WorldWideScience

Sample records for warm season mortality

  1. Winter Season Mortality: Will Climate Warming Bring Benefits?

    Science.gov (United States)

    Kinney, Patrick L.; Schwartz, Joel; Pascal, Mathilde; Petkova, Elisaveta; Tertre, Alain Le; Medina, Sylvia; Vautard, Robert

    2015-01-01

    Extreme heat events are associated with spikes in mortality, yet death rates are on average highest during the coldest months of the year. Under the assumption that most winter excess mortality is due to cold temperature, many previous studies have concluded that winter mortality will substantially decline in a warming climate. We analyzed whether and to what extent cold temperatures are associated with excess winter mortality across multiple cities and over multiple years within individual cities, using daily temperature and mortality data from 36 US cities (1985-2006) and 3 French cities (1971-2007). Comparing across cities, we found that excess winter mortality did not depend on seasonal temperature range, and was no lower in warmer vs. colder cities, suggesting that temperature is not a key driver of winter excess mortality. Using regression models within monthly strata, we found that variability in daily mortality within cities was not strongly influenced by winter temperature. Finally we found that inadequate control for seasonality in analyses of the effects of cold temperatures led to spuriously large assumed cold effects, and erroneous attribution of winter mortality to cold temperatures. Our findings suggest that reductions in cold-related mortality under warming climate may be much smaller than some have assumed. This should be of interest to researchers and policy makers concerned with projecting future health effects of climate change and developing relevant adaptation strategies. PMID:26495037

  2. Warm Season Temperature-Mortality Relationships in Chisinau (Moldova

    Directory of Open Access Journals (Sweden)

    Roman Corobov

    2013-01-01

    Full Text Available Results of the epidemiological study of relationships between air temperature and daily mortality in Chisinau (Moldova are presented. The research’s main task included description of mortality dependence on different temperature variables and identification of thermal optimum (minimal mortality temperature, MMT. Total daily deaths were used to characterize the mortality of urban and rural populations in April–September of 2000–2008, excluding the extremely warm season of 2007. The simple moving average procedure and 2nd-order polynomials were used for daily mean (Tmean, maximum (Tmax, and minimum (Tmin temperatures and mortality approximation. Thermal optimum for mortality in Chisinau (15.2 deaths was observed at Tmean, Tmax, and Tmin about 22°C, 27-28°C, and 17-18°C, respectively. Considering these values as certain cut-points, the correlations between temperature and mortality were estimated below and above MMTs. With air temperatures below its optimal value, each additional 1°C increase of Tmean (Tmax, Tmin was accompanied by 1.40% (1.35%, 1.52% decrease in daily mortality. The increase of Tmean and Tmax above optimal values was associated with ~2.8% and 3.5% increase of mortality; results for Tmin were not statistically significant. The dependency of mortality on apparent temperature was somewhat weaker below MMT; a significant relationship above MMT was not identified.

  3. Seasonal heterogeneity of ocean warming: a mortality sink for ectotherm colonizers

    Science.gov (United States)

    Maffucci, Fulvio; Corrado, Raffaele; Palatella, Luigi; Borra, Marco; Marullo, Salvatore; Hochscheid, Sandra; Lacorata, Guglielmo; Iudicone, Daniele

    2016-01-01

    Distribution shifts are a common adaptive response of marine ectotherms to climate change but the pace of redistribution depends on species-specific traits that may promote or hamper expansion to northern habitats. Here we show that recently, the loggerhead turtle (Caretta caretta) has begun to nest steadily beyond the northern edge of the species’ range in the Mediterranean basin. This range expansion is associated with a significant warming of spring and summer sea surface temperature (SST) that offers a wider thermal window suitable for nesting. However, we found that post-hatchlings departing from this location experience low winter SST that may affect their survival and thus hamper the stabilization of the site by self-recruitment. The inspection of the Intergovernmental Panel on Climate Change model projections and observational data on SST trends shows that, despite the annual warming for this century, winter SST show little or no trends. Therefore, thermal constraints during the early developmental phase may limit the chance of population growth at this location also in the near future, despite increasingly favourable conditions at the nesting sites. Quantifying and understanding the interplay between dispersal and environmental changes at all life stages is critical for predicting ectotherm range expansion with climate warming. PMID:27044321

  4. Climate change-related temperature impacts on warm season heat mortality: a proof-of-concept methodology using BenMAP.

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    Voorhees, A Scott; Fann, Neal; Fulcher, Charles; Dolwick, Patrick; Hubbell, Bryan; Bierwagen, Britta; Morefield, Philip

    2011-02-15

    Climate change is anticipated to raise overall temperatures and is likely to increase heat-related human health morbidity and mortality risks. The objective of this work was to develop a proof-of-concept approach for estimating excess heat-related premature deaths in the continental United States resulting from potential changes in future temperature using the BenMAP model. In this approach we adapt the methods and tools that the US Environmental Protection Agency uses to assess air pollution health impacts by incorporating temperature modeling and heat mortality health impact functions. This new method demonstrates the ability to apply the existing temperature-health literature to quantify prospective changes in climate-sensitive heat-related mortality. We compared estimates of future temperature with and without climate change and applied heat-mortality health functions to estimate relative changes in heat-related premature mortality. Using the A1B emissions scenario, we applied the GISS-II global circulation model downscaled to 36-km using MM5 and formatted using the Meteorology-Chemistry Interface Processor. For averaged temperatures derived from the 5 years 2048-2052 relative to 1999-2003 we estimated for the warm season May-September a national U.S. estimate of annual incidence of heat-related mortality to be 3700-3800 from all causes, 3500 from cardiovascular disease, and 21 000-27 000 from nonaccidental death, applying various health impact functions. Our estimates of mortality, produced to validate the application of a new methodology, suggest the importance of quantifying heat impacts in economic assessments of climate change.

  5. Seasonal association between ambient ozone and mortality in Zhengzhou, China

    Science.gov (United States)

    Qin, Lijie; Gu, Jianqin; Liang, Shijie; Fang, Fang; Bai, Weimin; Liu, Xu; Zhao, Tao; Walline, Joseph; Zhang, Shenglong; Cui, Yingjie; Xu, Yaxin; Lin, Hualiang

    2016-12-01

    Different seasonal health effects of ambient ozone (O3) have been reported in previous studies. This might be due to inappropriate adjustment of temperature in different seasons. We used daily data on non-accidental mortality and ambient air pollution in Zhengzhou from January 19, 2013 to June 30, 2015. Season-stratified analyses using generalized additive models were conducted to evaluate the seasonal associations with adjustment of temperature with different lagged days (lag0-1 for warm season, lag0-14 for cold season). We recorded a total of 70,443 non-accidental deaths in Zhengzhou during the study period. Significant associations were observed between ambient O3 and mortality in cold season. Every 10-μg/m3 increment of 24-h O3 of 1-day lagged time was associated with a 1.38% (95% CI 0.60, 2.16%) increase in all cause mortality, 1.35% (95% CI 0.41, 2.30%) increase in cardiovascular mortality, and 1.78% (95% CI 0.43, 3.14%) increase in respiratory mortality. Similar associations were observed when using daily 1- and 8-h maximum concentrations of O3. No significant association was found during warm season. This study suggests a more pronounced ozone-mortality association in cold season in Zhengzhou, and we suggest that different lagged temperatures should be considered when examining the seasonal health effects of ambient ozone.

  6. Establishing native warm season grasses on Eastern Kentucky strip mines

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    Barnes, T.G.; Larkin, J.L.; Arnett, M.B. [Univ. of Kentucky, Lexington, KY (United States). Dept. of Forestry

    1998-12-31

    The authors evaluated various methods of establishing native warm season grasses on two reclaimed Eastern Kentucky mines from 1994--1997. Most current reclamation practices incorporate the use of tall fescue (Festuca arundinacea) and other cool-season grasses/legumes that provide little wildlife habitats. The use of native warm season grasses will likely improve wildlife habitat on reclaimed strip mines. Objectives of this study were to compare the feasibility of establishing these grasses during fall, winter, or spring using a native rangeland seeder or hydroseeding; a fertilizer application at planting; or cold-moist stratification prior to hydroseeding. Vegetative cover, bare ground, species richness, and biomass samples were collected at the end of each growing season. Native warm season grass plantings had higher plant species richness compared to cool-season reclamation mixtures. There was no difference in establishment of native warm season grasses as a result of fertilization or seeding technique. Winter native warm season grass plantings were failures and cold-moist stratification did not increase plant establishment during any season. As a result of a drought during 1997, both cool-season and warm season plantings were failures. Cool-season reclamation mixtures had significantly more vegetative cover and biomass compared to native warm season grass mixtures and the native warm season grass plantings did not meet vegetative cover requirements for bond release. Forbs and legumes that established well included pale purple coneflower (Echinacea pallida), lance-leaf coreopsis (Coreopsis lanceolata), round-headed lespedeza (Lespedeza capitata), partridge pea (Cassia fasiculata), black-eyed susan (Rudbeckia hirta), butterfly milkweed (Asclepias tuberosa), and bergamot (Monarda fistulosa). Results from two demonstration plots next to research plots indicate it is possible to establish native warm season grasses on Eastern Kentucky strip mines for wildlife habitat.

  7. The Seasonal Timing of Stratospheric Sudden Warmings

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    Horan, Matthew; Reichler, Thomas

    2017-04-01

    We aim to diagnose causes for the differences in the seasonal distribution of stratospheric sudden warmings (SSWs) between reanalysis and models. Observations over the past 60 years indicate that most SSWs occur during mid-winter (January), but climate models tend to simulate the maximum number of SSWs during late-winter or early-spring. This discrepancy has led to the speculation that models might be flawed and that the simulation of a January maximum represents a measure of model performance. However, the relatively short observational record and rare occurrence of SSWs also implies considerable uncertainty in the observation derived result. The goal of this work is to understand the seasonal distribution of SSWs using a simple statistical model, to test the model using a variety of data sets, and to answer the questions when SSWs are most likely to occur and what the reasons for it are. Our analysis is based on Charlton and Polvani's (2007) criteria for SSWs and on the assumption that the polar vortex wind approximately follows a normal distribution. The statistical model successfully predicts the day-to-day variations in the empirically derived occurrence frequency of SSWs, demonstrating that the seasonal distribution of SSWs can be almost entirely understood in terms of the climatological seasonal cycle of the polar vortex wind. The statistical model indicates that the maximum frequency of SSWs in climate models and reanalysis occurs during late-winter, and not during mid-winter as implied by the observations. This strongly suggests that sampling uncertainty is responsible for the January maximum seen in the reanalysis and that the simulation of a January maximum does not represent a metric of model performance. The reason for the late-winter maximum is the decreasing strength of the polar vortex, making it more likely that the winds of the polar vortex reach the zero-threshold required by the WMO definition for SSWs. This further suggests that climatological

  8. On bimodality in warm season soil moisture observations

    NARCIS (Netherlands)

    Teuling, A.J.; Uijlenhoet, R.; Troch, P.A.A.

    2005-01-01

    It has recently been suggested that the bimodality in warm season soil moisture observations in Illinois is evidence of a soil moisture-precipitation feedback. Other studies however provide little evidence for a strong feedback in this region. Here we show that seasonality in the meteorological cond

  9. Global warming induced hybrid rainy seasons in the Sahel

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    Salack, Seyni; Klein, Cornelia; Giannini, Alessandra; Sarr, Benoit; Worou, Omonlola N.; Belko, Nouhoun; Bliefernicht, Jan; Kunstman, Harald

    2016-10-01

    The small rainfall recovery observed over the Sahel, concomitant with a regional climate warming, conceals some drought features that exacerbate food security. The new rainfall features include false start and early cessation of rainy seasons, increased frequency of intense daily rainfall, increasing number of hot nights and warm days and a decreasing trend in diurnal temperature range. Here, we explain these mixed dry/wet seasonal rainfall features which are called hybrid rainy seasons by delving into observed data consensus on the reduction in rainfall amount, its spatial coverage, timing and erratic distribution of events, and other atmospheric variables crucial in agro-climatic monitoring and seasonal forecasting. Further composite investigations of seasonal droughts, oceans warming and the regional atmospheric circulation nexus reveal that the low-to-mid-level atmospheric winds pattern, often stationary relative to either strong or neutral El-Niño-Southern-Oscillations drought patterns, associates to basin warmings in the North Atlantic and the Mediterranean Sea to trigger hybrid rainy seasons in the Sahel. More challenging to rain-fed farming systems, our results suggest that these new rainfall conditions will most likely be sustained by global warming, reshaping thereby our understanding of food insecurity in this region.

  10. Comparing pandemic to seasonal influenza mortality: moderate impact overall but high mortality in young children.

    NARCIS (Netherlands)

    Wijngaard, C.C. van den; Asten, L. van; Koopmans, M.P.G.; Pelt, W. van; Nagelkerke, N.J.D.; Wielders, C.C.H.; Lier, A. van; Hoek, W. van der; Meijer, A.; Donker, G.A.; Dijkstra, F.; Harmsen, C.; Sande, M.A.B. van der; Kretzschmar, M.

    2012-01-01

    Background: We assessed the severity of the 2009 influenza pandemic by comparing pandemic mortality to seasonal influenza mortality. However, reported pandemic deaths were laboratory-confirmed - and thus an underestimation - whereas seasonal influenza mortality is often more inclusively estimated. F

  11. The seasonal timing of warming that controls onset of the growing season.

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    Clark, James S; Melillo, Jerry; Mohan, Jacqueline; Salk, Carl

    2014-04-01

    Forecasting how global warming will affect onset of the growing season is essential for predicting terrestrial productivity, but suffers from conflicting evidence. We show that accurate estimates require ways to connect discrete observations of changing tree status (e.g., pre- vs. post budbreak) with continuous responses to fluctuating temperatures. By coherently synthesizing discrete observations with continuous responses to temperature variation, we accurately quantify how increasing temperature variation accelerates onset of growth. Application to warming experiments at two latitudes demonstrates that maximum responses to warming are concentrated in late winter, weeks ahead of the main budbreak period. Given that warming will not occur uniformly over the year, knowledge of when temperature variation has the most impact can guide prediction. Responses are large and heterogeneous, yet predictable. The approach has immediate application to forecasting effects of warming on growing season length, requiring only information that is readily available from weather stations and generated in climate models. © 2013 John Wiley & Sons Ltd.

  12. Small mammal use of native warm-season and non-native cool-season grass forage fields

    Science.gov (United States)

    Ryan L Klimstra,; Christopher E Moorman,; Converse, Sarah J.; Royle, J. Andrew; Craig A Harper,

    2015-01-01

    Recent emphasis has been put on establishing native warm-season grasses for forage production because it is thought native warm-season grasses provide higher quality wildlife habitat than do non-native cool-season grasses. However, it is not clear whether native warm-season grass fields provide better resources for small mammals than currently are available in non-native cool-season grass forage production fields. We developed a hierarchical spatially explicit capture-recapture model to compare abundance of hispid cotton rats (Sigmodon hispidus), white-footed mice (Peromyscus leucopus), and house mice (Mus musculus) among 4 hayed non-native cool-season grass fields, 4 hayed native warm-season grass fields, and 4 native warm-season grass-forb ("wildlife") fields managed for wildlife during 2 summer trapping periods in 2009 and 2010 of the western piedmont of North Carolina, USA. Cotton rat abundance estimates were greater in wildlife fields than in native warm-season grass and non-native cool-season grass fields and greater in native warm-season grass fields than in non-native cool-season grass fields. Abundances of white-footed mouse and house mouse populations were lower in wildlife fields than in native warm-season grass and non-native cool-season grass fields, but the abundances were not different between the native warm-season grass and non-native cool-season grass fields. Lack of cover following haying in non-native cool-season grass and native warm-season grass fields likely was the key factor limiting small mammal abundance, especially cotton rats, in forage fields. Retention of vegetation structure in managed forage production systems, either by alternately resting cool-season and warm-season grass forage fields or by leaving unharvested field borders, should provide refugia for small mammals during haying events.

  13. Seasonal variation in child mortality in rural Guinea-Bissau.

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    Nielsen, Bibi Uhre; Byberg, Stine; Aaby, Peter; Rodrigues, Amabelia; Benn, Christine Stabell; Fisker, Ane Baerent

    2017-07-01

    In many African countries, child mortality is higher in the rainy season than in the dry season. We investigated the effect of season on child mortality by time periods, sex and age in rural Guinea-Bissau. Bandim health project follows children under-five in a health and demographic surveillance system in rural Guinea-Bissau. We compared the mortality in the rainy season (June to November) between 1990 and 2013 with the mortality in the dry season (December to May) in Cox proportional hazards models providing rainy vs. dry season mortality rate ratios (r/d-mrr). Seasonal effects were estimated in strata defined by time periods with different frequency of vaccination campaigns, sex and age (<1 month, 1-11 months, 12-59 months). Verbal autopsies were interpreted using InterVa-4 software. From 1990 to 2013, overall mortality was declined by almost two-thirds among 81 292 children (10 588 deaths). Mortality was 51% (95% ci: 45-58%) higher in the rainy season than in the dry season throughout the study period. The seasonal difference increased significantly with age, the r/d-mrr being 0.94 (0.86-1.03) among neonates, 1.57 (1.46-1.69) in post-neonatal infants and 1.83 (1.72-1.95) in under-five children (P for same effect <0.001). According to the InterVa, malaria deaths were the main reason for the seasonal mortality difference, causing 50% of all deaths in the rainy season, but only if the InterVa included season of death, making the argument self-confirmatory. The mortality declined throughout the study, yet rainy season continued to be associated with 51% higher overall mortality. © 2017 The Authors. Tropical Medicine & International Health Published by John Wiley & Sons Ltd.

  14. Statistical significance of seasonal warming/cooling trends

    Science.gov (United States)

    Ludescher, Josef; Bunde, Armin; Schellnhuber, Hans Joachim

    2017-04-01

    The question whether a seasonal climate trend (e.g., the increase of summer temperatures in Antarctica in the last decades) is of anthropogenic or natural origin is of great importance for mitigation and adaption measures alike. The conventional significance analysis assumes that (i) the seasonal climate trends can be quantified by linear regression, (ii) the different seasonal records can be treated as independent records, and (iii) the persistence in each of these seasonal records can be characterized by short-term memory described by an autoregressive process of first order. Here we show that assumption ii is not valid, due to strong intraannual correlations by which different seasons are correlated. We also show that, even in the absence of correlations, for Gaussian white noise, the conventional analysis leads to a strong overestimation of the significance of the seasonal trends, because multiple testing has not been taken into account. In addition, when the data exhibit long-term memory (which is the case in most climate records), assumption iii leads to a further overestimation of the trend significance. Combining Monte Carlo simulations with the Holm-Bonferroni method, we demonstrate how to obtain reliable estimates of the significance of the seasonal climate trends in long-term correlated records. For an illustration, we apply our method to representative temperature records from West Antarctica, which is one of the fastest-warming places on Earth and belongs to the crucial tipping elements in the Earth system.

  15. Warm-season severe wind events in Germany

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    Gatzen, Christoph

    2013-04-01

    A 15-year data set of wind measurements was analyzed with regard to warm season severe wind gusts in Germany. For April to September of the years 1997 to 2011, 1035 wind measurements of 26 m/s or greater were found. These wind reports were associated with 268 wind events. In total, 252 convective wind events contributed to 837 (81%) of the wind reports, 16 non-convective synoptic-scale wind events contributed to 198 reports (19%). Severe wind events were found with synoptic situations characterized by rather strong mid-level flow and advancing mid-level troughs. Severe convective wind events were analyzed using radar images and classified with respect to the observed radar structure. The most important convective mode was squall lines that were associated with one third of all severe wind gusts, followed by groups, bow echo complexes, and bow echoes. Supercells and cells were not associated with many wind reports. The low contribution of isolated cells indicates that rather large-scale forcing by synoptic-scale features like fronts is important for German severe wind events. Bow echoes were found to be present for 58% of all wind reports. The movement speed of bow echoes indicated a large variation with a maximum speed of 33 m/s. Extreme wind events as well as events with more than 15 wind reports were found to be related to higher movement speeds. Concentrating on the most intense events, derechos seem to be very important to the warm season wind threat in Germany. Convective events with a path length of more than 400 km contributed to 36% of all warm-season wind gusts in this data set. Furthermore, eight of nine extreme gusts exceeding 40 m/s were recorded with derecho events.

  16. Alpine proglacial suspended sediment dynamics in warm and cool ablation seasons: Implications for global warming

    Science.gov (United States)

    Stott, Tim; Mount, Nick

    2007-01-01

    SummaryData on suspended sediment dynamics and loads obtained from the Torrent du Glacier Noir, Ecrins Massif, SE France, during the unusually warm 2003 and cooler 2004 ablation seasons are used to indicate the likely future impacts of climate warming on suspended sediment transport processes in temperate Alpine proglacial zones. Suspended sediment concentration (SSC) and discharge ( Q) were continuously monitored for 16-day periods during July 2003 and July 2004. SSC was monitored by automated pump sampling during diurnal events in each season and supplemented by a 10 min turbidity record. Q was monitored at a range of flows and a rating curve used to convert a 10 min water level record into Q. Air temperature (AT) was also logged at 10 min intervals throughout the study. Comparison of the 2003 and 2004 monitoring periods showed that daily mean AT measured at the site was 1.2 °C higher in 2003, mean Q was 2.3 times higher, and the suspended sediment load (SSL) was between 3.1 and 4.1 times greater in July 2003 than for the same period in the 2004 ablation season. There is an increase in SSC during the 2004 observation period which is less apparent in 2003, most likely because higher ATs and consequently higher Q earlier in the 2003 melt season had removed available sediment before the study took place in July. The rating curve method for estimating SSL produced a total load for the 16-day study period in 2003 which, when corrected upwards to account for statistical bias, was 10 314 ± 743 t or 95% of the load estimated from the turbidity record for the same period. In 2004 the corrected SSC- Q rating curve estimate was 2504 ± 126 t while the estimate from the turbidity record was 743 ± 112 t though a more sensitive turbidity sensor produced a higher estimate of 3474 ± 302 t. While the different SSL estimation methods in 2004 are not in perfect agreement, the contrast between the two seasons is nevertheless very clear, and is largely attributed to a mean

  17. Seasonal variation in child mortality in rural Guinea-Bissau

    DEFF Research Database (Denmark)

    Nielsen, Bibi Uhre; Byberg, Stine; Aaby, Peter

    2017-01-01

    81 292 children (10 588 deaths). Mortality was 51% (95% ci: 45-58%) higher in the rainy season than in the dry season throughout the study period. The seasonal difference increased significantly with age, the r/d-mrr being 0.94 (0.86-1.03) among neonates, 1.57 (1.46-1.69) in post-neonatal infants...... and 1.83 (1.72-1.95) in under-five children (P for same effect deaths were the main reason for the seasonal mortality difference, causing 50% of all deaths in the rainy season, but only if the InterVa included season of death, making the argument self...

  18. Warm season tree growth and precipitation over Mexico

    Science.gov (United States)

    Therrell, Matthew D.; Stahle, David W.; Cleaveland, Malcolm K.; Villanueva-Diaz, Jose

    2002-07-01

    We have developed a network of 18 new tree ring chronologies to examine the history of warm season tree growth over Mexico from 1780 to 1992. The chronologies include Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) and Montezuma pine (Pinus montezumae Lamb.) latewood width, and Montezuma bald cypress (Taxodium mucronatum Ten.) total ring width. They are located in southwestern Texas, the Sierra Madre Oriental, Sierra Madre Occidental, and southern Mexico as far south as Oaxaca. Seven of these chronologies are among the first precipitation sensitive tree ring records from the American tropics. Principal component analysis of the chronologies indicates that the primary modes of tree growth variability are divided north and south by the Tropic of Cancer. The tree ring data in northern Mexico (PC1) are most sensitive to June-August rainfall, while the data from southern Mexico (PC2) are sensitive to rainfall in April-June. We find that the mode of tree growth variability over southern Mexico is significantly correlated with the onset of the North American Monsoon. Anomalies in monsoon onset, spring precipitation, and tree growth in southern Mexico all tend to be followed by precipitation anomalies of opposite sign later in the summer over most of central Mexico.

  19. Seasonal mortality variations of cardiovascular, respiratory and malignant diseases in the City of Belgrade

    Directory of Open Access Journals (Sweden)

    Stanišić-Stojić Svetlana

    2016-01-01

    cardiovascular diseases increased twice, namely at the end of June and October, which is assumed to be the result of sudden temperature changes. Nonetheless, no such seasonal variations were observed in mortality caused by cancer. Seasonal variations in mortality resulting from cardiovascular diseases also indicate gender differences, which is why sudden temperature changes in interim periods affect more women than men. As regards deseasonalized trend, mortality caused by cardiovascular diseases stagnates, while mortality caused by cancer and mortality caused by respiratory diseases records moderate to severe increase. This is a uniform trend in almost all municipalities in Belgrade, with average mortality rates being higher in central zones than in suburbs over the last 15 years, particularly mortality caused by cancer. A slight increase in the overall mortality can also be attributed to aging of the population, which cannot be verified due to lack of available accurate data on the average age structure of Belgrade population for the observed period. A better understanding of seasonal variations in mortality caused by chronic non-communicable diseases can contribute to improving the population health care and rising awareness of the population concerning greater health care in changeable weather conditions due to global warming and climate change. These findings can also enhance preventive action on environmental risk factors that are not limited exclusively to weather conditions, such as air pollution.

  20. SEASONAL MORTALITY PATTERNS IN NON-HUMAN PRIMATES: IMPLICATIONS FOR VARIATION IN SELECTION PRESSURES ACROSS ENVIRONMENTS

    Science.gov (United States)

    Gogarten, Jan F.; Brown, Leone M.; Chapman, Colin A.; Cords, Marina; Doran-Sheehy, Diane; Fedigan, Linda M.; Grine, Frederick E.; Perry, Susan; Pusey, Anne E.; Sterck, Elisabeth H. M.; Wich, Serge A.; Wright, Patricia C.

    2014-01-01

    Examining seasonal mortality patterns can yield insights into the drivers of mortality and thus potential selection pressures acting on individuals in different environments. We compiled adult and juvenile mortality data from nine wild non-human primate taxa to investigate the role of seasonality in patterns of mortality and address the following questions: Is mortality highly seasonal across species? Does greater environmental seasonality lead to more seasonal mortality patterns? If mortality is seasonal, is it higher during wet seasons or during periods of food scarcity? and Do folivores show less seasonal mortality than frugivores? We found seasonal mortality patterns in five of nine taxa, and mortality was more often tied to wet seasons than food-scarce periods, a relationship that may be driven by disease. Controlling for phylogeny, we found a positive relationship between the degree of environmental seasonality and mortality, with folivores exhibiting more seasonal mortality than frugivores. These results suggest that mortality patterns are influenced both by diet and degree of environmental seasonality. Applied to a wider array of taxa, analyses of seasonal mortality patterns may aid understanding of life-history evolution and selection pressures acting across a broad spectrum of environments and spatial and temporal scales. PMID:23025613

  1. Magnitude and pattern of Arctic warming governed by the seasonality of radiative forcing

    Science.gov (United States)

    Bintanja, Richard; Krikken, Folmer

    2015-04-01

    Observed and projected climate warming is strongest in the Arctic regions, and maximum in autumn/winter. Attempts to explain this feature have focused primarily on identifying the associated climate feedbacks, particularly the ice-albedo and lapse-rate feedbacks. However, the impact of seasonally varying climate forcing has not been identified and quantified. Here we use a state-of-the-art global climate model in idealized seasonal forcing simulations to show that Arctic warming is very sensitive to the season in which the radiative forcing occurs. More specifically, Arctic warming and sea ice decline (especially in winter) are particularly sensitive to forcing in spring, during which the energy is effectively 'absorbed' by the ocean (through sea ice melt and ocean warming, amplified by the ice-albedo feedback) and consequently released to the lower atmosphere in autumn and winter, mainly along the sea ice periphery. In contrast, wintertime radiative forcing yields a more evenly distributed winter warming, which, surprisingly, in certain regions is even smaller than that due to spring forcing. The dependence of the magnitude and pattern of Arctic warming on the seasonality of the climate forcing has important implications in terms of projected increases in anthropogenic forcing. For instance, shipping-induced emissions such as those of black carbon are projected to peak in the ice-free summer and will thereby exert a comparatively strong impact on Arctic warming.

  2. The Great Season Climatic Oscillation and the Global Warming

    CERN Document Server

    Boucenna, Ahmed

    2008-01-01

    The present earth warming up is often explained by the atmosphere gas greenhouse effect. This explanation is in contradiction with the thermodynamics second law. The warming up by greenhouse effect is quite improbable. It is cloud reflection that gives to the earth s ground its 15 degres C mean temperature. Since the reflection of the radiation by gases is negligible, the role of the atmosphere greenhouse gases in the earth warming up by earth radiation reflection loses its importance. We think that natural climatic oscillations contribute more to earth climatic disturbances. The oscillation that we hypothesize to exist has a long period (800 to 1000 years). The glacier melting and regeneration cycles lead to variations in the cold region ocean water density and thermal conductibility according to their salinity. These variations lead one to think about a macro climate oscillating between maximum hot and minimum cold temperatures. This oscillation is materialized by the passages of the planet through hot, mil...

  3. The effects of two different types of clothing on seasonal warm acclimatization

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    Li, X.; Tokura, H.; Midorikawa, T.

    1995-09-01

    The work described in this paper investigates the effects of two types of clothing leaving the legs covered or uncovered, on seasonal warm acclimatization in women. Experiments were carried out to observe the differences in thermal responses between two groups of subjects who dressed themselves in trousers or kneelength skirts during the daytime for 3 months from April to June. Rectal temperatures in the subjects wearing skirts were found to be shifted to higher levels when the season gradually became warmer from spring to summer. The results suggest that the clothing type worn in daily life may play an important role in the seasonal warm acclimatization of thermal responses in humans.

  4. A new mechanism for warm-season precipitation response to global warming based on convection-permitting simulations

    Science.gov (United States)

    Dai, Aiguo; Rasmussen, Roy M.; Liu, Changhai; Ikeda, Kyoko; Prein, Andreas F.

    2017-08-01

    Climate models project increasing precipitation intensity but decreasing frequency as greenhouse gases increase. However, the exact mechanism for the frequency decrease remains unclear. Here we investigate this by analyzing hourly data from regional climate change simulations with 4 km grid spacing covering most of North America using the Weather Research and Forecasting model. The model was forced with present and future boundary conditions, with the latter being derived by adding the CMIP5 19-model ensemble mean changes to the ERA-interim reanalysis. The model reproduces well the observed seasonal and spatial variations in precipitation frequency and histograms, and the dry interval between rain events over the contiguous US. Results show that overall precipitation frequency indeed decreases during the warm season mainly due to fewer light-moderate precipitation (0.1 10 mm/h) events increase. Dry spells become longer and more frequent, together with a reduction in time-mean relative humidity (RH) in the lower troposphere during the warm season. The increased dry hours and decreased RH lead to a reduction in overall precipitation frequency and also for light-moderate precipitation events, while water vapor-induced increases in precipitation intensity and the positive latent heating feedback in intense storms may be responsible for the large increase in intense precipitation. The size of intense storms increases while their number decreases in the future climate, which helps explain the increase in local frequency of heavy precipitation. The results generally support a new hypothesis for future warm-season precipitation: each rainstorm removes ≥7% more moisture from the air per 1 K local warming, and surface evaporation and moisture advection take slightly longer than currently to replenish the depleted moisture before the next storm forms, leading to longer dry spells and a reduction in precipitation frequency, as well as decreases in time-mean RH and vertical

  5. The impact of global warming on health and mortality.

    Science.gov (United States)

    Keatinge, W R; Donaldson, G C

    2004-11-01

    Initial concern about the possible effects of global warming on infections has declined with the realization that the spread of tropical diseases is likely to be limited and controllable. However, the direct effects of heat already cause substantial numbers of deaths among vulnerable people in the summer. Action to prevent these deaths from rising is the most obvious medical challenge presented by a global rise in temperature. Strategies to prevent such deaths are in place to some extent, and they differ between the United States and Europe. Air conditioning has reduced them in the United States, and older technologies such as fans, shade, and buildings designed to keep cool on hot days have generally done so in Europe. Since the energy requirements of air conditioning accelerate global warming, a combination of the older methods, backed up by use of air conditioning when necessary, can provide the ideal solution. Despite the availability of these technologies, occasional record high temperatures still cause sharp rises in heat-related deaths as the climate warms. The most important single piece of advice at the time a heat wave strikes is that people having dangerous heat stress need immediate cooling, eg, by a cool bath. Such action at home can be more effective than transporting the patient to hospital. Meanwhile, it must not be forgotten that cold weather in winter causes-many more deaths than heat in summer, even in most subtropical regions, and measures to control cold-related deaths need to continue.

  6. Seasonal and diurnal variability in historical warming due to the urbanization of Hokkaido, Japan

    Science.gov (United States)

    Sugimoto, Shiori; Sato, Tomonori; Sasaki, Tomonori

    2015-06-01

    The influence of historical urbanization on warming trends observed on Hokkaido Island (Japan) is discussed with an emphasis on seasonally and diurnally differential responses of air temperature to urban effects. Two numerical experiments using past and current land use scenarios successfully simulated the observed temperature trends, showing a greater rate of warming in winter than in summer and a greater increase in daily minimum than daily maximum temperatures. The results suggest that seasonal and diurnal variations in the thermal structure of the planetary boundary layer play a leading role in determining the warming rate of surface air. Under strongly stable stratification, anomalous heating within the urban canopy dissipates into a near-surface shallow layer, resulting in increased daily minimum temperatures during winter. In summer, however, anomalous urban heating due to increased Bowen ratios is attenuated by vertical mixing in the convective daytime boundary layer, suppressing the impact of urban heating on surface warming.

  7. Novel Application of ALMANAC: Modelling a Functional Group, Exotic Warm-season Perennial Grasses

    OpenAIRE

    Kiniry, J. R.; Johnson, M. V. V.; Venuto, B. C. (deceased); Burson, B. L.

    2013-01-01

    Aim: To determine the efficacy of the ALMANAC model in simulating leaf canopy growth and biomass production of a plant functional group, specifically “exotic warm-season perennial grasses,” represented by buffelgrass [Pennisetum ciliare (L.) Link] and “Old World Bluestems” (Bothriochloa Kuntze, Capillipedium Stapf, and Dichanthium Willemet). Study Design: Leaf area index (LAI) over the growing season, the light extinction coefficient (k) for Beer's Law, and the rad...

  8. Annual warm-season grasses vary for forage yield, quality, and competitiveness with weeds

    Science.gov (United States)

    Warm-season annual grasses may be suitable as herbicide-free forage crops. A two-year field study was conducted to determine whether tillage system and nitrogen (N) fertilizer application method influenced crop and weed biomass, water use, water use efficiency (WUE), and forage quality of three war...

  9. Nutritive value and fermentation parameters of warm-season grass silage

    Science.gov (United States)

    The objective of this study was to investigate the nutritive value and fermentation characteristics of different species of warm-season grass silages treated with or without bacterial inoculants in the summer and fall. Nine forage species and cultivars, elephantgrass (Pennisetum purpureum Schumach),...

  10. Seasonal variation and formation mechanism of the South China Sea warm water

    Institute of Scientific and Technical Information of China (English)

    刘秦玉; 王东晓; 贾英来; 杨海军; 孙即霖; 杜岩

    2002-01-01

    -- The South China Sea warm water (SCSWW) is identified as the warm water body with temperature no less than 28C. There are three stages in the seasonal variation of the SCSWW. The SCSWW expands rapidly and deepens quickly in the developing stage. The warm water thickness decreases near the coast of Vietnam and increases near Palawan Island in the steady stage. The SCSWW flinches southward while its thickness off Palawan Island remains no less than 50 m in the flinching stage. The maximum thickness of the SCSWW is always located near the southeastern SCS. The seasonal variation of the SCSWW has a close relationship with seasonal variation of the thermocline. According to the analysis of the numerical experiment results from the Princeton Ocean Model (POM),the mechanism of the seasonal variation of the SCSWW can be interpreted as: ( 1 ) in the developing stage, the rapidly expanding and thickening feature of the SCSWW is mainly due to buoyancy flux effect (67% contribution). The weak wind and anticyclonic wind stress curl (22% contribution) present an environment which facilitates the accumulation of warm water; (2) in the steady stage, the decrease feature near the Vietnam coast and increase eature in southeast of the SCSWW thickness are mainly caused by wind stress (70% contribution); (3) in the flinching stage, the thickness reduction of the SCSWW is mainly due to upwelling and enhanced turbulent mixing caused by wind stress accounts for 60% ).

