for the standard EToPM calculation is absent.

  5. Upscaling Empirically Based Conceptualisations to Model Tropical Dominant Hydrological Processes for Historical Land Use Change

    Science.gov (United States)

    Toohey, R.; Boll, J.; Brooks, E.; Jones, J.

    2009-12-01

    Surface runoff and percolation to ground water are two hydrological processes of concern to the Atlantic slope of Costa Rica because of their impacts on flooding and drinking water contamination. As per legislation, the Costa Rican Government funds land use management from the farm to the regional scale to improve or conserve hydrological ecosystem services. In this study, we examined how land use (e.g., forest, coffee, sugar cane, and pasture) affects hydrological response at the point, plot (1 m2), and the field scale (1-6ha) to empirically conceptualize the dominant hydrological processes in each land use. Using our field data, we upscaled these conceptual processes into a physically-based distributed hydrological model at the field, watershed (130 km2), and regional (1500 km2) scales. At the point and plot scales, the presence of macropores and large roots promoted greater vertical percolation and subsurface connectivity in the forest and coffee field sites. The lack of macropores and large roots, plus the addition of management artifacts (e.g., surface compaction and a plough layer), altered the dominant hydrological processes by increasing lateral flow and surface runoff in the pasture and sugar cane field sites. Macropores and topography were major influences on runoff generation at the field scale. Also at the field scale, antecedent moisture conditions suggest a threshold behavior as a temporal control on surface runoff generation. However, in this tropical climate with very intense rainstorms, annual surface runoff was less than 10% of annual precipitation at the field scale. Significant differences in soil and hydrological characteristics observed at the point and plot scales appear to have less significance when upscaled to the field scale. At the point and plot scales, percolation acted as the dominant hydrological process in this tropical environment. However, at the field scale for sugar cane and pasture sites, saturation-excess runoff increased as

  6. Tropical forests are a net carbon source based on aboveground measurements of gain and loss

    Science.gov (United States)

    Baccini, A.; Walker, W.; Carvalho, L.; Farina, M.; Sulla-Menashe, D.; Houghton, R. A.

    2017-10-01

    The carbon balance of tropical ecosystems remains uncertain, with top-down atmospheric studies suggesting an overall sink and bottom-up ecological approaches indicating a modest net source. Here we use 12 years (2003 to 2014) of MODIS pantropical satellite data to quantify net annual changes in the aboveground carbon density of tropical woody live vegetation, providing direct, measurement-based evidence that the world’s tropical forests are a net carbon source of 425.2 ± 92.0 teragrams of carbon per year (Tg C year-1). This net release of carbon consists of losses of 861.7 ± 80.2 Tg C year-1 and gains of 436.5 ± 31.0 Tg C year-1. Gains result from forest growth; losses result from deforestation and from reductions in carbon density within standing forests (degradation or disturbance), with the latter accounting for 68.9% of overall losses.

  7. REGIONAL GEOLGICAL MAPPING IN TROPICAL ENVIRONMENTS USING LANDSAT TM AND SRTM REMOTE SENSING DATA

    Directory of Open Access Journals (Sweden)

    A. Beiranvand Pour

    2015-10-01

    Full Text Available Landsat Thematic Mapper (TM and Shuttle Radar Topography Mission (SRTM data were used to produce geological maps in tropical environments. Lineament, lithology and landform maps were produced for all states in peninsular Malaysia in this study. Kedah, Perak and Terengganu states have been selected as case studies to demonstrate the results of the data and techniques used. Directional filtering technique was applied to Landsat TM bands 4, 5 and 3 for lineament mapping. The lithology map was produced using Landsat TM bands combination consist of bands 4, 3 and 2. Digital elevation model and landform map were produced using SRTM data in 3 Dimension (3D and 2 Dimension (2D perspective views, respectively. The produced geological maps and the remote sensing data and methods applied in this study are mostly appropriate for hazard risk mapping applications and mineral exploration projects in the peninsular Malaysia and tropical environments.

  8. Coupled social and ecological outcomes of agricultural intensification in Costa Rica and the future of biodiversity conservation in tropical agricultural regions

    Science.gov (United States)

    Sanfiorenzo, A. R.; Waits, L.; Finegan, B.; Shaver, I.; Chain Guadarrama, A.; Cleary, K.; Santiago-Garcia, R.; Hormel, L.; Vierling, L. A.; Bosque-Perez, N.; DeClerck, F.; Fagan, M. E.; Sibelet, N.

    2016-12-01

    Tropical ecosystem conversion to agriculture has caused widespread habitat loss and created fragmented landscapes composed of remnant forest patches embedded in a matrix of agricultural land uses. Non-traditional agricultural export (NTAE) crops such as pineapple are rapidly replacing multiuse landscapes characterized by a diverse matrix of pasture and smallholder crops with intensive, large-scale, monoculture plantations. Using an interdisciplinary approach, we examine the coupled social and ecological implications of agricultural intensification Guided by frameworks from political economy, landscape ecology and landscape genetics we: (1) describe the social and economic implications of pineapple expansion, specifically the concentration of land, labor and financial resources, (2) quantify pineapple cultivation's spatial characteristics, and (3) assess the effects of pineapple expansion on surrounding forest ecosystems, on the agricultural matrix and on biodiversity conservation. Our results indicate that pineapple production concentrates land, labor, and financial resources, which has a homogenizing effect on the agricultural economy in the study region. This constrains farm-based livelihoods, with larger implications for food security and agricultural diversity. Landscape ecology and genetics analyses further reveal how pineapple production simplifies and homogenizes the agricultural matrix between forest patches, which increase the genetic structure and reduce the genetic diversity of Symphonia globulifera a forest understory tree species. To offset the effects of agricultural intensification on social and environmental systems, we recommend developing landscape level land use planning capacity. Furthermore, agricultural and conservation policy reform is needed to promote landscape heterogeneity and economic diversity within the agricultural sector. Our interdisciplinary research provides a detailed examination of the social and ecological impacts of

  9. Test Operations Procedure (TOP) 01-1-020 Tropical Regions Environmental Considerations

    Science.gov (United States)

    2013-02-08

    to exude tannins , sugars, and other natural plant products, which may support microbial growth and corrosion processes. 2.2 Test Site Severity...Containers in Humid Environments, US Army Tropic Test Center, TECOM Project No. 7-C0-PB5-TT1-004, 1978. 16. A Technical Analysis to Identify Ideal...1973. 37. MIL-STD-810G, Test Method Standard, Environmental Engineering Considerations and Laboratory Tests, 2008. 38. A Technical Analysis

  10. Refined tropical curve counts and canonical bases for quantum cluster algebras

    DEFF Research Database (Denmark)

    Mandel, Travis

    We express the (quantizations of the) Gross-Hacking-Keel-Kontsevich canonical bases for cluster algebras in terms of certain (Block-Göttsche) weighted counts of tropical curves. In the process, we obtain via scattering diagram techniques a new invariance result for these Block-Göttsche counts....

  11. Potential use of a regional climate model in seasonal tropical cyclone activity predictions in the western North Pacific

    Energy Technology Data Exchange (ETDEWEB)

    Au-Yeung, Andie Y.M.; Chan, Johnny C.L. [City University of Hong Kong, Guy Carpenter Asia-Pacific Climate Impact Centre, School of Energy and Environment, Kowloon, Hong Kong (China)

    2012-08-15

    This study investigates the potential use of a regional climate model in forecasting seasonal tropical cyclone (TC) activity. A modified version of Regional Climate Model Version 3 (RegCM3) is used to examine the ability of the model to simulate TC genesis and landfalling TC tracks for the active TC season in the western North Pacific. In the model, a TC is identified as a vortex satisfying several conditions, including local maximum relative vorticity at 850 hPa with a value {>=}450 x 10{sup -6} s{sup -1}, and the temperature at 300 hPa being 1 C higher than the average temperature within 15 latitude radius from the TC center. Tracks are traced by following these found vortices. Six-month ensemble (8 members each) simulations are performed for each year from 1982 to 2001 so that the climatology of the model can be compared to the Joint Typhoon Warning Center (JTWC) observed best-track dataset. The 20-year ensemble experiments show that the RegCM3 can be used to simulate vortices with a wind structure and temperature profile similar to those of real TCs. The model also reproduces tracks very similar to those observed with features like genesis in the tropics, recurvature at higher latitudes and landfall/decay. The similarity of the 500-hPa geopotential height patterns between RegCM3 and the European Centre for Medium-Range Weather Forecasts 40 Year Re-analysis (ERA-40) shows that the model can simulate the subtropical high to a large extent. The simulated climatological monthly spatial distributions as well as the interannual variability of TC occurrence are also similar to the JTWC data. These results imply the possibility of producing seasonal forecasts of tropical cyclones using real-time global climate model predictions as boundary conditions for the RegCM3. (orig.)

  12. Propagation Measurement on Earth-Sky Signal Effects for High Speed Train Satellite Channel in Tropical Region at Ku-Band

    Directory of Open Access Journals (Sweden)

    Abdulmajeed H. J. Al-Jumaily

    2015-01-01

    Full Text Available Recent advances in satellite communication technologies in the tropical regions have led to significant increase in the demand for services and applications that require high channel quality for mobile satellite terminals. Determination and quantification of these requirements are important to optimize service quality, particularly in the Malaysian region. Moreover, the tests on current satellite propagation models were carried out at temperate regions whose environmental characteristics are much different from those in Malaysia. This difference renders these propagation models inapplicable and irrelevant to tropical regions in general. This paper presents the link characteristics observations and performance analysis with propagation measurements done in tropical region to provide an accurate database regarding rain and power arches supply (PAs attenuations in the tropics for mobile scenarios. Hence, an extension for improving the performance assessment and analysis of satellite/transmission has been achieved. The Malaysia propagation measurement for mobile scenario (Malaysia-PMMS enables first-hand coarse estimation and attenuation analysis, because the attenuation resulting from rain and PAs becomes easily amenable for measurement. Parallel to that, the measured attenuation has been compared with that of the simulated output at noise floor level. The underlying analytical tool is validated by measurements specific at tropical region, for dynamic model of mobile satellite links operating at higher than 10 GHz.

  13. Vascular flora of Kenya, based on the Flora of Tropical East Africa

    Directory of Open Access Journals (Sweden)

    Yadong Zhou

    2017-11-01

    Full Text Available Kenya, an African country with major higher plant diversity, has a corresponding diversity of plant associations, because of the wide geographic distribution, diverse climatic conditions and soil types. In this article, all vascular plants of Kenya were counted based on the completed "Flora of Tropical East Africa (FTEA", and all families and genera were revised using recent molecular systematics research, forming a "Synoptic List of Families and Genera of Kenyan Vascular Plants (SLFGKVP". In total, there are 225 families, 1538 genera and 6293 indigenous species and and 62 families, 302 genera and 588 exotic species in Kenya. The Fabaceae with 98 genera and 576 Species is the largest family. Two of the seven plant distribution regions of Kenya, K4 and K7 are the most species-richest areas with regard to both total and endemic species, with 3375 and 3191 total species and 174 and 185 endemic species in K4 and K7 respectively. While, K3 and K5 have the highest density of both total and endemic species. K1 has the lowest density of total species, and K2 has the lowest density of endemic species.

  14. Mechanisms, timing and quantities of recharge to groundwater in semi-arid and tropical regions

    International Nuclear Information System (INIS)

    Edmunds, W.M.

    2001-01-01

    Groundwater being exploited in many and and semi-arid regions at the present day was recharged during former humid episodes of the Pleistocene or Holocene and, in contrast, the amounts derived from modem recharge are small generally small and variable. Geochemical and isotopic techniques provide the most effective way to calculate modem recharge and to investigate recharge history, since physically- based water-balance methods are generally inapplicable in semiarid regions. Examples from Africa (Senegal, Niger, Nigeria, Sudan as well as Cyprus) show that direct recharge rates may vary from zero to around 40% of mean rainfall, dependent primarily on the soil depth and the lithology. Spatial variability presents a real problem in any recharge investigation but results from Senegal show that unsaturated zone profiles may be extrapolated using the chemistry of shallow groundwater. Unsaturated-zone studies show that there are limiting conditions to direct recharge through soil, but that present day replenishment of aquifers takes place via wadis and channels. In the Butana area of central Sudan the regional groundwater was also recharged during a mid-Holocene wet phase and is now in decline. The only current recharge sources, which can be recognised distinctly using stable isotopes, are Nile baseflow and ephemeral wadi floods. (author)

  15. Trace element uptake by Eleocharis equisetina (spike rush) in an abandoned acid mine tailings pond, northeastern Australia: Implications for land and water reclamation in tropical regions

    International Nuclear Information System (INIS)

    Lottermoser, Bernd G.; Ashley, Paul M.

    2011-01-01

    This study was conducted to determine the uptake of trace elements by the emergent wetland plant species Eleocharis equisetina at the historic Jumna tin processing plant, tropical Australia. The perennial emergent sedge was found growing in acid waters (pH 2.45) and metal-rich tailings (SnAsCuPbZn). E. equisetina displayed a pronounced acid tolerance and tendency to exclude environmentally significant elements (Al, As, Cd, Ce, Co, Cu, Fe, La, Ni, Pb, Se, Th, U, Y, Zn) from its above-substrate biomass. This study demonstrates that geobotanical and biogeochemical examinations of wetland plants at abandoned mined lands of tropical areas can reveal pioneering, metal-excluding macrophytes. Such aquatic macrophytes are of potential use in the remediation of acid mine waters and sulfidic tailings and the reclamation of disturbed acid sulfate soils in subtropical and tropical regions. - Highlights: → In tropical Australia, Eleocharis equisetina grows in an acid mine tailings pond. → Eleocharis equisetina excludes environmentally significant elements from its biomass. → Inspections of equatorial mined lands can reveal metal-excluding aquatic macrophytes. → Such plants are of use in land and water remediation in tropical regions. - The metal-excluding aquatic macrophyte Eleocharis equisetina is of use in land and water remediation in tropical regions.

  16. Trace element uptake by Eleocharis equisetina (spike rush) in an abandoned acid mine tailings pond, northeastern Australia: Implications for land and water reclamation in tropical regions

    Energy Technology Data Exchange (ETDEWEB)

    Lottermoser, Bernd G., E-mail: Bernd.Lottermoser@utas.edu.au [School of Earth Sciences, University of Tasmania, Private Bag 79, Hobart, Tasmania 7001 (Australia); Ashley, Paul M. [Earth Sciences, University of New England, Armidale, New South Wales 2351 (Australia)

    2011-10-15

    This study was conducted to determine the uptake of trace elements by the emergent wetland plant species Eleocharis equisetina at the historic Jumna tin processing plant, tropical Australia. The perennial emergent sedge was found growing in acid waters (pH 2.45) and metal-rich tailings (SnAsCuPbZn). E. equisetina displayed a pronounced acid tolerance and tendency to exclude environmentally significant elements (Al, As, Cd, Ce, Co, Cu, Fe, La, Ni, Pb, Se, Th, U, Y, Zn) from its above-substrate biomass. This study demonstrates that geobotanical and biogeochemical examinations of wetland plants at abandoned mined lands of tropical areas can reveal pioneering, metal-excluding macrophytes. Such aquatic macrophytes are of potential use in the remediation of acid mine waters and sulfidic tailings and the reclamation of disturbed acid sulfate soils in subtropical and tropical regions. - Highlights: > In tropical Australia, Eleocharis equisetina grows in an acid mine tailings pond. > Eleocharis equisetina excludes environmentally significant elements from its biomass. > Inspections of equatorial mined lands can reveal metal-excluding aquatic macrophytes. > Such plants are of use in land and water remediation in tropical regions. - The metal-excluding aquatic macrophyte Eleocharis equisetina is of use in land and water remediation in tropical regions.

  17. IMPACT ASSESSMENT OF TROPICAL CYCLONE HUD HUD ON COASTAL REGION OF VISAKHAPATNAM, ANDHRA PRADESH, INDIA

    Directory of Open Access Journals (Sweden)

    G. Vivek

    2015-10-01

    Full Text Available Tropical cyclone is a rapidly rotating storm system characterized by a low pressure center, strong winds, and a spiral arrangements of thunderstorms that produce heavy rain. Tropical cyclones typically form over large bodies of relatively warm water. On 6th October 2014 Hud Hud originates from a low pressure system that formed under the influence of an upper air cyclonic circulation in the Andaman Sea. On 9th October 2014 the IMD department classified the Hud Hud as a very severe cyclonic storm on IMD scale and category 4 on Staffir-Simpson scale. The cyclone hit the coast of Visakhapatnam on 12th October 2014 at wind speed of 175 km/h which caused extensive damage to the city and the neighbouring districts. The damage caused by Cyclone Hud Hud not only changed the landscape of the port city, but also made it the first city in the country to be directly hit by a cyclone since 1891 as per the records of the IMD. The remote sensing technique used here is NDVI. NDVI will separate vegetation and non-vegetation part. The NDVI will be classified in ERDAS and calculated the area using ARCGIS. The satellite data of 4th October 2014 show s before the cyclone, 14th October 2014 shows after the cyclone and 7th December 2014 after two month of cyclone.

  18. Tropical Freshwater Biology

    African Journals Online (AJOL)

    Tropical Freshwater Biology promotes the publication of scientific contributions in the field of freshwater biology in the tropical and subtropical regions of the world. One issue is published annually but this number may be increased. Original research papers and short communications on any aspect of tropical freshwater ...

  19. The effects of the insecticide lambda-Cyhalothrin on the earthworm Eisenia fetida under experimental conditions of tropical and temperate regions

    International Nuclear Information System (INIS)

    Garcia, Marcos; Scheffczyk, Adam; Garcia, Terezinha; Roembke, Joerg

    2011-01-01

    Plant Protection Products can affect soil organisms and thus might have negative impacts on soil functions. Little research has been performed on their impact on tropical soils. Therefore, the effects of the insecticide lambda-Cyhalothrin on earthworms were evaluated in acute and chronic laboratory tests modified for tropical conditions, i.e. at selected temperatures (20 and 28 o C) and with two strains (temperate and tropical) of the compost worm Eisenia fetida. The insecticide was spiked in two natural soils, in OECD artificial soil and a newly developed tropical artificial soil. The effects of lambda-Cyhalothrin did rarely vary in the same soil at tropical (LC50: 68.5-229 mg a.i./kg dry weight (DW); EC50: 54.2-60.2 mg a.i./kg DW) and temperate (LC50: 99.8-140 mg a.i./kg DW; EC50: 37.4-44.5 mg a.i./kg DW) temperatures. In tests with tropical soils and high temperature, effect values differed by up to a factor of ten. - Research highlights: → In one soil, effects of lambda-Cyhalothrin did not vary much at two temperatures. → In tropical soils at high temperature, effects differed by up to a factor of ten. → In the tropics, effects of pesticides can be higher or lower as in temperate regions. - The effects of the insecticide lambda-cyhalothrin on earthworms did not differ considerably when performed in the same soil under different temperatures, but LC/EC 50 values varied by a factor of ten between OECD and tropical artificial soil.

  20. The effects of the insecticide lambda-Cyhalothrin on the earthworm Eisenia fetida under experimental conditions of tropical and temperate regions

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Marcos [Embrapa Amazonia Ocidental, Rod. AM-10, Km 28, 69.011-970 Manaus, AM (Brazil); Scheffczyk, Adam [ECT Oekotoxikologie, Boettgerstr. 2-14, D-65439 Floersheim (Germany); Garcia, Terezinha [Embrapa Amazonia Ocidental, Rod. AM-10, Km 28, 69.011-970 Manaus, AM (Brazil); Roembke, Joerg, E-mail: j-roembke@ect.d [ECT Oekotoxikologie, Boettgerstr. 2-14, D-65439 Floersheim (Germany)

    2011-02-15

    Plant Protection Products can affect soil organisms and thus might have negative impacts on soil functions. Little research has been performed on their impact on tropical soils. Therefore, the effects of the insecticide lambda-Cyhalothrin on earthworms were evaluated in acute and chronic laboratory tests modified for tropical conditions, i.e. at selected temperatures (20 and 28 {sup o}C) and with two strains (temperate and tropical) of the compost worm Eisenia fetida. The insecticide was spiked in two natural soils, in OECD artificial soil and a newly developed tropical artificial soil. The effects of lambda-Cyhalothrin did rarely vary in the same soil at tropical (LC50: 68.5-229 mg a.i./kg dry weight (DW); EC50: 54.2-60.2 mg a.i./kg DW) and temperate (LC50: 99.8-140 mg a.i./kg DW; EC50: 37.4-44.5 mg a.i./kg DW) temperatures. In tests with tropical soils and high temperature, effect values differed by up to a factor of ten. - Research highlights: In one soil, effects of lambda-Cyhalothrin did not vary much at two temperatures. In tropical soils at high temperature, effects differed by up to a factor of ten. In the tropics, effects of pesticides can be higher or lower as in temperate regions. - The effects of the insecticide lambda-cyhalothrin on earthworms did not differ considerably when performed in the same soil under different temperatures, but LC/EC{sub 50} values varied by a factor of ten between OECD and tropical artificial soil.

  1. Tropical Soil Chemistry

    DEFF Research Database (Denmark)

    Borggaard, Ole K.

    and environmental protection. Tropical Soil Chemistry by Ole K. Borggaard provides an overview of the composition, occurrence, properties, processes, formation, and environmental vulnerability of various tropical soil types (using American Soil Taxonomy for classification). The processes and the external factors...... soil chemical issues are also presented to assess when, why, and how tropical soils differ from soils in other regions. This knowledge can help agricultural specialists in the tropics establish sustainable crop production. Readers are assumed to be familiar with basic chemistry, physics...

  2. Regional modelling of tracer transport by tropical convection – Part 2: Sensitivity to model resolutions

    Directory of Open Access Journals (Sweden)

    J. Arteta

    2009-09-01

    Full Text Available The general objective of this series of two papers is to evaluate long duration limited-area simulations with idealised tracers as a possible tool to assess the tracer transport in chemistry-transport models (CTMs. In this second paper we analyse the results of three simulations using different horizontal and vertical resolutions. The goal is to study the impact of the model spatial resolution on convective transport of idealized tracer in the tropics. The reference simulation (REF uses a 60 km horizontal resolution and 300 m vertically in the upper troposphere/lower stratosphere (UTLS. A 20 km horizontal resolution simulation (HR is run as well as a simulation with 850 m vertical resolution in the UTLS (CVR. The simulations are run for one month during the SCOUT-O3 field campaign. Aircraft data, TRMM rainrate estimates and radiosoundings have been used to evaluate the simulations. They show that the HR configuration gives generally a better agreement with the measurements than the REF simulation. The CVR simulation gives generally the worst results. The vertical distribution of the tropospheric tracers for the simulations has a similar shape with a ~15 km altitude maximum for the 6h-lifetime tracer of 0.4 ppbv for REF, 1.2 for HR and 0.04 for CVR. These differences are related to the dynamics produced by the three simulations that leads to larger values of the upward velocities on average for HR and lower for CVR compared to REF. HR simulates more frequent and stronger convection leading to enhanced fluxes compared to REF and higher detrainment levels compared to CVR. HR provides also occasional overshoots over the cold point dynamical barrier. For the stratospheric tracers the differences between the three simulations are small. The diurnal cycle of the fluxes of all tracers in the Tropical Tropopause Layer exhibits a maximum linked to the maximum of convective activity.

  3. Deglaciation in the tropical Indian Ocean driven by interplay between the regional monsoon and global teleconnections

    Digital Repository Service at National Institute of Oceanography (India)

    Saraswat, R.; Lea, D.W.; Nigam, R.; Mackensen, A.; Naik, Dinesh K.

    High resolution climate records of the ice age terminations from monsoon-dominated regions reveal the interplay of regional and global driving forces. Speleothem records from Chinese caves indicate that glacial terminations were interrupted...

  4. Assessing the extent of "conflict of use" in multipurpose tropical forest trees: a regional view.

    Science.gov (United States)

    Herrero-Jáuregui, Cristina; Guariguata, Manuel R; Cárdenas, Dairon; Vilanova, Emilio; Robles, Marco; Licona, Juan Carlos; Nalvarte, Walter

    2013-11-30

    In the context of multiple forest management, multipurpose tree species which provide both timber and non-timber forest products (NTFP), present particular challenges as the potential of conflicting use for either product may be high. One key aspect is that the magnitude of conflict of use can be location specific, thus adding complexity to policy development. This paper focuses on the extent to which the potential for conflict of use in multipurpose tree species varies across the Amazonian lowland forests shared by Peru, Bolivia, Colombia, Ecuador and Venezuela, emphasizing the economic dimension of conflict. Based on a review of the current normative and regulatory aspects of timber and NTFP extraction in the five countries, the paper also briefly discusses the opportunities and constraints for harmonization of timber and NTFP management of multipurpose species across the region. It was found that about half of the 336 timber species reviewed across the five countries also have non-timber uses. Eleven timber species are multipurpose in all five countries: Calophyllum brasiliense, Cedrela odorata, Ceiba pentandra, Clarisia racemosa, Ficus insipida, Jacaranda copaia, Schefflera morototoni, Simarouba amara and Terminalia amazonia. Seven other multipurpose species occurred only in either Venezuela (Tabebuia impetiginosa, Spondias mombin, Pentaclethra macroloba, Copaifera officinalis, Chlorophora tinctoria, Carapa guianensis) or Ecuador (Tabebuia chrysantha). Four multipurpose tree species presented the highest potential of conflict of use across the region: Dipteryx odorata, Tabebuia serratifolia, Hymenaea courbaril and Myroxylon balsamum yet these were not evenly distributed across all five countries. None of the five studied countries have specific legislation to promote sustainable use of any of the multipurpose species reported here and thus mitigate potential conflict of use; nor documented management options for integration or else segregation of both their

  5. Elimination of neglected tropical diseases in the South-East Asia Region of the World Health Organization.

    Science.gov (United States)

    Narain, Jai P; Dash, A P; Parnell, B; Bhattacharya, S K; Barua, S; Bhatia, R; Savioli, L

    2010-03-01

    The neglected tropical diseases (NTDs), which affect the very poor, pose a major public health problem in the South-East Asia Region of the World Health Organization (WHO). Although more than a dozen NTDs affect the region, over the past five years four of them in particular - leprosy, lymphatic filariasis, visceral leishmaniasis (kala-azar) and yaws - have been targeted for elimination. These four were selected for a number of reasons. First, they affect the WHO South-East Asia Region disproportionately. For example, every year around 67% of all new leprosy cases and 60% of all new cases of visceral leishmaniasis worldwide occur in countries of the region, where as many as 850 million inhabitants are at risk of contracting lymphatic filariasis. In addition, several epidemiological, technological and historical factors that are unique to the region make each of these four diseases amenable to elimination. Safe and effective tools and interventions to achieve these targets are available and concerted efforts to scale them up, singly or in an integrated manner, are likely to lead to success. The World Health Assembly and the WHO Regional Committee, through a series of resolutions, have already expressed regional and global commitments for the elimination of these diseases as public health problems. Such action is expected to have a quick and dramatic impact on poverty reduction and to contribute to the achievement of the Millennium Development Goals. This paper reviews the policy rationale for disease control in the WHO South-East Asia Region, the progress made so far, the lessons learnt along the way, and the remaining challenges and opportunities.

  6. Challenges and opportunities for improving eco-efficiency of tropical forage-based systems to mitigate greenhouse gas emissions

    Directory of Open Access Journals (Sweden)

    Michael Peters

    2013-12-01

    Full Text Available Forage-based livestock production plays a key role in national and regional economies, for food security and poverty alleviation, but is considered a major contributor to agricultural GHG emissions. While demand for livestock products is predicted to increase, there is political and societal pressure both to reduce environmental impacts and to convert some of the pasture area to alternative uses, such as crop production and environmental conservation. Thus, it is essential to develop approaches for sustainable intensification of livestock systems to mitigate GHG emissions, addressing biophysical, socio-economic and policy challenges. This paper highlights the potential of improved tropical forages, linked with policy incentives, to enhance livestock production, while reducing its environmental footprint. Emphasis is on crop-livestock systems. We give examples for sustainable intensification to mitigate GHG emissions, based on improved forages in Brazil and Colombia, and suggest future perspectives.

  7. Climacteric complaints among very low-income women from a tropical region of Brazil

    Directory of Open Access Journals (Sweden)

    Sebastião Freitas de Medeiros

    Full Text Available CONTEXT AND OBJECTIVE: Climacteric symptoms may vary between different countries and cultures. Socioeconomic factors and climate may be implicated. The aim of this study was to identify climacteric symptomatology among very low-income Brazilian women, living in a hot and humid region. DESIGN AND SETTING: This cross-sectional population-based study was conducted in Cuiabá, at Júlio Müller University Hospital, a tertiary institution. METHODS: The study enrolled 354 climacteric women. The variables analyzed were social class, symptomatology and abnormal concurrent conditions. The study was approved by the hospital's research ethics committee. RESULTS: Sixty-five percent of the participants (232/354 were very poor and had had little schooling. The number of symptoms per woman was 8.0 ± 5.7. Hot flushes, nervousness, forgetfulness and fatigue were each found in nearly 60.0%. Tearfulness, depression, melancholy and insomnia were also frequent. Sexual problems were reported by 25%. The most relevant concurrent abnormal conditions reported were hypertension (33.9%, obesity (26.5%, arthritis/arthrosis (15.0% and diabetes mellitus (9.6%. Hot flushes were associated with tearfulness, nervousness and forgetfulness. CONCLUSION: Brazilian climacteric women of low income and low schooling present multiple symptoms. Vasomotor and psychosexual symptoms were the most prevalent disorders. Hot flushes were associated with nervousness, forgetfulness and tearfulness.

  8. An eddy-permitting, dynamically consistent adjoint-based assimilation system for the tropical Pacific: Hindcast experiments in 2000

    KAUST Repository

    Hoteit, Ibrahim; Cornuelle, B.; Heimbach, P.

    2010-01-01

    An eddy-permitting adjoint-based assimilation system has been implemented to estimate the state of the tropical Pacific Ocean. The system uses the Massachusetts Institute of Technology's general circulation model and its adjoint. The adjoint method

  9. Polynomial Chaos–Based Bayesian Inference of K-Profile Parameterization in a General Circulation Model of the Tropical Pacific

    KAUST Repository

    Sraj, Ihab; Zedler, Sarah E.; Knio, Omar; Jackson, Charles S.; Hoteit, Ibrahim

    2016-01-01

    The authors present a polynomial chaos (PC)-based Bayesian inference method for quantifying the uncertainties of the K-profile parameterization (KPP) within the MIT general circulation model (MITgcm) of the tropical Pacific. The inference

  10. Almendravirus: A Proposed New Genus of Rhabdoviruses Isolated from Mosquitoes in Tropical Regions of the Americas.

    Science.gov (United States)

    Contreras, Maria Angelica; Eastwood, Gillian; Guzman, Hilda; Popov, Vsevolod; Savit, Chelsea; Uribe, Sandra; Kramer, Laura D; Wood, Thomas G; Widen, Steven G; Fish, Durland; Tesh, Robert B; Vasilakis, Nikos; Walker, Peter J

    2017-01-11

    The Rhabdoviridae is a diverse family of negative-sense single-stranded RNA viruses, many of which infect vertebrate hosts and are transmitted by hematophagous arthropods. Others appear to be arthropod specific, circulating only within arthropod populations. Herein, we report the isolation and characterization of three novel viruses from mosquitoes collected from the Americas. Coot Bay virus was isolated from Anopheles quadrimaculatus mosquitoes collected in the Everglades National Park, Florida; Rio Chico virus was isolated from Anopheles triannulatus mosquitoes collected in Panama; and Balsa virus was isolated from two pools of Culex erraticus mosquitoes collected in Colombia. Sequence analysis indicated that the viruses share a similar genome organization to Arboretum virus and Puerto Almendras virus that had previously been isolated from mosquitoes collected in Peru. Each genome features the five canonical rhabdovirus structural protein genes as well as a gene encoding a class 1A viroporin-like protein (U1) located between the G and L genes (3'-N-P-M-G-U1-L-5'). Phylogenetic analysis of complete L protein sequences indicated that all five viruses cluster in a unique clade that is relatively deeply rooted in the ancestry of animal rhabdoviruses. The failure of all viruses in this clade to grow in newborn mice or vertebrate cells in culture suggests that they may be poorly adapted to replication in vertebrates. © The American Society of Tropical Medicine and Hygiene.

  11. Physically-based Assessment of Tropical Cyclone Damage and Economic Losses

    Science.gov (United States)

    Lin, N.

    2012-12-01

    Estimating damage and economic losses caused by tropical cyclones (TC) is a topic of considerable research interest in many scientific fields, including meteorology, structural and coastal engineering, and actuarial sciences. One approach is based on the empirical relationship between TC characteristics and loss data. Another is to model the physical mechanism of TC-induced damage. In this talk we discuss about the physically-based approach to predict TC damage and losses due to extreme wind and storm surge. We first present an integrated vulnerability model, which, for the first time, explicitly models the essential mechanisms causing wind damage to residential areas during storm passage, including windborne-debris impact and the pressure-debris interaction that may lead, in a chain reaction, to structural failures (Lin and Vanmarcke 2010; Lin et al. 2010a). This model can be used to predict the economic losses in a residential neighborhood (with hundreds of buildings) during a specific TC (Yau et al. 2011) or applied jointly with a TC risk model (e.g., Emanuel et al 2008) to estimate the expected losses over long time periods. Then we present a TC storm surge risk model that has been applied to New York City (Lin et al. 2010b; Lin et al. 2012; Aerts et al. 2012), Miami-Dade County, Florida (Klima et al. 2011), Galveston, Texas (Lickley, 2012), and other coastal areas around the world (e.g., Tampa, Florida; Persian Gulf; Darwin, Australia; Shanghai, China). These physically-based models are applicable to various coastal areas and have the capability to account for the change of the climate and coastal exposure over time. We also point out that, although made computationally efficient for risk assessment, these models are not suitable for regional or global analysis, which has been a focus of the empirically-based economic analysis (e.g., Hsiang and Narita 2012). A future research direction is to simplify the physically-based models, possibly through

  12. Assessing the hydrological impacts of Tropical Cyclones on the Carolinas: An observational and modeling based investigation

    Science.gov (United States)

    Leeper, R. D.; Prat, O. P.; Blanton, B. O.

    2012-12-01

    During the warm season, the Carolinas are particularly prone to tropical cyclone (TC) activity and can be impacted in many different ways depending on storm track. The coasts of the Carolinas are the most vulnerable areas, but particular situations (Frances and Ivan 2004) affected communities far from the coasts (Prat and Nelson 2012). Regardless of where landfall occurs, TCs are often associated with intense precipitation and strong winds triggering a variety of natural hazards (storm surge, flooding, landslides). The assessment of societal and environmental impacts of TCs requires a suite of observations. The scarcity of station coverage, sensor limitations, and rainfall retrieval uncertainties are issues limiting the ability to assess accurately the impact of extreme precipitation events. Therefore, numerical models, such as the Weather Research and Forecasting model (WRF), can be valuable tools to investigate those impacts at regional and local scales and bridge the gap between observations. The goal of this study is to investigate the impact of TCs across the Carolinas using both observational and modeling technologies, and explore the usefulness of numerical methods in data-scarce regions. To fully assess TC impacts on the Carolinas inhabitants, storms impacting both coastal and inner communities will be selected and high-resolution WRF ensemble simulations generated from a suite of physic schemes for each TC to investigate their impact at finer scales. The ensemble member performance will be evaluated with respect to ground-based and satellite observations. Furthermore, results from the high-resolution WRF simulations, including the average wind-speed and the sea level pressure, will be used with the ADCIRC storm-surge and wave-model (Westerink et al, 2008) to simulate storm surge and waves along the Carolinas coast for TCs travelling along the coast or making landfall. This work aims to provide an assessment of the various types of impacts TCs can have

  13. Potential regulation on the climatic effect of Tibetan Plateau heating by tropical air-sea coupling in regional models

    Science.gov (United States)

    Wang, Ziqian; Duan, Anmin; Yang, Song

    2018-05-01

    Based on the conventional weather research and forecasting (WRF) model and the air-sea coupled mode WRF-OMLM, we investigate the potential regulation on the climatic effect of Tibetan Plateau (TP) heating by the air-sea coupling over the tropical Indian Ocean and western Pacific. Results indicate that the TP heating significantly enhances the southwesterly monsoon circulation over the northern Indian Ocean and the South Asia subcontinent. The intensified southwesterly wind cools the sea surface mainly through the wind-evaporation-SST (sea surface temperature) feedback. Cold SST anomaly then weakens monsoon convective activity, especially that over the Bay of Bengal, and less water vapor is thus transported into the TP along its southern slope from the tropical oceans. As a result, summer precipitation decreases over the TP, which further weakens the TP local heat source. Finally, the changed TP heating continues to influence the summer monsoon precipitation and atmospheric circulation. To a certain extent, the air-sea coupling over the adjacent oceans may weaken the effect of TP heating on the mean climate in summer. It is also implied that considerations of air-sea interaction are necessary in future simulation studies of the TP heating effect.

  14. A Phylogenetic and Phenotypic Analysis of Salmonella enterica Serovar Weltevreden, an Emerging Agent of Diarrheal Disease in Tropical Regions.

    Directory of Open Access Journals (Sweden)

    Carine Makendi

    2016-02-01

    Full Text Available Salmonella enterica serovar Weltevreden (S. Weltevreden is an emerging cause of diarrheal and invasive disease in humans residing in tropical regions. Despite the regional and international emergence of this Salmonella serovar, relatively little is known about its genetic diversity, genomics or virulence potential in model systems. Here we used whole genome sequencing and bioinformatics analyses to define the phylogenetic structure of a diverse global selection of S. Weltevreden. Phylogenetic analysis of more than 100 isolates demonstrated that the population of S. Weltevreden can be segregated into two main phylogenetic clusters, one associated predominantly with continental Southeast Asia and the other more internationally dispersed. Subcluster analysis suggested the local evolution of S. Weltevreden within specific geographical regions. Four of the isolates were sequenced using long read sequencing to produce high quality reference genomes. Phenotypic analysis in Hep-2 cells and in a murine infection model indicated that S. Weltevreden were significantly attenuated in these models compared to the classical S. Typhimurium reference strain SL1344. Our work outlines novel insights into this important emerging pathogen and provides a baseline understanding for future research studies.

  15. Tropical forests are a net carbon source based on aboveground measurements of gain and loss.

    Science.gov (United States)

    Baccini, A; Walker, W; Carvalho, L; Farina, M; Sulla-Menashe, D; Houghton, R A

    2017-10-13

    The carbon balance of tropical ecosystems remains uncertain, with top-down atmospheric studies suggesting an overall sink and bottom-up ecological approaches indicating a modest net source. Here we use 12 years (2003 to 2014) of MODIS pantropical satellite data to quantify net annual changes in the aboveground carbon density of tropical woody live vegetation, providing direct, measurement-based evidence that the world's tropical forests are a net carbon source of 425.2 ± 92.0 teragrams of carbon per year (Tg C year -1 ). This net release of carbon consists of losses of 861.7 ± 80.2 Tg C year -1 and gains of 436.5 ± 31.0 Tg C year -1 Gains result from forest growth; losses result from deforestation and from reductions in carbon density within standing forests (degradation or disturbance), with the latter accounting for 68.9% of overall losses. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  16. PV (photovoltaics) performance evaluation and simulation-based energy yield prediction for tropical buildings

    International Nuclear Information System (INIS)

    Saber, Esmail M.; Lee, Siew Eang; Manthapuri, Sumanth; Yi, Wang; Deb, Chirag

    2014-01-01

    Air pollution and climate change increased the importance of renewable energy resources like solar energy in the last decades. Rack-mounted PhotoVoltaics (PV) and Building Integrated PhotoVoltaics (BIPV) are the most common photovoltaic systems which convert incident solar radiation on façade or surrounding area to electricity. In this paper the performance of different solar cell types is evaluated for the tropical weather of Singapore. As a case study, on-site measured data of PV systems implemented in a zero energy building in Singapore, is analyzed. Different types of PV systems (silicon wafer and thin film) have been installed on rooftop, façade, car park shelter, railing and etc. The impact of different solar cell generations, arrays environmental conditions (no shading, dappled shading, full shading), orientation (South, North, East or West facing) and inclination (between PV module and horizontal direction) is investigated on performance of modules. In the second stage of research, the whole PV systems in the case study are simulated in EnergyPlus energy simulation software with several PV performance models including Simple, Equivalent one-diode and Sandia. The predicted results by different models are compared with measured data and the validated model is used to provide simulation-based energy yield predictions for wide ranges of scenarios. It has been concluded that orientation of low-slope rooftop PV has negligible impact on annual energy yield but in case of PV external sunshade, east façade and panel slope of 30–40° are the most suitable location and inclination. - Highlights: • Characteristics of PV systems in tropics are analyzed in depth. • The ambiguity toward amorphous panel energy yield in tropics is discussed. • Equivalent-one diode and Sandia models can fairly predict the energy yield. • A general guideline is provided to estimate the energy yield of PV systems in tropics

  17. Net Primary Productivity and Edaphic Fertility in Two Pluvial Tropical Forests in the Chocó Biogeographical Region of Colombia.

    Science.gov (United States)

    Quinto-Mosquera, Harley; Moreno, Flavio

    2017-01-01

    The net primary productivity (NPP) of tropical forests is a key process of the carbon cycle and therefore for the mitigation of global climate change. It has been proposed that NPP is limited by the availability of soil nutrients in lowland tropical forests and that belowground NPP decreases as edaphic fertility increases. This hypothesis was evaluated in two localities (Opogodó and Pacurita) of the Chocó Biogeographical region, one of the rainiest of the world, where the aboveground (litter and wood) and belowground (fine and coarse roots) components of NPP were measured. Fertility parameters (pH, nutrients, and texture) were also determined and related to NPP. Total NPP was similar between locations (23.7 vs. 24.2 t ha-1 year-1 for Opogodó and Pacurita, respectively). However, components of NPP showed differences: in Pacurita, with steeper topography, NPP of wood and coarse roots were higher; therefore, differences of topography and drainage between localities probably affected the NPP of wood. On the other hand, soils of Opogodó, where NPP of fine roots was higher, showed higher contents of sand, N+, and organic matter (OM). With the increase of pH, OM, N+, K, Mg, and sand, the NPP of leaves and fine roots as well as the percentage of NPP belowground also increased, which suggests NPP limitation by multiple nutrients. The increase of NPP belowground with the availability of edaphic nutrients evidenced a redistribution of the aboveground and belowground components of NPP with the increase of soil fertility in oligotrophic systems, probably as a mechanism to improve the capture of resources.

  18. Biofuels from Jatropha curcas oil – Perspectives for tropical regions

    Directory of Open Access Journals (Sweden)

    Becker Klaus

    2009-07-01

    Full Text Available Almost 40% of the world’s population of 6,7 billion people do not have access to affordable energy resources and drinking water of acceptable quality. But nothing is more important than the alleviation of hunger. The number of hungry people, according to the newest FAO statistics, has risen to close to one billion in 2008. Therefore, special attention needs to be given to research in food and agriculture. To this stock of global problems new challenges are added through the increase in human population of 80 million persons a year and the concomitant loss of large areas of former fertile agricultural land, mostly in the poorest countries. Jatropha curcas is the most primitive member of the large genus Euphorbiaceae. The name is derived from the Greek iatros (doctor and trophe (food. Jatropha curcas is a perennial plant, native and widely spread throughout the tropics. It is not grazed by animals, grows readily on degraded lands, is drought and to some extent disease resistant. It is a multipurpose plant. There are two genotypes of Jatropha curcas, a toxic and a non-toxic one. The latter genotype is found in Mexico only. Well developed dry seeds from Jatropha curcas weigh between 650- 750 mg and contain 30-35% of oil that is suitable for conversion into biodiesel of high quality by the conventional, proven processes. The kernel forms around 65% of the seeds. The de-oiled kernel meal has a crude protein content of between 58% and 60% and a favourable amino acid profile. Extracts of the toxic genotype provide chemicals with potential in medicinal, pharmaceutical and bio-pesticide application. In contrast to other fossil fuel alternatives, like biofuels from food crops such as maize, soybean, sugar cane and palm, bioenergy from Jatropha curcas grown on wasteland incurs no carbon debt and thus, offers immediate and sustained greenhouse gas advantages. Potential benefits of large scale Jatropha plantations on degraded land are expected to be

  19. Neglected tropical diseases: prevalence and risk factors for schistosomiasis and soil-transmitted helminthiasis in a region of Minas Gerais State, Brazil.

    Science.gov (United States)

    Couto, Luzivalda D; Tibiriça, Sandra H C; Pinheiro, Izabella O; Mitterofhe, Adalberto; Lima, Adilson C; Castro, Milton F; Gonçalves, Murilo; Silva, Marcio R; Guimarães, Ricardo J P S; Rosa, Florence M; Coimbra, Elaine S

    2014-06-01

    Among the neglected tropical diseases (NTDs), schistosomiasis and the three main soil-transmitted helminthiases (STHs), i.e., ascariasis, trichuriasis and hookworm infection, represent the most common infections in developing countries. In Brazil, there is a lack of epidemiological data in many parts of the country, which favors the unawareness of the real situation concerning these diseases. Due to this, we investigated the occurrence of schistosomiasis and STHs in a region of Minas Gerais State, Brazil. One stool sample was collected from 503 individuals, whose ages ranged from 0.1 to 91.2 years, and screened using both the Kato-Katz and the Formol-Ether methods. In parallel, a malacological survey was carried out in the main water bodies of the district, and Biomphalaria susceptibility assays and kernel-based techniques were also performed. No individual was found infected with Ascaris lumbricoides or hookworm. Schistosoma mansoni was the most common parasite found (1.6%). The prevalence was higher in males and the chance of acquiring the disease increased by 43.35 times with contact with a body of water. None of the Biomphalaria tenagophila and B. glabrata specimens were found naturally infected, but B. glabrata was highly susceptible to infection with Schistosoma mansoni. Using kernel-based techniques, clusters of Biomphalaria were found near the households where the infected individuals lived. Schistosomiasis was the most prevalent parasitic infection found. Our findings show that the occurrence of this disease has been underestimated by the local health care service, and highlight the importance of epidemiological surveillance in areas of low prevalence for schistosomiasis. © The Author 2014. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. Changes in intense tropical cyclone activity for the western North Pacific during the last decades derived from a regional climate model simulation

    Science.gov (United States)

    Barcikowska, Monika; Feser, Frauke; Zhang, Wei; Mei, Wei

    2017-11-01

    An atmospheric regional climate model (CCLM) was employed to dynamically downscale atmospheric reanalyses (NCEP/NCAR 1, ERA 40) over the western North Pacific and South East Asia. This approach is used for the first time to reconstruct a tropical cyclone climatology, which extends beyond the satellite era and serves as an alternative data set for inhomogeneous observation-derived records (Best Track Data sets). The simulated TC climatology skillfully reproduces observations of the recent decades (1978-2010), including spatial patterns, frequency, lifetime, trends, variability on interannual and decadal time scales and their association with the large-scale circulation patterns. These skills, facilitated here with the spectral nudging method, seem to be a prerequisite to understand the factors determining spatio-temporal variability of TC activity over the western North Pacific. Long-term trends (1948-2011 and 1959-2001) in both simulations show a strong increase of intense tropical cyclone activity. This contrasts with pronounced multidecadal variations found in observations. The discrepancy may partly originate from temporal inhomogeneities in atmospheric reanalyses and Best Track Data, which affect both the model-based and observational-based trends. An adjustment, which removes the simulated upward trend, reduces the apparent discrepancy. Ultimately, our observational and modeling analysis suggests an important contribution of multi-decadal fluctuations in the TC activity during the last six decades. Nevertheless, due to the uncertainties associated with the inconsistencies and quality changes of those data sets, we call for special caution when reconstructing long-term TC statistics either from atmospheric reanalyses or Best Track Data.

  1. Analysis of the interannual variability of tropical cyclones striking the California coast based on statistical downscaling

    Science.gov (United States)

    Mendez, F. J.; Rueda, A.; Barnard, P.; Mori, N.; Nakajo, S.; Espejo, A.; del Jesus, M.; Diez Sierra, J.; Cofino, A. S.; Camus, P.

    2016-02-01

    Hurricanes hitting California have a very low ocurrence probability due to typically cool ocean temperature and westward tracks. However, damages associated to these improbable events would be dramatic in Southern California and understanding the oceanographic and atmospheric drivers is of paramount importance for coastal risk management for present and future climates. A statistical analysis of the historical events is very difficult due to the limited resolution of atmospheric and oceanographic forcing data available. In this work, we propose a combination of: (a) statistical downscaling methods (Espejo et al, 2015); and (b) a synthetic stochastic tropical cyclone (TC) model (Nakajo et al, 2014). To build the statistical downscaling model, Y=f(X), we apply a combination of principal component analysis and the k-means classification algorithm to find representative patterns from a potential TC index derived from large-scale SST fields in Eastern Central Pacific (predictor X) and the associated tropical cyclone ocurrence (predictand Y). SST data comes from NOAA Extended Reconstructed SST V3b providing information from 1854 to 2013 on a 2.0 degree x 2.0 degree global grid. As data for the historical occurrence and paths of tropical cycloneas are scarce, we apply a stochastic TC model which is based on a Monte Carlo simulation of the joint distribution of track, minimum sea level pressure and translation speed of the historical events in the Eastern Central Pacific Ocean. Results will show the ability of the approach to explain seasonal-to-interannual variability of the predictor X, which is clearly related to El Niño Southern Oscillation. References Espejo, A., Méndez, F.J., Diez, J., Medina, R., Al-Yahyai, S. (2015) Seasonal probabilistic forecasting of tropical cyclone activity in the North Indian Ocean, Journal of Flood Risk Management, DOI: 10.1111/jfr3.12197 Nakajo, S., N. Mori, T. Yasuda, and H. Mase (2014) Global Stochastic Tropical Cyclone Model Based on

  2. Perturbations to the Lower Ionosphere by Tropical Cyclone Evan in the South Pacific Region

    DEFF Research Database (Denmark)

    Kumar, Sushil; Amor, Samir Nait; Chanrion, Olivier

    2017-01-01

    of the reflecting boundary of the lower ionosphere which is located in the mesosphere and lower thermosphere, and their analysis is, therefore, a way to study processes in these remote regions. Here we present a study on amplitude perturbations of local origin on the VLF transmitter signals (NPM, NLK, NAA and JJI...

  3. Exposure-plant response of ambient ozone over the tropical Indian region

    Directory of Open Access Journals (Sweden)

    S. Deb Roy

    2009-07-01

    Full Text Available A high resolution regional chemistry-transport model has been used to study the distribution of exposure-plant response index (AOT40, Accumulated exposure Over a Threshold of 40 ppb, expressed as ppb h over the Indian geographical region for the year 2003 as case study. The directives on ozone pollution in ambient air provided by United Nations Economic Commission for Europe (UNECE and World Health Organization (WHO for vegetation protection (AOT40 have been used to assess the air quality. A substantial temporal and spatial variation in AOT40 values has been observed across the Indian region. Large areas of India show ozone values above the AOT40 threshold limit (3000 ppb h for 3 months. Simulated AOT40 values are found to be substantially higher throughout the year over the most fertile Indo-Gangetic plains than the other regions of India, which can have an adverse effect on plants and vegetation in this region. The observed monthly AOT40 values reported from an Indian station, agree reasonably well with model simulated results. There is an underestimation of AOT40 in the model results during the periods of highest ozone concentration from December to March. We find that the simulated AOT40 target values for protection of vegetation is exceeded even in individual months, especially during November to April. Necessary and effective emission reduction strategies are therefore required to be developed in order to curb the surface level ozone pollution to protect the vegetation from further damage in India whose economy is highly dependent on agricultural sector and may influence the global balance.

  4. pH buffering capacity of acid soils from tropical and subtropical regions of China as influenced by incorporation of crop straw biochars

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Ren-kou; Zhao, An-zhen; Yuan, Jin-hua; Jiang, Jun [Academy of Sciences, Nanjing (China). State Key Lab. of Soil and Sustainable Agriculture

    2012-04-15

    Purpose: The key factors influencing pH buffering capacity of acid soils from tropical and subtropical regions, and effects of soil evolution and incorporation of biochars on pH buffering capacity were investigated to develop suitable methods to increase pH buffering capacity of acid soils. Materials and methods: A total of 24 acid soils collected from southern China were used. The pH buffering capacity was determined using acid-base titration. The values of pH buffering capacity were obtained from the slope of titration curves of acid or alkali additions plotted against pH in the pH range 4.0-7.0. Two biochars were prepared from straws of peanut and canola using a low temperature pyrolysis method. After incubation of three acid soils, pH buffering capacity was then determined. Results and discussion: pH buffering capacity had a range of 9.1-32.1 mmol kg{sup -1} pH{sup -1} for 18 acid soils from tropical and subtropical regions of China. The pH buffering capacity was highly correlated (R{sup 2} = 0.707) with soil cation exchange capacity (CEC) measured with ammonium acetate method at pH 7.0 and decreased with soil evolution due to the decreased CEC. Incorporation of biochars at rates equivalent to 72 and 120 t ha{sup -1} increased soil pH buffering capacity due to the CEC contained in the biochars. Incorporation of peanut straw char which itself contained more CEC and alkalinity induced more increase in soil CEC, and thus greater increase in pH buffering capacity compared with canola straw char. At 5% of peanut straw char added, soil CEC increased by 80.2%, 51.3%, and 82.8% for Ultisol from Liuzhou, Oxisol from Chengmai and Ultisol from Kunlun, respectively, and by 19.8%, 19.6%, and 32.8% with 5% of canola straw char added, respectively; and correspondingly for these soils, the pH buffering capacity increased by 73.6%, 92.0%, and 123.2% with peanut straw char added; and by 31.3%, 25.6%, and 52.3% with canola straw char added, respectively. Protonation

  5. Challenge and opportunities of space-based precipitation radar for spatio-temporal hydrology analysis in tropical maritime influenced catchment: Case study on the hilly tropical watershed of Peninsular Malaysia

    International Nuclear Information System (INIS)

    Mahmud, M R; Numata, S; Matsuyama, H; Hashim, M; Hosaka, T

    2014-01-01

    This paper highlights two critical issues regarding hilly watershed in Peninsular Malaysia; (1) current status of spatio-temporal condition of rain gauge based measurement, and (2) potential of space-based precipitation radar to study the rainfall dynamics. Two analyses were carried out represent each issue consecutively. First, the spatial distribution and efficiency of rain gauge in hilly watershed Peninsular Malaysia is evaluated with respect to the land use and elevation information using Geographical Information System (GIS) approach. Second, the spatial pattern of rainfall changes is analysed using the Tropical Rainfall Measuring Mission (TRMM) satellite information. The spatial analysis revealed that the rain gauge distribution had sparse coverage on hilly watershed and possessed inadequate efficiency for effective spatial based assessment. Significant monthly rainfall changes identified by TRMM satellite on the upper part of the watershed had occurred occasionally in 1999, 2000, 2001, 2006, and 2009 went undetected by conventional rain gauge. This study informed the potential and opportunities of space-based precipitation radar to fill the gaps of knowledge on spatio-temporal rainfall patterns for hydrology and related fields in tropical region

  6. Genetic analysis of growth traits in Polled Nellore cattle raised on pasture in tropical region using Bayesian approaches.