  11. HAIL EPISODES AT METEOROLOGICAL STATION CRAIOVA DURING THE WARM SEASON

    Directory of Open Access Journals (Sweden)

    BĂCESCU ADRIANA

    2015-03-01

    Full Text Available The paper presents a statistical, climatological study of the occurrence of hail phenomenon at Craiova- one of the representative stations in Oltenia region – during months May-August in the period 1981-2010. The results show that the month with most hail cases during the period analyzed is June, while the largest frequency of occurrence corresponds to time interval 13:30-14:30 UTC; regarding the dimensions of hail, in most cases the hail particles presented diameters up to 5 mm. From a synoptic point of view, the frequency of thermal convection as trigging factor for hail episodes at Craiova was larger (54% compared to that of dynamic convection. There are also presented the synoptic and mesoscale conditions which generated this phenomenon in two distinct cases: one generated by thermal convection, observed in 8 June 2013, and the other by dynamic convection, occurred in 14 April 2012. The synoptic and mesoscale conditions during the day of 8 June 2013 favored the occurrence of hail Craiova station due to the weak synoptic forcing and to a relatively warm and wet boundary layer, thus meeting two of the conditions of mass instability. In the second case, the baric configuration at sea level, presenting a low in the west-central basin of Mediterranean, was supported in the middle troposphere, at the 500hPa level, by the presence of a trough extending over most of the Europe, up to the south. The hail was generated, in this case, by the occluded front associated with the Mediterranean depression.

  12. Predicting effects of global warming on growth and mortality of upland oak species in the midwestern United States: A physiologically based dendroecological approach

    Energy Technology Data Exchange (ETDEWEB)

    LeBlanc, D.C. (Ball State Univ., Muncie, IN (United States)); Foster, J.R. (Butler Univ., Indianapolis, IN (United States))

    1992-01-01

    An ecophysiological model and dendroecological analyses were combined to evaluate potential effects of global warming on the physiology, growth, and mortality of white oak (Quercus alba L.) and black oak (Quercus velutina Lam.) in the Ohio River region. The model integrated data for ecophysiology of oak species, site attributes, and daily temperature and precipitation to model nonlinear responses of stomatal conductance (g), net photosynthesis (P) and woody respiration (R) to variations in temperature and soil water content. Relationships between modeled physiological response indices and actual annual radial growth indices were evaluated by regression analyses, using growth and weather data for 1900-1987. Modeled physiological response indices explained 40-60% of variation in radial growth indices. To evaluate the effects of global warming, daily temperature values for 1900-1987 were increased by 2 or 5[degree]C, without changing precipitation values, and physiological response indices were computed. Model indices generated in warming simulations were entered into dendroclimatic regression models calibrated under conditions without any warming to predict radial growth under warming scenarios. Under the warming scenarios, the model predicted a substantial increase in growing season R, but little change in growing season P. The net effect of increased R with little change in P was a reduction in radial growth and a higher frequency of years with climatic conditions stressful to oaks on upland sites. A historical association between severe drought and increased incidence of oak growth decline and mortality indicated that global warming could increase the incidence of decline and mortality in oak populations on upland sites similar to those in this study. 63 refs., 6 figs., 4 tabs.

  13. Establishment of warm season grasses with and without the use of compost soil amendments

    Science.gov (United States)

    Perry, M.C.; Osenton, P.C.; Gough, G.A.; Lohnes, E.J.R.

    2000-01-01

    Two compost materials (COMPRO and LEAFGRO) were evaluated as soil amendments to enhance wildlife habitats, while maintaining optimal floral and faunal biodiversity. Special emphasis was placed on the role of compost in the establishment and retention of native warm season grasses (Andropogon gerardi, Schizachyrium scoparium, and Sorghastrum nutans). This study was conducted at two sites that were degraded by previous military and farming operations. Sites were plowed twice in 1996 and then a one inch layer of COMPRO or LEAFGRO was applied with a modified manure spreader and disked into the soil to a depth of 3 inches. Vegetation sampling was conducted in 1996, 1997, 1998, and 1999. Initially the greatest vegetation cover occurred in plots treated with LEAFGRO. Plots treated with COMPRO had less vegetation cover than both types of controls plots (with and without warmseason grasses). The reduced plant growth in the plots treated with COMPRO may have been related to the much higher soil pH of these plots on both sites. In subsequent years, amounts of warm season grasses increased, however, in general there was more cover of warm season grasses in plots that did not receive compost than those that did receive compost. Sorghastrum nutans was more abundant on the sites than either of the other two species of warm season grasses. Invertebrate and mammal data collected for three years indicated that there was not more faunal activity in the plots treated with LEAFGRO or COMPRO compost soil amendments. Results indicate that compost amendments did not improve establishment of warm season grasses and the resultant faunal diversity or abundance.

  14. Seasonal Variation in Mortality, Medical Care Expenditure and Institutionalization in Older People

    DEFF Research Database (Denmark)

    Rolden, Herbert Jan Albert; Rohling, Jos Hermanus Theodoor; van Bodegom, David

    2015-01-01

    BACKGROUND: The mortality rates of older people changes with the seasons. However, it has not been properly investigated whether the seasons affect medical care expenditure (MCE) and institutionalization. Seasonal variation in MCE is plausible, as MCE rises exponentially before death. It is there......BACKGROUND: The mortality rates of older people changes with the seasons. However, it has not been properly investigated whether the seasons affect medical care expenditure (MCE) and institutionalization. Seasonal variation in MCE is plausible, as MCE rises exponentially before death...

  15. Seasonal Variability May Affect Microbial Decomposers and Leaf Decomposition More Than Warming in Streams.

    Science.gov (United States)

    Duarte, Sofia; Cássio, Fernanda; Ferreira, Verónica; Canhoto, Cristina; Pascoal, Cláudia

    2016-08-01

    Ongoing climate change is expected to affect the diversity and activity of aquatic microbes, which play a key role in plant litter decomposition in forest streams. We used a before-after control-impact (BACI) design to study the effects of warming on a forest stream reach. The stream reach was divided by a longitudinal barrier, and during 1 year (ambient year) both stream halves were at ambient temperature, while in the second year (warmed year) the temperature in one stream half was increased by ca. 3 °C above ambient temperature (experimental half). Fine-mesh bags containing oak (Quercus robur L.) leaves were immersed in both stream halves for up to 60 days in spring and autumn of the ambient and warmed years. We assessed leaf-associated microbial diversity by denaturing gradient gel electrophoresis and identification of fungal conidial morphotypes and microbial activity by quantifying leaf mass loss and productivity of fungi and bacteria. In the ambient year, no differences were found in leaf decomposition rates and microbial productivities either between seasons or stream halves. In the warmed year, phosphorus concentration in the stream water, leaf decomposition rates, and productivity of bacteria were higher in spring than in autumn. They did not differ between stream halves, except for leaf decomposition, which was higher in the experimental half in spring. Fungal and bacterial communities differed between seasons in both years. Seasonal changes in stream water variables had a greater impact on the activity and diversity of microbial decomposers than a warming regime simulating a predicted global warming scenario.

  16. The impact of global warming on seasonality of ocean primary production

    Directory of Open Access Journals (Sweden)

    S. Henson

    2013-06-01

    Full Text Available The seasonal cycle (i.e. phenology of oceanic primary production (PP is expected to change in response to climate warming. Here, we use output from 6 global biogeochemical models to examine the response in the seasonal amplitude of PP and timing of peak PP to the IPCC AR5 warming scenario. We also investigate whether trends in PP phenology may be more rapidly detectable than trends in annual mean PP. The seasonal amplitude of PP decreases by an average of 1–2% per year by 2100 in most biomes, with the exception of the Arctic which sees an increase of ~1% per year. This is accompanied by an advance in the timing of peak PP by ~0.5–1 months by 2100 over much of the globe, and particularly pronounced in the Arctic. These changes are driven by an increase in seasonal amplitude of sea surface temperature (where the maxima get hotter faster than the minima and a decrease in the seasonal amplitude of the mixed layer depth and surface nitrate concentration. Our results indicate a transformation of currently strongly seasonal (bloom forming regions, typically found at high latitudes, into weakly seasonal (non-bloom regions, characteristic of contemporary subtropical conditions. On average, 36 yr of data are needed to detect a climate-change-driven trend in the seasonal amplitude of PP, compared to 32 yr for mean annual PP. Monthly resolution model output is found to be inadequate for resolving phenological changes. We conclude that analysis of phytoplankton seasonality is not necessarily a shortcut to detecting climate change impacts on ocean productivity.

  17. Photosynthetic enhancement by elevated CO₂ depends on seasonal temperatures for warmed and non-warmed Eucalyptus globulus trees.

    Science.gov (United States)

    Quentin, A G; Crous, K Y; Barton, C V M; Ellsworth, D S

    2015-11-01

    Arguments based on the biochemistry of photosynthesis predict a positive interaction between elevated atmospheric [CO2] and temperature on photosynthesis as well as growth. In contrast, few long-term studies on trees find greater stimulation of photosynthesis in response to elevated [CO2] at warmer compared with cooler temperatures. To test for CO2 × temperature interactions on leaf photosynthesis and whole-plant growth, we planted Eucalyptus globulus Labill. in climate-controlled chambers in the field at the Hawkesbury Forest Experiment research site, and investigated how photosynthetic enhancement changed across a range of seasonal temperatures. Trees were grown in a complete two-way factorial design with two CO2 concentrations (ambient and ambient + 240 ppm) and two temperatures (ambient and ambient + 3 °C) for 15 months until they reached ∼10 m height, after which they were harvested for biomass. There was significant enhancement of photosynthesis and growth with elevated [CO2], with the photosynthetic stimulation varying with season, but there was no significant effect of warming. Photosynthetic enhancement was higher in summer (+46% at 28 °C) than in winter (+14% at 20 °C). Photosynthetic enhancement as a function of leaf temperature was consistent with theoretical expectations, but was strongly mediated by the intercellular [CO2]/ambient [CO2] (Ci/Ca) ratio across seasons. Total tree biomass after 15 months was 66% larger in elevated CO2 (P = 0.017) with no significant warming effect detected. The fraction of biomass in coarse roots was reduced in warmed trees compared with ambient temperature controls, but there was no evidence of changed biomass allocation patterns in elevated CO2. We conclude that there are strong and consistent elevated CO2 effects on photosynthesis and biomass of E. globulus. It is crucial to consider stomatal conductance under a range of conditions to appraise the interactive effect of [CO2] and temperature on

  18. The impact of global warming on seasonality of ocean primary production

    Directory of Open Access Journals (Sweden)

    S. Henson

    2013-01-01

    Full Text Available The seasonal cycle (i.e. phenology of oceanic primary production (PP is expected to change in response to climate warming. Here, we use output from 6 global biogeochemical models to examine the response in the seasonal amplitude of PP and timing of peak PP to the IPCC AR5 warming scenario. We also investigate whether trends in PP phenology may be more rapidly detectable than trends in PP itself. The seasonal amplitude of PP decreases by an average of 1–2% per year by 2100 in most biomes, with the exception of the Arctic which sees an increase of ~1% per year. This is accompanied by an advance in the timing of peak PP by ~0.5–1 months by 2100 over much of the globe, and particularly pronounced in the Arctic. These changes are driven by an increase in seasonal amplitude of sea surface temperature (where the maxima get hotter faster than the minima and a decrease in the seasonal amplitude of the mixed layer depth and surface nitrate concentration. Our results indicate a transformation of currently strongly seasonal (bloom forming regions, typically found at high latitudes, into weakly seasonal (non-bloom regions, characteristic of contemporary subtropical conditions. On average, 36 yr of data are needed to detect a climate change-driven trend in the seasonal amplitude of PP, compared to 32 yr for mean annual PP. We conclude that analysis of phytoplankton phenology is not necessarily a shortcut to detecting climate change impacts on ocean productivity.

  19. Cold season soil respiration in response to grazing and warming in the High Arctic Svalbard

    DEFF Research Database (Denmark)

    Strebel, Ditte; Elberling, Bo; Morgner, Elke;

    2010-01-01

    ) and solid-state 13C nuclear magnetic resonance (NMR) spectroscopy. Results reveal variations in soil carbon cycling, with significant seasonal trends controlled by temperature, water content and snow. Experimental warming (OTCs) increased near-surface temperatures in the growing season, resulting......The influence of goose grazing intensity and open-topped chambers (OTCs) on near-surface quantities and qualities of soil organic carbon (SOC) was evaluated in wet and mesic ecosystems in Svalbard. This study followed up a field experiment carried out in 2003-05 (part of the project Fragility...

  20. An Update to the Warm-Season Convective Wind Climatology of KSC/CCAFS

    Science.gov (United States)

    Lupo, Kevin

    2012-01-01

    Total of 1100 convective events in the 17-year warm-season climatology at KSC/CCAFS. July and August typically are the peak of convective events, May being the minimum. Warning and non-warning level convective winds are more likely to occur in the late afternoon (1900-2000Z). Southwesterly flow regimes and wind directions produce the strongest winds. Storms moving from southwesterly direction tend to produce more warning level winds than those moving from the northerly and easterly directions.

  1. Chronic environmental stress enhances tolerance to seasonal gradual warming in marine mussels

    Science.gov (United States)

    Múgica, Maria; Izagirre, Urtzi; Sokolova, Inna M.

    2017-01-01

    In global climate change scenarios, seawater warming acts in concert with multiple stress sources, which may enhance the susceptibility of marine biota to thermal stress. Here, the responsiveness to seasonal gradual warming was investigated in temperate mussels from a chronically stressed population in comparison with a healthy one. Stressed and healthy mussels were subjected to gradual temperature elevation for 8 days (1°C per day; fall: 16–24°C, winter: 12–20°C, summer: 20–28°C) and kept at elevated temperature for 3 weeks. Healthy mussels experienced thermal stress and entered the time-limited survival period in the fall, became acclimated in winter and exhibited sublethal damage in summer. In stressed mussels, thermal stress and subsequent health deterioration were elicited in the fall but no transition into the critical period of time-limited survival was observed. Stressed mussels did not become acclimated to 20°C in winter, when they experienced low-to-moderate thermal stress, and did not experience sublethal damage at 28°C in summer, showing instead signs of metabolic rate depression. Overall, although the thermal threshold was lowered in chronically stressed mussels, they exhibited enhanced tolerance to seasonal gradual warming, especially in summer. These results challenge current assumptions on the susceptibility of marine biota to the interactive effects of seawater warming and pollution. PMID:28333994

  2. On the origin of the Tsushima Warm Current and its seasonality

    Science.gov (United States)

    Isobe, Atsuhiko

    1999-01-01

    There are two different schools of thought with regard to the origin of the Tsushima Warm Current. One school of thought believes that it comes from the Taiwan Strait, while the other believes that it enters the East China Sea from the Kuroshio region southwest of Kyushu, Japan, crossing the steep shelf slope. Using the seasonally averaged distributions of the wind (30-year mean of Comprehensive Ocean Atmosphere Data Set) and density (data from 1961 to 1990 supplied by Japan Oceanographic Data Center) in the East China and Yellow Seas, we determine the volume transport distribution diagnostically through a numerical model in which we solve the vorticity equation of the vertically averaged flow. Then, we try to identify the origin of the volume transport of the Tsushima Warm Current and its seasonality. The results except for the autumn indicate the existence of the so-called Taiwan-Tsushima Warm Current System (Fang et al., 1991), i.e. a continuity of the volume transport between the Taiwan and Tsushima/Korea Straits. However, this current system breaks down in the autumn. According to this study, about 66% of the volume transport of the Tsushima Warm Current comes directly from the Kuroshio region in autumn, crossing the shelf edge of the East China Sea.

  3. Observed changes in seasonal heat waves and warm temperature extremes in the Romanian Carpathians

    Science.gov (United States)

    Micu, Dana; Birsan, Marius-Victor; Dumitrescu, Alexandru; Cheval, Sorin

    2015-04-01

    Extreme high temperature have a large impact on environment and human activities, especially in high elevation areas particularly sensitive to the recent climate warming. The climate of the Romanian Carpathians became warmer particularly in winter, spring and summer, exibiting a significant increasing frequency of warm extremes. The paper investigates the seasonal changes in the frequency, duration and intensity of heat waves in relation to the shifts in the daily distribution of maximum temperatures over a 50-year period of meteorological observations (1961-2010). The paper uses the heat wave definition recommended by the Expert Team on Climate Change Detection and Indices (ETCCDI) and exploits the gridded daily dataset of maximum temperature at 0.1° resolution (~10 km) developed in the framework of the CarpatClim project (www.carpatclim.eu). The seasonal changes in heat waves behavior were identified using the Mann-Kendall non-parametric trend test. The results suggest an increase in heat wave frequency and a lengthening of intervals affected by warm temperature extremes all over the study region, which are explained by the shifts in the upper (extreme) tail of the daily maximum temperature distribution in most seasons. The trends are consistent across the region and are well correlated to the positive phases of the East Atlantic Oscillation. Our results are in good agreement with the previous temperature-related studies concerning the Carpathian region. This study was realized within the framework of the project GENCLIM, financed by UEFISCDI, code PN-II 151/2014.

  4. THE STUDY OF THE YELLOW SEA WARM CURRENT AND ITS SEASONAL VARIABILITY

    Institute of Scientific and Technical Information of China (English)

    XU Ling-ling; WU De-xing; LIN Xiao-pei; MA Chao

    2009-01-01

    The Yellow Sea Warm Current (YSWC) penetrates northward along the Yellow Sea Trough, and brings warm and saline water towards the Bohai Sea. The YSWC becomes much less intrusive in summer and is limited mostly in the southern trough, contrasting with a deep winter penetration well into the trough. The seasonal variability of the YSWC has prompted a debate regarding which controls the YSWC and its seasonal variability. In this article, the annual mean and seasonal variability of the YSWC was examined by using a 3-D ocean model together with several experiments. The results show that in the annual mean the YSWC is a compensating current firstly for the southward Korea Coastal Current (KCC), which is mainly caused by the Kuroshio Current (KC). The local wind-stress forcing plays an important but secondary role. However, the local monsoonal forcing plays a prominent role in modulating the seasonal variability. A deep northwestward intrusion of the YSWC in winter, for instance, is mainly due to a robustly developed China Coastal Current (CCC) which draws water along the Yellow Sea trough to feed a southward flow all the way from the Bohai Sea to the Taiwan Strait.

  5. Intake, digestibility, and nitrogen retention by sheep supplemented with warm-season legume haylages or soybean meal

    National Research Council Canada - National Science Library

    Foster, J. L; Adesogan, A. T; Carter, J. N; Blount, A. R; Myer, R. O; Phatak, S. C

    2009-01-01

    .... This study determined how supplementing bahiagrass haylage ( Paspalum notatum Flügge cv. Tifton 9) with soybean [ Glycine max (L.) Merr.] meal or warm-season legume haylages affected the performance of lambs...

  6. Global warming-enhanced stratification and mass mortality events in the Mediterranean

    Science.gov (United States)

    Coma, Rafel; Ribes, Marta; Serrano, Eduard; Jiménez, Eroteida; Salat, Jordi; Pascual, Josep

    2009-01-01

    Summer conditions in the Mediterranean Sea are characterized by high temperatures and low food availability. This leads to “summer dormancy” in many benthic suspension feeders due to energetic constraints. Analysis of the most recent 33-year temperature time series demonstrated enhanced stratification due to global warming, which produced a ≈40% lengthening of summer conditions. Many biological processes are expected to be affected by this trend, culminating in such events as mass mortality of invertebrates. Climatic anomalies concomitant with the occurrence of these events represent prolonged exposure to warmer summer conditions coupled with reduced food resources. Simulation of the effects of these conditions on a model organism demonstrated a biomass loss of >35%. Losses of this magnitude result in mortality similar to that noted in field observations during mass mortality events. These results indicate that temperature anomalies are the underlying cause of the events, with energetic constraints serving as the main triggering mechanism. PMID:19332777

  7. Incorporating residual temperature and specific humidity in predicting weather-dependent warm-season electricity consumption

    Science.gov (United States)

    Guan, Huade; Beecham, Simon; Xu, Hanqiu; Ingleton, Greg

    2017-02-01

    Climate warming and increasing variability challenges the electricity supply in warm seasons. A good quantitative representation of the relationship between warm-season electricity consumption and weather condition provides necessary information for long-term electricity planning and short-term electricity management. In this study, an extended version of cooling degree days (ECDD) is proposed for better characterisation of this relationship. The ECDD includes temperature, residual temperature and specific humidity effects. The residual temperature is introduced for the first time to reflect the building thermal inertia effect on electricity consumption. The study is based on the electricity consumption data of four multiple-street city blocks and three office buildings. It is found that the residual temperature effect is about 20% of the current-day temperature effect at the block scale, and increases with a large variation at the building scale. Investigation of this residual temperature effect provides insight to the influence of building designs and structures on electricity consumption. The specific humidity effect appears to be more important at the building scale than at the block scale. A building with high energy performance does not necessarily have low specific humidity dependence. The new ECDD better reflects the weather dependence of electricity consumption than the conventional CDD method.

  8. Seasonality and cyclic tendency of mortality in a Pyrenean population

    Directory of Open Access Journals (Sweden)

    González-Martín, A.

    1990-06-01

    Full Text Available Mortality characteristics exert a great influence on the demographic framework of the population, determined by different factors: internal (genetical and cultural specific features, external (dependent on the ecosystem, and Intermediate ones (the population's capacity to adapt itself to the environment. The analysis of seasonal distribution of 3313 deaths recorded at Parish Registers from El Pont de Suert (Alta Ribagorça, Catalonia, Spain from 1664, is evidence of the importance of all these factors. The distribution patterns show the relationship between mortality and climatic conditions, epidemiological conditions, as well as socio-economical and demographical transformations. The cyclical trend model, common to many Iberian mountain populations, does not show up In this particular population.

    [es] Las características de la mortalidad Influyen decisivamente en la estructura demográfica de las poblaciones, regida por diferentes factores: internos (rasgos específicos genéticos y culturales, externos (características del ecosistema e intermedios (capacidad de la población de autoajustarse al ambiente. El estudio de la distribución estacional de las 3313 defunciones registradas en la Villa de El Pont de Suert (Alta Ribagorça, Cataluña desde 1664 evidencia la importancia de todos estos factores. Los patrones de distribución muestran el Influjo de las condiciones climáticas, de los ambientes epidemiológicos, así como de las transformaciones socioeconómicas y demográficas. El modelo de tendencia cíclica en la mortalidad, común a muchas poblaciones ibéricas de montaña, no se evidencia en esta población.
    [fr] Les caractéristiques de la mortalité influent sur la structure démographique des populations, qui est, à son tour, déterminée par différents facteurs: internes (traits génétiques et culturelles spécifiques, externes (caractéristiques de l'écosystème et intermédiaires (capacité de la population

  9. Vulnerability to the mortality effects of warm temperature in the districts of England and Wales

    Science.gov (United States)

    Bennett, James E.; Blangiardo, Marta; Fecht, Daniela; Elliott, Paul; Ezzati, Majid

    2014-04-01

    Warm temperatures adversely affect disease occurrence and death, in extreme conditions as well as when the temperature changes are more modest. Therefore climate change, which is expected to affect both average temperatures and temperature variability, is likely to impact health even in temperate climates. Climate change risk assessment is enriched if there is information on vulnerability and resilience to effects of temperature. Some studies have analysed socio-demographic characteristics that make individuals vulnerable to adverse effects of temperature. Less is known about community-level vulnerability. We used geo-coded mortality and environmental data and Bayesian spatial methods to conduct a national small-area analysis of the mortality effects of warm temperature for all 376 districts in England and Wales. In the most vulnerable districts, those in London and south/southeast England, odds of dying from cardiorespiratory causes increased by more than 10% for 1 °C warmer temperature, compared with virtually no effect in the most resilient districts, which were in the far north. A 2 °C warmer summer may result in 1,552 (95% credible interval 1,307-1,762) additional deaths, about one-half of which would occur in 95 districts. The findings enable risk and adaptation analyses to incorporate local vulnerability to warm temperature and to quantify inequality in its effects.

  10. Magnitude and pattern of Arctic warming governed by the seasonality of radiative forcing

    Science.gov (United States)

    Bintanja, R.; Krikken, F.

    2016-12-01

    Observed and projected climate warming is strongest in the Arctic regions, peaking in autumn/winter. Attempts to explain this feature have focused primarily on identifying the associated climate feedbacks, particularly the ice-albedo and lapse-rate feedbacks. Here we use a state-of-the-art global climate model in idealized seasonal forcing simulations to show that Arctic warming (especially in winter) and sea ice decline are particularly sensitive to radiative forcing in spring, during which the energy is effectively ‘absorbed’ by the ocean (through sea ice melt and ocean warming, amplified by the ice-albedo feedback) and consequently released to the lower atmosphere in autumn and winter, mainly along the sea ice periphery. In contrast, winter radiative forcing causes a more uniform response centered over the Arctic Ocean. This finding suggests that intermodel differences in simulated Arctic (winter) warming can to a considerable degree be attributed to model uncertainties in Arctic radiative fluxes, which peak in summer.

  11. [On the increase in mortality in Italy in 2015: analysis of seasonal mortality in the 32 municipalities included in the Surveillance system of daily mortality].

    Science.gov (United States)

    Michelozzi, Paola; De' Donato, Francesca; Scortichini, Matteo; De Sario, Manuela; Asta, Federica; Agabiti, Nera; Guerra, Ranieri; de Martino, Annamaria; Davoli, Marina

    2016-01-01

    the Italian National Institute of Statistics (Istat) estimated an increase in mortality in Italy of 11.3% between January and August 2015 compared to the previous year. During summer 2015, an excess in mortality, attributed to heat waves, was observed. to estimate the excess mortality in 2015 using data from the rapid mortality surveillance system (SiSMG) operational in 32 Italian cities. time series models were used to estimate the excess in mortality among the elderly (65+ years) in 2015 by season (winter and summer). Excess mortality was defined as the difference between observed daily and expected (baseline) mortality for the five previous years (2009- 2013); seasonal mortality in 2015 was compared with mortality observed in 2012, 2013, and 2014. An analysis by cause of death (cardiovascular and respiratory), gender, and age group was carried out in Rome. data confirm an overall estimated excess in mortality of +11% in 2015. Seasonal analysis shows a greater excess in winter (+13%) compared to the summer period (+10%). The excess in winter deaths seems to be attributable to the peak in influenza rather than to low temperatures. Summer excess mortality was attributed to the heat waves of July and August 2015. The lower mortality registered in Italy during summer 2014 (-5.9%) may have contributed to the greater excess registered in 2015. In Rome, cause-specific analysis showed a higher excess among the very old (85+ years) mainly for cardiovascular and respiratory causes in winter. In summer, the excess was observed among both the elderly and in the adult population (35-64 years). results suggest the need for a more timely use of mortality data to evaluate the impact of different risk factors. Public health measures targeted to susceptible subgroups should be enhanced (e.g., Heat Prevention Plans, flu vaccination campaigns).

  12. Biomass and fibre productivity evaluation of novel native warm season grasses

    Energy Technology Data Exchange (ETDEWEB)

    Jefferson, P.G. [Agriculture and Agri-Food Canada, Swift Current, SK (Canada); McElroy, A.R. [Agriculture Canada, Ottawa, ON (Canada). Grain and Oilseeds Branch; McCaughey, P. [Agriculture and Agri-Food Canada Research Centre, Brandon, MB (Canada)

    1997-07-01

    Biomass production and cellulose content of a range of switchgrass (Panicum virgatum L.) cultivars was discussed. In 1991 the U.S. Department of Energy identified switchgrass, a native warm-season grass, as the model biomass crop for ethanol production from lignocellulosic materials. A Canadian study was conducted in which 11 cultivars of switchgrass were seeded at small plots of dryland and irrigated sites in Manitoba and Saskatchewan. No switchgrass plants established themselves at the dryland site at Swift Current Saskatchewan. Biomass was determined by clipping above-ground biomass in September 1994 and 1996. Dry matter content and cellulose content was determined. Results showed that the biomass production of the cultivar Dacotah was less than cool-season grasses at test sites in Manitoba, and Saskatchewan. The high yields observed for cultivars adapted to southern or eastern regions were not sustainable in the semiarid prairie region of Canada. 8 refs., 2 tabs.

  13. Coupled prediction of flood response and debris flow initiation during warm and cold season events in the Southern Appalachians, USA

    OpenAIRE

    Tao, J.; A. P. Barros

    2013-01-01

    Debris flows associated with rainstorms are a frequent and devastating hazard in the Southern Appalachians in the United States. Whereas warm season events are clearly associated with heavy rainfall intensity, the same cannot be said for the cold season events. Instead, there is a relationship between large (cumulative) rainfall events independently of season, and thus hydrometeorological regime, and debris flows. This suggests that the dynamics of subsurface hydrologic processes play an impo...

  14. Invasive warm-season grasses reduce mycorrhizal root colonization and biomass production of native prairie grasses.

    Science.gov (United States)

    Wilson, Gail W T; Hickman, Karen R; Williamson, Melinda M

    2012-07-01

    Soil organisms play important roles in regulating ecosystem-level processes and the association of arbuscular mycorrhizal (AM) fungi with a plant species can be a central force shaping plant species' ecology. Understanding how mycorrhizal associations are affected by plant invasions may be a critical aspect of the conservation and restoration of native ecosystems. We examined the competitive ability of old world bluestem, a non-native grass (Caucasian bluestem [Bothriochloa bladhii]), and the influence of B. bladhii competition on AM root colonization of native warm-season prairie grasses (Andropogon gerardii or Schizachyrium scoparium), using a substitutive design greenhouse competition experiment. Competition by the non-native resulted in significantly reduced biomass production and AM colonization of the native grasses. To assess plant-soil feedbacks of B. bladhii and Bothriochloa ischaemum, we conducted a second greenhouse study which examined soil alterations indirectly by assessing biomass production and AM colonization of native warm-season grasses planted into soil collected beneath Bothriochloa spp. This study was conducted using soil from four replicate prairie sites throughout Kansas and Oklahoma, USA. Our results indicate that a major mechanism in plant growth suppression following invasion by Bothriochloa spp. is the alteration in soil microbial communities. Plant growth was tightly correlated with AM root colonization demonstrating that mycorrhizae play an important role in the invasion of these systems by Bothriochloa spp. and indicating that the restoration of native AM fungal communities may be a fundamental consideration for the successful establishment of native grasses into invaded sites.

  15. Disruption of the European climate seasonal clock in a warming world

    Science.gov (United States)

    Cattiaux, J.; Cassou, C.

    2015-12-01

    Strength and inland penetration of the oceanic westerly flow over Europe control a large part of the temperature variability over most of the continent. Reduced westerlies, linked to high-pressure anomalies over Scandinavia, induce cold conditions in winter and warm conditions in summer. Here we propose to define the onset of these two seasons as the calendar day where the daily circulation/temperature relationship over Western Europe switches sign. According to this meteorologically-based metrics assessed from several observational datasets, we provide robust evidence for an earlier summer onset by ~10 days between the 1960s and 2000s. Results from model ensemble simulations dedicated to detection-attribution show that this calendar advance is incompatible with the sole internal climate variability and can be attributed to anthropogenic forcings. Late winter snow disappearance over Eastern Europe affects cold air intrusion to the West when easterlies blow, and is mainly responsible for the observed present-day and near-future summer advance. Our findings agree with phenological-based trends (earlier spring events) reported for many living species over Europe, for which they provide a novel dynamical interpretation beyond the traditionally evoked global warming effect. Based on business-as-usual scenario, a seasonal shift of ~25 days is expected by 2100 for summer onset, while no clear signal arises for winter onset.

  16. Establishment of warm-season native grasses and forbs on drastically disturbed lands

    Energy Technology Data Exchange (ETDEWEB)

    Miller, S. [Missouri Dept. of Natural Resources, Jefferson City, MO (United States)

    1998-12-31

    Establishment of warm-season native grasses and forbs (WSNGs) has been viewed by landowners, agronomists, natural resource managers and reclamation specialists as being too expensive and difficult, especially for reclamation, which requires early stand closure and erosion control. Natural resource managers have learned a great deal about establishing WSNGs since the implementation of the 1985 Farm Bill`s Conservation Reserve Program (CRP). Reclamation specialists must begin to use this information to improve reclamation success. Quality control of seed equipment and planting methods has been proven to be the crucial first step in successful establishment. Seedling germination, growth and development of WSNGs are different from that of introduced cool-season grasses and legumes. Specialized seed drills and spring planting periods are essential. Because shoot growth lags far behind root growth the first two seasons, WSNGs often are rejected for reclamation use. Usually, the rejection is based on preconceived notions that bare ground will erode and on reclamation specialists` desire for a closed, uniform, grassy lawn. WSNG`s extensive root systems inhibit rill and gully erosion by the fall of the first season. Planting a weakly competitive, short-lived nurse crop such as perennial ryegrass (Lolium perenne) at low rates with the WSNG mixture can reduce first-season sheet and rill erosion problems and give an appearance of a closed stand. Benefits of WSNGs in soil building and their acid-tolerance make them ideal species for reclamation of drastically disturbed lands. WSNGs and forbs enhance wildlife habitat and promote natural succession and the invasion of the reclamation site by other native species, particularly hardwood trees, increasing diversity and integrating the site into the local ecosystem. This is perhaps their most important attribute. Most alien grasses and legumes inhibit natural succession, slowing the development of a stable mine soil ecosystem. This

  17. Trait Acclimation Mitigates Mortality Risks of Tropical Canopy Trees under Global Warming.

    Science.gov (United States)

    Sterck, Frank; Anten, Niels P R; Schieving, Feike; Zuidema, Pieter A

    2016-01-01

    There is a heated debate about the effect of global change on tropical forests. Many scientists predict large-scale tree mortality while others point to mitigating roles of CO2 fertilization and - the notoriously unknown - physiological trait acclimation of trees. In this opinion article we provided a first quantification of the potential of trait acclimation to mitigate the negative effects of warming on tropical canopy tree growth and survival. We applied a physiological tree growth model that incorporates trait acclimation through an optimization approach. Our model estimated the maximum effect of acclimation when trees optimize traits that are strongly plastic on a week to annual time scale (leaf photosynthetic capacity, total leaf area, stem sapwood area) to maximize carbon gain. We simulated tree carbon gain for temperatures (25-35°C) and ambient CO2 concentrations (390-800 ppm) predicted for the 21st century. Full trait acclimation increased simulated carbon gain by up to 10-20% and the maximum tolerated temperature by up to 2°C, thus reducing risks of tree death under predicted warming. Functional trait acclimation may thus increase the resilience of tropical trees to warming, but cannot prevent tree death during extremely hot and dry years at current CO2 levels. We call for incorporating trait acclimation in field and experimental studies of plant functional traits, and in models that predict responses of tropical forests to climate change.

  18. Trait acclimation mitigates mortality risks of tropical canopy trees under global warming

    Directory of Open Access Journals (Sweden)

    Frank eSterck

    2016-05-01

    Full Text Available There is a heated debate about the effect of global change on tropical forests. Many scientists predict large-scale tree mortality while others point to mitigating roles of CO2 fertilization and – the notoriously unknown – physiological trait acclimation of trees. In this opinion article we provided a first quantification of the potential of trait acclimation to mitigate the negative effects of warming on tropical canopy tree growth and survival. We applied a physiological tree growth model that incorporates trait acclimation through an optimization approach. Our model estimated the maximum effect of acclimation when trees optimize traits that are strongly plastic on a week to annual time scale (leaf photosynthetic capacity, total leaf area, stem sapwood area to maximize carbon gain. We simulated tree carbon gain for temperatures (25-35ºC and ambient CO2 concentrations (390-800 ppm predicted for the 21st century. Full trait acclimation increased simulated carbon gain by up to 10-20% and the maximum tolerated temperature by up to 2ºC, thus reducing risks of tree death under predicted warming. Functional trait acclimation may thus increase the resilience of tropical trees to warming, but cannot prevent tree death during extremely hot and dry years at current CO2 levels. We call for incorporating trait acclimation in field and experimental studies of plant functional traits, and in models that predict responses of tropical forests to climate change.

  19. INTERACTIONS BETWEEN OCEAN ACIDIFICATION AND WARMING ON THE MORTALITY AND DISSOLUTION OF CORALLINE ALGAE(1).

    Science.gov (United States)

    Diaz-Pulido, Guillermo; Anthony, Kenneth R N; Kline, David I; Dove, Sophie; Hoegh-Guldberg, Ove

    2012-02-01

    Coralline algae are among the most sensitive calcifying organisms to ocean acidification as a result of increased atmospheric carbon dioxide (pCO2 ). Little is known, however, about the combined impacts of increased pCO2 , ocean acidification, and sea surface temperature on tissue mortality and skeletal dissolution of coralline algae. To address this issue, we conducted factorial manipulative experiments of elevated CO2 and temperature and examined the consequences on tissue survival and skeletal dissolution of the crustose coralline alga (CCA) Porolithon (=Hydrolithon) onkodes (Heydr.) Foslie (Corallinaceae, Rhodophyta) on the southern Great Barrier Reef (GBR), Australia. We observed that warming amplified the negative effects of high pCO2 on the health of the algae: rates of advanced partial mortality of CCA increased from ocean acidification under warm conditions, suggesting that previous experiments focused on ocean acidification alone have underestimated the impact of future conditions on coralline algae. Given the central role that coralline algae play within coral reefs, these conclusions have serious ramifications for the integrity of coral-reef ecosystems.

  20. A Digital Map From External Forcing to the Final Surface Warming Pattern and its Seasonal Cycle

    Science.gov (United States)

    Cai, M.

    2015-12-01

    Historically, only the thermodynamic processes (e.g., water vapor, cloud, surface albedo, and atmospheric lapse rate) that directly influence the top of the atmosphere (TOA) radiative energy flux balance are considered in climate feedback analysis. One of my recent research areas is to develop a new framework for climate feedback analysis that explicitly takes into consideration not only the thermodynamic processes that the directly influence the TOA radiative energy flux balance but also the local dynamical (e.g., evaporation, surface sensible heat flux, vertical convections etc) and non-local dynamical (large-scale horizontal energy transport) processes in aiming to explain the warming asymmetry between high and low latitudes, between ocean and land, and between the surface and atmosphere. In the last 5-6 years, we have developed a coupled atmosphere-surface climate feedback-response analysis method (CFRAM) as a new framework for estimating climate feedback and sensitivity in coupled general circulation models with a full physical parameterization package. In the CFRAM, the isolation of partial temperature changes due to an external forcing alone or an individual feedback is achieved by solving the linearized infrared radiation transfer model subject to individual energy flux perturbations (external or due to feedbacks). The partial temperature changes are addable and their sum is equal to the (total) temperature change (in the linear sense). The CFRAM is used to isolate the partial temperature changes due to the external forcing, due to water vapor feedback, clouds, surface albedo, local vertical convection, and non-local atmospheric dynamical feedbacks, as well as oceanic heat storage. It has been shown that seasonal variations in the cloud feedback, surface albedo feedback, and ocean heat storage/dynamics feedback, directly caused by the strong annual cycle of insolation, contribute primarily to the large seasonal variation of polar warming. Furthermore, the

  1. Climate Warming and Seasonal Precipitation Change Interact to Limit Species Distribution Shifts across Western North America.

    Science.gov (United States)

    Harsch, Melanie A; HilleRisLambers, Janneke

    2016-01-01

    Using an extensive network of occurrence records for 293 plant species collected over the past 40 years across a climatically diverse geographic section of western North America, we find that plant species distributions were just as likely to shift upwards (i.e., towards higher elevations) as downward (i.e., towards lower elevations)-despite consistent warming across the study area. Although there was no clear directional response to climate warming across the entire study area, there was significant region- to region- variation in responses (i.e. from as many as 73% to as few as 32% of species shifting upward). To understand the factors that might be controlling region-specific distributional shifts of plant species, we explored the relationship between the direction of change in distribution limits and the nature of recent climate change. We found that the direction that distribution limits shifted was explained by an interaction between the rate of change in local summer temperatures and seasonal precipitation. Specifically, species were more likely to shift upward at their upper elevational limit when minimum temperatures increased and snowfall was unchanging or declined at slower rates (<0.5 mm/year). This suggests that both low temperature and water availability limit upward shifts at upper elevation limits. By contrast, species were more likely to shift upwards at their lower elevation limit when maximum temperatures increased, but also shifted upwards under conditions of cooling temperatures when precipitation decreased. This suggests increased water stress may drive upward shifts at lower elevation limits. Our results suggest that species' elevational distribution shifts are not predictable by climate warming alone but depend on the interaction between seasonal temperature and precipitation change.

  2. Climate Warming and Seasonal Precipitation Change Interact to Limit Species Distribution Shifts across Western North America.

    Directory of Open Access Journals (Sweden)

    Melanie A Harsch

    Full Text Available Using an extensive network of occurrence records for 293 plant species collected over the past 40 years across a climatically diverse geographic section of western North America, we find that plant species distributions were just as likely to shift upwards (i.e., towards higher elevations as downward (i.e., towards lower elevations-despite consistent warming across the study area. Although there was no clear directional response to climate warming across the entire study area, there was significant region- to region- variation in responses (i.e. from as many as 73% to as few as 32% of species shifting upward. To understand the factors that might be controlling region-specific distributional shifts of plant species, we explored the relationship between the direction of change in distribution limits and the nature of recent climate change. We found that the direction that distribution limits shifted was explained by an interaction between the rate of change in local summer temperatures and seasonal precipitation. Specifically, species were more likely to shift upward at their upper elevational limit when minimum temperatures increased and snowfall was unchanging or declined at slower rates (<0.5 mm/year. This suggests that both low temperature and water availability limit upward shifts at upper elevation limits. By contrast, species were more likely to shift upwards at their lower elevation limit when maximum temperatures increased, but also shifted upwards under conditions of cooling temperatures when precipitation decreased. This suggests increased water stress may drive upward shifts at lower elevation limits. Our results suggest that species' elevational distribution shifts are not predictable by climate warming alone but depend on the interaction between seasonal temperature and precipitation change.

  3. Climate Warming and Seasonal Precipitation Change Interact to Limit Species Distribution Shifts across Western North America

    Science.gov (United States)

    Harsch, Melanie A.; HilleRisLambers, Janneke

    2016-01-01

    Using an extensive network of occurrence records for 293 plant species collected over the past 40 years across a climatically diverse geographic section of western North America, we find that plant species distributions were just as likely to shift upwards (i.e., towards higher elevations) as downward (i.e., towards lower elevations)–despite consistent warming across the study area. Although there was no clear directional response to climate warming across the entire study area, there was significant region- to region- variation in responses (i.e. from as many as 73% to as few as 32% of species shifting upward). To understand the factors that might be controlling region-specific distributional shifts of plant species, we explored the relationship between the direction of change in distribution limits and the nature of recent climate change. We found that the direction that distribution limits shifted was explained by an interaction between the rate of change in local summer temperatures and seasonal precipitation. Specifically, species were more likely to shift upward at their upper elevational limit when minimum temperatures increased and snowfall was unchanging or declined at slower rates (<0.5 mm/year). This suggests that both low temperature and water availability limit upward shifts at upper elevation limits. By contrast, species were more likely to shift upwards at their lower elevation limit when maximum temperatures increased, but also shifted upwards under conditions of cooling temperatures when precipitation decreased. This suggests increased water stress may drive upward shifts at lower elevation limits. Our results suggest that species’ elevational distribution shifts are not predictable by climate warming alone but depend on the interaction between seasonal temperature and precipitation change. PMID:27447834

  4. Physical processes that drive the seasonal evolution of the Southwestern Tropical Atlantic Warm Pool

    Science.gov (United States)

    Cintra, Marcio M.; Lentini, Carlos A. D.; Servain, Jacques; Araujo, Moacyr; Marone, Eduardo

    2015-12-01

    The thermodynamics of the seasonal evolution of the Southwestern Tropical Atlantic Warm Pool (hereafter SWTAWP), which is delimited by the 28 °C isotherm, is investigated using the Regional Ocean Modeling System (ROMS). Results indicate that the net heat flux is responsible for the appearance and extinction of the SWTAWP. From March to May, the SWTAWP attains its maximum development and sometimes merges with equatorial warm waters towards the African continent, whose development follows the same period. Along the equator, the combination of oceanic terms (i.e., advection and diffusion) is important to promote the separation - when it occurs - of equatorial warm waters from southwestern tropical waters, which develops off the Brazilian coast. An analysis of the relative contribution of the temperature tendency terms of the mixed layer (ML) heat budget over the appearance, development and extinction of the SWTAWP is also done. The most important term for warming and cooling inside of the ML is the net heat flux at the sea surface. The ML is heated by the atmosphere between October and April, whereas the upper ocean cools down between May and September. The highest heat content values occur during the lower-temperature period (August to October), which is linked to the deepening of the ML during this time period. The horizontal advection along the equator is important, particularly at the eastern domain, which is influenced by the cold tongue. In this area, the vertical diffusive term is also significant; however, it presents values near zero outside the equator. These results contribute to a better understanding of the behavior of the heat budget within the tropical Atlantic, as previous studies over this region focused along the equator only.

  5. Seasonal variations in maternal mortality in Maputo, Mozambique: the role of malaria.

    Science.gov (United States)

    Romagosa, Cleofé; Ordi, Jaume; Saute, Francisco; Quintó, Llorenç; Machungo, Fernanda; Ismail, Mamudo R; Carrilho, Carla; Osman, Nafissa; Alonso, Pedro L; Menendez, Clara

    2007-01-01

    To evaluate the impact of malaria on maternal death through the analysis of the seasonal variations of crude and malaria-specific maternal mortality rates. All maternal deaths and live births occurring at Maputo Central Hospital, located in an urban area, between January 2001 and December 2003, were retrospectively recorded. Clinical diagnoses of the causes of death and period of the year were analysed. Two hundred and seventy-eight deaths were recorded. The overall crude maternal mortality rate was 995/100 000 live births. Malaria was the most frequent cause of maternal death, accounting for 23%. Crude and malaria-specific maternal mortality rates showed a similar pattern of seasonal variation, with peaks at the beginning and the end of the malaria transmission season. The malaria-specific maternal mortality rate was significantly higher during the rainy seasons (rate ratio 1.919; 95% CI 1.061, 3.470; P = 0.031). Malaria may contribute to maternal mortality in highly endemic countries in sub-Saharan Africa, at least in urban areas. Efforts to improve malaria control in pregnancy may have an impact on maternal mortality in sub-Saharan Africa.

  6. Ontogenesis and nutritive value of warm-season perennial bunch grasses

    Directory of Open Access Journals (Sweden)

    Robert D. Ziehr

    2014-06-01

    Full Text Available Understanding the dynamics of nutritive values in warm-season perennial bunch grasses with change in ontogenesis is essential to managing their use as forage for livestock or cellulosic bioenergy feedstock. Accumulated growth (not previously harvested of Alamo lowland and accession 9065018 upland switch grass (Panicum virgatum, Lometa Indian grass (Sorghastrum nutans, Earl big bluestem (Andropogon gerardii, San Marcos eastern gama grass (Tripsacum dactyloides and Haskell sideoats grama (Bouteloua curtipendula , all native to the southern Great Plains of North America, as well as Selection 75 Klein grass (Panicum coloratum, originating in southern Africa but selected in North America, was harvested every 28 d for 3 yr, commencing 1 yr after establishment. Growth stage, crude protein (CP and in vitro dry matter disappearance (IVDMD over 48 h were evaluated at each date. Some entries, such as Haskell, San Marcos and Selection 75, initiated reproductive growth earlier in the growing season and had higher nutritive value [up to 119 g CP/kg dry matter (DM and 630 g IVDMD/kg DM] at seed set than those reproducing later in the season. Nutritive value of San Marcos and Selection 75 responded to autumn rainfall with resurging nutritive value (over 100 g CP/kg DM and over 600 g IVDMD/kg DM, whereas others did not. These nuances in nutritive value may be useful in manipulating species composition and season of utilization for grazing bunch grasses, especially when incorporated into opportunistic harvests of bioenergy feedstock. Normal 0 false false false EN-US X-NONE X-NONE

  7. Ontogenesis and nutritive value of warm-season perennial bunch grasses

    Directory of Open Access Journals (Sweden)

    Robert D. Ziehr

    2014-06-01

    Full Text Available Understanding the dynamics of nutritive values in warm-season perennial bunch grasses with change in ontogenesis is essential to managing their use as forage for livestock or cellulosic bioenergy feedstock. Accumulated growth (not previously harvested of Alamo lowland and accession 9065018 upland switch grass (Panicum virgatum, Lometa Indian grass (Sorghastrum nutans, Earl big bluestem (Andropogon gerardii, San Marcos eastern gama grass (Tripsacum dactyloides and Haskell sideoats grama (Bouteloua curtipendula , all native to the southern Great Plains of North America, as well as Selection 75 Klein grass (Panicum coloratum, originating in southern Africa but selected in North America, was harvested every 28 d for 3 yr, commencing 1 yr after establishment. Growth stage, crude protein (CP and in vitro dry matter disappearance (IVDMD over 48 h were evaluated at each date. Some entries, such as Haskell, San Marcos and Selection 75, initiated reproductive growth earlier in the growing season and had higher nutritive value [up to 119 g CP/kg dry matter (DM and 630 g IVDMD/kg DM] at seed set than those reproducing later in the season. Nutritive value of San Marcos and Selection 75 responded to autumn rainfall with resurging nutritive value (over 100 g CP/kg DM and over 600 g IVDMD/kg DM, whereas others did not. These nuances in nutritive value may be useful in manipulating species composition and season of utilization for grazing bunch grasses, especially when incorporated into opportunistic harvests of bioenergy feedstock. Normal 0 false false false EN-US X-NONE X-NONE

  8. Did medieval trade activity and a viral etiology control the spatial extent and seasonal distribution of Black Death mortality?

    Science.gov (United States)

    Bossak, Brian H; Welford, Mark R

    2009-06-01

    Recent research into the world's greatest recorded epidemic, the Medieval Black Death (MBD), has cast doubt on Bubonic Plague as the etiologic agent. Prior research has recently culminated in outstanding advances in our understanding of the spatio-temporal pattern of MBD mortality, and a characterization of the incubation, latent, infectious, and symptomatic periods of the MBD. However, until now, several mysteries remained unexplained, including perhaps the biggest quandary of all: why did the MBD exhibit inverse seasonal peaks in mortality from diseases recorded in modern times, such as seasonal Influenza or the Indian Plague Epidemics of the early 1900 s? Although some have argued that climate changes likely explain the observed differences between modern clinical Bubonic Plague seasonality and MBD mortality accounts, we believe that another factor explains these dissimilarities. Here, we provide a synthetic hypothesis which builds upon previous theories developed in the last ten years or so. Our all-encompassing theory explains the causation, dissemination, and lethality of the MBD. We theorize that the MBD was a human-to-human transmitted virus, originating in East-Central Asia and not Africa (as some recent work has proposed), and that its areal extent during the first great epidemic wave of 1347-1350 was controlled hierarchically by proximity to trade routes. We also propose that the seasonality of medieval trade controlled the warm-weather mortality peaks witnessed during 1347-1350; during the time of greatest market activity, traders, fairgoers, and religious pilgrims served as unintentional vectors of a lethal virus with an incubation period of approximately 32 days, including a largely asymptomatic yet infectious period of roughly three weeks. We include a description of the rigorous research agenda that we have proposed in order to subject our theory to scientific scrutiny and a description of our plans to generate the first publicly available

  9. Disruption of the European climate seasonal clock in a warming world

    Science.gov (United States)

    Cassou, Christophe; Cattiaux, Julien

    2016-06-01

    Temperatures over Europe are largely driven by the strength and inland penetration of the oceanic westerly flow. The wind influence depends on season: blocked westerlies, linked to high-pressure anomalies over Scandinavia, induce cold episodes in winter but warm conditions in summer. Here, we propose to define the onset of the two seasons as the calendar day on which the daily circulation/temperature relationship switches sign. We have assessed this meteorologically based metric using several observational data sets and we provide evidence for an earlier onset of the summer date by ~10 days between the 1960s and 2000s. Results from a climate model show that internal variability alone cannot explain this calendar advance. Rather, the earlier onset can be partly attributed to anthropogenic forcings. The modification of the zonal advection due to earlier disappearance of winter snow over Eastern Europe, which reduces the degree to which climate has continental properties, is mainly responsible for the present-day and near-future advance of the summer date in Western Europe. Our findings are in line with phenological-based trends (earlier spring events) reported for many living species over Europe, for which we provide an alternative interpretation to the traditionally evoked local warming effect. Based on the Representative Concentration Pathway (RCP) 8.5 scenario, which assumes that greenhouse gas emissions continue to rise throughout the twenty-first century, a summer advance of ~20 days compared with pre-industrial climate is expected by 2100, whereas no clear signal arises for winter onset.

  10. Management of warm-season grass mixtures for biomass production in South Dakota USA.

    Science.gov (United States)

    Mulkey, V R; Owens, V N; Lee, D K

    2008-02-01

    Switchgrass (Panicum virgatum L.), big bluestem (Andropogon gerardii Vitman), and indiangrass (Sorghastrum nutans (L.) Nash) are native warm-season grasses commonly used for pasture, hay, and conservation. More recently switchgrass has also been identified as a potential biomass energy crop, but management of mixtures of these species for biomass is not well documented. Therefore, the objectives of our study were to: (1) determine the effects of harvest timing and N rate on yield and biomass characteristics of established warm-season grass stands containing a mixture of switchgrass, big bluestem, and indiangrass, and (2) evaluate the impact of harvest management on species composition. Five N rates (0, 56, 112, and 224 kg ha(-1) applied annually in spring and 224 kg ha(-1) evenly split between spring and fall) and two harvest timings (anthesis and killing frost) were applied to plots at two South Dakota USA locations from 2001 to 2003. Harvesting once a year shortly after a killing frost produced the greatest yields with high concentrations of neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL) along with lower concentrations of total nitrogen (TN) and ash. This harvest timing also allowed for the greatest percentage of desirable species while maintaining low grass weed percentages. While N rates of 56 and 112 kg ha(-1) tended to increase total biomass without promoting severe invasion of grass and broadleaf weed species, N application did not always result in significant increases in biomass production. Based on these results, mixtures of switchgrass and big bluestem were well suited for sustainable biomass energy production. Furthermore, N requirements of these mixtures were relatively low thus reducing production input costs.

  11. Experimental warming and precipitation interactively modulate the mortality rate and timing of spring emergence of a gallmaking Tephritid fly

    Science.gov (United States)

    Xi, Xinqiang; Li, Dongbo; Peng, Youhong; Eisenhauer, Nico; Sun, Shucun

    2016-08-01

    Global climate change is mostly characterized by temperature increase and fluctuating precipitation events, which may affect the spring phenology and mortality rate of insects. However, the interaction effect of temperature and precipitation on species performance has rarely been examined. Here we studied the response of the gall-making Tephritid fly Urophora stylata (Diptera: Tephritidae) to artificial warming, changes in precipitation, and the presence of galls. Our results revealed a significant interaction effect of warming, precipitation, and galls on the life-history traits of the focal species. Specifically, when the galls were intact, warming had no effect on the phenology and increased the mortality of the fly under decreased precipitation, but it significantly advanced the timing of adult emergence and had no effect on the mortality under increased precipitation. When galls were removed, warming significantly advanced the timing of emergence and increased fly mortality, but precipitation showed no effect on the phenology and mortality. In addition, gall removal significantly increased adult fresh mass for both females and males. Our results indicate that the effect of elevated temperature on the performance of species may depend on other environmental conditions, such as variations in precipitation, and species traits like the formation of galls.

  12. Experimental warming and precipitation interactively modulate the mortality rate and timing of spring emergence of a gallmaking Tephritid fly.

    Science.gov (United States)

    Xi, Xinqiang; Li, Dongbo; Peng, Youhong; Eisenhauer, Nico; Sun, Shucun

    2016-08-31

    Global climate change is mostly characterized by temperature increase and fluctuating precipitation events, which may affect the spring phenology and mortality rate of insects. However, the interaction effect of temperature and precipitation on species performance has rarely been examined. Here we studied the response of the gall-making Tephritid fly Urophora stylata (Diptera: Tephritidae) to artificial warming, changes in precipitation, and the presence of galls. Our results revealed a significant interaction effect of warming, precipitation, and galls on the life-history traits of the focal species. Specifically, when the galls were intact, warming had no effect on the phenology and increased the mortality of the fly under decreased precipitation, but it significantly advanced the timing of adult emergence and had no effect on the mortality under increased precipitation. When galls were removed, warming significantly advanced the timing of emergence and increased fly mortality, but precipitation showed no effect on the phenology and mortality. In addition, gall removal significantly increased adult fresh mass for both females and males. Our results indicate that the effect of elevated temperature on the performance of species may depend on other environmental conditions, such as variations in precipitation, and species traits like the formation of galls.

  13. Seasonal variation of natural mortality factors of the guava psyllid Triozoida limbata.

    Science.gov (United States)

    Semeão, A A; Martins, J C; Picanço, M C; Chediak, M; da Silva, E M; Silva, G A

    2012-12-01

    It is important to understand how components of the agroecosystem interfere with the attack of a pest species and their seasonality in order to use these components in IPM programs. This study focused on the evaluation of the seasonality of natural control factors associated with the guava psyllid Triozoida limbata (Enderlein) in Brazil. Life-table data were collected from an experimental guava orchard during four periods that roughly represented four seasons. Natural mortality was monitored daily through the immature stages, and the relative importance of each natural mortality factor and its seasonality was determined. Significant statistical differences were observed in the mortality during the four periods (P analysis (PCA) showed some trends in the relationship of natural control agents and weather conditions. For example, the occurrence of predatory wasps was positively correlated with temperature and occurrence of winds; the occurrence of syrphids and Psyllaephagus sp. were negatively correlated with temperature and winds; and the occurrence of other generalist predators were negatively correlated with the occurrence of rainfall and photoperiod. The results showed the importance of natural mortality factors for the management of T. limbata and their changes through the different seasons which should be considered when implementing IPM programs in guava orchards.

  14. Seasonal patterns of SST diurnal variation over the Tropical Warm Pool region

    Science.gov (United States)

    Zhang, Haifeng; Beggs, Helen; Wang, Xiao Hua; Kiss, Andrew E.; Griffin, Christopher

    2016-11-01

    Five year (2010-2014) Advanced Very High Resolution Radiometer (AVHRR) sea surface temperature (SST) data produced by the Australian Bureau of Meteorology have been validated against drifting buoy data and then used to study the seasonal patterns of the SST diurnal variation (DV) events over the Tropical Warm Pool region (TWP, 25°S-15°N, 90°E-170°E). The in situ validation results illustrate the overall good quality of the AVHRR SST data set, although an average 0.19 K underestimation of the daytime measurements has been observed. The nighttime observations are in good agreement with in situ buoys with an average bias of 0.03 and a 0.30 K standard deviation of the biases. This SST data set is then used to characterize the SST DV seasonal patterns, together with wind speeds, daily maximum solar shortwave insolation (SSImax), and latent heat flux (LHF). A double-peak seasonal pattern of SST DV is observed over the study region: the strongest DVs are found in March and October and the weakest in June. Sensitivity tests of DV to wind, SSImax, and LHF are conducted. The results indicate (1) different morning and early afternoon winds (7 A.M. to 2 P.M. local time, LT) affect DV by as much as 0.73 K when the half-daily (defined as 2 A.M. to 2 P.M. LT in this study) average winds are fixed between 2 and 3 m s-1; (2) SSImax levels regulate DV less significantly (<0.68 K) under fixed winds; and (3) LHF effects on DV are relatively weak (<0.35 K).

  15. Positive effects of night warming on physiology of coniferous trees in late growing season: Leaf and root

    Science.gov (United States)

    Tang, Bo; Yin, Chunying; Wang, Yujie; Sun, Yuyu; Liu, Qing

    2016-05-01

    Previous studies about the effects of experimental warming on tree species have focused primarily on response of morphology and physiology in leaf and biomass allocation in the growing season, and a few studies considered the importance of roots. Based on the available evidence, it is unclear whether photosynthesis rate is enhanced by night warming in late autumn an issue that deserves further investigation. Thus, we exposed two coniferous species, Picea asperata and Abies faxoniana, to night warming continued throughout the year to investigate morphological and physiological responses of roots and leaves in the autumn. The results showed that night warming caused significant increases in net influxes of NH4+ and NO3- in P. asperata seedlings corresponding well with net H+ efflux and net influx of O2. Meanwhile, night warming had a positive effect on foliar gas exchange such as net photosynthesis rate, apparent quantum efficiency, dark respiration rate and maximum quantum efficiency of PS II, and nitrate reductase activity of roots. Additionally, root morphology such as total roots length, surface area, specific root area and specific root length was also stimulated by night warming. In contrast, night warming decreased concentrations of non-structural carbohydrate in leaves and roots of both species in autumn. The present study demonstrates that night warming would enhance late autumn leaf photosynthetic rate, and increase N uptake capacity of roots.

  16. Effect of feeding warm-season annuals with orchardgrass on ruminal fermentation and methane output in continuous culture

    Science.gov (United States)

    A 4-unit, dual-flow continuous culture fermentor system was used to assess nutrient digestibility, volatile fatty acids (VFA) production, bacterial protein synthesis and CH4 output of warm-season summer annual grasses. Treatments were randomly assigned to fermentors in a 4 × 4 Latin square design us...

  17. Self-seeding warm-season legumes for low-input forage production in the southern Great Plains of the USA

    Science.gov (United States)

    In the southern Great Plains (SGP) of the USA warm-season legumes can improve the quality of available forage in pasture systems based on perennial warm-season grasses. Legumes that persist through self-seeding may be especially useful in low-input systems where resources for annual replanting are l...

  18. The effects of season and meteorology on human mortality in tropical climates: a systematic review.

    Science.gov (United States)

    Burkart, Katrin; Khan, Md Mobarak Hossain; Schneider, Alexandra; Breitner, Susanne; Langner, Marcel; Krämer, Alexander; Endlicher, Wilfried

    2014-07-01

    Research in the field of atmospheric science and epidemiology has long recognized the health effects of seasonal and meteorological conditions. However, little scientific knowledge exists to date about the impacts of atmospheric parameters on human mortality in tropical regions. Working within the scope of this systematic review, this investigation conducted a literature search using different databases; original research articles were chosen according to pre-defined inclusion and exclusion criteria. Both seasonal and meteorological effects were considered. The findings suggest that high amounts of rainfall and increasing temperatures cause a seasonal excess in infectious disease mortality and are therefore relevant in regions and populations in which such diseases are prevalent. On the contrary, moderately low and very high temperatures exercise an adverse effect on cardio-respiratory mortality and shape the mortality pattern in areas and sub-groups in which these diseases are dominant. Atmospheric effects were subject to population-specific factors such as age and socio-economic status and differed between urban and rural areas. The consequences of climate change as well as environmental, epidemiological and social change (e.g., emerging non-communicable diseases, ageing of the population, urbanization) suggest a growing relevance of heat-related excess mortality in tropical regions.

  19. Warm and dry weather accelerates and elongates Cladosporium spore seasons in Poland.

    Science.gov (United States)

    Kasprzyk, Idalia; Kaszewski, Boguslaw Michal; Weryszko-Chmielewska, Elzbieta; Nowak, Malgorzata; Sulborska, Aneta; Kaczmarek, Joanna; Szymanska, Agata; Haratym, Weronika; Jedryczka, Malgorzata

    Temperature is the environmental factor that systematically changes for decades and, as in plants and animals, can significantly affect the growth and development of fungi, including the abundance of their sporulation. During the time of study (2010-2012), a rapid increase in air temperature was observed in Poland, which coincided with the substantial decrease in rainfall. The increase in annual mean temperatures at three monitoring sites of this study was 0.9 °C in Lublin and Rzeszow (east Poland) and 2.0 °C in Poznan (west Poland). Such warming of air masses was comparable to the average global air temperature rise in the period of 1880-2012 accounting for 0.85 °C, as reported by the Intergovernmental Panel on Climate Change. Moreover, there was a substantial decrease in rainfall, ranging from 32.7 % (Poznan) to 43.0 % (Rzeszow). We have demonstrated that under such conditions the mean and median values of total Cladosporium spore counts significantly increased and the spore seasons were greatly accelerated. Moreover, earlier start and later end of the season caused its extension, lasting from over 20 days in Rzeszow to around 60 days in Lublin and Poznan, when the cumulative amount of 5-95 % of spores was considered. The time of reaching the cumulative amount of 50 % of spores was up to 25 days earlier (difference in Poznan between 2010 and 2012). There was also a striking acceleration of the date of the maximal Cladosporium spore concentration per cubic metre of air (26 days for Lublin, 43 for Poznan and 56 for Rzeszow).

  20. Integrated rice-duck farming mitigates the global warming potential in rice season.

    Science.gov (United States)

    Xu, Guochun; Liu, Xin; Wang, Qiangsheng; Yu, Xichen; Hang, Yuhao

    2017-01-01

    Integrated rice-duck farming (IRDF), as a mode of ecological agriculture, is an important way to realize sustainable development of agriculture. A 2-year split-plot field experiment was performed to evaluate the effects of IRDF on methane (CH4) and nitrous oxide (N2O) emissions and its ecological mechanism in rice season. This experiment was conducted with two rice farming systems (FS) of IRDF and conventional farming (CF) under four paddy-upland rotation systems (PUR): rice-fallow (RF), annual straw incorporating in rice-wheat rotation system (RWS), annual straw-based biogas residues incorporating in rice-wheat rotation system (RWB), and rice-green manure (RGM). During the rice growing seasons, IRDF decreased the CH4 emission by 8.80-16.68%, while increased the N2O emission by 4.23-15.20%, when compared to CF. Given that CH4 emission contributed to 85.83-96.22% of global warming potential (GWP), the strong reduction in CH4 emission led to a significantly lower GWP of IRDF as compared to CF. The reason for this trend was because IRDF has significant effect on dissolved oxygen (DO) and soil redox potential (Eh), which were two pivotal factors for CH4 and N2O emissions in this study. The IRDF not only mitigates the GWP, but also increases the rice yield by 0.76-2.43% compared to CF. Moreover, compared to RWS system, RF, RWB and RGM systems significantly reduced CH4 emission by 50.17%, 44.89% and 39.51%, respectively, while increased N2O emission by 10.58%, 14.60% and 23.90%, respectively. And RWS system had the highest GWP. These findings suggest that mitigating GWP and improving rice yield could be simultaneously achieved by the IRDF, and employing suitable PUR would benefit for relieving greenhouse effect. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Darcy’s law predicts widespread forest mortality under climate warming

    Science.gov (United States)

    McDowell, Nate G.; Allen, Craig D.

    2015-01-01

    Drought and heat-induced tree mortality is accelerating in many forest biomes as a consequence of a warming climate, resulting in a threat to global forests unlike any in recorded history1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12. Forests store the majority of terrestrial carbon, thus their loss may have significant and sustained impacts on the global carbon cycle11,12. We use a hydraulic corollary to Darcy’s law, a core principle of vascular plant physiology13, to predict characteristics of plants that will survive and die during drought under warmer future climates. Plants that are tall with isohydric stomatal regulation, low hydraulic conductance, and high leaf area are most likely to die from future drought stress. Thus, tall trees of old-growth forests are at the greatest risk of loss, which has ominous implications for terrestrial carbon storage. This application of Darcy’s law indicates today’s forests generally should be replaced by shorter and more xeric plants, owing to future warmer droughts and associated wildfires and pest attacks. The Darcy’s corollary also provides a simple, robust framework for informing forest management interventions needed to promote the survival of current forests. Given the robustness of Darcy’s law for predictions of vascular plant function, we conclude with high certainty that today’s forests are going to be subject to continued increases in mortality rates that will result in substantial reorganization of their structure and carbon storage.

  2. Role of Acclimatization in Weather-Related Human Mortality During the Transition Seasons of Autumn and Spring in a Thermally Extreme Mid-Latitude Continental Climate.

    Science.gov (United States)

    de Freitas, Christopher R; Grigorieva, Elena A

    2015-11-26

    Human mortality is closely related to natural climate-determined levels of thermal environmental stress and the resulting thermophysiological strain. Most climate-mortality research has focused on seasonal extremes during winter and summer when mortality is the highest, while relatively little attention has been paid to mortality during the transitional seasons of autumn and spring. The body acclimatizes to heat in the summer and cold in winter and readjusts through acclimatization during the transitions between the two during which time the body experiences the thermophysiological strain of readjustment. To better understand the influences of weather on mortality through the acclimatization process, the aim here is to examine the periods that link very cold and very warms seasons. The study uses the Acclimatization Thermal Strain Index (ATSI), which is a comparative measure of short-term thermophysiological impact on the body. ATSI centers on heat exchange with the body’s core via the respiratory system, which cannot be protected. The analysis is based on data for a major city in the climatic region of the Russian Far East characterized by very hot summers and extremely cold winters. The results show that although mortality peaks in winter (January) and is at its lowest in summer (August), there is not a smooth rise through autumn nor a smooth decline through spring. A secondary peak occurs in autumn (October) with a smaller jump in May. This suggests the acclimatization from warm-to-cold produces more thermophysiological strain than the transition from cold-to-warm. The study shows that ATSI is a useful metric for quantifying the extent to which biophysical adaptation plays a role in increased strain on the body during re-acclimatization and for this reason is a more appropriate climatic indictor than air temperature alone. The work gives useful bioclimatic information on risks involved in transitional seasons in regions characterized by climatic extremes. This

  3. Warming affects hatching time and early season survival of eastern tent caterpillars.

    Science.gov (United States)

    Abarca, Mariana; Lill, John T

    2015-11-01

    Climate change is disrupting species interactions by altering the timing of phenological events such as budburst for plants and hatching for insects. We combined field observations with laboratory manipulations to investigate the consequences of climate warming on the phenology and performance of the eastern tent caterpillar (Malacosoma americanum). We evaluated the effects of warmer winter and spring regimes on caterpillar hatching patterns and starvation endurance, traits likely to be under selection in populations experiencing phenological asynchrony, using individuals from two different populations (Washington, DC, and Roswell, GA). We also quantified the proximate and extended fitness effects of early food deprivation and recorded spring phenology of local caterpillars and their host plants. In addition, we conducted laboratory assays to determine if caterpillars are using plant chemical cues to fine-tune their hatching times. Warmer winter temperatures induced earlier hatching and caterpillars from GA survived starvation for periods that were 30% longer than caterpillars from DC. Warmer spring regimes reduced the starvation endurance of caterpillars overwintering in the wild but not in the laboratory. Early starvation dramatically reduced hatchling survival; however, surviving caterpillars did not show detrimental effects on pupal mass or development time. In the field, hatching preceded budburst in both 2013 and 2014 and the period of optimal foliage quality was 2 weeks shorter in 2013. Hatching time was unaffected by exposure to plant volatiles. Overall, we found that warmer temperatures can trigger late-season asynchrony by accelerating plant phenology and caterpillars from different populations exhibit differential abilities to cope with environmental unreliability.

  4. Evaluation of Warm Season Turfgrass under Different Irrigation Regimes in Arid Region

    Directory of Open Access Journals (Sweden)

    Abdullah Mohd Hassan ALSHEHHI

    2010-09-01

    Full Text Available Turfgrasses play a very important role in enhancing quality of life in modern urban living. Water quantity is the most important challenge worldwide in establishing and maintaining quality turf. The present study was aimed to test the performance of three warm season turfgrasses under four water levels for plantation in arid zones. Pits (48 measuring 1m length x 1m width x 0.6 m depth were planted with four replications of Common Bermuda grass (Cynodon dactylon, Tifway Bermuda grass (Cynodon dactylon x transvaalensis and Seashore Paspalum grass (Paspalum vaginatum in complete randomized design (CRD. Irrigation was done daily with 15 l/plot during the first 4 weeks (establishment period and four irrigation levels (5, 10, and 15, 20 l/lot were maintained in the following 8 weeks (treatment period. Physical parameters (canopy temperatures, ambient temperature, leaf area, shoot production and relative water content were measured once in two week as well as the visual quality (shoot color, shoot density and shoot uniformity was assessed, however, chlorophyll analysis was done in the end of the study. It was found that temperature has significant effect on performance of turfgrasses. Canopy temperature was higher than ambient temperature in the three turfgrasses but it has different level in each variety. Five liter of water per day per square meter gave acceptable turf quality when ambient temperature ranged from 20 to 33C. Seashore paspalum performed best followed by Tifway Bermuda grass and common Bermuda grass respectively.

  5. Corresponding Relation between Warm Season Precipitation Extremes and Surface Air Temperature in South China

    Institute of Scientific and Technical Information of China (English)

    SUN; Wei; LI; Jian; YU; Ru-Cong

    2013-01-01

    Hourly data of 42 rain gauges over South China during 1966–2005 were used to analyze the corresponding relation between precipitation extremes and surface air temperature in the warm season(May to October).The results show that below 25℃,both daily and hourly precipitation extremes in South China increase with rising temperature.More extreme events transit to the two-time Clausius-Clapeyron(CC)relationship at lower temperatures.Daily as well as hourly precipitation extremes have a decreasing tendency nearly above 25℃,among which the decrease of hourly extremes is much more significant.In order to investigate the efects of rainfall durations,hourly precipitation extremes are presented by short duration and long duration precipitation,respectively.Results show that the dramatic decrease of hourly rainfall intensities above 25℃ is mainly caused by short duration precipitation,and long duration precipitation extremes rarely occur in South China when surface air temperature surpasses 28℃.

  6. Characteristics of climate change in the “significant impact zone” affected by aerosols over eastern China in warm seasons

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Through analysis of the distribution pattern and changing characteristics of atmospheric aerosols over the East Asia region during warm seasons in recent 20 a and beyond as well as their possible interac- tive relationship with a variety of meteorological elements, it is found that the high-value zone of aerosol optical depth derived from the Total Ozone Mapping Spectrometer (TOMS), its significant negative correlation zones in terms of sunshine duration (SD) and surface air temperature (SAT) and its significant positive correlation zones with low-level cloud amount (LCC) are co-located in the South China region during warm periods. Based on this finding, the region is referred to as a "significant impact zone" (SI zone) affected by aerosols. Then, a comparative analysis is made on variation differ- ences of observed SAT, SD and LCC, etc. in different regions. It is also found that the LCC is increased and the SD is decreased within the "SI zone" over eastern China during the warm season. These characteristics are more evident than those beyond the zone, while the warming trend within the zone is evidently weaker than that outside it. Studies show that since recent 20 a, under the influence of aerosols, the LCC tend to increase substantially with a clear decrease of SD and an unnoticeable warming trend within the "SI zone". Comparing with the climate change beyond the zone, the difference is significant. Therefore, the effects of atmospheric aerosols on climate is possibly one of the contri- butions to the difference of climate change existed between the southern and northern parts of the Eastern China during a warm season.