    Science.gov (United States)

    Lopes, Fernando Brito; Magnabosco, Cláudio Ulhôa; Paulini, Fernanda; da Silva, Marcelo Corrêa; Miyagi, Eliane Sayuri; Lôbo, Raysildo Barbosa

    2013-01-01

    Components of (co)variance and genetic parameters were estimated for adjusted weights at ages 120 (W120), 240 (W240), 365 (W365) and 450 (W450) days of Polled Nellore cattle raised on pasture and born between 1987 and 2010. Analyses were performed using an animal model, considering fixed effects: herd-year-season of birth and calf sex as contemporary groups and the age of cow as a covariate. Gibbs Samplers were used to estimate (co)variance components, genetic parameters and additive genetic effects, which accounted for great proportion of total variation in these traits. High direct heritability estimates for the growth traits were revealed and presented mean 0.43, 0.61, 0.72 and 0.67 for W120, W240, W365 and W450, respectively. Maternal heritabilities were 0.07 and 0.08 for W120 and W240, respectively. Direct additive genetic correlations between the weight at 120, 240, 365 and 450 days old were strong and positive. These estimates ranged from 0.68 to 0.98. Direct-maternal genetic correlations were negative for W120 and W240. The estimates ranged from -0.31 to -0.54. Estimates of maternal heritability ranged from 0.056 to 0.092 for W120 and from 0.064 to 0.096 for W240. This study showed that genetic progress is possible for the growth traits we studied, which is a novel and favorable indicator for an upcoming and promising Polled Zebu breed in Tropical regions. Maternal effects influenced the performance of weight at 120 and 240 days old. These effects should be taken into account in genetic analyses of growth traits by fitting them as a genetic or a permanent environmental effect, or even both. In general, due to a medium-high estimate of environmental (co)variance components, management and feeding conditions for Polled Nellore raised at pasture in tropical regions of Brazil needs improvement and growth performance can be enhanced.

  7. Optimal depth-based regional frequency analysis

    Directory of Open Access Journals (Sweden)

    H. Wazneh

    2013-06-01

    Full Text Available Classical methods of regional frequency analysis (RFA of hydrological variables face two drawbacks: (1 the restriction to a particular region which can lead to a loss of some information and (2 the definition of a region that generates a border effect. To reduce the impact of these drawbacks on regional modeling performance, an iterative method was proposed recently, based on the statistical notion of the depth function and a weight function φ. This depth-based RFA (DBRFA approach was shown to be superior to traditional approaches in terms of flexibility, generality and performance. The main difficulty of the DBRFA approach is the optimal choice of the weight function ϕ (e.g., φ minimizing estimation errors. In order to avoid a subjective choice and naïve selection procedures of φ, the aim of the present paper is to propose an algorithm-based procedure to optimize the DBRFA and automate the choice of ϕ according to objective performance criteria. This procedure is applied to estimate flood quantiles in three different regions in North America. One of the findings from the application is that the optimal weight function depends on the considered region and can also quantify the region's homogeneity. By comparing the DBRFA to the canonical correlation analysis (CCA method, results show that the DBRFA approach leads to better performances both in terms of relative bias and mean square error.

  8. Optimal depth-based regional frequency analysis

    Science.gov (United States)

    Wazneh, H.; Chebana, F.; Ouarda, T. B. M. J.

    2013-06-01

    Classical methods of regional frequency analysis (RFA) of hydrological variables face two drawbacks: (1) the restriction to a particular region which can lead to a loss of some information and (2) the definition of a region that generates a border effect. To reduce the impact of these drawbacks on regional modeling performance, an iterative method was proposed recently, based on the statistical notion of the depth function and a weight function φ. This depth-based RFA (DBRFA) approach was shown to be superior to traditional approaches in terms of flexibility, generality and performance. The main difficulty of the DBRFA approach is the optimal choice of the weight function ϕ (e.g., φ minimizing estimation errors). In order to avoid a subjective choice and naïve selection procedures of φ, the aim of the present paper is to propose an algorithm-based procedure to optimize the DBRFA and automate the choice of ϕ according to objective performance criteria. This procedure is applied to estimate flood quantiles in three different regions in North America. One of the findings from the application is that the optimal weight function depends on the considered region and can also quantify the region's homogeneity. By comparing the DBRFA to the canonical correlation analysis (CCA) method, results show that the DBRFA approach leads to better performances both in terms of relative bias and mean square error.

  9. Clinical characteristics of Q fever and etiology of community-acquired pneumonia in a tropical region of southern Taiwan: a prospective observational study.

    Directory of Open Access Journals (Sweden)

    Chung-Hsu Lai

    Full Text Available The clinical characteristics of Q fever are poorly identified in the tropics. Fever with pneumonia or hepatitis are the dominant presentations of acute Q fever, which exhibits geographic variability. In southern Taiwan, which is located in a tropical region, the role of Q fever in community-acquired pneumonia (CAP has never been investigated.During the study period, May 2012 to April 2013, 166 cases of adult CAP and 15 cases of acute Q fever were prospectively investigated. Cultures of clinical specimens, urine antigen tests for Streptococcus pneumoniae and Legionella pneumophila, and paired serologic assessments for Mycoplasma pneumoniae, Chlamydophila pneumoniae, and Q fever (Coxiella burnetii were used for identifying pathogens associated with CAP. From April 2004 to April 2013 (the pre-study period, 122 cases of acute Q fever were also included retrospectively for analysis. The geographic distribution of Q fever and CAP cases was similar. Q fever cases were identified in warmer seasons and younger ages than CAP. Based on multivariate analysis, male gender, chills, thrombocytopenia, and elevated liver enzymes were independent characteristics associated with Q fever. In patients with Q fever, 95% and 13.5% of cases presented with hepatitis and pneumonia, respectively. Twelve (7.2% cases of CAP were seropositive for C. burnetii antibodies, but none of them had acute Q fever. Among CAP cases, 22.9% had a CURB-65 score ≧2, and 45.8% had identifiable pathogens. Haemophilus parainfluenzae (14.5%, S. pneumoniae (6.6%, Pseudomonas aeruginosa (4.8%, and Klebsiella pneumoniae (3.0% were the most common pathogens identified by cultures or urine antigen tests. Moreover, M. pneumoniae, C. pneumoniae, and co-infection with 2 pathogens accounted for 9.0%, 7.8%, and 1.8%, respectively.In southern Taiwan, Q fever is an endemic disease with hepatitis as the major presentation and is not a common etiology of CAP.

  10. Analysis and evaluation of tillage on an alfisol in a semi-arid tropical region of India

    NARCIS (Netherlands)

    Klaij, M.C.

    1983-01-01

    Tillage field experiments were conducted on Alfisols in a semi-arid tropical environment in India. The research was conducted within the framework of the Farming Systems Research Program of the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT).

    To put the

  11. Phytoplankton across Tropical and Subtropical Regions of the Atlantic, Indian and Pacific Oceans.

    Science.gov (United States)

    Estrada, Marta; Delgado, Maximino; Blasco, Dolors; Latasa, Mikel; Cabello, Ana María; Benítez-Barrios, Verónica; Fraile-Nuez, Eugenio; Mozetič, Patricija; Vidal, Montserrat

    2016-01-01

    We examine the large-scale distribution patterns of the nano- and microphytoplankton collected from 145 oceanic stations, at 3 m depth, the 20% light level and the depth of the subsurface chlorophyll maximum, during the Malaspina-2010 Expedition (December 2010-July 2011), which covered 15 biogeographical provinces across the Atlantic, Indian and Pacific oceans, between 35°N and 40°S. In general, the water column was stratified, the surface layers were nutrient-poor and the nano- and microplankton (hereafter phytoplankton, for simplicity, although it included also heterotrophic protists) community was dominated by dinoflagellates, other flagellates and coccolithophores, while the contribution of diatoms was only important in zones with shallow nutriclines such as the equatorial upwelling regions. We applied a principal component analysis to the correlation matrix among the abundances (after logarithmic transform) of the 76 most frequent taxa to synthesize the information contained in the phytoplankton data set. The main trends of variability identified consisted of: 1) A contrast between the community composition of the upper and the lower parts of the euphotic zone, expressed respectively by positive or negative scores of the first principal component, which was positively correlated with taxa such as the dinoflagellates Oxytoxum minutum and Scrippsiella spp., and the coccolithophores Discosphaera tubifera and Syracosphaera pulchra (HOL and HET), and negatively correlated with taxa like Ophiaster hydroideus (coccolithophore) and several diatoms, 2) a general abundance gradient between phytoplankton-rich regions with high abundances of dinoflagellate, coccolithophore and ciliate taxa, and phytoplankton-poor regions (second principal component), 3) differences in dominant phytoplankton and ciliate taxa among the Atlantic, the Indian and the Pacific oceans (third principal component) and 4) the occurrence of a diatom-dominated assemblage (the fourth principal

  12. Phytoplankton across Tropical and Subtropical Regions of the Atlantic, Indian and Pacific Oceans

    Science.gov (United States)

    Estrada, Marta; Delgado, Maximino; Blasco, Dolors; Latasa, Mikel; Cabello, Ana María; Benítez-Barrios, Verónica; Fraile-Nuez, Eugenio; Mozetič, Patricija; Vidal, Montserrat

    2016-01-01

    We examine the large-scale distribution patterns of the nano- and microphytoplankton collected from 145 oceanic stations, at 3 m depth, the 20% light level and the depth of the subsurface chlorophyll maximum, during the Malaspina-2010 Expedition (December 2010-July 2011), which covered 15 biogeographical provinces across the Atlantic, Indian and Pacific oceans, between 35°N and 40°S. In general, the water column was stratified, the surface layers were nutrient-poor and the nano- and microplankton (hereafter phytoplankton, for simplicity, although it included also heterotrophic protists) community was dominated by dinoflagellates, other flagellates and coccolithophores, while the contribution of diatoms was only important in zones with shallow nutriclines such as the equatorial upwelling regions. We applied a principal component analysis to the correlation matrix among the abundances (after logarithmic transform) of the 76 most frequent taxa to synthesize the information contained in the phytoplankton data set. The main trends of variability identified consisted of: 1) A contrast between the community composition of the upper and the lower parts of the euphotic zone, expressed respectively by positive or negative scores of the first principal component, which was positively correlated with taxa such as the dinoflagellates Oxytoxum minutum and Scrippsiella spp., and the coccolithophores Discosphaera tubifera and Syracosphaera pulchra (HOL and HET), and negatively correlated with taxa like Ophiaster hydroideus (coccolithophore) and several diatoms, 2) a general abundance gradient between phytoplankton-rich regions with high abundances of dinoflagellate, coccolithophore and ciliate taxa, and phytoplankton-poor regions (second principal component), 3) differences in dominant phytoplankton and ciliate taxa among the Atlantic, the Indian and the Pacific oceans (third principal component) and 4) the occurrence of a diatom-dominated assemblage (the fourth principal

  13. Seasonal variability of planktonic copepods (Copepoda: Crustacea in a tropical estuarine region in Brazil

    Directory of Open Access Journals (Sweden)

    Cristina de Oliveira Dias

    2009-12-01

    Full Text Available The Caravelas River estuary and adjacent coastal region were studied during the rainy and dry seasons of 2003-2004 to assess the copepod community structure. Abiotic and biotic parameters were measured, and the total density, frequency and percentage of copepod taxa were determined for each sampling period. Copepod densities showed significant differences between sampling periods, with higher densities in the rainy seasons (Mean: 90,941.80 ind.m-3; S.D.: 26,364.79. The sampling stations located to the north and south, in the coastal region adjacent to the Caravelas River estuary presented the lowest copepod density values. The copepod assemblage was composed mainly of estuarine and estuarine/coastal copepods. The seasonal variations in temperature and salinity influenced the abundance of species during the rainy and dry seasons, with the following dominant species alternating: Paracalanus quasimodo Bowman, 1971 in the rainy season of 2003, Parvocalanus crassirostris Dahl, 1894 in the dry season of 2003 and Acartia lilljeborgii Giesbrecht, 1892 in the rainy and dry seasons of 2004. Non-parametric multidimensional scaling indicated differences in copepod assemblages between sampling periods, but not between sampling stations.

  14. Investigation of Long-Term Impacts of Urbanization when Considering Global Warming for a Coastal Tropical Region

    Science.gov (United States)

    Gonalez, Jorge E.; Comarazamy, Daniel E.; Luvall, Jeffrey C.; Rickman, Douglas L.; Smith, T.

    2010-01-01

    The overachieving goal of this project is to gain a better understanding of the climate impacts caused by the combined effects of land cover and land use (LCLU) changes and increasing global concentrations of green house gases (GHG) in tropical coastal areas, regions where global, regional and local climate phenomena converge, taking as the test case the densely populated northeast region of the Caribbean island of Puerto Rico. The research uses an integrated approach of high-resolution remote sensing information linked to a high resolution Regional Atmospheric Modeling System (RAMS), which was employed to perform ensembles of climate simulations (combining 2-LCLU and 2-GHG concentration scenarios). Reconstructed agricultural maps are used to define past LCLU, and combined with reconstructed sea surface temperatures (SST) for the same period form the PAST climate scenario (1951-1956); while the PRESENT scenario (2000-2004) was additionally supported by high resolution remote sensing data (10-m-res). The climate reconstruction approach is validated with available observed climate data from surface weather stations for both periods of time simulated. The selection of the past and present climate scenarios considers large-scale biases (i.e. ENSO/NAO) as reflected in the region of interest. Direct and cross comparison of the results is allowing quantifying single, combined, and competitive effects. Results indicate that global GHG have dominant effects on minimum temperatures (following regional tendencies), while urban sprawl dominates maximum temperatures. To further investigate impacts of land use the Bowen Ratio and the thermal response number (TRN) are analyzed. The Bowen ratio indicates that forestation of past agricultural high areas have an overwhelmingly mitigation effect on increasing temperatures observed in different LCLU scenarios, but when abandoned agricultural lands are located in plains, the resulting shrub/grass lands produce higher surface

  15. Energy reduction in buildings in temperate and tropic regions utilizing a heat loss measuring device

    DEFF Research Database (Denmark)

    Sørensen, Lars Schiøtt

    2012-01-01

    There exist two ordinary ways to obtain global energy efficiency. One way is to make improvements on the energy production and supply side, and the other way is, in general, to reduce the consume of energy in the society. This paper has focus on the latter and especially the consume of energy...... for heating up, and cooling down our houses. There is a huge energy saving potential on this area reducing both the World climate problems and economy challenges as well. Heating of buildings in Denmark counts for approximately 40% of the entire national energy consume. Of this reason a reduction of heat...... losses from building envelopes are of great impor­tance in order to reach the Bologna CO2-emission reduction goals. Energy renovation of buildings is a topic of huge focus around the world these years. Not only expenses for heating in the tempered and arctic regions are of importance, but also expenses...

  16. Spatial patterns of diversity at local and regional scales in a tropical lagoon

    Directory of Open Access Journals (Sweden)

    José Adán Caballero-Vázquez

    Full Text Available The present study reports estimates of alpha (α, beta (β and gamma (Γ diversity for the fish community of Chacmochuch Lagoon (SE Mexico, a natural protected area located in the northern portion of the Mesoamerican Barrier Reef System. Fish specimens were sampled in 2004 and 2006. Field work was carried out at three climatic peaks: at 13 stations using a 70 m-long beach seine. The collected data were supplemented with information obtained from a previous work conducted in 2002 and were then analyzed with multivariate statistical methods. In addition, fish composition results from this study were compared to those reported for other similar ecosystems of the region. A total of 68 fish species were recorded, determined as peripheral (high-salinity species, usually marine affinity most of them. Most of the fish species collected were determined as rare, and a few number of species were determined as common and dominant. Salinity, TSD, temperature, dissolved oxygen and other variables were measured to determine the influence over the fish communities, four groups of sites where determined. Results indicated a gradual decrease in the degree of species replacement towards the interior of the system (away from the coast. The estimated value of gamma diversity was high compared to that reported for other coastal systems of the region and, due to the high degree of habitat heterogeneity found in this system; beta diversity had a greater contribution to gamma diversity than alpha diversity. This lagoon acts as a nursing area for many of the fish species collected in this study as indicated by the presence of juvenile stages.

  17. Draft genome sequence of bitter gourd (Momordica charantia), a vegetable and medicinal plant in tropical and subtropical regions.

    Science.gov (United States)

    Urasaki, Naoya; Takagi, Hiroki; Natsume, Satoshi; Uemura, Aiko; Taniai, Naoki; Miyagi, Norimichi; Fukushima, Mai; Suzuki, Shouta; Tarora, Kazuhiko; Tamaki, Moritoshi; Sakamoto, Moriaki; Terauchi, Ryohei; Matsumura, Hideo

    2017-02-01

    Bitter gourd (Momordica charantia) is an important vegetable and medicinal plant in tropical and subtropical regions globally. In this study, the draft genome sequence of a monoecious bitter gourd inbred line, OHB3-1, was analyzed. Through Illumina sequencing and de novo assembly, scaffolds of 285.5 Mb in length were generated, corresponding to ∼84% of the estimated genome size of bitter gourd (339 Mb). In this draft genome sequence, 45,859 protein-coding gene loci were identified, and transposable elements accounted for 15.3% of the whole genome. According to synteny mapping and phylogenetic analysis of conserved genes, bitter gourd was more related to watermelon (Citrullus lanatus) than to cucumber (Cucumis sativus) or melon (C. melo). Using RAD-seq analysis, 1507 marker loci were genotyped in an F2 progeny of two bitter gourd lines, resulting in an improved linkage map, comprising 11 linkage groups. By anchoring RAD tag markers, 255 scaffolds were assigned to the linkage map. Comparative analysis of genome sequences and predicted genes determined that putative trypsin-inhibitor and ribosome-inactivating genes were distinctive in the bitter gourd genome. These genes could characterize the bitter gourd as a medicinal plant. © The Author 2016. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

  18. Pu Radioisotopes and 241Am as Alternative Chronostratigraphic Markers in Tropical Regions: An Application in Havana Bay (Cuba)

    International Nuclear Information System (INIS)

    Alvarado, J.A. Corcho; Froidevaux, P.; Bochud, F.; Diaz-Asencio, M.; Hernandez, C.M. Alonso; Sanchez-Cabeza, J.A.

    2011-01-01

    The low 137 Cs activity observed in marine sediments of tropical regions often precludes its use as chronostratigraphic marker. Here we present a study on the use of Pu and Am radioisotopes as alternative markers to constrain the 210 Pb ages in a sediment core of the Havana Bay (Cuba). Mean activity ratios of 238 Pu/ 239,240 Pu, 241 Am/ 239,240 Pu and 241 Pu/ 239 , 240 Pu indicated that the nuclear weapon tests (NWT) fallout is the main source of the anthropogenic radionuclides. While the inventory of 137 Cs in the sediments is lower than the expected fallout inventory, 239,240 Pu accumulates in the sediments with inventories higher than the expected fallout inventory. The high fluxes of 239,240 Pu are nevertheless corroborated here through use of 210 Pb, and confirm that focusing of solid particles is of great importance in the investigated site. 239,240 Pu showed to be a useful time tracer in marine sites where the 137 Cs signal is very low. (author)

  19. Oceanic, Latitudinal, and Sex-Specific Variation in Demography of a Tropical Deepwater Snapper across the Indo-Pacific Region

    Directory of Open Access Journals (Sweden)

    Ashley J. Williams

    2017-12-01

    Full Text Available Deepwater tropical fisheries provide an important source of income and protein to Pacific and Indian Ocean coastal communities who are highly dependent on fish for food security. The development of quantitative assessments and management strategies for these deepwater fisheries has been hindered by insufficient biological and fisheries data. We examine the age-specific demography of the pygmy ruby snapper Etelis carbunculus, an important target species in tropical deepwater fisheries, across 90° of longitude and 20° of latitude in the Pacific and Indian Oceans. Our results show that growth of E. carbunculus varies significantly between oceans and sexes and across latitudes in both oceans. Estimates of natural and fishing mortality were similar between oceans, but higher for females than males in both oceans. Evidence of greater fishing pressure on females than males is likely due to the larger size-at-age of females compared to males, assuming that selectivity of the fishing gear is related directly to fish size. Sex ratios were significantly female biased in both oceans despite this species being gonochoristic, and maturity schedules were similar between sexes in the Pacific Ocean. This species exhibits a protracted spawning season from mid-spring to autumn (i.e., October to May in the Pacific Ocean. These results represent the first estimates of age-specific demographic parameters for E. carbunculus, and provide the foundation for the development of the first species-specific assessment models and harvest strategies for the species. Future stock assessment models for E. carbunculus should consider sex-specific demographic parameters and spatial variation in demography. Our results reveal substantial differences in biology between E. carbunculus and the giant ruby snapper E. sp., a cryptic congeneric species, and thus contribute to greater clarity in managing fisheries that are dependent on these two species. Furthermore, the improved

  20. Anvil Productivities of Tropical Deep Convective Clusters and Their Regional Differences

    Directory of Open Access Journals (Sweden)

    Deng Min

    2016-01-01

    The total anvil clouds detrained from convection counts for 0.4 to 0.8 of the cluster horizontal scale, 0.2 to 0.6 of the cluster cross section volume, and 0.05 to 0.20 of the cluster ice mass, depending on the cluster scales and height. There are two main detrainment layers. When the convective clusters is less than about 100 km, the anvil clouds are mainly detrained at about 6-8 km with a spreading ratio (ratio of maximum cluster width to convection rainy core width less than 1.5. When convective clusters becomes 100 km or wider, it reaches the dominate detrainment layer at about 12 km, the detrainment index increase from 2 to more 6. Among 8 regions, convection clusters in MA produce the most anvil volume fraction. The more the ice mass is pumped upward in the anvil clouds till clusters are about 500 km wider. Nevertheless, the anvil ice mass pumped above 15 km is less than 0.1% of the total ice mass in the convective cluster.

  1. The ability of general circulation models to simulate tropical cyclones and their precursors over the North Atlantic main development region

    Energy Technology Data Exchange (ETDEWEB)

    Daloz, Anne Sophie; Chauvin, Fabrice [Groupe de Modelisation Grande Echelle et Climat, CNRM-GAME, Meteo-France, Toulouse Cedex 1 (France); Walsh, Kevin [University of Melbourne, School of Earth Sciences, Melbourne, VIC (Australia); Lavender, Sally; Abbs, Deborah [CSIRO Atmospheric and Marine Research, Aspendale, VIC (Australia); Roux, Frank [Universite de Toulouse and Centre National de la Recherche Scientifique, Laboratoire d' Aerologie, Toulouse (France)

    2012-10-15

    The ability of General Circulation Models (GCMs) to generate Tropical Cyclones (TCs) over the North Atlantic Main Development Region (MDR; 10-20 N, 20-80 W; Goldenberg and Shapiro in J Clim 9:1169-1187, 1996) is examined through a subset of ocean-atmosphere coupled simulations from the World Climate Research Programme (WCRP) Coupled Model Intercomparison Project phase 3 (CMIP3) multimodel data set and a high-resolution (0.5 ) Sea Surface Temperature (SST)-forced simulation from the Australian Conformal-Cubic Atmospheric Model GCM. The results are compared with National Center for Environmental Prediction (NCEP-2) and European Center for Medium Range Weather Forecasts Re-Analysis (ERA-40) reanalyses over a common period from 1980 to 1998. Important biases in the representation of the TC activity are encountered over the MDR. This study emphasizes the strong link in the GCMs between African Easterly Waves (AEWs) and TC activity in this region. However, the generation of AEWs is not a sufficient condition alone for the models to produce TCs. Precipitation over the Sahel, especially rainfall over the Fouta Djallon highlands (cf. Fig. 1), is playing a role in the generation of TCs over the MDR. The influence of large-scale fields such as SST, vertical wind shear and tropospheric humidity on TC genesis is also examined. The ability of TC genesis indices, such as the Genesis Potential Index and the Convective Yearly Genesis Potential, to represent TC activity over the MDR in simulations at low to high spatial resolutions is analysed. These indices are found to be a reasonable method for comparing cyclogenesis in different models, even though other factors such as AEW activity should also be considered. (orig.)

  2. A review of nickel toxicity to marine and estuarine tropical biota with particular reference to the South East Asian and Melanesian region.

    Science.gov (United States)

    Gissi, Francesca; Stauber, Jennifer L; Binet, Monique T; Golding, Lisa A; Adams, Merrin S; Schlekat, Christian E; Garman, Emily R; Jolley, Dianne F

    2016-11-01

    The South East Asian Melanesian (SEAM) region contains the world's largest deposits of nickel lateritic ores. Environmental impacts may occur if mining operations are not adequately managed. Effects data for tropical ecosystems are required to assess risks of contaminant exposure and to derive water quality guidelines (WQG) to manage these risks. Currently, risk assessment tools and WQGs for the tropics are limited due to the sparse research on how contaminants impact tropical biota. As part of a larger project to develop appropriate risk assessment tools to ensure sustainable nickel production in SEAM, nickel effects data were required. The aim of this review was to compile data on the effects of nickel on tropical marine, estuarine, pelagic and benthic species, with a particular focus on SEAM. There were limited high quality chronic nickel toxicity data for tropical marine species, and even fewer for those relevant to SEAM. Of the data available, the most sensitive SEAM species to nickel were a sea urchin, copepod and anemone. There is a significant lack of high quality chronic data for several ecologically important taxonomic groups including cnidarians, molluscs, crustaceans, echinoderms, macroalgae and fish. No high quality chronic nickel toxicity data were available for estuarine waters or marine and estuarine sediments. The very sparse toxicity data for tropical species limits our ability to conduct robust ecological risk assessment and may require additional data generation or read-across from similar species in other databases (e.g. temperate) to fill data gaps. Recommendations on testing priorities to fill these data gaps are presented. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. On the use of nudging techniques for regional climate modeling: application for tropical convection

    Science.gov (United States)

    Pohl, Benjamin; Crétat, Julien

    2014-09-01

    Using a large set of WRF ensemble simulations at 70-km horizontal resolution over a domain encompassing the Warm Pool region and its surroundings [45°N-45°S, 10°E-240°E], this study aims at quantifying how nudging techniques can modify the simulation of deep atmospheric convection. Both seasonal mean climate, transient variability at intraseasonal timescales, and the respective weight of internal (stochastic) and forced (reproducible) variability are considered. Sensitivity to a large variety of nudging settings (nudged variables and layers and nudging strength) and to the model physics (using 3 convective parameterizations) is addressed. Integrations are carried out during a 7-month season characterized by neutral background conditions and strong intraseasonal variability. Results show that (1) the model responds differently to the nudging from one parameterization to another. Biases are decreased by ~50 % for Betts-Miller-Janjic convection against 17 % only for Grell-Dévényi, the scheme producing yet the largest biases; (2) relaxing air temperature is the most efficient way to reduce biases, while nudging the wind increases most co-variability with daily observations; (3) the model's internal variability is drastically reduced and mostly depends on the nudging strength and nudged variables; (4) interrupting the relaxation before the end of the simulations leads to an abrupt convergence towards the model's natural solution, with no clear effects on the simulated climate after a few days. The usefulness and limitations of the approach are finally discussed through the example of the Madden-Julian Oscillation, that the model fails at simulating and that can be artificially and still imperfectly reproduced in relaxation experiments.

  4. Helminthiasis characterization and anthelmintic efficacy for ewes and lambs raised in tropical semiarid region.

    Science.gov (United States)

    Bastos, Gabriela Almeida; Fonseca, Leydiana Duarte; de Paiva Ferreira, Adriano Vinícius; Costa, Marco Aurélio Morais Soares; Silva, Maria Luiza França; de Oliveira Vasconcelos, Viviane; de Sousa, Rogério Marcos; Duarte, Eduardo Robson

    2017-06-01

    In this study the helminthiasis and anthelmintic effectiveness in ewes and lambs were evaluated in a semiarid region of Brazil. Twelve sheep farms were investigated using semi-structured questionnaires and fecal egg count (FEC) reduction test was employed to analyze the profile of anthelmintic resistance. Groups of at least 10 animals with FEC ≥ 300 were selected. After 12 h of fasting, homogeneous groups of lambs or ewes were treated with albendazole, levamisole moxidectin, or oxfendazole and control groups were not treated. Feces were collected before treatments and 14 days after, and larvae genera were identified after cuprocultures in both periods. Extensive grazing was the predominant creation system, using hybrid Santa Ines animals. The separation by age was promoted in 75% of herds; however, maternity pickets there were only in three farms. The strategic treatments were performed only in 8.4% of sheep farms and 16.6% used the anthelmintic efficacy test and alternated anthelmintic classes after 1 year. The initial FEC means for lambs were significantly higher than ewe FEC averages. For lamb tests, moxidectin and levamisole showed higher efficacy (p ≤ 0.05) than benzimidazoles. For ewe tests, moxidectin and levamisole showed efficiencies >75%. Haemonchus spp. and Trichostrongylus spp. were the most frequent nematodes before treatments and the genus Haemonchus was the most prevalent after anthelmintic treatments (p < 0.05). Variations of anthelmintic susceptibility were observed for categories and herds evaluated, which emphasizes the importance of the effectiveness tests for the choice of anthelmintics for ewes and lambs.

  5. 'Combating' tropical diseases in the German colonial press.

    Science.gov (United States)

    Correa, Sílvio Marcus de Souza

    2013-03-01

    This article shows how much certain German language newspapers were a vehicule for reporting to the lay public on 'combating' tropical diseases. Through the press, immigrants and their descendents in Brazil were informed not only about the diseases which afflicted German colonists in Africa, but also about measures concerning sanitation, prophylaxis and experiments with tropical medicine, etc. Based on hemerographic sources, it shows how successful the overseas German communities were in sharing their experiences regarding health in tropical and/or sub-tropical regions.

  6. Design of Tropical Flowers Environmental Parameters Wireless Monitoring System Based on MSP430

    Directory of Open Access Journals (Sweden)

    Huang Jian-Qing

    2016-01-01

    Full Text Available Considering the importance of real-time monitoring tropical flower environment parameters, the paper designs a wireless monitoring system based on MSP430F149 for tropical flower growing parameters. The proposed system uses sensor nodes to obtain data of temperature, humidity and light intensity, sink node to collect data from sensor nodes through wireless sensor network, and monitoring center to process data downloaded from the sink node through RS232 serial port. The node hardware platform is composed of a MSP430F149 processor, AM2306 and NHZD10AI sensors used to adopt temperature, humidity and light intensity data, and an nRF905 RF chip used to receive and send data. The node software, operated in IAR Embedded Workbench, adopts C Language to do node data collection and process, wireless transmission and serial port communication. The software of monitoring center develops in VB6.0, which can provide vivid and explicit real-time monitoring platform for flower farmers.

  7. Regional modelling of tracer transport by tropical convection – Part 1: Sensitivity to convection parameterization

    Directory of Open Access Journals (Sweden)

    J. Arteta

    2009-09-01

    Full Text Available The general objective of this series of papers is to evaluate long duration limited area simulations with idealised tracers as a tool to assess tracer transport in chemistry-transport models (CTMs. In this first paper, we analyse the results of six simulations using different convection closures and parameterizations. The simulations are using the Grell and Dévényi (2002 mass-flux framework for the convection parameterization with different closures (Grell = GR, Arakawa-Shubert = AS, Kain-Fritch = KF, Low omega = LO, Moisture convergence = MC and an ensemble parameterization (EN based on the other five closures. The simulations are run for one month during the SCOUT-O3 field campaign lead from Darwin (Australia. They have a 60 km horizontal resolution and a fine vertical resolution in the upper troposphere/lower stratosphere. Meteorological results are compared with satellite products, radiosoundings and SCOUT-O3 aircraft campaign data. They show that the model is generally in good agreement with the measurements with less variability in the model. Except for the precipitation field, the differences between the six simulations are small on average with respect to the differences with the meteorological observations. The comparison with TRMM rainrates shows that the six parameterizations or closures have similar behaviour concerning convection triggering times and locations. However, the 6 simulations provide two different behaviours for rainfall values, with the EN, AS and KF parameterizations (Group 1 modelling better rain fields than LO, MC and GR (Group 2. The vertical distribution of tropospheric tracers is very different for the two groups showing significantly more transport into the TTL for Group 1 related to the larger average values of the upward velocities. Nevertheless the low values for the Group 1 fluxes at and above the cold point level indicate that the model does not simulate significant overshooting. For stratospheric tracers

  8. Strategic grazing management towards sustainable intensification at tropical pasture-based dairy systems.

    Science.gov (United States)

    Congio, Guilhermo F S; Batalha, Camila D A; Chiavegato, Marília B; Berndt, Alexandre; Oliveira, Patrícia P A; Frighetto, Rosa T S; Maxwell, Thomas M R; Gregorini, Pablo; Da Silva, Sila C

    2018-05-01

    Agricultural systems are responsible for environmental impacts that can be mitigated through the adoption of more sustainable principles. Our objective was to investigate the influence of two pre-grazing targets (95% and maximum canopy light interception during pasture regrowth; LI 95% and LI Max , respectively) on sward structure and herbage nutritive value of elephant grass cv. Cameroon, and dry matter intake (DMI), milk yield, stocking rate, enteric methane (CH 4 ) emissions by Holstein × Jersey dairy cows. We hypothesized that grazing strategies modifying the sward structure of elephant grass (Pennisetum purpureum Schum.) improves nutritive value of herbage, increasing DMI and reducing intensity of enteric CH 4 emissions, providing environmental and productivity benefits to tropical pasture-based dairy systems. Results indicated that pre-sward surface height was greater for LI Max (≈135 cm) than LI 95% (≈100 cm) and can be used as a reliable field guide for monitoring sward structure. Grazing management based on LI 95% criteria improved herbage nutritive value and grazing efficiency, allowing greater DMI, milk yield and stocking rate by dairy cows. Daily enteric CH 4 emission was not affected; however, cows grazing elephant grass at LI 95% were more efficient and emitted 21% less CH 4 /kg of milk yield and 18% less CH 4 /kg of DMI. The 51% increase in milk yield per hectare overcame the 29% increase in enteric CH 4 emissions per hectare in LI 95% grazing management. Thereby the same resource allocation resulted in a 16% mitigation of the main greenhouse gas from pasture-based dairy systems. Overall, strategic grazing management is an environmental friendly practice that improves use efficiency of allocated resources through optimization of processes evolving plant, ruminant and their interface, and enhances milk production efficiency of tropical pasture-based systems. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. Bacterial contamination of automotive fuels in a tropical region: the case of Costa Rica

    Directory of Open Access Journals (Sweden)

    Carlos E Rodríguez-Rodríguez

    2009-09-01

    (including all from diesel tanks, indicating biocorrosion processes risk in fuel transport and storage systems. From the findings in this study it is recommended to give a frequent maintenance to fuel containers, based on continuous drainage and removal of accumulated water, antimicrobial agent addition and microbial quality monitoring in country’s fuels. Rev. Biol. Trop. 57 (3: 489-504. Epub 2009 September 30.Se evaluó semestralmente durante dos años la calidad bacteriana de los combustibles almacenados en los cuatro planteles de la Refinadora Costarricense de Petróleo (Costa Rica. Para un total de 96 muestras se realizaron recuentos (norma ASTM D6974-04 e identificación de las bacterias presentes en gasolina regular, gasolina súper y diesel en los niveles superior e inferior de los tanques contenedores; en las muestras con fase acuosa se cuantificaron las bacterias reductoras de sulfato (SRB, norma ASTM D4412-84. La mayor contaminación se observó en el fondo de los tanques, sobretodo si se presentó una capa de agua almacenada. El diesel fue el combustible más contaminado, sin embargo, no se observó alteración importante en los parámetros fisicoquímicos de las muestras evaluadas. Se aislaron 149 cepas, 136 (91.3% Gram positivas y 13 (8.7% Gram negativas; los géneros más frecuentes fueron Staphylococcus (24.0%, Micrococcus (21.9%, Bacillus (18.8%, Kocuria (11.5% y Pseudomonas (7.3%. Con bajas frecuencias se encontraron algunas especies para las que no se ha descrito su aparición o crecimiento en hidrocarburos. Las SRB se presentaron con recuentos de hasta 105 MPN/l en un 42.9% de las muestras con agua residual, principalmente en diesel, lo cual es indicativo de alerta por biocorrosión. A partir de los resultados se recomienda dar un mantenimiento frecuente a los contenedores, la adición de compuestos antimicrobianos y el monitoreo de la calidad microbiana de los combustibles del país.

  10. Predictability of CFSv2 in the tropical Indo-Pacific region, at daily and subseasonal time scales

    Science.gov (United States)

    Krishnamurthy, V.

    2018-06-01

    The predictability of a coupled climate model is evaluated at daily and intraseasonal time scales in the tropical Indo-Pacific region during boreal summer and winter. This study has assessed the daily retrospective forecasts of the Climate Forecast System version 2 from the National Centers of Environmental Prediction for the period 1982-2010. The growth of errors in the forecasts of daily precipitation, monsoon intraseasonal oscillation (MISO) and the Madden-Julian oscillation (MJO) is studied. The seasonal cycle of the daily climatology of precipitation is reasonably well predicted except for the underestimation during the peak of summer. The anomalies follow the typical pattern of error growth in nonlinear systems and show no difference between summer and winter. The initial errors in all the cases are found to be in the nonlinear phase of the error growth. The doubling time of small errors is estimated by applying Lorenz error formula. For summer and winter, the doubling time of the forecast errors is in the range of 4-7 and 5-14 days while the doubling time of the predictability errors is 6-8 and 8-14 days, respectively. The doubling time in MISO during the summer and MJO during the winter is in the range of 12-14 days, indicating higher predictability and providing optimism for long-range prediction. There is no significant difference in the growth of forecasts errors originating from different phases of MISO and MJO, although the prediction of the active phase seems to be slightly better.

  11. Impact of Restoration of Soil in a Humid Tropical Region on Storage of Organic Carbon in a Recalcitrant Pool

    Science.gov (United States)

    Jyoti Nath, Arun; Brahma, Biplab; Lal, Rattan; Das, Ashesh Kumar

    2017-04-01

    Quantifying soil organic carbon (SOC) changes through restoration of degraded lands is important to assessing the changes in soil properties. However, SOC measures all C fractions and its assessment is not adequate to distinguish between the more dynamic or active C (AC) fractions and the recalcitrant or passive C (PC) form. SOC fractions comprising of the recalcitrant pools have been suggested as a driver for long term soil C sink management. Therefore, the present study was undertaken at a site within the North Eastern India (NEI) region with an objective to explore whether or not SOC fractions change with restoration of degraded lands under humid tropical climate. An age-chronosequence study was established comprising of four different aged rubber plantations (6, 15, 27 and 34 yr. old) planted on Imperata grasslands. The site was selected to study changes in the different fractions of SOC and total SOC stock, and the data were compared with that of a native forest. The data indicated that the SOC stock increased from 106 Mg ha-1 under 6 yr. to 130 Mg ha-1 under 34 yr. old plantations. The SOC stock after 34 yr. of plantation was 20% higher than that under Imperata grassland, but was 34% lower than that under the native forest soil. With respect to lability of C fractions, proportion of AC pool decreased linearly with increase in plantation age from 59 % under 6 yr to 33 % under 34 yr. old plantations. In contrast, proportion of PC pool increased from 41 % of SOC stock under 6 yr. to 67 % of SOC under 34 yr. old plantations, suggesting the significant role of old aged plantation in C sink management.

  12. National satellite-based humid tropical forest change assessment in Peru in support of REDD+ implementation

    Science.gov (United States)

    Potapov, P. V.; Dempewolf, J.; Talero, Y.; Hansen, M. C.; Stehman, S. V.; Vargas, C.; Rojas, E. J.; Castillo, D.; Mendoza, E.; Calderón, A.; Giudice, R.; Malaga, N.; Zutta, B. R.

    2014-12-01

    Transparent, consistent, and accurate national forest monitoring is required for successful implementation of reducing emissions from deforestation and forest degradation (REDD+) programs. Collecting baseline information on forest extent and rates of forest loss is a first step for national forest monitoring in support of REDD+. Peru, with the second largest extent of Amazon basin rainforest, has made significant progress in advancing its forest monitoring capabilities. We present a national-scale humid tropical forest cover loss map derived by the Ministry of Environment REDD+ team in Peru. The map quantifies forest loss from 2000 to 2011 within the Peruvian portion of the Amazon basin using a rapid, semi-automated approach. The available archive of Landsat imagery (11 654 scenes) was processed and employed for change detection to obtain annual gross forest cover loss maps. A stratified sampling design and a combination of Landsat (30 m) and RapidEye (5 m) imagery as reference data were used to estimate the primary forest cover area, total gross forest cover loss area, proportion of primary forest clearing, and to validate the Landsat-based map. Sample-based estimates showed that 92.63% (SE = 2.16%) of the humid tropical forest biome area within the country was covered by primary forest in the year 2000. Total gross forest cover loss from 2000 to 2011 equaled 2.44% (SE = 0.16%) of the humid tropical forest biome area. Forest loss comprised 1.32% (SE = 0.37%) of primary forest area and 9.08% (SE = 4.04%) of secondary forest area. Validation confirmed a high accuracy of the Landsat-based forest cover loss map, with a producer’s accuracy of 75.4% and user’s accuracy of 92.2%. The majority of forest loss was due to clearing (92%) with the rest attributed to natural processes (flooding, fires, and windstorms). The implemented Landsat data processing and classification system may be used for operational annual forest cover loss updates at the national level for REDD

  13. National satellite-based humid tropical forest change assessment in Peru in support of REDD+ implementation

    International Nuclear Information System (INIS)

    Potapov, P V; Dempewolf, J; Talero, Y; Hansen, M C; Stehman, S V; Vargas, C; Rojas, E J; Calderón, A; Giudice, R; Malaga, N; Zutta, B R; Castillo, D; Mendoza, E

    2014-01-01

    Transparent, consistent, and accurate national forest monitoring is required for successful implementation of reducing emissions from deforestation and forest degradation (REDD+) programs. Collecting baseline information on forest extent and rates of forest loss is a first step for national forest monitoring in support of REDD+. Peru, with the second largest extent of Amazon basin rainforest, has made significant progress in advancing its forest monitoring capabilities. We present a national-scale humid tropical forest cover loss map derived by the Ministry of Environment REDD+ team in Peru. The map quantifies forest loss from 2000 to 2011 within the Peruvian portion of the Amazon basin using a rapid, semi-automated approach. The available archive of Landsat imagery (11 654 scenes) was processed and employed for change detection to obtain annual gross forest cover loss maps. A stratified sampling design and a combination of Landsat (30 m) and RapidEye (5 m) imagery as reference data were used to estimate the primary forest cover area, total gross forest cover loss area, proportion of primary forest clearing, and to validate the Landsat-based map. Sample-based estimates showed that 92.63% (SE = 2.16%) of the humid tropical forest biome area within the country was covered by primary forest in the year 2000. Total gross forest cover loss from 2000 to 2011 equaled 2.44% (SE = 0.16%) of the humid tropical forest biome area. Forest loss comprised 1.32% (SE = 0.37%) of primary forest area and 9.08% (SE = 4.04%) of secondary forest area. Validation confirmed a high accuracy of the Landsat-based forest cover loss map, with a producer’s accuracy of 75.4% and user’s accuracy of 92.2%. The majority of forest loss was due to clearing (92%) with the rest attributed to natural processes (flooding, fires, and windstorms). The implemented Landsat data processing and classification system may be used for operational annual forest cover loss updates at the national level

  14. Technical Note: Approximate Bayesian parameterization of a process-based tropical forest model

    Science.gov (United States)

    Hartig, F.; Dislich, C.; Wiegand, T.; Huth, A.

    2014-02-01

    Inverse parameter estimation of process-based models is a long-standing problem in many scientific disciplines. A key question for inverse parameter estimation is how to define the metric that quantifies how well model predictions fit to the data. This metric can be expressed by general cost or objective functions, but statistical inversion methods require a particular metric, the probability of observing the data given the model parameters, known as the likelihood. For technical and computational reasons, likelihoods for process-based stochastic models are usually based on general assumptions about variability in the observed data, and not on the stochasticity generated by the model. Only in recent years have new methods become available that allow the generation of likelihoods directly from stochastic simulations. Previous applications of these approximate Bayesian methods have concentrated on relatively simple models. Here, we report on the application of a simulation-based likelihood approximation for FORMIND, a parameter-rich individual-based model of tropical forest dynamics. We show that approximate Bayesian inference, based on a parametric likelihood approximation placed in a conventional Markov chain Monte Carlo (MCMC) sampler, performs well in retrieving known parameter values from virtual inventory data generated by the forest model. We analyze the results of the parameter estimation, examine its sensitivity to the choice and aggregation of model outputs and observed data (summary statistics), and demonstrate the application of this method by fitting the FORMIND model to field data from an Ecuadorian tropical forest. Finally, we discuss how this approach differs from approximate Bayesian computation (ABC), another method commonly used to generate simulation-based likelihood approximations. Our results demonstrate that simulation-based inference, which offers considerable conceptual advantages over more traditional methods for inverse parameter estimation

  15. Tropical-Extratropical Exchange Based on Argo Profiles and Ship-Based Observations Near the Western Boundary

    Science.gov (United States)

    Yuan, D.; Li, B.; Yang, L.

    2014-12-01

    The tropical-extratropical exchange in the northwestern Pacific Ocean is studied using the absolute geostrophic currents based on Argo Profiles and the observations of the western boundary currents (WBCs) during two cruises in the winters of 2010 and 2012. The absolute geostrophic currents are calculated using the P-vector method for the period of 2004 through 2011. The transport of the geostrophic currents is compared with the Sverdrup theory and found to differ significantly in several locations. Analyses have shown that errors of wind stress estimation cannot account for all of the differences. The largest differences are found in the area, where nonlinear activities are vigorous. It is, therefore, suggested that the linear dynamics of the Sverdrup theory is deficient in explaining the geostrophic transport of the tropical northwestern Pacific Ocean. Previous studies suggest recharge and discharge of the tropical Pacific Ocean heat content through the interior circulation of the North Pacific Ocean, based on the Sverdrup theory, and that the WBCs play the role opposite to the interior ocean recharge and discharge anomalies. Using ocean observations from two cruises in a La Niña winter and a normal winter, it is suggested that the Kuroshio transport decreases significantly and the Mindanao Current transport increases significantly at the peak of 2010 La Niña, opposite to the prediction of existing theory. The anomalies of the western boundary current transport are found much larger than those of the meridional circulation in the entire interior of the North Pacific Ocean, the dynamics of which are suggested to be associated with the Kelvin wave propagation around the Philippine islands. The results suggest that the WBCs dominate the interannual recharge and discharge of the western Pacific warm pool during the 2010 La Niña.

  16. Global composites of surface wind speeds in tropical cyclones based on a 12 year scatterometer database

    Science.gov (United States)

    Klotz, Bradley W.; Jiang, Haiyan

    2016-10-01

    A 12 year global database of rain-corrected satellite scatterometer surface winds for tropical cyclones (TCs) is used to produce composites of TC surface wind speed distributions relative to vertical wind shear and storm motion directions in each TC-prone basin and various TC intensity stages. These composites corroborate ideas presented in earlier studies, where maxima are located right of motion in the Earth-relative framework. The entire TC surface wind asymmetry is down motion left for all basins and for lower strength TCs after removing the motion vector. Relative to the shear direction, the motion-removed composites indicate that the surface wind asymmetry is located down shear left for the outer region of all TCs, but for the inner-core region it varies from left of shear to down shear right for different basin and TC intensity groups. Quantification of the surface wind asymmetric structure in further stratifications is a necessary next step for this scatterometer data set.

  17. Objective Tracking of Tropical Cyclones in the North-West Pacific Basin Based on Wind Field Information only

    Science.gov (United States)

    Leckebusch, G. C.; Befort, D. J.; Kruschke, T.

    2016-12-01

    Although only ca. 12% of the global insured losses of natural disasters occurred in Asia, there are two major reasons to be concerned about risks in Asia: a) The fraction of loss events was substantial higher with 39% of which 94% were due to atmospheric processes; b) Asia and especially China, is undergoing quick transitions and especially the insurance market is rapidly growing. In order to allow for the estimation of potential future (loss) impacts in East-Asia, in this study we further developed and applied a feature tracking system based on extreme wind speed occurrences to tropical cyclones, which was originally developed for extra-tropical cyclones (Leckebusch et al., 2008). In principle, wind fields will be identified and tracked once a coherent exceedance of local percentile thresholds is identified. The focus on severe wind impact will allow an objective link between the strength of a cyclone and its potential damages over land. The wind tracking is developed in such a way to be applicable also to course-gridded AOGCM simulation. In the presented configuration the wind tracking algorithm is applied to the Japanese reanalysis (JRA55) and TC Identification is based on 850hPa wind speeds (6h resolution) from 1979 to 2014 over the Western North Pacific region. For validation the IBTrACS Best Track archive version v03r8 is used. Out of all 904 observed tracks, about 62% can be matched to at least one windstorm event identified in JRA55. It is found that the relative amount of matched best tracks increases with the maximum intensity. Thus, a positive matching (hit rate) of above 98% for Violent Typhoons (VTY), above 90% for Very Strong Typhoons (VSTY), about 75% for Typhoons (TY), and still some 50% for less intense TCs (TD, TS, STS) is found. This result is extremely encouraging to apply this technique to AOGCM outputs and to derive information about affected regions and intensity-frequency distributions potentially changed under future climate conditions.

  18. Ultraviolet radiation modelling from ground-based and satellite measurements on Reunion Island, southern tropics

    Directory of Open Access Journals (Sweden)

    K. Lamy

    2018-01-01

    Full Text Available Surface ultraviolet radiation (SUR is not an increasing concern after the implementation of the Montreal Protocol and the recovery of the ozone layer Morgenstern et al.(2008. However, large uncertainties remain in the prediction of future changes of SUR Bais et al.(2015. Several studies pointed out that UV-B impacts the biosphere Erickson et al.(2015, especially the aquatic system, which plays a central part in the biogeochemical cycle Hader et al.(2007. It can affect phytoplankton productivity Smith and Cullen(1995. This influence can result in either positive or negative feedback on climate (Zepp et al., 2007. Global circulation model simulations predict an acceleration of the Brewer-Dobson circulation over the next century (Butchart, 2014, which would lead to a decrease in ozone levels in the tropics and an enhancement at higher latitudes (Hegglin and Shepherd, 2009. Reunion Island is located in the tropics (21° S, 55° E, in a part of the world where the amount of ozone in the ozone column is naturally low. In addition, this island is mountainous and the marine atmosphere is often clean with low aerosol concentrations. Thus, measurements show much higher SUR than at other sites at the same latitude or at midlatitudes. Ground-based measurements of SUR have been taken on Reunion Island by a Bentham DTMc300 spectroradiometer since 2009. This instrument is affiliated with the Network for the Detection of Atmospheric Composition Change (NDACC. In order to quantify the future evolution of SUR in the tropics, it is necessary to validate a model against present observations. This study is designed to be a preliminary parametric and sensitivity study of SUR modelling in the tropics. We developed a local parameterisation using the Tropospheric Ultraviolet and Visible Model (TUV; Madronich, 1993 and compared the output of TUV to multiple years of Bentham spectral measurements. This comparison started in early 2009 and continued until 2016

  19. Ultraviolet radiation modelling from ground-based and satellite measurements on Reunion Island, southern tropics

    Science.gov (United States)

    Lamy, Kévin; Portafaix, Thierry; Brogniez, Colette; Godin-Beekmann, Sophie; Bencherif, Hassan; Morel, Béatrice; Pazmino, Andrea; Metzger, Jean Marc; Auriol, Frédérique; Deroo, Christine; Duflot, Valentin; Goloub, Philippe; Long, Charles N.

    2018-01-01

    Surface ultraviolet radiation (SUR) is not an increasing concern after the implementation of the Montreal Protocol and the recovery of the ozone layer (Morgenstern et al., 2008). However, large uncertainties remain in the prediction of future changes of SUR (Bais et al., 2015). Several studies pointed out that UV-B impacts the biosphere (Erickson et al., 2015), especially the aquatic system, which plays a central part in the biogeochemical cycle (Hader et al., 2007). It can affect phytoplankton productivity (Smith and Cullen, 1995). This influence can result in either positive or negative feedback on climate (Zepp et al., 2007). Global circulation model simulations predict an acceleration of the Brewer-Dobson circulation over the next century (Butchart, 2014), which would lead to a decrease in ozone levels in the tropics and an enhancement at higher latitudes (Hegglin and Shepherd, 2009). Reunion Island is located in the tropics (21° S, 55° E), in a part of the world where the amount of ozone in the ozone column is naturally low. In addition, this island is mountainous and the marine atmosphere is often clean with low aerosol concentrations. Thus, measurements show much higher SUR than at other sites at the same latitude or at midlatitudes. Ground-based measurements of SUR have been taken on Reunion Island by a Bentham DTMc300 spectroradiometer since 2009. This instrument is affiliated with the Network for the Detection of Atmospheric Composition Change (NDACC). In order to quantify the future evolution of SUR in the tropics, it is necessary to validate a model against present observations. This study is designed to be a preliminary parametric and sensitivity study of SUR modelling in the tropics. We developed a local parameterisation using the Tropospheric Ultraviolet and Visible Model (TUV; Madronich, 1993) and compared the output of TUV to multiple years of Bentham spectral measurements. This comparison started in early 2009 and continued until 2016. Only

  20. 20 Years of Total and Tropical Ozone Time Series Based on European Satellite Observations

    Science.gov (United States)

    Loyola, D. G.; Heue, K. P.; Coldewey-Egbers, M.