  7. Heat-Related Mortality in a Warming Climate: Projections for 12 U.S. Cities

    Directory of Open Access Journals (Sweden)

    Elisaveta P. Petkova

    2014-10-01

    Full Text Available Heat is among the deadliest weather-related phenomena in the United States, and the number of heat-related deaths may increase under a changing climate, particularly in urban areas. Regional adaptation planning is unfortunately often limited by the lack of quantitative information on potential future health responses. This study presents an assessment of the future impacts of climate change on heat-related mortality in 12 cities using 16 global climate models, driven by two scenarios of greenhouse gas emissions. Although the magnitude of the projected heat effects was found to differ across time, cities, climate models and greenhouse pollution emissions scenarios, climate change was projected to result in increases in heat-related fatalities over time throughout the 21st century in all of the 12 cities included in this study. The increase was more substantial under the high emission pathway, highlighting the potential benefits to public health of reducing greenhouse gas emissions. Nearly 200,000 heat-related deaths are projected to occur in the 12 cities by the end of the century due to climate warming, over 22,000 of which could be avoided if we follow a low GHG emission pathway. The presented estimates can be of value to local decision makers and stakeholders interested in developing strategies to reduce these impacts and building climate change resilience.

  8. Heat-Related Mortality in a Warming Climate: Projections for 12 U.S. Cities

    Science.gov (United States)

    Petkova, Elisaveta P.; Bader, Daniel A.; Anderson, G. Brooke; Horton, Radley M.; Knowlton, Kim; Kinney, Patrick L.

    2014-01-01

    Heat is among the deadliest weather-related phenomena in the United States, and the number of heat-related deaths may increase under a changing climate, particularly in urban areas. Regional adaptation planning is unfortunately often limited by the lack of quantitative information on potential future health responses. This study presents an assessment of the future impacts of climate change on heat-related mortality in 12 cities using 16 global climate models, driven by two scenarios of greenhouse gas emissions. Although the magnitude of the projected heat effects was found to differ across time, cities, climate models and greenhouse pollution emissions scenarios, climate change was projected to result in increases in heat-related fatalities over time throughout the 21st century in all of the 12 cities included in this study. The increase was more substantial under the high emission pathway, highlighting the potential benefits to public health of reducing greenhouse gas emissions. Nearly 200,000 heat-related deaths are projected to occur in the 12 cities by the end of the century due to climate warming, over 22,000 of which could be avoided if we follow a low GHG emission pathway. The presented estimates can be of value to local decision makers and stakeholders interested in developing strategies to reduce these impacts and building climate change resilience. PMID:25365060

  9. European seasonal mortality and influenza incidence due to winter temperature variability

    Science.gov (United States)

    Ballester, Joan; Rodó, Xavier; Robine, Jean-Marie; Herrmann, François Richard

    2016-10-01

    Recent studies have vividly emphasized the lack of consensus on the degree of vulnerability (see ref. ) of European societies to current and future winter temperatures. Here we consider several climate factors, influenza incidence and daily numbers of deaths to characterize the relationship between winter temperature and mortality in a very large ensemble of European regions representing more than 400 million people. Analyses highlight the strong association between the year-to-year fluctuations in winter mean temperature and mortality, with higher seasonal cases during harsh winters, in all of the countries except the United Kingdom, the Netherlands and Belgium. This spatial distribution contrasts with the well-documented latitudinal orientation of the dependency between daily temperature and mortality within the season. A theoretical framework is proposed to reconcile the apparent contradictions between recent studies, offering an interpretation to regional differences in the vulnerability to daily, seasonal and long-term winter temperature variability. Despite the lack of a strong year-to-year association between winter mean values in some countries, it can be concluded that warmer winters will contribute to the decrease in winter mortality everywhere in Europe.

  10. Assessing the relationship between global warming and mortality: Lag effects of temperature fluctuations by age and mortality categories

    Energy Technology Data Exchange (ETDEWEB)

    Yu Weiwei, E-mail: weiwei.yu@qut.edu.au [School of Public Health and Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, QLD 4050, Brisbane (Australia); Mengersen, Kerrie [Discipline of Mathematical Sciences, Faculty of Science and Technology, Queensland University of Technology, Brisbane (Australia); Hu Wenbiao [School of Population Health and Institute of Health and Biomedical Innovation, University of Queensland, Brisbane (Australia); Guo Yuming [School of Public Health and Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, QLD 4050, Brisbane (Australia); Pan Xiaochuan [School of Public Health, Peking University, Beijing 100191 (China); Tong Shilu, E-mail: s.tong@qut.edu.au [School of Public Health and Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, QLD 4050, Brisbane (Australia)

    2011-07-15

    Although interests in assessing the relationship between temperature and mortality have arisen due to climate change, relatively few data are available on lag structure of temperature-mortality relationship, particularly in the Southern Hemisphere. This study identified the lag effects of mean temperature on mortality among age groups and death categories using polynomial distributed lag models in Brisbane, Australia, a subtropical city, 1996-2004. For a 1 deg. C increase above the threshold, the highest percent increase in mortality on the current day occurred among people over 85 years (7.2% (95% CI: 4.3%, 10.2%)). The effect estimates among cardiovascular deaths were higher than those among all-cause mortality. For a 1 deg. C decrease below the threshold, the percent increases in mortality at 21 lag days were 3.9% (95% CI: 1.9%, 6.0%) and 3.4% (95% CI: 0.9%, 6.0%) for people aged over 85 years and with cardiovascular diseases, respectively. These findings may have implications for developing intervention strategies to reduce and prevent temperature-related mortality. - Highlights: > A longer lag effects in cold days and shorter lag effects in hot days. > The very old people were most vulnerable to temperature stress. > The cardiovascular mortality was also sensitive to the temperature variation. - In Brisbane, the lag effects lasted longer for cold temperatures, and shorter for hot temperatures. Elderly people and cardiovascular mortality were vulnerable to temperature stress.

  11. The potential effect of global warming on the geographic and seasonal distribution of Phlebotomus papatasi in southwest Asia.

    OpenAIRE

    Cross, E R; Hyams, K C

    1996-01-01

    The distribution of Phlebotomus papatasi in Southwest Asia is thought to be highly dependent on temperature and relative humidity. A discriminant analysis model based on weather data and reported vector surveys was developed to predict the seasonal and geographic distribution of P. papatasi in this region. To simulate global warming, temperature values for 115 weather stations were increased by 1 degree C, 3 degrees C, and 5 degrees C, and the outcome variable coded as unknown in the model. P...

  12. Is Ekman pumping responsible for the seasonal variation of warm circumpolar deep water in the Amundsen Sea?

    Science.gov (United States)

    Kim, T. W.; Ha, H. K.; Wåhlin, A. K.; Lee, S. H.; Kim, C. S.; Lee, J. H.; Cho, Y. K.

    2017-01-01

    Ekman pumping induced by horizontally varying wind and sea ice drift is examined as an explanation for observed seasonal variation of the warm layer thickness of circumpolar deep water on the Amundsen Sea continental shelf. Spatial and temporal variation of the warm layer thickness in one of the deep troughs on the shelf (Dotson Trough) was measured during two oceanographic surveys and a two-year mooring deployment. A hydrographic transect from the deep ocean, across the shelf break, and into the trough shows a local elevation of the warm layer at the shelf break. On the shelf, the water flows south-east along the trough, gradually becoming colder and fresher due to mixing with cold water masses. A mooring placed in the trough shows a thicker and warmer layer in February and March (late summer/early autumn) and thinner and colder layer in September, October and November (late winter/early spring). The amplitude of this seasonal variation is up to 60 m. In order to investigate the effects of Ekman pumping, remotely sensed wind (Antarctic Mesoscale Prediction System wind data) and sea ice velocity and concentration (EASE Polar Pathfinder) were used. From the estimated surface stress field, the Ekman transport and Ekman pumping were calculated. At the shelf break, where the warm layer is elevated, the Ekman pumping shows a seasonal variation correlating with the mooring data. Previous studies have not been able to show a correlation between observed wind and bottom temperature, but it is shown here that when sea ice drift is taken into account the Ekman pumping at the outer shelf correlates with bottom temperature in Dotson Trough. The reason why the Ekman pumping varies seasonally at the shelf break appears to be the migration of the ice edge in the expanding polynya in combination with the wind field which on average is westward south of the shelf break.

  13. Assessing Climate Change Impacts for DoD installations in the Southwest United States During the Warm Season

    Science.gov (United States)

    2017-03-10

    FINAL REPORT Assessing Climate Change Impacts for DoD Installations in the Southwest United States During the Warm Season SERDP Project RC...DATES COVERED (From - To) March 2012 to March 2017 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Assessing climate change impacts for DoD installations in...select NARCCAP and UA-ATMO downscaled CMIP models. Figure 9: July-August precipitation during the period of historical climate versus climate change

  14. The Characteristics of Mesoscale Convective Systems (MCSs) over East Asia in Warm Seasons

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Mesoscale convective system (MCS) cloud clusters,defined using an objective recognition analysis based on hourly geostationary infrared satellite data over East Asia during the warm seasons of 1996-2008 (except 2004),were investigated in this study.The geographical pattern of MCS distribution over East Asia shows several high-frequency centers at low latitudes,including the Indo-China peninsula,the Bay of Bengal,the Andaman Sea,the Brahmaputra river delta,the south China coastal region,and the Philippine Islands.There are several middle-frequency centers in the middle latitudes,e.g.,the central-east of the Tibet Plateau,the Plateau of west Sichuan,Mount Wuyi,and the Sayan Mountains in Russia;whereas in Lake Baikal,the Tarim Basin,the Taklimakan Desert,the Sea of Japan,and the Sea of Okhotsk,rare MCS distributions are observed.MCSs are most intensely active in summer,with the highest monthly frequency in July,which is partly associated with the breaking out and prevailing of the summer monsoon in East Asia.An obvious diurnal cycle feature is also found in MCS activities,which shows that MCSs are triggered in the afternoon,mature in the evening,and dissipate at night.MCS patterns over East Asia can be characterized as small,short-lived,or elongated,which move slowly and usually lead to heavy rains or floods.

  15. Optimization of precipitation and streamflow forecasts in the southwest Contiguous US for warm season convection

    Science.gov (United States)

    Lahmers, T.; Castro, C. L.; Gupta, H. V.; Gochis, D. J.; ElSaadani, M.

    2015-12-01

    Warm season convection associated with the North American Monsoon (NAM) provides an important source of precipitation for much of the Southwest Contiguous US (CONUS) and Northwest Mexico. Convection associated with the NAM can also result in flash flooding, a hazard to metropolitan areas such as Tucson and Phoenix, as well as rural areas where washouts of main roads can sever critical transportation infrastructure. In order to mitigate the effects of this problem, the National Oceanic and Atmospheric Administration (NOAA) National Water Center (NWC) is developing a national distributed hydrologic model using the WRF-Hydro framework with forcing from the High Resolution Rapid Refresh (HRRR) mesoscale atmospheric model. We aim to improve this National hydrologic and atmospheric modeling framework through the calibration of the WRF-Hydro model for the southwest CONUS and the optimization of planetary boundary layer and cloud microphysics schemes for the Weather Research and Forecasting (WRF) model in the same region. The WRF-Hydro model, with a similar structure as the national configuration used by the NWC, has been set up for the Gila River basin in southern Arizona. We demonstrate the utility of the model for forecasting high impact precipitation events in catchments with limited human modification. The WRF-Hydro model is spun up using past precipitation from the NCEP Stage-IV records and TRMM estimates. Atmospheric forcing for WRF-Hydro comes from the NASA Phase 2 North American Land Data Assimilation (NLDAS-2) dataset. WRF-Hydro is forced for selected high-impact events using a 3-km grid resolution Advanced Research WRF (WRF-ARW) atmospheric simulation. WRF-ARW is forced with the operational National Center for Environmental Prediction (NCEP) Global Forecasting System (GFS) operational model. This methodology demonstrates the modeling framework that will be used for future parameter calibration of WRF-Hydro and optimization of WRF-ARW.

  16. Impact of land surface processes on the South American warm season climate

    Energy Technology Data Exchange (ETDEWEB)

    Ma, H.-Y.; Mechoso, C.R.; Xiao, H.; Wu, C.-M. [University of California Los Angeles, Department of Atmospheric and Oceanic Sciences, Los Angeles, CA (United States); Xue, Y. [University of California Los Angeles, Department of Atmospheric and Oceanic Sciences, Los Angeles, CA (United States); University of California Los Angeles, Department of Geography, Los Angeles, CA (United States); Li, J.-L. [California Institute of Technology, Jet Propulsion Laboratory, Pasadena, CA (United States); Sales, F.De [University of California Los Angeles, Department of Geography, Los Angeles, CA (United States)

    2011-07-15

    The present study demonstrates that (1) the simulation of the South American warm season (December-February) climate by an atmospheric general circulation model (AGCM) is sensitive to the representation of land surface processes, (2) the sensitivity is not confined to the ''hot spot'' in Amazonia, and (3) upgrading the representation of those processes can produce a significant improvement in AGCM performance. The reasons for sensitivity and higher success are investigated based on comparisons between observational datasets and simulations by the AGCM coupled to either a simple land scheme that specifies soil moisture availability or to the Simplified Simple Biosphere Model (SSiB) that allows for consideration of soil and vegetation biophysical process. The context for the study is the UCLA AGCM. The most notable simulation improvements are along the lee of the Andes in the lower troposphere, where poleward flow transports abundant moisture from the Amazon basin to high latitudes, and in the monsoon region where the intensity and pattern of precipitation and upper level ice water content are more realistic. It is argued that a better depiction of the Chaco Low, which is controlled by local effects of land surface processes, decisively contributes to the superior model performance with low-level flows in central South America. The better representation of the atmospheric column static stability and large-scale moisture convergence in tropical South America contribute to more realistic precipitation over the monsoon region. The overall simulation improvement is, therefore, due to a combination of different regional processes. This finding is supported by idealized AGCM experiments. (orig.)

  17. Highway Roadway Stability Influenced by Warm Permafrost and Seasonal Frost Action:A Case Study from Glennallen,Alaska,USA

    Institute of Scientific and Technical Information of China (English)

    Max; C.Brewer

    2008-01-01

    Ground temperatures from four of the seven extensively studied highway cross-sections near Gulkana/Glennallen,Alaska during 1954~1962,were chosen to better understand the impacts of highway construction on warm permafrost.Both the thawing of permafrost and seasonal frost action impacted on road surface stability for about 6 years until the maximum summer thaw reached about 3 m in depth.Seasonal frost action caused most of the ensuing stability problems.Unusually warm summers and the lengths of time required to re-freeze the active layer were far more important than the average annual air temperatures in determining the temperatures of the underlying shallow permafrost,or the development of taliks.The hypothesized climate warming would slightly and gradually deepen the active layer and the developed under-lying talik,but its effect would be obscured by unusually warm summers,by warmer than usual winters,and by the vari-able lengths of time of the zero curtains.At least one period of climate mini-cooling in the deeper permafrost during the early 20th century was noted.

  18. The effects of radiative and microphysical processes on simulated warm and transition season arctic stratus

    Science.gov (United States)

    Harrington, Jerry Y.

    A cloud-resolving model (CRM) version of RAMS, coupled to explicit bin resolving microphysics and a new two-stream radiative transfer code is used to study various aspects of Arctic stratus clouds (ASC). The two-stream radiative transfer model is coupled in a consistent fashion to the bulk microphysical parameterization of Walko et al., (1995), an explicit liquid bin microphysical model (e.g., Feingold et al., 1996a) and a mixed-phase microphysical model (Reisin et al., 1996). These models are used to study both warm (summer) season and transition (fall and spring) season ASC. Equations are developed for the inclusion of the radiative term in the drop growth equation and the effect is studied in a trajectory parcel model (TPM) and the CRM. Arctic stratus simulated with the new CRM framework compared well with the observations of Curry (1986). Along with CCN concentrations, it is shown that drop distribution shape and optical property methods strongly impact cloud evolution through their effect on the radiative properties. Broader cloud top distributions lead to clouds with more shallow depths and circulation strengths as more shortwave radiation is absorbed while the opposite occurs for narrow distribution functions. Radiative-cloud interactions using mean effective radii are shown to be problematic, while conserving re and N of the distribution function (as per Hu and Stamnes, 1993) produces similar cloud evolution as compared to detailed computations. Radiative effects on drop vapor deposition growth can produce drizzle about 30 minutes earlier and is strongly dependent upon cloud top residence time of the parcels. The same set of trajectories assists drizzle production in the radiation and no-radiation cases. Not only is the growth of larger drops enhanced by the radiative effect, but drops with rCRM show a smaller impact of the radiative influence; this is attributed to the spurious production of cloud top supersaturations by Eulerian models (Stevens et al

  19. Effects of seasonal change and experimental warming on the temperature dependence of photosynthesis in the canopy leaves of Quercus serrata.

    Science.gov (United States)

    Yamaguchi, Daisuke P; Nakaji, Tatsuro; Hiura, Tsutom; Hikosaka, Kouki

    2016-10-01

    The effects of warming on the temperature response of leaf photosynthesis have become an area of major concern in recent decades. Although growth temperature (GT) and day length (DL) affect leaf gas exchange characteristics, the way in which these factors influence the temperature dependence of photosynthesis remains uncertain. We established open-top canopy chambers at the canopy top of a deciduous forest, in which average daytime leaf temperature was increased by 1.0 °C. We conducted gas exchange measurements for the canopy leaves of deciduous trees exposed to artificial warming during different seasons. The carbon dioxide assimilation rate at 20 °C (A20) was not affected by warming, whereas that at 25 °C (A25) tended to be higher in leaves exposed to warming. Warming increased the optimal temperature of photosynthesis by increasing the activation energy for the maximum rate of carboxylation. Regression analysis indicated that both GT and DL strongly influenced gas exchange characteristics. Sensitivity analysis revealed that DL affected A without obvious effects on the temperature dependence of A, whereas GT almost maintained constant A20 and strongly influenced the temperature dependence. These results indicate that GT and DL have different influences on photosynthesis; GT and DL affect the 'slope' and intercept' of the temperature dependence of photosynthesis, respectively. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. The effects of dust-haze on mortality are modified by seasons and individual characteristics in Guangzhou, China.

    Science.gov (United States)

    Liu, Tao; Zhang, Yong Hui; Xu, Yan Jun; Lin, Hua Liang; Xu, Xiao Jun; Luo, Yuan; Xiao, Jianpeng; Zeng, Wei Lin; Zhang, Wan Fang; Chu, Cordia; Keogh, Kandice; Rutherford, Shannon; Qian, Zhengmin; Du, Yao Dong; Hu, Mengjue; Ma, Wen Jun

    2014-04-01

    This study aimed to investigate the effects of dust-haze on mortality and to estimate the seasonal and individual-specific modification effects in Guangzhou, China. Mortality, air pollution and meteorological data were collected for 2006-2011. A dust-haze day was defined as daily visibility haze (haze days were associated with increased mortality of 3.4%, 6.8% and 10.4% respectively, at a lag of 0-6 days. This effect was more pronounced during the cold season, for cardiovascular mortality (CVD), respiratory mortality (RESP), in males and people ≥60years. These effects became insignificant after adjustment for PM10. We concluded that dust-haze significantly increased mortality risk in Guangzhou, China, and this effect appears to be dominated by particulate mass and modified by season and individual-specific factors.

  1. Seasonal body size reductions with warming covary with major body size gradients in arthropod species

    DEFF Research Database (Denmark)

    Horne, Curtis R.; Hirst, Andrew G.; Atkinson, David

    2017-01-01

    experience different developmental conditions. Yet, unlike other size patterns, these common seasonal temperature–size gradients have never been collectively analysed. We undertake the largest analysis to date of seasonal temperature-size gradients in multivoltine arthropods, including 102 aquatic...

  2. Competition among warm season C4-cereals influence water use efficiency and competition ratios

    Directory of Open Access Journals (Sweden)

    Amanullah

    2015-12-01

    Full Text Available Water use efficiency (WUE and competition ratio (CR response of three warm season C4-cereals (grasses viz. corn (Zea mays L., cv. Hybrid-5393 VT3, grain sorghum (Sorghum bicolor L. Moench, cv. Hybrid-84G62 PAT, and foxtail millets (Setaria italic, cv. German Strain R in pure and mixed stands under low and high water levels was investigated. The experiment was conducted in pot experiment at Dryland Agriculture Institute, West Texas A&M University, Canyon, Texas, USA, during spring 2010. The objective of this study was to know whether the differences in the competitive ability of different crop species influence WUE or not? The planned mean comparison indicated that the corn WUE was 20, 11, and 6% higher in the mixed stand than in pure stand at 30, 60, and 90 days after emergence (DAE, respectively. The corn plants in pure stand had 91, 72, and 81% higher WUE than the average WUE of sorghum and millets in pure stand at 30, 60, and 90 DAE, respectively. Grain sorghum in pure stand had 70, 32, and 36% higher WUE than that of millets in pure stand at 30, 60, and 90 DAE, respectively. The WUE of three crops in mixed stand was 10 and 8% higher than the two crops mixed stand at the two early stages; but the WUE was 24% less in the three crops mixed stand than the two crops mixed stand at 90 DAE. Corn-mixed stand in two crops (average of corn + sorghum and corn + millets had 78, 74, and 74% higher WUE than the mixed stand of sorghum and millets at 30, 60, and 90 DAE, respectively. Corn and millets mixed stand had 14, 10, and 26% higher WUE than the corn and sorghum mixed stand at 30, 60, and 90 DAE, respectively. The increase in water level decreased WUE at the two late growth stages in all three crop plants. At the early growth stage (30 DAE, WUE increased in all crops at the higher water level. On the basis of CR, corn was found the best competitor, while millets was declared the least competitor in the mixed stands (corn

  3. Seasonal variations in the barrier layer in the South China Sea: characteristics, mechanisms and impact of warming

    Science.gov (United States)

    Zeng, Lili; Wang, Dongxiao

    2016-06-01

    A new observational dataset, the South China Sea Physical Oceanographic Dataset 2014, is examined to investigate the seasonal characteristics, formation mechanisms, and warming effects of the barrier layer (BL) in the South China Sea (SCS). Statistical analysis reveals that the BL is thicker and occurs more frequently during summer and early autumn, while in winter it often coexists with temperature inversions. The formation mechanisms are discussed from the perspective of the controlling regime and the net turbulent energy required for BL evolution. In the initial stage (March-May), the BL is absent due to weak mixing, scarce rainfall and surface warming. In the formation and maintenance stage (June-September), the BL grows in summer and persists into the transition season. The BLs can be classified into three regimes: the flux regime (in the Luzon Strait), the combined regime (in the eastern basin) and the wind regime (southeast of Vietnam). In the attenuation stage (October-February), associated with the winter monsoon, the BL mainly occurs in the combined regime (along the path of western boundary current) and the flux regime (in the southeast corner). The characteristics and generation mechanisms of the temperature inversions near the south Chinese coast, east of Vietnam, and in the Gulf of Thailand are also discussed. Our analysis further demonstrates that the BL has a significant warming effect on upper ocean temperature and heat content in the SCS.

  4. Mortality attributable to seasonal and pandemic influenza, Australia, 2003 to 2009, using a novel time series smoothing approach.

    Directory of Open Access Journals (Sweden)

    David J Muscatello

    Full Text Available BACKGROUND: Official statistics under-estimate influenza deaths. Time series methods allow the estimation of influenza-attributable mortality. The methods often model background, non-influenza mortality using a cyclic, harmonic regression model based on the Serfling approach. This approach assumes that the seasonal pattern of non-influenza mortality is the same each year, which may not always be accurate. AIM: To estimate Australian seasonal and pandemic influenza-attributable mortality from 2003 to 2009, and to assess a more flexible influenza mortality estimation approach. METHODS: We used a semi-parametric generalized additive model (GAM to replace the conventional seasonal harmonic terms with a smoothing spline of time ('spline model' to estimate influenza-attributable respiratory, respiratory and circulatory, and all-cause mortality in persons aged <65 and ≥ 65 years. Influenza A(H1N1pdm09, seasonal influenza A and B virus laboratory detection time series were used as independent variables. Model fit and estimates were compared with those of a harmonic model. RESULTS: Compared with the harmonic model, the spline model improved model fit by up to 20%. In <65 year-olds, the estimated respiratory mortality attributable to pandemic influenza A(H1N1pdm09 was 0.5 (95% confidence interval (CI, 0.3, 0.7 per 100,000; similar to that of the years with the highest seasonal influenza A mortality, 2003 and 2007 (A/H3N2 years. In ≥ 65 year-olds, the highest annual seasonal influenza A mortality estimate was 25.8 (95% CI 22.2, 29.5 per 100,000 in 2003, five-fold higher than the non-statistically significant 2009 pandemic influenza estimate in that age group. Seasonal influenza B mortality estimates were negligible. CONCLUSIONS: The spline model achieved a better model fit. The study provides additional evidence that seasonal influenza, particularly A/H3N2, remains an important cause of mortality in Australia and that the epidemic of pandemic influenza

  5. Climate Warming and Seasonal Precipitation Change Interact to Limit Species Distribution Shifts across Western North America

    OpenAIRE

    Melanie A Harsch; Janneke HilleRisLambers

    2016-01-01

    Using an extensive network of occurrence records for 293 plant species collected over the past 40 years across a climatically diverse geographic section of western North America, we find that plant species distributions were just as likely to shift upwards (i.e., towards higher elevations) as downward (i.e., towards lower elevations)-despite consistent warming across the study area. Although there was no clear directional response to climate warming across the entire study area, there was sig...

  6. 1200 years of warm-season temperature variability in central Scandinavia inferred from tree-ring density

    Science.gov (United States)

    Zhang, Peng; Linderholm, Hans W.; Gunnarson, Björn E.; Björklund, Jesper; Chen, Deliang

    2016-06-01

    Despite the emergence of new high-resolution temperature reconstructions around the world, only a few cover the Medieval Climate Anomaly (MCA). Here we present C-Scan, a new Scots pine tree-ring density-based reconstruction of warm-season (April-September) temperatures for central Scandinavia back to 850 CE, extending the previous reconstruction by 250 years. C-Scan is based on samples collected in a confined mountain region, adjusted for their differences in altitude and local environment, and standardised using the new RSFi algorithm to preserve low-frequency signals. In C-Scan, the warm peak of MCA occurs ca. 1000-1100 CE, and the Little Ice Age (LIA) between 1550 and 1900 CE. Moreover, during the last millennium the coldest decades are found around 1600 CE, and the warmest 10 and 30 years occur in the most recent century. By comparing C-Scan with other millennium-long temperature reconstructions from Fennoscandia, regional differences in multi-decadal temperature variability, especially during the warm period of the last millennium are revealed. Although these differences could be due to methodological reasons, they may indicate asynchronous warming patterns across Fennoscandia. Further investigation of these regional differences and the reasons and mechanisms behind them are needed.

  7. Tradeoffs between global warming and day length on the start of the carbon uptake period in seasonally cold ecosystems.

    Science.gov (United States)

    Wohlfahrt, Georg; Cremonese, Edoardo; Hammerle, Albin; Hörtnagl, Lukas; Galvagno, Marta; Gianelle, Damiano; Marcolla, Barbara; di Cella, Umberto Morra

    2013-12-16

    It is well established that warming leads to longer growing seasons in seasonally cold ecosystems. Whether this goes along with an increase in the net ecosystem carbon dioxide (CO2) uptake is much more controversial. We studied the effects of warming on the start of the carbon uptake period (CUP) of three mountain grasslands situated along an elevational gradient in the Alps. To this end we used a simple empirical model of the net ecosystem CO2 exchange, calibrated and forced with multi-year empirical data from each site. We show that reductions in the quantity and duration of daylight associated with earlier snowmelts were responsible for diminishing returns, in terms of carbon gain, from longer growing seasons caused by reductions in daytime photosynthetic uptake and increases in nighttime losses of CO2. This effect was less pronounced at high, compared to low, elevations, where the start of the CUP occurred closer to the summer solstice when changes in day length and incident radiation are minimal.

  8. Yield Response of Native Warm-Season Forage Grasses to Harvest Intervals and Durations in Mixed Stands

    Directory of Open Access Journals (Sweden)

    Vitalis W. Temu

    2014-02-01

    Full Text Available Tolerance to frequent defoliations is critical for native warm-season grasses managed for forage and wildlife habitat. Yield response of big bluestem (Andropogon gerardii, indiangrass (Sorghastrum nutans, and little bluestem (Schizachyrium scoparium to treatments (30-, 40-, 60-, 90- or 120-d harvest intervals and durations were assessed on early-succession mixed stands. Over three years, phased harvestings were initiated in May, on sets of randomized plots, in five replications to produce one-, two-, and three-year old stands, by the third year. Each plot had marked indiangrass and big bluestem plants which were hand-clipped on harvest-days before whole-plot harvesting. Species yields were greater in first- than second-year plots but not affected by treatments. June–September yields in 2008 were greatest for the 30-d, and more in the first- (8472 kg ha−1 than second-year (7627 kg ha−1 plots. In 2009, yields were also greater in first- than second-year plots but without treatment effects. Recovery yields showed no treatment effect, but were about 67% less for second- compared to first-year plots and much less than plots never harvested before. Data suggest that harvesting similar mixed native warm-season grass stands at 30- to 40-d intervals may provide good hay yields without compromising post-season stand recovery for multiple uses.

  9. Season, sex, age, and education as modifiers of the effects of outdoor air pollution on daily mortality in Shanghai, China: The Public Health and Air Pollution in Asia (PAPA) Study.

    Science.gov (United States)

    Kan, Haidong; London, Stephanie J; Chen, Guohai; Zhang, Yunhui; Song, Guixiang; Zhao, Naiqing; Jiang, Lili; Chen, Bingheng

    2008-09-01

    Various factors can modify the health effects of outdoor air pollution. Prior findings about modifiers are inconsistent, and most of these studies were conducted in developed countries. We conducted a time-series analysis to examine the modifying effect of season, sex, age, and education on the association between outdoor air pollutants [particulate matter air pollution for the warm season (April-September) and cool season (October-March) separately. For total mortality, we examined the association stratified by sex and age. Stratified analysis by educational attainment was conducted for total, cardiovascular, and respiratory mortality. Outdoor air pollution was associated with mortality from all causes and from cardiorespiratory diseases in Shanghai. An increase of 10 mug/m(3) in a 2-day average concentration of PM(10), SO(2), NO(2), and O(3) corresponds to increases in all-cause mortality of 0.25% [95% confidence interval (CI), 0.14-0.37), 0.95% (95% CI, 0.62-1.28), 0.97% (95% CI, 0.66-1.27), and 0.31% (95% CI, 0.04-0.58), respectively. The effects of air pollutants were more evident in the cool season than in the warm season, and females and the elderly were more vulnerable to outdoor air pollution. Effects of air pollution were generally greater in residents with low educational attainment (illiterate or primary school) compared with those with high educational attainment (middle school or above). Season, sex, age, and education may modify the health effects of outdoor air pollution in Shanghai. These findings provide new information about the effects of modifiers on the relationship between daily mortality and air pollution in developing countries and may have implications for local environmental and social policies.

  10. Suicide Mortality Among Retired National Football League Players Who Played 5 or More Seasons.

    Science.gov (United States)

    Lehman, Everett J; Hein, Misty J; Gersic, Christine M

    2016-10-01

    There is current disagreement in the scientific literature about the relationship between playing football and suicide risk, particularly among professional players in the National Football League (NFL). While some research indicates players are at high risk of football-related concussions, which may lead to chronic traumatic encephalopathy and suicide, other research finds such a connection to be speculative and unsupported by methodologically sound research. To compare the suicide mortality of a cohort of NFL players to what would be expected in the general population of the United States. Cohort study; Level of evidence, 3. A cohort of 3439 NFL players with at least 5 credited playing seasons between 1959 and 1988 was assembled for statistical analysis. The vital status for this cohort was updated through 2013. Standardized mortality ratios (SMRs), the ratio of observed deaths to expected deaths, and 95% CIs were computed for the cohort; 95% CIs that excluded unity were considered statistically significant. For internal comparison purposes, standardized rate ratios were calculated to compare mortality results between players stratified into speed and nonspeed position types. Suicide among this cohort of professional football players was significantly less than would be expected in comparison with the United States population (SMR = 0.47; 95% CI, 0.24-0.82). There were no significant differences in suicide mortality between speed and nonspeed position players. There is no indication of elevated suicide risk in this cohort of professional football players with 5 or more credited seasons of play. Because of the unique nature of this cohort, these study results may not be applicable to professional football players who played fewer than 5 years or to college or high school players. © 2016 The Author(s).

  11. In a warming climate, just how predictable are temperature extremes at weather and seasonal time scales?

    CSIR Research Space (South Africa)

    Landman, WA

    2011-10-01

    Full Text Available stream_source_info Landman7_2011.pdf.txt stream_content_type text/plain stream_size 3538 Content-Encoding ISO-8859-1 stream_name Landman7_2011.pdf.txt Content-Type text/plain; charset=ISO-8859-1 In a warming climate... at UK Met Office N9 members SA Japan UKUSA USA Brazil* SA SASA * IBSA-Ocean In use Near future Far future VCM/UTCM ENSEMBLES Strong anthropogenically forced warming trends have been observed over southern Africa and are projected...

  12. Infant mortality, season of birth and the health of older Puerto Rican adults.

    Science.gov (United States)

    McEniry, Mary

    2011-03-01

    The increasing prevalence of heart disease and diabetes among aging populations in low and middle income countries leads to questions regarding the degree to which endogenous early life exposures (exposures in utero) are important determinants of these health conditions. We devised a test using infant mortality (IMR) to verify if season of birth is a good indicator of early life (in utero) conditions that precipitate adult onset of disease. We linked annual IMR at the municipality (municipio) level from the late 1920s to early 1940s with individual birth year and place using a representative sample of older Puerto Rican adults (n = 1447) from the Puerto Rican Elderly: Health Conditions (PREHCO) study. We estimated the effects of season of birth on adult heart disease and diabetes for all respondents and then for respondents according to whether they were born when IMR was lower or higher, controlling for age, gender, obesity, respondent's educational level, adult behavior (smoking and exercise) and other early life exposures (childhood health, knee height and childhood socioeconomic status (SES)). The pattern of effects suggests that season of birth reflects endogenous causes: (1) odds of heart disease and diabetes were strong and significant for those born during the lean season in years when IMR was lower; (2) effects remained consistent even after controlling for other childhood conditions and adult behavior; but (3) no seasonality effects on adult health for adults born when IMR was higher. We conclude that in this population of older Puerto Rican adults there is continued support that the timing of adverse endogenous (in utero) conditions such as poor nutrition and infectious diseases is associated with adult heart disease and diabetes. It will be important to test the validity of these findings in other similar populations in the developing world.

  13. Morbidity, Mortality, and Seasonality of Influenza Hospitalizations in Egypt, November 2007-November 2014

    Science.gov (United States)

    Kandeel, Amr; Labib, Manal; Said, Mayar; El-Refai, Samir; El-Gohari, Amani; Talaat, Maha

    2016-01-01

    Background Influenza typically comprises a substantial portion of acute respiratory infections, a leading cause of mortality worldwide. However, influenza epidemiology data are lacking in Egypt. We describe seven years of Egypt’s influenza hospitalizations from a multi-site influenza surveillance system. Methods Syndromic case definitions identified individuals with severe acute respiratory infection (SARI) admitted to eight hospitals in Egypt. Standardized demographic and clinical data were collected. Nasopharyngeal and oropharyngeal swabs were tested for influenza using real-time reverse transcription polymerase chain reaction and typed as influenza A or B, and influenza A specimens subtyped. Results From November 2007–November 2014, 2,936/17,441 (17%) SARI cases were influenza-positive. Influenza-positive patients were more likely to be older, female, pregnant, and have chronic condition(s) (all p<0.05). Among them, 53 (2%) died, and death was associated with older age, five or more days from symptom onset to hospitalization, chronic condition(s), and influenza A (all p<0.05). An annual seasonal influenza pattern occurred from July–June. Each season, the proportion of the season’s influenza-positive cases peaked during November–May (19–41%). Conclusions In Egypt, influenza causes considerable morbidity and mortality and influenza SARI hospitalization patterns mirror those of the Northern Hemisphere. Additional assessment of influenza epidemiology in Egypt may better guide disease control activities and vaccine policy. PMID:27607330

  14. Coupled prediction of flood response and debris flow initiation during warm- and cold-season events in the Southern Appalachians, USA

    OpenAIRE

    Tao, J.; A. P. Barros

    2014-01-01

    Debris flows associated with rainstorms are a frequent and devastating hazard in the Southern Appalachians in the United States. Whereas warm-season events are clearly associated with heavy rainfall intensity, the same cannot be said for the cold-season events. Instead, there is a relationship between large (cumulative) rainfall events independently of season, and thus hydrometeorological regime, and debris flows. This suggests that the dynamics of subsurface hydrologic proc...

  15. Global warming and mass mortalities of benthic invertebrates in the Mediterranean Sea.

    Science.gov (United States)

    Rivetti, Irene; Fraschetti, Simonetta; Lionello, Piero; Zambianchi, Enrico; Boero, Ferdinando

    2014-01-01

    Satellite data show a steady increase, in the last decades, of the surface temperature (upper few millimetres of the water surface) of the Mediterranean Sea. Reports of mass mortalities of benthic marine invertebrates increased in the same period. Some local studies interpreted the two phenomena in a cause-effect fashion. However, a basin-wide picture of temperature changes combined with a systematic assessment on invertebrate mass mortalities was still lacking. Both the thermal structure of the water column in the Mediterranean Sea over the period 1945-2011 and all documented invertebrate mass mortality events in the basin are analysed to ascertain if: 1- documented mass mortalities occurred under conditions of positive temperature trends at basin scale, and 2- atypical thermal conditions were registered at the smaller spatial and temporal scale of mass mortality events. The thermal structure of the shallow water column over the last 67 years was reconstructed using data from three public sources: MEDAR-MEDATLAS, World Ocean Database, MFS-VOS programme. A review of the mass mortality events of benthic invertebrates at Mediterranean scale was also carried out. The analysis of in situ temperature profiles shows that the Mediterranean Sea changed in a non-homogeneous fashion. The frequency of mass mortalities is increasing. The areas subjected to these events correspond to positive thermal anomalies. Statistically significant temperature trends in the upper layers of the Mediterranean Sea show an increase of up to 0.07°C/yr for a large fraction of the basin. Mass mortalities are consistent with both the temperature increase at basin scale and the thermal changes at local scale, up to 5.2°C. Our research supports the existence of a causal link between positive thermal anomalies and observed invertebrate mass mortalities in the Mediterranean Sea, invoking focused mitigation initiatives in sensitive areas.

  16. Global warming and mass mortalities of benthic invertebrates in the Mediterranean Sea.

    Directory of Open Access Journals (Sweden)

    Irene Rivetti

    Full Text Available Satellite data show a steady increase, in the last decades, of the surface temperature (upper few millimetres of the water surface of the Mediterranean Sea. Reports of mass mortalities of benthic marine invertebrates increased in the same period. Some local studies interpreted the two phenomena in a cause-effect fashion. However, a basin-wide picture of temperature changes combined with a systematic assessment on invertebrate mass mortalities was still lacking. Both the thermal structure of the water column in the Mediterranean Sea over the period 1945-2011 and all documented invertebrate mass mortality events in the basin are analysed to ascertain if: 1- documented mass mortalities occurred under conditions of positive temperature trends at basin scale, and 2- atypical thermal conditions were registered at the smaller spatial and temporal scale of mass mortality events. The thermal structure of the shallow water column over the last 67 years was reconstructed using data from three public sources: MEDAR-MEDATLAS, World Ocean Database, MFS-VOS programme. A review of the mass mortality events of benthic invertebrates at Mediterranean scale was also carried out. The analysis of in situ temperature profiles shows that the Mediterranean Sea changed in a non-homogeneous fashion. The frequency of mass mortalities is increasing. The areas subjected to these events correspond to positive thermal anomalies. Statistically significant temperature trends in the upper layers of the Mediterranean Sea show an increase of up to 0.07°C/yr for a large fraction of the basin. Mass mortalities are consistent with both the temperature increase at basin scale and the thermal changes at local scale, up to 5.2°C. Our research supports the existence of a causal link between positive thermal anomalies and observed invertebrate mass mortalities in the Mediterranean Sea, invoking focused mitigation initiatives in sensitive areas.

  17. Magnitude and pattern of Arctic warming governed by the seasonality of radiative forcing

    NARCIS (Netherlands)

    Bintanja, R.; Krikken, F.

    2016-01-01

    Observed and projected climate warming is strongest in the Arctic regions, peaking in autumn/winter. Attempts to explain this feature have focused primarily on identifying the associated climate feedbacks, particularly the ice-Albedo and lapse-rate feedbacks. Here we use a state-of-The-Art global

  18. Magnitude and pattern of Arctic warming governed by the seasonality of radiative forcing

    NARCIS (Netherlands)

    Bintanja, R.; Krikken, F.

    2016-01-01

    Observed and projected climate warming is strongest in the Arctic regions, peaking in autumn/winter. Attempts to explain this feature have focused primarily on identifying the associated climate feedbacks, particularly the ice-Albedo and lapse-rate feedbacks. Here we use a state-of-The-Art global cl

  19. The contribution of mesoscale convective systems to intense hourly precipitation events during the warm seasons over central East China

    Science.gov (United States)

    He, Zhiwei; Zhang, Qinghong; Sun, Jun

    2016-11-01

    Central East China is an area where both intense hourly precipitation (IHP) events and mesoscale convection systems (MCSs) occur frequently in the warm seasons. Based on mosaics of composite Doppler radar reflectivity and hourly precipitation data during the warm seasons (May to September) from 1 July 2007 to 30 June 2011, the contribution of MCSs to IHP events exceeding 20 mm h-1 over central East China was evaluated. An MCS was defined as a continuous or quasicontinuous band of 40 dBZ reflectivity that extended for at least 100 km in at least one direction and lasted for at least 3 h. It was found that the contribution of MCSs to IHP events was 45% on average over central East China. The largest contribution, more than 80%, was observed along the lower reaches of the Yellow River and in the Yangtze River-Huaihe River valleys. These regions were the source regions of MCSs, or along the frequent tracks of MCSs. There were two daily peaks in the numbers of IHP events: one in the late afternoon and one in the early morning. These peaks were more pronounced in July than in other months. MCSs contributed more to the early-morning IHP event peaks than to the late-afternoon peaks. The contributions of MCSs to IHP events with different intensities exhibited no significant difference, which fluctuated around 50% on average over central East China.

  20. Assessment of long-term monthly and seasonal trends of warm (cold), wet (dry) spells in Kansas, USA

    Science.gov (United States)

    Dokoohaki, H.; Anandhi, A.

    2013-12-01

    A few recent studies have focused on trends in rainfall, temperature, and frost indicators at different temporal scales using centennial weather station data in Kansas; our study supplements this work by assessing the changes in spell indicators in Kansas. These indicators provide the duration between temperature-based (warm and cold) and precipitation-based (wet and dry) spells. For wet (dry) spell calculations, a wet day is defined as a day with precipitation ≥1 mm, and a dry day is defined as one with precipitation ≤1 mm. For warm (cold) spell calculations, a warm day is defined as a day with maximum temperature >90th percentile of daily maximum temperature, and a cold day is defined as a day with minimum temperature spell indicators are calculated: Average Wet Spell Length (AWSL), Dry Spell Length (ADSL), Average Warm Spell Days (AWSD) and Average Cold Spell Days (ACSD) are calculated. Data were provided from 23 centennial weather stations across Kansas, and all calculations were done for four time periods (through 1919, 1920-1949, 1950-1979, and 1980-2009). The definitions and software provided by Expert Team on Climate Change Detection and Indices (ETCCDI) were adapted for application to Kansas. The long- and short-term trends in these indices were analyzed at monthly and seasonal timescales. Monthly results indicate that ADSL is decreasing and AWSL is increasing throughout the state. AWSD and ACSD both showed an overall decreasing trend, but AWSD trends were variable during the beginning of the Industrial Revolution. Results of seasonal analysis revealed that the fall season recorded the greatest increasing trend for ACSD and the greatest decreasing trend for AWSD across the whole state and during all time periods. Similarly, the greatest increasing and decreasing trends occurred in winter for AWSL and ADSL, respectively. These variations can be important indicators of climatic change that may not be represented in mean conditions. Detailed geographical

  1. Sponge mass mortalities in a warming Mediterranean Sea: are cyanobacteria-harboring species worse off?

    Directory of Open Access Journals (Sweden)

    Emma Cebrian

    Full Text Available Mass mortality events are increasing dramatically in all coastal marine environments. Determining the underlying causes of mass mortality events has proven difficult in the past because of the lack of prior quantitative data on populations and environmental variables. Four-year surveys of two shallow-water sponge species, Ircinia fasciculata and Sarcotragus spinosulum, were carried out in the western Mediterranean Sea. These surveys provided evidence of two severe sponge die-offs (total mortality ranging from 80 to 95% of specimens occurring in the summers of 2008 and 2009. These events primarily affected I. fasciculata, which hosts both phototrophic and heterotrophic microsymbionts, while they did not affect S. spinosulum, which harbors only heterotrophic bacteria. We observed a significant positive correlation between the percentage of injured I. fasciculata specimens and exposure time to elevated temperature conditions in all populations, suggesting a key role of temperature in triggering mortality events. A comparative ultrastructural study of injured and healthy I. fasciculata specimens showed that cyanobacteria disappeared from injured specimens, which suggests that cyanobacterial decay could be involved in I. fasciculata mortality. A laboratory experiment confirmed that the cyanobacteria harbored by I. fasciculata displayed a significant reduction in photosynthetic efficiency in the highest temperature treatment. The sponge disease reported here led to a severe decrease in the abundance of the surveyed populations. It represents one of the most dramatic mass mortality events to date in the Mediterranean Sea.

  2. Influence of age, sex and season on morbidity and mortality pattern in goats under village conditions of Madhya Pradesh

    Directory of Open Access Journals (Sweden)

    Amit Kumar Dohare

    2013-12-01

    Full Text Available Aim: To study factors affecting morbidity and mortality pattern in goats in Chambal division of Madhya Pradesh under village conditions. Materials and Methods: The sampling scheme adopted during study was stratified three stage random sampling and data on 549 goats were recorded. Results: The overall morbidity and mortality rate was 20.58% and 10.20% respectively. Proportional mortality due to diarrhoea was highest (35.71% followed by pneumonia (28.57% and miscellaneous causes (12.5%. Pattern of morbidity in male and female was almost similar. Age of goats was the most important factor and accounted for 39.29%, 28.57% and 32.14% mortality in 0-3 month, 6-9 month and above 9 months, respectively. The effect of season on goat mortality was significant (p<0.05.The incidence of mortality were 41.07%, 37.5% and 21.43% in winter, rainy and summer season respectively. Conclusion: In goats mortality was significantly influenced by age groups and suggesting that more care and attention need to be paid in kids 0-3 months age irrespective of season. Mortality due to various diseases in kids and adults could be minimized by identifying the cause and giving proper treatment. [Vet World 2013; 6(6.000: 329-331

  3. Proxy dependence of the temporal pattern of deglacial warming in the tropical South China Sea: toward resolving seasonality

    Science.gov (United States)

    Steinke, Stephan; Kienast, Markus; Groeneveld, Jeroen; Lin, Li-Chuan; Chen, Min-Te; Rendle-Bühring, Rebecca

    2008-04-01

    Sea surface temperatures (SSTs), reconstructed from two Globigerinoides ruber (white) morphotypes (G. ruber sensu stricto, (s.s.); G. ruber sensu lato, (s.l.)) Mg/Ca and alkenones (UK‧37) from core MD01-2390 from the tropical South China Sea (SCS) during the last deglaciation reveal a proxy-dependent discrepancy in the temporal pattern of the deglacial warming. Alkenone data suggest that the deglacial warming is punctuated by a decrease in temperature between ∼17 and 15 ka BP, corroborating previously published alkenone UK‧37 SST records from the southern SCS. Within dating uncertainties, this cooling is coeval with the Heinrich Event 1 (H1) time interval in the North Atlantic region, underscoring the imprints of northern hemisphere forcing on tropical SCS ocean temperatures. The deglacial UK‧37 SST minimum is also paralleled by a maximum in G. ruber morphotype-specific δ18O. G. ruber Mg/Ca SST estimates suggest a morphotype-specific record of SSTs during the time interval of H1. Whereas G. ruber s.s. imply a continuous warming starting around 18 ka BP without any marked response to H1, G. ruber s.l.-based Mg/Ca SST estimates reveal a cooling around ∼17-15 ka BP similar to the H1 interval cooling seen in the alkenone SST record. Similar proxy-dependent differences in deglacial surface water warming have been recorded in the eastern equatorial Pacific, implying a common pattern on both sides of the tropical Pacific Ocean. We submit that this discrepancy could be due to differences in seasonality of planktonic foraminifera G. ruber morphotypes and alkenone-producing algae.

  4. The effect of temperature on different Salmonella serotypes during warm seasons in a Mediterranean climate city, Adelaide, Australia.

    Science.gov (United States)

    Milazzo, A; Giles, L C; Zhang, Y; Koehler, A P; Hiller, J E; Bi, P

    2016-04-01

    Changing trends in foodborne disease are influenced by many factors, including temperature. Globally and in Australia, warmer ambient temperatures are projected to rise if climate change continues. Salmonella spp. are a temperature-sensitive pathogen and rising temperature can have a substantial effect on disease burden affecting human health. We examined the relationship between temperature and Salmonella spp. and serotype notifications in Adelaide, Australia. Time-series Poisson regression models were fit to estimate the effect of temperature during warmer months on Salmonella spp. and serotype cases notified from 1990 to 2012. Long-term trends, seasonality, autocorrelation and lagged effects were included in the statistical models. Daily Salmonella spp. counts increased by 1·3% [incidence rate ratio (IRR) 1·013, 95% confidence interval (CI) 1·008-1·019] per 1 °C rise in temperature in the warm season with greater increases observed in specific serotype and phage-type cases ranging from 3·4% (IRR 1·034, 95% CI 1·008-1·061) to 4·4% (IRR 1·044, 95% CI 1·024-1·064). We observed increased cases of S. Typhimurium PT9 and S. Typhimurium PT108 notifications above a threshold of 39 °C. This study has identified the impact of warm season temperature on different Salmonella spp. strains and confirms higher temperature has a greater effect on phage-type notifications. The findings will contribute targeted information for public health policy interventions, including food safety programmes during warmer weather.

  5. Seasonal survival rates and causes of mortality of Little Owls in Denmark

    DEFF Research Database (Denmark)

    Thorup, Kasper; Pedersen, Dorthe; Sunde, Peter

    2013-01-01

    the causes of current survival rates, we estimated age- and season-specific survival rates and causes of mortality in Danish Little Owls on the basis of ringed birds 1920–2002, radio tagged adult and juveniles 2005–2008 and nest surveys 2006–2008. We estimate that 32 % of all eggs fledge and survive to 2...... strongly associated with anthropogenically modified landscapes, is declining fast and may soon face extinction. The population decline is ultimately associated with reduced survival of independent offspring, but reduced survival rates of adults may possibly contribute to the observed decline. To explore...... weeks post hatching (age of ringing) and 47 %of the nestlings from ringing to fledging. Fifty-five percentage of the radio-tracked fledged young survived to dispersal, i.e. a total survival rate from egg to dispersal of 8 %. Analyses of combined ringing and radio tracking data showed a lower survival...

  6. Trait Acclimation Mitigates Mortality Risks of Tropical Canopy Trees under Global Warming

    NARCIS (Netherlands)

    Sterck, Frank; Anten, Niels P.R.; Schieving, Feike; Zuidema, Pieter A.

    2016-01-01

    There is a heated debate about the effect of global change on tropical forests. Many scientists predict large-scale tree mortality while others point to mitigating roles of CO2 fertilization and – the notoriously unknown – physiological trait acclimation of trees. In this opinion article we provided

  7. Trait Acclimation Mitigates Mortality Risks of Tropical Canopy Trees under Global Warming

    NARCIS (Netherlands)

    Sterck, Frank; Anten, Niels P.R.; Schieving, Feike; Zuidema, Pieter A.

    2016-01-01

    There is a heated debate about the effect of global change on tropical forests. Many scientists predict large-scale tree mortality while others point to mitigating roles of CO2 fertilization and – the notoriously unknown – physiological trait acclimation of trees. In this opinion article we provided

  8. Causes of mortality and temporal patterns in breeding season survival of lesser prairie-chickens in shinnery oak prairies

    Science.gov (United States)

    Grisham, Blake A.; Boal, Clint W.

    2015-01-01

    Baseline survival and mortality data for lesser prairie-chickens (Tympanuchus pallidicinctus) are lacking for shinnery oak (Quercus havardii) prairies. An understanding of the causes and timing of mortalities and breeding season survival in this ecoregion is important because shinnery oak prairies have hotter and drier environmental conditions, as well as different predator communities compared with the northern distribution of the species. The need for this information has become more pressing given the recent listing of the species as threatened under the U.S. Endangered Species Act. We investigated causes of mortality and survival of lesser prairie-chickens during the 6-month breeding season (1 Mar–31 Aug) of 2008–2011 on the Texas Southern High Plains, USA. We recorded 42 deaths of radiotagged individuals, and our results indicated female mortalities were proportionate among avian and mammalian predation and other causes of mortality but survival was constant throughout the 6-month breeding season. Male mortalities were constant across avian and mammalian predation and other causes, but more mortalities occurred in June compared with other months. Male survival also varied by month, and survival probabilities were lower in June–August. We found predation on leks was rare, mortalities from fence collisions were rare, female survival did not decrease during incubation or brood-rearing, and survival was influenced by drought. Our study corroborated recent studies that suggested lesser prairie-chickens are living at the edge of their physiological tolerances to environmental conditions in shinnery oak prairies. As such, lesser prairie-chickens in our study experienced different patterns of mortality and survival that we attributed to hot, dry conditions during the breeding season. Specifically, and converse to other studies on lesser prairie-chicken survival and mortality, drought positively influenced female survival because females did not incubate eggs

  9. Seasonality of mortality and graft failure among kidney transplant recipients in the US - a retrospective study.

    Science.gov (United States)

    Astor, Brad C; Melamed, Michal L; Mandelbrot, Didier A; Djamali, Arjang

    2017-09-04

    Mortality in the general population and in patients on chronic hemodialysis is significantly higher in winter than summer. It is unknown whether such a seasonal difference exists for mortality or graft failure among kidney transplant recipients. We analyzed United Network for Organ Sharing (UNOS) data to assess whether the annual distribution of deaths and graft failures differed significantly from expected. There was significant annual variation in both deaths (n = 52 523) and graft failures (n = 50 301; both P < 0.001). The number of observed deaths exceeded the number expected by 8.9% in winter (P < 0.001), whereas the number of deaths was 4.8% lower than expected in summer (P < 0.01). The pattern was strongest for deaths attributable to cardiovascular disease (n = 11 509; 21.9%). Similarly, there was an excess of graft failures in winter (3.6%; P < 0.01) and a deficit in other seasons (all P ≤ 0.02). This pattern was observed for graft failures due to chronic rejection (P < 0.001) and other causes (P < 0.001), but not for acute rejection (P = 0.28) or recurrent disease (P = 0.27). Potential explanations for this variation include changes in physiologic parameters, changes in medication adherence and other behaviors, or changes in insurance coverage or clinical care. Further studies are necessary to identify specific mechanisms. © 2017 Steunstichting ESOT.

  10. Mass coral mortality under local amplification of 2 °C ocean warming

    Science.gov (United States)

    Decarlo, Thomas M.; Cohen, Anne L.; Wong, George T. F.; Davis, Kristen A.; Lohmann, Pat; Soong, Keryea

    2017-03-01

    A 2 °C increase in global temperature above pre-industrial levels is considered a reasonable target for avoiding the most devastating impacts of anthropogenic climate change. In June 2015, sea surface temperature (SST) of the South China Sea (SCS) increased by 2 °C in response to the developing Pacific El Niño. On its own, this moderate, short-lived warming was unlikely to cause widespread damage to coral reefs in the region, and the coral reef “Bleaching Alert” alarm was not raised. However, on Dongsha Atoll, in the northern SCS, unusually weak winds created low-flow conditions that amplified the 2 °C basin-scale anomaly. Water temperatures on the reef flat, normally indistinguishable from open-ocean SST, exceeded 6 °C above normal summertime levels. Mass coral bleaching quickly ensued, killing 40% of the resident coral community in an event unprecedented in at least the past 40 years. Our findings highlight the risks of 2 °C ocean warming to coral reef ecosystems when global and local processes align to drive intense heating, with devastating consequences.

  11. Mass coral mortality under local amplification of 2 °C ocean warming.

    Science.gov (United States)

    DeCarlo, Thomas M; Cohen, Anne L; Wong, George T F; Davis, Kristen A; Lohmann, Pat; Soong, Keryea

    2017-03-23

    A 2 °C increase in global temperature above pre-industrial levels is considered a reasonable target for avoiding the most devastating impacts of anthropogenic climate change. In June 2015, sea surface temperature (SST) of the South China Sea (SCS) increased by 2 °C in response to the developing Pacific El Niño. On its own, this moderate, short-lived warming was unlikely to cause widespread damage to coral reefs in the region, and the coral reef "Bleaching Alert" alarm was not raised. However, on Dongsha Atoll, in the northern SCS, unusually weak winds created low-flow conditions that amplified the 2 °C basin-scale anomaly. Water temperatures on the reef flat, normally indistinguishable from open-ocean SST, exceeded 6 °C above normal summertime levels. Mass coral bleaching quickly ensued, killing 40% of the resident coral community in an event unprecedented in at least the past 40 years. Our findings highlight the risks of 2 °C ocean warming to coral reef ecosystems when global and local processes align to drive intense heating, with devastating consequences.

  12. Seasonal change in pupation behaviour and pupal mortality in a swallowtail butterfly

    Directory of Open Access Journals (Sweden)

    Stefanescu, C.

    2004-01-01

    Full Text Available Phenotypic plasticity in pupal colour has evolved to render cryptic pupae. Apart from characteristics of the pupation site, the photoperiod experienced by larvae is important in determining pupal colour, long and short photophases eliciting the formation of green and brown pupae, respectively. This seasonal polyphenismis often correlated with developmental pathway, green pupae developing directly and brown pupae entering into diapause. From 1996 to 2000, immature stages of Iphiclides podalirius were monitored on natural hostplants in NE Spain. Larvae were followed to the pupation site and pupal colour, characteristics of the pupation site and the fate of pupae were recorded. Before August, pupae were non-diapausing green while in early August they were dimorphic, after which, they were brown and overwintered. As theory predicts, differences in pupation sites in successive generations were found in relation to pupal colour. Green pupae occurred on the hostplants and brown pupae were found among the leaf litter. Mortality ranged from 14.3 to 100%. Bird predation was the major mortality factor for green pupae and was also important for brown pupae. Results suggest that preference for pupation sites in the litter in diapausing broods evolved to avoid strong bird predation on the hostplants. Preference for sites above ground level in summer generations may have evolved in response to both non-visual (small mammals and visual (avian predators.

  13. Forecasting mortality of road traffic injuries in China using seasonal autoregressive integrated moving average model.

    Science.gov (United States)

    Zhang, Xujun; Pang, Yuanyuan; Cui, Mengjing; Stallones, Lorann; Xiang, Huiyun

    2015-02-01

    Road traffic injuries have become a major public health problem in China. This study aimed to develop statistical models for predicting road traffic deaths and to analyze seasonality of deaths in China. A seasonal autoregressive integrated moving average (SARIMA) model was used to fit the data from 2000 to 2011. Akaike Information Criterion, Bayesian Information Criterion, and mean absolute percentage error were used to evaluate the constructed models. Autocorrelation function and partial autocorrelation function of residuals and Ljung-Box test were used to compare the goodness-of-fit between the different models. The SARIMA model was used to forecast monthly road traffic deaths in 2012. The seasonal pattern of road traffic mortality data was statistically significant in China. SARIMA (1, 1, 1) (0, 1, 1)12 model was the best fitting model among various candidate models; the Akaike Information Criterion, Bayesian Information Criterion, and mean absolute percentage error were -483.679, -475.053, and 4.937, respectively. Goodness-of-fit testing showed nonautocorrelations in the residuals of the model (Ljung-Box test, Q = 4.86, P = .993). The fitted deaths using the SARIMA (1, 1, 1) (0, 1, 1)12 model for years 2000 to 2011 closely followed the observed number of road traffic deaths for the same years. The predicted and observed deaths were also very close for 2012. This study suggests that accurate forecasting of road traffic death incidence is possible using SARIMA model. The SARIMA model applied to historical road traffic deaths data could provide important evidence of burden of road traffic injuries in China. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Shift of spawning season and effects of climate warming on developmental stages of a grayling (Salmonidae).

    Science.gov (United States)

    Wedekind, Claus; Küng, Christoph

    2010-10-01

    River-dwelling fish, such as European graylings (Thymallus thymallus), are susceptible to changes in climate because they can often not avoid suboptimal temperatures, especially during early developmental stages. We analyzed data collected in a 62-year-long (1948-2009) population monitoring program. Male and female graylings were sampled about three times/week during the yearly spawning season in order to follow the development of the population. The occurrence of females bearing ripe eggs was used to approximate the timing of each spawning season. In the last years of the study, spawning season was more than 3 weeks earlier than in the first years. This shift was linked to increasing water temperatures as recorded over the last 39 years with a temperature logger at the spawning site. In early spring water temperatures rose more slowly than in later spring. Thus, embryos and larvae were exposed to increasingly colder water at a stage that is critical for sex determination and pathogen resistance in other salmonids. In summer, however, fry were exposed to increasingly warmer temperatures. The changes in water temperatures that we found embryos, larvae, and fry were exposed to could be contributing to the decline in abundance that has occurred over the last 30-40 years.

  15. Seasonal analysis of the short-term effects of air pollution on daily mortality in Northeast Asia.

    Science.gov (United States)

    Kim, Satbyul Estella; Honda, Yasushi; Hashizume, Masahiro; Kan, Haidong; Lim, Youn-Hee; Lee, Hyewon; Kim, Clara Tammy; Yi, Seung-Muk; Kim, Ho

    2017-01-15

    The constituents and concentrations of pollutants, individual exposures, and biologic responses to air pollution may vary by season and meteorological conditions. However, evidence regarding seasonality of the acute effects of air pollution on mortality is limited and inconsistent. Herein, we examined seasonal patterns in the short-term associations of particulate matter (PM) smaller than 10μm (PM10) with daily mortality in 29 cities of three northeast Asian countries. Stratified time-series models were used to determine whether season altered the effect of PM10 on mortality. This effect was first quantified within each season and at each location using a time-series model, after which city-specific estimates were pooled using a hierarchical Bayesian model. In all data sets, 3,675,348 non-accidental deaths were registered from 1993 to 2009. In Japan, a 10μg/m(3) increase in PM10 was significantly associated with increases in non-accidental mortality of 0.44% (95% confidence interval [CI]: 0.03%, 0.8%) in spring and 0.42% (0.02%, 0.82%) in fall. In South Korea, a 10μg/m(3) increase in PM10 was significantly associated with increases in non-accidental mortality of 0.51% (0.01%, 1.01%) in summer and 0.45% (0.03%, 0.87%) in fall, in cardiovascular disease mortality of 0.96% (0.29%, 1.63%) in fall, and in respiratory disease mortality of 1.57% (0.40%, 2.75%) in fall. In China, a 10μg/m(3) increase in PM10 was associated with increases in non-accidental mortality of 0.33% (0.01%, 0.66%) in summer and 0.41% (0.09%, 0.73%) in winter, in cardiovascular disease mortality of 0.41% (0.08%, 0.74%) in spring and 0.33% (0.02%, 0.64%) in winter, and in respiratory diseases mortality of 0.78% (0.27%, 1.30%) in winter. Our analyses suggest that the acute effect of particulate air pollution could vary seasonally and geographically. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Impact of Seasonal Variant Temperatures and Laboratory Room Ambient Temperature on Mortality of Rats with Ischemic Brain Injury

    Science.gov (United States)

    Gopalakrishanan, Sivakumar; Babu, Mg. Ramesh; Thangarajan, Rajesh; Punja, Dhiren; Jaganath, Vidyadhara Devarunda; Kanth, Akriti B.; Rao, Mohandas

    2016-01-01

    Introduction A popular rat model for hypoperfusion ischemic brain injury is bilateral common carotid artery occlusion (BCCAO). BCCAO surgery when performed in varying geographical locations and during different seasons of the year is reported to have variable mortality rates. Studies have also documented the diminishing influence of Ketamine-Xylazine (KT-XY) on thermoregulatory functions in rodents. Aim To explore the impact of seasonal variant temperatures and laboratory room ambient temperatures on mortality of rats following BCCAO surgery. Materials and Methods The study has two parts: 1 The first part is an analysis of a three year retrospective data to explore the association between the geographical season (hot summer and cold winter) induced laboratory room ambient temperature variations and the mortality rate in KT-XY anaesthetized BCCAO rats. 2. The second part investigated the effect of conditioned laboratory room ambient temperature (CAT) (23-250C) in KT-XY anaesthetized BCCAO group of rats. Rats were divided into 4 groups(n =8/group) as-Normal control, BCCAO and Sham BCCAO where they were all exposed to unconditioned ambient temperature (UCAT) during their surgery and postoperative care. And finally fourth group rats exposed to CAT during the BCCAO surgery and postoperative care. Results Pearson’s chi-square test indicates a significantly high association (p<0.006) between post-BCCAO mortality and hot season of the year. CAT during the hot season reduced the mortality rate (24% less) in post- BCCAO rats compared to the rats of UCAT. Conclusion Despite seasonal variations in temperature, conditioning the laboratory room ambient temperatures to 23–250C, induces hypothermia in KT-XY anaesthetized ischemic brain injured rodents and improves their survival rate. PMID:27190796

  17. Evaluation of an early warning system for heat wave related mortality in Europe: implications for sub-seasonal-to-seasonal forecasting and climate services

    Science.gov (United States)

    Lowe, Rachel; García-Díez, Markel; Ballester, Joan; Creswick, James; Robine, Jean-Marie; Herrmann, François R.; Rodó, Xavier

    2016-04-01

    Heat waves have been responsible for more fatalities in Europe over the past decades than any other extreme weather event. However, temperature-related illnesses and deaths are largely preventable. Reliable sub-seasonal-to-seasonal (S2S) climate forecasts of extreme temperatures could allow for better resource management within heat-health action plans, to protect vulnerable populations and ensure access to preventive measures well in advance. The objective of this study is to assess the extent to which S2S climate forecasts could be incorporated into heat-health action plans, to support timely public health decision-making ahead of imminent heat wave events in Europe. Forecasts of apparent temperature at different lead times (e.g. 1 day, 4 days, 8 days, up to 3 months) were used in a mortality model to produce probabilistic mortality forecasts up to several months ahead of the 2003 heat wave event in Europe. Results were compared to mortality predictions inferred from using observed apparent temperature data in the mortality model. In general, we found a decreasing transition in skill between excellent predictions when using observed temperature, to predictions with no skill when using forecast temperature with lead times greater than one week. However, even at lead-times up to three months, there were some regions in Spain and the United Kingdom where excess mortality was detected with some certainty. This suggests that in some areas of Europe, there is potential for seasonal climate forecasts to be incorporated in localised heat-health action plans. In general, these results show that the performance of this climate service framework is not limited by the mortality model itself, but rather by the predictability of the climate variables, at S2S time scales, over Europe.

  18. The potential effect of global warming on the geographic and seasonal distribution of Phlebotomus papatasi in Southwest Asia

    Energy Technology Data Exchange (ETDEWEB)

    Cross, E.R.; Hyams, K.C. [Naval Medical Research Inst., Bethesda, MD (United States)

    1996-07-01

    The distribution of Phlebotomus papatasi in Southwest Asia is thought to be highly dependent on temperature and relative humidity. A discriminant analysis model based on weather data and reported vector surveys was developed to predict the seasonal and geographic distribution of P. papatasi in this region. To simulate global warming, temperature values for 115 weather stations were increased by 1 {degrees}C, 3{degrees}C, and 5{degrees}C, and the outcome variable coded as unknown in the model. Probability of occurrence values were then predicted for each location with a weather station. Stations with positive probability of occurrence values for May, June, July, and August were considered locations where two or more life cycles of P. papatasi could occur and which could support endemic transmission of leishmaniasis and sandfly fever. Among 115 weather stations, 71 (62%) would be considered endemic with current temperature conditions; 14 (12%) additional station could become endemic with an increase of 1 {degrees}C; 17 (15%) more than a 3{degrees}C increase; and 12 (10%) more (all but one station) with a t{degrees}C increase. In addition to increased geographic distribution, seasonality of disease transmission could be extended throughout 12 months of the year in 7 (6%) locations with at least a 3{degrees}C rise in temperature and in 29 (25%) locations with a 5{degrees}C rise. 15 refs., 4 figs.

  19. Climate and tourism in the Black Forest during the warm season.

    Science.gov (United States)

    Endler, Christina; Matzarakis, Andreas

    2011-03-01

    Climate, climate change and tourism all interact. Part of the public discussion about climate change focusses on the tourism sector, with direct and indirect impacts being of equally high relevance. Climate and tourism are closely linked. Thus, climate is a very decisive factor in choices both of destination and of type of journey (active holidays, wellness, and city tours) in the tourism sector. However, whether choices about destinations or types of trip will alter with climate change is difficult to predict. Future climates can be simulated and projected, and the tendencies of climate parameters can be estimated using global and regional climate models. In this paper, the focus is on climate change in the mountainous regions of southwest Germany - the Black Forest. The Black Forest is one of the low mountain ranges where both winter and summer tourism are vulnerable to climate change due to its southern location; the strongest climatic changes are expected in areas covering the south and southwest of Germany. Moreover, as the choice of destination is highly dependent on good weather, a climatic assessment for tourism is essential. Thus, the aim of this study was to estimate climatic changes in mountainous regions during summer, especially for tourism and recreation. The assessment method was based on human-biometeorology as well as tourism-climatologic approaches. Regional climate simulations based on the regional climate model REMO were used for tourism-related climatic analyses. Emission scenarios A1B and B1 were considered for the time period 2021 to 2050, compared to the 30-year base period of 1971-2000, particularly for the warm period of the year, defined here as the months of March-November. In this study, we quantified the frequency, but not the means, of climate parameters. The study results show that global and regional warming is reflected in an increase in annual mean air temperature, especially in autumn. Changes in the spring show a slight negative

  20. Strong seasonal effect of moderate experimental warming on plankton respiration in a temperate estuarine plankton community

    Science.gov (United States)

    Panigrahi, Satya; Nydahl, Anna; Anton, Peter; Wikner, Johan

    2013-12-01

    Climate change projections forecast a 1.1-6.4 °C global increase in surface water temperature and a 3 °C increase for the Baltic Sea. This study examined the short-term interactive effects of a realistic future temperature increase (3 °C) on pelagic respiration and bacterioplankton growth and phytoplankton photosynthesis in situ. This study was undertaken throughout a full seasonal cycle in the northern Baltic Sea. We found marked positive short-term effects of temperature on plankton respiration but no significant effect on bacterioplankton growth or phytoplankton photosynthesis. Absolute respiration rates remained similar to other comparable environments at the in situ temperature. With the 3 °C temperature increase, respiration rates in situ increased up to 5-fold during the winter and 2-fold during the summer. A maximum seasonal Q10 value of 332 was observed for respiration during the cold winter months (twater ≈ 0 °C), and summer Q10 values were comparatively high (9.1). Q10 values exhibited a significant inverse relationship to water temperature during winter. Our results thereby suggest that plankton respiration in this coastal zone is more temperature sensitive than previously reported. In addition, field data indicated that plankton respiration switched from being temperature limited to being limited by dissolved organic carbon (DOC) after the simulated temperature increase. Assuming that our observations are relevant over longer time scales, climate change may worsen hypoxia, increase CO2 emissions and create a more heterotrophic food web in coastal zones with a high load of riverine DOC.

  1. [Impact of seasons, years El Nino/La Nina and rainfalls on stroke-related morbidity and mortality in Kinshasa].

    Science.gov (United States)

    Kintoki Mbala, F; Longo-Mbenza, B; Mbungu Fuele, S; Zola, N; Motebang, D; Nakin, V; Lueme Lokotola, C; Simbarashe, N; Nge Okwe, A

    2016-02-01

    The significant impact of seasonality and climate change on stroke-related morbidity and mortality is well established, however, some findings on this issue are conflicting. The objective was to determine the impact of gender, age, season, year of admission, temperature, rainfall and El Nino phenomenon on ischemic and hemorrhagic strokes and fatal cases of stroke. The study was carried out at the teaching hospital of Kinshasa, DRC, between January 1998 and December 2004. Rainy and dry seasons, elevated temperatures, indices of rainfalls El Nino years 1998, 2002 and 2004, but La Nina years 1999-2000 and neutral/normal years 2001 and 2003 were defined. Among 470 incident strokes, 34.5% of victims (n=162) died. Traditional seasons (small dry season, small rainy season, great dry season, great rainy season) and temperatures did not significantly (P>0.005) impact on stroke incidence. However, there was a positive association between the decrease in rainfall, El Nino, and incident ischemic strokes, but a significant positive association between the increase in rainfall, La Nina, and incident hemorrhagic strokes. Using logistic regression analysis, age ≥ 60 years (OR: 1.7, 95% CI: 1.2-2.5; P=0.018) and El Nino years (OR: 2, 95% CI: 1.2-3.3; P=0.009) were identified as the independent predictors of fatal strokes. Early warning systems should be developed to predict the impact of seasons and climate variability on stroke morbidity and mortality. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  2. A composite sea surface temperature record of the northern South China Sea for the past 2,500 years: A unique look into seasonality and seasonal climate changes during warm and cold periods

    Science.gov (United States)

    Yan, H.; Soon, W.