    2016-12-01

    Ozone is an important trace gas in the atmosphere, while the stratospheric ozone layer protects the earth surface from the incident UV radiation, the tropospheric ozone acts as green house gas and causes health damages as well as crop loss. The total ozone column is dominated by the stratospheric column, the tropospheric columns only contributes about 10% to the total column.The ozone column data from the European satellite instruments GOME, SCIAMACHY, OMI, GOME-2A and GOME-2B are available within the ESA Climate Change Initiative project with a high degree of inter-sensor consistency. The tropospheric ozone columns are based on the convective cloud differential algorithm. The datasets encompass a period of more than 20 years between 1995 and 2015, for the trend analysis the data sets were harmonized relative to one of the instruments. For the tropics we found an increase in the tropospheric ozone column of 0.75 ± 0.12 DU decade^{-1} with local variations between 1.8 and -0.8. The largest trends were observed over southern Africa and the Atlantic Ocean. A seasonal trend analysis led to the assumption that the increase is caused by additional forest fires.The trend for the total column was not that certain, based on model predicted trend data and the measurement uncertainty we estimated that another 10 to 15 years of observations will be required to observe a statistical significant trend. In the mid latitudes the trends are currently hidden in the large variability and for the tropics the modelled trends are low. Also the possibility of diverging trends at different altitudes must be considered; an increase in the tropospheric ozone might be accompanied by decreasing stratospheric ozone.The European satellite data record will be extended over the next two decades with the atmospheric satellite missions Sentinel 5 Precursor (launch end of 2016), Sentinel 4 and Sentinel 5.

  1. Stand-scale soil respiration estimates based on chamber methods in a Bornean tropical rainforest

    Science.gov (United States)

    Kume, T.; Katayama, A.; Komatsu, H.; Ohashi, M.; Nakagawa, M.; Yamashita, M.; Otsuki, K.; Suzuki, M.; Kumagai, T.

    2009-12-01

    This study was undertaken to estimate stand-scale soil respiration in an aseasonal tropical rainforest on Borneo Island. To this aim, we identified critical and practical factors explaining spatial variations in soil respiration based on the soil respiration measurements conducted at 25 points in a 40 × 40 m subplot of a 4 ha study plot for five years in relation to soil, root, and forest structural factors. Consequently, we found significant positive correlation between the soil respiration and forest structural parameters. The most important factor was the mean DBH within 6 m of the measurement points, which had a significant linear relationship with soil respiration. Using the derived linear regression and an inventory dataset, we estimated the 4 ha-scale soil respiration. The 4 ha-scale estimation (6.0 μmol m-2 s-1) was nearly identical to the subplot scale measurements (5.7 μmol m-2 s-1), which were roughly comparable to the nocturnal CO2 fluxes calculated using the eddy covariance technique. To confirm the spatial representativeness of soil respiration estimates in the subplot, we performed variogram analysis. Semivariance of DBH(6) in the 4 ha plot showed that there was autocorrelation within the separation distance of about 20 m, and that the spatial dependence was unclear at a separation distance of greater than 20 m. This ascertained that the 40 × 40 m subplot could represent the whole forest structure in the 4 ha plot. In addition, we discuss characteristics of the stand-scale soil respiration at this site by comparing with those of other forests reported in previous literature in terms of the soil C balance. Soil respiration at our site was noticeably greater, relative to the incident litterfall amount, than soil respiration in other tropical and temperate forests probably owing to the larger total belowground C allocation by emergent trees. Overall, this study suggests the arrangement of emergent trees and their bellow ground C allocation could be

  2. Monitoring tropical forest dynamics using Landsat time series and community-based data

    NARCIS (Netherlands)

    DeVries, B.R.

    2015-01-01

    Tropical forests cover a significant portion of the earth's surface and provide a range of

    ecosystem services, but are under increasing threat due to human activities. Deforestation

    and forest degradation in the tropics are responsible for a large share of global CO2

  3. The effectiveness of market-based conservation in the tropics: forest certification in Ecuador and Bolivia.

    Science.gov (United States)

    Ebeling, Johannes; Yasué, Maï

    2009-02-01

    During the last decade, forest certification has gained momentum as a market-based conservation strategy in tropical forest countries. Certification has been promoted to enhance forest management in countries where governance capacities are insufficient to adequately manage natural resources and enforce pertinent regulations, given that certification relies largely on non-governmental organisations and private businesses. However, at present there are few tropical countries with large areas of certified forests. In this study, we conducted semi-structured stakeholder interviews in Ecuador and Bolivia to identify key framework conditions that influence the costs and benefits for companies to switch from conventional to certified forestry operations. Bolivia has a much greater relative area under certified forest management than Ecuador and also significantly more certified producers. The difference in the success of certification between both countries is particularly notable because Bolivia is a poorer country with more widespread corruption, and is landlocked with less access to export routes. Despite these factors, several characteristics of the Bolivian forest industry contribute to lower additional costs of certified forest management compared to Ecuador. Bolivia has stronger government enforcement of forestry regulations a fact that increases the cost of illegal logging, management units are larger, and vertical integration in the process chain from timber extraction to markets is higher. Moreover, forestry laws in Bolivia are highly compatible with certification requirements, and the government provides significant tax benefits to certified producers. Results from this study suggest that certification can be successful in countries where governments have limited governance capacity. However, the economic incentives for certification do not only arise from favourable market conditions. Certification is likely to be more successful where governments enforce

  4. Carbon sequestration in pastures, silvo-pastoral systems and forests in four regions of the latin American Tropics

    NARCIS (Netherlands)

    Amezquita, M.C.; Ibrahim, M.; Llanderal, T.; Buurman, P.; Amezquita, E.

    2005-01-01

    Tropical America (TA) holds 8% of the world's population, 11% of the world's continental area, 23% and 22%, respectively, of the world's forest and water resources, and 13% of the world's pasture and agro-pastoral land, this representing 77% of TA's agricultural land. Recent interest in carbon

  5. Airborne relay-based regional positioning system.

    Science.gov (United States)

    Lee, Kyuman; Noh, Hongjun; Lim, Jaesung

    2015-05-28

    Ground-based pseudolite systems have some limitations, such as low vertical accuracy, multipath effects and near-far problems. These problems are not significant in airborne-based pseudolite systems. However, the monitoring of pseudolite positions is required because of the mobility of the platforms on which the pseudolites are mounted, and this causes performance degradation. To address these pseudolite system limitations, we propose an airborne relay-based regional positioning system that consists of a master station, reference stations, airborne relays and a user. In the proposed system, navigation signals are generated from the reference stations located on the ground and are relayed via the airborne relays. Unlike in conventional airborne-based systems, the user in the proposed system sequentially estimates both the locations of airborne relays and his/her own position. Therefore, a delay due to monitoring does not occur, and the accuracy is not affected by the movement of airborne relays. We conducted several simulations to evaluate the performance of the proposed system. Based on the simulation results, we demonstrated that the proposed system guarantees a higher accuracy than airborne-based pseudolite systems, and it is feasible despite the existence of clock offsets among reference stations.

  6. Global contrast based salient region detection

    KAUST Repository

    Cheng, Ming-Ming

    2011-08-25

    Reliable estimation of visual saliency allows appropriate processing of images without prior knowledge of their contents, and thus remains an important step in many computer vision tasks including image segmentation, object recognition, and adaptive compression. We propose a regional contrast based saliency extraction algorithm, which simultaneously evaluates global contrast differences and spatial coherence. The proposed algorithm is simple, efficient, and yields full resolution saliency maps. Our algorithm consistently outperformed existing saliency detection methods, yielding higher precision and better recall rates, when evaluated using one of the largest publicly available data sets. We also demonstrate how the extracted saliency map can be used to create high quality segmentation masks for subsequent image processing.

  7. Global contrast based salient region detection

    KAUST Repository

    Cheng, Ming-Ming; Zhang, Guo-Xin; Mitra, Niloy J.; Huang, Xiaolei; Hu, Shi-Min

    2011-01-01

    Reliable estimation of visual saliency allows appropriate processing of images without prior knowledge of their contents, and thus remains an important step in many computer vision tasks including image segmentation, object recognition, and adaptive compression. We propose a regional contrast based saliency extraction algorithm, which simultaneously evaluates global contrast differences and spatial coherence. The proposed algorithm is simple, efficient, and yields full resolution saliency maps. Our algorithm consistently outperformed existing saliency detection methods, yielding higher precision and better recall rates, when evaluated using one of the largest publicly available data sets. We also demonstrate how the extracted saliency map can be used to create high quality segmentation masks for subsequent image processing.

  8. Community-based management induces rapid recovery of a high-value tropical freshwater fishery

    Science.gov (United States)

    Campos-Silva, João Vitor; Peres, Carlos A.

    2016-10-01

    Tropical wetlands are highly threatened socio-ecological systems, where local communities rely heavily on aquatic animal protein, such as fish, to meet food security. Here, we quantify how a ‘win-win’ community-based resource management program induced stock recovery of the world’s largest scaled freshwater fish (Arapaima gigas), providing both food and income. We analyzed stock assessment data over eight years and examined the effects of protected areas, community-based management, and landscape and limnological variables across 83 oxbow lakes monitored along a ~500-km section of the Juruá River of Western Brazilian Amazonia. Patterns of community management explained 71.8% of the variation in arapaima population sizes. Annual population counts showed that protected lakes on average contained 304.8 (±332.5) arapaimas, compared to only 9.2 (±9.8) in open-access lakes. Protected lakes have become analogous to a high-interest savings account, ensuring an average annual revenue of US$10,601 per community and US$1046.6 per household, greatly improving socioeconomic welfare. Arapaima management is a superb window of opportunity in harmonizing the co-delivery of sustainable resource management and poverty alleviation. We show that arapaima management deserves greater attention from policy makers across Amazonian countries, and highlight the need to include local stakeholders in conservation planning of Amazonian floodplains.

  9. Land-use change in oil palm dominated tropical landscapes-An agent-based model to explore ecological and socio-economic trade-offs.

    Science.gov (United States)

    Dislich, Claudia; Hettig, Elisabeth; Salecker, Jan; Heinonen, Johannes; Lay, Jann; Meyer, Katrin M; Wiegand, Kerstin; Tarigan, Suria

    2018-01-01

    Land-use changes have dramatically transformed tropical landscapes. We describe an ecological-economic land-use change model as an integrated, exploratory tool used to analyze how tropical land-use change affects ecological and socio-economic functions. The model analysis seeks to determine what kind of landscape mosaic can improve the ensemble of ecosystem functioning, biodiversity, and economic benefit based on the synergies and trade-offs that we have to account for. More specifically, (1) how do specific ecosystem functions, such as carbon storage, and economic functions, such as household consumption, relate to each other? (2) How do external factors, such as the output prices of crops, affect these relationships? (3) How do these relationships change when production inefficiency differs between smallholder farmers and learning is incorporated? We initialize the ecological-economic model with artificially generated land-use maps parameterized to our study region. The economic sub-model simulates smallholder land-use management decisions based on a profit maximization assumption. Each household determines factor inputs for all household fields and decides on land-use change based on available wealth. The ecological sub-model includes a simple account of carbon sequestration in above-ground and below-ground vegetation. We demonstrate model capabilities with results on household consumption and carbon sequestration from different output price and farming efficiency scenarios. The overall results reveal complex interactions between the economic and ecological spheres. For instance, model scenarios with heterogeneous crop-specific household productivity reveal a comparatively high inertia of land-use change. Our model analysis even shows such an increased temporal stability in landscape composition and carbon stocks of the agricultural area under dynamic price trends. These findings underline the utility of ecological-economic models, such as ours, to act as

  10. Comparative study of solar cooling systems with building-integrated solar collectors for use in sub-tropical regions like Hong Kong

    International Nuclear Information System (INIS)

    Fong, K.F.; Lee, C.K.; Chow, T.T.

    2012-01-01

    Highlights: ► Performance of building-integrated solar collectors analyzed. ► Comparisons made with solar collectors installed on roof. ► Use of building-integrated solar collectors increased the total primary consumption. ► Reduction in the building load could not compensate drop in solar collector output. ► Building-integrated solar collectors only used when roof space insufficient. -- Abstract: The performance of solar cooling systems with building-integrated (BI) solar collectors was simulated and the results compared with those having the solar collectors installed conventionally on the roof based on the weather data in Hong Kong. Two types of solar collectors and the corresponding cooling systems, namely the flat-plate collectors for absorption refrigeration and the PV panels for DC-driven vapour compression refrigeration, were used in the analysis. It was found that in both cases, the adoption of BI solar collectors resulted in a lower solar fraction (SF) and consequently a higher primary energy consumption even though the zone loads were reduced. The reduction in SF was more pronounced in the peak load season when the solar radiation was nearly parallel to the solar collector surfaces during the daytimes, especially for those facing the south direction. Indeed, there were no outputs from the BI flat-plate collectors facing the south direction between May and July. The more severe deterioration in the system performance with the BI flat-plate type collectors made them technically infeasible in terms of the energy-saving potential. It was concluded that the use of BI solar collectors in solar cooling systems should be restricted only to situations where the availability of the roof was limited or insufficient when applied in sub-tropical regions like Hong Kong.

  11. Study of atmospheric scattering and absorbing aerosols at 550 nm over nearby western Indian tropical sites of Thar Desert effected region

    International Nuclear Information System (INIS)

    Vyas, B. M.; Saxenna, Abhishek; Panwar, Chhagan

    2016-01-01

    The first time experimental results based on spaced satellite observations of different kinds of aerosols properties have been described over two different contrast environmental conditions locations in western tropical Indian region specifically first at Jaisalmer (26.90°N, 69.90°E, 220 m above mean sea level (amsl)) located in central Thar dessert vicinity of western Indian site over Indian Thar Desert region and another at Udaipur (24.6° N, 73.7° E, 560 m amsl) site concerning to semi-urban and semi arid place of hilly areas. The daily values of aerosols optical depth absorption at 500nm (AOD abs 500nm), aerosols optical depth extinction at 500nm (AOD ext 500nm) along with aerosols optical depth at 500nmon (AOD 500nm) of eleven year period from Jan., 2004 to Dec., 2014 are basis of primary database of the present investigation. From the synthesis if the above database and the basis of rigorous statistical approach, following some of interesting facts are noted (i) larger annual monthly AOD variation of 0.93 is noted over JSM when compared to observed annual monthly change in AOD cycle, over UDP, of only 0.50 clearly indicating the more impact of desert influence activities about more than double times over JSM than UDP (ii) The higher abundance of absorbing aerosols occurrences about two time higher are seen in JSM in comparison to UDP. It indicates the clear evidence of strong optical absorption properties of useful solar mid visible wavelength at 550nm as the results of presence of more availability of dust aerosols as mineral natural type in pre-monsoon to post-monsoon over JSM which is also more predominant over JSM than the UDP region located far away from desert activity regime (iii) The greater sharing of extinction solar radiation effect on aerosols are more effective in pre-monsoon in UDP in reference to over JSM, where as in case of UDP, the aerosols effect through the scattering mechanism gradually reduce from monsoon to winter months as compared

  12. Study of atmospheric scattering and absorbing aerosols at 550 nm over nearby western Indian tropical sites of Thar Desert effected region

    Energy Technology Data Exchange (ETDEWEB)

    Vyas, B. M., E-mail: bmvyas@yahoo.com; Saxenna, Abhishek; Panwar, Chhagan [Department of Physics, M.L. Sukhadia University, Udaipur-313001 (India)

    2016-05-06

    The first time experimental results based on spaced satellite observations of different kinds of aerosols properties have been described over two different contrast environmental conditions locations in western tropical Indian region specifically first at Jaisalmer (26.90°N, 69.90°E, 220 m above mean sea level (amsl)) located in central Thar dessert vicinity of western Indian site over Indian Thar Desert region and another at Udaipur (24.6° N, 73.7° E, 560 m amsl) site concerning to semi-urban and semi arid place of hilly areas. The daily values of aerosols optical depth absorption at 500nm (AOD abs 500nm), aerosols optical depth extinction at 500nm (AOD ext 500nm) along with aerosols optical depth at 500nmon (AOD 500nm) of eleven year period from Jan., 2004 to Dec., 2014 are basis of primary database of the present investigation. From the synthesis if the above database and the basis of rigorous statistical approach, following some of interesting facts are noted (i) larger annual monthly AOD variation of 0.93 is noted over JSM when compared to observed annual monthly change in AOD cycle, over UDP, of only 0.50 clearly indicating the more impact of desert influence activities about more than double times over JSM than UDP (ii) The higher abundance of absorbing aerosols occurrences about two time higher are seen in JSM in comparison to UDP. It indicates the clear evidence of strong optical absorption properties of useful solar mid visible wavelength at 550nm as the results of presence of more availability of dust aerosols as mineral natural type in pre-monsoon to post-monsoon over JSM which is also more predominant over JSM than the UDP region located far away from desert activity regime (iii) The greater sharing of extinction solar radiation effect on aerosols are more effective in pre-monsoon in UDP in reference to over JSM, where as in case of UDP, the aerosols effect through the scattering mechanism gradually reduce from monsoon to winter months as compared

  13. Species Diversity Distribution Patterns of Chinese Endemic Seed Plants Based on Geographical Regions.

    Science.gov (United States)

    Huang, Jihong; Ma, Keping; Huang, Jianhua

    2017-01-01

    Based on a great number of literatures, we established the database about the Chinese endemic seed plants and analyzed the compositions, growth form, distribution and angiosperm original families of them within three big natural areas and seven natural regions. The results indicate that the above characters of Chinese endemic plants take on relative rule at the different geographical scales. Among the three big natural areas, Eastern Monsoon area has the highest endemic plants richness, whereas Northwest Dryness area is the lowest. For life forms, herbs dominate. In contrast, the proportion of herbs of Eastern Monsoon area is remarkable under other two areas. Correspondingly the proportions of trees and shrubs are substantially higher than other two. For angiosperm original families, the number is the highest in Eastern Monsoon area, and lowest in Northwest Dryness area. On the other hand, among the seven natural regions, the humid and subtropical zone in Central and Southern China has the highest endemic plants richness, whereas the humid, hemi-humid region and temperate zone in Northeast China has the lowest. For life forms, the proportion of herbs tends to decrease from humid, hemi-humid region and temperate zone in Northeast China to humid and tropical zone in Southern China. Comparably, trees, shrubs and vines or lianas increase with the same directions. This fully represents these characters of Chinese endemic plants vary with latitudinal gradients. Furthermore, as to the number of endemic plants belonging to angiosperm original families, the number is the most in humid and subtropical zone in Center and Southern China, and tropical zone in Southern China in the next place. In contrast, the endemic plant of these two regions relatively is richer than that of The Qinghai-Tibet alpine and cold region. All above results sufficiently reflect that the Chinese endemic plants mainly distribute in Eastern Monsoon area, especially humid and subtropical zone in Center

  14. Temporal bird community dynamics are strongly affected by landscape fragmentation in a Central American tropical forest region

    Science.gov (United States)

    Blandón, A.C.; Perelman, S.B.; Ramírez, M.; López, A.; Javier, O.; Robbins, Chandler S.

    2016-01-01

    Habitat loss and fragmentation are considered the main causes of species extinctions, particularly in tropical ecosystems. The objective of this work was to evaluate the temporal dynamics of tropical bird communities in landscapes with different levels of fragmentation in eastern Guatemala. We evaluated five bird community dynamic parameters for forest specialists and generalists: (1) species extinction, (2) species turnover, (3) number of colonizing species, (4) relative species richness, and (5) a homogeneity index. For each of 24 landscapes, community dynamic parameters were estimated from bird point count data, for the 1998–1999 and 2008–2009 periods, accounting for species’ detection probability. Forest specialists had higher extinction rates and a smaller number of colonizing species in landscapes with higher fragmentation, thus having lower species richness in both time periods. Alternatively, forest generalists elicited a completely different pattern, showing a curvilinear association to forest fragmentation for most parameters. Thus, greater community dynamism for forest generalists was shown in landscapes with intermediate levels of fragmentation. Our study supports general theory regarding the expected negative effects of habitat loss and fragmentation on the temporal dynamics of biotic communities, particularly for forest specialists, providing strong evidence from understudied tropical bird communities.

  15. Diferencias regionales y Síndrome Pulmonar por Hantavirus (enfermedad emergente y tropical en Argentina Regional differences and Hantavirus pulmonary syndrome (an emerging and tropical disease in Argentina

    Directory of Open Access Journals (Sweden)

    Sergio Sosa-Estani

    2001-01-01

    Full Text Available Se describen algunos factores que habrían favorecido a caracterizar la expresión del Síndrome Pulmonar por Hantavirus en Argentina. Estos factores muestran diversos orígenes que van desde los procesos de ocupación del espacio y de producción, la estructura laboral, el patrón de migración humana, la etnia, la dinámica de reservorios y su relación con los tipos de virus, y el comportamiento del hombre. Estos factores se expresan en tres marcos ecológicos asociados a diferentes regiones geográficas de Argentina: 1 Noroeste, 2 Central (Pampa húmeda y 3 Sur Andina. Este complejo escenario obliga a abordar con la misma complejidad las investigaciones, para identificar determinantes primarios, biológicos, sociales y ambientales, causales de salud o enfermedad en su estrecha interacción y no individualmente. Este abordaje permitirá diseñar estrategias apropiadas para mejorar las condiciones de salud. Las mismas deberían ser diseñadas y transferidas por equipos transdisciplinarios de investigación, donde la participación de la comunidad desde las primeras etapas de desarrollo es esencial para la sustentabilidad de la estrategia.Factors related to the characteristics of Hantavirus pulmonary syndrome in Argentina are described. Factors from different scientific fields converge to form the syndrome's analytical framework. Some of these factors are the history of spatial occupation, work and production structures, human migration patterns, ethnic composition, reservoir dynamics and its relationship to the different circulating viruses, and human behavior. Furthermore, the multiple factors are expressed in three ecological frameworks, associated with three different geographical regions of Argentina: 1 Northwest; 2 Central ("wet Pampa"; and 3 South Andean. In order to understand the actual causality of health or disease as an interaction of many factors, research on the primary biological, social, and environmental determinants of

  16. Tropical Rainforests.

    Science.gov (United States)

    Nigh, Ronald B.; Nations, James D.

    1980-01-01

    Presented is a summary of scientific knowledge about the rainforest environment, a tropical ecosystem in danger of extermination. Topics include the current state of tropical rainforests, the causes of rainforest destruction, and alternatives of rainforest destruction. (BT)

  17. Lightning and 85-GHz MCSs in the Global Tropics

    Science.gov (United States)

    Toracinta, E. Richard; Zipser, E. J.

    1999-01-01

    Numerous observations of tropical convection show that tropical continental mesoscale convective systems (MCSs) are much more prolific lightning producers than their oceanic counterparts. Satellite-based climatologies using 85-GHz passive microwave ice-scattering signatures from the Special Sensor Microwave/Imager (SSM/I) indicate that MCSs of various size and intensity are found throughout the global tropics. In contrast, global lightning distributions show a strong land bias with an order of magnitude difference between land and ocean lightning. This is somewhat puzzling, since 85-GHz ice-scattering and the charge separation processes that lead to lightning are both thought to depend upon the existence of large graupel particles. The fact that low 85-GHz brightness temperatures are observed in tropical oceanic MCSs containing virtually no lightning leads to the postulate that tropical oceanic and tropical continental MCSs have fundamentally different hydrometeor profiles through the mixed phase region of the cloud (0 C Lightning Imaging Sensor (LIS), and the first space-borne radar, facilitates high-resolution case studies of MCS structure throughout the global tropics. An important precursor, however, is to better understand the distribution of MCSs and lightning in the tropics. With that objective in mind, this research undertakes a systematic comparison of 85-GHz-defined MCSs and lightning over the global tropics for a full year, as an initial step toward quantifying differences between land and ocean convective systems.

  18. Constructing regional advantage: platform policies based on related variety and differentiated knowledge bases.

    NARCIS (Netherlands)

    Asheim, B.T.; Boschma, R.A.; Cooke, P.

    2011-01-01

    Constructing regional advantage: platform policies based on related variety and differentiated knowledge bases, Regional Studies. This paper presents a regional innovation policy model based on the idea of constructing regional advantage. This policy model brings together concepts like related

  19. Environmental conditioning on uranium surface distribution in the tropical region; Condicionantes ambientais sobre a distribuicao superficial de uranio numa regiao de climatologia tropical

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Heitor Evangelista da; Licinio, Marcus V.S.; Miranda, Marcio R. [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Lab. de Ciencias Radiologicas

    2001-07-01

    Based on a high resolution aerogammaspectrometer survey over the State of Rio de Janeiro, it is presented an associative study of equivalent uranium concentration and environmental parameters. The aspects considered in this study included geological domains like Sandys, Gnaisses, Granites, Xists; soils domains like Organic and Alluvial ones, Litolic, Glei, Podzolic, Red-yellow, Latossolo, Planossolo, Red bruizem, Cambissolo, Hidromorphic Podzol, Yellow latossolo; geomorphology (Coast Plains and River Accumulation Land, Coast Tabulators, Pomba-Muriae Rivers Spread Depression, Northern Mantiqueira, main Hills and Coastal Rock Massifs, Steep slopes and Reverses of Serra do Mar Mountain Range ,Serra dos Orgaos Mountain Range and Bocaina Tablelands), Paraiba do Sul Crests Alignment, Medium Paraiba do Sul Depression); influence of mean annual rain intensity and hydrographical categories were also evaluated. Geoprocessing of each environmental data base at the same cartographical base of uranium surface distribution was the basic methodology employed. (author)

  20. Remote Sensing Based Spatial Statistics to Document Tropical Rainforest Transition Pathways

    Directory of Open Access Journals (Sweden)

    Abduwasit Ghulam

    2015-05-01

    Full Text Available In this paper, grid cell based spatial statistics were used to quantify the drivers of land-cover and land-use change (LCLUC and habitat degradation in a tropical rainforest in Madagascar. First, a spectral database of various land-cover and land-use information was compiled using multi-year field campaign data and photointerpretation of satellite images. Next, residential areas were extracted from IKONOS-2 and GeoEye-1 images using object oriented feature extraction (OBIA. Then, Landsat Thematic Mapper (TM and Enhanced Thematic Mapper Plus (ETM+ data were used to generate land-cover and land-use maps from 1990 to 2011, and LCLUC maps were developed with decadal intervals and converted to 100 m vector grid cells. Finally, the causal associations between LCLUC were quantified using ordinary least square regression analysis and Moran’s I, and a forest disturbance index derived from the time series Landsat data were used to further confirm LCLUC drivers. The results showed that (1 local spatial statistical approaches were most effective at quantifying the drivers of LCLUC, and (2 the combined threats of habitat degradation in and around the reserve and increasing encroachment of invasive plant species lead to the expansion of shrubland and mixed forest within the former primary forest, which was echoed by the forest disturbance index derived from the Landsat data.

  1. CpDNA-based species identification and phylogeography: application to African tropical tree species.

    Science.gov (United States)

    Duminil, J; Heuertz, M; Doucet, J-L; Bourland, N; Cruaud, C; Gavory, F; Doumenge, C; Navascués, M; Hardy, O J

    2010-12-01

    Despite the importance of the African tropical rainforests as a hotspot of biodiversity, their history and the processes that have structured their biodiversity are understood poorly. With respect to past demographic processes, new insights can be gained through characterizing the distribution of genetic diversity. However, few studies of this type have been conducted in Central Africa, where the identification of species in the field can be difficult. We examine here the distribution of chloroplast DNA (cpDNA) diversity in Lower Guinea in two tree species that are difficult to distinguish, Erythrophleum ivorense and Erythrophleum suaveolens (Fabaceae). By using a blind-sampling approach and comparing molecular and morphological markers, we first identified retrospectively all sampled individuals and determined the limits of the distribution of each species. We then performed a phylogeographic study using the same genetic data set. The two species displayed essentially parapatric distributions that were correlated well with the rainfall gradient, which indicated different ecological requirements. In addition, a phylogeographic structure was found for E. suaveolens and, for both species, substantially higher levels of diversity and allelic endemism were observed in the south (Gabon) than in the north (Cameroon) of the Lower Guinea region. This finding indicated different histories of population demographics for the two species, which might reflect different responses to Quaternary climate changes. We suggest that a recent period of forest perturbation, which might have been caused by humans, favoured the spread of these two species and that their poor recruitment at present results from natural succession in their forest formations. © 2010 Blackwell Publishing Ltd.

  2. Role of sea surface temperature anomalies in the tropical Indo-Pacific region in the northeast Asia severe drought in summer 2014: month-to-month perspective

    Science.gov (United States)

    Xu, Zhiqing; Fan, Ke; Wang, HuiJun

    2017-09-01

    The severe drought over northeast Asia in summer 2014 and the contribution to it by sea surface temperature (SST) anomalies in the tropical Indo-Pacific region were investigated from the month-to-month perspective. The severe drought was accompanied by weak lower-level summer monsoon flow and featured an obvious northward movement during summer. The mid-latitude Asian summer (MAS) pattern and East Asia/Pacific teleconnection (EAP) pattern, induced by the Indian summer monsoon (ISM) and western North Pacific summer monsoon (WNPSM) rainfall anomalies respectively, were two main bridges between the SST anomalies in the tropical Indo-Pacific region and the severe drought. Warming in the Arabian Sea induced reduced rainfall over northeast India and then triggered a negative MAS pattern favoring the severe drought in June 2014. In July 2014, warming in the tropical western North Pacific led to a strong WNPSM and increased rainfall over the Philippine Sea, triggering a positive EAP pattern. The equatorial eastern Pacific and local warming resulted in increased rainfall over the off-equatorial western Pacific and triggered an EAP-like pattern. The EAP pattern and EAP-like pattern contributed to the severe drought in July 2014. A negative Indian Ocean dipole induced an anomalous meridional circulation, and warming in the equatorial eastern Pacific induced an anomalous zonal circulation, in August 2014. The two anomalous cells led to a weak ISM and WNPSM, triggering the negative MAS and EAP patterns responsible for the severe drought. Two possible reasons for the northward movement of the drought were also proposed.

  3. Polarimetric SAR Interferometry based modeling for tree height and aboveground biomass retrieval in a tropical deciduous forest

    Science.gov (United States)

    Kumar, Shashi; Khati, Unmesh G.; Chandola, Shreya; Agrawal, Shefali; Kushwaha, Satya P. S.

    2017-08-01

    The regulation of the carbon cycle is a critical ecosystem service provided by forests globally. It is, therefore, necessary to have robust techniques for speedy assessment of forest biophysical parameters at the landscape level. It is arduous and time taking to monitor the status of vast forest landscapes using traditional field methods. Remote sensing and GIS techniques are efficient tools that can monitor the health of forests regularly. Biomass estimation is a key parameter in the assessment of forest health. Polarimetric SAR (PolSAR) remote sensing has already shown its potential for forest biophysical parameter retrieval. The current research work focuses on the retrieval of forest biophysical parameters of tropical deciduous forest, using fully polarimetric spaceborne C-band data with Polarimetric SAR Interferometry (PolInSAR) techniques. PolSAR based Interferometric Water Cloud Model (IWCM) has been used to estimate aboveground biomass (AGB). Input parameters to the IWCM have been extracted from the decomposition modeling of SAR data as well as PolInSAR coherence estimation. The technique of forest tree height retrieval utilized PolInSAR coherence based modeling approach. Two techniques - Coherence Amplitude Inversion (CAI) and Three Stage Inversion (TSI) - for forest height estimation are discussed, compared and validated. These techniques allow estimation of forest stand height and true ground topography. The accuracy of the forest height estimated is assessed using ground-based measurements. PolInSAR based forest height models showed enervation in the identification of forest vegetation and as a result height values were obtained in river channels and plain areas. Overestimation in forest height was also noticed at several patches of the forest. To overcome this problem, coherence and backscatter based threshold technique is introduced for forest area identification and accurate height estimation in non-forested regions. IWCM based modeling for forest

  4. Simulation of tropical cyclone activity over the western North Pacific based on CMIP5 models

    Science.gov (United States)

    Shen, Haibo; Zhou, Weican; Zhao, Haikun

    2017-09-01

    Based on the Coupled Model Inter-comparison Project 5 (CMIP5) models, the tropical cyclone (TC) activity in the summers of 1965-2005 over the western North Pacific (WNP) is simulated by a TC dynamically downscaling system. In consideration of diversity among climate models, Bayesian model averaging (BMA) and equal-weighed model averaging (EMA) methods are applied to produce the ensemble large-scale environmental factors of the CMIP5 model outputs. The environmental factors generated by BMA and EMA methods are compared, as well as the corresponding TC simulations by the downscaling system. Results indicate that BMA method shows a significant advantage over the EMA. In addition, impacts of model selections on BMA method are examined. To each factor, ten models with better performance are selected from 30 CMIP5 models and then conduct BMA, respectively. As a consequence, the ensemble environmental factors and simulated TC activity are similar with the results from the 30 models' BMA, which verifies the BMA method can afford corresponding weight for each model in the ensemble based on the model's predictive skill. Thereby, the existence of poor performance models will not particularly affect the BMA effectiveness and the ensemble outcomes are improved. Finally, based upon the BMA method and downscaling system, we analyze the sensitivity of TC activity to three important environmental factors, i.e., sea surface temperature (SST), large-scale steering flow, and vertical wind shear. Among three factors, SST and large-scale steering flow greatly affect TC tracks, while average intensity distribution is sensitive to all three environmental factors. Moreover, SST and vertical wind shear jointly play a critical role in the inter-annual variability of TC lifetime maximum intensity and frequency of intense TCs.

  5. Multi region based image retrieval system

    Indian Academy of Sciences (India)

    data mining, information theory, statistics and psychology. ∗ .... ground complication and independent of image size and orientation (Zhang 2007). ..... Figure 2. Significant regions: (a) the input image, (b) the primary significant region, (c) the ...

  6. On exploiting wavelet bases in statistical region-based segmentation

    DEFF Research Database (Denmark)

    Stegmann, Mikkel Bille; Forchhammer, Søren

    2002-01-01

    Statistical region-based segmentation methods such as the Active Appearance Models establish dense correspondences by modelling variation of shape and pixel intensities in low-resolution 2D images. Unfortunately, for high-resolution 2D and 3D images, this approach is rendered infeasible due to ex...... 9-7 wavelet on cardiac MRIs and human faces show that the segmentation accuracy is minimally degraded at compression ratios of 1:10 and 1:20, respectively....

  7. Prevalence of bovine subclinical mastitis, its etiology and diagnosis of antibiotic resistance of dairy farms in four municipalities of a tropical region of Mexico.

    Science.gov (United States)

    Olivares-Pérez, Jaime; Kholif, Ahmed Eid; Rojas-Hernández, Saul; Elghandour, Mona Mohamed Mohamed Yasseen; Salem, Abdelfattah Zeidan Mohamed; Bastida, Adrian Zaragoza; Velázquez-Reynoso, David; Cipriano-Salazar, Moisés; Camacho-Díaz, Luis Miguel; Alonso-Fresán, María Uxúa; DiLorenzo, Nicolas

    2015-12-01

    A region-wide survey was conducted in the tropical area of Tierra Caliente, State of Guerrero, Mexico to estimate the prevalence of subclinical bovine mastitis (SCM), distribution of mastitis pathogens, and in vitro antimicrobial susceptibility of different mastitis pathogens in dairy farms. In total, 1036 quarter milk samples were obtained from 259 cows at 87 different dairy farms. Collected quarter milk samples were submitted for California Mastitis Test (CMT), bacteriological examination, and testing for antimicrobial susceptibility. Overall prevalence of SCM in the studied area was 20.5 %. Prevalence in the different regions was as follows: 28 % in Arcelia municipality, 21 % in Tlalchapa municipality, 19.4 % in Pungarabato municipality, and 14.3 % in Finch Cutzamala municipality. Of all positive isolates, 97.5 % were Gram-negative bacteria. Moreover, of all positive isolates, 37.5 % were Proteus vulgaris, 25 % Salmonella spp., 12.5 % Enterobacter aerogenes, and 10 % Escherichia coli. Klebsiella pneumonia and E. coli were sensitive for netilmicin antimicrobial. However, E. coli was sensitive for pefloxacin and gentamicin with a sensitivity for pefloxacin for E. aerogenes, while Staphylococci were sensitive for gentamicin and dicloxacillin. It could be concluded that practices such as the implementation of mastitis control programs, improved milking hygiene together with an intramammary treatment with netilmicin, pefloxacin, and gentamicin antimicrobials should be considered for mastitis prevention in the study area of Tierra Caliente, in the tropical area of Guerrero, Mexico.

  8. Trade-offs between ecosystem services and alternative pathways toward sustainability in a tropical dry forest region

    Directory of Open Access Journals (Sweden)

    Francisco Mora

    2016-12-01

    Full Text Available The design of strategies aimed at sustainable resource management requires an understanding of the trade-offs between the ecosystem services at stake, to determine appropriate ways in which to navigate them. We assess trade-offs between forage production for cattle ranching and the maintenance of carbon stocks or tree diversity in a Mexican tropical dry forest. Trade-offs between pairs of services were assessed by identifying their efficiency frontiers at both site and landscape scales. We also estimated service outcomes under current and hypothetical land-management conditions. We found stark trade-offs between fodder and carbon stocks and between fodder and tree species richness at the site scale. At the landscape scale, the efficiency frontier was concave, with a much less pronounced trade-off in the fodder-species richness case. Our estimates of current service supply levels showed a reduction of 18-21% for C stock and 41-43% for fodder biomass, relative to the maximum feasible values along the efficiency frontier. Choice of the optimum management strategy to reduce such inefficiency depended on deforestation level: secondary forest regeneration was most suitable when deforestation is low, whereas increased fodder productivity in the pastures is best when deforestation is high. Pasture enrichment with forage trees and secondary forest growth are potential management alternatives for achieving sustainability given the range of enabling ecological factors and to balance ecological and social sustainability given the requirements and preferences of local stakeholders. Given that analogous trade-offs are found across the tropics, this work contributes to reconciling tropical forest maintenance and its use for sustainable rural livelihoods.

  9. Tropical Glaciers

    Science.gov (United States)

    Fountain, Andrew

    The term "tropical glacier" calls to mind balmy nights and palm trees on one hand and cold, blue ice on the other. Certainly author Gabriel Garcia Marqez exploited this contrast in One Hundred Years of Solitude. We know that tropical fish live in warm, Sun-kissed waters and tropical plants provide lush, dense foliage populated by colorful tropical birds. So how do tropical glaciers fit into this scene? Like glaciers everywhere, tropical glaciers form where mass accumulation—usually winter snow—exceeds mass loss, which is generally summer melt. Thus, tropical glaciers exist at high elevations where precipitation can occur as snowfall exceeds melt and sublimation losses, such as the Rwenzori Mountains in east Africa and the Maoke Range of Irian Jaya.

  10. An eddy-permitting, dynamically consistent adjoint-based assimilation system for the tropical Pacific: Hindcast experiments in 2000

    KAUST Repository

    Hoteit, Ibrahim

    2010-03-02

    An eddy-permitting adjoint-based assimilation system has been implemented to estimate the state of the tropical Pacific Ocean. The system uses the Massachusetts Institute of Technology\\'s general circulation model and its adjoint. The adjoint method is used to adjust the model to observations by controlling the initial temperature and salinity; temperature, salinity, and horizontal velocities at the open boundaries; and surface fluxes of momentum, heat, and freshwater. The model is constrained with most of the available data sets in the tropical Pacific, including Tropical Atmosphere and Ocean, ARGO, expendable bathythermograph, and satellite SST and sea surface height data, and climatologies. Results of hindcast experiments in 2000 suggest that the iterated adjoint-based descent is able to significantly improve the model consistency with the multivariate data sets, providing a dynamically consistent realization of the tropical Pacific circulation that generally matches the observations to within specified errors. The estimated model state is evaluated both by comparisons with observations and by checking the controls, the momentum balances, and the representation of small-scale features that were not well sampled by the observations used in the assimilation. As part of these checks, the estimated controls are smoothed and applied in independent model runs to check that small changes in the controls do not greatly change the model hindcast. This is a simple ensemble-based uncertainty analysis. In addition, the original and smoothed controls are applied to a version of the model with doubled horizontal resolution resulting in a broadly similar “downscaled” hindcast, showing that the adjustments are not tuned to a single configuration (meaning resolution, topography, and parameter settings). The time-evolving model state and the adjusted controls should be useful for analysis or to supply the forcing, initial, and boundary conditions for runs of other models.

  11. Compendium of NASA Data Base for the Global Tropospheric Experiment's Pacific Exploratory Mission - Tropics B (PEM-Tropics B). Volume 2; P-3B

    Science.gov (United States)

    Scott, A. Donald, Jr.; Kleb, Mary M.; Raper, James L.

    2000-01-01

    This report provides a compendium of NASA aircraft data that are available from NASA's Global Tropospheric Experiment's (GTE) Pacific Exploratory Mission-Tropics B (PEM-Tropics B) conducted in March and April 1999. PEM-Tropics B was conducted during the southern-tropical wet season when the influence from biomass burning observed in PEM-Tropics A was minimal. Major deployment sites were Hawaii, Kiritimati (Christmas Island), Tahiti, Fiji, and Easter Island. The broad goals of PEM-Tropics B were to improved understanding of the oxidizing power of the atmosphere and the processes controlling sulfur aerosol formation and to establish baseline values for chemical species that are directly coupled to the oxidizing power and aerosol loading of the troposphere. The purpose of this document is to provide a representation of aircraft data that will be available in archived format via NASA Langley's Distributed Active Archive Center (DAAC) or are available through the GTE Project Office archive. The data format is not intended to support original research/analysis, but to assist the reader in identifying data that are of interest.

  12. Compendium of NASA Data Base for the Global Tropospheric Experiment's Pacific Exploratory Mission-Tropics B (PEM-Tropics B). Volume 1; DC-8

    Science.gov (United States)

    Scott, A. Donald, Jr.; Kleb, Mary M.; Raper, James L.

    2000-01-01

    This report provides a compendium of NASA aircraft data that are available from NASA's Global Tropospheric Experiment's (GTE) Pacific Exploratory Mission-Tropics B (PEM-Tropics B) conducted in March and April 1999. PEM-Tropics B was conducted during the southern-tropical wet season when the influence from biomass burning observed in PEM-Tropics A was minimal. Major deployment sites were Hawaii, Kiritimati (Christmas Island), Tahiti, Fiji, and Easter Island. The broad goals of PEM-Tropics B were to improved understanding of the oxidizing power of the atmosphere and the processes controlling sulfur aerosol formation and to establish baseline values for chemical species that are directly coupled to the oxidizing power and aerosol loading of the troposphere. The purpose of this document is to provide a representation of aircraft data that will be available in archived format via NASA Langley's Distributed Active Archive Center (DAAC) or are available through the GTE Project Office archive. The data format is not intended to support original research/analysis, but to assist the reader in identifying data that are of interest.

  13. Estimates of biomass burning emissions in tropical Asia based on satellite-derived data

    OpenAIRE

    D. Chang; Y. Song

    2009-01-01

    Biomass burning in tropical Asia emits large amounts of trace gases and particulate matter into the atmosphere, which has significant implications for atmospheric chemistry and climatic change. In this study, emissions from open biomass burning over tropical Asia were evaluated during seven fire years from 2000 to 2006 (1 March 2000–31 February 2007). The size of the burned areas was estimated from newly published 1-km L3JRC and 500-m MODIS burned area products (MCD45A1). Available fuel loads...

  14. Introduction to tropical geometry

    CERN Document Server

    Maclagan, Diane

    2015-01-01

    Tropical geometry is a combinatorial shadow of algebraic geometry, offering new polyhedral tools to compute invariants of algebraic varieties. It is based on tropical algebra, where the sum of two numbers is their minimum and the product is their sum. This turns polynomials into piecewise-linear functions, and their zero sets into polyhedral complexes. These tropical varieties retain a surprising amount of information about their classical counterparts. Tropical geometry is a young subject that has undergone a rapid development since the beginning of the 21st century. While establishing itself as an area in its own right, deep connections have been made to many branches of pure and applied mathematics. This book offers a self-contained introduction to tropical geometry, suitable as a course text for beginning graduate students. Proofs are provided for the main results, such as the Fundamental Theorem and the Structure Theorem. Numerous examples and explicit computations illustrate the main concepts. Each of t...

  15. Investigation of tropical cirrus cloud properties using ground based lidar measurements

    Science.gov (United States)

    Dhaman, Reji K.; Satyanarayana, Malladi; Krishnakumar, V.; Mahadevan Pillai, V. P.; Jayeshlal, G. S.; Raghunath, K.; Venkat Ratnam, M.

    2016-05-01

    Cirrus clouds play a significant role in the Earths radiation budget. Therefore, knowledge of geometrical and optical properties of cirrus cloud is essential for the climate modeling. In this paper, the cirrus clouds microphysical and optical properties are made by using a ground based lidar measurements over an inland tropical station Gadanki (13.5°N, 79.2°E), Andhra Pradesh, India. The variation of cirrus microphysical and optical properties with mid cloud temperature is also studied. The cirrus clouds mean height is generally observed in the range of 9-17km with a peak occurrence at 13- 14km. The cirrus mid cloud temperature ranges from -81°C to -46°C. The cirrus geometrical thickness ranges from 0.9- 4.5km. During the cirrus occurrence days sub-visual, thin and dense cirrus were at 37.5%, 50% and 12.5% respectively. The monthly cirrus optical depth ranges from 0.01-0.47, but most (<80%) of the cirrus have values less than 0.1. Optical depth shows a strong dependence with cirrus geometrical thickness and mid-cloud height. The monthly mean cirrus extinction ranges from 2.8E-06 to 8E-05 and depolarization ratio and lidar ratio varies from 0.13 to 0.77 and 2 to 52 sr respectively. A positive correlation exists for both optical depth and extinction with the mid-cloud temperature. The lidar ratio shows a scattered behavior with mid-cloud temperature.

  16. Observation-Based Estimates of Surface Cooling Inhibition by Heavy Rainfall under Tropical Cyclones

    Digital Repository Service at National Institute of Oceanography (India)

    Jourdain, N; Lengaigne, M.; Vialard, J.; Madec, G.; Menkes, C.E.; Vincent, E.M.; Jullien, E.; Barnier, B.

    Tropical cyclones drive intense ocean vertical mixing that explains most of the surface cooling observed in their wake (the "cold wake"). The influence of cyclonic rainfall on the cold wake at a global scale over the 2002-09 period is investigated...

  17. Governance for quality management in smallholder-based tropical food chains

    NARCIS (Netherlands)

    Tilburg, van A.; Trienekens, J.H.; Ruben, R.; Boekel, van M.A.J.S.

    2008-01-01

    Abstract The paper provides a framework that focuses on the linkages between several key dimensions of supply chain organization and performance of perishable tropical food products. The focus is on the relationship between governance regime and quality management. However, two other but related

  18. Base flow-driven shifts in tropical stream temperature regimes across a mean annual rainfall gradient

    Science.gov (United States)

    Ayron M. Strauch; Richard A. MacKenzie; Ralph W. Tingley

    2017-01-01

    Climate change is expected to affect air temperature and watershed hydrology, but the degree to which these concurrent changes affect stream temperature is not well documented in the tropics. How stream temperature varies over time under changing hydrologic conditions is difficult to isolate from seasonal changes in air temperature. Groundwater and bank storage...

  19. Multidimensional remote sensing based mapping of tropical forests and their dynamics

    NARCIS (Netherlands)

    Dutrieux, L.P.

    2016-01-01

    Tropical forests concentrate a large part of the terrestrial biodiversity, provide important resources, and deliver many ecosystem services such as climate regulation, carbon sequestration, and hence climate change mitigation. While in the current context of anthropogenic pressure these forests

  20. Pandemic influenza A (H1N1 2009: epidemiological analysis of cases in a tropical/semi-arid region of Brazil

    Directory of Open Access Journals (Sweden)

    Roberto da Justa Pires Neto

    2013-04-01

    Full Text Available Introduction The year 2009 marked the beginning of a pandemic caused by a new variant of influenza A (H1N1. After spreading through North America, the pandemic influenza virus (H1N1 2009 spread rapidly throughout the world. The aim of this study was to describe the clinical and epidemiological characteristics of cases of pandemic influenza in a tropical/semi-arid region of Brazil. Methods A retrospective study analyzed all suspected cases of pandemic influenza (H1N1 2009 reported in the Ceará State through the National Information System for Notifiable Diseases during the pandemic period between 28 April, 2009 and November 25, 2010. Results A total of 616 suspected cases were notified, 58 (9.4% in the containment phase and 558 (90.6% in the mitigation phase. Most cases were of affected young people resident in the City of Fortaleza, the largest urban center in the State of Ceará. The most frequent symptoms presented by the cases with confirmed infection were fever, cough, myalgia, arthralgia, and nasal congestion. Mortality rate was 0.0009/1,000 inhabitants and lethality was 5.6%. Deaths were observed only in the mitigation phase. Mortality rates were similar for both sexes but were higher in the age group under 5 years. Conclusions The study suggests that the influenza A (H1N1 pandemic in this tropical/semi-arid region had a lower magnitude when compared to states in the Southern and Southeastern regions of Brazil.

  1. Regional Groundwater and Storms Are Hydrologic Controls on the Quality and Export of Dissolved Organic Matter in Two Tropical Rainforest Streams, Costa Rica

    Science.gov (United States)

    Osburn, Christopher L.; Oviedo-Vargas, Diana; Barnett, Emily; Dierick, Diego; Oberbauer, Steven F.; Genereux, David P.

    2018-03-01

    A paired-watershed approach was used to compare the quality and fluxes of dissolved organic matter (DOM) during stormflow and baseflow in two lowland tropical rainforest streams located in northeastern Costa Rica. The Arboleda stream received regional groundwater (RGW) flow, whereas the Taconazo stream did not. DOM quality was assessed with absorbance and fluorescence and stable carbon isotope (δ13C-DOC) values. RGW DOM lacked detectable fluorescence and had specific ultraviolet absorption (SUVA254) and absorbance slope ratio (SR) values consistent with low aromaticity and low molecular weight material, respectively. We attributed these properties to microbial degradation and sorption of humic DOM to mineral surfaces during transport through bedrock. SUVA254 values were lower and SR values were higher in the Arboleda stream during baseflow compared to the Taconazo stream, presumably due to dilution by RGW. However, no significant difference in SUVA254 or SR occurred between the streams during stormflow. SUVA254 was negatively correlated to δ13C-DOC (r2 = 0.61, P runoff containing soil and throughfall C sources. Mean DOC export from the Taconazo stream during the study period was 2.62 ± 0.39 g C m-2 year-1, consistent with other tropical streams, yet mean DOC export from the Arboleda stream was 13.79 ± 2.07 g C m-2 year-1, one of the highest exports reported and demonstrating a substantial impact of old RGW from outside the watershed boundary can have on surface water carbon cycling.

  2. ESA-MERIS 10-Year Mission Reveals Contrasting Phytoplankton Bloom Dynamics in Two Tropical Regions of Northern Australia

    Directory of Open Access Journals (Sweden)

    David Blondeau-Patissier

    2014-04-01

    Full Text Available The spatial and temporal variability of phytoplankton blooms was investigated in two tropical coastal regions of northern Australia using the MEdium Resolution Imaging Spectrometer (MERIS full mission (2002–2012 reduced resolution dataset. Satellite-derived proxies for phytoplankton (Chlorophyll-a (Chl, Fluorescence Line Height (FLH, Maximum Chlorophyll Index (MCI and suspended sediment (Total Suspended Matter (TSM were jointly analyzed for two clusters of the Great Barrier Reef Wet tropics (GBRW; 15°–19.5°S; Queensland and the Van Diemen Gulf (VDG; 9°–13°S; Northern Territory. The analysis of time-series and Hovmöller diagrams of the four MERIS products provided a unique perspective on the processes linking phytoplankton blooms and river runoff, or resuspension, across spatio-temporal scales. Both regions are characterized by a complex oceanography and seasonal inflows of sediment, freshwater and nutrients during the tropical wet season months (November to April. The GBRW is characterized by a great variability in water clarity (Secchi depth 0–25 m. A long history of agricultural land use has led to a large increase in the seasonal discharge of sediments and nutrients, triggering seasonal phytoplankton blooms (>0.4 mg∙m−3 between January and April. In contrast, the VDG is a poorly flushed, turbid (Secchi depth <5 m environment with strong tidal-energy (4–8 m and very limited land use. Phytoplankton blooms here were found to have higher Chl concentrations (>1.0 mg∙m−3 than in the GBRW, occurring up to twice a year between January and April. Over the 10-year MERIS mission, a weak decline in Chl and TSM was observed for the VDG (Sen slope: −2.85%/decade, τ = −0.32 and −3.57%/decade, τ = −0.24; p 0.05, while no significant trend in those two satellite products was observed in the GBRW. Cyanobacteria surface algal blooms occur in both regions between August and October. The MCI and FLH products were found to

  3. Small Drones for Community-Based Forest Monitoring: An Assessment of Their Feasibility and Potential in Tropical Areas

    Directory of Open Access Journals (Sweden)

    Jaime Paneque-Gálvez

    2014-06-01

    Full Text Available Data gathered through community-based forest monitoring (CBFM programs may be as accurate as those gathered by professional scientists, but acquired at a much lower cost and capable of providing more detailed data about the occurrence, extent and drivers of forest loss, degradation and regrowth at the community scale. In addition, CBFM enables greater survey repeatability. Therefore, CBFM should be a fundamental component of national forest monitoring systems and programs to measure, report and verify (MRV REDD+ activities. To contribute to the development of more effective approaches to CBFM, in this paper we assess: (1 the feasibility of using small, low-cost drones (i.e., remotely piloted aerial vehicles in CBFM programs; (2 their potential advantages and disadvantages for communities, partner organizations and forest data end-users; and (3 to what extent their utilization, coupled with ground surveys and local ecological knowledge, would improve tropical forest monitoring. To do so, we reviewed the existing literature regarding environmental applications of drones, including forest monitoring, and drew on our own firsthand experience flying small drones to map and monitor tropical forests and training people to operate them. We believe that the utilization of small drones can enhance CBFM and that this approach is feasible in many locations throughout the tropics if some degree of external assistance and funding is provided to communities. We suggest that the use of small drones can help tropical communities to better manage and conserve their forests whilst benefiting partner organizations, governments and forest data end-users, particularly those engaged in forestry, biodiversity conservation and climate change mitigation projects such as REDD+.

  4. Phylogenetic classification of the world's tropical forests

    DEFF Research Database (Denmark)

    Slik, J. W. Ferry; Franklin, Janet; Arroyo-Rodriguez, Victor

    2018-01-01

    -Pacific counterparts. We also find indications for the existence of a global dry forest region, with representatives in America, Africa, Madagascar, and India. Additionally, a northern-hemisphere Subtropical forest region was identified with representatives in Asia and America, providing support for a link between......Knowledge about the biogeographic affinities of the world's tropical forests helps to better understand regional differences in forest structure, diversity, composition, and dynamics. Such understanding will enable anticipation of region-specific responses to global environmental change. Modern...... phylogenies, in combination with broad coverage of species inventory data, now allow for global biogeographic analyses that take species evolutionary distance into account. Here we present a classification of the world's tropical forests based on their phylogenetic similarity. We identify five principal...

  5. Spatial co-distribution of neglected tropical diseases in the East African Great Lakes region: revisiting the justification for integrated control

    Science.gov (United States)

    Clements, Archie C. A.; Deville, Marie-Alice; Ndayishimiye, Onésime; Brooker, Simon; Fenwick, Alan

    2010-01-01

    Summary OBJECTIVE To determine spatial patterns of co-endemicity of schistosomiasis mansoni and the soil-transmitted helminths (STHs) Ascaris lumbricoides, Trichuris trichiura and hookworm in the Great Lakes region of East Africa, to help plan integrated neglected tropical disease programmes in this region. METHOD Parasitological surveys were conducted in Uganda, Tanzania, Kenya and Burundi in 28 213 children in 404 schools. Bayesian geostatistical models were used to interpolate prevalence of these infections across the study area. Interpolated prevalence maps were overlaid to determine areas of co-endemicity. RESULTS In the Great Lakes region, prevalence was 18.1% for Schistosoma mansoni, 50.0% for hookworm, 6.8% for A. lumbricoides and 6.8% for T. trichiura. Hookworm infection was ubiquitous, whereas S. mansoni, A. lumbricoides and T. trichiura were highly focal. Most areas were endemic (prevalence ≥10%) or hyperendemic (prevalence ≥50%) for one or more STHs, whereas endemic areas for schistosomiasis mansoni were restricted to foci adjacent large perennial water bodies. CONCLUSION Because of the ubiquity of hookworm, treatment programmes are required for STH throughout the region but efficient schistosomiasis control should only be targeted at limited high-risk areas. Therefore, integration of schistosomiasis with STH control is only indicated in limited foci in East Africa. PMID:20409287

  6. Chemical composition of the fruit of two species of tropical dry forest in the coastal region of Ecuador as food source for ruminants

    Directory of Open Access Journals (Sweden)

    Henrry Othón Intriago Mendoza

    2015-04-01

    Full Text Available Fodder species of trees in the coastal region of Manabí are an alternative food to cattle, especia-lly between the months of september and december when the pasture gets scarce. To evaluate their nutritional potential was made a compositional analysis of nutritional parameters to the fruits of Prosopis juliflora (Sw. DC. (Algarrobo and Guazuma ulmifolia Lam. (Guasmo. Botanical characters of these trees and compositional analysis results are described. Furthermore, a comparison of these results with those obtained by other authors by con-sidering the values of protein, fat, fiber, ash and moisture is performed. For the environmental conditions of tropical dry forest, the guasmo presents higher contents of protein, fat, ash and fiber carob, although both species are important in the diet of herbivores, especially in dry seasons as providers of usable nutrients favoring animal nutrition

  7. Unprecedented drought over tropical South America in 2016: significantly under-predicted by tropical SST.

    Science.gov (United States)

    Erfanian, Amir; Wang, Guiling; Fomenko, Lori

    2017-07-19

    Tropical and sub-tropical South America are highly susceptible to extreme droughts. Recent events include two droughts (2005 and 2010) exceeding the 100-year return value in the Amazon and recurrent extreme droughts in the Nordeste region, with profound eco-hydrological and socioeconomic impacts. In 2015-2016, both regions were hit by another drought. Here, we show that the severity of the 2015-2016 drought ("2016 drought" hereafter) is unprecedented based on multiple precipitation products (since 1900), satellite-derived data on terrestrial water storage (since 2002) and two vegetation indices (since 2004). The ecohydrological consequences from the 2016 drought are more severe and extensive than the 2005 and 2010 droughts. Empirical relationships between rainfall and sea surface temperatures (SSTs) over the tropical Pacific and Atlantic are used to assess the role of tropical oceanic variability in the observed precipitation anomalies. Our results indicate that warmer-than-usual SSTs in the Tropical Pacific (including El Niño events) and Atlantic were the main drivers of extreme droughts in South America, but are unable to explain the severity of the 2016 observed rainfall deficits for a substantial portion of the Amazonia and Nordeste regions. This strongly suggests potential contribution of non-oceanic factors (e.g., land cover change and CO2-induced warming) to the 2016 drought.

  8. Estuarine demersal fish assemblage from a transition region between the tropics and the subtropics of the South Atlantic

    Directory of Open Access Journals (Sweden)

    Mauricio Hostim-Silva

    2013-09-01

    Full Text Available The coastal state of Espírito Santo is in the central region of Brazil, where biological productivity is considered low. The objective of this work is to present a current list of demersal, estuarine fish from northern Espírito Santo. This work is based on the compilation of data collected monthly using trawl nets. The ichthyofauna comprises 57 species, within 10 orders and 32 families. The family Sciaenidae has the largest number of species (8, followed by Carangidae (4 and Gerreidae (4. This coincides with what has been found for the Brazilian coast and for the coast of the South Atlantic. It is important to note that the total species richness in the estuaries of northern Espírito Santo is lower than other estuaries of the South West Atlantic coast. Most of the species are widely distributed in the Western Atlantic. Only a small part (14% of the fauna of northern Espírito Santo was evaluated in regards to risk of extinction, but conservation should be prioritized in the area due to overexploitation of species.

  9. Genotype-environment interaction of maternal influence characteristics in Nellore cattle bred in the Brazilian humid tropical regions by reaction norm

    Directory of Open Access Journals (Sweden)

    Jorge Luís Ferreira

    2015-08-01

    Full Text Available Reaction Norm (RN is the study of genotype-environment interaction (GxE that complies with alternative ways of genotypes within different environments. This study was carried out to verify GxE by a reaction norm model of weights at 120 (W120 and 210 (W210 days of age in Nellore cattle raised in the Humid Tropical Regions of Brazil. Environmental gradients were obtained by solutions of contemporary groups which were fitted as co-variables in the random regression model via reaction norms. Mean weight at 120 days of age was 127.97 kg, and environmental gradients ranged between -27 and +26 kg. Average was 185.60 kg at 210 days of age and gradients ranged from -54 to +55 kg. Scale changes in the breeding values and heritability estimates occurred along the gradients for the two weights; the genetic correlations between breeding value breeding values were also similar for both weights. These correlations were high between the close gradients, and low to even negative between extreme environments. Slopes representing the environmental sensitivity were high, with changes of scale and changes in classification of ten bulls with a great numbers of calves for the two traits. When regression slopes of the ten bulls with the highest breeding value breeding values were evaluated, these values were different in W120 from those in W210, perhaps due to the greater influence of maternal effect on W120. These results characterize the influence of GxE on the pre-weaning weights of animals in the humid tropical regions of Brazil. Due to this, it is possible to get greater precision on the predictions of the animals breeding values breeding value. A less biased selection and a greater genetic progress occurred.

  10. An assessment of tropical cyclone representation in a regional reanalysis and a shape metric methodology for studying the evolving precipitation structure prior to and during landfall

    Science.gov (United States)

    Zick, Stephanie E.

    Tropical cyclone (TC) precipitation is intricately organized with multiple scales of phenomena collaborating to harness the massive energy required to support these storms. During landfall, a TC leaves the tropical oceanic environment and encounters a wide range of continental air mass regimes. Although evolving precipitation patterns are qualitatively observed in these storms during landfall, the timing and spatial variability of these structural changes have yet to be quantified or documented. This dissertation integrates meteorological and geographic concepts to explore the representation and evolution of TC rainfall at the crucial time of landfall when coastal and inland communities and environments are most vulnerable to TC-associated flooding. This research begins with a two-part assessment of TC representation in the North American Regional Reanalysis (NARR), which is selected for its documented skill in characterizing North American precipitation patterns. Due to the sparsely available data over the tropical oceans, spatial biases exist in both global and regional reanalysis datasets. However, within the NARR the introduction of over-ocean precipitation assimilation in 2004 leads to an improved analysis of TC warm core structure, which results in an improved precipitation forecast. Collectively, these studies highlight the need for sophisticated observational and data assimilation systems. Specifically, the development of new, novel precipitation assimilation techniques will be valuable to the construction of better-quality forecasting tools with more authentic TC representation. In the third study, the fundamental geographic concept of compactness is utilized to construct a shape metric methodology for investigating (a) the overall evolution of and (b) the spatiotemporal positions of significant changes to synoptic-scale precipitation structure. These metrics encompass the characteristic geometries of TCs moving into the mid-latitudes: asymmetry

  11. Evaluating the Impact of Localized GCM Grid Refinement on Regional Tropical Cyclone Climatology and Synoptic Variability using Variable-Resolution CAM-SE

    Science.gov (United States)

    Zarzycki, C.; Jablonowski, C.

    2013-12-01

    Using General Circulation Models (GCMs) to resolve sub-synoptic features in climate simulations has traditionally been difficult due to a multitude of atmospheric processes operating at subgrid scales requiring significant parameterization. For example, at traditional GCM horizontal grid resolutions of 50-300 km, tropical cyclones are generally under-resolved. This paper explores a novel variable-resolution global modeling approach that allows for high spatial resolutions in areas of interest, such as low-latitude ocean basins where tropical cyclogenesis occurs. Such multi-resolution GCM designs allow for targeted use of computing resources at the regional level while maintaining a globally-continuous model domain and may serve to bridge the gap between GCMs with uniform grids and boundary-forced limited area models. A statically-nested, variable-resolution option has recently been introduced into the Community Atmosphere Model's (CAM) Spectral Element (SE) dynamical core. A 110 km CAM-SE grid with a 28 km nest over the Atlantic Ocean has been coupled to land, ocean, and ice components within the Community Earth System Model (CESM). We present the results of a multi-decadal climate simulation using Atmospheric Model Intercomparison Project (AMIP) protocols, which force the model with historical sea surface temperatures and airborne chemical species. To investigate whether refinement improves the representation of tropical cyclones, we compare Atlantic storm statistics to observations with specific focus paid to intensity profiles and track densities. The resolution dependance of both cyclone structure and objective detection between refined and unrefined basins is explored. In addition, we discuss the potential impact of using variable-resolution grids on the large-scale synoptic interannual variability by comparing refined grid simulations to reanalysis data as well as an unrefined, globally-uniform CAM-SE simulation with identical forcing. We also evaluate the

  12. Three Decades of Remote Sensing Based Tropical Forests Phenological Patterns and Trends

    Science.gov (United States)

    Didan, K.

    2010-12-01

    The faint climatic seasonality of tropical rain forests is believed to be the reason these biomes lack strong and detectable seasonality. Forest seasonality is a critical element of ecosystem functions. It moderates the echo-hydrology, carbon, and nutrient exchange of the area. While deciduous forests exhibit distinct and strong seasonality, tropical forests do not, yet they play a large role in the cycling of energy and mass. Tropical forests represent a large percentage of vegetated land and their importance to the Earth system stems from their biological diversity, their habitat role, their role in regulating global weather, and the role they play in carbon storage. While Tropical forests are well buffered by their sheer size, their vulnerability to climate change is exacerbated by the human pressure. All of this begs the questions of what are the patterns and characteristic of tropical forests phenology and are there any detectable trends over the last three decades of synoptic remote sensing. These three decades comprise different episodes of droughts and an ever increasing level of human encroachment. In so far understanding the function and dynamic of these biomes, field studies continue to play a major role, but synoptic remote sensing is emerging as a viable tool to addressing the spatial and temporal scale associated with this problem. Recent studies of Brazilian rainforest with synoptic remote sensing point to a sizable seasonal signal coincident with the dry season. However, these studies were not extensive in time or space and did not look at other rainforests. Using data from AVHRR and MODIS, we generated a 30 year record of the 2 bands Enhance Vegetation Index (EVI2), and analyzed the patterns and trends of land surface phenology across all tropical forests using the homogeneous phenology cluster approach. We chose EVI because of its superior performance over these dense forests, and we selected the homogeneous phenology cluster approach to abate the

  13. Relationships Between Land Use and Stream Nutrient Concentrations in a Highly Urbanized Tropical Region of Brazil: Thresholds and Riparian Zones.

    Science.gov (United States)

    Tromboni, F; Dodds, W K

    2017-07-01

    Nutrient enrichment in streams due to land use is increasing globally, reducing water quality and causing eutrophication of downstream fresh and coastal waters. In temperate developed countries, the intensive use of fertilizers in agriculture is a main driver of increasing nutrient concentrations, but high levels and fast rates of urbanization can be a predominant issue in some areas of the developing world. We investigated land use in the highly urbanized tropical State of Rio de Janeiro, Brazil. We collected total nitrogen, total phosphorus, and inorganic nutrient data from 35 independent watersheds distributed across the State and characterized land use at a riparian and entire watershed scales upstream from each sample station, using ArcGIS. We used regression models to explain land use influences on nutrient concentrations and to assess riparian protection relationships to water quality. We found that urban land use was the primary driver of nutrient concentration increases, independent of the scale of analyses and that urban land use was more concentrated in the riparian buffer of streams than in the entire watersheds. We also found significant thresholds that indicated strong increases in nutrient concentrations with modest increases in urbanization reaching maximum nutrient concentrations between 10 and 46% urban cover. These thresholds influenced calculation of reference nutrient concentrations, and ignoring them led to higher estimates of these concentrations. Lack of sewage treatment in concert with urban development in riparian zones apparently leads to the observation that modest increases in urban land use can cause large increases in nutrient concentrations.

  14. Accuracy Assessment of Lidar-Derived Digital Terrain Model (dtm) with Different Slope and Canopy Cover in Tropical Forest Region

    Science.gov (United States)

    Salleh, M. R. M.; Ismail, Z.; Rahman, M. Z. A.

    2015-10-01

    Airborne Light Detection and Ranging (LiDAR) technology has been widely used recent years especially in generating high accuracy of Digital Terrain Model (DTM). High density and good quality of airborne LiDAR data promises a high quality of DTM. This study focussing on the analysing the error associated with the density of vegetation cover (canopy cover) and terrain slope in a LiDAR derived-DTM value in a tropical forest environment in Bentong, State of Pahang, Malaysia. Airborne LiDAR data were collected can be consider as low density captured by Reigl system mounted on an aircraft. The ground filtering procedure use adaptive triangulation irregular network (ATIN) algorithm technique in producing ground points. Next, the ground control points (GCPs) used in generating the reference DTM and these DTM was used for slope classification and the point clouds belong to non-ground are then used in determining the relative percentage of canopy cover. The results show that terrain slope has high correlation for both study area (0.993 and 0.870) with the RMSE of the LiDAR-derived DTM. This is similar to canopy cover where high value of correlation (0.989 and 0.924) obtained. This indicates that the accuracy of airborne LiDAR-derived DTM is significantly affected by terrain slope and canopy caver of study area.

  15. ACCURACY ASSESSMENT OF LIDAR-DERIVED DIGITAL TERRAIN MODEL (DTM WITH DIFFERENT SLOPE AND CANOPY COVER IN TROPICAL FOREST REGION

    Directory of Open Access Journals (Sweden)

    M. R. M. Salleh

    2015-10-01

    Full Text Available Airborne Light Detection and Ranging (LiDAR technology has been widely used recent years especially in generating high accuracy of Digital Terrain Model (DTM. High density and good quality of airborne LiDAR data promises a high quality of DTM. This study focussing on the analysing the error associated with the density of vegetation cover (canopy cover and terrain slope in a LiDAR derived-DTM value in a tropical forest environment in Bentong, State of Pahang, Malaysia. Airborne LiDAR data were collected can be consider as low density captured by Reigl system mounted on an aircraft. The ground filtering procedure use adaptive triangulation irregular network (ATIN algorithm technique in producing ground points. Next, the ground control points (GCPs used in generating the reference DTM and these DTM was used for slope classification and the point clouds belong to non-ground are then used in determining the relative percentage of canopy cover. The results show that terrain slope has high correlation for both study area (0.993 and 0.870 with the RMSE of the LiDAR-derived DTM. This is similar to canopy cover where high value of correlation (0.989 and 0.924 obtained. This indicates that the accuracy of airborne LiDAR-derived DTM is significantly affected by terrain slope and canopy caver of study area.

  16. Extent of Integration of Priority Interventions into General Health Systems: A Case Study of Neglected Tropical Diseases Programme in the Western Region of Ghana.

    Science.gov (United States)

    Mensah, Ernest O; Aikins, Moses K; Gyapong, Margaret; Anto, Francis; Bockarie, Moses J; Gyapong, John O

    2016-05-01

    The global health system has a large arsenal of interventions, medical products and technologies to address current global health challenges. However, identifying the most effective and efficient strategies to deliver these resources to where they are most needed has been a challenge. Targeted and integrated interventions have been the main delivery strategies. However, the health system discourse increasingly favours integrated strategies in the context of functionally merging targeted interventions with multifunctional health care delivery systems with a focus on strengthening country health systems to deliver needed interventions. Neglected Tropical Diseases (NTD) have been identified to promote and perpetuate poverty hence there has been global effort to combat these diseases. The Neglected Tropical Diseases Programme (NTDP) in Ghana has a national programme team and office, however, it depends on the multifunctional health delivery system at the regional and district level to implement interventions. The NTDP seeks further health system integration to accelerate achievement of coverage targets. The study estimated the extent of integration of the NTDP at the national, regional and district levels to provide evidence to guide further integration. The research design was a descriptive case study that interviewed key persons involved in the programme at the three levels of the health system as well as extensive document review. Integration was assessed on two planes-across health system functions-stewardship and governance, financing, planning, service delivery, monitoring and evaluation and demand generation; and across three administrative levels of the health system-national, regional and district. A composite measure of integration designated Cumulative Integration Index (CII) with a range of 0.00-1.00 was used to estimate extent of integration at the three levels of the health system. Service delivery was most integrated while financing and planning were

  17. Characterizing Tropical Forest Structure using Field-based Measurements and a Terrestrial Lidar

    Science.gov (United States)

    Palace, M. W.; Sullivan, F.; Ducey, M. J.; Herrick, C.

    2015-12-01

    Forest structure comprises numerous quantifiable components of forest biometric characteristics, one of which is tree architecture. This structural component is important in the understanding of the past and future trajectories of these biomes. Tropical forests are often considered the most structurally complex and yet least understood of forested ecosystems. New technologies have provided novel avenues for quantifying properties of forested ecosystems, one of which is LIght Detection And Ranging (lidar). This sensor can be deployed on satellite, aircraft, unmanned aerial vehicles, and terrestrial platforms. In this study we examined the efficacy of a terrestrial lidar scanner (TLS) system in a tropical forest to estimate forest structure. Our study was conducted in January 2012 at La Selva, Costa Rica at twenty locations in predominantly undisturbed forest. At these locations we collected field measured biometric attributes using a variable plot design. We also collected TLS data from the center of each plot. Using this data we developed relative vegetation profiles (RVPs) and calculated a series of parameters including entropy, FFT, number of layers and plant area index to develop statistical relationships with field data. We developed statistical models using multiple linear regressions, all of which converged on statistically significant relationships with the strongest relationship being for mean crown depth (r2 = 0.87, p information on tropical forest structure.

  18. An individual-based model of skipjack tuna (Katsuwonus pelamis) movement in the tropical Pacific ocean

    Science.gov (United States)

    Scutt Phillips, Joe; Sen Gupta, Alex; Senina, Inna; van Sebille, Erik; Lange, Michael; Lehodey, Patrick; Hampton, John; Nicol, Simon

    2018-05-01

    The distribution of marine species is often modeled using Eulerian approaches, in which changes to population density or abundance are calculated at fixed locations in space. Conversely, Lagrangian, or individual-based, models simulate the movement of individual particles moving in continuous space, with broader-scale patterns such as distribution being an emergent property of many, potentially adaptive, individuals. These models offer advantages in examining dynamics across spatiotemporal scales and making comparisons with observations from individual-scale data. Here, we introduce and describe such a model, the Individual-based Kinesis, Advection and Movement of Ocean ANimAls model (Ikamoana), which we use to replicate the movement processes of an existing Eulerian model for marine predators (the Spatial Ecosystem and Population Dynamics Model, SEAPODYM). Ikamoana simulates the movement of either individual or groups of animals by physical ocean currents, habitat-dependent stochastic movements (kinesis), and taxis movements representing active searching behaviours. Applying our model to Pacific skipjack tuna (Katsuwonus pelamis), we show that it accurately replicates the evolution of density distribution simulated by SEAPODYM with low time-mean error and a spatial correlation of density that exceeds 0.96 at all times. We demonstrate how the Lagrangian approach permits easy tracking of individuals' trajectories for examining connectivity between different regions, and show how the model can provide independent estimates of transfer rates between commonly used assessment regions. In particular, we find that retention rates in most assessment regions are considerably smaller (up to a factor of 2) than those estimated by this population of skipjack's primary assessment model. Moreover, these rates are sensitive to ocean state (e.g. El Nino vs La Nina) and so assuming fixed transfer rates between regions may lead to spurious stock estimates. A novel feature of the

  19. Evaluation of Cold Tolerant High Yielding Oil Palm Germplasm in Guangdong Province of South China, a Northern Tropical Region

    International Nuclear Information System (INIS)

    Xianhai, Z.; Denglang, P.; Zhao, L.; Junming, C.; Weifu, L.

    2016-01-01

    An evaluation of the vegetative growth, yield components and cold resistance traits from 38 pre-selected individual oil palm plants grown in six regions (populations) at the latitude (LAT) range between 20 degree N and 23 degree N in Guangdong Province, China was carried out during the period from April 2010 to April 2015. Analysis of variance showed significant differences in traits between the individual palms or the populations [except sex-ratio of female inflorescence and fruit bunch to female inflorescence, male inflorescence and fruit bunch (%) (SR)]. Phenotypic correlation analysis showed that bunch number (NB) was positively correlated with fresh fruit bunch (FFB), but not significantly with average bunch weight (ABW). For the individual palms, it was found that the higher the LAT the lower the frond production (FP) and LT 50 and the higher fruit compaction rate (FCR), and the higher the LT 50 the lower the ABW. For the populations, the higher the LAT the higher the ABW and the lower the abortion ratio of female inflorescence to female inflorescence and fruit bunch (%) (RAFM). Path coefficient analysis further revealed that for the individual palms ABW was the major determinant in both FFB and NB, and mainly determined by normal fruit higher per bunch (kg) (ANFW) and percent of ANFW to ABW (%) (F/B). For the populations, the major determining factors were ratio of aborted fruit bunch to fruit bunch (%) (ABR) for FFB and NB, and inflorescence (male, female, bisexual and non-anthesis) and fruit bunch numbers per year (No.) NIB and LT 50 for ABW. MM5 palm and Huazhou population were selected based on the major determining factors as high-yielding cold tolerant palm and population, respectively, which was consistent with the results of analysis of variance. (author)

  20. Forecasting Precipitation over the MENA Region: A Data Mining and Remote Sensing Based Approach

    Science.gov (United States)

    Elkadiri, R.; Sultan, M.; Elbayoumi, T.; Chouinard, K.

    2015-12-01

    We developed and applied an integrated approach to construct predictive tools with lead times of 1 to 12 months to forecast precipitation amounts over the Middle East and North Africa (MENA) region. The following steps were conducted: (1) acquire and analyze temporal remote sensing-based precipitation datasets (i.e. Tropical Rainfall Measuring Mission [TRMM]) over five main water source regions in the MENA area (i.e. Atlas Mountains in Morocco, Southern Sudan, Red Sea Hills of Yemen, and Blue Nile and White Nile source areas) throughout the investigation period (1998 to 2015), (2) acquire and extract monthly values for all of the climatic indices that are likely to influence the climatic patterns over the MENA region (e.g., Northern Atlantic Oscillation [NOI], Southern Oscillation Index [SOI], and Tropical North Atlantic Index [TNA]); and (3) apply data mining methods to extract relationships between the observed precipitation and the controlling factors (climatic indices) and use predictive tools to forecast monthly precipitation over each of the identified pilot study areas. Preliminary results indicate that by using the period from January 1998 until August 2012 for model training and the period from September 2012 to January 2015 for testing, precipitation can be successfully predicted with a three-months lead over South West Yemen, Atlas Mountains in Morocco, Southern Sudan, Blue Nile sources and White Nile sources with confidence (Pearson correlation coefficient: 0.911, 0.823, 0.807, 0.801 and 0.895 respectively). Future work will focus on applying this technique for prediction of precipitation over each of the climatically contiguous areas of the MENA region. If our efforts are successful, our findings will lead the way to the development and implementation of sound water management scenarios for the MENA countries.

  1. Pneumonia in the tropics.

    Science.gov (United States)

    Lim, Tow Keang; Siow, Wen Ting

    2018-01-01

    Pneumonia in the tropics poses a heavy disease burden. The complex interplay of climate change, human migration influences and socio-economic factors lead to changing patterns of respiratory infections in tropical climate but also increasingly in temperate countries. Tropical and poorer countries, especially South East Asia, also bear the brunt of the global tuberculosis (TB) pandemic, accounting for almost one-third of the burden. But, as human migration patterns evolve, we expect to see more TB cases in higher income as well as temperate countries, and rise in infections like scrub typhus from ecotourism activities. Fuelled by the ease of air travel, novel zoonotic infections originating from the tropics have led to global respiratory pandemics. As such, clinicians worldwide should be aware of these new conditions as well as classical tropical bacterial pneumonias such as melioidosis. Rarer entities such as co-infections of leptospirosis and chikungunya or dengue will need careful consideration as well. In this review, we highlight aetiologies of pneumonia seen more commonly in the tropics compared with temperate regions, their disease burden, variable clinical presentations as well as impact on healthcare delivery. © 2017 Asian Pacific Society of Respirology.

  2. Tropical cyclogenesis in a tropical wave critical layer: easterly waves

    Directory of Open Access Journals (Sweden)

    T. J. Dunkerton

    2009-08-01

    cyclonic vorticity and weak deformation by the resolved flow, (ii containment of moisture entrained by the developing gyre and/or lofted by deep convection therein, (iii confinement of mesoscale vortex aggregation, (iv a predominantly convective type of heating profile, and (v maintenance or enhancement of the parent wave until the vortex becomes a self-sustaining entity and emerges from the wave as a tropical depression. The entire sequence is likened to the development of a marsupial infant in its mother's pouch. These ideas are formulated in three new hypotheses describing the flow kinematics and dynamics, moist thermodynamics and wave/vortex interactions comprising the "marsupial paradigm". A survey of 55 named tropical storms in 1998–2001 reveals that actual critical layers sometimes resemble the ideal east-west train of cat's eyes, but are usually less regular, with one or more recirculation regions in the co-moving frame. It is shown that the kinematics of isolated proto-vortices carried by the wave also can be visualized in a frame of reference translating at or near the phase speed of the parent wave. The proper translation speeds for wave and vortex may vary with height owing to vertical shear and wave-vortex interaction. Some implications for entrainment/containment of vorticity and moisture in the cat's eye are discussed from this perspective, based on the observational survey.

  3. Vegetation-climate feedback causes reduced precipitation and tropical rainforest cover in CMIP5 regional Earth system model simulation over Africa

    Science.gov (United States)

    Wu, M.; Smith, B.; Samuelsson, P.; Rummukainen, M.; Schurgers, G.

    2012-12-01

    We applied a coupled regional climate-vegetation model, RCA-GUESS (Smith et al. 2011), over the CORDEX Africa domain, forced by boundary conditions from a CanESM2 CMIP5 simulation under the RCP8.5 future climate scenario. The simulations were from 1961 to 2100 and covered the African continent at a horizontal grid spacing of 0.44°. RCA-GUESS simulates changes in the phenology, productivity, relative cover and population structure of up to eight plant function types (PFTs) in response to forcing from the climate part of the model. These vegetation changes feed back to simulated climate through dynamic adjustments in surface energy fluxes and surface properties. Changes in the net ecosystem-atmosphere carbon flux and its components net primary production (NPP), heterotrophic respiration and emissions from biomass burning were also simulated but do not feed back to climate in our model. Constant land cover was assumed. We compared simulations with and without vegetation feedback switched "on" to assess the influence of vegetation-climate feedback on simulated climate, vegetation and ecosystem carbon cycling. Both positive and negative warming feedbacks were identified in different parts of Africa. In the Sahel savannah zone near 15°N, reduced vegetation cover and productivity, and mortality caused by a deterioration of soil water conditions led to a positive warming feedback mediated by decreased evapotranspiration and increased sensible heat flux between vegetation and the atmosphere. In the equatorial rainforest stronghold region of central Africa, a feedback syndrome characterised by reduced plant production and LAI, a dominance shift from tropical trees to grasses, reduced soil water and reduced rainfall was identified. The likely underlying mechanism was a decline in evaporative water recycling associated with sparser vegetation cover, reminiscent of Earth system model studies in which a similar feedback mechanism was simulated to force dieback of tropical

  4. Temporal assemblage turnovers of intertidal foraminiferal communities from tropical (SE Caribbean) and temperate (NE England and SW Spain) regions

    Science.gov (United States)

    Costelloe, Ashleigh; Wilson, Brent; Horton, Benjamin P.; Hayek, Lee-Ann C.

    2018-05-01

    This is the first quantitative study of temporal assemblage turnovers of the relationships between intertidal foraminifera. Time series datasets collected from tropical Caroni Swamp and Claxton Bay (Trinidad, SE Caribbean) and temperate Cowpen Marsh (NE England, U.K.) and Bay of Cadiz (SW Spain) were used. The assemblage turnover index (ATI) examined species interrelationships through comparisons of monthly or biweekly species proportional abundances over one or two years. Species contributing to major assemblage turnovers (ATI > x + σ) were identified using the conditioned on-boundary index (CoBI). Foraminiferal species are heterogeneously distributed within the sediment; multiple sample stations at a study location cumulatively represent the foraminiferal metacommunity and clusters represent foraminiferal assemblages. The ATI and CoBI were applied to the proportional abundances of live specimens recorded for the metacommunity and assemblages at each location. At Caroni Swamp and Claxton Bay, major assemblage turnovers were driven by the most abundant species and the majority coincided with seasonal change or the arrival of the seasonal Orinoco plume in the Gulf of Paria. Seasonal turnovers of the foraminiferal metacommunities at temperate Cowpen Marsh and Bay of Cádiz occurred during the summer and winter. Major assemblage turnovers in the upper Cowpen Marsh occurred in the summer, and the lower marsh in the winter. Foraminiferans are useful bioindicators for monitoring the health of coastal environments. Understanding foraminiferal population dynamics will allow cyclical changes to be differentiated from abrupt and persistent changes, which are related to anthropogenic disturbances or long-term climate change. The ATI and CoBI are useful indices for quantitatively exploring relationships of foraminiferal populations over time.

  5. Linking Tropical Forest Function to Hydraulic Traits in a Size-Structured and Trait-Based Model

    Science.gov (United States)

    Christoffersen, B. O.; Gloor, M.; Fauset, S.; Fyllas, N.; Galbraith, D.; Baker, T. R.; Rowland, L.; Fisher, R.; Binks, O.; Sevanto, S.; Xu, C.; Jansen, S.; Choat, B.; Mencuccini, M.; McDowell, N. G.; Meir, P.

    2015-12-01

    A major weakness of forest ecosystem models is their inability to capture the diversity of responses to changes in water availability, severely hampering efforts to predict the fate of tropical forests under climate change. Such models often prescribe moisture sensitivity using heuristic response functions that are uniform across all individuals and lack important knowledge about trade-offs in hydraulic traits. We address this weakness by implementing a process representation of plant hydraulics into an individual- and trait-based model (Trait Forest Simulator; TFS) intended for application at discrete sites where community-level distributions of stem and leaf trait spectra (wood density, leaf mass per area, leaf nitrogen and phosphorus content) are known. The model represents a trade-off in the safety and efficiency of water conduction in xylem tissue through hydraulic traits, while accounting for the counteracting effects of increasing hydraulic path length and xylem conduit taper on whole-plant hydraulic resistance with increasing tree size. Using existing trait databases and additional meta-analyses from the rich literature on tropical tree ecophysiology, we obtained all necessary hydraulic parameters associated with xylem conductivity, vulnerability curves, pressure-volume curves, and hydraulic architecture (e.g., leaf-to-sapwood area ratios) as a function of the aforementioned traits and tree size. Incorporating these relationships in the model greatly improved the diversity of tree response to seasonal changes in water availability as well as in response to drought, as determined by comparison with field observations and experiments. Importantly, this individual- and trait-based framework provides a testbed for identifying both critical processes and functional traits needed for inclusion in coarse-scale Dynamic Global Vegetation Models, which will lead to reduced uncertainty in the future state of tropical forests.

  6. Strengthening regional innovation through network-based innovation brokering

    OpenAIRE

    Svare, Helge; Gausdal, Anne Haugen

    2015-01-01

    The primary objective of this paper is to demonstrate how regional innovation system theory may be translated into manageable micro-level methods with the potential for strengthening the productive dynamics of a regional innovation system. The paper meets this objective by presenting network-based innovation brokering (NBIB), a practical method designed using insights from regional innovation system theory and trust theory. Five cases from two Norwegian regional innovation networks show that ...

  7. Testing the ecotoxicology of vegetable versus mineral based lubricating oils: 2. Induction of mixed function oxidase enzymes in barramundi, Lates calcarifer, a tropical fish species

    Energy Technology Data Exchange (ETDEWEB)

    Mercurio, Philip; Burns, Kathryn A.; Cavanagh, Joanne

    2004-05-01

    An increasing number of vegetable-based oils are being developed as environmentally friendly alternatives to petroleum products. However, toxicity towards key tropical marine species has not been investigated. In this study we used laboratory-based biomarker induction experiments to compare the relative stress of a vegetable-based lubricating oil for marine 2-stroke engines with its mineral oil-based counterpart on tropical fish. The sub-lethal stress of 2-stoke outboard lubricating oils towards the fish Lates calcarifer (barramundi) was examined using liver microsomal mixed function oxidase (MFO) induction assays. This study is the first investigation into the use of this key commercial species in tropical North Queensland, Australia in stress assessment of potential hydrocarbon pollution using ethoxyresorufin O-deethylase (EROD) induction. Our results indicated that barramundi provide a wide range of inducible rates of EROD activity in response to relevant organic stressors. The vegetable- and mineral-based lubricants induced significant EROD activity at 1.0 mg kg{sup -1} and there was no significant difference between the two oil treatments at that concentration. At increasing concentrations of 2 and 3 mg kg{sup -1}, the mineral-based lubricant resulted in slightly higher EROD activity than the vegetable-based lubricant. The EROD activity of control and treated barramundi are found to be within ranges for other species from temperate and tropical environments. These results indicate that vegetable-based lubricants may be less stressful to barramundi than their mineral counterparts at concentrations of lubricant {>=}2 mg kg{sup -1}. There is great potential for this species to be used in the biomonitoring of waterways around tropical North Queensland and SE Asia. - Vegetable-based lubricating oils appear to cause a tropical fish species less stress than mineral oils.

  8. Testing the ecotoxicology of vegetable versus mineral based lubricating oils: 2. Induction of mixed function oxidase enzymes in barramundi, Lates calcarifer, a tropical fish species

    International Nuclear Information System (INIS)

    Mercurio, Philip; Burns, Kathryn A.; Cavanagh, Joanne

    2004-01-01

    An increasing number of vegetable-based oils are being developed as environmentally friendly alternatives to petroleum products. However, toxicity towards key tropical marine species has not been investigated. In this study we used laboratory-based biomarker induction experiments to compare the relative stress of a vegetable-based lubricating oil for marine 2-stroke engines with its mineral oil-based counterpart on tropical fish. The sub-lethal stress of 2-stoke outboard lubricating oils towards the fish Lates calcarifer (barramundi) was examined using liver microsomal mixed function oxidase (MFO) induction assays. This study is the first investigation into the use of this key commercial species in tropical North Queensland, Australia in stress assessment of potential hydrocarbon pollution using ethoxyresorufin O-deethylase (EROD) induction. Our results indicated that barramundi provide a wide range of inducible rates of EROD activity in response to relevant organic stressors. The vegetable- and mineral-based lubricants induced significant EROD activity at 1.0 mg kg -1 and there was no significant difference between the two oil treatments at that concentration. At increasing concentrations of 2 and 3 mg kg -1 , the mineral-based lubricant resulted in slightly higher EROD activity than the vegetable-based lubricant. The EROD activity of control and treated barramundi are found to be within ranges for other species from temperate and tropical environments. These results indicate that vegetable-based lubricants may be less stressful to barramundi than their mineral counterparts at concentrations of lubricant ≥2 mg kg -1 . There is great potential for this species to be used in the biomonitoring of waterways around tropical North Queensland and SE Asia. - Vegetable-based lubricating oils appear to cause a tropical fish species less stress than mineral oils

  9. Tropical Cyclone Report, 1988

    Science.gov (United States)

    1988-01-01

    Cmdr. David Gray; National Weather Service 5. Cooperation with the Naval Environmental Pacific Region for the startup of 24-hour operatiois at Ponape...0.1 27.7 TOTAL CASES 3 1 1 4 12 27 54 56 30 25 7 1 221 * (GRAY, 1979) TABLE 4-3 ANNUAL VARIATION C SOTR MUSHER TROPICAL CYCLOUZ BY O(EN BASIN SOUTH

  10. Prospects and Challenges in tropical isotope dendroclimatology

    Science.gov (United States)

    Evans, M. N.; Anchukaitis, K. J.; White, S. R.; Ektvedt, T. M.; Penniston, R. C.; Rheaume, M. M.; Bowman, D. M.

    2008-12-01

    We review a stable isotope-based approach to the development, modeling, interpretation, and analysis of hydrometeorological estimates from tropical trees. The strategy overcomes the common problem of missing, intermittent or non-annual ring structure in tropical trees by relying instead on the observation of the annual wet-dry seasonality typical to tropical environments as mirrored in the oxygen isotopic composition of wood-derived α-cellulose. We explore regions for which forward modeling of the proxy system would expect us to resolve hydrometeorological variations associated with the El Niño-Southern Oscillation (ENSO) phenomenon, rather than being limited to regions with tree species or environments producing verifiable annual ring chronologies. A modified protocol allows for rapid, simple and non-toxic micro-extraction of pure α-cellulose, which is isotopically indistinguishable from that produced by more classical means. We describe a new reactor for the pyrolysis of α-cellulose in an induction heater, which permits isotopic analysis of α-cellulose samples as small as 30μg, and as many as 100 automated sample analyses per day. A forward model adapted for tropical environments can be used to test and refine the interpretation of the isotopic data, and to predict locales for which we should be able to maximize the paleoclimatic potential of future sample collections. We have found the modeled isotopic chronometer and raingage in agreement with independent chronological controls in a variety of environments and tree species in Costa Rica, Indonesia, Brazil, Peru and Australia. Development of long hydrometeorological records from the terrestrial tropics is underway not only by our group, but by a growing number of collaborators and colleagues. Together we should be able to build a network of paleoprecipitation records and better understand the linkages between tropical surface ocean temperatures and large-scale drought.

  11. A simple algorithm for large-scale mapping of evergreen forests in tropical America, Africa and Asia

    Science.gov (United States)

    Xiangming Xiao; Chandrashekhar M. Biradar; Christina Czarnecki; Tunrayo Alabi; Michael Keller

    2009-01-01

    The areal extent and spatial distribution of evergreen forests in the tropical zones are important for the study of climate, carbon cycle and biodiversity. However, frequent cloud cover in the tropical regions makes mapping evergreen forests a challenging task. In this study we developed a simple and novel mapping algorithm that is based on the temporal profile...

  12. MiSNPDb: a web-based genomic resources of tropical ecology fruit mango (Mangifera indica L.) for phylogeography and varietal differentiation.

    Science.gov (United States)

    Iquebal, M A; Jaiswal, Sarika; Mahato, Ajay Kumar; Jayaswal, Pawan K; Angadi, U B; Kumar, Neeraj; Sharma, Nimisha; Singh, Anand K; Srivastav, Manish; Prakash, Jai; Singh, S K; Khan, Kasim; Mishra, Rupesh K; Rajan, Shailendra; Bajpai, Anju; Sandhya, B S; Nischita, Puttaraju; Ravishankar, K V; Dinesh, M R; Rai, Anil; Kumar, Dinesh; Sharma, Tilak R; Singh, Nagendra K

    2017-11-02

    Mango is one of the most important fruits of tropical ecological region of the world, well known for its nutritive value, aroma and taste. Its world production is >45MT worth >200 billion US dollars. Genomic resources are required for improvement in productivity and management of mango germplasm. There is no web-based genomic resources available for mango. Hence rapid and cost-effective high throughput putative marker discovery is required to develop such resources. RAD-based marker discovery can cater this urgent need till whole genome sequence of mango becomes available. Using a panel of 84 mango varieties, a total of 28.6 Gb data was generated by ddRAD-Seq approach on Illumina HiSeq 2000 platform. A total of 1.25 million SNPs were discovered. Phylogenetic tree using 749 common SNPs across these varieties revealed three major lineages which was compared with geographical locations. A web genomic resources MiSNPDb, available at http://webtom.cabgrid.res.in/mangosnps/ is based on 3-tier architecture, developed using PHP, MySQL and Javascript. This web genomic resources can be of immense use in the development of high density linkage map, QTL discovery, varietal differentiation, traceability, genome finishing and SNP chip development for future GWAS in genomic selection program. We report here world's first web-based genomic resources for genetic improvement and germplasm management of mango.

  13. Landslide susceptibility mapping using GIS-based statistical models and Remote sensing data in tropical environment.

    Science.gov (United States)

    Shahabi, Himan; Hashim, Mazlan

    2015-04-22

    This research presents the results of the GIS-based statistical models for generation of landslide susceptibility mapping using geographic information system (GIS) and remote-sensing data for Cameron Highlands area in Malaysia. Ten factors including slope, aspect, soil, lithology, NDVI, land cover, distance to drainage, precipitation, distance to fault, and distance to road were extracted from SAR data, SPOT 5 and WorldView-1 images. The relationships between the detected landslide locations and these ten related factors were identified by using GIS-based statistical models including analytical hierarchy process (AHP), weighted linear combination (WLC) and spatial multi-criteria evaluation (SMCE) models. The landslide inventory map which has a total of 92 landslide locations was created based on numerous resources such as digital aerial photographs, AIRSAR data, WorldView-1 images, and field surveys. Then, 80% of the landslide inventory was used for training the statistical models and the remaining 20% was used for validation purpose. The validation results using the Relative landslide density index (R-index) and Receiver operating characteristic (ROC) demonstrated that the SMCE model (accuracy is 96%) is better in prediction than AHP (accuracy is 91%) and WLC (accuracy is 89%) models. These landslide susceptibility maps would be useful for hazard mitigation purpose and regional planning.

  14. Evaluation of Inter-Hemispheric Characteristics of the Tropopause-Stratopause-Mesopause Over Sub-Tropical Regions

    Science.gov (United States)

    Sharma, Som; Kumar, Prashant; Vaishnav, Rajesh; Jethva, Chintan; Bencherif, Hassan

    2018-03-01

    The transition regions in thermal structure viz. Tropopause, stratopause and mesopause play a vital role in the vertical coupling of the Earth's atmosphere. For the first time, inter-hemispheric characteristics of the transition regions over two subtropical regions are studied using temperature observations from the SABER onboard TIMED satellite and the ERA Interim reanalysis during year 2002 to 2015. Results show that tropopause height is higher over Reunion Island (21.11°S, 55.53°E) in the Southern Hemisphere (SH) as compared to Mt. Abu region (24.59°N, 72.70°E) in the Northern Hemisphere (NH). Temporal variation of tropopause temperature reveals a decreasing ( 4 K) trend from year 2002 to 2008 and beyond this, an increasing ( 1.5 K) trend is found in tropopause temperature. These features are reinforcing for Mesopause as compared to tropopause temperature. The SH shows stronger variations in Mesopause temperature ( 7 K) compared to NH during year 2002 to 2008. The occurrence frequency of mesopause and stratopause height shows that the maximum occurrence frequency ( 60%) of mesopause at 100 km in NH, while frequency is found to be 55% in the SH. Results show that stratopause (mesopause) is cooler (warmer) in NH as compared SH. Moreover, Lomb Scargle Periodogram and wavelet transform techniques are used to investigate the periodicity of mesopause, stratopause and tropopause temperatures and heights. Investigations revealed prominent annual oscillations in the tropopause and stratopause temperatures in both hemispheres. These findings will be of immense use for the vertical and inter-hemispheric atmospheric coupling studies.

  15. Which cause of diffuse peritonitis is the deadliest in the tropics? A retrospective analysis of 305 cases from the South-West Region of Cameroon.

    Science.gov (United States)

    Chichom-Mefire, Alain; Fon, Tabe Alain; Ngowe-Ngowe, Marcelin

    2016-01-01

    Acute diffuse peritonitis is a common surgical emergency worldwide and a major contributor to non-trauma related death toll. Its causes vary widely and are correlated with mortality. Community acquired peritonitis seems to play a major role and is frequently related to hollow viscus perforation. Data on the outcome of peritonitis in the tropics are scarce. The aim of this study is to analyze the impact of tropic latitude causes of diffuse peritonitis on morbidity and mortality. We retrospectively reviewed the records of 305 patients operated on for a diffuse peritonitis in two regional hospitals in the South-West Region of Cameroon over a 7 years period. The contributions of various causes of peritonitis to morbidity and mortality were analyzed. The diagnosis of diffuse peritonitis was suggested on clinical ground only in more than 93 % of cases. The most common causes of diffuse peritonitis included peptic ulcer perforation (n = 69), complications of acute appendicitis (n = 53) and spontaneous perforations of the terminal ileum (n = 43). A total of 142 complications were recorded in 96 patients (31.5 % complication rate). The most common complications included wound dehiscence, sepsis, prolonged paralytic ileus and multi-organ failure. Patients with typhoid perforation of the terminal ileum carried a significantly higher risk of developing a complication (p = 0.002). The overall mortality rate was 15.1 %. The most common cause of death was septic shock. Differential analysis of mortality of various causes of peritonitis indicated that the highest contributors to death toll were typhoid perforation of terminal ileum (34.7 % of deaths), post-operative peritonitis (19.5 %) and peptic ulcer perforation (15.2 %). The diagnosis of diffuse peritonitis can still rely on clinical assessment alone in the absence of sophisticated imaging tools. Peptic ulcer and typhoid perforations are still major contributors to death toll. Patients presenting with

  16. A Drone-based Tropical Forest Experiment to Estimate Vegetation Properties

    Science.gov (United States)

    Henke, D.

    2017-12-01

    In mid-latitudes, remote sensing technology is intensively used to monitor vegetation properties. However, in the tropics, high cloud-cover and saturation effects of vegetation indices (VI) hamper the reliability of vegetation parameters derived from satellite data. A drone experiment over the Barro Colorado Island (BCI), Panama, with high temporal repetition rates was conducted in spring 2017 to investigate the robustness and stability of remotely sensed vegetation parameters in tropical environments. For this purpose, three 10-day flight windows in February, March and April were selected and drone flights were repeated on daily intervals when weather conditions and equipment allowed it. In total, 18 days were recorded with two different optical cameras on sensefly's eBee drone: one red, green, blue (RGB) camera and one camera with near infra-red (NIR), green and blue channels. When possible, the data were acquired at the same time of day. Pix4D and Agisoft software were used to calculate the Normalized Difference VI (NDVI) and forest structure. In addition, leave samples were collected ones per month from 16 different plant species and the relative water content was measured as ground reference. Further data sources for the analysis are phenocam images (RGB & NIR) on BCI and satellite images of MODIS (NDVI; Enhanced VI EVI) and Sentinel-1 (radar backscatter). The attached figure illustrates the main data collected on BCI. Initial results suggest that the coefficient of determination (R2) is relatively high between ground samples and drone data, Sentinel-1 backscatter and MODIS EVI with R2 values ranging from 0.4 to 0.6; on the contrary, R2 values between ground measurements and MODIS NDVI or phenocam images are below 0.2. As the experiment took place mainly during dry season on BCI, cloud-cover rates are less dominate than during wet season. Under these conditions, MODIS EVI, which is less vulnerable to saturation effects, seems to be more reliable than MODIS

  17. Tropical Agro-Sciences

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    The Tropical Agro-Sciences Division has two functions: conduct research on the impact of air pollution on tropical agricultural and to provide training to UPR graduate students and visiting scientists. Since the reorientation of the Center's interests under ERDA, the Division has directed its research activities, with particular emphasis on the effects of atmospheric pollution on tropical agriculture in the Guayanilla-Penuelas region, which has a fossil-fuel power plant, petroleum refineries, and associated industries. This new area of research is important to ERDA because the knowledge gained regarding the effects of air pollution related to energy technology on the agricultural environment and productivity will be useful in planning future energy developments. Information about the potential harm of air pollutants to man through the food chain and about ways of alleviating their impact on agriculture are of practical importance. Studies of the mechanisms involved in pollution injury, protection, and tolerance are of basic significance

  18. Rock outcrops reduce temperature-induced stress for tropical conifer by decoupling regional climate in the semiarid environment.

    Science.gov (United States)

    Locosselli, Giuliano Maselli; Cardim, Ricardo Henrique; Ceccantini, Gregório

    2016-05-01

    We aimed to understand the effect of rock outcrops on the growth of Podocarpus lambertii within a microrefuge. Our hypothesis holds that the growth and survival of this species depend on the regional climate decoupling provided by rock outcrops. To test this hypothesis, we characterized the microclimate of (1) surrounding vegetation, (2) rock outcrop corridors, and (3) adjacencies. We assessed population structure by collecting data of specimen stem diameter and height. We also assessed differences between vegetation associated or not with outcrops using satellite imaging. For dendrochronological analyses, we sampled 42 individuals. Tree rings of 31 individuals were dated, and climate-growth relationships were tested. Rock outcrops produce a favorable microclimate by reducing average temperature by 4.9 °C and increasing average air humidity by 12 %. They also reduce the variability of atmospheric temperature by 42 % and air humidity by 20 % supporting a vegetation with higher leaf area index. Within this vegetation, specimen height was strongly constrained by the outcrop height. Although temperature and precipitation modulate this species growth, temperature-induced stress is the key limiting growth factor for this population of P. lambertii. We conclude that this species growth and survival depend on the presence of rock outcrops. These topography elements decouple regional climate in a favorable way for this species growth. However, these benefits are restricted to the areas sheltered by rock outcrops. Although this microrefuge supported P. lambertii growth so far, it is unclear whether this protection would be sufficient to withstand the stress of future climate changes.

  19. Integration of Satellite, Global Reanalysis Data and Macroscale Hydrological Model for Drought Assessment in Sub-Tropical Region of India

    Science.gov (United States)

    Pandey, V.; Srivastava, P. K.

    2018-04-01

    Change in soil moisture regime is highly relevant for agricultural drought, which can be best analyzed in terms of Soil Moisture Deficit Index (SMDI). A macroscale hydrological model Variable Infiltration Capacity (VIC) was used to simulate the hydro-climatological fluxes including evapotranspiration, runoff, and soil moisture storage to reconstruct the severity and duration of agricultural drought over semi-arid region of India. The simulations in VIC were performed at 0.25° spatial resolution by using a set of meteorological forcing data, soil parameters and Land Use Land Cover (LULC) and vegetation parameters. For calibration and validation, soil parameters obtained from National Bureau of Soil Survey and Land Use Planning (NBSSLUP) and ESA's Climate Change Initiative soil moisture (CCI-SM) data respectively. The analysis of results demonstrates that most of the study regions (> 80 %) especially for central northern part are affected by drought condition. The year 2001, 2002, 2007, 2008 and 2009 was highly affected by agricultural drought. Due to high average and maximum temperature, we observed higher soil evaporation that reduces the surface soil moisture significantly as well as the high topographic variations; coarse soil texture and moderate to high wind speed enhanced the drying upper soil moisture layer that incorporate higher negative SMDI over the study area. These findings can also facilitate the archetype in terms of daily time step data, lengths of the simulation period, various hydro-climatological outputs and use of reasonable hydrological model.

  20. INTEGRATION OF SATELLITE, GLOBAL REANALYSIS DATA AND MACROSCALE HYDROLOGICAL MODEL FOR DROUGHT ASSESSMENT IN SUB-TROPICAL REGION OF INDIA

    Directory of Open Access Journals (Sweden)

    V. Pandey

    2018-04-01

    Full Text Available Change in soil moisture regime is highly relevant for agricultural drought, which can be best analyzed in terms of Soil Moisture Deficit Index (SMDI. A macroscale hydrological model Variable Infiltration Capacity (VIC was used to simulate the hydro-climatological fluxes including evapotranspiration, runoff, and soil moisture storage to reconstruct the severity and duration of agricultural drought over semi-arid region of India. The simulations in VIC were performed at 0.25° spatial resolution by using a set of meteorological forcing data, soil parameters and Land Use Land Cover (LULC and vegetation parameters. For calibration and validation, soil parameters obtained from National Bureau of Soil Survey and Land Use Planning (NBSSLUP and ESA's Climate Change Initiative soil moisture (CCI-SM data respectively. The analysis of results demonstrates that most of the study regions (> 80 % especially for central northern part are affected by drought condition. The year 2001, 2002, 2007, 2008 and 2009 was highly affected by agricultural drought. Due to high average and maximum temperature, we observed higher soil evaporation that reduces the surface soil moisture significantly as well as the high topographic variations; coarse soil texture and moderate to high wind speed enhanced the drying upper soil moisture layer that incorporate higher negative SMDI over the study area. These findings can also facilitate the archetype in terms of daily time step data, lengths of the simulation period, various hydro-climatological outputs and use of reasonable hydrological model.

  1. Tropical Peatland Geomorphology and Hydrology

    Science.gov (United States)

    Cobb, A.; Harvey, C. F.

    2017-12-01

    Tropical peatlands cover many low-lying areas in the tropics. In tropical peatlands, a feedback between hydrology, landscape morphology, and carbon storage causes waterlogged organic matter to accumulate into gently mounded land forms called peat domes over thousands of years. Peat domes have a stable morphology in which peat production is balanced by loss and net precipitation is balanced by lateral flow, creating a link between peatland morphology, rainfall patterns and drainage networks. We show how landscape morphology can be used to make inferences about hydrologic processes in tropical peatlands. In particular, we show that approaches using simple storage-discharge relationships for catchments are especially well suited to tropical peatlands, allowing river forecasting based on peatland morphology in catchments with tropical peatland subcatchments.