    2015-12-01

    High-resolution late Holocene climate records that can resolve seasonality are essential for confirming past climatic dynamics, understanding the late 20th century global warming and predicting future climate. Here a new composite record of the sea surface temperature, SST, variation in the northern South China Sea (SCS) during the late Holocene is constructed by combining seven seasonally-resolved coral and T. gigas Sr/Ca-based SST time-windows with the instrumental SST record from modern interval between 1990 and 2000. This composite multi-proxy marine record, together with the reconstructions from mainland China and tropical western Pacific, indicates that the late Holocene warm periods, the Roman Warm Period (RWP) and Medieval Warm Period (MWP), were prominently imprinted and documented in the climatic and environmental history of the East Asia-Western Pacific region. Meanwhile, substantial and significant SST seasonality variations during the late Holocene were observed in the composite record. The observed increase in seasonality (or amplitude of seasonal cycles) during the cold periods around our study area was probably caused by the different amplitudes between winter versus summer SST variations in northern SCS, with much larger SST variation during winters than during summers for the late Holocene. In addition, the distinctive warm, cold and neutral climatic episodes identified in our northern SCS composite SST record correspond well with other paleo reconstructions from mainland China and especially well with the Northern Hemisphere-wide composites by Moberg et al. (2005) and Ljungqvist (2010). The overall agreement however also calls for more information and insights on how seasonal temperatures and their ranges vary on multidecadal to bicentennial timescales.

  3. Seasonal spatial patterns of projected anthropogenic warming in complex terrain: a modeling study of the western US

    Science.gov (United States)

    Rupp, David E.; Li, Sihan; Mote, Philip W.; Shell, Karen M.; Massey, Neil; Sparrow, Sarah N.; Wallom, David C. H.; Allen, Myles R.

    2016-06-01

    Changes in near surface air temperature (ΔT) in response to anthropogenic greenhouse gas forcing are expected to show spatial heterogeneity because energy and moisture fluxes are modulated by features of the landscape that are also heterogeneous at these spatial scales. Detecting statistically meaningful heterogeneity requires a combination of high spatial resolution and a large number of simulations. To investigate spatial variability of projected ΔT, we generated regional, high-resolution (25-km horizontal), large ensemble (100 members per year), climate simulations of western United States (US) for the periods 1985-2014 and 2030-2059, the latter with atmospheric constituent concentrations from the Representative Concentration Pathway 4.5. Using the large ensemble, 95 % confidence interval sizes for grid-cell-scale temperature responses were on the order of 0.1 °C, compared to 1 °C from a single ensemble member only. In both winter and spring, the snow-albedo feedback statistically explains roughly half of the spatial variability in ΔT. Simulated decreases in albedo exceed 0.1 in places, with rates of change in T per 0.1 decrease in albedo ranging from 0.3 to 1.4 °C. In summer, ΔT pattern in the northwest US is correlated with the pattern of decreasing precipitation. In all seasons, changing lapse rates in the low-to-middle troposphere may account for up to 0.2 °C differences in warming across the western US. Near the coast, a major control of spatial variation is the differential warming between sea and land.

  4. Evaluation of an Early-Warning System for Heat Wave-Related Mortality in Europe: Implications for Sub-seasonal to Seasonal Forecasting and Climate Services.

    Science.gov (United States)

    Lowe, Rachel; García-Díez, Markel; Ballester, Joan; Creswick, James; Robine, Jean-Marie; Herrmann, François R; Rodó, Xavier

    2016-02-06

    Heat waves have been responsible for more fatalities in Europe over the past decades than any other extreme weather event. However, temperature-related illnesses and deaths are largely preventable. Reliable sub-seasonal-to-seasonal (S2S) climate forecasts of extreme temperatures could allow for better short-to-medium-term resource management within heat-health action plans, to protect vulnerable populations and ensure access to preventive measures well in advance. The objective of this study is to assess the extent to which S2S climate forecasts could be incorporated into heat-health action plans, to support timely public health decision-making ahead of imminent heat wave events in Europe. Forecasts of apparent temperature at different lead times (e.g., 1 day, 4 days, 8 days, up to 3 months) were used in a mortality model to produce probabilistic mortality forecasts up to several months ahead of the 2003 heat wave event in Europe. Results were compared to mortality predictions, inferred using observed apparent temperature data in the mortality model. In general, we found a decreasing transition in skill between excellent predictions when using observed temperature, to predictions with no skill when using forecast temperature with lead times greater than one week. However, even at lead-times up to three months, there were some regions in Spain and the United Kingdom where excess mortality was detected with some certainty. This suggests that in some areas of Europe, there is potential for S2S climate forecasts to be incorporated in localised heat-health action plans. In general, these results show that the performance of this climate service framework is not limited by the mortality model itself, but rather by the predictability of the climate variables, at S2S time scales, over Europe.

  5. Protein supplementation of ruminants consuming low-quality cool- or warm-season forage: differences in intake and digestibility.

    Science.gov (United States)

    Bohnert, D W; DelCurto, T; Clark, A A; Merrill, M L; Falck, S J; Harmon, D L

    2011-11-01

    An in situ study (Exp. 1) using 4 ruminally cannulated steers (343 ± 11 kg of BW) in a completely randomized design was used to compare ruminal degradation characteristics of low-quality cool-season (C3; Kentucky bluegrass straw; Poa pratensis; 6.3% CP; DM basis) and warm-season (C4; tallgrass prairie; 5.7% CP; DM basis) forage. Four ruminally cannulated steers (252 ± 8 kg of BW; Exp. 2) and 4 wethers (38 ± 1 kg of BW; Exp. 3) were used in two 2 × 2 factorial arrangements of treatments to determine the influence of supplemental CP (CPSupp; soybean meal; 0.09 and 0.19% of BW, CP basis, for steers and lambs, respectively) on nutrient intake and digestion of C3 and C4 forages. Steers and wethers were allotted to separate 4 × 4 Latin squares that ran simultaneously with 20-d periods. In Exp. 1, C3 had a greater A fraction (fraction of total pool disappearing at a rate too rapid to measure) and effective degradability of DM and NDF compared with C4 (P ruminal liquid retention time (P = 0.02; CPSupp decreased retention by 3.6 h with C4 and by only 0.6 h with C3 forage) and particulate passage rate (P = 0.02; CPSupp increased passage by 46% with C4 and by 10% with C3 forage). As in Exp. 2, a CPSupp × forage interaction (P = 0.01; CPSupp increased digestibility by 18% with C4 and by 7% with C3 forage) was observed with DM digestibility in Exp. 3. In contrast, only N balance (P ruminants are not similar and, more important, that the physiological response of ruminants to protein supplementation of low-quality forage is dependent on forage type.

  6. Corresp onding Relation b etween Warm Season Precipitation Extremes and Surface Air Temp erature in South China

    Institute of Scientific and Technical Information of China (English)

    SUN Wei; LI Jian; YU Ru-Cong

    2013-01-01

    Hourly data of 42 rain gauges over South China during 1966-2005 were used to analyze the corresponding relation between precipitation extremes and surface air temperature in the warm season (May to October). The results show that below 25◦C, both daily and hourly precipitation extremes in South China increase with rising temperature. More extreme events transit to the two-time Clausius-Clapeyron (CC) relationship at lower temperatures. Daily as well as hourly precipitation extremes have a decreasing tendency nearly above 25◦C, among which the decrease of hourly extremes is much more significant. In order to investigate the effects of rainfall durations, hourly precipitation extremes are presented by short duration and long duration precipitation, respectively. Results show that the dramatic decrease of hourly rainfall intensities above 25◦C is mainly caused by short duration precipitation, and long duration precipitation extremes rarely occur in South China when surface air temperature surpasses 28◦C.

  7. A comparative simple method for human bioclimatic conditions applied to seasonally hot/warm cities of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Tejeda Martinez, A. [Universidad Veracruzana, Xalapa, Veracruz (Mexico); Garcia Cueto, O.R. [Universidad Autonoma de Baja California, Mexicali, B.C. (Mexico)

    2002-01-01

    The climate of a region is an environmental resource with important implications for things such as thermal comfort, health and productivity of the population. In this work, the bioclimatic comfort was evaluated for seven seasonally warm/hot cities of Mexico by means of the following current indexes: Discomfort Index, Enthalpy Index and Heat Strain Index. Also, the periods during which it is necessary to use air conditioning in the studied cities were calculated from estimated global radiation and hourly data of temperature and relative humidity which made it possible to establish them with high precision. Finally, the useful of the Heat Strain Index is shown. It is a simple index needing available meteorological data to compare bioclimatic conditions of similar sites. [Spanish] El clima regional tiene implicaciones en el confort, la salud y la productividad de la poblacion. En este articulo se presentan las evaluaciones bioclimaticas comparativas de siete ciudades calidas de Mexico. Se aplicaron los indices bioclimaticos de disconfort, entalpia y esfuerzo frente al calor. Se calcularon los periodos para los cuales es necesario el uso de aire acondicionado, a partir de estimaciones de radiacion solar global y de temperatura y humedad horarias medias mensuales. Finalmente se muestra la utilidad y calidad del Indice de esfuerzo frente al calor, el cual requiere solo de datos climatologicos comunes para poder comparar condiciones bioclimaticas de sitios similares.

  8. Exploratory cloud-resolving simulations of boundary-layer Arctic stratus clouds. Part I: Warm-season clouds

    Science.gov (United States)

    Olsson, Peter Q.; Harrington, Jerry Y.; Feingold, Graham; Cotton, William R.; Kreidenweis, Sonia M.

    Two-dimensional simulations of arctic stratus clouds (ASC) were conducted using a sophisticated cloud-resolving model with explicit microphysics and a two-stream radiative transfer model. The effects of varying cloud condensation nuclei (CCN) concentrations upon the subsequent cloud and its microphysical, radiative and dynamical structure were studied. In this study CCN concentrations were varied within the ranges found in warm-season arctic boundary layers (ABLs) to produce non-drizzling and weakly drizzling stratus decks. Experiments that included all model physics, no-drizzle, and no shortwave radiation were conducted to elucidate the effects of microphysics and radiation on the simulated stratus. Both simulations that did and that did not include the effects of drizzle showed that the higher CCN concentrations produced a cloud with larger reflectivity and absorptivity, but also produced eddies that were weaker than with lower CCN concentrations. Simulations that included the effects of drizzle showed a similar response to changes in CCN concentrations. Simulations with no drizzle produced more vigorous eddies than their drizzling counterparts because cooling due to evaporation below cloud tends to stabilize the ABL. The simulations without the effects of short-wave radiation produced very vigorous eddies that penetrated more deeply into the ABL. In this case, the simulation with higher CCN concentrations produced the most vigorous eddies. This resulted from a subtle interplay of microphysics, radiation, and dynamics.

  9. Seeding method influences warm-season grass abundance and distribution but not local diversity in grassland restoration

    Science.gov (United States)

    Yurkonis, Kathryn A.; Wilsey, Brian J.; Moloney, Kirk A.; Drobney, Pauline; Larson, Diane L.

    2010-01-01

    Ecological theory predicts that the arrangement of seedlings in newly restored communities may influence future species diversity and composition. We test the prediction that smaller distances between neighboring seeds in drill seeded grassland plantings would result in lower species diversity, greater weed abundance, and larger conspecific patch sizes than otherwise similar broadcast seeded plantings. A diverse grassland seed mix was either drill seeded, which places seeds in equally spaced rows, or broadcast seeded, which spreads seeds across the ground surface, into 24 plots in each of three sites in 2005. In summer 2007, we measured species abundance in a 1 m2 quadrat in each plot and mapped common species within the quadrat by recording the most abundant species in each of 64 cells. Quadrat-scale diversity and weed abundance were similar between drilled and broadcast plots, suggesting that processes that limited establishment and controlled invasion were not affected by such fine-scale seed distribution. However, native warm-season (C4) grasses were more abundant and occurred in less compact patches in drilled plots. This difference in C4 grass abundance and distribution may result from increased germination or vegetative propagation of C4 grasses in drilled plots. Our findings suggest that local plant density may control fine-scale heterogeneity and species composition in restored grasslands, processes that need to be further investigated to determine whether seed distributions can be manipulated to increase diversity in restored grasslands.

  10. Coupled prediction of flood response and debris flow initiation during warm and cold season events in the Southern Appalachians, USA

    Directory of Open Access Journals (Sweden)

    J. Tao

    2013-07-01

    Full Text Available Debris flows associated with rainstorms are a frequent and devastating hazard in the Southern Appalachians in the United States. Whereas warm season events are clearly associated with heavy rainfall intensity, the same cannot be said for the cold season events. Instead, there is a relationship between large (cumulative rainfall events independently of season, and thus hydrometeorological regime, and debris flows. This suggests that the dynamics of subsurface hydrologic processes play an important role as a trigger mechanism, specifically through soil moisture redistribution by interflow. The first objective of this study is to investigate this hypothesis. The second objective is to assess the physical basis for a regional coupled flood prediction and debris flow warning system. For this purpose, uncalibrated model simulations of well-documented debris flows in headwater catchments of the Southern Appalachians using a 3-D surface-groundwater hydrologic model coupled with slope stability models are examined in detail. Specifically, we focus on two vulnerable headwater catchments that experience frequent debris flows, the Big Creek and the Jonathan Creek in the Upper Pigeon River Basin, North Carolina, and three distinct weather systems: an extremely heavy summertime convective storm in 2011; a persistent winter storm lasting several days; and a severe winter storm in 2009. These events were selected due to the optimal availability of rainfall observations, availability of detailed field surveys of the landslides shortly after they occurred, which can be used to evaluate model predictions, and because they are representative of events that cause major economic losses in the region. The model results substantiate that interflow is a useful prognostic of conditions necessary for the initiation of slope instability, and should therefore be considered explicitly in landslide hazard assessments. Moreover, the relationships between slope stability and

  11. Coupled prediction of flood response and debris flow initiation during warm and cold season events in the Southern Appalachians, USA

    Science.gov (United States)

    Tao, J.; Barros, A. P.

    2013-07-01

    Debris flows associated with rainstorms are a frequent and devastating hazard in the Southern Appalachians in the United States. Whereas warm season events are clearly associated with heavy rainfall intensity, the same cannot be said for the cold season events. Instead, there is a relationship between large (cumulative) rainfall events independently of season, and thus hydrometeorological regime, and debris flows. This suggests that the dynamics of subsurface hydrologic processes play an important role as a trigger mechanism, specifically through soil moisture redistribution by interflow. The first objective of this study is to investigate this hypothesis. The second objective is to assess the physical basis for a regional coupled flood prediction and debris flow warning system. For this purpose, uncalibrated model simulations of well-documented debris flows in headwater catchments of the Southern Appalachians using a 3-D surface-groundwater hydrologic model coupled with slope stability models are examined in detail. Specifically, we focus on two vulnerable headwater catchments that experience frequent debris flows, the Big Creek and the Jonathan Creek in the Upper Pigeon River Basin, North Carolina, and three distinct weather systems: an extremely heavy summertime convective storm in 2011; a persistent winter storm lasting several days; and a severe winter storm in 2009. These events were selected due to the optimal availability of rainfall observations, availability of detailed field surveys of the landslides shortly after they occurred, which can be used to evaluate model predictions, and because they are representative of events that cause major economic losses in the region. The model results substantiate that interflow is a useful prognostic of conditions necessary for the initiation of slope instability, and should therefore be considered explicitly in landslide hazard assessments. Moreover, the relationships between slope stability and interflow are

  12. Impacts of the Manaus pollution plume on the microphysical properties of Amazonian warm-phase clouds in the wet season

    Science.gov (United States)

    Cecchini, Micael A.; Machado, Luiz A. T.; Comstock, Jennifer M.; Mei, Fan; Wang, Jian; Fan, Jiwen; Tomlinson, Jason M.; Schmid, Beat; Albrecht, Rachel; Martin, Scot T.; Artaxo, Paulo

    2016-06-01

    The remote atmosphere over the Amazon can be similar to oceanic regions in terms of aerosol conditions and cloud type formations. This is especially true during the wet season. The main aerosol-related disturbances over the Amazon have both natural sources, such as dust transport from Africa, and anthropogenic sources, such as biomass burning or urban pollution. The present work considers the impacts of the latter on the microphysical properties of warm-phase clouds by analysing observations of the interactions between the Manaus pollution plume and its surroundings, as part of the GoAmazon2014/5 Experiment. The analysed period corresponds to the wet season (specifically from February to March 2014 and corresponding to the first Intensive Operating Period (IOP1) of GoAmazon2014/5). The droplet size distributions reported are in the range 1 µm ≤ D ≤ 50 µm in order to capture the processes leading up to the precipitation formation. The wet season largely presents a clean background atmosphere characterized by frequent rain showers. As such, the contrast between background clouds and those affected by the Manaus pollution can be observed and detailed. The focus is on the characteristics of the initial microphysical properties in cumulus clouds predominantly at their early stages. The pollution-affected clouds are found to have smaller effective diameters and higher droplet number concentrations. The differences range from 10 to 40 % for the effective diameter and are as high as 1000 % for droplet concentration for the same vertical levels. The growth rates of droplets with altitude are slower for pollution-affected clouds (2.90 compared to 5.59 µm km-1), as explained by the absence of bigger droplets at the onset of cloud development. Clouds under background conditions have higher concentrations of larger droplets (> 20 µm) near the cloud base, which would contribute significantly to the growth rates through the collision-coalescence process. The overall shape

  13. Impacts of the Manaus pollution plume on the microphysical properties of Amazonian warm-phase clouds in the wet season

    Energy Technology Data Exchange (ETDEWEB)

    Cecchini, Micael A.; Machado, Luiz A. T.; Comstock, Jennifer M.; Mei, Fan; Wang, Jian; Fan, Jiwen; Tomlinson, Jason M.; Schmid, Beat; Albrecht, Rachel; Martin, Scot T.; Artaxo, Paulo

    2016-01-01

    The remote atmosphere over the Amazon can be similar to oceanic regions in terms of aerosol conditions and cloud type formations. This is especially true during the wet season. The main aerosol-related disturbances over the Amazon have both natural sources, such as dust transport from Africa, and anthropogenic sources, such as biomass burning or urban pollution. The present work considers the impacts of the latter on the microphysical properties of warm-phase clouds by analysing observations of the interactions between the Manaus pollution plume and its surroundings, as part of the GoAmazon2014/5 Experiment. The analysed period corresponds to the wet season (specifically from February to March 2014 and corresponding to the first Intensive Operating Period (IOP1) of GoAmazon2014/5). The droplet size distributions reported are in the range 1 µm ≤ D≤50 µm in order to capture the processes leading up to the precipitation formation. The wet season largely presents a clean background atmosphere characterized by frequent rain showers. As such, the contrast between background clouds and those affected by the Manaus pollution can be observed and detailed. The focus is on the characteristics of the initial microphysical properties in cumulus clouds predominantly at their early stages. The pollution-affected clouds are found to have smaller effective diameters and higher droplet number concentrations. The differences range from 10 to 40% for the effective diameter and are as high as 1000% for droplet concentration for the same vertical levels. The growth rates of droplets with altitude are slower for pollution-affected clouds (2.90 compared to 5.59 µm km₋1), as explained by the absence of bigger droplets at the onset of cloud development. Clouds under background conditions have higher concentrations of larger droplets (>20 µm) near the cloud base, which would contribute significantly to the growth rates through the collision

  14. Seasonal variations of virus- and nanoflagellate-mediated mortality of heterotrophic bacteria in the coastal ecosystem of subtropical western Pacific

    Directory of Open Access Journals (Sweden)

    A. Y. Tsai

    2013-05-01

    Full Text Available Since viral lysis and nanoflagellate grazing differ in their impact on the aquatic food web, it is important to assess the relative importance of both bacterial mortality factors. In this study, an adapted version of the modified dilution method was applied to simultaneously estimate the impact of both virus and nanoflagellate grazing on the mortality of heterotrophic bacteria. A series of experiments was conducted monthly from April to December 2011 and April to October 2012. The growth rates of bacteria we measured ranged from 0.078 h−1 (April 2011 to 0.42 h−1 (September 2011, indicating that temperature can be important in controlling the seasonal variations of bacterial growth. Furthermore, it appeared that seasonal changes in nanoflagellate grazing and viral lysis could account for 34% to 68% and 13% to 138% of the daily removal of bacterial production, respectively. We suggest that nanoflagellate grazing might play a key role in controlling bacterial biomass and might exceed the impact of viral lysis during the summer period (July to August because of the higher abundance of nanoflagellates at that time. Viral lysis, on the other hand, was identified as the main cause of bacterial mortality between September and December. Based on these findings in this study, the seasonal variations in bacterial abundance we observed can be explained by a scenario in which both growth rates and loss rates (grazing + viral lysis influence the dynamics of the bacteria community.

  15. Chytridiomycosis and seasonal mortality of tropical stream-associated frogs 15 years after introduction of Batrachochytrium dendrobatidis.

    Science.gov (United States)

    Phillott, Andrea D; Grogan, Laura F; Cashins, Scott D; McDonald, Keith R; Berger, Lee; Skerratt, Lee F

    2013-10-01

    Assessing the effects of diseases on wildlife populations can be difficult in the absence of observed mortalities, but it is crucial for threat assessment and conservation. We performed an intensive capture-mark-recapture study across seasons and years to investigate the effect of chytridiomycosis on demographics in 2 populations of the threatened common mist frog (Litoria rheocola) in the lowland wet tropics of Queensland, Australia. Infection prevalence was the best predictor for apparent survival probability in adult males and varied widely with season (0-65%). Infection prevalence was highest in winter months when monthly survival probabilities were low (approximately 70%). Populations at both sites exhibited very low annual survival probabilities (12-15%) but high recruitment (71-91%), which resulted in population growth rates that fluctuated seasonally. Our results suggest that even in the absence of observed mortalities and continued declines, and despite host-pathogen co-existence for multiple host generations over almost 2 decades, chytridiomycosis continues to have substantial seasonally fluctuating population-level effects on amphibian survival, which necessitates increased recruitment for population persistence. Similarly infected populations may thus be under continued threat from chytridiomycosis which may render them vulnerable to other threatening processes, particularly those affecting recruitment success. © 2013 Society for Conservation Biology.

  16. Assessing how seasonal hydrological balance has changed during the warming 20th century in the montane forests of Southeast Asian monsoon region using a stable isotope dendroclimatology approach

    Science.gov (United States)

    Zhu, M.; Stott, L. D.

    2010-12-01

    Tropical montane forests act as water catchment and host of biodiversity in the Southeast Asian monsoon region, and understanding how their hydrological conditions change with global warming is vitally important. Global climate model simulations project enhanced moisture cycle in the tropics, which would cause stronger summer monsoon precipitations, but on the other hand the adiabatic lapse rate would be shifted towards a moister condition (amplification of warming at high elevation), inhibiting dry season orographic lifting cloud/fog formation (lifting cloud base hypothesis), enhancing evapo-transpiration, and leading to a net moisture loss during winter dry season. In this study, we have attempted to investigate how the seasonal moisture balance in Southeast Asia has evolved in response to these influences through the 20th century using the oxygen isotopic composition (δ18O) of subannual tree cellulose samples extracted from the annual rings of pine trees that grow in Doi Chiang Dao, a limestone mountain in northern Thailand. At this location the δ18O of cellulose exhibits distinctive annual cycles of up to 12‰, which is primarily a reflection of both the so-called ‘isotope amount effect’ that is associated with the strong monsoon precipitation during summer wet season and the moisture availability from different sources during winter dry season. We have demonstrated that tree cellulose δ18O could be used as a proxy for regional monsoon strength by showing that the annual mean cellulose δ18O correlate significantly with All India Rainfall, Webster-Yang monsoon index, as well as with both local and regional monsoon precipitation. ENSO is the dominant influence on interannual rainfall variability and this is well expressed in the interannual cellulose δ18O record. Using a 21-year moving window correlation analysis we find a weakening of ENSO influence after 1980, coinciding with the most rapid atmospheric warming. We expect to analyze older trees to

  17. Seasonal variations of all-cause and cause-specific mortality by age, gender, and socioeconomic condition in urban and rural areas of Bangladesh.

    Science.gov (United States)

    Burkart, Katrin; Khan, Mobarak H; Krämer, Alexander; Breitner, Susanne; Schneider, Alexandra; Endlicher, Wilfried R

    2011-08-04

    Mortality exhibits seasonal variations, which to a certain extent can be considered as mid-to long-term influences of meteorological conditions. In addition to atmospheric effects, the seasonal pattern of mortality is shaped by non-atmospheric determinants such as environmental conditions or socioeconomic status. Understanding the influence of season and other factors is essential when seeking to implement effective public health measures. The pressures of climate change make an understanding of the interdependencies between season, climate and health especially important. This study investigated daily death counts collected within the Sample Vital Registration System (VSRS) established by the Bangladesh Bureau of Statistics (BBS). The sample was stratified by location (urban vs. rural), gender and socioeconomic status. Furthermore, seasonality was analyzed for all-cause mortality, and several cause-specific mortalities. Daily deviation from average mortality was calculated and seasonal fluctuations were elaborated using non parametric spline smoothing. A seasonality index for each year of life was calculated in order to assess the age-dependency of seasonal effects. We found distinctive seasonal variations of mortality with generally higher levels during the cold season. To some extent, a rudimentary secondary summer maximum could be observed. The degree and shape of seasonality changed with the cause of death as well as with location, gender, and SES and was strongly age-dependent. Urban areas were seen to be facing an increased summer mortality peak, particularly in terms of cardiovascular mortality. Generally, children and the elderly faced stronger seasonal effects than youths and young adults. This study clearly demonstrated the complex and dynamic nature of seasonal impacts on mortality. The modifying effect of spatial and population characteristics were highlighted. While tropical regions have been, and still are, associated with a marked excess of

  18. Seasonal variations of all-cause and cause-specific mortality by age, gender, and socioeconomic condition in urban and rural areas of Bangladesh

    Directory of Open Access Journals (Sweden)

    Burkart Katrin

    2011-08-01

    Full Text Available Abstract Background Mortality exhibits seasonal variations, which to a certain extent can be considered as mid-to long-term influences of meteorological conditions. In addition to atmospheric effects, the seasonal pattern of mortality is shaped by non-atmospheric determinants such as environmental conditions or socioeconomic status. Understanding the influence of season and other factors is essential when seeking to implement effective public health measures. The pressures of climate change make an understanding of the interdependencies between season, climate and health especially important. Methods This study investigated daily death counts collected within the Sample Vital Registration System (VSRS established by the Bangladesh Bureau of Statistics (BBS. The sample was stratified by location (urban vs. rural, gender and socioeconomic status. Furthermore, seasonality was analyzed for all-cause mortality, and several cause-specific mortalities. Daily deviation from average mortality was calculated and seasonal fluctuations were elaborated using non parametric spline smoothing. A seasonality index for each year of life was calculated in order to assess the age-dependency of seasonal effects. Results We found distinctive seasonal variations of mortality with generally higher levels during the cold season. To some extent, a rudimentary secondary summer maximum could be observed. The degree and shape of seasonality changed with the cause of death as well as with location, gender, and SES and was strongly age-dependent. Urban areas were seen to be facing an increased summer mortality peak, particularly in terms of cardiovascular mortality. Generally, children and the elderly faced stronger seasonal effects than youths and young adults. Conclusion This study clearly demonstrated the complex and dynamic nature of seasonal impacts on mortality. The modifying effect of spatial and population characteristics were highlighted. While tropical regions have

  19. SEASONAL AND INTER-ANNUAL VARIABILITY OF THE SOUTH CHINA SEA WARM POOL AND ITS RELATION TO THE SOUTH CHINA SEA MONSOON ONSET

    Institute of Scientific and Technical Information of China (English)

    赵永平; 陈永利

    2001-01-01

    The South China Sea warm pool interacts vigorously with the summer monsoon which is active in the region. However, there has not been a definition concerning the former warm pool which is as specific as that for the latter. The seasonal and inter-annual variability of the South China Sea warm pool and its relations to the South China Sea monsoon onset were analyzed using Levitus and NCEP/NCAR OISST data. The results show that, the seasonal variability of the South China Sea warm pool is obvious, which is weak in winter, develops rapidly in spring, becomes strong and extensive in summer and early autumn, and quickly decays from mid-autumn. The South China Sea warm pool is 55 m in thickness in the strongest period and its axis is oriented from southwest to northeast with the main section locating along the western offshore steep slope of northern Kalimantan-Palawan Island. For the warm pools in the South China Sea, west Pacific and Indian Ocean, the oscillation, which is within the same large scale air-sea coupling system, is periodic around 5 years. There are additional oscillations of about 2.5 years and simultaneous inter-annual variations for the latter two warm pools. The intensity of the South China Sea warm pool varies by a lag of about 5 months as compared to the west Pacific one. The result also indicates that the inter-annual variation of the intensity index is closely related with the onset time of the South China Sea monsoon. When the former is persistently warmer (colder) in preceding winter and spring, the monsoon in the South China Sea usually sets in on a later (earlier) date in early summer. The relation is associated with the activity of the high pressure over the sea in early summer. An oceanic background is given for the prediction of the South China Sea summer monsoon, though the mechanism through which the warm pool and eventually the monsoon are affected remains unclear.

  20. GIS Assessment of the PM10, PM2.5 and PM1.0 Concentrations in Urban Area of Tehran in Warm and Cold Seasons

    Science.gov (United States)

    Halek, F.; Kavousi-rahim, A.

    2014-10-01

    In recent years, atmospheric models, such as GIS, are used for environmental analysis and the related management for supporting the environmental decision makers in different countries. In this study, concentrations of PM10, PM2.5 and PM1.0 are found in urban areas of Tehran in warm and cold seasons and the data applied in the related modelling, using Arc-GIS. For this purpose, samples were collected from 42 sites in an 18 km2 region located in the west and central parts of Tehran. The mean concentrations of PM1.0, PM2.5 and PM10 are found to be 13.14 μg/m3, 22.67 μg/m3 and 95.72 μg/m3 in the warm season; and 50.12 μg/m3, 70.72 μg/m3 and 193.86 μg/m3 in the cold season respectively. In this paper, with the aid of GIS, concentrations of the suspended particles were measured in 22 major hospitals, the patients in which are in contact with these pollutants. It was found the concentrations of the suspended particles were much higher in the cold season.

  1. GIS ASSESSMENT OF THE PM10, PM2.5 AND PM1.0 CONCENTRATIONS IN URBAN AREA OF TEHRAN IN WARM AND COLD SEASONS

    Directory of Open Access Journals (Sweden)

    F. Halek

    2014-10-01

    Full Text Available In recent years, atmospheric models, such as GIS, are used for environmental analysis and the related management for supporting the environmental decision makers in different countries. In this study, concentrations of PM10, PM2.5 and PM1.0 are found in urban areas of Tehran in warm and cold seasons and the data applied in the related modelling, using Arc-GIS. For this purpose, samples were collected from 42 sites in an 18 km2 region located in the west and central parts of Tehran. The mean concentrations of PM1.0, PM2.5 and PM10 are found to be 13.14 μg/m3, 22.67 μg/m3 and 95.72 μg/m3 in the warm season; and 50.12 μg/m3, 70.72 μg/m3 and 193.86 μg/m3 in the cold season respectively. In this paper, with the aid of GIS, concentrations of the suspended particles were measured in 22 major hospitals, the patients in which are in contact with these pollutants. It was found the concentrations of the suspended particles were much higher in the cold season.

  2. Development of new techniques of using irradiation in the genetic improvement of warm season grasses, the assessment of their genetic and cytogenetic effects and biomass production from grass. Annual progress report, November 1, 1979 to October 31, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Burton, G W; Hanna, W W

    1980-01-01

    New techniques are described for using irradiation and chemical mutagens in the genetic improvement of several warm season grasses. Genetic and cytogenetic effects of these treatments are also being studied. (ACR)

  3. Seasonal Patterns of Sporophyte Growth, Fertility, Fouling, and Mortality of Saccharina latissima in Skagerrak, Norway: Implications for Forest Recovery

    Directory of Open Access Journals (Sweden)

    Guri Sogn Andersen

    2011-01-01

    Full Text Available On the Skagerrak coast the kelp Saccharina latissima has suffered severe stand reductions over the last decade, resulting in loss of important habitats. In the present study, healthy kelp plants were transplanted into four deforested areas and their patterns of growth, reproduction, and survival were monitored through subsequent seasons. Our main objective was to establish whether the kelp plants were able to grow and mature in deforested areas. We observed normal patterns of growth and maturation at all study sites. However, heavy fouling by epiphytes occurred each summer, followed by high kelp mortality. The study shows that the seasonal variations and the life stage timing of S. latissima make formation of self-sustainable populations impossible in the present environment. Most noteworthy, we suggest that fouling by epiphytes is involved in the lack of kelp forest recovery in Skagerrak, Norway.

  4. Characterization of water quality and suspended sediment during cold-season flows, warm-season flows, and stormflows in the Fountain and Monument Creek watersheds, Colorado, 2007–2015

    Science.gov (United States)

    Miller, Lisa D.; Stogner, Sr., Robert W.

    2017-09-01

    From 2007 through 2015, the U.S. Geological Survey, in cooperation with Colorado Springs City Engineering, conducted a study in the Fountain and Monument Creek watersheds, Colorado, to characterize surface-water quality and suspended-sediment conditions for three different streamflow regimes with an emphasis on characterizing water quality during storm runoff. Data collected during this study were used to evaluate the effects of stormflows and wastewater-treatment effluent discharge on Fountain and Monument Creeks in the Colorado Springs, Colorado, area. Water-quality samples were collected at 2 sites on Upper Fountain Creek, 2 sites on Monument Creek, 3 sites on Lower Fountain Creek, and 13 tributary sites during 3 flow regimes: cold-season flow (November–April), warm-season flow (May–October), and stormflow from 2007 through 2015. During 2015, additional samples were collected and analyzed for Escherichia coli (E. coli) during dry weather conditions at 41 sites, located in E. coli impaired stream reaches, to help identify source areas and scope of the impairment.Concentrations of E. coli, total arsenic, and dissolved copper, selenium, and zinc in surface-water samples were compared to Colorado in-stream standards. Stormflow concentrations of E. coli frequently exceeded the recreational use standard of 126 colonies per 100 milliliters at main-stem and tributary sites by more than an order of magnitude. Even though median E. coli concentrations in warm-season flow samples were lower than median concentrations in storm-flow samples, the water quality standard for E. coli was still exceeded at most main-stem sites and many tributary sites during warm-season flows. Six samples (three warm-season flow and three stormflow samples) collected from Upper Fountain Creek, upstream from the confluence of Monument Creek, and two stormflow samples collected from Lower Fountain Creek, downstream from the confluence with Monument Creek, exceeded the acute water

  5. What drives cold-related excess mortality in a south Asian tropical monsoon climate-season vs. temperatures and diurnal temperature changes

    Science.gov (United States)

    Burkart, Katrin; Kinney, Patrick L.

    2016-12-01

    Despite the tropical climate which is characterized by generally high temperatures and persistent mild temperatures during the winter season, Bangladesh, along with many other tropical countries, experiences strong winter and cold-related excess mortality. The objective of this paper was to analyse the nature of these cold effects and understand the role of season vs. temperature and diurnal changes in temperature. For approaching these questions, we applied different Poisson regression models. Temperature as well as diurnal temperature range (DTR) were considered as predictor variables. Different approaches to seasonality adjustment were evaluated and special consideration was given to seasonal differences in atmospheric effects. Our findings show that while seasonality adjustment affected the magnitude of cold effects, cold-related mortality persisted regardless the adjustment approach. Strongest effects of low temperatures were observed at the same day (lag 1) with an increase of 1.7% (95% CI = 0.86-2.54%) per 1 °C decrease in temperature during the winter season. Diurnal temperature affected mortality with increasing levels at higher ranges. Mortality increased with 0.97% (95% CI = 0.17-1.75%) when looking at the entire season, but effects of DTR were not significant during winter when running a seasonal model. Different from effects observed in the mid-latitudes, cold effects in Bangladesh occurred on a very short time scale highlighting the role of temperature versus season. Insufficient adaptation with regard to housing and clothing might lead to such cold-related increases in mortality despite rather moderate temperature values. Although the study did not demonstrate an effect of DTR during the cold season, the strong correlation with (minimum) temperature might cause a multicollinearity problem and effects are difficult to attribute to one driver.

  6. Trade-offs between global warming and day length on the start of the carbon uptake period in seasonally cold ecosystems

    Science.gov (United States)

    Wohlfahrt, Georg; Cremonese, Edoardo; Hammerle, Albin; Hörtnagl, Lukas; Galvagno, Marta; Gianelle, Damiano; Marcolla, Barbara; Cella, Umberto Morra

    2013-12-01

    is well established that warming leads to longer growing seasons in seasonally cold ecosystems. Whether this goes along with an increase in the net ecosystem carbon dioxide (CO2) uptake is much more controversial. We studied the effects of warming on the start of the carbon uptake period (CUP) of three mountain grasslands situated along an elevational gradient in the Alps. To this end, we used a simple empirical model of the net ecosystem CO2 exchange, calibrated, and forced with multiyear empirical data from each site. We show that reductions in the quantity and duration of daylight associated with earlier snowmelts were responsible for diminishing returns, in terms of carbon gain, from longer growing seasons caused by reductions in daytime photosynthetic uptake and increases in nighttime losses of CO2. This effect was less pronounced at high, compared to low, elevations, where the start of the CUP occurred closer to the summer solstice when changes in day length and incident radiation are minimal.