  2. Tropical cyclone losses in the USA and the impact of climate change - A trend analysis based on data from a new approach to adjusting storm losses

    International Nuclear Information System (INIS)

    Schmidt, Silvio; Kemfert, Claudia; Hoeppe, Peter

    2009-01-01

    Economic losses caused by tropical cyclones have increased dramatically. Historical changes in losses are a result of meteorological factors (changes in the incidence of severe cyclones, whether due to natural climate variability or as a result of human activity) and socio-economic factors (increased prosperity and a greater tendency for people to settle in exposed areas). This paper aims to isolate the socio-economic effects and ascertain the potential impact of climate change on this trend. Storm losses for the period 1950-2005 have been adjusted to the value of capital stock in 2005 so that any remaining trend cannot be ascribed to socio-economic developments. For this, we introduce a new approach to adjusting losses based on the change in capital stock at risk. Storm losses are mainly determined by the intensity of the storm and the material assets, such as property and infrastructure, located in the region affected. We therefore adjust the losses to exclude increases in the capital stock of the affected region. No trend is found for the period 1950-2005 as a whole. In the period 1971-2005, since the beginning of a trend towards increased intense cyclone activity, losses excluding socio-economic effects show an annual increase of 4% per annum. This increase must therefore be at least due to the impact of natural climate variability but, more likely than not, also due to anthropogenic forcings.

  3. Maximum covariance analysis to identify intraseasonal oscillations over tropical Brazil

    Science.gov (United States)

    Barreto, Naurinete J. C.; Mesquita, Michel d. S.; Mendes, David; Spyrides, Maria H. C.; Pedra, George U.; Lucio, Paulo S.

    2017-09-01

    A reliable prognosis of extreme precipitation events in the tropics is arguably challenging to obtain due to the interaction of meteorological systems at various time scales. A pivotal component of the global climate variability is the so-called intraseasonal oscillations, phenomena that occur between 20 and 100 days. The Madden-Julian Oscillation (MJO), which is directly related to the modulation of convective precipitation in the equatorial belt, is considered the primary oscillation in the tropical region. The aim of this study is to diagnose the connection between the MJO signal and the regional intraseasonal rainfall variability over tropical Brazil. This is achieved through the development of an index called Multivariate Intraseasonal Index for Tropical Brazil (MITB). This index is based on Maximum Covariance Analysis (MCA) applied to the filtered daily anomalies of rainfall data over tropical Brazil against a group of covariates consisting of: outgoing longwave radiation and the zonal component u of the wind at 850 and 200 hPa. The first two MCA modes, which were used to create the { MITB}_1 and { MITB}_2 indices, represent 65 and 16 % of the explained variance, respectively. The combined multivariate index was able to satisfactorily represent the pattern of intraseasonal variability over tropical Brazil, showing that there are periods of activation and inhibition of precipitation connected with the pattern of MJO propagation. The MITB index could potentially be used as a diagnostic tool for intraseasonal forecasting.

  4. The tropospheric biennial oscillation defined by a biennial mode of sea surface temperature and its impact on the atmospheric circulation and precipitation in the tropical eastern Indo-western Pacific region

    Science.gov (United States)

    Kim, Jinju; Kim, Kwang-Yul

    2016-10-01

    Temporal and spatial patterns of anomalous atmospheric circulation and precipitation over the Indo-Pacific region are analyzed in conjunction with the Tropospheric Biennial Oscillation as represented by the biennial mode of sea surface temperature anomalies (SSTA). The biennial components of key variables are identified independently of other variability via CSEOF analysis. Then, its impact on the Asian-Australian monsoon is examined. The biennial mode exhibits a seasonally distinctive atmospheric response over the tropical eastern Indo-western Pacific (EIWP) region (90°-150°E, 20°S-20°N). In boreal summer, local meridional circulation is a distinguishing characteristic over the tropical EIWP region, whereas a meridionally expanded branch of intensified zonal circulation develops in austral summer. Temporally varying evolution and distinct timing of SSTA phase transition in the Indian and Pacific Oceans is considered a main factor for this variation of circulation in the tropical EIWP region. The impact of the biennial mode is not the same between the two seasons, with different impacts over ocean areas in Asian monsoon and Australian monsoon regions.

  5. Airborne lidar-based estimates of tropical forest structure in complex terrain: opportunities and trade-offs for REDD+

    Science.gov (United States)

    Leitold, Veronika; Keller, Michael; Morton, Douglas C; Cook, Bruce D; Shimabukuro, Yosio E

    2015-12-01

    Carbon stocks and fluxes in tropical forests remain large sources of uncertainty in the global carbon budget. Airborne lidar remote sensing is a powerful tool for estimating aboveground biomass, provided that lidar measurements penetrate dense forest vegetation to generate accurate estimates of surface topography and canopy heights. Tropical forest areas with complex topography present a challenge for lidar remote sensing. We compared digital terrain models (DTM) derived from airborne lidar data from a mountainous region of the Atlantic Forest in Brazil to 35 ground control points measured with survey grade GNSS receivers. The terrain model generated from full-density (~20 returns m -2 ) data was highly accurate (mean signed error of 0.19 ± 0.97 m), while those derived from reduced-density datasets (8 m -2 , 4 m -2 , 2 m -2 and 1 m -2 ) were increasingly less accurate. Canopy heights calculated from reduced-density lidar data declined as data density decreased due to the inability to accurately model the terrain surface. For lidar return densities below 4 m -2 , the bias in height estimates translated into errors of 80-125 Mg ha -1 in predicted aboveground biomass. Given the growing emphasis on the use of airborne lidar for forest management, carbon monitoring, and conservation efforts, the results of this study highlight the importance of careful survey planning and consistent sampling for accurate quantification of aboveground biomass stocks and dynamics. Approaches that rely primarily on canopy height to estimate aboveground biomass are sensitive to DTM errors from variability in lidar sampling density.

  6. Simulation of river plume behaviors in a tropical region: Case study of the Upper Gulf of Thailand

    Science.gov (United States)

    Yu, Xiaojie; Guo, Xinyu; Morimoto, Akihiko; Buranapratheprat, Anukul

    2018-02-01

    River plumes are a general phenomenon in coastal regions. Most previous studies focus on river plumes in middle and high latitudes with few studies examining those in low latitude regions. Here, we apply a numerical model to the Upper Gulf of Thailand (UGoT) to examine a river plume in low latitudes. Consistent with observational data, the modeled plume has seasonal variation dependent on monsoon conditions. During southwesterly monsoons, the plume extends northeastward to the head of the gulf; during northeasterly monsoons, it extends southwestward to the mouth of the gulf. To examine the effects of latitude, wind and river discharge on the river plume, we designed several numerical experiments. Using a middle latitude for the UGoT, the bulge close to the river mouth becomes smaller, the downstream current flows closer to the coast, and the salinity in the northern UGoT becomes lower. The reduction in the size of the bulge is consistent with the relationship between the offshore distance of a bulge and the Coriolis parameter. Momentum balance of the coastal current is maintained by advection, the Coriolis force, pressure gradient and internal stresses in both low and middle latitudes, with the Coriolis force and pressure gradient enlarged in the middle latitude. The larger pressure gradient in the middle latitude is induced by more offshore freshwater flowing with the coastal current, which induces lower salinity. The influence of wind on the river plume not only has the advection effects of changing the surface current direction and increasing the surface current speed, but also decreases the current speed due to enhanced vertical mixing. Changes in river discharge influence stratification in the UGoT but have little effect on the behavior of the river plume.

  7. Changes in Eocene-Miocene shallow marine carbonate factories along the tropical SE Circum-Caribbean responded to major regional and global environmental and tectonic events

    Science.gov (United States)

    Silva-Tamayo, Juan Carlos

    2015-04-01

    Changes in the factory of Cenozoic tropical marine carbonates have been for long attributed to major variations on climatic and environmental conditions. Although important changes on the factories of Cenozoic Caribbean carbonates seem to have followed global climatic and environmental changes, the regional impact of such changes on the factories of shallow marine carbonate along the Caribbean is not well established. Moreover, the influence of transpressional tectonics on the occurrence, distribution and stratigraphy of shallow marine carbonate factories along this area is far from being well understood. Here we report detailed stratigraphic, petrographic and Sr-isotope chemostratigraphic information of several Eocene-Miocene carbonate successions deposited along the equatorial/tropical SE Circum-Caribbean (Colombia and Panama) from which we further assess the influence of changing environmental conditions, transtentional tectonics and sea level change on the development of the shallow marine carbonate factories. Our results suggest that during the Eocene-early Oligocene interval, a period of predominant high atmospheric pCO2, coralline algae constitute the principal carbonate builders of shallow marine carbonate successions along the SE Circum-Caribbean. Detailed stratigraphic and paragenetic analyses suggest the developed of laterally continuous red algae calcareous build-ups along outer-rimmed carbonate platforms. The predominance of coralline red algae over corals on the shallow marine carbonate factories was likely related to high sea surface temperatures and high turbidity. The occurrence of such build-ups was likely controlled by pronounce changes in the basin paleotopography, i.e. the occurrence of basement highs and lows, resulting from local transpressional tectonics. The occurrence of these calcareous red algae dominated factories was also controlled by diachronic opening of different sedimentary basins along the SE Circum Caribbean resulting from

  8. Seasonal and spatial distribution of Bacterioplankton in a fluvial-lagunar system of a tropical region: density, biomass, cellular volume and morphologic variation

    Directory of Open Access Journals (Sweden)

    Magnólia Fernandes Florêncio de Araújo

    2008-02-01

    Full Text Available The temporal and spatial fluctuations of Bacterioplankton in a fluvial-lagunar system of a tropical region (Pitimbu River and Jiqui Lake, RN were studied during the dry and the rainy periods. The bacterial abundance varied from 2.67 to 5.1 Cells10(7mL-1 and did not show a typical temporal variation, presenting only small oscillations between the rainy and the dry periods. The bacterial biomass varied from 123 µgC L-1 to 269 µgC L-1 in the sampling sites and the average cellular volume varied from 0.12 to 0.54µm³, showing a predominance of the rods. The temperature showed a positive correlation with the cellular volume of the rods (R=0.55; p=0.02 and vibrio (R=0.53; p=0.03. Significant spatial differences of biomass (Mann Whitney: p=0.01 and cellular volume of the morphotypes (Mann Whitney: p=0.003 were found between the sampling sites. The strong positive correlations of the water temperature and oxygen with bacterioplankton showed a probable high bacterial activity in this system.A variação temporal e espacial do bacterioplâncton em um sistema fluvial-lagunar de região tropical foi estudada em períodos seco e chuvoso. As médias da abundância bacteriana variaram de 2,67 a 5,1 x 10(7 e não exibiram uma variação temporal marcante, tendo apresentado apenas pequenas oscilações entre os períodos chuvoso e seco. A biomassa bacteriana variou de 123 µg C L-1 a 269 µg C L-1 entre os locais de coleta e o volume celular médio de 0,12µm³ a 0,54µm³, ocorrendo predominância de bacilos. A temperatura mostrou correlação positiva com o volume celular de bacilos (R=0,55; p=0,02 e de vibriões (R=0,53; p=0,03. Foram encontradas diferenças espaciais significativas de biomassa (Mann Whitney: p=0,01 e volume celular dos morfotipos (Mann Whitney: p= 0,003, entre os locais de coleta. As fortes correlações positivas da temperatura da água e do oxigênio, com o bacterioplâncton, são sugestivas de uma provavelmente elevada atividade

  9. Southern Hemisphere Additional Ozonesondes (SHADOZ) Ozone Climatology (2005-2009): Tropospheric and Tropical Tropopause Layer (TTL) Profiles with Comparisons to Omi-based Ozone Products

    Science.gov (United States)

    Thompson, Anne M.; Miller, Sonya K.; Tilmes, Simone; Kollonige, Debra W.; Witte, Jacquelyn C.; Oltmans, Samuel J.; Johnson, Brian J.; Fujiwara, Masatomo; Schmidlin, F. J.; Coetzee, G. J. R.; hide

    2012-01-01

    We present a regional and seasonal climatology of SHADOZ ozone profiles in the troposphere and tropical tropopause layer (TTL) based on measurements taken during the first five years of Aura, 2005-2009, when new stations joined the network at Hanoi, Vietnam; Hilo, Hawaii; Alajuela Heredia, Costa Rica; Cotonou, Benin. In all, 15 stations operated during that period. A west-to-east progression of decreasing convective influence and increasing pollution leads to distinct tropospheric ozone profiles in three regions: (1) western Pacific eastern Indian Ocean; (2) equatorial Americas (San Cristobal, Alajuela, Paramaribo); (3) Atlantic and Africa. Comparisons in total ozone column from soundings, the Ozone Monitoring Instrument (OMI, on Aura, 2004-) satellite and ground-based instrumentation are presented. Most stations show better agreement with OMI than they did for EPTOMS comparisons (1998-2004; Earth-ProbeTotal Ozone Mapping Spectrometer), partly due to a revised above-burst ozone climatology. Possible station biases in the stratospheric segment of the ozone measurement noted in the first 7 years of SHADOZ ozone profiles are re-examined. High stratospheric bias observed during the TOMS period appears to persist at one station. Comparisons of SHADOZ tropospheric ozone and the daily Trajectory-enhanced Tropospheric Ozone Residual (TTOR) product (based on OMIMLS) show that the satellite-derived column amount averages 25 low. Correlations between TTOR and the SHADOZ sondes are quite good (typical r2 0.5-0.8), however, which may account for why some published residual-based OMI products capture tropospheric interannual variability fairly realistically. On the other hand, no clear explanations emerge for why TTOR-sonde discrepancies vary over a wide range at most SHADOZ sites.

  10. Effects of a wind farm installation on the understory bat community of a highly biodiverse tropical region in Mexico

    Directory of Open Access Journals (Sweden)

    Miguel Briones-Salas

    2017-06-01

    Full Text Available Wind energy has rapidly become an important alternative among renewable energies, and it is generally considered clean. However, little is known about its impact at the level of ecological communities, especially in biodiversity hotspots. The Isthmus of Tehuantepec is a highly biodiverse region in Mesoamerica, and has the highest potential for generating wind energy in Mexico. To assess the effects of installing a wind farm on the understory bat community in a landscape of fragmented habitat, we assessed its diversity and composition over four stages of installation (site preparation, construction, and two stages of operation. We captured 919 bats belonging to 22 species. Species richness, functional diversity and phylogenetic diversity decreased during construction and the first stage of operation. However, these components of biodiversity increased during the second stage of operation, and species composition began to resemble that of the site preparation stage. No species considered as sensitive to disturbance was recorded at any stage. This is the first study to reveal the diversity of a Neotropical bat community after wind turbines begin to operate.

  11. Flash Flood Prediction by Coupling KINEROS2 and HEC-RAS Models for Tropical Regions of Northern Vietnam

    Directory of Open Access Journals (Sweden)

    Hong Quang Nguyen

    2015-11-01

    Full Text Available Northern Vietnam is a region prone to heavy flash flooding events. These often have devastating effects on the environment, cause economic damage and, in the worst case scenario, cost human lives. As their frequency and severity are likely to increase in the future, procedures have to be established to cope with this threat. As the prediction of potential flash floods represents one crucial element in this circumstance, we will present an approach that combines the two models KINEROS2 and HEC-RAS in order to accurately predict their occurrence. We used a documented event on 23 June 2011 in the Nam Khat and the larger adjacent Nam Kim watershed to calibrate the coupled model approach. Afterward, we evaluated the performance of the coupled models in predicting flow velocity (FV, water levels (WL, discharge (Q and streamflow power (P during the 3–5 days following the event, using two different precipitation datasets from the global spectral model (GSM and the high resolution model (HRM. Our results show that the estimated Q and WL closely matched observed data with a Nash–Sutcliffe simulation efficiency coefficient (NSE of around 0.93 and a coefficient of determination (R2 at above 0.96. The resulting analyses reveal strong relationships between river geometry and FV, WL and P. Although there were some minor errors in forecast results, the model-predicted Q and WL corresponded well to the gauged data.

  12. Effects of a wind farm installation on the understory bat community of a highly biodiverse tropical region in Mexico

    Science.gov (United States)

    Lavariega, Mario C.; Moreno, Claudia E.

    2017-01-01

    Wind energy has rapidly become an important alternative among renewable energies, and it is generally considered clean. However, little is known about its impact at the level of ecological communities, especially in biodiversity hotspots. The Isthmus of Tehuantepec is a highly biodiverse region in Mesoamerica, and has the highest potential for generating wind energy in Mexico. To assess the effects of installing a wind farm on the understory bat community in a landscape of fragmented habitat, we assessed its diversity and composition over four stages of installation (site preparation, construction, and two stages of operation). We captured 919 bats belonging to 22 species. Species richness, functional diversity and phylogenetic diversity decreased during construction and the first stage of operation. However, these components of biodiversity increased during the second stage of operation, and species composition began to resemble that of the site preparation stage. No species considered as sensitive to disturbance was recorded at any stage. This is the first study to reveal the diversity of a Neotropical bat community after wind turbines begin to operate. PMID:28630802

  13. Effects of a wind farm installation on the understory bat community of a highly biodiverse tropical region in Mexico.

    Science.gov (United States)

    Briones-Salas, Miguel; Lavariega, Mario C; Moreno, Claudia E

    2017-01-01

    Wind energy has rapidly become an important alternative among renewable energies, and it is generally considered clean. However, little is known about its impact at the level of ecological communities, especially in biodiversity hotspots. The Isthmus of Tehuantepec is a highly biodiverse region in Mesoamerica, and has the highest potential for generating wind energy in Mexico. To assess the effects of installing a wind farm on the understory bat community in a landscape of fragmented habitat, we assessed its diversity and composition over four stages of installation (site preparation, construction, and two stages of operation). We captured 919 bats belonging to 22 species. Species richness, functional diversity and phylogenetic diversity decreased during construction and the first stage of operation. However, these components of biodiversity increased during the second stage of operation, and species composition began to resemble that of the site preparation stage. No species considered as sensitive to disturbance was recorded at any stage. This is the first study to reveal the diversity of a Neotropical bat community after wind turbines begin to operate.

  14. Parameterization of the middle and upper tropospheric water vapor from ATOVS observations over a tropical climate region

    Science.gov (United States)

    Makama, Ezekiel Kaura; Lim, Hwee San; Abdullah, Khiruddin

    2018-01-01

    Precipitable water vapor (PWV) is a highly variable, but important greenhouse gas that regulates the radiation budget of the earth. Its variability in time and space makes it difficult to quantify. Knowledge of its vertical distribution, in particular, is crucial for many reasons. In this study, empirical relationships between isobaric layers of PWV over Peninsular Malaysia are examined. Analysis of variance (ANOVA) technique on Advanced Television and Infrared Observation Satellite Operational Vertical Sounder (ATOVS) observations, from 2005 to 2011, has been used to propose a relationship of the form, W=α(WL)β for the middle (MW) and upper (UW) layers PWV. W is either MW or UW with α and β as regression coefficients, which are functions of latitude. Coefficients of determination (R2) and root mean square error (RMSE) of respective values between 0.75-0.86 and 1.65-2.38 mm, across the zones, were obtained for both the MW and UW predictions, with a mean bias (MB) below ±1 mm.The predicted and observed PWV presented a better agreement northerly. Initial predictability test for each model was done on two independent data sets: ATOVS (2012-2015), and radiosonde (2010-2011) at Penang, Kuantan and Sepang stations, with very good outcomes. The results of the tests revealed remarkable performances, when compared with two previously reported models. The inclusion of variable regression coefficients, and the utilization of satellite-derived data, which provide soundings of data-void regions between radiosonde networks, proved to have optimized the results.

  15. Tropical forest fragmentation affects floral visitors but not the structure of individual-based palm-pollinator networks.

    Science.gov (United States)

    Dáttilo, Wesley; Aguirre, Armando; Quesada, Mauricio; Dirzo, Rodolfo

    2015-01-01

    Despite increasing knowledge about the effects of habitat loss on pollinators in natural landscapes, information is very limited regarding the underlying mechanisms of forest fragmentation affecting plant-pollinator interactions in such landscapes. Here, we used a network approach to describe the effects of forest fragmentation on the patterns of interactions involving the understory dominant palm Astrocaryum mexicanum (Arecaceae) and its floral visitors (including both effective and non-effective pollinators) at the individual level in a Mexican tropical rainforest landscape. Specifically, we asked: (i) Does fragment size affect the structure of individual-based plant-pollinator networks? (ii) Does the core of highly interacting visitor species change along the fragmentation size gradient? (iii) Does forest fragment size influence the abundance of effective pollinators of A. mexicanum? We found that fragment size did not affect the topological structure of the individual-based palm-pollinator network. Furthermore, while the composition of peripheral non-effective pollinators changed depending on fragment size, effective core generalist species of pollinators remained stable. We also observed that both abundance and variance of effective pollinators of male and female flowers of A. mexicanum increased with forest fragment size. These findings indicate that the presence of effective pollinators in the core of all forest fragments could keep the network structure stable along the gradient of forest fragmentation. In addition, pollination of A. mexicanum could be more effective in larger fragments, since the greater abundance of pollinators in these fragments may increase the amount of pollen and diversity of pollen donors between flowers of individual plants. Given the prevalence of fragmentation in tropical ecosystems, our results indicate that the current patterns of land use will have consequences on the underlying mechanisms of pollination in remnant forests.

  16. Tropical forest fragmentation affects floral visitors but not the structure of individual-based palm-pollinator networks.

    Directory of Open Access Journals (Sweden)

    Wesley Dáttilo

    Full Text Available Despite increasing knowledge about the effects of habitat loss on pollinators in natural landscapes, information is very limited regarding the underlying mechanisms of forest fragmentation affecting plant-pollinator interactions in such landscapes. Here, we used a network approach to describe the effects of forest fragmentation on the patterns of interactions involving the understory dominant palm Astrocaryum mexicanum (Arecaceae and its floral visitors (including both effective and non-effective pollinators at the individual level in a Mexican tropical rainforest landscape. Specifically, we asked: (i Does fragment size affect the structure of individual-based plant-pollinator networks? (ii Does the core of highly interacting visitor species change along the fragmentation size gradient? (iii Does forest fragment size influence the abundance of effective pollinators of A. mexicanum? We found that fragment size did not affect the topological structure of the individual-based palm-pollinator network. Furthermore, while the composition of peripheral non-effective pollinators changed depending on fragment size, effective core generalist species of pollinators remained stable. We also observed that both abundance and variance of effective pollinators of male and female flowers of A. mexicanum increased with forest fragment size. These findings indicate that the presence of effective pollinators in the core of all forest fragments could keep the network structure stable along the gradient of forest fragmentation. In addition, pollination of A. mexicanum could be more effective in larger fragments, since the greater abundance of pollinators in these fragments may increase the amount of pollen and diversity of pollen donors between flowers of individual plants. Given the prevalence of fragmentation in tropical ecosystems, our results indicate that the current patterns of land use will have consequences on the underlying mechanisms of pollination in

  17. Regional Economic Development Strategy Based Agro-Industries in Key Region Kandangan South of Kalimantan

    Directory of Open Access Journals (Sweden)

    Dewi Siska

    2016-06-01

    Full Text Available Agroindustry has become the main pillar in South Kalimantan development, it can be found in RPJPD 2005-2025. Kandangan mainstay region as one of three leading regions in South Kalimantan which potentially improved to push economy growth through agriculture based industry activity (agroindustry. The concept of agroindustry a side is expected to drive economic growth as well as to realize the equitable distribution of income. This research aims to: (1 identify to economic development of the region in Kandangan mainstay regions, (2 identify the main commodity, (3 identify means of supporting agroindustry, and (4 formulating development strategies based agroindustry region. Entropy analysis shows the development of the economy sufficiently developed in Kandangan mainstay region dominated by the agricultural sector, namely food crops subsector. LQ an SSA analysis shows corn and rice crops become competitive commodities. There are only few of supporting infrastructure agroindustry activities. Strategy formulation in the research is the improvement of infrastructure or infrastructure that can facilitate inter regional connectivity in the region mainstay Kandangan and the government as the leading actor agroindustry development.

  18. Seasonal behaviour of tidal inlets in a tropical monsoon area

    NARCIS (Netherlands)

    Lam, N.T.; Stive, M.J.F.; Verhagen, H.J.; Wang, Z.B.

    2008-01-01

    Morphodynamics of a tidal inlet system on a micro-tidal coast in a tropical monsoon influenced region is modelled and discussed. Influences of river flow and wave climate on the inlet morphology are investigated with the aid of process-based state-of-the-art numerical models. Seasonal and episodic

  19. A Trust-region-based Sequential Quadratic Programming Algorithm

    DEFF Research Database (Denmark)

    Henriksen, Lars Christian; Poulsen, Niels Kjølstad

    This technical note documents the trust-region-based sequential quadratic programming algorithm used in other works by the authors. The algorithm seeks to minimize a convex nonlinear cost function subject to linear inequalty constraints and nonlinear equality constraints.......This technical note documents the trust-region-based sequential quadratic programming algorithm used in other works by the authors. The algorithm seeks to minimize a convex nonlinear cost function subject to linear inequalty constraints and nonlinear equality constraints....

  20. tropiTree: An NGS-Based EST-SSR Resource for 24 Tropical Tree Species

    Science.gov (United States)

    Russell, Joanne R.; Hedley, Peter E.; Cardle, Linda; Dancey, Siobhan; Morris, Jenny; Booth, Allan; Odee, David; Mwaura, Lucy; Omondi, William; Angaine, Peter; Machua, Joseph; Muchugi, Alice; Milne, Iain; Kindt, Roeland; Jamnadass, Ramni; Dawson, Ian K.

    2014-01-01

    The development of genetic tools for non-model organisms has been hampered by cost, but advances in next-generation sequencing (NGS) have created new opportunities. In ecological research, this raises the prospect for developing molecular markers to simultaneously study important genetic processes such as gene flow in multiple non-model plant species within complex natural and anthropogenic landscapes. Here, we report the use of bar-coded multiplexed paired-end Illumina NGS for the de novo development of expressed sequence tag-derived simple sequence repeat (EST-SSR) markers at low cost for a range of 24 tree species. Each chosen tree species is important in complex tropical agroforestry systems where little is currently known about many genetic processes. An average of more than 5,000 EST-SSRs was identified for each of the 24 sequenced species, whereas prior to analysis 20 of the species had fewer than 100 nucleotide sequence citations. To make results available to potential users in a suitable format, we have developed an open-access, interactive online database, tropiTree (http://bioinf.hutton.ac.uk/tropiTree), which has a range of visualisation and search facilities, and which is a model for the efficient presentation and application of NGS data. PMID:25025376

  1. Analyses of the influencing factors of soil microbial functional gene diversity in tropical rainforest based on GeoChip 5.0.

    Science.gov (United States)

    Cong, Jing; Liu, Xueduan; Lu, Hui; Xu, Han; Li, Yide; Deng, Ye; Li, Diqiang; Zhang, Yuguang

    2015-09-01

    To examine soil microbial functional gene diversity and causative factors in tropical rainforests, we used a microarray-based metagenomic tool named GeoChip 5.0 to profile it. We found that high microbial functional gene diversity and different soil microbial metabolic potential for biogeochemical processes were considered to exist in tropical rainforest. Soil available nitrogen was the most associated with soil microbial functional gene structure. Here, we mainly describe the experiment design, the data processing, and soil biogeochemical analyses attached to the study in details, which could be published on BMC microbiology Journal in 2015, whose raw data have been deposited in NCBI's Gene Expression Omnibus (accession number GSE69171).

  2. GHRSST Level 2P Regional Subskin Sea Surface Temperature from the Tropical Rainfall Mapping Mission (TRMM) Microwave Imager (TMI) for the Atlantic Ocean (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) is a well calibrated passive microwave radiometer, similar to SSM/I, that contains lower...

  3. Measurements of the streaming potential of clay soils from tropical and subtropical regions using self-made apparatus.

    Science.gov (United States)

    Li, Zhong-Yi; Li, Jiu-Yu; Liu, Yuan; Xu, Ren-Kou

    2014-09-01

    The streaming potential has been wildly used in charged parallel plates, capillaries, and porous media. However, there have been few studies involving the ζ potential of clay soils based on streaming potential measurements. A laboratory apparatus was developed in this study to measure the streaming potential (ΔE) of bulk clay soils' coupling coefficient (C) and cell resistance (R) of saturated granular soil samples. Excellent linearity of ΔE versus liquid pressure (ΔP) ensured the validity of measurements. The obtained parameters of C and R can be used to calculate the ζ potential of bulk soils. The results indicated that the ζ potentials measured by streaming potential method were significantly correlated with the ζ potentials of soil colloids determined by electrophoresis (r (2) = 0.960**). Therefore, the streaming potential method can be used to study the ζ potentials of bulk clay soils. The absolute values of the ζ potentials of four soils followed the order: Ultisol from Jiangxi > Ultisol from Anhui > Oxisol from Guangdong > Oxisol from Hainan, and this was consistent with the cation exchange capacities of these soils. The type and concentration of electrolytes affected soil ζ potentials. The ζ potential became less negative with increased electrolyte concentration. The ζ potentials were more negative in monovalent than in divalent cationic electrolyte solutions because more divalent cations were distributed in the shear plane of the diffuse layer as counter-cations on the soil surfaces than monovalent cations at the same electrolyte concentration.

  4. Nutritional value and proteases of Lentinus citrinus produced by solid state fermentation of lignocellulosic waste from tropical region

    Directory of Open Access Journals (Sweden)

    Ana Rita Gaia Machado

    2016-09-01

    Full Text Available This paper examined the growth and yield performance of Lentinus citrinus on cupuaçu exocarp (Theobroma grandiflorum mixed with litter (CE + LI or rice bran (Oryza sativa (CE + RB in the ratio of 2:1 (800 g:200 g to investigate the nutritional composition and proteolytic potential of the fruiting body produced. Significance values of yield were determined on substrate combinations. In CE + LI the biological efficiency of the mushrooms was 93.5% and the content of fat (4.5%, fiber (11.0%, protein (27.0% and amino acids were higher when compared with CE + RB. Among the amino acids, the amount of glutamic acid, aspartic acid, alanine, arginine and leucine was high. The biological efficiency on CE + RB reduced to 84.2% and based on the nutritional value, carbohydrates (53.59%, energy (324.33 kcal and minerals such as zinc, iron, copper, potassium and phosphorus were higher in this substrate combination. Protease activity from fruiting body was significant in CE + LI (463.55 U/mL. This protease showed an optimal activity at 50 °C in neutral and alkaline pH with maximum stability at 30 °C at alkaline pH. This is the first report of L. citrinus fruiting body nutritional composition with potential for human food and application in industrial processes.

  5. Continued Analysis on Multiscale Aspects of Tropical Cyclone Formation, Structure Change and Predictability in the Western North Pacific Region as Part of the TCS08 DRI

    Science.gov (United States)

    2012-09-30

    Atmospheric Administration. The published paper was entitled “Structure of the Eye and Eyewall of Hurricane Hugo (1989) and was published in Mon. Wea. Rev., 136, 1237-1259. ...developments in tropical cyclone intensification theory A new paradigm of tropical cyclone intensification and hurricane boundary layer dynamics has been... Hurricane Rita (2005) show strong support for the second spin-up mechanism in the concentric eyewall lifecycle. Didlake and Houze (2011) found a

  6. Which cause of diffuse peritonitis is the deadliest in the tropics? A retrospective analysis of 305 cases from the South-West Region of Cameroon

    OpenAIRE

    Chichom-Mefire, Alain; Fon, Tabe Alain; Ngowe-Ngowe, Marcelin

    2016-01-01

    Background Acute diffuse peritonitis is a common surgical emergency worldwide and a major contributor to non-trauma related death toll. Its causes vary widely and are correlated with mortality. Community acquired peritonitis seems to play a major role and is frequently related to hollow viscus perforation. Data on the outcome of peritonitis in the tropics are scarce. The aim of this study is to analyze the impact of tropic latitude causes of diffuse peritonitis on morbidity and mortality. Met...

  7. Airborne lidar-based estimates of tropical forest structure in complex terrain: opportunities and trade-offs for REDD+

    Science.gov (United States)

    Veronika Leitold; Michael Keller; Douglas C Morton; Bruce D Cook; Yosio E Shimabukuro

    2015-01-01

    Background: Carbon stocks and fluxes in tropical forests remain large sources of uncertainty in the global carbon budget. Airborne lidar remote sensing is a powerful tool for estimating aboveground biomass, provided that lidar measurements penetrate dense forest vegetation to generate accurate estimates of surface topography and canopy heights. Tropical forest areas...

  8. The effects of the insecticide lambda-Cyhalothrin on the earthworm Eisenia fetida under experimental conditions of tropical and temperate regions.

    Science.gov (United States)

    Garcia, Marcos; Scheffczyk, Adam; Garcia, Terezinha; Römbke, Jörg

    2011-02-01

    Plant Protection Products can affect soil organisms and thus might have negative impacts on soil functions. Little research has been performed on their impact on tropical soils. Therefore, the effects of the insecticide lambda-Cyhalothrin on earthworms were evaluated in acute and chronic laboratory tests modified for tropical conditions, i.e. at selected temperatures (20 and 28°C) and with two strains (temperate and tropical) of the compost worm Eisenia fetida. The insecticide was spiked in two natural soils, in OECD artificial soil and a newly developed tropical artificial soil. The effects of lambda-Cyhalothrin did rarely vary in the same soil at tropical (LC50: 68.5-229 mg a.i./kg dry weight (DW); EC50: 54.2-60.2 mg a.i./kg DW) and temperate (LC50: 99.8-140 mg a.i./kg DW; EC50: 37.4-44.5 mg a.i./kg DW) temperatures. In tests with tropical soils and high temperature, effect values differed by up to a factor of ten. Copyright © 2010 Elsevier Ltd. All rights reserved.

  9. Prediction of monthly rainfall on homogeneous monsoon regions of India based on large scale circulation patterns using Genetic Programming

    Science.gov (United States)

    Kashid, Satishkumar S.; Maity, Rajib

    2012-08-01

    SummaryPrediction of Indian Summer Monsoon Rainfall (ISMR) is of vital importance for Indian economy, and it has been remained a great challenge for hydro-meteorologists due to inherent complexities in the climatic systems. The Large-scale atmospheric circulation patterns from tropical Pacific Ocean (ENSO) and those from tropical Indian Ocean (EQUINOO) are established to influence the Indian Summer Monsoon Rainfall. The information of these two large scale atmospheric circulation patterns in terms of their indices is used to model the complex relationship between Indian Summer Monsoon Rainfall and the ENSO as well as EQUINOO indices. However, extracting the signal from such large-scale indices for modeling such complex systems is significantly difficult. Rainfall predictions have been done for 'All India' as one unit, as well as for five 'homogeneous monsoon regions of India', defined by Indian Institute of Tropical Meteorology. Recent 'Artificial Intelligence' tool 'Genetic Programming' (GP) has been employed for modeling such problem. The Genetic Programming approach is found to capture the complex relationship between the monthly Indian Summer Monsoon Rainfall and large scale atmospheric circulation pattern indices - ENSO and EQUINOO. Research findings of this study indicate that GP-derived monthly rainfall forecasting models, that use large-scale atmospheric circulation information are successful in prediction of All India Summer Monsoon Rainfall with correlation coefficient as good as 0.866, which may appears attractive for such a complex system. A separate analysis is carried out for All India Summer Monsoon rainfall for India as one unit, and five homogeneous monsoon regions, based on ENSO and EQUINOO indices of months of March, April and May only, performed at end of month of May. In this case, All India Summer Monsoon Rainfall could be predicted with 0.70 as correlation coefficient with somewhat lesser Correlation Coefficient (C.C.) values for different

  10. Tropical Deforestation.

    Science.gov (United States)

    Raven, Peter H.

    1988-01-01

    Outlines the deforestation problem and some efforts for solving the problem. Considers the impact of population growth, poverty, and ignorance. Includes a discussion of the current rapid decline in tropical forests, the consequences of destruction, and an outlook for the future. (YP)

  11. Gender Based Violence among Infertile Women In Mara Region ...

    African Journals Online (AJOL)

    This paper examines women to women marriages (nyumba ntobhu) and its relation with gender-based violence (GBV) in Serengeti District of Mara Region. It also explores types of gender-based violence and consequences of women to women marriages among women, girls and children in the society. Both quantitative ...

  12. Region-Based Color Image Indexing and Retrieval

    DEFF Research Database (Denmark)

    Kompatsiaris, Ioannis; Triantafyllou, Evangelia; Strintzis, Michael G.

    2001-01-01

    In this paper a region-based color image indexing and retrieval algorithm is presented. As a basis for the indexing, a novel K-Means segmentation algorithm is used, modified so as to take into account the coherence of the regions. A new color distance is also defined for this algorithm. Based on ....... Experimental results demonstrate the performance of the algorithm. The development of an intelligent image content-based search engine for the World Wide Web is also presented, as a direct application of the presented algorithm....

  13. Tropic Testing of Vehicles

    Science.gov (United States)

    2014-08-27

    kilometer track running through tropical forest. The track is a combination of a bauxite /dirt base with grades on the road up to 20 percent and log...bridges crossing 11 creeks. The track site is located in a private concession used mainly for gold mining ; however, logging operations are active in the

  14. The Brazilian Developments on the Regional Atmospheric Modeling System (BRAMS 5.2): An Integrated Environmental Model Tuned for Tropical Areas

    Science.gov (United States)

    Freitas, Saulo R.; Panetta, Jairo; Longo, Karla M.; Rodrigues, Luiz F.; Moreira, Demerval S.; Rosario, Nilton E.; Silva Dias, Pedro L.; Silva Dias, Maria A. F.; Souza, Enio P.; Freitas, Edmilson D.; hide

    2017-01-01

    We present a new version of the Brazilian developments on the Regional Atmospheric Modeling System where different previous versions for weather, chemistry and carbon cycle were unified in a single integrated software system. The new version also has a new set of state-of-the-art physical parameterizations and greater computational parallel and memory usage efficiency. Together with the description of the main features are examples of the quality of the transport scheme for scalars, radiative fluxes on surface and model simulation of rainfall systems over South America in different spatial resolutions using a scale-aware convective parameterization. Besides, the simulation of the diurnal cycle of the convection and carbon dioxide concentration over the Amazon Basin, as well as carbon dioxide fluxes from biogenic processes over a large portion of South America are shown. Atmospheric chemistry examples present model performance in simulating near-surface carbon monoxide and ozone in Amazon Basin and Rio de Janeiro megacity. For tracer transport and dispersion, it is demonstrated the model capabilities to simulate the volcanic ash 3-d redistribution associated with the eruption of a Chilean volcano. Then, the gain of computational efficiency is described with some details. BRAMS has been applied for research and operational forecasting mainly in South America. Model results from the operational weather forecast of BRAMS on 5 km grid spacing in the Center for Weather Forecasting and Climate Studies, INPE/Brazil, since 2013 are used to quantify the model skill of near surface variables and rainfall. The scores show the reliability of BRAMS for the tropical and subtropical areas of South America. Requirements for keeping this modeling system competitive regarding on its functionalities and skills are discussed. At last, we highlight the relevant contribution of this work on the building up of a South American community of model developers.

  15. Securing tropical forest carbon

    DEFF Research Database (Denmark)

    Scharlemann, Jörn P. W.; Kapos, Valerie; Campbell, Alison

    2010-01-01

    Forest loss and degradation in the tropics contribute 6-17% of all greenhouse gas emissions. Protected areas cover 217.2 million ha (19.6%) of the world's humid tropical forests and contain c. 70.3 petagrams of carbon (Pg C) in biomass and soil to 1 m depth. Between 2000 and 2005, we estimate...... that 1.75 million ha of forest were lost from protected areas in humid tropical forests, causing the emission of 0.25-0.33 Pg C. Protected areas lost about half as much carbon as the same area of unprotected forest. We estimate that the reduction of these carbon emissions from ongoing deforestation...... in protected sites in humid tropical forests could be valued at USD 6,200-7,400 million depending on the land use after clearance. This is >1.5 times the estimated spending on protected area management in these regions. Improving management of protected areas to retain forest cover better may be an important...

  16. A framework of region-based dynamic image fusion

    Institute of Scientific and Technical Information of China (English)

    WANG Zhong-hua; QIN Zheng; LIU Yu

    2007-01-01

    A new framework of region-based dynamic image fusion is proposed. First, the technique of target detection is applied to dynamic images (image sequences) to segment images into different targets and background regions. Then different fusion rules are employed in different regions so that the target information is preserved as much as possible. In addition, steerable non-separable wavelet frame transform is used in the process of multi-resolution analysis, so the system achieves favorable characters of orientation and invariant shift. Compared with other image fusion methods, experimental results showed that the proposed method has better capabilities of target recognition and preserves clear background information.

  17. Classification of tree species based on longwave hyperspectral data from leaves, a case study for a tropical dry forest

    Science.gov (United States)

    Harrison, D.; Rivard, B.; Sánchez-Azofeifa, A.

    2018-04-01

    Remote sensing of the environment has utilized the visible, near and short-wave infrared (IR) regions of the electromagnetic (EM) spectrum to characterize vegetation health, vigor and distribution. However, relatively little research has focused on the use of the longwave infrared (LWIR, 8.0-12.5 μm) region for studies of vegetation. In this study LWIR leaf reflectance spectra were collected in the wet seasons (May through December) of 2013 and 2014 from twenty-six tree species located in a high species diversity environment, a tropical dry forest in Costa Rica. A continuous wavelet transformation (CWT) was applied to all spectra to minimize noise and broad amplitude variations attributable to non-compositional effects. Species discrimination was then explored with Random Forest classification and accuracy improved was observed with preprocessing of reflectance spectra with continuous wavelet transformation. Species were found to share common spectral features that formed the basis for five spectral types that were corroborated with linear discriminate analysis. The source of most of the observed spectral features is attributed to cell wall or cuticle compounds (cellulose, cutin, matrix glycan, silica and oleanolic acid). Spectral types could be advantageous for the analysis of airborne hyperspectral data because cavity effects will lower the spectral contrast thus increasing the reliance of classification efforts on dominant spectral features. Spectral types specifically derived from leaf level data are expected to support the labeling of spectral classes derived from imagery. The results of this study and that of Ribeiro Da Luz (2006), Ribeiro Da Luz and Crowley (2007, 2010), Ullah et al. (2012) and Rock et al. (2016) have now illustrated success in tree species discrimination across a range of ecosystems using leaf-level spectral observations. With advances in LWIR sensors and concurrent improvements in their signal to noise, applications to large-scale species

  18. Phylogenetic classification of the world's tropical forests

    NARCIS (Netherlands)

    Slik, J.W.F.; Franklin, Janet; Arroyo-Rodríguez, Víctor; Field, Richard; Aguilar, Salomon; Aguirre, Nikolay; Ahumada, Jorge; Aiba, Shin Ichiro; Alves, Luciana F.; Anitha, K.; Avella, Andres; Mora, Francisco; Aymard, Gerardo A.C.; Báez, Selene; Balvanera, Patricia; Bastian, Meredith L.; Bastin, Jean François; Bellingham, Peter J.; Berg, Van Den Eduardo; Conceição Bispo, Da Polyanna; Boeckx, Pascal; Boehning-Gaese, Katrin; Bongers, Frans; Boyle, Brad; Brambach, Fabian; Brearley, Francis Q.; Brown, Sandra; Chai, Shauna Lee; Chazdon, Robin L.; Chen, Shengbin; Chhang, Phourin; Chuyong, George; Ewango, Corneille; Coronado, Indiana M.; Cristóbal-Azkarate, Jurgi; Culmsee, Heike; Damas, Kipiro; Dattaraja, H.S.; Davidar, Priya; DeWalt, Saara J.; Din, Hazimah; Drake, Donald R.; Duque, Alvaro; Durigan, Giselda; Eichhorn, Karl; Eler, Eduardo Schmidt; Enoki, Tsutomu; Ensslin, Andreas; Fandohan, Adandé Belarmain; Farwig, Nina; Feeley, Kenneth J.; Fischer, Markus; Forshed, Olle; Garcia, Queila Souza; Garkoti, Satish Chandra; Gillespie, Thomas W.; Gillet, Jean Francois; Gonmadje, Christelle; Granzow-De La Cerda, Iñigo; Griffith, Daniel M.; Grogan, James; Hakeem, Khalid Rehman; Harris, David J.; Harrison, Rhett D.; Hector, Andy; Hemp, Andreas; Homeier, Jürgen; Hussain, M.S.; Ibarra-Manríquez, Guillermo; Hanum, I.F.; Imai, Nobuo; Jansen, Patrick A.; Joly, Carlos Alfredo; Joseph, Shijo; Kartawinata, Kuswata; Kearsley, Elizabeth; Kelly, Daniel L.; Kessler, Michael; Killeen, Timothy J.; Kooyman, Robert M.; Laumonier, Yves; Laurance, Susan G.; Laurance, William F.; Lawes, Michael J.; Letcher, Susan G.; Lindsell, Jeremy; Lovett, Jon; Lozada, Jose; Lu, Xinghui; Lykke, Anne Mette; Mahmud, Bin Khairil; Mahayani, Ni Putu Diana; Mansor, Asyraf; Marshall, Andrew R.; Martin, Emanuel H.; Matos, Darley Calderado Leal; Meave, Jorge A.; Melo, Felipe P.L.; Mendoza, Zhofre Huberto Aguirre; Metali, Faizah; Medjibe, Vincent P.; Metzger, Jean Paul; Metzker, Thiago; Mohandass, D.; Munguía-Rosas, Miguel A.; Muñoz, Rodrigo; Nurtjahy, Eddy; Oliveira, De Eddie Lenza; Onrizal,; Parolin, Pia; Parren, Marc; Parthasarathy, N.; Paudel, Ekananda; Perez, Rolando; Pérez-García, Eduardo A.; Pommer, Ulf; Poorter, Lourens; Qi, Lan; Piedade, Maria Teresa F.; Pinto, José Roberto Rodrigues; Poulsen, Axel Dalberg; Poulsen, John R.; Powers, Jennifer S.; Prasad, Rama Chandra; Puyravaud, Jean Philippe; Rangel, Orlando; Reitsma, Jan; Rocha, Diogo S.B.; Rolim, Samir; Rovero, Francesco; Rozak, Andes; Ruokolainen, Kalle; Rutishauser, Ervan; Rutten, Gemma; Mohd Said, Mohd Nizam; Saiter, Felipe Z.; Saner, Philippe; Santos, Braulio; Santos, Dos João Roberto; Sarker, Swapan Kumar; Schmitt, Christine B.; Schoengart, Jochen; Schulze, Mark; Sheil, Douglas; Sist, Plinio; Souza, Alexandre F.; Spironello, Wilson Roberto; Sposito, Tereza; Steinmetz, Robert; Stevart, Tariq; Suganuma, Marcio Seiji; Sukri, Rahayu; Sultana, Aisha; Sukumar, Raman; Sunderland, Terry; Supriyadi, S.; Suresh, H.S.; Suzuki, Eizi; Tabarelli, Marcelo; Tang, Jianwei; Tanner, Ed V.J.; Targhetta, Natalia; Theilade, Ida; Thomas, Duncan; Timberlake, Jonathan; Morisson Valeriano, De Márcio; Valkenburg, Van Johan; Do, Van Tran; Sam, Van Hoang; Vandermeer, John H.; Verbeeck, Hans; Vetaas, Ole Reidar; Adekunle, Victor; Vieira, Simone A.; Webb, Campbell O.; Webb, Edward L.; Whitfeld, Timothy; Wich, Serge; Williams, John; Wiser, Susan; Wittmann, Florian; Yang, Xiaobo; Yao, C.Y.A.; Yap, Sandra L.; Zahawi, Rakan A.; Zakaria, Rahmad; Zang, Runguo

    2018-01-01

    Knowledge about the biogeographic affinities of the world's tropical forests helps to better understand regional differences in forest structure, diversity, composition, and dynamics. Such understanding will enable anticipation of region-specific responses to global environmental change. Modern

  19. Trust regions in Kriging-based optimization with expected improvement

    Science.gov (United States)

    Regis, Rommel G.

    2016-06-01

    The Kriging-based Efficient Global Optimization (EGO) method works well on many expensive black-box optimization problems. However, it does not seem to perform well on problems with steep and narrow global minimum basins and on high-dimensional problems. This article develops a new Kriging-based optimization method called TRIKE (Trust Region Implementation in Kriging-based optimization with Expected improvement) that implements a trust-region-like approach where each iterate is obtained by maximizing an Expected Improvement (EI) function within some trust region. This trust region is adjusted depending on the ratio of the actual improvement to the EI. This article also develops the Kriging-based CYCLONE (CYClic Local search in OptimizatioN using Expected improvement) method that uses a cyclic pattern to determine the search regions where the EI is maximized. TRIKE and CYCLONE are compared with EGO on 28 test problems with up to 32 dimensions and on a 36-dimensional groundwater bioremediation application in appendices supplied as an online supplement available at http://dx.doi.org/10.1080/0305215X.2015.1082350. The results show that both algorithms yield substantial improvements over EGO and they are competitive with a radial basis function method.

  20. An aniso tropic brane world cosmological model with the bulk-based approach

    International Nuclear Information System (INIS)

    Uluyazi, G.

    2010-01-01

    To investigate brane world models there are two approaches; brane-based or bulk based. In the brane-based approach, the brane is chosen to be fixed on a coordinate system, where as in the bulk-based approach it is no longer static as it moves along the extra dimension. At first attempt, it is aimed to solve five dimensional field equations in the bulk, then limitation of Weyl Curvature describing geometrical anisotropy is analyzed.

  1. Modelling mean transit time of stream base flow during tropical cyclone rainstorm in a steep relief forested catchment

    Science.gov (United States)

    Lee, Jun-Yi; Huang, -Chuan, Jr.

    2017-04-01

    Mean transit time (MTT) is one of the of fundamental catchment descriptors to advance understanding on hydrological, ecological, and biogeochemical processes and improve water resources management. However, there were few documented the base flow partitioning (BFP) and mean transit time within a mountainous catchment in typhoon alley. We used a unique data set of 18O isotope and conductivity composition of rainfall (136 mm to 778 mm) and streamflow water samples collected for 14 tropical cyclone events (during 2011 to 2015) in a steep relief forested catchment (Pinglin, in northern Taiwan). A lumped hydrological model, HBV, considering dispersion model transit time distribution was used to estimate total flow, base flow, and MTT of stream base flow. Linear regression between MTT and hydrometric (precipitation intensity and antecedent precipitation index) variables were used to explore controls on MTT variation. Results revealed that both the simulation performance of total flow and base flow were satisfactory, and the Nash-Sutcliffe model efficiency coefficient of total flow and base flow was 0.848 and 0.732, respectively. The event magnitude increased with the decrease of estimated MTTs. Meanwhile, the estimated MTTs varied 4-21 days with the increase of BFP between 63-92%. The negative correlation between event magnitude and MTT and BFP showed the forcing controls the MTT and BFP. Besides, a negative relationship between MTT and the antecedent precipitation index was also found. In other words, wetter antecedent moisture content more rapidly active the fast flow paths. This approach is well suited for constraining process-based modeling in a range of high precipitation intensity and steep relief forested environments.

  2. Defining a region of optimization based on engine usage data

    Science.gov (United States)

    Jiang, Li; Lee, Donghoon; Yilmaz, Hakan; Stefanopoulou, Anna

    2015-08-04

    Methods and systems for engine control optimization are provided. One or more operating conditions of a vehicle engine are detected. A value for each of a plurality of engine control parameters is determined based on the detected one or more operating conditions of the vehicle engine. A range of the most commonly detected operating conditions of the vehicle engine is identified and a region of optimization is defined based on the range of the most commonly detected operating conditions of the vehicle engine. The engine control optimization routine is initiated when the one or more operating conditions of the vehicle engine are within the defined region of optimization.

  3. Polynomial Chaos–Based Bayesian Inference of K-Profile Parameterization in a General Circulation Model of the Tropical Pacific

    KAUST Repository

    Sraj, Ihab

    2016-08-26

    The authors present a polynomial chaos (PC)-based Bayesian inference method for quantifying the uncertainties of the K-profile parameterization (KPP) within the MIT general circulation model (MITgcm) of the tropical Pacific. The inference of the uncertain parameters is based on a Markov chain Monte Carlo (MCMC) scheme that utilizes a newly formulated test statistic taking into account the different components representing the structures of turbulent mixing on both daily and seasonal time scales in addition to the data quality, and filters for the effects of parameter perturbations over those as a result of changes in the wind. To avoid the prohibitive computational cost of integrating the MITgcm model at each MCMC iteration, a surrogate model for the test statistic using the PC method is built. Because of the noise in the model predictions, a basis-pursuit-denoising (BPDN) compressed sensing approach is employed to determine the PC coefficients of a representative surrogate model. The PC surrogate is then used to evaluate the test statistic in the MCMC step for sampling the posterior of the uncertain parameters. Results of the posteriors indicate good agreement with the default values for two parameters of the KPP model, namely the critical bulk and gradient Richardson numbers; while the posteriors of the remaining parameters were barely informative. © 2016 American Meteorological Society.

  4. Species-Level Differences in Hyperspectral Metrics among Tropical Rainforest Trees as Determined by a Tree-Based Classifier

    Directory of Open Access Journals (Sweden)

    Dar A. Roberts

    2012-06-01

    Full Text Available This study explores a method to classify seven tropical rainforest tree species from full-range (400–2,500 nm hyperspectral data acquired at tissue (leaf and bark, pixel and crown scales using laboratory and airborne sensors. Metrics that respond to vegetation chemistry and structure were derived using narrowband indices, derivative- and absorption-based techniques, and spectral mixture analysis. We then used the Random Forests tree-based classifier to discriminate species with minimally-correlated, importance-ranked metrics. At all scales, best overall accuracies were achieved with metrics derived from all four techniques and that targeted chemical and structural properties across the visible to shortwave infrared spectrum (400–2500 nm. For tissue spectra, overall accuracies were 86.8% for leaves, 74.2% for bark, and 84.9% for leaves plus bark. Variation in tissue metrics was best explained by an axis of red absorption related to photosynthetic leaves and an axis distinguishing bark water and other chemical absorption features. Overall accuracies for individual tree crowns were 71.5% for pixel spectra, 70.6% crown-mean spectra, and 87.4% for a pixel-majority technique. At pixel and crown scales, tree structure and phenology at the time of image acquisition were important factors that determined species spectral separability.

  5. Hydrological structure and biological productivity of the tropical Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Muraleedharan, U.D.; Muraleedharan, P.M.

    Hydrological structure analyses of regions in the tropical Atlantic Ocean have consistently revealed the existence of a typical tropical structure characterized by a nitrate-depleted mixed layer above the thermocline. The important biological...

  6. Region based Brain Computer Interface for a home control application.

    Science.gov (United States)

    Akman Aydin, Eda; Bay, Omer Faruk; Guler, Inan

    2015-08-01

    Environment control is one of the important challenges for disabled people who suffer from neuromuscular diseases. Brain Computer Interface (BCI) provides a communication channel between the human brain and the environment without requiring any muscular activation. The most important expectation for a home control application is high accuracy and reliable control. Region-based paradigm is a stimulus paradigm based on oddball principle and requires selection of a target at two levels. This paper presents an application of region based paradigm for a smart home control application for people with neuromuscular diseases. In this study, a region based stimulus interface containing 49 commands was designed. Five non-disabled subjects were attended to the experiments. Offline analysis results of the experiments yielded 95% accuracy for five flashes. This result showed that region based paradigm can be used to select commands of a smart home control application with high accuracy in the low number of repetitions successfully. Furthermore, a statistically significant difference was not observed between the level accuracies.

  7. Model-based automatic generation of grasping regions

    Science.gov (United States)

    Bloss, David A.

    1993-01-01

    The problem of automatically generating stable regions for a robotic end effector on a target object, given a model of the end effector and the object is discussed. In order to generate grasping regions, an initial valid grasp transformation from the end effector to the object is obtained based on form closure requirements, and appropriate rotational and translational symmetries are associated with that transformation in order to construct a valid, continuous grasping region. The main result of this algorithm is a list of specific, valid grasp transformations of the end effector to the target object, and the appropriate combinations of translational and rotational symmetries associated with each specific transformation in order to produce a continuous grasp region.

  8. Evolution of Microsatellite Loci of Tropical and Temperate Anguilla Eels

    Directory of Open Access Journals (Sweden)

    Mei-Chen Tseng

    2012-04-01

    Full Text Available Anguilla eels are divided into temperate and tropical eels, based on their major distributions. The present study collected two temperate eels, Anguilla japonica and Anguilla anguilla, and two tropical eels, Anguilla marmorata and Anguilla bicolor pacifica, to examine two questions: do temperate and tropical Anguilla eels have different genetic polymorphic patterns?; and do temperate Anguilla japonica and Anguilla anguilla have a closer relationship to each other than to tropical eels? In total, 274 sequences were cloned and sequenced from six conserved microsatellite loci to examine polymorphic patterns of these four catadromous eels. Different mutational events, including substitutions, and repeat-unit deletions and insertions, appeared in major regions, while different point mutations were observed in flanking regions. The results implied that parallel patterns of microsatellite sequences occurred within both tropical and temperate freshwater eels. Consensus flanking sequences of six homologous loci from each of the four species were constructed. Genetic distances ranged from 0.044 (Anguilla bicolor pacifica vs. Anguilla marmorata to 0.061 (Anguilla marmorata vs. Anguilla anguilla. The tree topology suggests the hypothesis of Anguilla japonica and Anguilla anguilla being a sister group must be rejected.

  9. Random Valued Impulse Noise Removal Using Region Based Detection Approach

    Directory of Open Access Journals (Sweden)

    S. Banerjee

    2017-12-01

    Full Text Available Removal of random valued noisy pixel is extremely challenging when the noise density is above 50%. The existing filters are generally not capable of eliminating such noise when density is above 70%. In this paper a region wise density based detection algorithm for random valued impulse noise has been proposed. On the basis of the intensity values, the pixels of a particular window are sorted and then stored into four regions. The higher density based region is considered for stepwise detection of noisy pixels. As a result of this detection scheme a maximum of 75% of noisy pixels can be detected. For this purpose this paper proposes a unique noise removal algorithm. It was experimentally proved that the proposed algorithm not only performs exceptionally when it comes to visual qualitative judgment of standard images but also this filter combination outsmarts the existing algorithm in terms of MSE, PSNR and SSIM comparison even up to 70% noise density level.

  10. A consumption-based, regional input-output analysis of greenhouse gas emissions and the carbon regional index

    DEFF Research Database (Denmark)

    Boyd, Britta; Mangalagiu, Diana; Straatman, Bas

    2018-01-01

    This paper presents a consumption-based method accounting for greenhouse gas emissions at regional level based on a multi-region input-output model. The method is based on regional consumption and includes imports and exports of emissions, factual emission developments, green investments as well...

  11. Knowledge base combinations and innovation performance in Swedish regions

    Czech Academy of Sciences Publication Activity Database

    Grillitsch, M.; Martin, R.; Srholec, Martin

    2017-01-01

    Roč. 93, č. 5 (2017), s. 458-479 ISSN 0013-0095 Institutional support: Progres-Q24 Keywords : knowledge base * knowledge combination * region Subject RIV: AH - Economics OBOR OECD: Applied Economics, Econometrics Impact factor: 5.344, year: 2016

  12. Knowledge base combinations and innovation performance in Swedish regions

    Czech Academy of Sciences Publication Activity Database

    Grillitsch, M.; Martin, R.; Srholec, Martin

    2017-01-01

    Roč. 93, č. 5 (2017), s. 458-479 ISSN 0013-0095 Institutional support: RVO:67985998 Keywords : knowledge base * knowledge combination * region Subject RIV: AH - Economics OBOR OECD: Applied Economics, Econometrics Impact factor: 5.344, year: 2016

  13. An engine for global plant diversity: Highest evolutionary turnover and emigration in the American tropics

    Directory of Open Access Journals (Sweden)

    Alexandre eAntonelli

    2015-04-01

    Full Text Available Understanding the processes that have generated the latitudinal biodiversity gradient and the continental differences in tropical biodiversity remains a major goal of evolutionary biology. Here we estimate the timing and direction of range shifts of extant flowering plants (angiosperms between tropical and non-tropical zones, and into and out of the major tropical regions of the world. We then calculate rates of speciation and extinction taking into account incomplete taxonomic sampling. We use a recently published fossil calibrated phylogeny and apply novel bioinformatic tools to code species into user-defined polygons. We reconstruct biogeographic history using stochastic character mapping to compute relative numbers of range shifts in proportion to the number of available lineages through time. Our results, based on the analysis of c. 22,600 species and c. 20 million geo-referenced occurrence records, show no significant differences between the speciation and extinction of tropical and non-tropical angiosperms. This suggests that at least in plants, the tropical biodiversity gradient primarily derives from other factors than differential rates of diversification. In contrast, the outstanding species richness found today in the American tropics (the Neotropics, as compared to tropical Africa and tropical Asia, is associated with significantly higher speciation and extinction rates. This suggests an exceedingly rapid evolutionary turnover, i.e. Neotropical species being formed and replaced by one another at unparalleled rates. In addition, tropical America stands out from other continents by having ‘pumped out’ more species than it received through most of the last 66 million years. These results imply that the Neotropics have acted as an engine for global plant diversity.

  14. Sensitivity of global and regional terrestrial carbon storage to the direct CO2 effect and climate change based on the CMIP5 model intercomparison.

    Science.gov (United States)

    Peng, Jing; Dan, Li; Huang, Mei

    2014-01-01

    Global and regional land carbon storage has been significantly affected by increasing atmospheric CO2 concentration and climate change. Based on fully coupled climate-carbon-cycle simulations from the Coupled Model Intercomparison Project Phase 5 (CMIP5), we investigate sensitivities of land carbon storage to rising atmospheric CO2 concentration and climate change over the world and 21 regions during the 130 years. Overall, the simulations suggest that consistently spatial positive effects of the increasing CO2 concentrations on land carbon storage are expressed with a multi-model averaged value of 1.04 PgC per ppm. The stronger positive values are mainly located in the broad areas of temperate and tropical forest, especially in Amazon basin and western Africa. However, large heterogeneity distributed for sensitivities of land carbon storage to climate change. Climate change causes decrease in land carbon storage in most tropics and the Southern Hemisphere. In these regions, decrease in soil moisture (MRSO) and enhanced drought somewhat contribute to such a decrease accompanied with rising temperature. Conversely, an increase in land carbon storage has been observed in high latitude and altitude regions (e.g., northern Asia and Tibet). The model simulations also suggest that global negative impacts of climate change on land carbon storage are predominantly attributed to decrease in land carbon storage in tropics. Although current warming can lead to an increase in land storage of high latitudes of Northern Hemisphere due to elevated vegetation growth, a risk of exacerbated future climate change may be induced due to release of carbon from tropics.

  15. Sensitivity of global and regional terrestrial carbon storage to the direct CO2 effect and climate change based on the CMIP5 model intercomparison.

    Directory of Open Access Journals (Sweden)

    Jing Peng

    Full Text Available Global and regional land carbon storage has been significantly affected by increasing atmospheric CO2 concentration and climate change. Based on fully coupled climate-carbon-cycle simulations from the Coupled Model Intercomparison Project Phase 5 (CMIP5, we investigate sensitivities of land carbon storage to rising atmospheric CO2 concentration and climate change over the world and 21 regions during the 130 years. Overall, the simulations suggest that consistently spatial positive effects of the increasing CO2 concentrations on land carbon storage are expressed with a multi-model averaged value of 1.04 PgC per ppm. The stronger positive values are mainly located in the broad areas of temperate and tropical forest, especially in Amazon basin and western Africa. However, large heterogeneity distributed for sensitivities of land carbon storage to climate change. Climate change causes decrease in land carbon storage in most tropics and the Southern Hemisphere. In these regions, decrease in soil moisture (MRSO and enhanced drought somewhat contribute to such a decrease accompanied with rising temperature. Conversely, an increase in land carbon storage has been observed in high latitude and altitude regions (e.g., northern Asia and Tibet. The model simulations also suggest that global negative impacts of climate change on land carbon storage are predominantly attributed to decrease in land carbon storage in tropics. Although current warming can lead to an increase in land storage of high latitudes of Northern Hemisphere due to elevated vegetation growth, a risk of exacerbated future climate change may be induced due to release of carbon from tropics.

  16. Reforms from the Ground Up: A Review of Community-Based Forest Management in Tropical Developing Countries

    Science.gov (United States)

    Tole, Lise

    2010-06-01

    After an initial burst of enthusiasm in the 1990s, community-based forest management (CBFM) is increasingly being viewed with a critical eye. Evidence suggests that many programs have failed to promote their stated objectives of sustainability, efficiency, equity, democratic participation and poverty reduction. A large volume of academic literature now exists on CBFM, examining both the success and failure of such initiatives in a wide variety of countries. Through analysis of key themes, concepts and issues in CBFM, this article provides a review of CBFM initiatives in tropical developing countries for policymakers, practitioners and planners wishing to gain an understanding of this wide-ranging, interdisciplinary academic literature. The article identifies key institutions and incentives that appear to significantly affect the success or failure of CBFM initiatives. In particular, it reports that consideration of institutional and socioeconomic factors along with personal characteristics of key stakeholders such as beliefs, attitudes, financial resources and skills are important determinants of CBFM outcomes. However, local incentive structures also appear to be important. There is increasing recognition in the literature of the need to consider the conditions under which local politicians entrusted with carrying out CBFM initiatives will deem it worthwhile to invest their scarce time and resources on environmental governance.

  17. Temperature variability over the tropical middle atmosphere

    Directory of Open Access Journals (Sweden)

    K. Mohanakumar

    1994-04-01

    Full Text Available A study on the variability of temperature in the tropical middle atmosphere over Thumba (8 32' N, 76 52' E, located at the southern part of India, has been carried out based on rocket observations for a period of 20 years, extending from 1970 to 1990. The rocketsonde-derived mean temperatures over Thumba are corrected prior to 1978 and then compared with the middle atmospheric reference model developed from satellite observations and Solar Mesosphere Explorer (SME satellite data. Temperature variability at every 1 km interval in the 25-75 km region was analysed. The tropical stratosphere is found to be highly stable, whereas considerable variability is noted in the middle mesosphere. The effect of seasonal cycle is least in the lower stratosphere. Annual and semi-annual oscillations in temperature are the primary oscillations in the tropical middle atmosphere. Annual temperature oscillations are dominant in the mesosphere and semi-annual oscillations are strong in the stratosphere. The stratopause region is noted to be the part of the middle atmosphere least sensitive to the changes in solar activity and long-term variability.

  18. A Region-Based Strategy for Collaborative Roadmap Construction

    KAUST Repository

    Denny, Jory; Sandströ m, Read; Julian, Nicole; Amato, Nancy M.

    2015-01-01

    © Springer International Publishing Switzerland 2015. Motion planning has seen much attention over the past two decades. A great deal of progress has been made in sampling-based planning, whereby a planner builds an approximate representation of the planning space. While these planners have demonstrated success inmany scenarios, there are still difficult problems where they lack robustness or efficiency, e.g., certain types of narrow spaces. Conversely, human intuition can often determine an approximate solution to these problems quite effectively, but humans lack the speed and precision necessary to perform the corresponding low-level tasks (such as collision checking) in a timely manner. In this work, we introduce a novel strategy called Region Steering in which the user and a PRM planner work cooperatively to map the space while maintaining the probabilistic completeness property of the PRMplanner. Region Steering utilizes two-way communication to integrate the strengths of both the user and the planner, thereby overcoming the weaknesses inherent to relying on either one alone. In one communication direction, a user can input regions, or bounding volumes in the workspace, to bias sampling towards or away from these areas. In the other direction, the planner displays its progress to the user and colors the regions based on their perceived usefulness.We demonstrate that Region Steering provides roadmap customizability, reduced mapping time, and smaller roadmap sizes compared with fully automated PRMs, e.g., Gaussian PRM.

  19. Morphological study of maxillary canine region based on CT

    International Nuclear Information System (INIS)

    Yamada, Maiko; Takamori, Hitoshi; Ide, Yoshiaki; Yosue, Takashi

    2010-01-01

    The maxilla is generally known as a site where anatomical limitations make it difficult to obtain sufficient bone volume. A large amount of bone exists in the canine region between the anterior margin of the maxillary sinus and the piriform aperture margin. Although this region is crucial for implant treatments, there have not been any reports on morphological studies of the region. In this study, we investigated the morphology of the canine region based on CT, and also the morphology and position of the maxillary sinus located posterior to the canine region. The results were as follows: In the area above the anterior nasal spine, the higher the level, the smaller the mesio-distal length and the bucco-lingual width tended to become. In the area above the anterior nasal spine, the mesio-distal length and the bucco-lingual width tended to be smaller in female patients than in male patients. In the area above the anterior nasal spine, no significant differences in mesio-distal length and bucco-lingual width were observed between dentulous and edentulous jaws. The morphology of the maxillary sinus was mainly of an inverse-trapezoidal, circular, or triangular form. The position of the anterior wall of the maxillary sinus was most frequently found at the site corresponding to the second premolar. Through this study, we have reconfirmed that the canine region is vital for implant treatments in the maxilla. (author)

  20. Identification of Tropical-Extratropical Interactions and Extreme Precipitation Events in the Middle East based on Potential Vorticity and Moisture Transport

    KAUST Repository

    de Vries, A. J.

    2017-12-26

    Extreme precipitation events in the otherwise arid Middle East can cause flooding with dramatic socioeconomic impacts. Most of these events are associated with tropical-extratropical interactions, whereby a stratospheric potential vorticity (PV) intrusion reaches deep into the subtropics and forces an incursion of high poleward vertically integrated water vapor transport (IVT) into the Middle East. This study presents an object-based identification method for extreme precipitation events based on the combination of these two larger-scale meteorological features. The general motivation for this approach is that precipitation is often poorly simulated in relatively coarse weather and climate models, whereas the synoptic-scale circulation is much better represented. The algorithm is applied to ERA-Interim reanalysis data (1979-2015) and detects 90% (83%) of the 99th (97.5th) percentile of extreme precipitation days in the region of interest. Our results show that stratospheric PV intrusions and IVT structures are intimately connected to extreme precipitation intensity and seasonality. The farther south a stratospheric PV intrusion reaches, the larger the IVT magnitude, and the longer the duration of their combined occurrence, the more extreme the precipitation. Our algorithm detects a large fraction of the climatological rainfall amounts (40-70%), heavy precipitation days (50-80%), and the top 10 extreme precipitation days (60-90%) at many sites in southern Israel and the northern and western parts of Saudi Arabia. This identification method provides a new tool for future work to disentangle teleconnections, assess medium-range predictability and improve understanding of climatic changes of extreme precipitation in the Middle East and elsewhere.

  1. Identification of Tropical-Extratropical Interactions and Extreme Precipitation Events in the Middle East Based On Potential Vorticity and Moisture Transport

    Science.gov (United States)

    de Vries, A. J.; Ouwersloot, H. G.; Feldstein, S. B.; Riemer, M.; El Kenawy, A. M.; McCabe, M. F.; Lelieveld, J.

    2018-01-01

    Extreme precipitation events in the otherwise arid Middle East can cause flooding with dramatic socioeconomic impacts. Most of these events are associated with tropical-extratropical interactions, whereby a stratospheric potential vorticity (PV) intrusion reaches deep into the subtropics and forces an incursion of high poleward vertically integrated water vapor transport (IVT) into the Middle East. This study presents an object-based identification method for extreme precipitation events based on the combination of these two larger-scale meteorological features. The general motivation for this approach is that precipitation is often poorly simulated in relatively coarse weather and climate models, whereas the synoptic-scale circulation is much better represented. The algorithm is applied to ERA-Interim reanalysis data (1979-2015) and detects 90% (83%) of the 99th (97.5th) percentile of extreme precipitation days in the region of interest. Our results show that stratospheric PV intrusions and IVT structures are intimately connected to extreme precipitation intensity and seasonality. The farther south a stratospheric PV intrusion reaches, the larger the IVT magnitude, and the longer the duration of their combined occurrence, the more extreme the precipitation. Our algorithm detects a large fraction of the climatological rainfall amounts (40-70%), heavy precipitation days (50-80%), and the top 10 extreme precipitation days (60-90%) at many sites in southern Israel and the northern and western parts of Saudi Arabia. This identification method provides a new tool for future work to disentangle teleconnections, assess medium-range predictability, and improve understanding of climatic changes of extreme precipitation in the Middle East and elsewhere.

  2. Functional diversity of fish in tropical estuaries: A traits-based approach of communities in Pernambuco, Brazil

    Science.gov (United States)

    Silva-Júnior, C. A. B.; Mérigot, B.; Lucena-Frédou, F.; Ferreira, B. P.; Coxey, M. S.; Rezende, S. M.; Frédou, T.

    2017-11-01

    Environmental changes and human activities may have strong impacts on biodiversity and ecosystem functioning. While biodiversity is traditionally based on species richness and composition, there is a growing concern to take into account functional diversity to assess and manage species communities. In spite of their economic importance, functional diversity quantified by a traits-based approach is still poorly documented in tropical estuaries. In this study, the functional diversity of fishes was investigated within four estuaries in Pernambuco state, northeast of Brazil. These areas are subject to different levels of human impact (e.g. mangrove deforestation, shrimp farming, fishing etc.) and environmental conditions. Fishes were collected during 34 scientific surveys. A total of 122 species were identified and 12 functional traits were quantified describing two main functions: food acquisition and locomotion. Fish abundance and functional dissimilarities data were combined into a multivariate analysis, the Double Principal Coordinate Analysis, to identify the functional typology of fish assemblages according to the estuary. Results showed that Itapissuma, the largest estuary with a wider mangrove forest area, differs from the other three estuaries, showing higher mean values per samples of species richness S and quadratic entropy Q. Similarly, it presented a different functional typology (the first two axes of the DPCoA account for 68.7% of total inertia, while those of a traditional PCA based solely on species abundances provided only 17.4%). Conversely, Suape, Sirinhaém, and to a lower extent Rio Formoso, showed more similarity in their diversity. This result was attributed to their predominantly marine influenced hydrological features, and similar levels of species abundances and in morphological traits. Overall, this study, combining diversity indices and a recent multivariate analysis to access species contribution to functional typology, allows to deepen

  3. Regional markets with agricultural workforce based on Labour offices' data

    Directory of Open Access Journals (Sweden)

    František Nohel

    2011-01-01

    Full Text Available The changes in Czech agriculture over the past twenty years have had their impact on the agricultural labour market, too. The regional differentiation of the chances of applicants on the labour market as well as the agricultural enterprises’ chances of hiring employees fitting their requirements, are, among others, influenced by the specific conditions of agricultural production. The aim of this paper pertains to two basic problem areas: first, the differentiation of respective regions based on the number of agricultural applicants and job vacancies, and second, the identification of disequilibrium on the agricultural labour market. The latter is based on a theoretical framework defined by approaches in economy dealing with labour market equilibrium. Due to the unavailability of economic data (including wages, economic performance, etc. on the regional level, authors develop their own methodological approach, based on the number of applicants per job vacancy. A database of applicants and vacancies available from the Labour Offices is used as a source for the analysis and interpretation of data, enabling us to study the agricultural labour market not only sector-wise but also region-wise.

  4. How can hydrological modeling help to understand process dynamics in sparsely gauged tropical regions - case study Mata Âtlantica, Brazil

    Science.gov (United States)

    Künne, Annika; Penedo, Santiago; Schuler, Azeneth; Bardy Prado, Rachel; Kralisch, Sven; Flügel, Wolfgang-Albert

    2015-04-01

    To ensure long-term water security for domestic, agricultural and industrial use in the emerging country of Brazil with fast-growing markets and technologies, understanding of catchment hydrology is essential. Yet, hydrological analysis, high resolution temporal and spatial monitoring and reliable meteo-hydrological data are insufficient to fully understand hydrological processes in the region and to predict future trends. Physically based hydrological modeling can help to expose uncertainties of measured data, predict future trends and contribute to physical understanding about the watershed. The Brazilian Atlantic rainforest (Mata Atlântica) is one of the world's biodiversity hotspots. After the Portuguese colonization, its original expansion of 1.5 million km² was reduced to only 7% of the former area. Due to forest fragmentation, overexploitation and soil degradation, pressure on water resources in the region has significantly increased. Climatically, the region possesses distinctive wet and dry periods. While extreme precipitation events in the rainy season cause floods and landslides, dry periods can lead to water shortages, especially in the agricultural and domestic supply sectors. To ensure both, the protection of the remnants of Atlantic rainforest biome as well as water supply, a hydrological understanding of this sparsely gauged region is essential. We will present hydrological models of two meso- to large-scale catchments (Rio Macacu and Rio Dois Rios) within the Mata Âtlantica in the state of Rio de Janeiro. The results show how physically based models can contribute to hydrological system understanding within the region and answer what-if scenarios, supporting regional planners and decision makers in integrated water resources management.

  5. Bioavailability and export of dissolved organic matter from a tropical river during base- and stormflow conditions

    Science.gov (United States)

    Tracy N. Wiegner; Randee L. Tubal; Richard A. MacKenzie

    2009-01-01

    Concentrations, bioavailability, and export of dissolved organic matter (DOM), particulate organic matter (POM), and nutrients from the Wailuku River, Hawai'i, U.S.A., were examined under base- and stormflow conditions. During storms, DOM and POM concentrations increased approximately by factors of 2 and 11, respectively, whereas NO3...

  6. Non-Destructive, Laser-Based Individual Tree Aboveground Biomass Estimation in a Tropical Rainforest

    Directory of Open Access Journals (Sweden)

    Muhammad Zulkarnain Abd Rahman

    2017-03-01

    Full Text Available Recent methods for detailed and accurate biomass and carbon stock estimation of forests have been driven by advances in remote sensing technology. The conventional approach to biomass estimation heavily relies on the tree species and site-specific allometric equations, which are based on destructive methods. This paper introduces a non-destructive, laser-based approach (terrestrial laser scanner for individual tree aboveground biomass estimation in the Royal Belum forest reserve, Perak, Malaysia. The study area is in the state park, and it is believed to be one of the oldest rainforests in the world. The point clouds generated for 35 forest plots, using the terrestrial laser scanner, were geo-rectified and cleaned to produce separate point clouds for individual trees. The volumes of tree trunks were estimated based on a cylinder model fitted to the point clouds. The biomasses of tree trunks were calculated by multiplying the volume and the species wood density. The biomasses of branches and leaves were also estimated based on the estimated volume and density values. Branch and leaf volumes were estimated based on the fitted point clouds using an alpha-shape approach. The estimated individual biomass and the total above ground biomass were compared with the aboveground biomass (AGB value estimated using existing allometric equations and individual tree census data collected in the field. The results show that the combination of a simple single-tree stem reconstruction and wood density can be used to estimate stem biomass comparable to the results usually obtained through existing allometric equations. However, there are several issues associated with the data and method used for branch and leaf biomass estimations, which need further improvement.

  7. Phylogenetic classification of the world's tropical forests.

    Science.gov (United States)

    Slik, J W Ferry; Franklin, Janet; Arroyo-Rodríguez, Víctor; Field, Richard; Aguilar, Salomon; Aguirre, Nikolay; Ahumada, Jorge; Aiba, Shin-Ichiro; Alves, Luciana F; K, Anitha; Avella, Andres; Mora, Francisco; Aymard C, Gerardo A; Báez, Selene; Balvanera, Patricia; Bastian, Meredith L; Bastin, Jean-François; Bellingham, Peter J; van den Berg, Eduardo; da Conceição Bispo, Polyanna; Boeckx, Pascal; Boehning-Gaese, Katrin; Bongers, Frans; Boyle, Brad; Brambach, Fabian; Brearley, Francis Q; Brown, Sandra; Chai, Shauna-Lee; Chazdon, Robin L; Chen, Shengbin; Chhang, Phourin; Chuyong, George; Ewango, Corneille; Coronado, Indiana M; Cristóbal-Azkarate, Jurgi; Culmsee, Heike; Damas, Kipiro; Dattaraja, H S; Davidar, Priya; DeWalt, Saara J; Din, Hazimah; Drake, Donald R; Duque, Alvaro; Durigan, Giselda; Eichhorn, Karl; Eler, Eduardo Schmidt; Enoki, Tsutomu; Ensslin, Andreas; Fandohan, Adandé Belarmain; Farwig, Nina; Feeley, Kenneth J; Fischer, Markus; Forshed, Olle; Garcia, Queila Souza; Garkoti, Satish Chandra; Gillespie, Thomas W; Gillet, Jean-Francois; Gonmadje, Christelle; Granzow-de la Cerda, Iñigo; Griffith, Daniel M; Grogan, James; Hakeem, Khalid Rehman; Harris, David J; Harrison, Rhett D; Hector, Andy; Hemp, Andreas; Homeier, Jürgen; Hussain, M Shah; Ibarra-Manríquez, Guillermo; Hanum, I Faridah; Imai, Nobuo; Jansen, Patrick A; Joly, Carlos Alfredo; Joseph, Shijo; Kartawinata, Kuswata; Kearsley, Elizabeth; Kelly, Daniel L; Kessler, Michael; Killeen, Timothy J; Kooyman, Robert M; Laumonier, Yves; Laurance, Susan G; Laurance, William F; Lawes, Michael J; Letcher, Susan G; Lindsell, Jeremy; Lovett, Jon; Lozada, Jose; Lu, Xinghui; Lykke, Anne Mette; Mahmud, Khairil Bin; Mahayani, Ni Putu Diana; Mansor, Asyraf; Marshall, Andrew R; Martin, Emanuel H; Calderado Leal Matos, Darley; Meave, Jorge A; Melo, Felipe P L; Mendoza, Zhofre Huberto Aguirre; Metali, Faizah; Medjibe, Vincent P; Metzger, Jean Paul; Metzker, Thiago; Mohandass, D; Munguía-Rosas, Miguel A; Muñoz, Rodrigo; Nurtjahy, Eddy; de Oliveira, Eddie Lenza; Onrizal; Parolin, Pia; Parren, Marc; Parthasarathy, N; Paudel, Ekananda; Perez, Rolando; Pérez-García, Eduardo A; Pommer, Ulf; Poorter, Lourens; Qie, Lan; Piedade, Maria Teresa F; Pinto, José Roberto Rodrigues; Poulsen, Axel Dalberg; Poulsen, John R; Powers, Jennifer S; Prasad, Rama Chandra; Puyravaud, Jean-Philippe; Rangel, Orlando; Reitsma, Jan; Rocha, Diogo S B; Rolim, Samir; Rovero, Francesco; Rozak, Andes; Ruokolainen, Kalle; Rutishauser, Ervan; Rutten, Gemma; Mohd Said, Mohd Nizam; Saiter, Felipe Z; Saner, Philippe; Santos, Braulio; Dos Santos, João Roberto; Sarker, Swapan Kumar; Schmitt, Christine B; Schoengart, Jochen; Schulze, Mark; Sheil, Douglas; Sist, Plinio; Souza, Alexandre F; Spironello, Wilson Roberto; Sposito, Tereza; Steinmetz, Robert; Stevart, Tariq; Suganuma, Marcio Seiji; Sukri, Rahayu; Sultana, Aisha; Sukumar, Raman; Sunderland, Terry; Supriyadi; Suresh, H S; Suzuki, Eizi; Tabarelli, Marcelo; Tang, Jianwei; Tanner, Ed V J; Targhetta, Natalia; Theilade, Ida; Thomas, Duncan; Timberlake, Jonathan; de Morisson Valeriano, Márcio; van Valkenburg, Johan; Van Do, Tran; Van Sam, Hoang; Vandermeer, John H; Verbeeck, Hans; Vetaas, Ole Reidar; Adekunle, Victor; Vieira, Simone A; Webb, Campbell O; Webb, Edward L; Whitfeld, Timothy; Wich, Serge; Williams, John; Wiser, Susan; Wittmann, Florian; Yang, Xiaobo; Adou Yao, C Yves; Yap, Sandra L; Zahawi, Rakan A; Zakaria, Rahmad; Zang, Runguo

    2018-02-20

    Knowledge about the biogeographic affinities of the world's tropical forests helps to better understand regional differences in forest structure, diversity, composition, and dynamics. Such understanding will enable anticipation of region-specific responses to global environmental change. Modern phylogenies, in combination with broad coverage of species inventory data, now allow for global biogeographic analyses that take species evolutionary distance into account. Here we present a classification of the world's tropical forests based on their phylogenetic similarity. We identify five principal floristic regions and their floristic relationships: ( i ) Indo-Pacific, ( ii ) Subtropical, ( iii ) African, ( iv ) American, and ( v ) Dry forests. Our results do not support the traditional neo- versus paleotropical forest division but instead separate the combined American and African forests from their Indo-Pacific counterparts. We also find indications for the existence of a global dry forest region, with representatives in America, Africa, Madagascar, and India. Additionally, a northern-hemisphere Subtropical forest region was identified with representatives in Asia and America, providing support for a link between Asian and American northern-hemisphere forests. Copyright © 2018 the Author(s). Published by PNAS.

  8. PROSPECTS OF THE REGIONAL INTEGRATION POLICY BASED ON CLUSTER FORMATION

    Directory of Open Access Journals (Sweden)

    Elena Tsepilova

    2018-01-01

    Full Text Available The purpose of this article is to develop the theoretical foundations of regional integration policy and to determine its prospects on the basis of cluster formation. The authors use such research methods as systematization, comparative and complex analysis, synthesis, statistical method. Within the framework of the research, the concept of regional integration policy is specified, and its integration core – cluster – is allocated. The authors work out an algorithm of regional clustering, which will ensure the growth of economy and tax income. Measures have been proposed to optimize the organizational mechanism of interaction between the participants of the territorial cluster and the authorities that allow to ensure the effective functioning of clusters, including taxation clusters. Based on the results of studying the existing methods for assessing the effectiveness of cluster policy, the authors propose their own approach to evaluating the consequences of implementing the regional integration policy, according to which the list of quantitative and qualitative indicators is defined. The present article systematizes the experience and results of the cluster policy of certain European countries, that made it possible to determine the prospects and synergetic effect from the development of clusters as an integration foundation of regional policy in the Russian Federation. The authors carry out the analysis of activity of cluster formations using the example of the Rostov region – a leader in the formation of conditions for the cluster policy development in the Southern Federal District. 11 clusters and cluster initiatives are developing in this region. As a result, the authors propose measures for support of the already existing clusters and creation of the new ones.

  9. Tropical Agroecosystems: These habitats are misunderstood by the temperate zones, mismanaged by the tropics.

    Science.gov (United States)

    Janzen, D H

    1973-12-21

    require a great deal of pantropical information exchange. This information exchange will cost a great deal of resource, not only in travel funds and support of on-site study, but in insurance policies for the countries that are willing to take the risk of trying to change from an exploitative agroecosystem to an SYTA. For such an experiment to be sociologically successful, it will require a complete change in tropical educational systems, from emphasizing descriptions of events as they now stand, to emphasizing analysis of why things happen the way they do. This will also be very expensive, not only in retreading the technology and mind-sets of current teaching programs, but in gathering the facts on why the tropics have met their current fate. There is a surfeit of biological and agricultural reports dealing with ecological experiments and generalities which suggest that such and such will be the outcome if such and such form of resource harvest is attempted. It is clear that human desiderata regarding a particular site are often radically different from the needs of the "average" wild animals and plants that formed the basis for such experiments and generalities. A finely tuned SYTA will come close to providing a unique solution for each region. The generalities that will rule it are highly stochastic. The more tropical the region, the more evenly weighted the suboutcomes will be, and thus the more likely each region will be to have a unique overall outcome. For example, it is easy to imagine four different parts of the tropics, each with the same kind of soil and the same climate, with four different, successful SYTA's, one based on paddy rice, one on shelterwood forestry, one on tourism, and one on shifting maize culture. A regional experiment station working holistically toward an SYTA is potentially one of the best solutions available. As currently structured, however, almost all tropical experiment stations are inadequate for such a mission. Most commonly they are

  10. A joint individual-based model coupling growth and mortality reveals that tree vigor is a key component of tropical forest dynamics.

    Science.gov (United States)

    Aubry-Kientz, Mélaine; Rossi, Vivien; Boreux, Jean-Jacques; Hérault, Bruno

    2015-06-01

    Tree vigor is often used as a covariate when tree mortality is predicted from tree growth in tropical forest dynamic models, but it is rarely explicitly accounted for in a coherent modeling framework. We quantify tree vigor at the individual tree level, based on the difference between expected and observed growth. The available methods to join nonlinear tree growth and mortality processes are not commonly used by forest ecologists so that we develop an inference methodology based on an MCMC approach, allowing us to sample the parameters of the growth and mortality model according to their posterior distribution using the joint model likelihood. We apply our framework to a set of data on the 20-year dynamics of a forest in Paracou, French Guiana, taking advantage of functional trait-based growth and mortality models already developed independently. Our results showed that growth and mortality are intimately linked and that the vigor estimator is an essential predictor of mortality, highlighting that trees growing more than expected have a far lower probability of dying. Our joint model methodology is sufficiently generic to be used to join two longitudinal and punctual linked processes and thus may be applied to a wide range of growth and mortality models. In the context of global changes, such joint models are urgently needed in tropical forests to analyze, and then predict, the effects of the ongoing changes on the tree dynamics in hyperdiverse tropical forests.

  11. Region-Based Building Rooftop Extraction and Change Detection

    Science.gov (United States)

    Tian, J.; Metzlaff, L.; d'Angelo, P.; Reinartz, P.

    2017-09-01

    Automatic extraction of building changes is important for many applications like disaster monitoring and city planning. Although a lot of research work is available based on 2D as well as 3D data, an improvement in accuracy and efficiency is still needed. The introducing of digital surface models (DSMs) to building change detection has strongly improved the resulting accuracy. In this paper, a post-classification approach is proposed for building change detection using satellite stereo imagery. Firstly, DSMs are generated from satellite stereo imagery and further refined by using a segmentation result obtained from the Sobel gradients of the panchromatic image. Besides the refined DSMs, the panchromatic image and the pansharpened multispectral image are used as input features for mean-shift segmentation. The DSM is used to calculate the nDSM, out of which the initial building candidate regions are extracted. The candidate mask is further refined by morphological filtering and by excluding shadow regions. Following this, all segments that overlap with a building candidate region are determined. A building oriented segments merging procedure is introduced to generate a final building rooftop mask. As the last step, object based change detection is performed by directly comparing the building rooftops extracted from the pre- and after-event imagery and by fusing the change indicators with the roof-top region map. A quantitative and qualitative assessment of the proposed approach is provided by using WorldView-2 satellite data from Istanbul, Turkey.

  12. REGION-BASED BUILDING ROOFTOP EXTRACTION AND CHANGE DETECTION

    Directory of Open Access Journals (Sweden)

    J. Tian

    2017-09-01

    Full Text Available Automatic extraction of building changes is important for many applications like disaster monitoring and city planning. Although a lot of research work is available based on 2D as well as 3D data, an improvement in accuracy and efficiency is still needed. The introducing of digital surface models (DSMs to building change detection has strongly improved the resulting accuracy. In this paper, a post-classification approach is proposed for building change detection using satellite stereo imagery. Firstly, DSMs are generated from satellite stereo imagery and further refined by using a segmentation result obtained from the Sobel gradients of the panchromatic image. Besides the refined DSMs, the panchromatic image and the pansharpened multispectral image are used as input features for mean-shift segmentation. The DSM is used to calculate the nDSM, out of which the initial building candidate regions are extracted. The candidate mask is further refined by morphological filtering and by excluding shadow regions. Following this, all segments that overlap with a building candidate region are determined. A building oriented segments merging procedure is introduced to generate a final building rooftop mask. As the last step, object based change detection is performed by directly comparing the building rooftops extracted from the pre- and after-event imagery and by fusing the change indicators with the roof-top region map. A quantitative and qualitative assessment of the proposed approach is provided by using WorldView-2 satellite data from Istanbul, Turkey.

  13. The PPP Precision Analysis Based on BDS Regional Navigation System

    Directory of Open Access Journals (Sweden)

    ZHU Yongxing

    2015-04-01

    Full Text Available BeiDou navigation satellite system(BDS has opened service in most of the Asia-Pacific region, it offers the possibility to break the technological monopoly of GPS in the field of high-precision applications, so its performance of precise point positioning (PPP has been a great concern. Firstly, the constellation of BeiDou regional navigation system and BDS/GPS tracking network is introduced. Secondly, the precise ephemeris and clock offset accuracy of BeiDou satellite based on domestic tracking network is analyzed. Finally, the static and kinematic PPP accuracy is studied, and compared with the GPS. The actual measured numerical example shows that the static and kinematic PPP based on BDS can achieve centimeter-level and decimeter-level respectively, reaching the current level of GPS precise point positioning.

  14. Carbon budget of tropical forests in Southeast Asia and the effects of deforestation: an approach using a process-based model and field measurements

    Directory of Open Access Journals (Sweden)

    M. Adachi

    2011-09-01

    Full Text Available More reliable estimates of the carbon (C stock within forest ecosystems and C emission induced by deforestation are urgently needed to mitigate the effects of emissions on climate change. A process-based terrestrial biogeochemical model (VISIT was applied to tropical primary forests of two types (a seasonal dry forest in Thailand and a rainforest in Malaysia and one agro-forest (an oil palm plantation in Malaysia to estimate the C budget of tropical ecosystems in Southeast Asia, including the impacts of land-use conversion. The observed aboveground biomass in the seasonal dry tropical forest in Thailand (226.3 t C ha−1 and the rainforest in Malaysia (201.5 t C ha−1 indicate that tropical forests of Southeast Asia are among the most C-abundant ecosystems in the world. The model simulation results in rainforests were consistent with field data, except for the NEP, however, the VISIT model tended to underestimate C budget and stock in the seasonal dry tropical forest. The gross primary production (GPP based on field observations ranged from 32.0 to 39.6 t C ha−1 yr−1 in the two primary forests, whereas the model slightly underestimated GPP (26.5–34.5 t C ha−1 yr−1. The VISIT model appropriately captured the impacts of disturbances such as deforestation and land-use conversions on the C budget. Results of sensitivity analysis showed that the proportion of remaining residual debris was a key parameter determining the soil C budget after the deforestation event. According to the model simulation, the total C stock (total biomass and soil C of the oil palm plantation was about 35% of the rainforest's C stock at 30 yr following initiation of the plantation. However, there were few field data of C budget and stock, especially in oil palm plantation. The C budget of each ecosystem must be evaluated over the long term using both the model simulations and observations to

  15. Feasibility of community-based health insurance in rural tropical Ecuador Factibilidad de un seguro de enfermedad comunitario en una zona rural tropical de Ecuador

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    Martin Eckhardt

    2011-03-01

    Full Text Available OBJECTIVE: The main objective of this study was to assess people's willingness to join a community-based health insurance (CHI model in El Páramo, a rural area in Ecuador, and to determine factors influencing this willingness. A second objective was to identify people's understanding and attitudes toward the presented CHI model. METHODS: A cross-sectional survey was carried out using a structured questionnaire. Of an estimated 829 households, 210 were randomly selected by two-stage cluster sampling. Attitudes toward the scheme were assessed. Information on factors possibly influencing willingness to join was collected and related to the willingness to join. To gain an insight into a respondent's possible ability to pay, health care expenditure on the last illness episode was assessed. Feasibility was defined as at least 50% of household heads willing to join the scheme. RESULTS: Willingness to join the CHI model for US$30 per year was 69.3%. With affiliation, 92.2% of interviewees stated that they would visit the local health facility more often. Willingness to join was found to be negatively associated with education. Other variables showed no significant association with willingness to join. The study showed a positive attitude toward the CHI scheme. Substantial health care expenditures on the last illness episode were documented. CONCLUSIONS: The investigation concludes that CHI in the study region is feasible. However, enrollments are likely to be lower than the stated willingness to join. Still, a CHI scheme should present an interesting financing alternative in rural areas where services are scarce and difficult to sustain.OBJETIVO: El objetivo principal de este estudio fue evaluar la voluntad de los habitantes de El Páramo, una zona rural en el Ecuador, de participar en un seguro de salud comunitario y determinar los factores que influían en dicha voluntad. Otro objetivo fue identificar la comprensión y las actitudes de la poblaci

  16. Predicted carbonation of existing concrete building based on the Indonesian tropical micro-climate

    Science.gov (United States)

    Hilmy, M.; Prabowo, H.

    2018-03-01

    This paper is aimed to predict the carbonation progress based on the previous mathematical model. It shortly explains the nature of carbonation including the processes and effects. Environmental humidity and temperature of the existing concrete building are measured and compared to data from local Meteorological, Climatological, and Geophysical Agency. The data gained are expressed in the form of annual hygrothermal values which will use as the input parameter in carbonation model. The physical properties of the observed building such as its location, dimensions, and structural material used are quantified. These data then utilized as an important input parameter for carbonation coefficients. The relationships between relative humidity and the rate of carbonation established. The results can provide a basis for repair and maintenance of existing concrete buildings and the sake of service life analysis of them.

  17. Data base management system for lymphatic filariasis--a neglected tropical disease.

    Science.gov (United States)

    Upadhyayula, Suryanaryana Murty; Mutheneni, Srinivasa Rao; Kadiri, Madhusudhan Rao; Kumaraswamy, Sriram; Nelaturu, Sarat Chandra Babu

    2012-01-01

    Researchers working in the area of Public Health are being confronted with large volumes of data on various aspects of entomology and epidemiology. To obtain the relevant information out of these data requires particular database management system. In this paper, we have described about the usages of our developed database on lymphatic filariasis. This database application is developed using Model View Controller (MVC) architecture, with MySQL as database and a web based interface. We have collected and incorporated the data on filariasis in the database from Karimnagar, Chittoor, East and West Godavari districts of Andhra Pradesh, India. The importance of this database is to store the collected data, retrieve the information and produce various combinational reports on filarial aspects which in turn will help the public health officials to understand the burden of disease in a particular locality. This information is likely to have an imperative role on decision making for effective control of filarial disease and integrated vector management operations.

  18. Optimization of tropical fruit juice based on sensory and nutritional characteristics

    Directory of Open Access Journals (Sweden)

    Paula Nogueira CURI

    Full Text Available Abstract The objective of this study was, through mixing design and response surface methodology, to optimize a reduced calorie mixed juice of persimmon, orange and pineapple based the sensory and nutritional characteristics. This study also aimed to carry out the survey of the physicochemical characteristics that are desirable in this product. It was found that juice of these fruits, when combined, have better sensory and nutritional characteristics than when isolated. The consumer has a preference for mixed fruit juices made up of orange, pineapple and persimmon that are sweeter and more acidic and regarding color, consumers prefer a juice with less intense red color. According to evaluation, the most recommended mixed juice formulations are 50% pineapple and 50% persimmon, and 33% pineapple, 33% persimmon, and 33% orange.

  19. [Tropical causes of epilepsy].

    Science.gov (United States)

    Carod-Artal, F J

    Eighty-five percent of all epileptics live in tropical regions. Prenatal risk factors, traumatic brain injuries and different parasitic infestations of the central nervous system (CNS) are the reasons behind the high prevalence of epilepsy. This work reviews the main parasitic infestations causing epilepsy in the tropics. Neurocysticercosis is the main cause of focal epilepsy in early adulthood in endemic areas (30-50%). All the phases of cysticerci (viable, transitional and calcified) are associated with epileptic seizures. Anti-cysticercus treatment helps get rid of cysticerci faster and reduces the risk of recurrence of seizures in patients with viable cysts. Symptomatic epilepsy can be the first manifestation of neuroschistosomiasis in patients without any systemic symptoms. The pseudotumoral form can trigger seizures secondary to the presence of granulomas and oedemas in the cerebral cortex. The eggs of Schistosoma japonicum are smaller, reach the CNS more easily and trigger epileptic seizures more frequently. Toxocariasis and sparganosis are other parasitic infestations that can give rise to symptomatic seizures. The risk factors for suffering chronic epilepsy after cerebral malaria are a positive familial history of epilepsy and a history of episodes of fever and cerebral malaria that began with coma or which progressed with multiple, prolonged epileptic seizures. About 20% of patients with cerebral infarction secondary to Chagas disease present late vascular epilepsy as a complication. Very few studies have been conducted to examine the prognosis, risk of recurrence and modification of the natural course of seizures associated with tropical parasitic infestations, except for the case of neurocysticercosis.

  20. Livelihood diversification in tropical coastal communities: a network-based approach to analyzing 'livelihood landscapes'.

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    Joshua E Cinner

    Full Text Available BACKGROUND: Diverse livelihood portfolios are frequently viewed as a critical component of household economies in developing countries. Within the context of natural resources governance in particular, the capacity of individual households to engage in multiple occupations has been shown to influence important issues such as whether fishers would exit a declining fishery, how people react to policy, the types of resource management systems that may be applicable, and other decisions about natural resource use. METHODOLOGY/PRINCIPAL FINDINGS: This paper uses network analysis to provide a novel methodological framework for detailed systemic analysis of household livelihood portfolios. Paying particular attention to the role of natural resource-based occupations such as fisheries, we use network analyses to map occupations and their interrelationships- what we refer to as 'livelihood landscapes'. This network approach allows for the visualization of complex information about dependence on natural resources that can be aggregated at different scales. We then examine how the role of natural resource-based occupations changes along spectra of socioeconomic development and population density in 27 communities in 5 western Indian Ocean countries. Network statistics, including in- and out-degree centrality, the density of the network, and the level of network centralization are compared along a multivariate index of community-level socioeconomic development and a gradient of human population density. The combination of network analyses suggests an increase in household-level specialization with development for most occupational sectors, including fishing and farming, but that at the community-level, economies remained diversified. CONCLUSIONS/SIGNIFICANCE: The novel modeling approach introduced here provides for various types of livelihood portfolio analyses at different scales of social aggregation. Our livelihood landscapes approach provides insights

  1. Data base management system for lymphatic filariasis--a neglected tropical disease.

    Directory of Open Access Journals (Sweden)

    Suryanaryana Murty Upadhyayula

    Full Text Available BACKGROUND: Researchers working in the area of Public Health are being confronted with large volumes of data on various aspects of entomology and epidemiology. To obtain the relevant information out of these data requires particular database management system. In this paper, we have described about the usages of our developed database on lymphatic filariasis. METHODS: This database application is developed using Model View Controller (MVC architecture, with MySQL as database and a web based interface. We have collected and incorporated the data on filariasis in the database from Karimnagar, Chittoor, East and West Godavari districts of Andhra Pradesh, India. CONCLUSION: The importance of this database is to store the collected data, retrieve the information and produce various combinational reports on filarial aspects which in turn will help the public health officials to understand the burden of disease in a particular locality. This information is likely to have an imperative role on decision making for effective control of filarial disease and integrated vector management operations.

  2. Analyses of the influencing factors of soil microbial functional gene diversity in tropical rainforest based on GeoChip 5.0

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    Jing Cong

    2015-09-01

    Full Text Available To examine soil microbial functional gene diversity and causative factors in tropical rainforests, we used a microarray-based metagenomic tool named GeoChip 5.0 to profile it. We found that high microbial functional gene diversity and different soil microbial metabolic potential for biogeochemical processes were considered to exist in tropical rainforest. Soil available nitrogen was the most associated with soil microbial functional gene structure. Here, we mainly describe the experiment design, the data processing, and soil biogeochemical analyses attached to the study in details, which could be published on BMC microbiology Journal in 2015, whose raw data have been deposited in NCBI's Gene Expression Omnibus (accession number GSE69171.

  3. Approach to voxel-based carbon stock quanticiation using LiDAR data in tropical rainforest, Brunei

    Science.gov (United States)

    Kim, Eunji; Piao, Dongfan; Lee, Jongyeol; Lee, Woo-Kyun; Yoon, Mihae; Moon, Jooyeon

    2016-04-01

    Forest is an important means to adapt climate change as the only carbon sink recognized by the international community (KFS 2009). According to the Intergovernmental Panel on Climate Change (IPCC) 5th Assessment Report (AR5), Agriculture, Forestry, and Other Land Use (AFOLU) sectors including forestry contributed 24% of total anthropogenic emissions in 2010 (IPCC 2014; Tubiello et al. 2015). While all sectors excluding AFOLU have increased Greenhouse Gas (GHG) emissions, land use sectors including forestry remains similar level as before due to decreasing deforestation and increasing reforestation. In earlier researches, optical imagery has been applied for analysis (Jakubowski et al. 2013). Optical imagery collects spectral information in 2D. It is difficult to effectively quantify forest stocks, especially in dense forest (Cui et al. 2012). To detect individual trees information from remotely sensed data, Light detection and ranging (LiDAR) has been used (Hyyppäet al. 2001; Persson et al. 2002; Chen et al. 2006). Moreover, LiDAR has the ability to actively acquire vertical tree information such as tree height using geo-registered 3D points (Kwak et al. 2007). In general, however, geo-register 3D point was used with a raster format which contains only 2D information by missing all the 3D data. Therefore, this research aimed to use the volumetric pixel (referred as "voxel") approach using LiDAR data in tropical rainforest, Brunei. By comparing the parameters derived from voxel based LiDAR data and field measured data, we examined the relationships between them for the quantification of forest carbon. This study expects to be more helpful to take advantage of the strategic application of climate change adaption.

  4. Analysis of Tropical Cyclone Tracks in the North Indian Ocean

    Science.gov (United States)

    Patwardhan, A.; Paliwal, M.; Mohapatra, M.

    2011-12-01

    Cyclones are regarded as one of the most dangerous meteorological phenomena of the tropical region. The probability of landfall of a tropical cyclone depends on its movement (trajectory). Analysis of trajectories of tropical cyclones could be useful for identifying potentially predictable characteristics. There is long history of analysis of tropical cyclones tracks. A common approach is using different clustering techniques to group the cyclone tracks on the basis of certain characteristics. Various clustering method have been used to study the tropical cyclones in different ocean basins like western North Pacific ocean (Elsner and Liu, 2003; Camargo et al., 2007), North Atlantic Ocean (Elsner, 2003; Gaffney et al. 2007; Nakamura et al., 2009). In this study, tropical cyclone tracks in the North Indian Ocean basin, for the period 1961-2010 have been analyzed and grouped into clusters based on their spatial characteristics. A tropical cyclone trajectory is approximated as an open curve and described by its first two moments. The resulting clusters have different centroid locations and also differently shaped variance ellipses. These track characteristics are then used in the standard clustering algorithms which allow the whole track shape, length, and location to be incorporated into the clustering methodology. The resulting clusters have different genesis locations and trajectory shapes. We have also examined characteristics such as life span, maximum sustained wind speed, landfall, seasonality, many of which are significantly different across the identified clusters. The clustering approach groups cyclones with higher maximum wind speed and longest life span in to one cluster. Another cluster includes short duration cyclonic events that are mostly deep depressions and significant for rainfall over Eastern and Central India. The clustering approach is likely to prove useful for analysis of events of significance with regard to impacts.

  5. Towards an ecological index for tropical soil quality based on soil macrofauna Em busca de um índice ecológico para a qualidade de solo tropical com base na macrofauna edáfica

    Directory of Open Access Journals (Sweden)

    Esperanza Huerta

    2009-08-01

    Full Text Available The objective of this work was to construct a simple index based on the presence/absence of different groups of soil macrofauna to determine the ecological quality of soils. The index was tested with data from 20 sites in South and Central Tabasco, Mexico, and a positive relation between the model and the field observations was detected. The index showed that diverse agroforestry systems had the highest soil quality index (1.00, and monocrops without trees, such as pineapple, showed the lowest soil quality index (0.08. Further research is required to improve this model for natural systems that have very low earthworm biomass (O objetivo deste trabalho foi construir um índice simples com base na presença/ausência de diferentes grupos da macrofauna edáfica para auxiliar na determinação da qualidade ecológica dos solos. O índice foi testado com dados de 20 locais do sul e centro do Estado de Tabasco, México, e foi observada uma correlação positiva entre o dados gerados pelo modelo e pelas observações de campo. O índice de qualidade de solo mostrou que diversos sistemas agroflorestais tiveram a mais alta qualidade de solo (1,0 e que os monocultivos sem árvores, como o de abacaxi, apresentaram a qualidade de solo mais baixa (0,08. Este modelo precisa ser melhor desenvolvido para ser aplicado eficientemente em sistemas que apresentam naturalmente baixas densidades de minhocas (<10 g m-2 e número elevado de espécies de minhocas (5-7, como ocorre em solos de floresta tropical, cujo índice de qualidade de solo apresentou valores médios (0,5. A aplicação desse índice precisará de um guia ilustrado para os seus usuários. Mais estudos são necessários para testar o seu emprego por fazendeiros.