  7. Trend and Seasonal Patterns of Injuries and Mortality Due to Motorcyclists Traffic Accidents; A Hospital-Based Study.

    Science.gov (United States)

    Hosseinpour, Marjan; Mohammadian-Hafshejani, Abdollah; Esmaeilpour Aghdam, Mohammad; Mohammadian, Mahdi; Maleki, Farzad

    2017-01-01

    To investigate trend and seasonal pattern of occurrence and mortality of motorcycle accidents in patients referred to hospitals of Isfahan. This cross-sectional study was carried out using traffic accidents data of Isfahan province, extracted from Ministry of Health (MOH) database from 2006 to 2010. During the study period, 83648 people injured due to motorcycle traffic accidents were referred to hospitals, all of them entered in the study. Logistic regression model was used to calculate the hospital mortality odds ratio, and Cochrane-Armitage test was used for assessment of linear trend. During the study period, the hospital admission for motorcycle accident was 83,648 and 89.3% (74743) of them were men. Mean age in accidents time was 26.41±14.3 years. The injuries and death sex ratio were 8.4 and 16.9, respectively. Lowest admission rate was during autumn and highest during summer. The injury mortality odds ratio was 1.01 (CI 95% 0.73-1.39) in the Spring, 1.34 (CI95% 1.01-1.79) in summer and 1.17 (CI95% 0.83-1.63). It was also calculated to be 2.51 (CI95% 1.36-4.64) in age group 40-49, 2.39 (CI95% 1.51-5.68) in 50-59 and 4.79 (CI95% 2.49-9.22) in 60-69 years. The mortality odds ratio was 3.53 (CI95% 2.77-4.5) in rural place, 1.33 (CI95% 1.15-1.54) in men, and 2.44 (CI95% 2.09-2.85) in the road out of town and village. In addition, trend of motorcycle accidents mortality was increasing (paccidents injuries are more common in men, summer, young age and rural roads. These high risk groups need more attention, care and higher training.

  8. The Effect of Passive Design Strategies on Thermal Performance of Female Secondary School Buildings during Warm Season in Hot Dry Climate

    Directory of Open Access Journals (Sweden)

    Sahar eZahiri

    2016-03-01

    Full Text Available This paper describes a series of field studies and simulation analysis to improve the thermal performance of school buildings in the city of Tehran in Iran during warm season. The field studies used on-site measurement and questionnaire-based survey in the warm spring season in a typical female secondary school building. The on-site monitoring assessed the indoor air temperature and humidity levels of six classrooms while the occupants completed questionnaires covering their thermal sensations and thermal preferences. Moreover, thermal simulation analysis was also carried out to evaluate and improve the thermal performance of the classrooms based on the students’ thermal requirements and passive design strategies. In this study, the environmental design guidelines for female secondary school buildings were introduced for the hot and dry climate of Tehran, using passive design strategies. The study shows that the application of passive design strategies including south and south-east orientation, 10cm thermal insulation in wall and 5cm in the roof, and the combination of 30cm side fins and overhangs as a solar shading devices, as well as all-day ventilation strategy and the use of thermal mass materials with 25cm-30cm thickness, has considerable impact on indoor air temperatures in warm season in Tehran and keeps the indoor environment in an acceptable thermal condition. The results of the field studies also indicated that most of the occupants found their thermal environment not to be comfortable and the simulation results showed that passive design techniques had a significant influence on the indoor air temperature and can keep it in an acceptable range based on the female students’ thermal requirement. Therefore, in order to enhance the indoor environment and to increase the learning performance of the students, it is necessary to use the appropriate passive design strategies, which also reduce the need for mechanical systems and

  9. EFFECT OF PRE-COOLING ON REPEAT-SPRINT PERFORMANCE IN SEASONALLY ACCLIMATISED MALES DURING AN OUTDOOR SIMULATED TEAM-SPORT PROTOCOL IN WARM CONDITIONS

    Directory of Open Access Journals (Sweden)

    Carly J. Brade

    2013-09-01

    Full Text Available Whether precooling is beneficial for exercise performance in warm climates when heat acclimatised is unclear. The purpose of this study was to determine the effect of precooling on repeat-sprint performance during a simulated team-sport circuit performed outdoors in warm, dry field conditions in seasonally acclimatised males (n = 10. They performed two trials, one with precooling (PC; ice slushy and cooling jacket and another without (CONT. Trials began with a 30-min baseline/cooling period followed by an 80 min repeat-sprint protocol, comprising 4 x 20-min quarters, with 2 x 5-min quarter breaks and a 10-min half-time recovery/cooling period. A clear and substantial (negative; PC slower effect was recorded for first quarter circuit time. Clear and trivial effects were recorded for overall circuit time, third and fourth quarter sprint times and fourth quarter best sprint time, otherwise unclear and trivial effects were recorded for remaining performance variables. Core temperature was moderately lower (Cohen's d=0.67; 90% CL=-1.27, 0.23 in PC at the end of the precooling period and quarter 1. No differences were found for mean skin temperature, heart rate, thermal sensation, or rating of perceived exertion, however, moderate Cohen's d effect sizes suggested a greater sweat loss in PC compared with CONT. In conclusion, repeat- sprint performance was neither clearly nor substantially improved in seasonally acclimatised players by using a combination of internal and external cooling methods prior to and during exercise performed in the field in warm, dry conditions. Of practical importance, precooling appears unnecessary for repeat-sprint performance if athletes are seasonally acclimatised or artificially acclimated to heat, as it provides no additional benefit

  10. Association of Seasonal Climate Variability and Age-Specific Mortality in Northern Sweden before the Onset of Industrialization

    Directory of Open Access Journals (Sweden)

    Joacim Rocklöv

    2014-07-01

    Full Text Available Background and aims: Little is known about health impacts of climate in pre-industrial societies. We used historical data to investigate the association of temperature and precipitation with total and age-specific mortality in Skellefteå, northern Sweden, between 1749 and 1859. Methods: We retrieved digitized aggregated population data of the Skellefteå parish, and monthly temperature and precipitation measures. A generalized linear model was established for year to year variability in deaths by annual and seasonal average temperature and cumulative precipitation using a negative binomial function, accounting for long-term trends in population size. The final full model included temperature and precipitation of all four seasons simultaneously. Relative risks (RR with 95% confidence intervals (CI were calculated for total, sex- and age-specific mortality. Results: In the full model, only autumn precipitation proved statistically significant (RR 1.02; CI 1.00–1.03, per 1cm increase of autumn precipitation, while winter temperature (RR 0.98; CI 0.95–1.00, per 1 °C increase in temperature and spring precipitation (RR 0.98; CI 0.97–1.00 per 1 cm increase in precipitation approached significance. Similar effects were observed for men and women. The impact of climate variability on mortality was strongest in children aged 3–9, and partly also in older children. Infants, on the other hand, appeared to be less affected by unfavourable climate conditions. Conclusions: In this pre-industrial rural region in northern Sweden, higher levels of rain during the autumn increased the annual number of deaths. Harvest quality might be one critical factor in the causal pathway, affecting nutritional status and susceptibility to infectious diseases. Autumn rain probably also contributed to the spread of air-borne diseases in crowded living conditions. Children beyond infancy appeared most vulnerable to climate impacts.

  11. Age, growth, mortality and reproductive seasonality of jolthead porgy, Calamus bajonado, from Florida waters

    Directory of Open Access Journals (Sweden)

    Michael L. Burton

    2017-09-01

    Full Text Available Ages of jolthead porgy (Calamus bajonado Schneider 1801 (n = 635 from Florida commercial and recreational fisheries from 2008–2016 were determined using sectioned sagittal otoliths. We determined, using edge-type analysis, that opaque zones were annular, forming March–June (peaking in April. Jolthead porgy ranged from 1–13 years, and the largest fish measured 680 mm TL (total length, mm. Body size relationships for jolthead porgy were TL = 1.09FL + 20.44 (n = 622, r2 = 0.99, FL = 0.90 TL –14.26 (n = 622, r2 = 0.99, and W = 1.1 × 10−5 TL3.06 (n = 577, where W is total weight (grams, g and FL is fork length (mm. The von Bertalanffy growth equation for jolthead porgy was Lt = 737(1 − e−0.14(t+2.02 (n = 635. Point estimate of natural mortality was M = 0.32, while age-specific estimates of M ranged from 0.58–0.17 y−1 for ages 1–13. Catch curve analysis estimated the instantaneous rate of total mortality Z = 0.70, while instantaneous rate of fishing mortality F was 0.38. Macroscopic staging of female gonads indicated the presence of hydrated oocytes from December–March, and GSI data indicates that peak spawning in females occurs during March. This study presents the first published findings of life history parameters for jolthead porgy from the Atlantic waters off the southeastern United States.

  12. A Possible Cause for Different Diurnal Variations of Warm Season Rainfall as Shown in Station Observations and TRMM 3B42 Data over the Southeastern Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    CHEN Haoming; YUAN Weihua; LI Jian; YU Rucong

    2012-01-01

    In this study,records from a 3-yr intensified observational experiment at eight stations along the hillside of Seqilashan over the southeastern Tibetan Plateau were analyzed and combined with records at 28 routine observation stations in the Chinese National Meteorological Station Network to investigate the influences of station location on the different diurnal rainfall variations between station records and Tropical Rainfall Measuring Mission (TRMM) data products.The results indicate that the diurnal variation of warm season rainfall is closely related to location of stations.The prevailing nocturnal rainfall peak in observations at routine stations can be largely attributed to the relatively lower location of the stations,which are mostly situated in valleys.The records at Seqilashan stations on hillsides revealed an evident diurnal afternoon peak of warm season rainfall,similar to that indicated by TRMM data.The different diurnal phases between valley and hillside stations are closely related to the orographically induced regional circulations caused by the complex topography over the Tibetan Plateau.The results of this study indicate that the prevailing nocturnal rainfall associated with the relatively lower location of routine observation stations can partially explain the diurnal rainfall variations between observation station records and TRMM data.

  13. Seasonal abundance and mortality of Oebalus poecilus (Dallas) (Hemiptera: Pentatomidae) in a hibernation refuge

    OpenAIRE

    R. S. S. Santos; L. R. Redaelli; DIEFENBACH L. M. G.; ROMANOWSKI,H. P.; Prando,H. F.; R. C. Antochevis

    2006-01-01

    Oebalus poecilus (Dallas) is an important pest affecting irrigated rice in Rio Grande do Sul, Brazil. It hibernates during the coldest months of the year in refuges such as bamboo litter. This study examined O. poecilus hibernation to determine the causes of mortality during this period. The study was conducted in a 140 m² bamboo plantation located in a rice-growing area in Eldorado do Sul County (30° 02’ S and 51° 23’ W), RS. During June 2000 to April 2002, 63 samples of litter were taken in...

  14. A 1500 yr warm-season temperature record from varved Lago Plomo, Northern Patagonia (47° S) and implications for the Pacific Decadal Oscillation (PDO)

    Science.gov (United States)

    Elbert, J.; Jacques-Coper, M.; Van Daele, M.; Urrutia, R.; Grosjean, M.

    2013-04-01

    High-resolution records of calibrated proxy data for the past 2000 yr are fundamental to place current changes into the context of pre-industrial natural forced and unforced variability. Although the need for regional spatially explicit comprehensive reconstructions is widely recognized, the proxy data sources are still scarce, particularly for the Southern Hemisphere and South America. We provide a 1500 yr long warm season temperature record from varved Lago Plomo, a proglacial lake of the Northern Patagonian Ice field in southern Chile (46°59' S, 72°52' W, 203 m). The thickness of the bright summer sediment layer relative to the dark winter layer (measured as total brightness; % reflectance 400-730 nm) is calibrated against warm season SONDJF temperature (1900-2009; r = 0.58, p(aut) = 0.056, RE = 0.52; CE = 0.15, RMSEP = 0.28 °C; five-year triangular filtered data). In Lago Plomo, warm summer temperatures lead to enhanced glacier melt and suspended sediment transport, which results in a thicker light summer layer and to brighter sediments (% total brightness). Although Patagonia shows pronounced regional differences in decadal temperature trends and variability, the 1500 yr temperature reconstruction from Lago Plomo compares favourably with other regional/continental temperature records but also emphasizes significant regional differences for which no data and information existed so far. The reconstruction shows pronounced sub-decadal-multi-decadal variability with cold phases in the 5th, 7th and 9th centuries, during parts of the Little Ice Age chronozone (16th and 18th centuries) and in the beginning of the 20th century. The most prominent warm phase is the 19th century which is as warm as the second half of the 20th century, emphasizing a delayed recent global warming in the Southern Hemisphere. The comparison between winter precipitation and summer temperature (inter-seasonal coupling) from Lago Plomo reveals alternating phases with parallel and

  15. A 1500 yr warm-season temperature record from varved Lago Plomo, Northern Patagonia (47° S and implications for the Pacific Decadal Oscillation (PDO

    Directory of Open Access Journals (Sweden)

    J. Elbert

    2013-04-01

    Full Text Available High-resolution records of calibrated proxy data for the past 2000 yr are fundamental to place current changes into the context of pre-industrial natural forced and unforced variability. Although the need for regional spatially explicit comprehensive reconstructions is widely recognized, the proxy data sources are still scarce, particularly for the Southern Hemisphere and South America. We provide a 1500 yr long warm season temperature record from varved Lago Plomo, a proglacial lake of the Northern Patagonian Ice field in southern Chile (46°59' S, 72°52' W, 203 m. The thickness of the bright summer sediment layer relative to the dark winter layer (measured as total brightness; % reflectance 400–730 nm is calibrated against warm season SONDJF temperature (1900–2009; r = 0.58, p(aut = 0.056, RE = 0.52; CE = 0.15, RMSEP = 0.28 °C; five-year triangular filtered data. In Lago Plomo, warm summer temperatures lead to enhanced glacier melt and suspended sediment transport, which results in a thicker light summer layer and to brighter sediments (% total brightness. Although Patagonia shows pronounced regional differences in decadal temperature trends and variability, the 1500 yr temperature reconstruction from Lago Plomo compares favourably with other regional/continental temperature records but also emphasizes significant regional differences for which no data and information existed so far. The reconstruction shows pronounced sub-decadal–multi-decadal variability with cold phases in the 5th, 7th and 9th centuries, during parts of the Little Ice Age chronozone (16th and 18th centuries and in the beginning of the 20th century. The most prominent warm phase is the 19th century which is as warm as the second half of the 20th century, emphasizing a delayed recent global warming in the Southern Hemisphere. The comparison between winter precipitation and summer temperature (inter-seasonal coupling from Lago Plomo reveals alternating phases with

  16. Season exerts differential effects of ocean acidification and warming on growth and carbon metabolism of the seaweed Fucus vesiculosus in the western Baltic Sea

    Directory of Open Access Journals (Sweden)

    Angelika eGraiff

    2015-12-01

    Full Text Available Warming and acidification of the oceans as a consequence of increasing CO2-concentrations occur at large scales. Numerous studies have shown the impact of single stressors on individual species. However, studies on the combined effect of multiple stressors on a multi-species assemblage, which is ecologically much more realistic and relevant, are still scarce. Therefore, we orthogonally crossed the two factors warming and acidification in mesocosm experiments and studied their single and combined impact on the brown alga Fucus vesiculosus associated with its natural community (epiphytes and mesograzers in the Baltic Sea in all seasons (from April 2013 to April 2014. We superimposed our treatment factors onto the natural fluctuations of all environmental variables present in the Benthocosms in so-called delta-treatments. Thereby we compared the physiological responses of F. vesiculosus (growth and metabolites to the single and combined effects of natural Kiel Fjord temperatures and pCO2 conditions with a 5 °C temperature increase and/or pCO2 increase treatment (1100 ppm in the headspace above the mesocosms. Responses were also related to the factor photoperiod which changes over the course of the year. Our results demonstrate complex seasonal pattern. Elevated pCO2 positively affected growth of F. vesiculosus alone and/or interactively with warming. The response direction (additive, synergistic or antagonistic, however, depended on season and daylength. The effects were most obvious when plants were actively growing during spring and early summer. Our study revealed for the first time that it is crucial to always consider the impact of variable environmental conditions throughout all seasons. In summary, our study indicates that in future F. vesiculosus will be more affected by detrimental summer heat-waves than by ocean acidification although the latter consequently enhances growth throughout the year. The mainly negative influence of rising

  17. Validation of inverse seasonal peak mortality in medieval plagues, including the Black Death, in comparison to modern Yersinia pestis-variant diseases.

    Directory of Open Access Journals (Sweden)

    Mark R Welford

    Full Text Available BACKGROUND: Recent studies have noted myriad qualitative and quantitative inconsistencies between the medieval Black Death (and subsequent "plagues" and modern empirical Y. pestis plague data, most of which is derived from the Indian and Chinese plague outbreaks of A.D. 1900+/-15 years. Previous works have noted apparent differences in seasonal mortality peaks during Black Death outbreaks versus peaks of bubonic and pneumonic plagues attributed to Y. pestis infection, but have not provided spatiotemporal statistical support. Our objective here was to validate individual observations of this seasonal discrepancy in peak mortality between historical epidemics and modern empirical data. METHODOLOGY/PRINCIPAL FINDINGS: We compiled and aggregated multiple daily, weekly and monthly datasets of both Y. pestis plague epidemics and suspected Black Death epidemics to compare seasonal differences in mortality peaks at a monthly resolution. Statistical and time series analyses of the epidemic data indicate that a seasonal inversion in peak mortality does exist between known Y. pestis plague and suspected Black Death epidemics. We provide possible explanations for this seasonal inversion. CONCLUSIONS/SIGNIFICANCE: These results add further evidence of inconsistency between historical plagues, including the Black Death, and our current understanding of Y. pestis-variant disease. We expect that the line of inquiry into the disputed cause of the greatest recorded epidemic will continue to intensify. Given the rapid pace of environmental change in the modern world, it is crucial that we understand past lethal outbreaks as fully as possible in order to prepare for future deadly pandemics.

  18. Validation of inverse seasonal peak mortality in medieval plagues, including the Black Death, in comparison to modern Yersinia pestis-variant diseases.

    Science.gov (United States)

    Welford, Mark R; Bossak, Brian H

    2009-12-22

    Recent studies have noted myriad qualitative and quantitative inconsistencies between the medieval Black Death (and subsequent "plagues") and modern empirical Y. pestis plague data, most of which is derived from the Indian and Chinese plague outbreaks of A.D. 1900+/-15 years. Previous works have noted apparent differences in seasonal mortality peaks during Black Death outbreaks versus peaks of bubonic and pneumonic plagues attributed to Y. pestis infection, but have not provided spatiotemporal statistical support. Our objective here was to validate individual observations of this seasonal discrepancy in peak mortality between historical epidemics and modern empirical data. We compiled and aggregated multiple daily, weekly and monthly datasets of both Y. pestis plague epidemics and suspected Black Death epidemics to compare seasonal differences in mortality peaks at a monthly resolution. Statistical and time series analyses of the epidemic data indicate that a seasonal inversion in peak mortality does exist between known Y. pestis plague and suspected Black Death epidemics. We provide possible explanations for this seasonal inversion. These results add further evidence of inconsistency between historical plagues, including the Black Death, and our current understanding of Y. pestis-variant disease. We expect that the line of inquiry into the disputed cause of the greatest recorded epidemic will continue to intensify. Given the rapid pace of environmental change in the modern world, it is crucial that we understand past lethal outbreaks as fully as possible in order to prepare for future deadly pandemics.

  19. Validation of Inverse Seasonal Peak Mortality in Medieval Plagues, Including the Black Death, in Comparison to Modern Yersinia pestis-Variant Diseases

    Science.gov (United States)

    Welford, Mark R.; Bossak, Brian H.

    2009-01-01

    Background Recent studies have noted myriad qualitative and quantitative inconsistencies between the medieval Black Death (and subsequent “plagues”) and modern empirical Y. pestis plague data, most of which is derived from the Indian and Chinese plague outbreaks of A.D. 1900±15 years. Previous works have noted apparent differences in seasonal mortality peaks during Black Death outbreaks versus peaks of bubonic and pneumonic plagues attributed to Y. pestis infection, but have not provided spatiotemporal statistical support. Our objective here was to validate individual observations of this seasonal discrepancy in peak mortality between historical epidemics and modern empirical data. Methodology/Principal Findings We compiled and aggregated multiple daily, weekly and monthly datasets of both Y. pestis plague epidemics and suspected Black Death epidemics to compare seasonal differences in mortality peaks at a monthly resolution. Statistical and time series analyses of the epidemic data indicate that a seasonal inversion in peak mortality does exist between known Y. pestis plague and suspected Black Death epidemics. We provide possible explanations for this seasonal inversion. Conclusions/Significance These results add further evidence of inconsistency between historical plagues, including the Black Death, and our current understanding of Y. pestis-variant disease. We expect that the line of inquiry into the disputed cause of the greatest recorded epidemic will continue to intensify. Given the rapid pace of environmental change in the modern world, it is crucial that we understand past lethal outbreaks as fully as possible in order to prepare for future deadly pandemics. PMID:20027294

  20. Trend and Seasonal Patterns of Injuries and Mortality Due to Motorcyclists Traffic Accidents; A Hospital-Based Study

    Directory of Open Access Journals (Sweden)

    Marjan Hosseinpour

    2017-01-01

    Full Text Available Objective: To investigate trend and seasonal pattern of occurrence and mortality of motorcycle accidents in patients referred to hospitals of Isfahan. Methods: This cross-sectional study was carried out using traffic accidents data of Isfahan province, extracted from Ministry of Health (MOH database from 2006 to 2010. During the study period, 83648 people injured due to motorcycle traffic accidents were referred to hospitals, all of them entered in the study. Logistic regression model was used to calculate the hospital mortality odds ratio, and Cochrane-Armitage test was used for assessment of linear trend. Results: During the study period, the hospital admission for motorcycle accident was 83,648 and 89.3% (74743 of them were men. Mean age in accidents time was 26.41±14.3 years. The injuries and death sex ratio were 8.4 and 16.9, respectively. Lowest admission rate was during autumn and highest during summer. The injury mortality odds ratio was 1.01 (CI 95% 0.73-1.39 in the Spring, 1.34 (CI95% 1.01-1.79 in summer and 1.17 (CI95% 0.83-1.63. It was also calculated to be 2.51 (CI95% 1.36-4.64 in age group 40-49, 2.39 (CI95% 1.51-5.68 in 50-59 and 4.79 (CI95% 2.49-9.22 in 60-69 years. The mortality odds ratio was 3.53 (CI95% 2.77-4.5 in rural place, 1.33 (CI95% 1.15-1.54 in men, and 2.44 (CI95% 2.09-2.85 in the road out of town and village. In addition, trend of motorcycle accidents mortality was increasing (p<0.001. Conclusion: Motorcycle accidents injuries are more common in men, summer, young age and rural roads. These high risk groups need more attention, care and higher training

  1. Effect of pre-cooling on repeat-sprint performance in seasonally acclimatised males during an outdoor simulated team-sport protocol in warm conditions.

    Science.gov (United States)

    Brade, Carly J; Dawson, Brian T; Wallman, Karen E

    2013-01-01

    Whether precooling is beneficial for exercise performance in warm climates when heat acclimatised is unclear. The purpose of this study was to determine the effect of precooling on repeat-sprint performance during a simulated team-sport circuit performed outdoors in warm, dry field conditions in seasonally acclimatised males (n = 10). They performed two trials, one with precooling (PC; ice slushy and cooling jacket) and another without (CONT). Trials began with a 30-min baseline/cooling period followed by an 80 min repeat-sprint protocol, comprising 4 x 20-min quarters, with 2 x 5-min quarter breaks and a 10-min half-time recovery/cooling period. A clear and substantial (negative; PC slower) effect was recorded for first quarter circuit time. Clear and trivial effects were recorded for overall circuit time, third and fourth quarter sprint times and fourth quarter best sprint time, otherwise unclear and trivial effects were recorded for remaining performance variables. Core temperature was moderately lower (Cohen's d=0.67; 90% CL=-1.27, 0.23) in PC at the end of the precooling period and quarter 1. No differences were found for mean skin temperature, heart rate, thermal sensation, or rating of perceived exertion, however, moderate Cohen's d effect sizes suggested a greater sweat loss in PC compared with CONT. In conclusion, repeat- sprint performance was neither clearly nor substantially improved in seasonally acclimatised players by using a combination of internal and external cooling methods prior to and during exercise performed in the field in warm, dry conditions. Of practical importance, precooling appears unnecessary for repeat-sprint performance if athletes are seasonally acclimatised or artificially acclimated to heat, as it provides no additional benefit. Key PointsPre-cooling did not improve repeated sprint performance during a prolonged team-sport circuit in field conditions.If individuals are already heat acclimatised/acclimated, pre-cooling is

  2. Evolution of an Intense Warm Frontal Precipitation Band During the GPM Cold-Season Precipitation Experiment (GCPEx)

    Science.gov (United States)

    Colle, Brian A.; Naeger, Aaron R.; Molthan, Andrew

    2017-01-01

    The band developed with low-level deformation and frontogenesis along the sloping warm frontal zone, and the vertical motions became large enough to produce graupel on the south side of the band. Embedded convective cells developed earlier in our GCPEx event, but the frontogenesis was weak then and banding was limited. As the deformation increased the stability also increased near the banding location (MPV* 0), which favored the development of single band. Through sensitivity studies (not shown) we found that latent heating helps increase the frontal circulations and resulting band development. Latent cooling also helps increase the frontogenesis given the evaporative and sublimation cooling within the frontal precipitation.

  3. Weather conditions and visits to the medical wing of emergency rooms in a metropolitan area during the warm season in Israel: a predictive model

    Science.gov (United States)

    Novikov, Ilya; Kalter-Leibovici, Ofra; Chetrit, Angela; Stav, Nir; Epstein, Yoram

    2012-01-01

    Global climate changes affect health and present new challenges to healthcare systems. The aim of the present study was to analyze the pattern of visits to the medical wing of emergency rooms (ERs) in public hospitals during warm seasons, and to develop a predictive model that will forecast the number of visits to ERs 2 days ahead. Data on daily visits to the ERs of the four largest medical centers in the Tel-Aviv metropolitan area during the warm months of the year (April-October, 2001-2004), the corresponding daily meteorological data, daily electrical power consumption (a surrogate marker for air-conditioning), air-pollution parameters, and calendar information were obtained and used in the analyses. The predictive model employed a time series analysis with transitional Poisson regression. The concise multivariable model was highly accurate ( r 2 = 0.819). The contribution of mean daily temperature was small but significant: an increase of 1°C in ambient temperature was associated with a 1.47% increase in the number of ER visits ( P electrical power consumption significantly attenuated the effect of weather conditions on ER visits by 4% per 1,000 MWh ( P forecasting the number of visits to ERs 2 days ahead. The marginal effect of temperature on the number of ER visits can be attributed to behavioral adaptations, including the use of air-conditioning.

  4. Mortality burden of the A/H1N1 pandemic in Mexico: a comparison of deaths and years of life lost to seasonal influenza.

    Science.gov (United States)

    Charu, Vivek; Chowell, Gerardo; Palacio Mejia, Lina Sofia; Echevarría-Zuno, Santiago; Borja-Aburto, Víctor H; Simonsen, Lone; Miller, Mark A; Viboud, Cécile

    2011-11-01

    The mortality burden of the 2009 A/H1N1 influenza pandemic remains controversial, in part because of delays in reporting of vital statistics that are traditionally used to measure influenza-related excess mortality. Here, we compare excess mortality rates and years of life lost (YLL) for pandemic and seasonal influenza in Mexico and evaluate laboratory-confirmed death reports. Monthly age- and cause-specific death rates from January 2000 through April 2010 and population-based surveillance of influenza virus activity were used to estimate excess mortality and YLL in Mexico. Age-stratified laboratory-confirmed A/H1N1 death reports were obtained from an active surveillance system covering 40% of the population. The A/H1N1 pandemic was associated with 11.1 excess all-cause deaths per 100,000 population and 445,000 YLL during the 3 waves of virus activity in Mexico, April-December 2009. The pandemic mortality burden was 0.6-2.6 times that of a typical influenza season and lower than that of the severe 2003-2004 influenza epidemic. Individuals aged 5-19 and 20-59 years were disproportionately affected relative to their experience with seasonal influenza. Laboratory-confirmed deaths captured 1 of 7 pandemic excess deaths overall but only 1 of 41 deaths in persons >60 years of age in 2009. A recrudescence of excess mortality was observed in older persons during winter 2010, in a period when influenza and respiratory syncytial virus cocirculated. Mexico experienced higher 2009 A/H1N1 pandemic mortality burden than other countries for which estimates are available. Further analyses of detailed vital statistics are required to assess geographical variation in the mortality patterns of this pandemic.

  5. Modelling the seasonality of Lyme disease risk and the potential impacts of a warming climate within the heterogeneous landscapes of Scotland.

    Science.gov (United States)

    Li, Sen; Gilbert, Lucy; Harrison, Paula A; Rounsevell, Mark D A

    2016-03-01

    Lyme disease is the most prevalent vector-borne disease in the temperate Northern Hemisphere. The abundance of infected nymphal ticks is commonly used as a Lyme disease risk indicator. Temperature can influence the dynamics of disease by shaping the activity and development of ticks and, hence, altering the contact pattern and pathogen transmission between ticks and their host animals. A mechanistic, agent-based model was developed to study the temperature-driven seasonality of Ixodes ricinus ticks and transmission of Borrelia burgdorferi sensu lato across mainland Scotland. Based on 12-year averaged temperature surfaces, our model predicted that Lyme disease risk currently peaks in autumn, approximately six weeks after the temperature peak. The risk was predicted to decrease with increasing altitude. Increases in temperature were predicted to prolong the duration of the tick questing season and expand the risk area to higher altitudinal and latitudinal regions. These predicted impacts on tick population ecology may be expected to lead to greater tick-host contacts under climate warming and, hence, greater risks of pathogen transmission. The model is useful in improving understanding of the spatial determinants and system mechanisms of Lyme disease pathogen transmission and its sensitivity to temperature changes.

  6. A multi-proxy warm season temperature reconstruction (3400 cal yr BP - 1500 cal yr BP) from the varved sediments of Lake Silvaplana

    Science.gov (United States)

    Stewart, Monique; Larocque, Isabelle; Grosjean, Martin

    2010-05-01

    A multi-proxy analysis of a nine-meter sediment core from Lake Silvaplana (1791 m a.s.l., 46°24'N, 9°42'E - 46°30'N, 9°52'E), including an innovative application of Spectrolino (380 - 730 nm) data, provides a decadal warm season temperature reconstruction (3400 cal yr BP - 1500 cal yr BP). The climate of this region has been shown to be representative of continental Europe (Trachsel et al., 2009). Consequently, we offer one of the first high-resolution multi-proxy records of European climate for this time period. The sediment of Silvaplana contains annual (‘varved') layers. Therefore, a chronology has been based on varve counts, 210Pb, 137Cs, documented flood layers and radiocarbon dates (Blass et al., 2007a;b). These varves enable high-resolution (sub-decadal) sampling and measurement of geochemical (Spectrolino, Biogenic Silica [BSi], varve thickness) and biological (chironomids) parameters. Spectrolino and BSi Flux measurements of the upper three meters of the core have been used to develop two independent calibrations-in-time and warm season (JJAS) temperature reconstructions back to AD 1177 (Spectrolino calibration period = 1864 - 1949; r = 0.92; pcorr = 0.001; BSi calibration period = 1864 - 1949; r = 0.67; pcorr = 0.03) (Trachsel et al., in review a;b; Blass et al., 2007b). A third warm season (July) temperature reconstruction to AD 1177 has been developed from chironomids (Larocque et al., 2009; Larocque-Tobler et al., 2009; accepted). Finally, Leemann and Niessen (1994), Ohlendorf et al. (1997), Nussbaumer et al. (in prep.) and Blass et al. (2007a) have shown a close relationship between local glacial activity and mean summer temperature. Here, the laboratory methods and calibrations-in-time previously used to reconstruct temperatures to AD 1177 are applied to the lower six meters of sediments (Spectrolino and varve thickness: 3400 cal yr BP - 1500 cal yr BP; BSi and chironomids: 2550 cal yr BP - 1810 cal yr BP). Both the BSi and chironomid based

  7. Disentangling Seasonality and Mean Annual Precipitation in the Indo-Pacific Warm Pool: Insights from Coupled Plant Wax C and H Isotope Measurements

    Science.gov (United States)

    Galy, V.; Oppo, D.; Dubois, N.; Arbuszewski, J. A.; Mohtadi, M.; Schefuss, E.; Rosenthal, Y.; Linsley, B. K.

    2016-12-01

    There is ample evidence suggesting that rainfall distribution across the Indo-Pacific Warm Pool (IPWP) - a key component of the global climate system - has substantially varied over the last deglaciation. Yet, the precise nature of these hydroclimate changes remains to be elucidated. In particular, the relative importance of variations in precipitation seasonality versus annual precipitation amount is essentially unknown. Here we use a set of surface sediments from the IPWP covering a wide range of modern hydroclimate conditions to evaluate how plant wax stable isotope composition records rainfall distribution in the area. We focus on long chain fatty acids, which are exclusively produced by vascular plants living on nearby land and delivered to the ocean by rivers. We relate the C (δ13C) and H (δD) isotope composition of long chain fatty acids preserved in surface sediments to modern precipitation distribution and stable isotope composition in their respective source area. We show that: 1) δ13C values reflect vegetation distribution (in particular the relative abundance of C3 and C4 plants) and are primarily recording precipitation seasonality (Dubois et al., 2014) and, 2) once corrected for plant fractionation effects, δD values reflect the amount-weighted average stable isotope composition of precipitation and are primarily recording annual precipitation amounts. We propose that combining the C and H isotope composition of long chain fatty acids thus allows independent reconstructions of precipitation seasonality and annual amounts in the IPWP. The practical implications for reconstructing past hydroclimate in the IPWP will be discussed.

  8. The Impact of Storm Tracks on Warm-Season Precipitation in the Midwest: Contrasting the 1988 Drought and 1993 Flood

    Directory of Open Access Journals (Sweden)

    Timothy Paul Eichler

    2016-01-01

    Full Text Available To assess the role of cyclone tracks in contributing to floods and droughts, we highlight the role of midlatitude cyclones played in the 1988 drought and the 1993 flood. Our results demonstrate that the 1988 drought featured a poleward-displaced cyclone track with a reduced role for cyclone-induced precipitation, especially in the spring of 1988. The 1993 flood featured a cyclone track from Mexico northeast to Missouri in the spring, while the summer featured two cyclone tracks: one in the southwestern US and the other across Canada linked to the right-entrance and left-exit regions of a strong 200 hPa Jetstream across the upper Midwest. Enhanced 850 hPa inflow from the Caribbean northeast to the Midwest with high precipitable water values occurred in conjunction with the right entrance portion of the 200 hPa Jetstream. Linking storm tracks and the 200 hPa Jetstream to a storm-rain index for the Midwest showed that these extreme events conformed to features of the general circulation normally associated with wet/dry episodes in the warm half of the year. Although El Niño did not play a role in the 1993 flood, the 1988 drought was associated with a poleward displacement of cyclone tracks in response to La Niña.

  9. Climate warming due to increasing atmospheric CO2 - Simulations with a multilayer coupled atmosphere-ocean seasonal energy balance model

    Science.gov (United States)

    Li, Peng; Chou, Ming-Dah; Arking, Albert

    1987-01-01

    The transient response of the climate to increasing CO2 is studied using a modified version of the multilayer energy balance model of Peng et al. (1982). The main characteristics of the model are described. Latitudinal and seasonal distributions of planetary albedo, latitude-time distributions of zonal mean temperatures, and latitudinal distributions of evaporation, water vapor transport, and snow cover generated from the model and derived from actual observations are analyzed and compared. It is observed that in response to an atmospheric doubling of CO2, the model reaches within 1/e of the equilibrium response of global mean surface temperature in 9-35 years for the probable range of vertical heat diffusivity in the ocean. For CO2 increases projected by the National Research Council (1983), the model's transient response in annually and globally averaged surface temperatures is 60-75 percent of the corresponding equilibrium response, and the disequilibrium increases with increasing heat diffusivity of the ocean.