  6. Forests to fields. Restoring tropical lands to agriculture.

    Science.gov (United States)

    Wood, D

    1993-04-01

    In discussing land use in tropical forest regions, there is an emphasis on the following topics: the need for the expansion of cropping areas, the precedent for use of the tropical forest for cropping based on past use patterns, the pressure from conservationists against cropping, debunking the mythology that forests are "natural" and refuting the claims that forest clearance is not reversible, the archeological evidence of past forest use for agricultural purposes, abandonment of tropical land to forest, and rotation of forest and field. The assumption is that the way to stop food importation is to increase crop production in the tropics. Crop production can be increased through 1) land intensification or clearing new land, 2) output per unit of land increases, or 3) reallocation to agriculture land previously cleared and overgrown with tropical forest. "Temporary" reuse of land, which reverted back to tropical forest, is recommended. This reuse would ease population pressure, and benefit bioconservation, while populations stabilize and further progress is made in international plant breeding. The land would eventually be returned to a forest state. Conservation of tropical forest areas should be accomplished, after an assessment has been made of its former uses. Primary forests need to identified and conversion to farming ceased. Research needs to be directed to understanding the process of past forest regeneration, and to devising cropping systems with longterm viability. The green revolution is unsuitable for traditional cropping systems, is contrary to demands of international funding agencies for sustainability, and is not affordable by most poor farmers. Only .48 million sq. km of closed forest loss was in tropical rainforests; 6.53 million sq. km was lost from temperate forests cleared for intensive small-scale peasant farming. The use of tropical forest land for farming has some benefits; crops in the wetter tropics are perennial, which would "reduce

  7. Design basis tropical cyclone for nuclear power plants

    International Nuclear Information System (INIS)

    1984-01-01

    The general characteristics of tropical cyclones are discussed in this Safety Guide, with particular emphasis on their pressure and wind structures in the light of available data. General methods are given for the evaluation of the relevant parameters of a Probable Maximum Tropical Cyclone (PMTC), which can be used as the Design Basis Tropical Cyclone (DBTC); these parameters then serve as inputs for the derivation of a design basis surge and a design basis wind. A possible method is also given for the evaluation of the PMTC pressure and wind field based on an approach valid primarily for a particular region. This method depends on the results of a theoretical study on the tropical cyclone structure and makes use of a large amount of data, including aircraft reconnaissance observations for 170 most intense tropical cyclones near the coast of Japan, Taiwan and the Philippines for the period 1960-1974, as well as detailed analyses of all the extreme storms along the Gulf of Mexico and the east coast of the USA during 1900-1978, for the determination of the necessary parameters

  8. Height-diameter allometry of tropical forest trees

    Science.gov (United States)

    T.R. Feldpausch; L. Banin; O.L. Phillips; T.R. Baker; S.L. Lewis; C.A. Quesada; K. Affum-Baffoe; E.J.M.M. Arets; N.J. Berry; M. Bird; E.S. Brondizio; P de Camargo; J. Chave; G. Djagbletey; T.F. Domingues; M. Drescher; P.M. Fearnside; M.B. Franca; N.M. Fyllas; G. Lopez-Gonzalez; A. Hladik; N. Higuchi; M.O. Hunter; Y. Iida; K.A. Salim; A.R. Kassim; M. Keller; J. Kemp; D.A. King; J.C. Lovett; B.S. Marimon; B.H. Marimon-Junior; E. Lenza; A.R. Marshall; D.J. Metcalfe; E.T.A. Mitchard; E.F. Moran; B.W. Nelson; R. Nilus; E.M. Nogueira; M. Palace; S. Patiño; K.S.-H. Peh; M.T. Raventos; J.M. Reitsma; G. Saiz; F. Schrodt; B. Sonke; H.E. Taedoumg; S. Tan; L. White; H. Woll; J. Lloyd

    2011-01-01

    Tropical tree height-diameter (H:D) relationships may vary by forest type and region making large-scale estimates of above-ground biomass subject to bias if they ignore these differences in stem allometry. We have therefore developed a new global tropical forest database consisting of 39 955 concurrent H and D measurements encompassing 283 sites in 22 tropical...

  9. A photostationary state analysis of the NO2-NO system based on airborne observations from the subtropical/tropical North and South Atlantic

    Science.gov (United States)

    Davis, D. D.; Chen, G.; Chameides, W.; Bradshaw, J.; Sandholm, S.; Rodgers, M.; Schendal, J.; Madronich, S.; Sachse, G.; Gregory, G.

    1993-01-01

    The Chemical Instrumentation Test and Evaluation 3 (CITE 3) NO-NO2 database has provided a unique opportunity to examine important aspects of tropospheric photochemistry as related to the rapid cycling between NO and NO2. Our results suggest that when quantitative testing of this photochemical system is based on airborne field data, extra precautions may need to be taken in the analysis. This was particularly true in the CITE 3 data analysis where different regional environments produced quite different results when evaluating the photochemical test ratio (NO2)(sub expt)/(NO2)(sub calc), designated here as R(sub E)/R(sub C). The quantity (NO2)(sub Calc) was evaluated using the following photostationary state expression: (NO2)(sub Calc) = k(sub 1)(O3) + k(sub 4)(HO2) + k(sub 5)(CH3O2) + k(sub 6)(RO2))(NO)(sub Expt)/J(sub 2). The four most prominent regional environmental data sets identified in this analysis were those labeled here as free-tropospheric northern hemisphere (FTNH), free-tropospheric tropical northern hemisphere (FTTNH), free-tropospheric southern hemisphere (FTSH), and tropical-marine boundary layer (plume) (TMBL(P)). The respective R(sub E)/R(sub C) mean and median values for these four data subsets were 1.74, 1.69; 3.00, 2.79; 1.01, 0.97; and 0.99, 0.94. Of the four data subsets listed, the two that were statistically the most robust were FTNH and FTSH; for these the respective R(sub E)/R(sub C) mean and standard deviation of the mean values were 1.74 +/- 0.07 and 1.01 +/- 0.04. The FTSH observations were in good agreement with theory, whereas those from the FTNH data set were in significant disagreement. An examination of the critical photochemical parameters O3, UV(zenith), NO, NO2, and non-methane hydrocarbons (NMHCs) for these two databases indicated that the most likely source of the R(sub E)/R(sub C) bias in the FTNH results was the presence of a systematic error in the observational data rather than a shortening in our understanding of

  10. Nutrient stocks of short-term fallows on high base status soils in the humid tropics of Papua New Guinea

    NARCIS (Netherlands)

    Hartemink, A.E.

    2004-01-01

    In order to understand nutrient dynamics in tropical farming systems with fallows, it is necessary to assess changes in nutrient stocks in plants, litter and soils. Nutrient stocks (soil, above ground biomass, litter) were assessed of one-year old fallows with Piper aduncum, Gliricidia sepium and

  11. SAMIRA - SAtellite based Monitoring Initiative for Regional Air quality

    Science.gov (United States)

    Schneider, Philipp; Stebel, Kerstin; Ajtai, Nicolae; Diamandi, Andrei; Horalek, Jan; Nicolae, Doina; Stachlewska, Iwona; Zehner, Claus

    2016-04-01

    Here, we present a new ESA-funded project entitled Satellite based Monitoring Initiative for Regional Air quality (SAMIRA), which aims at improving regional and local air quality monitoring through synergetic use of data from present and upcoming satellites, traditionally used in situ air quality monitoring networks and output from chemical transport models. Through collaborative efforts in four countries, namely Romania, Poland, the Czech Republic and Norway, all with existing air quality problems, SAMIRA intends to support the involved institutions and associated users in their national monitoring and reporting mandates as well as to generate novel research in this area. Despite considerable improvements in the past decades, Europe is still far from achieving levels of air quality that do not pose unacceptable hazards to humans and the environment. Main concerns in Europe are exceedances of particulate matter (PM), ground-level ozone, benzo(a)pyrene (BaP) and nitrogen dioxide (NO2). While overall sulfur dioxide (SO2) emissions have decreased in recent years, regional concentrations can still be high in some areas. The objectives of SAMIRA are to improve algorithms for the retrieval of hourly aerosol optical depth (AOD) maps from SEVIRI, and to develop robust methods for deriving column- and near-surface PM maps for the study area by combining satellite AOD with information from regional models. The benefit to existing monitoring networks (in situ, models, satellite) by combining these datasets using data fusion methods will be tested for satellite-based NO2, SO2, and PM/AOD. Furthermore, SAMIRA will test and apply techniques for downscaling air quality-related EO products to a spatial resolution that is more in line with what is generally required for studying urban and regional scale air quality. This will be demonstrated for a set of study sites that include the capitals of the four countries and the highly polluted areas along the border of Poland and the

  12. Ozone in the Tropical Troposphere

    NARCIS (Netherlands)

    Peters, Wouter

    2002-01-01

    The aim of the research presented here is to acquire knowledge of the past, present, and future composition, stability, sensitivity, and variability of the troposphere. We focus mostly on the tropical regions because it has received little attention so far, measurements here are scarce, and large

  13. Calculation of Individual Tree Water Use in a Bornean Tropical Rain Forest Using Individual-Based Dynamic Vegetation Model SEIB-DGVM

    Science.gov (United States)

    Nakai, T.; Kumagai, T.; Saito, T.; Matsumoto, K.; Kume, T.; Nakagawa, M.; Sato, H.

    2015-12-01

    Bornean tropical rain forests are among the moistest biomes of the world with abundant rainfall throughout the year, and considered to be vulnerable to a change in the rainfall regime; e.g., high tree mortality was reported in such forests induced by a severe drought associated with the ENSO event in 1997-1998. In order to assess the effect (risk) of future climate change on eco-hydrology in such tropical rain forests, it is important to understand the water use of trees individually, because the vulnerability or mortality of trees against climate change can depend on the size of trees. Therefore, we refined the Spatially Explicit Individual-Based Dynamic Global Vegetation Model (SEIB-DGVM) so that the transpiration and its control by stomata are calculated for each individual tree. By using this model, we simulated the transpiration of each tree and its DBH-size dependency, and successfully reproduced the measured data of sap flow of trees and eddy covariance flux data obtained in a Bornean lowland tropical rain forest in Lambir Hills National Park, Sarawak, Malaysia.

  14. IMPROVING MANAGEMENT QUALITY BASED ON A REGIONAL INNOVATION DEVELOPMENT BY THE EXAMPLE OF THE SAMARA REGION: ESTIMATE INDICATORS

    Directory of Open Access Journals (Sweden)

    Robert R. Bakhtiev

    2013-01-01

    Full Text Available The article considers the basic ways of improving management quality via a regional innovation development based on the correlation analysis. The necessity of formation of qualitative information interaction of parts of a regional innovation system is proved. It allows creating more effective innovation process in the region.

  15. The internal transcribed spacer (ITS region and trnH-psbA [corrected] are suitable candidate loci for DNA barcoding of tropical tree species of India.

    Directory of Open Access Journals (Sweden)

    Abhinandan Mani Tripathi

    Full Text Available DNA barcoding as a tool for species identification has been successful in animals and other organisms, including certain groups of plants. The exploration of this new tool for species identification, particularly in tree species, is very scanty from biodiversity-rich countries like India. rbcL and matK are standard barcode loci while ITS, and trnH-psbA are considered as supplementary loci for plants.Plant barcode loci, namely, rbcL, matK, ITS, trnH-psbA, and the recently proposed ITS2, were tested for their efficacy as barcode loci using 300 accessions of tropical tree species. We tested these loci for PCR, sequencing success, and species discrimination ability using three methods. rbcL was the best locus as far as PCR and sequencing success rate were concerned, but not for the species discrimination ability of tropical tree species. ITS and trnH-psbA were the second best loci in PCR and sequencing success, respectively. The species discrimination ability of ITS ranged from 24.4 percent to 74.3 percent and that of trnH-psbA was 25.6 percent to 67.7 percent, depending upon the data set and the method used. matK provided the least PCR success, followed by ITS2 (59. 0%. Species resolution by ITS2 and rbcL ranged from 9.0 percent to 48.7 percent and 13.2 percent to 43.6 percent, respectively. Further, we observed that the NCBI nucleotide database is poorly represented by the sequences of barcode loci studied here for tree species.Although a conservative approach of a success rate of 60-70 percent by both ITS and trnH-psbA may not be considered as highly successful but would certainly help in large-scale biodiversity inventorization, particularly for tropical tree species, considering the standard success rate of plant DNA barcode program reported so far. The recommended matK and rbcL primers combination may not work in tropical tree species as barcode markers.

  16. Tropical forests. Nettai no shinrin

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, I [Kyoto Univ., Kyoto (Japan)

    1991-11-05

    It was in 1950s when felling of tropical forests started in earnest, in 1970s felling of forest trees in Southeast Asia reached its peak and the destnation of exportation of most of them was Japan. Besides, among the present overseas development assistance projects (ODA) of Japan, her role to be played in connection with tropical forests is not small and its funds, which surpass by far the budget for forestry of the United Nations Food and Agriculture Organization (FAO), are aiding cooperation projects on forestry in many places in the world. Nevertheless, in Japan, the understanding of tropical forests is insufficient and its realities have not been known. In this article, based on the experience and knowledge of the author who stayed in Kalimantan, various kinds of problems concerning tropical forests are explained, the realities are introduced on information, well trained people, funds and philosophy which are far short in pursuance of the problems of tropical forests. Furthermore, as the issues hereafter, such proposals on tropical forests are made as protection of natural forests, planned operation in respecting self renewal ability of the secondary forests and afforestation of alang-alang grassy plains resulted from the failure of burning felled trees and grasses for making the land arable. 1 ref..

  17. Object-based landslide detection in different geographic regions

    Science.gov (United States)

    Friedl, Barbara; Hölbling, Daniel; Eisank, Clemens; Blaschke, Thomas

    2015-04-01

    Landslides occur in almost all mountainous regions of the world and rank among the most severe natural hazards. In the last decade - according to the world disaster report 2014 published by the International Federation of Red Cross and Red Crescent Societies (IRFC) - more than 9.000 people were killed by mass movements, more than 3.2 million people were affected and the total amount of disaster estimated damage accounts to more than 1.700 million US dollars. The application of remote sensing data for mapping landslides can contribute to post-disaster reconstruction or hazard mitigation, either by providing rapid information about the spatial distribution and location of landslides in the aftermath of triggering events or by creating and updating landslide inventories. This is especially valid for remote and inaccessible areas, where information on landslides is often lacking. However, reliable methods are needed for extracting timely and relevant information about landslides from remote sensing data. In recent years, novel methods such as object-based image analysis (OBIA) have been successfully employed for semi-automated landslide mapping. Several studies revealed that OBIA frequently outperforms pixel-based approaches, as a range of image object properties (spectral, spatial, morphometric, contextual) can be exploited during the analysis. However, object-based methods are often tailored to specific study areas, and thus, the transferability to regions with different geological settings, is often limited. The present case study evaluates the transferability and applicability of an OBIA approach for landslide detection in two distinct regions, i.e. the island of Taiwan and Austria. In Taiwan, sub-areas in the Baichi catchment in the North and in the Huaguoshan catchment in the southern-central part of the island are selected; in Austria, landslide-affected sites in the Upper Salzach catchment in the federal state of Salzburg are investigated. For both regions

  18. Tropical convection regimes in climate models: evaluation with satellite observations

    Science.gov (United States)

    Steiner, Andrea K.; Lackner, Bettina C.; Ringer, Mark A.

    2018-04-01

    High-quality observations are powerful tools for the evaluation of climate models towards improvement and reduction of uncertainty. Particularly at low latitudes, the most uncertain aspect lies in the representation of moist convection and interaction with dynamics, where rising motion is tied to deep convection and sinking motion to dry regimes. Since humidity is closely coupled with temperature feedbacks in the tropical troposphere, a proper representation of this region is essential. Here we demonstrate the evaluation of atmospheric climate models with satellite-based observations from Global Positioning System (GPS) radio occultation (RO), which feature high vertical resolution and accuracy in the troposphere to lower stratosphere. We focus on the representation of the vertical atmospheric structure in tropical convection regimes, defined by high updraft velocity over warm surfaces, and investigate atmospheric temperature and humidity profiles. Results reveal that some models do not fully capture convection regions, particularly over land, and only partly represent strong vertical wind classes. Models show large biases in tropical mean temperature of more than 4 K in the tropopause region and the lower stratosphere. Reasonable agreement with observations is given in mean specific humidity in the lower to mid-troposphere. In moist convection regions, models tend to underestimate moisture by 10 to 40 % over oceans, whereas in dry downdraft regions they overestimate moisture by 100 %. Our findings provide evidence that RO observations are a unique source of information, with a range of further atmospheric variables to be exploited, for the evaluation and advancement of next-generation climate models.

  19. Evidence based guidelines for complex regional pain syndrome type 1

    Directory of Open Access Journals (Sweden)

    Thomassen-Hilgersom Ilona L

    2010-03-01

    Full Text Available Abstract Background Treatment of complex regional pain syndrome type I (CRPS-I is subject to discussion. The purpose of this study was to develop multidisciplinary guidelines for treatment of CRPS-I. Method A multidisciplinary task force graded literature evaluating treatment effects for CRPS-I according to their strength of evidence, published between 1980 to June 2005. Treatment recommendations based on the literature findings were formulated and formally approved by all Dutch professional associations involved in CRPS-I treatment. Results For pain treatment, the WHO analgesic ladder is advised with the exception of strong opioids. For neuropathic pain, anticonvulsants and tricyclic antidepressants may be considered. For inflammatory symptoms, free-radical scavengers (dimethylsulphoxide or acetylcysteine are advised. To promote peripheral blood flow, vasodilatory medication may be considered. Percutaneous sympathetic blockades may be used to increase blood flow in case vasodilatory medication has insufficient effect. To decrease functional limitations, standardised physiotherapy and occupational therapy are advised. To prevent the occurrence of CRPS-I after wrist fractures, vitamin C is recommended. Adequate perioperative analgesia, limitation of operating time, limited use of tourniquet, and use of regional anaesthetic techniques are recommended for secondary prevention of CRPS-I. Conclusions Based on the literature identified and the extent of evidence found for therapeutic interventions for CRPS-I, we conclude that further research is needed into each of the therapeutic modalities discussed in the guidelines.

  20. Characteristics of multiple tropopauses in the tropics

    Science.gov (United States)

    Mehta, Sanjay Kumar; Ratnam Madineni, Venkat; Krishna Murthy, B. V.

    The characteristics of multiple tropopauses (MTs) in the tropics are studied using radiosonde data from 5 stations (Truk,Rochambeau, Singapore, Seychelles and Darwin) in the tropical belt during 1999 to 2008 and COSMIC GPS RO data during 2006-2008. In this study we emphasized the limitations of the WMO criteria for identifying the MTs and evolved an alternative criterion to effectively delineate MTs over tropical region. The current method is based on cold point tropopause (CPT) and points of inflections in the temperature profile rather than lapse rate as in WMO criteria. The points of inflection can occur both below and above the CPT. The one which occurs below the CPT is designated as the lower tropopause (LT) and those occurring above the CPT as second tropopause (ST) and third tropopause (TT) according to their heights of occurrence with CPT as the first tropopause. The percentage occurrences (25-50) of MTs are observed to be higher using the current method than by the WMO criteria (10-30). There is significant seasonal variation in the LT, CPT and ST temperatures (heights) with lower (higher) values occurring in the Northern Hemisphere winter. While the CPT temperatures are lowest at the equator the CPT heights are not highest at the equator. The occurrences of MTs are higher over equator and decrease away towards higher latitudes in the tropics. Longitudinal variation of the MTs is observed with relatively high occurrences during NH summer season over placeIndian Ocean. The equatorial minimum in the CPT temperature is broader and colder in the eastern hemisphere than the western hemisphere It is found that MTs can either occur on consecutive days in groups or on isolated days. The plausible causative mechanisms will be presented in the conference.

  1. Dendrochronology in the dry tropics: the Ethiopian case

    NARCIS (Netherlands)

    Wils, T.; Sass-Klaassen, U.; Eshetu, Z.; Bräuning, A.; Gebrenirstos, A.; Couralet, C.; Robertson, I.; Touchan, R.; Koprowski, M.; Conway, D.; Briffa, K.R.; Beeckman, H.

    2011-01-01

    Dendrochronology is developing outside temperate and boreal regions. Over the past decade substantial progress has been made in Mediterranean and wet tropical regions. However, research in dry tropical regions, notably those of sub-Saharan Africa, has remained fragmentary. Here, we try to identify

  2. AGROECOLOGY AND CLIMATE CHANGE IN THE SEMIARID TROPICS

    Directory of Open Access Journals (Sweden)

    Guillermo Gamarra-Rojas

    2017-04-01

    Full Text Available This article makes a theoretical and, to a certain extent, propositional reflection on the conceptions, assumptions and evidences of climate change in the tropics, with emphasis on the Brazilian semiarid region. The contributions of agriculture to climate change are presented and the impacts of climate change on family agriculture in the semiarid region are analyzed. Evidence of mitigation and adaptation in agroecological systems of the semiarid region is presented and an outline of an agenda of the sector based on the commitments assumed by the country and the needs of mitigation and adaptation is provided.

  3. The environmental influence on tropical cyclone precipitation

    Science.gov (United States)

    Rodgers, Edward B.; Baik, Jong-Jin; Pierce, Harold F.

    1994-01-01

    The intensity, spatial, and temporal changes in precipitation were examined in three North Atlantic hurricanes during 1989 (Dean, Gabrielle, and Hugo) using precipitation estimates made from Special Sensor Microwave/Imager (SSM/I) measurements. In addition, analyses from a barotropic hurricane forecast model and the European Centre for Medium-Range Weather Forecast model were used to examine the relationship between the evolution of the precipitation in these tropical cyclones and external forcing. The external forcing parameters examined were (1) mean climatological sea surface temperatures, (2) vertical wind shear, (3) environmental tropospheric water vapor flux, and (4) upper-tropospheric eddy relative angular momentum flux convergence. The analyses revealed that (1) the SSM/I precipitation estimates were able to delineate and monitor convective ring cycles similar to those observed with land-based and aircraft radar and in situ measurements; (2) tropical cyclone intensification was observed to occur when these convective rings propagated into the inner core of these systems (within 111 km of the center) and when the precipitation rates increased; (3) tropical cyclone weakening was observed to occur when these inner-core convective rings dissipated; (4) the inward propagation of the outer convective rings coincided with the dissipation of the inner convective rings when they came within 55 km of each other; (5) in regions with the combined warm sea surface temperatures (above 26 C) and low vertical wind shear (less than 5 m/s), convective rings outside the region of strong lower-tropospheric inertial stability could be initiated by strong surges of tropospheric moisture, while convective rings inside the region of strong lower-tropospheric inertial stability could be enhanced by upper-tropospheric eddy relative angular momentum flux convergence.

  4. Impacts of climate and land use on N2 O and CH4 fluxes from tropical ecosystems in the Mt. Kilimanjaro region, Tanzania.

    Science.gov (United States)

    Gütlein, Adrian; Gerschlauer, Friederike; Kikoti, Imani; Kiese, Ralf

    2018-03-01

    In this study, we quantify the impacts of climate and land use on soil N 2 O and CH 4 fluxes from tropical forest, agroforest, arable and savanna ecosystems in Africa. To do so, we measured greenhouse gases (GHG) fluxes from 12 different ecosystems along climate and land-use gradients at Mt. Kilimanjaro, combining long-term in situ chamber and laboratory soil core incubation techniques. Both methods showed similar patterns of GHG exchange. Although there were distinct differences from ecosystem to ecosystem, soils generally functioned as net sources and sinks for N 2 O and CH 4 respectively. N 2 O emissions correlated positively with soil moisture and total soil nitrogen content. CH 4 uptake rates correlated negatively with soil moisture and clay content and positively with SOC. Due to moderate soil moisture contents and the dominance of nitrification in soil N turnover, N 2 O emissions of tropical montane forests were generally low (<1.2 kg N ha -1  year -1 ), and it is likely that ecosystem N losses are driven instead by nitrate leaching (~10 kg N ha -1  year -1 ). Forest soils with well-aerated litter layers were a significant sink for atmospheric CH 4 (up to 4 kg C ha -1  year -1 ) regardless of low mean annual temperatures at higher elevations. Land-use intensification significantly increased the soil N 2 O source strength and significantly decreased the soil CH 4 sink. Compared to decreases in aboveground and belowground carbon stocks enhanced soil non-CO 2 GHG emissions following land-use conversion from tropical forests to homegardens and coffee plantations were only a small factor in the total GHG budget. However, due to lower ecosystem carbon stock changes, enhanced N 2 O emissions significantly contributed to total GHG emissions following conversion of savanna into grassland and particularly maize. Overall, we found that the protection and sustainable management of aboveground and belowground carbon and nitrogen stocks of agroforestry and

  5. Economic and Biological Values for Pasture-Based Dairy Cattle Porduction Systems and their Application in Genetic Improvement in the Tropics

    DEFF Research Database (Denmark)

    Wahinya, P K; Otieno, Tobias Okeno; Kosgey, I S

    2015-01-01

    estimated under fixed herd (FH) and pasture (FP) production circumstances assuming milk marketing based on volume, and volume and butter fat. Further, economic values were estimated involving risk using the Arrow Pratt coefficients at two levels. For the former economic values for the traits ranged from KSh...... during the estimation of economic values. Genetic improvements targeting MY and growth traits would be recommended to production system with unlimited feed supply for profit maximization. However, since dairy production systems in the tropics are characterised by feed scarcity, fixing the herd...

  6. Torrent classification - Base of rational management of erosive regions

    International Nuclear Information System (INIS)

    Gavrilovic, Zoran; Stefanovic, Milutin; Milovanovic, Irina; Cotric, Jelena; Milojevic, Mileta

    2008-01-01

    A complex methodology for torrents and erosion and the associated calculations was developed during the second half of the twentieth century in Serbia. It was the 'Erosion Potential Method'. One of the modules of that complex method was focused on torrent classification. The module enables the identification of hydro graphic, climate and erosion characteristics. The method makes it possible for each torrent, regardless of its magnitude, to be simply and recognizably described by the 'Formula of torrentially'. The above torrent classification is the base on which a set of optimisation calculations is developed for the required scope of erosion-control works and measures, the application of which enables the management of significantly larger erosion and torrential regions compared to the previous period. This paper will present the procedure and the method of torrent classification.

  7. Torrent classification - Base of rational management of erosive regions

    Energy Technology Data Exchange (ETDEWEB)

    Gavrilovic, Zoran; Stefanovic, Milutin; Milovanovic, Irina; Cotric, Jelena; Milojevic, Mileta [Institute for the Development of Water Resources ' Jaroslav Cerni' , 11226 Beograd (Pinosava), Jaroslava Cernog 80 (Serbia)], E-mail: gavrilovicz@sbb.rs

    2008-11-01

    A complex methodology for torrents and erosion and the associated calculations was developed during the second half of the twentieth century in Serbia. It was the 'Erosion Potential Method'. One of the modules of that complex method was focused on torrent classification. The module enables the identification of hydro graphic, climate and erosion characteristics. The method makes it possible for each torrent, regardless of its magnitude, to be simply and recognizably described by the 'Formula of torrentially'. The above torrent classification is the base on which a set of optimisation calculations is developed for the required scope of erosion-control works and measures, the application of which enables the management of significantly larger erosion and torrential regions compared to the previous period. This paper will present the procedure and the method of torrent classification.

  8. The Watinglo mandible: a second terminal Pleistocene Homo sapiens fossil from tropical Sahul with a test on existing models for the human settlement of the region.

    Science.gov (United States)

    Bulbeck, D; O'Connor, S

    2011-02-01

    This paper analyses a fossil human mandible, dated to circa 10ka, from Watinglo rockshelter on the north coast of Papua New Guinea. The fossil is metrically and morphologically similar to male mandibles of recent Melanesians and Australian Aborigines. It is distinguished from Kow Swamp and Coobool Creek male mandibles (Murray Valley, terminal Pleistocene) by being smaller and having different shape characteristics, as well as smaller teeth and a slower rate of tooth wear. It pairs with the Liang Lemdubu female (Late Glacial Maximum, Aru Islands) in suggesting that the morphology of the terminal Pleistocene inhabitants of tropical Sahul was gracile compared to their contemporaries within the southern Murray drainage. An explanatory scenario for this morphological contrast is developed in the context of the Homo sapiens early fossil record, Australasian mtDNA evidence, terminal Pleistocene climatic variation, and the possibility of multiple entry points into Sahul. Copyright © 2010 Elsevier GmbH. All rights reserved.

  9. Regional Analysis of Remote Sensing Based Evapotranspiration Information

    Science.gov (United States)

    Geli, H. M. E.; Hain, C.; Anderson, M. C.; Senay, G. B.

    2017-12-01

    Recent research findings on modeling actual evapotranspiration (ET) using remote sensing data and methods have proven the ability of these methods to address wide range of hydrological and water resources issues including river basin water balance for improved water resources management, drought monitoring, drought impact and socioeconomic responses, agricultural water management, optimization of land-use for water conservations, water allocation agreement among others. However, there is still a critical need to identify appropriate type of ET information that can address each of these issues. The current trend of increasing demand for water due to population growth coupled with variable and limited water supply due to drought especially in arid and semiarid regions with limited water supply have highlighted the need for such information. To properly address these issues different spatial and temporal resolutions of ET information will need to be used. For example, agricultural water management applications require ET information at field (30-m) and daily time scales while for river basin hydrologic analysis relatively coarser spatial and temporal scales can be adequate for such regional applications. The objective of this analysis is to evaluate the potential of using an integrated ET information that can be used to address some of these issues collectively. This analysis will highlight efforts to address some of the issues that are applicable to New Mexico including assessment of statewide water budget as well as drought impact and socioeconomic responses which all require ET information but at different spatial and temporal scales. This analysis will provide an evaluation of four remote sensing based ET models including ALEXI, DisALEXI, SSEBop, and SEBAL3.0. The models will be compared with ground-based observations from eddy covariance towers and water balance calculations. Remote sensing data from Landsat, MODIS, and VIIRS sensors will be used to provide ET

  10. Warm Water Pools of the Western Caribbean and Eastern Tropical Pacific: Their Influence on Intraseasonal Rainfall Regimes and Tropical Storm Activity in Mexico

    Science.gov (United States)

    Douglas, A. V.; Englehart, P. J.

    2007-05-01

    A dipole in tropical cyclone development between the Caribbean and the eastern tropical Pacific will be examined relative to its affect on southern Mexican rainfall. With the change over in the AMO and PDO in 1994 and 1998, respectively, tropical storm genesis has been increasing in the Caribbean while declining in the tropical east Pacific. This dipole in tropical cyclone development appears to be related to changes in the pre storm season heat content of the two ocean basins (data Scripps Institution of Oceanography). Preliminary work indicates that if the Caribbean is warmer than the Pacific by late May the dipole will be accentuated with a pronounced decrease in tropical storms in the east Pacific with an early and prolonged season in the Caribbean. In recent years there appears to have been an increase in the intensity and duration of midsummer drought (Canicula) in Mexico associated with changes in the PDO and AMO. These long term ocean oscillations appear to control the dipole in the strength of the Caribbean and East Pacific warm pools. Mid summer drought is a normal occurrence in much of Mexico and Central America, but the intensified droughts of the recent period have stressed the agricultural community of the region. Based on preliminary work, it appears that the recent increased frequency of midsummer drought can be linked to a shift in the warmest pool from the East Pacific to the Caribbean.

  11. Enhancement of Tropical Land Cover Mapping with Wavelet-Based Fusion and Unsupervised Clustering of SAR and Landsat Image Data

    Science.gov (United States)

    LeMoigne, Jacqueline; Laporte, Nadine; Netanyahuy, Nathan S.; Zukor, Dorothy (Technical Monitor)

    2001-01-01

    The characterization and the mapping of land cover/land use of forest areas, such as the Central African rainforest, is a very complex task. This complexity is mainly due to the extent of such areas and, as a consequence, to the lack of full and continuous cloud-free coverage of those large regions by one single remote sensing instrument, In order to provide improved vegetation maps of Central Africa and to develop forest monitoring techniques for applications at the local and regional scales, we propose to utilize multi-sensor remote sensing observations coupled with in-situ data. Fusion and clustering of multi-sensor data are the first steps towards the development of such a forest monitoring system. In this paper, we will describe some preliminary experiments involving the fusion of SAR and Landsat image data of the Lope Reserve in Gabon. Similarly to previous fusion studies, our fusion method is wavelet-based. The fusion provides a new image data set which contains more detailed texture features and preserves the large homogeneous regions that are observed by the Thematic Mapper sensor. The fusion step is followed by unsupervised clustering and provides a vegetation map of the area.

  12. Characteristics of smoke emissions from biomass fires of the Amazon region--Base-A experiment

    International Nuclear Information System (INIS)

    Ward, D.E.; Setzer, A.W.; Kaufman, Y.J.; Rasmussen, R.A.

    1991-01-01

    An airborne sampling system was used to collect grab samples of smokes for analysis of both in-plume smoke characteristics and ambient air in Brazil. In addition to the emission measurements, the chemical composition of the forest biomass burned by one fire in the Amazon region of Brazil was compared to the fuel composition for biomass burned in North America. The limited data set suggests that combustion efficiencies for tropical biomass combustion are higher than those of temperature forest fuels, as are emission factors for carbon dioxide

  13. Fungal radiation in the Cape Floristic Region: an analysis based on Gondwanamyces and Ophiostoma.

    Science.gov (United States)

    Roets, F; Wingfield, M J; Crous, P W; Dreyer, L L

    2009-04-01

    The Cape Floristic Region (CFR) displays high levels of plant diversity and endemism, and has received focused botanical systematic attention. In contrast, fungal diversity patterns and co-evolutionary processes in this region have barely been investigated. Here we reconstruct molecular phylogenies using the ITS and beta-tubulin gene regions of the ophiostomatoid fungi Gondwanamyces and Ophiostoma associated with southern African Protea species. Results indicate that they evolved in close association with Protea. In contrast to Protea, Ophiostoma species migrated to the CFR from tropical and subtropical Africa, where they underwent subsequent radiation. In both Gondwanamyces and Ophiostoma vector arthropods probably facilitated long-distance migration and shorter-distance dispersal. Although ecological parameters shaped most associations between ophiostomatoid fungi and Protea, there is congruence between fungal-host-associations and the systematic classification of Protea. These results confirm that the entire biotic environment must be considered in order to understand diversity and evolution in the CFR as a whole.

  14. Comparing parameterized versus measured microphysical properties of tropical convective cloud bases during the ACRIDICON–CHUVA campaign

    Directory of Open Access Journals (Sweden)

    R. C. Braga

    2017-06-01

    Full Text Available The objective of this study is to validate parameterizations that were recently developed for satellite retrievals of cloud condensation nuclei supersaturation spectra, NCCN(S, at cloud base alongside more traditional parameterizations connecting NCCN(S with cloud base updrafts and drop concentrations. This was based on the HALO aircraft measurements during the ACRIDICON–CHUVA campaign over the Amazon region, which took place in September 2014. The properties of convective clouds were measured with a cloud combination probe (CCP, a cloud and aerosol spectrometer (CAS-DPOL, and a CCN counter onboard the HALO aircraft. An intercomparison of the cloud drop size distributions (DSDs and the cloud water content (CWC derived from the different instruments generally shows good agreement within the instrumental uncertainties. To this end, the directly measured cloud drop concentrations (Nd near cloud base were compared with inferred values based on the measured cloud base updraft velocity (Wb and NCCN(S spectra. The measurements of Nd at cloud base were also compared with drop concentrations (Na derived on the basis of an adiabatic assumption and obtained from the vertical evolution of cloud drop effective radius (re above cloud base. The measurements of NCCN(S and Wb reproduced the observed Nd within the measurements uncertainties when the old (1959 Twomey's parameterization was used. The agreement between the measured and calculated Nd was only within a factor of 2 with attempts to use cloud base S, as obtained from the measured Wb, Nd, and NCCN(S. This underscores the yet unresolved challenge of aircraft measurements of S in clouds. Importantly, the vertical evolution of re with height reproduced the observation-based nearly adiabatic cloud base drop concentrations, Na. The combination of these results provides aircraft observational support for the various components of the satellite-retrieved methodology that was recently developed to

  15. Defect detection based on extreme edge of defective region histogram

    Directory of Open Access Journals (Sweden)

    Zouhir Wakaf

    2018-01-01

    Full Text Available Automatic thresholding has been used by many applications in image processing and pattern recognition systems. Specific attention was given during inspection for quality control purposes in various industries like steel processing and textile manufacturing. Automatic thresholding problem has been addressed well by the commonly used Otsu method, which provides suitable results for thresholding images based on a histogram of bimodal distribution. However, the Otsu method fails when the histogram is unimodal or close to unimodal. Defects have different shapes and sizes, ranging from very small to large. The gray-level distributions of the image histogram can vary between unimodal and multimodal. Furthermore, Otsu-revised methods, like the valley-emphasis method and the background histogram mode extents, which overcome the drawbacks of the Otsu method, require preprocessing steps and fail to use the general threshold for multimodal defects. This study proposes a new automatic thresholding algorithm based on the acquisition of the defective region histogram and the selection of its extreme edge as the threshold value to segment all defective objects in the foreground from the image background. To evaluate the proposed defect-detection method, common standard images for experimentation were used. Experimental results of the proposed method show that the proposed method outperforms the current methods in terms of defect detection.

  16. Human body region enhancement method based on Kinect infrared imaging

    Science.gov (United States)

    Yang, Lei; Fan, Yubo; Song, Xiaowei; Cai, Wenjing

    2016-10-01

    To effectively improve the low contrast of human body region in the infrared images, a combing method of several enhancement methods is utilized to enhance the human body region. Firstly, for the infrared images acquired by Kinect, in order to improve the overall contrast of the infrared images, an Optimal Contrast-Tone Mapping (OCTM) method with multi-iterations is applied to balance the contrast of low-luminosity infrared images. Secondly, to enhance the human body region better, a Level Set algorithm is employed to improve the contour edges of human body region. Finally, to further improve the human body region in infrared images, Laplacian Pyramid decomposition is adopted to enhance the contour-improved human body region. Meanwhile, the background area without human body region is processed by bilateral filtering to improve the overall effect. With theoretical analysis and experimental verification, the results show that the proposed method could effectively enhance the human body region of such infrared images.

  17. Fiducial-based registration with a touchable region model.

    Science.gov (United States)

    Kim, Sungmin; Kazanzides, Peter

    2017-02-01

    Image-guided surgery requires registration between an image coordinate system and an intraoperative coordinate system that is typically referenced to a tracking device. In fiducial-based registration methods, this is achieved by localizing points (fiducials) in each coordinate system. Often, both localizations are performed manually, first by picking a fiducial point in the image and then by using a hand-held tracked pointer to physically touch the corresponding fiducial on the patient. These manual procedures introduce localization error that is user-dependent and can significantly decrease registration accuracy. Thus, there is a need for a registration method that is tolerant of imprecise fiducial localization in the preoperative and intraoperative phases. We propose the iterative closest touchable point (ICTP) registration framework, which uses model-based localization and a touchable region model. This method consists of three stages: (1) fiducial marker localization in image space, using a fiducial marker model, (2) initial registration with paired-point registration, and (3) fine registration based on the iterative closest point method. We perform phantom experiments with a fiducial marker design that is commonly used in neurosurgery. The results demonstrate that ICTP can provide accuracy improvements compared to the standard paired-point registration method that is widely used for surgical navigation and surgical robot systems, especially in cases where the surgeon introduces large localization errors. The results demonstrate that the proposed method can reduce the effect of the surgeon's localization performance on the accuracy of registration, thereby producing more consistent and less user-dependent registration outcomes.

  18. Effects of surface application of dolomitic limestone and calcium-magnesium silicate on soybean and maize in rotation with green manure in a tropical region

    Directory of Open Access Journals (Sweden)

    Gustavo Spadotti Amaral Castro

    2015-01-01

    Full Text Available Although lime is currently the material most frequently used to ameliorate soil acidity in Brazil, silicate could efficiently replace this source because of its greater solubility and its greater silicon content, which are beneficial for plant development. This study aimed to evaluate the effects of superficial lime and silicate application on soil chemical attributes as well as on soybean and maize nutrition and grain yields when these crops are grown in rotation with green manure. The experimental design was a complete randomized block with sixteen replicates. Plots were treated with one of two materials for acidity correction (dolomitic lime and calcium/magnesium silicate or with no soil correction, as a control. Silicate corrected soil acidity and increased exchangeable base levels in soil at greater depths faster than does liming. The application of both acidity-correcting materials increased N, Ca and Mg leaf concentrations, and all yield components and grain yield in soybean; but in maize, just silicate also increased N and Si when compared with lime, whereas both acidity-correcting increased just two yield components: grains per ear and mass of 100 grains, resulting in highest grain yield. The application of both acidity-correcting materials increased dry matter production of green manures, but for pigeon pea the silicate provided the best result in this dry-winter region.

  19. Neglected tropical diseases

    Directory of Open Access Journals (Sweden)

    David Molyneux

    2013-08-01

    Full Text Available Seventeen neglected tropical diseases (NTDs have been identified by the World Health Organization (WHO. It is estimated that over 1 billion people are infected with NTDs, with a further 1 billion at risk. The majority of NTDs occur in the tropics and sub-tropics and have particular characteristics in common.

  20. Quality maintenance Tropical Plants

    Directory of Open Access Journals (Sweden)

    Gláucia Moraes Dias

    2016-11-01

    Full Text Available The climatic characteristics of the country favor the cultivation of tropical flowers. The continued expansion of this market is due the beauty, exoticit nature and postharvest longevity of flower. However, little is known about the postharvest of tropical plants. Therefore, this paper provides information on harvest, handling and storage of cut tropical plantspostharvest, storage temperature, conditioning solution.

  1. Simple physical-empirical model of the precipitation distribution based on a tropical sea surface temperature threshold and the effects of climate change

    Science.gov (United States)

    Jauregui, Yakelyn R.; Takahashi, Ken

    2018-03-01

    The observed nonlinear relationship between tropical sea surface temperature (T_s) and precipitation ( P) on climate timescales, by which a threshold (T_c) must be exceeded by T_s in order for deep convection to occur, is the basis of a physical-empirical model (PEM) that we fitted to observational data and CMIP5 climate model output and used to show that, with essentially only two constant parameters (T_c and the sensitivity a_1 of P to T_s>T_c), it provides a useful first-order description of the climatological and interannual variability of the large-scale distribution of tropical P given T_s, as well as of the biases of the Global Climate Models (GCMs). A substantial limitation is its underestimation of the peak P in the convergence zones, as the necessary processes associated with the atmospheric circulation are not considered. The pattern of the intermodel correlation between the mean T_s-T_c for each GCM and the average P distribution is in agreement with the double ITCZ bias, featuring roughly zonally-symmetric off-equatorial maxima, rather than being regionally or hemispherically restricted. The inter-comparison of GCMs indicates a relationship between T_c with the near-equatorial low-level (850 hPa) tropospheric temperature, consistent with the interpretation that it is a measure of the convective inhibition (CIN). The underestimation of T_c is linked to the cold free tropospheric bias in the GCMs. However, the discrepancy among the observational datasets is a limitation for assessing the GCM biases from the PEM framework quantitatively. Under the RCP4.5 climate change scenario, T_c increases slightly more than the mean tropical T_s, implying a stabilizing trend consistent with the amplified free tropospheric warming relative to the surface. However, since a_1 increases by 10-50%/°C with the surface warming, its effect dominates and results in generally positive precipitation change (Δ P) in the equatorial regions. In the equatorial eastern

  2. Mercury net methylation in five tropical flood plain regions of Brazil: high in the root zone of floating macrophyte mats but low in surface sediments and flooded soils.

    Science.gov (United States)

    Guimarães, J R; Meili, M; Hylander, L D; de Castro e Silva, E; Roulet, M; Mauro, J B; de Lemos, R

    2000-10-16

    In aquatic systems, bottom sediments have often been considered as the main methylmercury (MeHg) production site. In tropical floodplain areas, however, floating meadows and flooded forests extend over large areas and can be important Hg methylating sites. We present here a cross-system comparison of the Hg net methylation capacity in surface sediments, flooded soils and roots of floating aquatic macrophytes, assayed by in situ incubation with 203Hg and extraction of formed Me203 Hg by acid leaching and toluene. The presence of mono-MeHg was confirmed by thin layer chromatography and other techniques. Study areas included floodplain lakes in the Amazon basin (Tapajós, Negro and Amazon rivers), the Pantanal floodplain (Paraguay river basin), freshwater coastal lagoons in Rio de Janeiro and oxbow lakes in the Mogi-Guaçú river, São Paulo state. Different Hg levels were added in assays performed in 1994-1998, but great care was taken to standardise all other test parameters, to allow data comparisons. Net MeHg production was one order of magnitude higher (mean 13.8%, range 0.28-35) in the living or decomposing roots of floating or rooted macrophyte mats (Eichhornia azurea, E. crassipes, Paspalum sp., Eleocharis sellowiana, Salvinia sp., S. rotundifolia and Scirpus cubensis) than in the surface layer of underlying lake sediments (mean 0.6%, range 0.022-2.5). Methylation in flooded soils presented a wide range and was in some cases similar to the one found in macrophyte roots but usually much lower. In a Tapajós floodplain lake, natural concentrations of MeHg in soil and sediment cores taken along a lake-forest transect agreed well with data on net methylation potentials in the same samples. E. azurea, E. crassipes and Salvinia presented the highest methylation potentials, up to 113 times higher than in sediments. Methylation in E. azurea from six lakes of the Paraguay and Cuiabá rivers, high Pantanal, was determined in the 1998 dry and wet seasons and ranged from

  3. Regional frameworks applied to hydrology: can landscape-based frameworks capture the hydrologic variability?

    Science.gov (United States)

    R. McManamay; D. Orth; C. Dolloff; E. Frimpong

    2011-01-01

    Regional frameworks have been used extensively in recent years to aid in broad-scale management. Widely used landscape-based regional frameworks, such as hydrologic landscape regions (HLRs) and physiographic provinces, may provide predictive tools of hydrologic variability. However, hydrologic-based regional frameworks, created using only streamflow data, are also...

  4. Self-organizing map network-based precipitation regionalization for the Tibetan Plateau and regional precipitation variability

    Science.gov (United States)

    Wang, Nini; Yin, Jianchuan

    2017-12-01

    A precipitation-based regionalization for the Tibetan Plateau (TP) was investigated for regional precipitation trend analysis and frequency analysis using data from 1113 grid points covering the period 1900-2014. The results utilizing self-organizing map (SOM) network suggest that four clusters of precipitation coherent zones can be identified, including the southwestern edge, the southern edge, the southeastern region, and the north central region. Regionalization results of the SOM network satisfactorily represent the influences of the atmospheric circulation systems such as the East Asian summer monsoon, the south Asian summer monsoon, and the mid-latitude westerlies. Regionalization results also well display the direct impacts of physical geographical features of the TP such as orography, topography, and land-sea distribution. Regional-scale annual precipitation trend as well as regional differences of annual and seasonal total precipitation were investigated by precipitation index such as precipitation concentration index (PCI) and Standardized Anomaly Index (SAI). Results demonstrate significant negative long-term linear trends in southeastern TP and the north central part of the TP, indicating arid and semi-arid regions in the TP are getting drier. The empirical mode decomposition (EMD) method shows an evolution of the main cycle with 4 and 12 months for all the representative grids of four sub-regions. The cross-wavelet analysis suggests that predominant and effective period of Indian Ocean Dipole (IOD) on monthly precipitation is around ˜12 months, except for the representative grid of the northwestern region.

  5. Quadrupole beam-based alignment in the RHIC interaction regions

    International Nuclear Information System (INIS)

    Ziegler, J.; Satogata, T.

    2011-01-01

    Continued beam-based alignment (BBA) efforts have provided significant benefit to both heavy ion and polarized proton operations at RHIC. Recent studies demonstrated previously unknown systematic beam position monitor (BPM) offset errors and produced accurate measurements of individual BPM offsets in the experiment interaction regions. Here we describe the algorithm used to collect and analyze data during the 2010 and early 2011 RHIC runs and the results of these measurements. BBA data has been collected over the past two runs for all three of the active experimental IRs at RHIC, updating results from the 2005 run which were taken with incorrectly installed offsets. The technique was successfully applied to expose a systematic misuse of the BPM survey offsets in the control system. This is likely to benefit polarized proton operations as polarization transmission through acceleration ramps depends on RMS orbit control in the arcs, but a quantitative understanding of its impact is still under active investigation. Data taking is ongoing as are refinements to the BBA technique aimed at reducing systematic errors and properly accounting for dispersive effects. Further development may focus on non-triplet BPMs such as those located near snakes, or arc quadrupoles that do not have individually shunted power supplies (a prerequisite for the current method) and as such, will require a modified procedure.

  6. Efficient classification of complete parameter regions based on semidefinite programming

    Directory of Open Access Journals (Sweden)

    Parrilo Pablo A

    2007-01-01

    Full Text Available Abstract Background Current approaches to parameter estimation are often inappropriate or inconvenient for the modelling of complex biological systems. For systems described by nonlinear equations, the conventional approach is to first numerically integrate the model, and then, in a second a posteriori step, check for consistency with experimental constraints. Hence, only single parameter sets can be considered at a time. Consequently, it is impossible to conclude that the "best" solution was identified or that no good solution exists, because parameter spaces typically cannot be explored in a reasonable amount of time. Results We introduce a novel approach based on semidefinite programming to directly identify consistent steady state concentrations for systems consisting of mass action kinetics, i.e., polynomial equations and inequality constraints. The duality properties of semidefinite programming allow to rigorously certify infeasibility for whole regions of parameter space, thus enabling the simultaneous multi-dimensional analysis of entire parameter sets. Conclusion Our algorithm reduces the computational effort of parameter estimation by several orders of magnitude, as illustrated through conceptual sample problems. Of particular relevance for systems biology, the approach can discriminate between structurally different candidate models by proving inconsistency with the available data.

  7. Data assimilation method based on the constraints of confidence region

    Science.gov (United States)

    Li, Yong; Li, Siming; Sheng, Yao; Wang, Luheng

    2018-03-01

    The ensemble Kalman filter (EnKF) is a distinguished data assimilation method that is widely used and studied in various fields including methodology and oceanography. However, due to the limited sample size or imprecise dynamics model, it is usually easy for the forecast error variance to be underestimated, which further leads to the phenomenon of filter divergence. Additionally, the assimilation results of the initial stage are poor if the initial condition settings differ greatly from the true initial state. To address these problems, the variance inflation procedure is usually adopted. In this paper, we propose a new method based on the constraints of a confidence region constructed by the observations, called EnCR, to estimate the inflation parameter of the forecast error variance of the EnKF method. In the new method, the state estimate is more robust to both the inaccurate forecast models and initial condition settings. The new method is compared with other adaptive data assimilation methods in the Lorenz-63 and Lorenz-96 models under various model parameter settings. The simulation results show that the new method performs better than the competing methods.

  8. Conceptual differences between the bioclimatic urbanism for Europe and for the tropical humid climate

    Energy Technology Data Exchange (ETDEWEB)

    Corbella, O.D.; Magalhaes, M.A.A.A. [Faculdade de Arquitetura e Urbanismo, Universidade Federal do Rio de Janeiro, Rio de Janeiro (Brazil)

    2008-05-15

    This article makes part of a series of conceptual papers to continue the discussion about how architecture and urbanism interact with climate, in tropical regions. Students engaged in normal courses of architecture in tropical regions, particularly in South America, develop their knowledge based on concepts generated in the developed countries - usually related to cold environments. Consequently, these students acquire wrong ideas about urban design of open spaces. Integrating urbanism and climate in tropical countries is still very incipient as an approach and many lecturers reject it, since they prefer to continue with a more formal one, dictated by most of the dominant countries. The herein paper underlines several different concepts and perspectives that separate the two conceptions, leading to a reflection about the subject. (author)

  9. An aftereffect of global warming on tropical Pacific decadal variability

    Science.gov (United States)

    Zheng, Jian; Liu, Qinyu; Wang, Chuanyang

    2018-03-01

    Studies have shown that global warming over the past six decades can weaken the tropical Pacific Walker circulation and maintain the positive phase of the Interdecadal Pacific Oscillation (IPO). Based on observations and model simulations, another aftereffect of global warming on IPO is found. After removing linear trends (global warming signals) from observations, however, the tropical Pacific climate still exhibited some obvious differences between two IPO negative phases. The boreal winter (DJF) equatorial central-eastern Pacific sea surface temperature (SST) was colder during the 1999-2014 period (P2) than that during 1961-1976 (P1). This difference may have been a result of global warming nonlinear modulation of precipitation; i.e., in the climatological rainy region, the core area of the tropical Indo-western Pacific warm pool receives more precipitation through the "wet-get-wetter" mechanism. Positive precipitation anomalies in the warm pool during P2 are much stronger than those during P1, even after subtracting the linear trend. Corresponding to the differences of precipitation, the Pacific Walker circulation is stronger in P2 than in P1. Consequent easterly winds over the equatorial Pacific led to a colder equatorial eastern-central Pacific during P2. Therefore, tropical Pacific climate differences between the two negative IPO phases are aftereffects of global warming. These aftereffects are supported by the results of coupled climate model experiments, with and without global warming.

  10. Phytogeography of the tropical north-east African mountains

    Directory of Open Access Journals (Sweden)

    I. Friis

    1983-11-01

    Full Text Available The tropical north-east African mountains are tentatively divided into four phytochoria, the formal rank of which is not defined. The division is based on patterns of distribution and endemism in the region. The recognition of a distinct Afromontane phytochorion is now well established (Chapman & White, 1970; Werger, 1978; White, 1978. However, there is still very little information on the phytogeography of the individual mountains or mountain systems. This study hopes to fill a little of the gap by analysing distribution patterns and patterns of endemism in the flora of the tropical north-east African mountains. The north-east African mountain system is the largest in tropical Africa (see e.g. map in White, 1978. At the core of this system is the large Ethiopian massif, around which are located various mountains and mountain chains. These include the Red Sea Hills in the Sudan, the mountain chain in northern Somalia, the south-west Arabian mountains, and the Imatong mountains of south-east Sudan. The latter are often referred to the East African mountain system (White, 1978 but. as I will point out later, they also have a close connection with the south-west highlands of Ethiopia. The paper presents some results of my study of the mountain flora of tropical north-east Africa, particularly the forest species. Where no source is indicated, the data are from my own unpublished studies.

  11. A modelling study of the event-based retention performance of green roof under the hot-humid tropical climate in Kuching.

    Science.gov (United States)

    Chai, C T; Putuhena, F J; Selaman, O S

    2017-12-01

    The influences of climate on the retention capability of green roof have been widely discussed in existing literature. However, knowledge on how the retention capability of green roof is affected by the tropical climate is limited. This paper highlights the retention performance of the green roof situated in Kuching under hot-humid tropical climatic conditions. Using the green roof water balance modelling approach, this study simulated the hourly runoff generated from a virtual green roof from November 2012 to October 2013 based on past meteorological data. The result showed that the overall retention performance was satisfactory with a mean retention rate of 72.5% from 380 analysed rainfall events but reduced to 12.0% only for the events that potentially trigger the occurrence of flash flood. By performing the Spearman rank's correlation analysis, it was found that the rainfall depth and mean rainfall intensity, individually, had a strong negative correlation with event retention rate, suggesting that the retention rate increases with decreased rainfall depth. The expected direct relationship between retention rate and antecedent dry weather period was found to be event size dependent.

  12. Growth-based Theories for Declining Regions? A Note on Conceptualisations of Demographic Change for Regional Economic Development

    Directory of Open Access Journals (Sweden)

    Anke Matuschewski

    2016-01-01

    Full Text Available This article aims to critically assess the economic growth paradigm, which typically underlies most approaches to regional policymaking for demographic change. While population losses, ageing and outmigration – i.e. phenomena that are addressed as demographic change – have become a matter of urgency for many European regions, most regional economic development theories remain silent about the population decline affecting the economic growth and development prospects of regions. Consequently, regional policies usually rely on the concept of economic growth, yet neglect the complexity and importance of demographic change and how it relates to the economic sphere. Due to this lack in nuance, we argue that regional policymaking fails to design adequate policy support for regions facing persistent demographic change and economic stagnation or decline as a result. Based on these observations, the paper examines a selection of regional economic development theories in search for alternative concepts of growth and development in the context of demographic change. To this aim, globalisation peripheries are introduced as a fruitful conceptual point of reference and, in combination with endogenous regional development theories, discussed as an alternative approach for regional policymaking.

  13. A Dooyeweerd-based approach to regional economic development

    NARCIS (Netherlands)

    Aay, H; Van Langevelde, A

    2005-01-01

    Within regional science there is a need for a general theory of regional economic development, one that evaluates and integrates existing approaches. In this paper, the philosophy of Herman Dooyeweerd is used as a basis for conceptualising the contours of such a theory. Contributions of this

  14. LivestockPlus — The sustainable intensification of forage-based agricultural systems to improve livelihoods and ecosystem services in the tropics

    Directory of Open Access Journals (Sweden)

    I. Rao

    2015-05-01

    Full Text Available As global demand for livestock products (such as meat, milk and eggs is expected to double by 2050, necessary increases to future production must be reconciled with negative environmental impacts that livestock cause. This paper describes the LivestockPlus concept and demonstrates how the sowing of improved forages can lead to the sustainable intensification of mixed crop-forage-livestock-tree systems in the tropics by producing multiple social, economic and environmental benefits. Sustainable intensification not only improves the productivity of tropical forage-based systems but also reduces the ecological footprint of livestock production and generates a diversity of ecosystem services (ES such as improved soil quality and reduced erosion, sedimentation and greenhouse gas (GHG emissions. Integrating improved grass and legume forages into mixed production systems (crop-livestock, tree-livestock, crop-tree-livestock can restore degraded lands and enhance system resilience to drought and waterlogging associated with climate change. When properly managed tropical forages accumulate large amounts of carbon in soil, fix atmospheric nitrogen (legumes, inhibit nitrification in soil and reduce nitrous oxide emissions (grasses, and reduce GHG emissions per unit livestock product. The LivestockPlus concept is defined as the sustainable intensification of forage-based systems, which is based on 3 interrelated intensification processes: genetic intensification - the development and use of superior grass and legume cultivars for increased livestock productivity; ecological intensification - the development and application of improved farm and natural resource management practices; and socio-economic intensification - the improvement of local and national institutions and policies, which enable refinements of technologies and support their enduring use. Increases in livestock productivity will require coordinated efforts to develop supportive government, non

  15. Tropical biomass burning smoke plume size, shape, reflectance, and age based on 2001–2009 MISR imagery of Borneo

    Directory of Open Access Journals (Sweden)

    C. S. Zender

    2012-04-01

    Full Text Available Land clearing for crops, plantations and grazing results in anthropogenic burning of tropical forests and peatlands in Indonesia, where images of fire-generated aerosol plumes have been captured by the Multi-angle Imaging SpectroRadiometer (MISR since 2001. Here we analyze the size, shape, optical properties, and age of distinct fire-generated plumes in Borneo from 2001–2009. The local MISR overpass at 10:30 a.m. misses the afternoon peak of Borneo fire emissions, and may preferentially sample longer plumes from persistent fires burning overnight. Typically the smoke flows with the prevailing southeasterly surface winds at 3–4 m s−1, and forms ovoid plumes whose mean length, height, and cross-plume width are 41 km, 708 m, and 27% of the plume length, respectively. 50% of these plumes have length between 24 and 50 km, height between 523 and 993 m and width between 18% and 30% of plume length. Length and cross-plume width are lognormally distributed, while height follows a normal distribution. Borneo smoke plume heights are similar to previously reported plume heights, yet Borneo plumes are on average nearly three times longer than previously studied plumes. This could be due to sampling or to more persistent fires and greater fuel loads in peatlands than in other tropical forests. Plume area (median 169 km2, with 25th and 75th percentiles at 99 km2 and 304 km2, respectively varies exponentially with length, though for most plumes a linear relation provides a good approximation. The MISR-estimated plume optical properties involve greater uncertainties than the geometric properties, and show patterns consistent with smoke aging. Optical depth increases by 15–25% in the down-plume direction, consistent with hygroscopic growth and nucleation overwhelming the effects of particle dispersion. Both particle single-scattering albedo and top-of-atmosphere reflectance peak about halfway down-plume, at

  16. Determining tropical cyclone inland flooding loss on a large scale through a new flood peak ratio-based methodology

    International Nuclear Information System (INIS)

    Czajkowski, Jeffrey; Michel-Kerjan, Erwann; Villarini, Gabriele; Smith, James A

    2013-01-01

    In recent years, the United States has been severely affected by numerous tropical cyclones (TCs) which have caused massive damages. While media attention mainly focuses on coastal losses from storm surge, these TCs have inflicted significant devastation inland as well. Yet, little is known about the relationship between TC-related inland flooding and economic losses. Here we introduce a novel methodology that first successfully characterizes the spatial extent of inland flooding, and then quantifies its relationship with flood insurance claims. Hurricane Ivan in 2004 is used as illustration. We empirically demonstrate in a number of ways that our quantified inland flood magnitude produces a very good representation of the number of inland flood insurance claims experienced. These results highlight the new technological capabilities that can lead to a better risk assessment of inland TC flood. This new capacity will be of tremendous value to a number of public and private sector stakeholders dealing with disaster preparedness. (letter)

  17. Morphotype-based characterization of arbuscular mycorrhizal fungal communities in a restored tropical dry forest, Margarita island-Venezuela

    Directory of Open Access Journals (Sweden)

    Laurie Fajardo

    2015-09-01

    Full Text Available The mycorrhizal component of revegetated areas after ecological restoration or rehabilitation in arid and semiarid tropical areas has been scarcely assessed, particularly those made after mining disturbance. We evaluated and compared the presence of arbuscular mycorrhizal fungi of a small area of restored tropical dry for est destroyed by sand extraction, with a non-restored area of similar age, at the peninsula of Macanao, Margarita Island (Venezuela. Our study was undertaken in 2009, four years after planting, and the mycorrhizal status was evaluated in four restored plots (8 x 12.5 m (two were previously treated with hydrogel (R2 and R2', and two were left untreated (R1 and R1', and four non-restored plots of similar size (NR1 and NR1' with graminoid physiognomy with some scattered shrubs; and NR2 and NR2', with a more species rich plant community. Apparently the restoration management promoted higher arbuscular mycorrhizal fungi (AMF species richness and diversity, particularly in restored soils where the hydrogel was added (R2 treatment. Soil of the NR1 treat ment (with a higher herbaceous component showed the highest spore density, compared to samples of soils under the other treatments. Considering species composition, Claroideoglomus etunicatumand Rhizophagus intraradiceswere found in all treatments; besides, Diversispora spurcaand Funneliformis geosporumwere only found in non-restored plots, while members of the Gigasporaceae (a family associated with little disturbed sites were commonly observed in the plots with restored soils. Mycorrhizal colonization was similar in the restored and non-restored areas, being a less sensitive indicator of the ecosystem recovery. The trend of higher richness and diversity of AMF in the restored plot with hydrogel suggests that this management strategy contributes to accelerate the natural regeneration in those ecosystems where water plays an essential role.

  18. Region based route planning - Multi-abstraction route planning based on intermediate level vision processing

    Science.gov (United States)

    Doshi, Rajkumar S.; Lam, Raymond; White, James E.

    1989-01-01

    Intermediate and high level processing operations are performed on vision data for the organization of images into more meaningful, higher-level topological representations by means of a region-based route planner (RBRP). The RBRP operates in terrain scenarios where some or most of the terrain is occluded, proceeding without a priori maps on the basis of two-dimensional representations and gradient-and-roughness information. Route planning is accomplished by three successive abstractions and yields a detailed point-by-point path by searching only within the boundaries of relatively small regions.

  19. A MODIS-Based Energy Balance to Estimate Evapotranspiration for Clear-Sky Days in Brazilian Tropical Savannas

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    Yadvinder S. Malhi

    2012-03-01

    Full Text Available Evapotranspiration (ET plays an important role in global climate dynamics and in primary production of terrestrial ecosystems; it represents the mass and energy transfer from the land to atmosphere. Limitations to measuring ET at large scales using ground-based methods have motivated the development of satellite remote sensing techniques. The purpose of this work is to evaluate the accuracy of the SEBAL algorithm for estimating surface turbulent heat fluxes at regional scale, using 28 images from MODIS. SEBAL estimates are compared with eddy-covariance (EC measurements and results from the hydrological model MGB-IPH. SEBAL instantaneous estimates of latent heat flux (LE yielded r 2= 0.64 and r2 = 0.62 over sugarcane croplands and savannas when compared against in situ EC estimates. At the same sites, daily aggregated estimates of LE were r 2 = 0.76 and r2 = 0.66, respectively. Energy balance closure showed that turbulent fluxes over sugarcane croplands were underestimated by 7% and 9% over savannas. Average daily ET from SEBAL is in close agreement with estimates from the hydrological model for an overlay of 38,100 km2 (r2 = 0.88. Inputs to which the algorithm is most sensitive are vegetation index (NDVI, gradient of temperature (dT to compute sensible heat flux (H and net radiation (Rn. It was verified that SEBAL has a tendency to overestimate results both at local and regional scales probably because of low sensitivity to soil moisture and water stress. Nevertheless the results confirm the potential of the SEBAL algorithm, when used with MODIS images for estimating instantaneous LE and daily ET from large areas.

  20. Ensemble-based Regional Climate Prediction: Political Impacts

    Science.gov (United States)

    Miguel, E.; Dykema, J.; Satyanath, S.; Anderson, J. G.

    2008-12-01

    Accurate forecasts of regional climate, including temperature and precipitation, have significant implications for human activities, not just economically but socially. Sub Saharan Africa is a region that has displayed an exceptional propensity for devastating civil wars. Recent research in political economy has revealed a strong statistical relationship between year to year fluctuations in precipitation and civil conflict in this region in the 1980s and 1990s. To investigate how climate change may modify the regional risk of civil conflict in the future requires a probabilistic regional forecast that explicitly accounts for the community's uncertainty in the evolution of rainfall under anthropogenic forcing. We approach the regional climate prediction aspect of this question through the application of a recently demonstrated method called generalized scalar prediction (Leroy et al. 2009), which predicts arbitrary scalar quantities of the climate system. This prediction method can predict change in any variable or linear combination of variables of the climate system averaged over a wide range spatial scales, from regional to hemispheric to global. Generalized scalar prediction utilizes an ensemble of model predictions to represent the community's uncertainty range in climate modeling in combination with a timeseries of any type of observational data that exhibits sensitivity to the scalar of interest. It is not necessary to prioritize models in deriving with the final prediction. We present the results of the application of generalized scalar prediction for regional forecasts of temperature and precipitation and Sub Saharan Africa. We utilize the climate predictions along with the established statistical relationship between year-to-year rainfall variability in Sub Saharan Africa to investigate the potential impact of climate change on civil conflict within that region.

  1. Involvement of both the V2 and V3 Regions of the CCR5-Tropic Human Immunodeficiency Virus Type 1 Envelope in Reduced Sensitivity to Macrophage Inflammatory Protein 1α

    Science.gov (United States)

    Maeda, Yosuke; Foda, Mohamed; Matsushita, Shuzo; Harada, Shinji

    2000-01-01

    To determine whether C-C chemokines play an important role in the phenotype switch of human immunodeficiency virus (HIV) from CCR5 to CXCR4 usage during the course of an infection in vivo, macrophage inflammatory protein (MIP)-1α-resistant variants were isolated from CCR5-tropic (R5) HIV-1 in vitro. The selected variants displayed reduced sensitivities to MIP-1α (fourfold) through CCR5-expressing CD4-HeLa/long terminal repeat–β-galactosidase (MAGI/CCR5) cells. The variants were also resistant to other natural ligands for CCR5, namely, MIP-1β (>4-fold) and RANTES (regulated upon activation, normal T-cell expressed and secreted) (6-fold). The env sequence analyses revealed that the variants had amino acid substitutions in V2 (valine 166 to methionine) and V3 (serine 303 to glycine), although the same V3 substitution appeared in virus passaged without MIP-1α. A single-round replication assay using a luciferase reporter HIV-1 strain pseudotyped with mutant envelopes confirmed that mutations in both V2 and V3 were necessary to confer the reduced sensitivity to MIP-1α, MIP-1β, and RANTES. However, the double mutant did not switch its chemokine receptor usage from CCR5 to CXCR4, indicating the altered recognition of CCR5 by this mutant. These results indicated that V2 combined with the V3 region of the CCR5-tropic HIV-1 envelope modulates the sensitivity of HIV-1 to C-C chemokines without altering the ability to use chemokine receptors. PMID:10644351

  2. Risk management in crop production based on the regional index

    Directory of Open Access Journals (Sweden)

    Kokot Željko

    2017-01-01

    Full Text Available Regional index insurance is one of the newer instruments for reducing losses in crop production. The regional index indicates the average yield or average production value in a region, representing the basis for the premium calculation and insurance benefits. The main advantage of this insurance model is that it does not require the damage assessment, which is one of major problems in the relationship between the insured and insurer. In the case of corn, wheat and sunflower production as the most important crops in the region of Ada municipality, the authors describe the methodology of application of the analysed insurance system. Implementation of this contemporary form of insurance in Serbia would reduce the negative financial consequences in agricultural production. The abovementioned model of insurance can be seen as a significant alternative to conventional insurance, which can increase insured area and number of insured, and trust and confidence in insurance companies would also be restored.

  3. Inflated Uncertainty in Multimodel-Based Regional Climate Projections

    Science.gov (United States)

    Madsen, Marianne Sloth; Langen, Peter L.; Boberg, Fredrik; Christensen, Jens Hesselbjerg

    2017-11-01

    Multimodel ensembles are widely analyzed to estimate the range of future regional climate change projections. For an ensemble of climate models, the result is often portrayed by showing maps of the geographical distribution of the multimodel mean results and associated uncertainties represented by model spread at the grid point scale. Here we use a set of CMIP5 models to show that presenting statistics this way results in an overestimation of the projected range leading to physically implausible patterns of change on global but also on regional scales. We point out that similar inconsistencies occur in impact analyses relying on multimodel information extracted using statistics at the regional scale, for example, when a subset of CMIP models is selected to represent regional model spread. Consequently, the risk of unwanted impacts may be overestimated at larger scales as climate change impacts will never be realized as the worst (or best) case everywhere.

  4. A REGION-BASED MULTI-SCALE APPROACH FOR OBJECT-BASED IMAGE ANALYSIS

    Directory of Open Access Journals (Sweden)

    T. Kavzoglu

    2016-06-01

    Full Text Available Within the last two decades, object-based image analysis (OBIA considering objects (i.e. groups of pixels instead of pixels has gained popularity and attracted increasing interest. The most important stage of the OBIA is image segmentation that groups spectrally similar adjacent pixels considering not only the spectral features but also spatial and textural features. Although there are several parameters (scale, shape, compactness and band weights to be set by the analyst, scale parameter stands out the most important parameter in segmentation process. Estimating optimal scale parameter is crucially important to increase the classification accuracy that depends on image resolution, image object size and characteristics of the study area. In this study, two scale-selection strategies were implemented in the image segmentation process using pan-sharped Qickbird-2 image. The first strategy estimates optimal scale parameters for the eight sub-regions. For this purpose, the local variance/rate of change (LV-RoC graphs produced by the ESP-2 tool were analysed to determine fine, moderate and coarse scales for each region. In the second strategy, the image was segmented using the three candidate scale values (fine, moderate, coarse determined from the LV-RoC graph calculated for whole image. The nearest neighbour classifier was applied in all segmentation experiments and equal number of pixels was randomly selected to calculate accuracy metrics (overall accuracy and kappa coefficient. Comparison of region-based and image-based segmentation was carried out on the classified images and found that region-based multi-scale OBIA produced significantly more accurate results than image-based single-scale OBIA. The difference in classification accuracy reached to 10% in terms of overall accuracy.

  5. SYMMETRIC DETERMINATION OF THE SEVERITY OF PRODUCTIVITY CONSTRAINTS OF FISH FARMERS IN THE TROPICS: A CASE STUDY OF THE NIGER DELTA REGION, NIGERIA

    Directory of Open Access Journals (Sweden)

    VALERIE Solomon

    2001-09-01

    Full Text Available The study was conducted to fi ll the gap in the dearth of information on systematic approach to ascertain the severity as well as the magnitude of the constraints responsible for the sub-optimal operation of fi sh farming in Nigeria. 120 randomly selected fish farmers from a list of 186 fi sh farmers in the state were interviewed. Participatory appraisal technique and econometric technique were adopted to ascertain the most severe major constraints and also the severity index of each of the sub-constraints that are responsible for the sub-optimal aquaculture operation in the Niger Delta region of Nigeria and the cause of withdrawal from aquaculture by some fi sh farmers. The sub-constraints severity within the major constraints, across the region gave more insight into the causes of the high rate of withdrawals from aquaculture and the decline in aquaculture productivity in the region. How productive the regional aquaculture would be, even in the nearest future, would depend to a large extent on these major factors: production, marketing and advancement in related technology. Unless pragmatic approach is used to reduce the constraints responsible for the high rate of withdrawal, fi sh food security in the Niger Delta Region of Nigeria would still be elusive.

  6. DWT-SATS Based Detection of Image Region Cloning

    OpenAIRE

    Michael Zimba

    2014-01-01

    A duplicated image region may be subjected to a number of attacks such as noise addition, compression, reflection, rotation, and scaling with the intention of either merely mating it to its targeted neighborhood or preventing its detection. In this paper, we present an effective and robust method of detecting duplicated regions inclusive of those affected by the various attacks. In order to reduce the dimension of the image, the proposed algorithm firstly performs discrete wavelet transform, ...

  7. Small changes in climate can profoundly alter the dynamics and ecosystem services of tropical crater lakes.

    Directory of Open Access Journals (Sweden)

    Émilie Saulnier-Talbot

    Full Text Available African tropical lakes provide vital ecosystem services including food and water to some of the fastest growing human populations, yet they are among the most understudied ecosystems in the world. The consequences of climate change and other stressors on the tropical lakes of Africa have been informed by long-term analyses, but these studies have largely focused on the massive Great Rift Valley lakes. Our objective was to evaluate how recent climate change has altered the functioning and services of smaller tropical lakes, which are far more abundant on the landscape. Based on a paired analysis of 20 years of high-resolution water column data and a paleolimnological record from a small crater lake in western Uganda, we present evidence that even a modest warming of the air (∼0.9°C increase over 20 years and changes in the timing and intensity of rainfall can have significant consequences on the dynamics of this common tropical lake type. For example, we observed a significant nonlinear increase (R(2 adj  = 0.23, e.d.f. = 7, p<0.0001 in thermal stability over the past 20 years. This resulted in the expansion of anoxic waters and consequent deterioration of fish habitat and appears to have abated primary production; processes that may impair ecosystem services for a vulnerable human population. This study on a system representative of small tropical crater lakes highlights the far-reaching effects of global climatic change on tropical waters. Increased research efforts into tropical aquatic ecosystem health and the development of sound management practices are necessary in order to strengthen adaptive capabilities in tropical regions.

  8. Small changes in climate can profoundly alter the dynamics and ecosystem services of tropical crater lakes.

    Science.gov (United States)

    Saulnier-Talbot, Émilie; Gregory-Eaves, Irene; Simpson, Kyle G; Efitre, Jackson; Nowlan, Tobias E; Taranu, Zofia E; Chapman, Lauren J

    2014-01-01

    African tropical lakes provide vital ecosystem services including food and water to some of the fastest growing human populations, yet they are among the most understudied ecosystems in the world. The consequences of climate change and other stressors on the tropical lakes of Africa have been informed by long-term analyses, but these studies have largely focused on the massive Great Rift Valley lakes. Our objective was to evaluate how recent climate change has altered the functioning and services of smaller tropical lakes, which are far more abundant on the landscape. Based on a paired analysis of 20 years of high-resolution water column data and a paleolimnological record from a small crater lake in western Uganda, we present evidence that even a modest warming of the air (∼0.9°C increase over 20 years) and changes in the timing and intensity of rainfall can have significant consequences on the dynamics of this common tropical lake type. For example, we observed a significant nonlinear increase (R(2) adj  = 0.23, e.d.f. = 7, pdeterioration of fish habitat and appears to have abated primary production; processes that may impair ecosystem services for a vulnerable human population. This study on a system representative of small tropical crater lakes highlights the far-reaching effects of global climatic change on tropical waters. Increased research efforts into tropical aquatic ecosystem health and the development of sound management practices are necessary in order to strengthen adaptive capabilities in tropical regions.

  9. Ocean barrier layers' effect on tropical cyclone intensification.

    Science.gov (United States)

    Balaguru, Karthik; Chang, Ping; Saravanan, R; Leung, L Ruby; Xu, Zhao; Li, Mingkui; Hsieh, Jen-Shan

    2012-09-04

    Improving a tropical cyclone's forecast and mitigating its destructive potential requires knowledge of various environmental factors that influence the cyclone's path and intensity. Herein, using a combination of observations and model simulations, we systematically demonstrate that tropical cyclone intensification is significantly affected by salinity-induced barrier layers, which are "quasi-permanent" features in the upper tropical oceans. When tropical cyclones pass over regions with barrier layers, the increased stratification and stability within the layer reduce storm-induced vertical mixing and sea surface temperature cooling. This causes an increase in enthalpy flux from the ocean to the atmosphere and, consequently, an intensification of tropical cyclones. On average, the tropical cyclone intensification rate is nearly 50% higher over regions with barrier layers, compared to regions without. Our finding, which underscores the importance of observing not only the upper-ocean thermal structure but also the salinity structure in deep tropical barrier layer regions, may be a key to more skillful predictions of tropical cyclone intensities through improved ocean state estimates and simulations of barrier layer processes. As the hydrological cycle responds to global warming, any associated changes in the barrier layer distribution must be considered in projecting future tropical cyclone activity.

  10. The global burden of snakebite: a literature analysis and modelling based on regional estimates of envenoming and deaths.

    Directory of Open Access Journals (Sweden)

    Anuradhani Kasturiratne

    2008-11-01

    Full Text Available BACKGROUND: Envenoming resulting from snakebites is an important public health problem in many tropical and subtropical countries. Few attempts have been made to quantify the burden, and recent estimates all suffer from the lack of an objective and reproducible methodology. In an attempt to provide an accurate, up-to-date estimate of the scale of the global problem, we developed a new method to estimate the disease burden due to snakebites. METHODS AND FINDINGS: The global estimates were based on regional estimates that were, in turn, derived from data available for countries within a defined region. Three main strategies were used to obtain primary data: electronic searching for publications on snakebite, extraction of relevant country-specific mortality data from databases maintained by United Nations organizations, and identification of grey literature by discussion with key informants. Countries were grouped into 21 distinct geographic regions that are as epidemiologically homogenous as possible, in line with the Global Burden of Disease 2005 study (Global Burden Project of the World Bank. Incidence rates for envenoming were extracted from publications and used to estimate the number of envenomings for individual countries; if no data were available for a particular country, the lowest incidence rate within a neighbouring country was used. Where death registration data were reliable, reported deaths from snakebite were used; in other countries, deaths were estimated on the basis of observed mortality rates and the at-risk population. We estimate that, globally, at least 421,000 envenomings and 20,000 deaths occur each year due to snakebite. These figures may be as high as 1,841,000 envenomings and 94,000 deaths. Based on the fact that envenoming occurs in about one in every four snakebites, between 1.2 million and 5.5 million snakebites could occur annually. CONCLUSIONS: Snakebites cause considerable morbidity and mortality worldwide. The

  11. The Challenge of Forecasting Metropolitan Growth: Urban Characteristics Based Models versus Regional Dummy Based Models

    OpenAIRE

    NA

    2005-01-01

    This paper presents a study of errors in forecasting the population of Metropolitan Statistical Areas and the Primary MSAs of Consolidated Metropolitan Statistical Areas and New England MAs. The forecasts are for the year 2000 and are based on a semi-structural model estimated by Mills and Lubelle using 1970 to 1990 census data on population, employment and relative real wages. This model allows the testing of regional effects on population and employment growth. The year 2000 forecasts are f...

  12. Security region-based small signal stability analysis of power systems with FSIG based wind farm

    Science.gov (United States)

    Qin, Chao; Zeng, Yuan; Yang, Yang; Cui, Xiaodan; Xu, Xialing; Li, Yong

    2018-02-01

    Based on the Security Region approach, the impact of fixed-speed induction generator based wind farm on the small signal stability of power systems is analyzed. Firstly, the key factors of wind farm on the small signal stability of power systems are analyzed and the parameter space for small signal stability region is formed. Secondly, the small signal stability region of power systems with wind power is established. Thirdly, the corresponding relation between the boundary of SSSR and the dominant oscillation mode is further studied. Results show that the integration of fixed-speed induction generator based wind farm will cause the low frequency oscillation stability of the power system deteriorate. When the output of wind power is high, the oscillation stability of the power system is mainly concerned with the inter-area oscillation mode caused by the integration of the wind farm. Both the active power output and the capacity of reactive power compensation of the wind farm have a significant influence on the SSSR. To improve the oscillation stability of power systems with wind power, it is suggested to reasonably set the reactive power compensation capacity for the wind farm through SSSR.

  13. Applications of NASA TROPICS Data for Tropical Cyclone Analysis, Nowcasting, and Impacts

    Science.gov (United States)

    Zavodsky, B.; Dunion, J. P.; Blackwell, W. J.; Braun, S. A.; Green, D. S.; Velden, C.; Adler, R. F.; Cossuth, J.; Murray, J. J.; Brennan, M. J.

    2017-12-01

    The National Aeronautics and Space Administration (NASA) Time-Resolved Observations of Precipitation structure and storm Intensity with a Constellation of Smallsats (TROPICS) mission is a constellation of state-of-the-science observing platforms that will measure temperature and humidity soundings and precipitation with spatial resolution comparable to current operational passive microwave sounders but with unprecedented temporal resolution. TROPICS is a cost-capped ($30M) Venture-class mission funded by the NASA Earth Science Division. The mission is comprised of a constellation of 3 unit (3U) SmallSats, each hosting a 12-channel passive microwave spectrometer based on the Micro-sized Microwave Atmospheric Satellite 2 (MicroMAS-2) developed at MIT LL. TROPICS will provide imagery near 91 and 205 GHz, temperature sounding near 118 GHz, and moisture sounding near 183 GHz. Spatial resolution at nadir will be around 27 km for temperature and 17 km for moisture and precipitation. The swath width is approximately 2000 km. TROPICS enables temporal resolution similar to geostationary orbit but at a much lower cost, demonstrating a technology that could impact the design of future Earth-observing missions. The TROPICS satellites for the mission are slated for delivery to NASA in 2019 with potential launch opportunities in 2020. The primary mission objective of TROPICS is to relate temperature, humidity, and precipitation structure to the evolution of tropical cyclone (TC) intensity. This abstract summarizes the outcomes of the 1st TROPICS Applications Workshop, held from May 8-10, 2017 at the University of Miami. At this meeting, a series of presentations and breakout discussions in the topical areas of Tropical Cyclone Dynamics, Tropical Cyclone Analysis and Nowcasting, Tropical Cyclone Modeling and Data Assimilation, and Terrestrial Impacts were convened to identify applications of the mission data and to begin to establish a community of end-users who will be able to

  14. The decision of farmers from the tropical region of Cochabamba in Bolivia to cultivate coca instead of state-recommended alternative products

    Directory of Open Access Journals (Sweden)

    Barrientos Juan Carlos

    2006-06-01

    Hidden="false" UnhideWhenUsed="false" QFormat="true" Name="Intense Emphasis" />

    Despite national coca cultivation having been prohibited from 1973 onwards and the rapid reduction of coca plantations up to 2000, coca is still being cultivated in the tropical region of  Cochabamba. Technical and economic aspects are responsible for many farmers deciding to continue to cultivate coca and not to cultivate alternative crops. Coca cultivation

  15. Comparison of total column ozone obtained by the IASI-MetOp satellite with ground-based and OMI satellite observations in the southern tropics and subtropics

    Directory of Open Access Journals (Sweden)

    A. M. Toihir

    2015-09-01

    Full Text Available This paper presents comparison results of the total column ozone (TCO data product over 13 southern tropical and subtropical sites recorded from the Infrared Atmospheric Sounder Interferometer (IASI onboard the EUMETSAT (European organization for the exploitation of METeorological SATellite MetOp (Meteorological Operational satellite program satellite. TCO monthly averages obtained from IASI between June 2008 and December 2012 are compared with collocated TCO measurements from the Ozone Monitoring Instrument (OMI on the OMI/Aura satellite and the Dobson and SAOZ (Système d'Analyse par Observation Zénithale ground-based instruments. The results show that IASI displays a positive bias with an average less than 2 % with respect to OMI and Dobson observations, but exhibits a negative bias compared to SAOZ over Bauru with a bias around 2.63 %. There is a good agreement between IASI and the other instruments, especially from 15° S southward where a correlation coefficient higher than 0.87 is found. IASI exhibits a seasonal dependence, with an upward trend in autumn and a downward trend during spring, especially before September 2010. After September 2010, the autumn seasonal bias is considerably reduced due to changes made to the retrieval algorithm of the IASI level 2 (L2 product. The L2 product released after August (L2 O3 version 5 (v5 matches TCO from the other instruments better compared to version 4 (v4, which was released between June 2008 and August 2010. IASI bias error recorded from September 2010 is estimated to be at 1.5 % with respect to OMI and less than ±1 % with respect to the other ground-based instruments. Thus, the improvement made by O3 L2 version 5 (v5 product compared with version 4 (v4, allows IASI TCO products to be used with confidence to study the distribution and interannual variability of total ozone in the southern tropics and subtropics.

  16. On the Characterization of Rainfall Associated with U.S. Landfalling North Atlantic Tropical Cyclones Based on Satellite Data and Numerical Weather Prediction Outputs

    Science.gov (United States)

    Luitel, B. N.; Villarini, G.; Vecchi, G. A.

    2014-12-01

    When we talk about tropical cyclones (TCs), the first things that come to mind are strong winds and storm surge affecting the coastal areas. However, according to the Federal Emergency Management Agency (FEMA) 59% of the deaths caused by TCs since 1970 is due to fresh water flooding. Heavy rainfall associated with TCs accounts for 13% of heavy rainfall events nationwide for the June-October months, with this percentage being much higher if the focus is on the eastern and southern United States. This study focuses on the evaluation of precipitation associated with the North Atlantic TCs that affected the continental United States over the period 2007 - 2012. We evaluate the rainfall associated with these TCs using four satellite based rainfall products: Tropical Rainfall Measuring Mission - Multi-satellite Precipitation Analysis (TMPA; both real-time and research version); Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN); Climate Prediction Center (CPC) MORPHing technique (CMORPH). As a reference data we use gridded rainfall provided by CPC (Daily US Unified Gauge-Based Analysis of Precipitation). Rainfall fields from each of these satellite products are compared to the reference data, providing valuable information about the realism of these products in reproducing the rainfall associated with TCs affecting the continental United States. In addition to the satellite products, we evaluate the forecasted rainfall produced by five state-of-the-art numerical weather prediction (NWP) models: European Centre for Medium-Range Weather Forecasts (ECMWF), UK Met Office (UKMO), National Centers for Environmental Prediction (NCEP), China Meteorological Administration (CMA), and Canadian Meteorological Center (CMC). The skill of these models in reproducing TC rainfall is quantified for different lead times, and discussed in light of the performance of the satellite products.

  17. Complex Networks Dynamics Based on Events-Phase Synchronization and Intensity Correlation Applied to The Anomaly Patterns and Extremes in The Tropical African Climate System

    Science.gov (United States)

    Oluoch, K.; Marwan, N.; Trauth, M.; Loew, A.; Kurths, J.

    2012-04-01

    The African continent lie almost entirely within the tropics and as such its (tropical) climate systems are predominantly governed by the heterogeneous, spatial and temporal variability of the Hadley and Walker circulations. The variabilities in these meridional and zonal circulations lead to intensification or suppression of the intensities, durations and frequencies of the Inter-tropical Convergence Zone (ICTZ) migration, trade winds and subtropical high-pressure regions and the continental monsoons. The above features play a central role in determining the African rainfall spatial and temporal variability patterns. The current understanding of these climate features and their influence on the rainfall patterns is not sufficiently understood. Like many real-world systems, atmospheric-oceanic processes exhibit non-linear properties that can be better explored using non-linear (NL) methods of time-series analysis. Over the recent years, the complex network approach has evolved as a powerful new player in understanding spatio-temporal dynamics and evolution of complex systems. Together with NL techniques, it is continuing to find new applications in many areas of science and technology including climate research. We would like to use these two powerful methods to understand the spatial structure and dynamics of African rainfall anomaly patterns and extremes. The method of event synchronization (ES) developed by Quiroga et al., 2002 and first applied to climate networks by Malik et al., 2011 looks at correlations with a dynamic time lag and as such, it is a more intuitive way to correlate a complex and heterogeneous system like climate networks than a fixed time delay most commonly used. On the other hand, the short comings of ES is its lack of vigorous test statistics for the significance level of the correlations, and the fact that only the events' time indices are synchronized while all information about how the relative intensities propagate within network

  18. Pan-tropical monitoring of deforestation

    International Nuclear Information System (INIS)

    Achard, F; DeFries, R; Eva, H; Hansen, M; Mayaux, P; Stibig, H-J

    2007-01-01

    This paper reviews the technical capabilities for monitoring deforestation from a pan-tropical perspective in response to the United Nations Framework Convention on Climate Change (UNFCCC) process, which is studying the technical issues surrounding the ability to reduce greenhouse gas emissions from deforestation in developing countries. The successful implementation of such policies requires effective forest monitoring systems that are reproducible, provide consistent results, meet standards for mapping accuracy, and can be implemented from national to pan-tropical levels. Remotely sensed data, supported by ground observations, are crucial to such efforts. Recent developments in global to regional monitoring of forests can contribute to reducing the uncertainties in estimates of emissions from deforestation. Monitoring systems at national levels in developing countries can also benefit from pan-tropical and regional observations, mainly by identifying hot spots of change and prioritizing areas for monitoring at finer spatial scales. A pan-tropical perspective is also required to ensure consistency between different national monitoring systems. Data sources already exist to determine baseline periods in the 1990s as historical reference points. Key requirements for implementing such monitoring programs, both at pan-tropical and at national scales, are international commitment of resources to increase capacity, coordination of observations to ensure pan-tropical coverage, access to free or low-cost data, and standardized, consensus protocols for data interpretation and analysis

  19. Testing the ecotoxicology of vegetable versus mineral based lubricating oils: 1. Degradation rates using tropical marine microbes

    International Nuclear Information System (INIS)

    Mercurio, Philip; Burns, Kathryn A.; Negri, Andrew

    2004-01-01

    Vegetable-derived lubricants (VDL) might be more biodegradable than mineral-derived lubricants (MDL) due to the absence of high molecular weight aromatics, but this remains largely untested in tropical conditions. In this laboratory study, the degradation rates of 2-stroke, 4-stroke and hydraulic VDLs were compared with their MDL counterparts in the presence of mangrove and coral reef microbial communities. While MDLs were comprised largely of unresolved saturated and some aromatic hydrocarbons, their VDL counterparts contained, potentially more degradable, fatty acid methyl esters. Degradation of some VDL was observed by day 7, with the 2-stroke VDL markedly consumed by mangrove microorganisms and the hydraulic VDL degraded by both microorganism communities after this short period. All of the VDL groups were significantly more degraded than the comparable MDLs mineral oil lubricants over 14 days in the presence of either mangrove or coral reef microbial communities. In general the mangrove-sourced microorganisms more efficiently degraded the lubricants than reef-sourced microorganisms. - Vegetable-derived lubricants were more degradable than mineral oil lubricants

  20. Testing the ecotoxicology of vegetable versus mineral based lubricating oils: 1. Degradation rates using tropical marine microbes.

    Science.gov (United States)

    Mercurio, Philip; Burns, Kathryn A; Negri, Andrew

    2004-05-01

    Vegetable-derived lubricants (VDL) might be more biodegradable than mineral-derived lubricants (MDL) due to the absence of high molecular weight aromatics, but this remains largely untested in tropical conditions. In this laboratory study, the degradation rates of 2-stroke, 4-stroke and hydraulic VDLs were compared with their MDL counterparts in the presence of mangrove and coral reef microbial communities. While MDLs were comprised largely of unresolved saturated and some aromatic hydrocarbons, their VDL counterparts contained, potentially more degradable, fatty acid methyl esters. Degradation of some VDL was observed by day 7, with the 2-stroke VDL markedly consumed by mangrove microorganisms and the hydraulic VDL degraded by both microorganism communities after this short period. All of the VDL groups were significantly more degraded than the comparable MDLs mineral oil lubricants over 14 days in the presence of either mangrove or coral reef microbial communities. In general the mangrove-sourced microorganisms more efficiently degraded the lubricants than reef-sourced microorganisms.

  1. Testing the ecotoxicology of vegetable versus mineral based lubricating oils: 1. Degradation rates using tropical marine microbes

    Energy Technology Data Exchange (ETDEWEB)

    Mercurio, Philip; Burns, Kathryn A.; Negri, Andrew

    2004-05-01

    Vegetable-derived lubricants (VDL) might be more biodegradable than mineral-derived lubricants (MDL) due to the absence of high molecular weight aromatics, but this remains largely untested in tropical conditions. In this laboratory study, the degradation rates of 2-stroke, 4-stroke and hydraulic VDLs were compared with their MDL counterparts in the presence of mangrove and coral reef microbial communities. While MDLs were comprised largely of unresolved saturated and some aromatic hydrocarbons, their VDL counterparts contained, potentially more degradable, fatty acid methyl esters. Degradation of some VDL was observed by day 7, with the 2-stroke VDL markedly consumed by mangrove microorganisms and the hydraulic VDL degraded by both microorganism communities after this short period. All of the VDL groups were significantly more degraded than the comparable MDLs mineral oil lubricants over 14 days in the presence of either mangrove or coral reef microbial communities. In general the mangrove-sourced microorganisms more efficiently degraded the lubricants than reef-sourced microorganisms. - Vegetable-derived lubricants were more degradable than mineral oil lubricants.

  2. Genomic analyses of tropical beef cattle fertility based on genotyping pools of Brahman cows with unknown pedigree.

    Science.gov (United States)

    Reverter, A; Porto-Neto, L R; Fortes, M R S; McCulloch, R; Lyons, R E; Moore, S; Nicol, D; Henshall, J; Lehnert, S A

    2016-10-01

    We introduce an innovative approach to lowering the overall cost of obtaining genomic EBV (GEBV) and encourage their use in commercial extensive herds of Brahman beef cattle. In our approach, the DNA genotyping of cow herds from 2 independent properties was performed using a high-density bovine SNP chip on DNA from pooled blood samples, grouped according to the result of a pregnancy test following their first and second joining opportunities. For the DNA pooling strategy, 15 to 28 blood samples from the same phenotype and contemporary group were allocated to pools. Across the 2 properties, a total of 183 pools were created representing 4,164 cows. In addition, blood samples from 309 bulls from the same properties were also taken. After genotyping and quality control, 74,584 remaining SNP were used for analyses. Pools and individual DNA samples were related by means of a "hybrid" genomic relationship matrix. The pooled genotyping analysis of 2 large and independent commercial populations of tropical beef cattle was able to recover significant and plausible associations between SNP and pregnancy test outcome. We discuss 24 SNP with significant association ( < 1.0 × 10) and mapped within 40 kb of an annotated gene. We have established a method to estimate the GEBV in young herd bulls for a trait that is currently unable to be predicted at all. In summary, our novel approach allowed us to conduct genomic analyses of fertility in 2 large commercial Brahman herds managed under extensive pastoral conditions.

  3. Analysis of the variability of extra-tropical cyclones at the regional scale for the coasts of Northern Germany and investigation of their coastal impacts

    Science.gov (United States)

    Schaaf, Benjamin; Feser, Frauke

    2015-04-01

    The evaluation of long-term changes in wind speeds is very important for the coastal areas and the protection measures. Therefor the wind variability at the regional scale for the coast of Northern Germany shall be analysed. In order to derive changes in storminess it is essential to analyse long, homogeneous meteorological time series. Wind measurements often suffer from inconsistencies which arise from changes in instrumentation, observation method, or station location. Reanalysis data take into account such inhomogeneities of observation data and convert these measurements into a consistent, gridded data set with the same grid spacing and time intervals. This leads to a smooth, homogeneous data set, but with relatively low resolution (about 210 km for the longest reanalysis data set, the NCEP reanalysis starting in 1948). Therefore a high-resolution regional atmospheric model will be used to bring these reanalyses to a higher resolution, using in addition to a dynamical downscaling approach the spectral nudging technique. This method 'nudges' the large spatial scales of the regional climate model towards the reanalysis, while the smaller spatial scales are left unchanged. It was applied successfully in a number of applications, leading to realistic atmospheric weather descriptions of the past. With the regional climate model COSMO-CLM a very high-resolution data set was calculated for the last 67 years, the period from 1948 until now. The model area is North Germany with the coastal area of the North sea and parts of the Baltic sea. This is one of the first model simulations on climate scale with a very high resolution of 2.8 km, so even small scale effects can be detected. With this hindcast-simulation there are numerous options of evaluation. One can create wind climatologies for regional areas such as for the metropolitan region of Hamburg. Otherwise one can investigate individual storms in a case study. With a filtering and tracking program the course of

  4. Tropical Cyclone Induced Air-Sea Interactions Over Oceanic Fronts

    Science.gov (United States)

    Shay, L. K.

    2012-12-01

    Recent severe tropical cyclones underscore the inherent importance of warm background ocean fronts and their interactions with the atmospheric boundary layer. Central to the question of heat and moisture fluxes, the amount of heat available to the tropical cyclone is predicated by the initial mixed layer depth and strength of the stratification that essentially set the level of entrainment mixing at the base of the mixed layer. In oceanic regimes where the ocean mixed layers are thin, shear-induced mixing tends to cool the upper ocean to form cold wakes which reduces the air-sea fluxes. This is an example of negative feedback. By contrast, in regimes where the ocean mixed layers are deep (usually along the western part of the gyres), warm water advection by the nearly steady currents reduces the levels of turbulent mixing by shear instabilities. As these strong near-inertial shears are arrested, more heat and moisture transfers are available through the enthalpy fluxes (typically 1 to 1.5 kW m-2) into the hurricane boundary layer. When tropical cyclones move into favorable or neutral atmospheric conditions, tropical cyclones have a tendency to rapidly intensify as observed over the Gulf of Mexico during Isidore and Lili in 2002, Katrina, Rita and Wilma in 2005, Dean and Felix in 2007 in the Caribbean Sea, and Earl in 2010 just north of the Caribbean Islands. To predict these tropical cyclone deepening (as well as weakening) cycles, coupled models must have ocean models with realistic ocean conditions and accurate air-sea and vertical mixing parameterizations. Thus, to constrain these models, having complete 3-D ocean profiles juxtaposed with atmospheric profiler measurements prior, during and subsequent to passage is an absolute necessity framed within regional scale satellite derived fields.

  5. Improving predictions of tropical forest response to climate change through integration of field studies and ecosystem modeling

    Science.gov (United States)

    Xiaohui Feng; María Uriarte; Grizelle González; Sasha Reed; Jill Thompson; Jess K. Zimmerman; Lora Murphy

    2018-01-01

    Tropical forests play a critical role in carbon and water cycles at a global scale. Rapid climate change is anticipated in tropical regions over the coming decades and, under a warmer and drier climate, tropical forests are likely to be net sources of carbon rather than sinks. However, our understanding of tropical forest response and feedback to climate change is very...

  6. Hospital-Based Coalition to Improve Regional Surge Capacity

    Directory of Open Access Journals (Sweden)

    James M. Learning

    2012-12-01

    Full Text Available Introduction: Surge capacity for optimization of access to hospital beds is a limiting factor in response to catastrophic events. Medical facilities, communication tools, manpower, and resource reserves exist to respond to these events. However, these factors may not be optimally functioning to generate an effective and efficient surge response. The objective was to improve the function of these factors.Methods: Regional healthcare facilities and supporting local emergency response agencies developed a coalition (the Healthcare Facilities Partnership of South Central Pennsylvania; HCFP¬SCPA to increase regional surge capacity and emergency preparedness for healthcare facilities. The coalition focused on 6 objectives: (1 increase awareness of capabilities and assets, (2 develop and pilot test advanced planning and exercising of plans in the region, (3 augment written medical mutual aid agreements, (4 develop and strengthen partnership relationships, (5 ensure National Incident Management System compliance, and (6 develop and test a plan for effective utilization of volunteer healthcare professionals.Results: In comparison to baseline measurements, the coalition improved existing areas covered under all 6 objectives documented during a 24-month evaluation period. Enhanced communications between the hospital coalition, and real-time exercises, were used to provide evidence of improved preparedness for putative mass casualty incidents.Conclusion: The HCFP-SCPA successfully increased preparedness and surge capacity through a partnership of regional healthcare facilities and emergency response agencies.

  7. Evidence based guidelines for complex regional pain syndrome type 1

    NARCIS (Netherlands)

    Perez, R.S.G.M.; Zollinger, P.E.; Dijkstra, P.U.; Thomassen-Hilgersom, I.L.; Zuurmond, W.W.A.; Rosenbrand, C.J.G.M.; Geerzen, J.H.B.

    2010-01-01

    Background: Treatment of complex regional pain syndrome type I (CRPS-I) is subject to discussion. The purpose of this study was to develop multidisciplinary guidelines for treatment of CRPS-I.Method: A multidisciplinary task force graded literature evaluating treatment effects for CRPS-I according

  8. Evidence based guidelines for complex regional pain syndrome type 1

    NARCIS (Netherlands)

    Perez, Roberto S.; Zollinger, Paul E.; Dijkstra, Pieter U.; Thomassen-Hilgersom, Ilona L.; Zuurmond, Wouter W.; Rosenbrand, Kitty C. J.; Geertzen, Jan H.

    2010-01-01

    Background: Treatment of complex regional pain syndrome type I (CRPS-I) is subject to discussion. The purpose of this study was to develop multidisciplinary guidelines for treatment of CRPS-I. Method: A multidisciplinary task force graded literature evaluating treatment effects for CRPS-I according

  9. Two-Step Downscaling of Trmm 3b43 V7 Precipitation in Contrasting Climatic Regions With Sparse Monitoring: The Case of Ecuador in Tropical South America

    Directory of Open Access Journals (Sweden)

    Jacinto Ulloa

    2017-07-01

    Full Text Available Spatial prediction of precipitation with high resolution is a challenging task in regions with strong climate variability and scarce monitoring. For this purpose, the quasi-continuous supply of information from satellite imagery is commonly used to complement in situ data. However, satellite images of precipitation are available at coarse resolutions, and require adequate methods for spatial downscaling and calibration. The objective of this paper is to introduce and evaluate a 2-step spatial downscaling approach for monthly precipitation applied to TRMM 3B43 (from 0 . 25 ∘ ≈ 27 km to 5 km resolution, resulting in 5 downscaled products for the period 01-2001/12-2011. The methodology was evaluated in 3 contrasting climatic regions of Ecuador. In step 1, bilinear resampling was applied over TRMM, and used as a reference product. The second step introduces further variability, and consists of four alternative gauge-satellite merging methods: (1 regression with in situ stations, (2 regression kriging with in situ stations, (3 regression with in situ stations and auxiliary variables, and (4 regression kriging with in situ stations and auxiliary variables. The first 2 methods only use the resampled TRMM data set as an independent variable. The last 2 methods enrich these models with auxiliary environmental factors, incorporating atmospheric and land variables. The results showed that no product outperforms the others in every region. In general, the methods with residual kriging correction outperformed the regression models. Regression kriging with situ data provided the best representation in the Coast, while regression kriging with in situ and auxiliary data generated the best results in the Andes. In the Amazon, no product outperformed the resampled TRMM images, probably due to the low density of in situ stations. These results are relevant to enhance satellite precipitation, depending on the availability of in situ data, auxiliary satellite

  10. Potential Environmental Justice (EJ) areas in Region 2 based on 2000 Census [EPA.EJAREAS_2000

    Data.gov (United States)

    U.S. Environmental Protection Agency — Potential Environmental Justice (EJ) areas in Region 2 . This dataset was derived from 2000 census data and based on the criteria setforth in the Region 2 Interim...

  11. Tropical savannas and dry forests.

    Science.gov (United States)

    Pennington, R Toby; Lehmann, Caroline E R; Rowland, Lucy M

    2018-05-07

    In the tropics, research, conservation and public attention focus on rain forests, but this neglects that half of the global tropics have a seasonally dry climate. These regions are home to dry forests and savannas (Figures 1 and 2), and are the focus of this Primer. The attention given to rain forests is understandable. Their high species diversity, sheer stature and luxuriance thrill biologists today as much as they did the first explorers in the Age of Discovery. Although dry forest and savanna may make less of a first impression, they support a fascinating diversity of plant strategies to cope with stress and disturbance including fire, drought and herbivory. Savannas played a fundamental role in human evolution, and across Africa and India they support iconic megafauna. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Inter-annual variability of aerosol optical depth over the tropical Atlantic Ocean based on MODIS-Aqua observations over the period 2002-2012

    Science.gov (United States)

    Gkikas, Antonis; Hatzianastassiou, Nikolaos

    2013-04-01

    The tropical Atlantic Ocean is affected by dust and biomass burning aerosol loads transported from the western parts of the Saharan desert and the sub-Sahel regions, respectively. The spatial and temporal patterns of this transport are determined by the aerosol emission rates, their deposition (wet and dry), by the latitudinal shift of the Intertropical Convergence Zone (ITCZ) and the prevailing wind fields. More specifically, in summer, Saharan dust aerosols are transported towards the Atlantic Ocean, even reaching the Gulf of Mexico, while in winter the Atlantic Ocean transport takes place in more southern latitudes, near the equator, sometimes reaching the northern parts of South America. In the later case, dust is mixed with biomass burning aerosols originating from agricultural activities in the sub-Sahel, associated with prevailing north-easterly airflow (Harmattan winds). Satellite observations are the appropriate tool for describing this African aerosol export, which is important to atmospheric, oceanic and climate processes, offering the advantage of complete spatial coverage. In the present study, we use satellite measurements of aerosol optical depth at 550nm (AOD550nm), on a daily and monthly basis, derived from MODIS-Aqua platform, at 1ox1o spatial resolution (Level 3), for the period 2002-2012. The primary objective is to determine the pixel-level and regional mean anomalies of AOD550nm over the entire study period. The regime of the anomalies of African export is interpreted in relation to the aerosol source areas, precipitation, wind patterns and temporal variability of the North Atlantic Oscillation Index (NAOI). In order to ensure availability of AOD over the Sahara desert, MODIS-Aqua Deep Blue products are also used. As for precipitation, Global Precipitation Climatology Project (GPCP) data at 2.5ox2.5o are used. The wind fields are taken from the National Center for Environmental Prediction (NCEP). Apart from the regime of African aerosol export

  13. Progress in tropical isotope dendroclimatology

    Science.gov (United States)

    Evans, M. N.; Schrag, D. P.; Poussart, P. F.; Anchukaitis, K. J.

    2005-12-01

    The terrestrial tropics remain an important gap in the growing high resolution proxy network used to characterize the mean state and variability of the hydrological cycle. Here we review early efforts to develop a new class of proxy paleorainfall/humidity indicators using intraseasonal to interannual-resolution stable isotope data from tropical trees. The approach invokes a recently published model of oxygen isotopic composition of alpha-cellulose, rapid methods for cellulose extraction from raw wood, and continuous flow isotope ratio mass spectrometry to develop proxy chronological, rainfall and growth rate estimates from tropical trees, even those lacking annual rings. Isotopically-derived age models may be confirmed for modern intervals using trees of known age, radiocarbon measurements, direct measurements of tree diameter, and time series replication. Studies are now underway at a number of laboratories on samples from Costa Rica, northwestern coastal Peru, Indonesia, Thailand, New Guinea, Paraguay, Brazil, India, and the South American Altiplano. Improved sample extraction chemistry and online pyrolysis techniques should increase sample throughput, precision, and time series replication. Statistical calibration together with simple forward modeling based on the well-observed modern period can provide for objective interpretation of the data. Ultimately, replicated data series with well-defined uncertainties can be entered into multiproxy efforts to define aspects of tropical hydrological variability associated with ENSO, the meridional overturning circulation, and the monsoon systems.

  14. Induced mutation in tropical fruit trees

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-05-15

    This publication is based on an FAO/IAEA coordinated research project (CRP) and provides insight into the application of induced mutation and in vitro techniques for the improvement of well known fruit trees such as citrus, mango, avocado and papaya, as well as more exotic fruit trees such as litchi, annona, jujube, carambola, pitanga and jaboticaba. The latter are of particular importance due to their adaptation to harsh environments and their high potential as basic food and micronutrient providers for populations in poorer and more remote regions. The findings of the CRP show that application of radiation induced mutation techniques in