  10. Seasonal variation in the acute effect of particulate air pollution on mortality in the China Air Pollution and Health Effects Study (CAPES)

    Science.gov (United States)

    Chen, Renjie; Peng, Roger D.; Meng, Xia; Zhou, Zhijun; Chen, Bingheng; Kan, Haidong

    2013-01-01

    Epidemiological findings concerning the seasonal variation in the acute effect of particulate matter (PM) are inconsistent. We investigated the seasonality in the association between PM with an aerodynamic diameter of less than 10 μm (PM10) and daily mortality in 17 Chinese cities. We fitted the “main” time-series model after adjustment for time-varying confounders using smooth functions with natural splines. We established a “seasonal” model to obtain the season-specific effect estimates of PM10, and a “harmonic” model to show the seasonal pattern that allows PM10 effects to vary smoothly with the day in a year. At the national level, a 10 μg/m3 increase in the two-day moving average concentrations (lag 01) of PM10 was associated with 0.45% [95% posterior interval (PI), 0.15% to 0.76%], 0.17% (95% PI, −0.09% to 0.43%), 0.55% (95% PI, 0.15% to 0.96%) and 0.25% (95%PI, −0.05% to 0.56%) increases in total mortality for winter, spring, summer and fall, respectively. For the smoothly-varying plots of seasonality, we identified a two-peak pattern in winter and summer. The observed seasonal pattern was generally insensitive to model specifications. Our analyses suggest that the acute effect of particulate air pollution could vary by seasons with the largest effect in winter and summer in China. To our knowledge, this is the first multicity study in developing countries to analyze the seasonal variations of PM-related health effects. PMID:23500824

  11. Seasonal variation in nativity and mortality and in socioeconomic conditions in a single family residing at different latitudes: Germany versus South Africa

    Directory of Open Access Journals (Sweden)

    Lemmer B

    2014-08-01

    Full Text Available Björn Lemmer Institute of Experimental and Clinical Pharmacology and Toxicology, Ruprecht-Karls-University of Heidelberg, Mannheim, Germany Abstract: This is the first report in which seasonal patterns in nativity and mortality were analyzed in a single family, branches of which have resided in the middle of Europe as well as in South Africa for several hundreds of years. The family included a total of 3,645 members. The data convincingly demonstrate the effect of the seasonal amplitude of the photoperiod, as represented by the different latitudes, on the seasonal rhythm in nativity and mortality, discernible from 1500–1950 in Europe at 51° N but not in South Africa at 30° S. Most interestingly, this pattern in Germany was lost in the second half of the 20th century, possibly because of socioeconomic conditions and masking effects from the introduction of new technology to better control environmental conditions, greater use of artificial light, further incorporation of shiftwork schedules in industry, stronger advances in medical treatment of many diseases (including increased availability of intensive care in hospitals, and finally, greater longevity of the population. Keywords: season, latitude, Germany, South Africa, nativity, mortality, weddings, birth of first child

  12. The Role of Vegetation in Mitigating Urban Land Surface Temperatures: A Case Study of Munich, Germany during the Warm Season

    Directory of Open Access Journals (Sweden)

    Sadroddin Alavipanah

    2015-04-01

    Full Text Available The Urban Heat Island (UHI is the phenomenon of altered increased temperatures in urban areas compared to their rural surroundings. UHIs grow and intensify under extreme hot periods, such as during heat waves, which can affect human health and also increase the demand for energy for cooling. This study applies remote sensing and land use/land cover (LULC data to assess the cooling effect of varying urban vegetation cover, especially during extreme warm periods, in the city of Munich, Germany. To compute the relationship between Land Surface Temperature (LST and Land Use Land Cover (LULC, MODIS eight-day interval LST data for the months of June, July and August from 2002 to 2012 and the Corine Land Cover (CLC database were used. Due to similarities in the behavior of surface temperature of different CLCs, some classes were reclassified and combined to form two major, rather simplified, homogenized classes: one of built-up area and one of urban vegetation. The homogenized map was merged with the MODIS eight-day interval LST data to compute the relationship between them. The results revealed that (i the cooling effect accrued from urban vegetation tended to be non-linear; and (ii a remarkable and stronger cooling effect in terms of LST was identified in regions where the proportion of vegetation cover was between seventy and almost eighty percent per square kilometer. The results also demonstrated that LST within urban vegetation was affected by the temperature of the surrounding built-up and that during the well-known European 2003 heat wave, suburb areas were cooler from the core of the urbanized region. This study concluded that the optimum green space for obtaining the lowest temperature is a non-linear trend. This could support urban planning strategies to facilitate appropriate applications to mitigate heat-stress in urban area.

  13. Improving a tree-ring reconstruction from west-central Scandinavia: 900 years of warm-season temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Gunnarson, Bjoern E. [Swedish University of Agricultural Sciences, Department of Forest Ecology and Management, Umeaa (Sweden); Stockholm University, Department of Physical Geography and Quaternary Geology, Stockholm (Sweden); Linderholm, Hans W. [University of Gothenburg, Regional Climate Group, Department of Earth Sciences, Gothenburg (Sweden); Moberg, Anders [Stockholm University, Department of Physical Geography and Quaternary Geology, Stockholm (Sweden)

    2011-01-15

    Dendroclimatological sampling of Scots pine (Pinus sylvestris L.) has been made in the province of Jaemtland, in the west-central Scandinavian mountains, since the 1970s. The tree-ring width (TRW) chronology spans several thousand years and has been used to reconstruct June-August temperatures back to 1632 bc. A maximum latewood density (MXD) dataset, covering the period ad 1107-1827 (with gap 1292-1315) was presented in the 1980s by Fritz Schweingruber. Here we combine these historical MXD data with recently collected MXD data covering ad 1292-2006 into a single reconstruction of April-September temperatures for the period ad 1107-2006. Regional curve standardization (RCS) provides more low-frequency variability than ''non-RCS'' and stronger correlation with local seasonal temperatures (51% variance explained). The MXD chronology shows a stronger relationship with temperatures than the TRW data, but the two chronologies show similar multi-decadal variations back to ad 1500. According to the MXD chronology, the period since ad 1930 and around ad 1150-1200 were the warmest during the last 900 years. Due to large uncertainties in the early part of the combined MXD chronology, it is not possible to conclude which period was the warmest. More sampling of trees growing near the tree-line is needed to further improve the MXD chronology. (orig.)

  14. The Effect of Aerosol-Cloud-Vegetation Interactions and Intraseasonal Meteorological Variability on Warm Cloud Development during the Amazonian Biomass Burning Season

    Science.gov (United States)

    Ten Hoeve, J. E.; Remer, L. A.; Jacobson, M. Z.

    2009-12-01

    The effect of aerosols on the hydrological cycle remains one of the largest uncertainties in our climate system. Biomass burning, from both deforestation and annual agricultural burning, is the largest anthropogenic source of these aerosols in the Southern Hemisphere. Biomass burning aerosols have competing effects on clouds: Depending on the level of aerosol loading and the background cloud characteristics, biomass burning aerosols have been shown in observational studies to invigorate or inhibit cloud formation and/or growth through microphysical and absorptive pathways, respectively. Many of these previous studies have employed all days during the Amazonian burning season months of August through October to formulate aerosol-cloud correlations, assuming relatively constant meteorological conditions exist throughout these months. This study investigates how intraseasonal trends of precipitable water vapor and aerosol loading between August and October impact these aerosol-cloud correlations. Other factors affecting aerosol-cloud relationships, such as atmospheric stability, are also investigated. This study is focused on a small 3 degree NE x 4 degree WE region in Rondonia, Brazil that encompasses extensive, contiguous areas of both forested and deforested land. High resolution aerosol, cloud, water vapor, and atmospheric profile data from the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra and Aqua satellites, as well as aerosol and water vapor data from the Aerosol Robotic Network (AERONET), are used collectively to explore the effect of aerosols on water vapor loading and warm cloud development over the Amazon. The difference in aerosol effects on the local hydrological cycle over forested and deforested areas is also examined. This final exercise provides insight into the relationship between aerosols, land-atmosphere processes, and warm clouds.

  15. Effect of Doubling the Ensemble Size on the Performance of Ensemble Prediction in the Warm Season Using MOGREPS Implemented at the KMA

    Institute of Scientific and Technical Information of China (English)

    Jun Kyung KAY; Hyun Mee KIM; Young-Youn PARK; Joohyung SON

    2013-01-01

    Using the Met Office Global and Regional Ensemble Prediction System (MOGREPS) implemented at the Korea Meteorological Administration (KMA),the effect of doubling the ensemble size on the performance of ensemble prediction in the warm season was evaluated.Because a finite ensemble size causes sampling error in the full forecast probability distribution function (PDF),ensemble size is closely related to the efficiency of the ensemble prediction system.Prediction capability according to doubling the ensemble size was evaluated by increasing the number of ensembles from 24 to 48 in MOGREPS implemented at the KMA.The initial analysis perturbations generated by the Ensemble Transform Kalman Filter (ETKF) were integrated for 10 days from 22 May to 23 June 2009.Several statistical verification scores were used to measure the accuracy,reliability,and resolution of ensemble probabilistic forecasts for 24 and 48 ensemble member forecasts.Even though the results were not significant,the accuracy of ensemble prediction improved slightly as ensemble size increased,especially for longer forecast times in the Northern Hemisphere.While increasing the number of ensemble members resulted in a slight improvement in resolution as forecast time increased,inconsistent results were obtained for the scores assessing the reliability of ensemble prediction.The overall performance of ensemble prediction in terms of accuracy,resolution,and reliability increased slightly with ensemble size,especially for longer forecast times.

  16. The use of constructed wetlands for the treatment and reuse of urban wastewater for the irrigation of two warm-season turfgrass species under Mediterranean climatic conditions.

    Science.gov (United States)

    Licata, Mario; Tuttolomondo, Teresa; Leto, Claudio; La Bella, Salvatore; Virga, Giuseppe

    2017-07-01

    Constructed wetlands (CWs) represent low-cost technology for the treatment and reuse of wastewater in urban areas. This study aimed to evaluate the pollutant removal efficiency of a CW system and to assess the effects of irrigation using treated urban wastewater on soil and on two warm-season turf species. The research was carried out in Sicily (Italy) on a pilot-scale horizontal subsurface flow system which was fed with treated urban wastewater following secondary treatment from an activated-sludge wastewater treatment plant. The pilot system was located in an open urban park and comprised two separate parallel planted units. Experimental fields of Cynodon dactylon (L.) Pers. and Paspalum vaginatum Sw. were set up close to the system and irrigated with both treated wastewater (TWW) and freshwater (FW). Irrigation with TWW did not result in a significant variation in soil pH and soil salinity in the topsoil. The turf species tolerated high sodium levels in the soil due to TWW irrigation. Savings in FW and mineral fertilizers were deemed significant. The results highlight the fact that use of CW systems for the treatment and reuse of wastewater can represent a sustainable way to obtain alternative water resources for turfgrass irrigation in urban areas.

  17. Coupled prediction of flood response and debris flow initiation during warm- and cold-season events in the Southern Appalachians, USA

    Science.gov (United States)

    Tao, J.; Barros, A. P.

    2014-01-01

    Debris flows associated with rainstorms are a frequent and devastating hazard in the Southern Appalachians in the United States. Whereas warm-season events are clearly associated with heavy rainfall intensity, the same cannot be said for the cold-season events. Instead, there is a relationship between large (cumulative) rainfall events independently of season, and thus hydrometeorological regime, and debris flows. This suggests that the dynamics of subsurface hydrologic processes play an important role as a trigger mechanism, specifically through soil moisture redistribution by interflow. We further hypothesize that the transient mass fluxes associated with the temporal-spatial dynamics of interflow govern the timing of shallow landslide initiation, and subsequent debris flow mobilization. The first objective of this study is to investigate this relationship. The second objective is to assess the physical basis for a regional coupled flood prediction and debris flow warning system. For this purpose, uncalibrated model simulations of well-documented debris flows in headwater catchments of the Southern Appalachians using a 3-D surface-groundwater hydrologic model coupled with slope stability models are examined in detail. Specifically, we focus on two vulnerable headwater catchments that experience frequent debris flows, the Big Creek and the Jonathan Creek in the Upper Pigeon River Basin, North Carolina, and three distinct weather systems: an extremely heavy summertime convective storm in 2011; a persistent winter storm lasting several days; and a severe winter storm in 2009. These events were selected due to the optimal availability of rainfall observations; availability of detailed field surveys of the landslides shortly after they occurred, which can be used to evaluate model predictions; and because they are representative of events that cause major economic losses in the region. The model results substantiate that interflow is a useful prognostic of conditions

  18. Efeito sazonal sobre a natimortalidade e mortalidade de leitões até 21 dias de idade Season effect on natal mortality and mortality in piglets up to 21 day of age

    Directory of Open Access Journals (Sweden)

    Francisco Antonio Tenorio Fireman

    1997-08-01

    Full Text Available Foram analisadas fichas de notificação de nascimento de 3032 leitões da raça Large White, nascidos no período de 1984 a 1987, cedidas pela Associação Brasileira dos Criadores de Suínos. Os dados utilizados são provenientes de uma granja comercial de suínos, sediada no estado do Rio Grande do Sul. Neste estudo, foram determinadas a natimortalidade e a mortalidade de leitões até 21 dias de idade, em diferentes condições sazonais nos quatro anos analisados. O efeito da sazonalidade sobre a natimortalidade e mortalidade até 21 dias de idade foi significativo. A maior ocorrência de natimortalidade foi no outono (0,47 leitões/leitegada e na primavera (0,50 leitões/leitegada. A maior incidência de mortalidade do nascimento até 21 dias de idade foi observada no inverno (1,96 leitões/leitegada e no verão (1,79 leitões mortos/leitegada.Birth records of 3032 piglets of the Large White breed, born during the period between 1984 and 1987 were sent for analyses by the Associação Brasileira de Criadores de Suínos. The data used came from a commercial farm in the state of Rio Grande do Sul, Brazil. Natal mortality and mortality of piglets up to 21 days of age were determined in different season condition during three years of analysis. The effect of season on there parameters was significative. The larger number of stillbirths was observed in the spring (0.50 piglets and fall (0.47 piglets seasons. The higher percentage of preweaning mortality was observed in the winter (1.96 piglets/offsping and in the summer (1.79 piglets/offspring seasons.

  19. Mean surface fields of heat budget components over the warm pool in the Bay of Bengal during post-monsoon season

    Digital Repository Service at National Institute of Oceanography (India)

    Sadhuram, Y.; Rao, D.P.; Rao, B.P.

    as warm pool) except in North Bay of Bengal where it was less than 28 degrees C. SST was very high (greater than 30 degrees C) off Sri Lanka. Net total insolation (Q sub(1)) varied between 200 and 240 Wm sup(-2) over the warm pool, effective back radiation...

  20. Greenhouse gas flux under warm-season perennial C4 grasses across different soil and climate gradients on the Islands of Hawaii

    Science.gov (United States)

    Pawlowski, M. N.; Crow, S. E.; Sumiyoshi, Y.; Wells, J.; Kikkawa, H. R.

    2011-12-01

    Agricultural soils can serve as either a sink or a source for atmospheric carbon (C) and other greenhouse gases (GHG). This is particularly true for tropical soils where influences from climate and soil gradients are wide ranging. Current estimates of GHG flux from soil are often under or overestimated due to high variability in sample sites and inconsistencies in land use and vegetation type, making extrapolation to new study systems difficult. This work aimed to identify patterns of trace fluxes of carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) across two soil types and three species of warm season perennial C4 grasses: Pennisetum purpureum (Napier grass), Panicum maximum (Guinea grass) and Saccharum officinarum (sugar cane) on the islands of Oahu and Maui in Hawaii. Multiple static vented chambers were installed into replicate plots for each species; flux measurements were made during the growth, fertilization and harvest cycles at set time intervals for one hour and analyzed by gas chromatography. Initial results from Oahu indicate no significant differences in CO2 flux between the P. maximum and P. purpureum species after fertilization or at full growth. We observed an average flux of 143 mg m-2 h-1 and 155 mg m-2 h-1 for P. maximum and P. purpureum respectively at full growth for CO2 and 1.7 μg m-2 h-1and 0.3 μg m-2 h-1 for N2O. Additionally, N2O rates sampled after a typical fertilizer application were significantly greater than at full growth (p=0.0005) with flux rates of 25.2 μg m2h-1 and 30.3 μg m2h-1 for P. maximum and P. purpureum respectively. With a global warming potential of 310 for N2O, even short-term spikes following fertilizer application can cause long lasting effects of GHG emission from agricultural soils. CH4 flux was negligible for all species on the Oahu plots during these sample periods. Globally, water limitation is a major factor influencing the potential productivity of agricultural crops and the sustainability of

  1. Growth and mortality of larval and juvenile Japanese seaperch Lateolabrax japonicus in relation to seasonal changes in temperature and prey abundance in the Chikugo estuary

    Science.gov (United States)

    Shoji, Jun; Tanaka, Masaru

    2007-07-01

    Japanese seaperch Lateolabrax japonicus migrate from Ariake Bay to the estuarine turbidity maximum (ETM) zone of the Chikugo River and inhabit there through the post-migration period (15-20 mm in standard length). The feeding, growth and mortality during the post-migration period of Japanese seaperch were analyzed in relation to seasonal changes in temperature and prey concentration. Larvae and juveniles were collected from ten sampling stations at 4-7 day intervals from 24 February to 24 April 2005 in the Chikugo estuary. Based on the otolith microstructure analysis the sampled fish were divided into nine cohorts, each cohort covering a 5 day hatch date period (22 December 2004 to 4 February 2005). The growth coefficient ( G, day -1) was higher and the mortality coefficient ( M, day -1) was lower in the later cohorts. The ratio of G to M as an index of stage-specific survival during the post-migration period significantly increased as the season progressed and exceeded 1.0 in the last cohort examined. Variability in abundance of the major prey organism, Sinocalanus sinensis, had a significant effect on the Japanese seaperch ingestion rate. Increase in temperature and spring bloom of S. sinensis is concluded to provide the later cohorts with a higher survival probability through increasing ingestion and growth rates during their post-migration period in spring 2005.

  2. Nonintrusive field experiments show different plant responses to warming and drought among sites, seasons, and species in a north-south European gradient

    DEFF Research Database (Denmark)

    Penuelas, J.; Gordon, C.; Llorens, L.;

    2004-01-01

    of experimentation reported here, we measured plant cover and biomass by the pinpoint method, plant (14)C uptake, stem and shoot growth, flowering, leaf chemical concentration, litterfall, and herbivory damage in the dominant plant species of each site. The two years of approximately PC experimental warming induced......-limited. In the water-stressed southern site, there was no increase in total aboveground plant biomass growth as expected since warming increases water loss, and temperatures in those ecosystems are already close to the optimum for photosynthesis. The southern site presented instead the most negative response......We used a novel, nonintrusive experimental system to examine plant responses to warming and drought across a climatic and geographical latitudinal gradient of shrubland ecosystems in four sites from northern to southern Europe (UK, Denmark, The Netherlands, and Spain). In the first two years...

  3. Bacterial carbon cycling in an sub-arctic fjord: A seasonal study on microbial activity, growth efficiency and virus induced mortality in Kobbefjord, Greenland

    DEFF Research Database (Denmark)

    Middelboe, Mathias; Glud, Ronnie N.; Sejr, Michael K.

    2012-01-01

    of viruses on bacterial mortality (4–36% of cell production) and carbon cycling. Heterotrophic bacterial consumption was closely coupled with autochthonous BDOC production, and the majority of the primary production was consumed by pelagic bacteria at all seasons. The relatively low measured BGE emphasized......In this seasonal study, we examined the environmental controls and quantitative importance of bacterial carbon consumption in the water column and the sediment in the subarctic Kobbefjord, Greenland. Depth-integrated bacterial production in the photic zone varied from 5.0 ± 2.7 mg C m−2 d−1...... in February to 42 ± 28 mg C m−2 d−1 in May and 34 ± 7 mg C m−2 d−1 in September, corresponding to a bacterial production to primary production ratio of 0.34 ± 0.14, 0.07 ± 0.04, and 0.08 ± 0.06, respectively. Based on measured bacterial growth efficiencies (BGEs) of 0.09–0.10, pelagic bacterial carbon...

  4. Nonintrusive Field Experiments Show Different Plant Responses to Warming and Drought Among Sites, Seasons, and Species in a North-South European Gradient

    NARCIS (Netherlands)

    Peñuelas, J.; Gordon, C.; Llorens, L.; Nielsen, T.; Tietema, A.; Beier, J.C.; Bruna, P.; Emmett, B.; Estiarte, M.; Gorissen, A.

    2004-01-01

    We used a novel, nonintrusive experimental system to examine plant responses to warming and drought across a climatic and geographical latitudinal gradient of shrubland ecosystems in four sites from northern to southern Europe (UK, Denmark, The Netherlands, and Spain). In the first two years of expe

  5. Nonintrusive Field Experiments Show Different Plant Responses to Warming and Drought Among Sites, Seasons, and Species in a North-South European Gradient

    NARCIS (Netherlands)

    Peñuelas, J.; Gordon, C.; Llorens, L.; Nielsen, T.; Tietema, A.; Beier, J.C.; Bruna, P.; Emmett, B.; Estiarte, M.; Gorissen, A.

    2004-01-01

    We used a novel, nonintrusive experimental system to examine plant responses to warming and drought across a climatic and geographical latitudinal gradient of shrubland ecosystems in four sites from northern to southern Europe (UK, Denmark, The Netherlands, and Spain). In the first two years of

  6. 长江流域地区延长暖季型草坪草绿期技术研究%Technology Research of Prolonging the Warm Season Turf in the Yangtze River Basin

    Institute of Scientific and Technical Information of China (English)

    江生泉; 姜自红; 薛正帅

    2015-01-01

    草坪是环境生态系统的重要组成部分,是园林绿化的主要方式之一,在长江流域暖季型草坪草冬季休眠枯黄,影响其草坪景观,延长草坪绿期和实现周年常绿是当前研究重点。分析了气候、养护管理对暖季型草坪草绿期影响,阐述了延长绿期方法和实现周年常绿的技术措施。%Lawn is an important part of the environmental ecosystem ,and is one of the main ways of landscape gardening .Winter dormancy of warm season turf affects the lawn landscape in the Yangtze River Basin ,and prolonging green period has become the focus of the current research .The paper analyzes the effects of climate and the maintenance management on green period of warm season turf and expounds the technical measures to prolong the green period and realize the annual evergreen .

  7. Changes in Patterns of Seasonality Shown by Migratory Fish under Global Warming: Evidence from Catch Data of Taiwan’s Coastal Fisheries

    Directory of Open Access Journals (Sweden)

    Ching-Hsien Ho

    2016-03-01

    Full Text Available In this study, we analyzed the fish species composition data of coastal capture fisheries in Taiwan between 1963 and 2010. The purpose of the analysis was to understand the long-term changes in marine ecosystems. A ratio-to-moving average method was used in conjunction with adjusted seasonal indices to determine the seasonality of individual catch items and to examine the trends shown by the species with the same seasonality. Over the 48-year timespan of the data, 31 species, i.e., 64% of the total number of species, were identified as seasonal migrants. The catch ratio for species showing a single peak in the spring increased steadily over time; however, those species with a single peak in the winter decreased. The catch ratio for those species with dual peaks in both summer and fall varied greatly before 1978. Increasing trends began in the 1980s and accelerated until 1998. As a result of this increase, the previous concentration of the fishing season in the winter months became highly diffuse. Additionally, the winter and/or spring species continued to decrease year after year as the summer and/or autumn species gradually came to dominate the catch. This change in fishing seasonality is likely not an anthropogenic effect. However, the change coincides with trends in sea surface temperature fluctuations. Such variation may not only cause structural change in marine ecosystems but can also significantly impact the economy and the livelihoods of those associated with the fishing trade.

  8. Climatic warming above the Arctic Circle: are there trends in timing and length of the thermal growing season in Murmansk Region (Russia) between 1951 and 2012?

    Science.gov (United States)

    Blinova, Ilona; Chmielewski, Frank-Michael

    2015-06-01

    Anomalies in the timing of the thermal growing season have become obvious in the NE part of Fennoscandia since 2000. They are in accordance with climatic changes reported for Europe and Fennoscandia. The actual length of the growing season reached 120 days on average, onset on 30 May and ending on 27 September (1981-2010). Shifts in the timing of the growing season and its mean prolongation by 18.5 days/62a are demonstrated for Murmansk Region (1951-2012). In this period, the onset of the growing season advanced by 7.1 days/62a, while the end was extended by 11.4 days/62a. The delay in the end of the growing season is similar to the entire Fennoscandian pattern but it has not been detected in the rest of Europe. The regional pattern of climatic regimes in Murmansk Region remained stable in comparison with earlier climatic maps (1971). However, the actual shifts in the timing of the growing season were more pronounced in colder (oceanic and mountainous) parts. Recent climatic trends could influence the retreat of the tundra zone and changes in the forest line. Losses of tundra biodiversity and enrichment of the northern taiga by southern species could be expected from present climatic trends.

  9. Patterns of bleaching and mortality following widespread warming events in 2014 and 2015 at the Hanauma Bay Nature Preserve, Hawai‘i

    Directory of Open Access Journals (Sweden)

    Ku‘ulei S. Rodgers

    2017-05-01

    Full Text Available Drastic increases in global carbon emissions in the past century have led to elevated sea surface temperatures that negatively affect coral reef organisms. Worldwide coral bleaching-related mortality is increasing and data has shown even isolated and protected reefs are vulnerable to the effects of global climate change. In 2014 and 2015, coral reefs in the main Hawaiian Islands (MHI suffered up to 90% bleaching, with higher than 50% subsequent mortality in some areas. The location and severity of bleaching and mortality was strongly influenced by the spatial and temporal patterns of elevated seawater temperatures. The main objective of this research was to understand the spatial extent of bleaching mortality in Hanauma Bay Nature Preserve (HBNP, O‘ahu, Hawai‘i to gain a baseline understanding of the physical processes that influence localized bleaching dynamics. Surveys at HBNP in October 2015 and January 2016 revealed extensive bleaching (47% and high levels of coral mortality (9.8%. Bleaching was highly variable among the four HBNP sectors and ranged from a low of ∼31% in the central bay at Channel (CH to a high of 57% in the area most frequented by visitors (Keyhole; KH. The highest levels of bleaching occurred in two sectors with different circulation patterns: KH experienced comparatively low circulation velocity and a low temperature increase while Witches Brew (WB and Backdoors (BD experienced higher circulation velocity and higher temperature increase. Cumulative mortality was highest at WB (5.0% and at BD (2.9% although WB circulation velocity is significantly higher. HBNP is minimally impacted by local factors that can lead to decline such as high fishing pressure or sedimentation although human use is high. Despite the lack of these influences, high coral mortality occurred. Visitor impacts are strikingly different in the two sectors that experienced the highest mortality evidenced by the differences in coral cover associated

  10. Investigation of the differences between deepening and intensification for 500-hpa cyclones in central and East Mediterranean region during warm season of the year

    Directory of Open Access Journals (Sweden)

    S. Spanos

    2006-01-01

    Full Text Available The maximum deepening rate per cyclone track is determined by the maximum height drop at the center of the cyclone (500-hPa low on the basis of all the 6-h successive steps in its life cycle. The geopotential height gradient is calculated over the entire low area and the calculation continued with the variation of the gradient in the successive steps. The maximum intensification rate per cyclone is then determined as the maximum increase of the gradient in the life cycle. Maximum deepening rate for the 500-hPa cyclones in the area does not exceed, on average, 12 gpm/6 h. Maximum intensification which is 1.4 gpm/100 Km*6 h on average, occurs in the early stages of the cyclone's life cycle. This on the average happens approximately 9 h after the first time the low is detected. At the gulf of Genoa and the Adriatic Sea, cyclones usually show the maximum intensification after the maximum deepening. At Turkey's cyclogenesis area, however, this order is reversed. The spatial distributions of maximum intensification in the three sub-periods, indicate that it mainly occurs over Seas during late warm periods and over land during early and middle warm periods. Such a behavior underlines the role of low-level instability in cyclone development.

  11. Polar Warming Drivers

    Science.gov (United States)

    McDunn, T. L.; Bougher, S. W.; Mischna, M. A.; Murphy, J. R.

    2012-12-01

    Polar warming is a dynamically induced temperature enhancement over mid-to-high latitudes that results in a reversed (poleward) meridional temperature gradient. This phenomenon was recently characterized over the 40-90 km altitude region [1] based on nearly three martian years of Mars Climate Sounder observations [2, 3]. Here we investigate which forcing mechanisms affect the magnitude and distribution of the observed polar warming by conducting simulations with the Mars Weather Research and Forecasting General Circulation Model [4, 5]. We present simulations confirming the influence topography [6] and dust loading [e.g., 7] have upon polar warming. We then present simulations illustrating the modulating influence gravity wave momentum deposition exerts upon polar warming, consistent with previous modeling studies [e.g., 8]. The results of this investigation suggest the magnitude and distribution of polar warming in the martian middle atmosphere is modified by gravity wave activity and that the characteristics of the gravity waves that most significantly affect polar warming vary with season. References: [1] McDunn, et al., 2012 (JGR), [2]Kleinböhl, et al., 2009 (JGR), [3] Kleinböhl, et al., 2011 (JQSRT), [4] Richardson, et al., 2007 (JGR), [5] Mischna, et al., 2011 (Planet. Space Sci.), [6] Richardson and Wilson, 2002 (Nature), [7] Haberle, et al., 1982 (Icarus), [8] Barnes, 1990 (JGR).

  12. Lagged effect of diurnal temperature range on mortality in a subtropical megacity of China.

    Directory of Open Access Journals (Sweden)

    Yuan Luo

    Full Text Available BACKGROUND: Many studies have found extreme temperature can increase the risk of mortality. However, it is not clear whether extreme diurnal temperature range (DTR is associated with daily disease-specific mortality, and how season might modify any association. OBJECTIVES: To better understand the acute effect of DTR on mortality and identify whether season is a modifier of the DTR effect. METHODS: The distributed lag nonlinear model (DLNM was applied to assess the non-linear and delayed effects of DTR on deaths (non-accidental mortality (NAD, cardiovascular disease (CVD, respiratory disease (RD and cerebrovascular disease (CBD in the full year, the cold season and the warm season. RESULTS: A non-linear relationship was consistently found between extreme DTR and mortality. Immediate effects of extreme low DTR on all types of mortality were stronger than those of extreme high DTR in the full year. The cumulative effects of extreme DTRs increased with the increment of lag days for all types of mortality in cold season, and they were greater for extreme high DTRs than those of extreme low DTRs. In hot season, the cumulative effects for extreme low DTRs increased with the increment of lag days, but for extreme high DTR they reached maxima at a lag of 13 days for all types of mortality except for CBD(at lag6 days, and then decreased. CONCLUSIONS: Our findings suggest that extreme DTR is an independent risk factor of daily mortality, and season is a modifier of the association of DTR with daily mortality.

  13. Understanding the Impact of Ground Water Treatment and Evapotranspiration Parameterizations in the NCEP Climate Forecast System (CFS) on Warm Season Predictions

    Science.gov (United States)

    Ek, M. B.; Yang, R.

    2016-12-01

    Skillful short-term weather forecasts, which rely heavily on quality atmospheric initial conditions, have a fundamental limit of about two weeks owing to the chaotic nature of the atmosphere. Useful forecasts at sub-seasonal to seasonal time scales, on the other hand, require well-simulated large-scale atmospheric response to slowly varying lower boundary forcings from both the ocean and land surface. The critical importance of ocean has been recognized, where the ocean indices have been used in a variety of climate applications. In contrast, the impact of land surface anomalies, especially soil moisture and associated evaporation, has been proven notably difficult to demonstrate. The Noah Land Surface Model (LSM) is the land component of NCEP CFS version 2 (CFSv2) used for seasonal predictions. The Noah LSM originates from the Oregon State University (OSU) LSM. The evaporation control in the Noah LSM is based on the Penman-Monteith equation, which takes into account the solar radiation, relative humidity, air temperature, and soil moisture effects. The Noah LSM is configured with four soil layers with a fixed depth of 2 meters and free drainage at the bottom soil layer. This treatment assumes that the soil water table depth is well within the specified range, and also potentially misrepresents the soil moisture memory effects at seasonal time scales. To overcome the limitation, an unconfined aquifer is attached to the bottom of the soil to allow the water table to move freely up and down. In addition, in conjunction with the water table, an alternative Ball-Berry photosynthesis-based evaporation parameterization is examined to evaluate the impact from using a different evaporation control methodology. Focusing on the 2011 and 2012 intense summer droughts in the central US, seasonal ensemble forecast experiments with early May initial conditions are carried out for the two years using an enhanced version of CFSv2, where the atmospheric component of the CFSv2 is

  14. Cool seasons are related to poor prognosis in patients with infective endocarditis

    Science.gov (United States)

    Chen, Su-Jung; Chao, Tze-Fan; Lin, Yenn-Jiang; Lo, Li-Wei; Hu, Yu-Feng; Tuan, Ta-Chuan; Hsu, Tsui-Lieh; Yu, Wen-Chung; Leu, Hsin-Bang; Chang, Shih-Lin; Chen, Shih-Ann

    2012-09-01

    Many cardiac diseases demonstrate seasonal variations in the incidence and mortality. This study was designed to investigate whether the mortality of infective endocarditis (IE) was higher in cool seasons and to evaluate the effects of cool climate for IE. We enrolled 100 IE patients with vegetations in our hospital. The temperatures of the IE episodes were defined as the monthly average temperatures of the admission days. The average temperatures in the cool (fall/winter) and warm seasons (spring/summer) were 19.2°C and 27.6°C, respectively. In addition, patients admitted with the diagnosis of IE were identified from the National Health Insurance Research Database (NHIRD) and the in-hospital mortality rates in cool and warm seasons were compared to validate the findings derived from the data of our hospital. The mortality rate for IE was significantly higher in fall/winter than in spring/summer which presents consistently in the patient population of our hospital (32.7% versus 12.5%, p = 0.017) and from NHIRD (10.4% versus 4.6%, p = 0.019). IE episodes which occurred during cool seasons presented with a higher rate of heart failure (44.2% versus 22.9%, p = 0.025) and D-dimer level (5.5 ± 3.8 versus 2.4 ± 1.8 μg/ml, p = 0.017) at admission than that of warm seasons. These results may reflect the impact of temperatures during the pre-hospitalized period on the disease process. In the multivariate analysis, Staphylococcal infection, left ventricular hypertrophy, left ventricular systolic dysfunction and temperature were the independent predictors of mortalities in IE patients.

  15. The seasonal difference of Arctic warming and it's mechanism under sea ice cover diminishing%海冰消融背景下北极增温的季节差异及其原因探讨

    Institute of Scientific and Technical Information of China (English)

    武丰民; 何金海; 祁莉; 李文铠

    2014-01-01

    The sea ice concentration data ,atmospheric temperature data and surface sensible and latent heat net flux data from HadISST1 ,ERA-Interim and NCEP respectively are examined to investigate the seasonal and spatial distribution variation of the diminishing Arctic sea ice from 1979 to 2011 .Moreover ,the seasonal atmospheric tem-perature change responding to Arctic sea ice loss are discussed by analyzing surface albedo feedback ,surface sensi-ble and latent heat net flux .Results show that the strongest surface warming occurs in winter and fall and the lar-gest sea ice reduction takes place in summer and fall .Note that the weakest surface warming occurs in summer . This is principally due to the sea ice melt in summer which absorbs latent heat and the warmer lower atmosphere than ocean surface .With the decreasing sea ice ,more heat is transferred from the atmosphere to ocean leading to the ice-melt and upper level sea temperature warming .As a result ,the near-surface warming is modest in summer . By contrast ,sea ice refreezes in winter and fall and releases latent heat .Meanwhile ,less ice cover causes more heat transferred from ocean to atmosphere which warms the low level air .This delayed warming effect plays an impor-tant role in the different seasonal air temperature change in Arctic .Besides ,the regions of largest warming are co-located with those of greatest sea ice reductions .The southeast Arctic and northern Barents Sea are the key areas of the air-sea interaction in fall and winter ,respectively .%运用哈德莱中心第一套海冰覆盖率(HadISST1)、欧洲中心(ERA_Interim)的温度以及NCEP第一套地表感热通量、潜热通量等资料,研究了1979-2011年33 a来北极海冰消融的季节特点和空间特征,并从反照率---温度正反馈与地表感热通量、潜热通量等方面分析了海冰减少对北极增温影响的季节差异。结果表明,北极海冰在秋季和夏季的减少范围明显大于冬季

  16. Warm season precipitation signal in δ(2) H values of wood lignin methoxyl groups from high elevation larch trees in Switzerland.

    Science.gov (United States)

    Riechelmann, Dana F C; Greule, Markus; Siegwolf, Rolf T W; Anhäuser, Tobias; Esper, Jan; Keppler, Frank

    2017-10-15

    In this study, we tested stable hydrogen isotope ratios of wood lignin methoxyl groups (δ(2) Hmethoxyl values) as a palaeoclimate proxy in dendrochronology. This is a quite new method in the field of dendrochronology and the sample preparation is much simpler than the methods used before to measure δ(2) H values from wood. We measured δ(2) Hmethoxyl values in high elevation larch trees (Larix decidua Mill.) from Simplon Valley (southern Switzerland). Thirty-seven larch trees were sampled and five individuals analysed for their δ(2) Hmethoxyl values at annual (1971-2009) and pentadal resolution (1746-2009). The δ(2) Hmethoxyl values were measured as CH3 I released upon treatment of the dried wood samples with hydroiodic acid. 10-90 μL from the head-space were injected into the gas chromatography/high-temperature conversion/isotope ratio mass spectrometry (GC/HTC-IRMS) system. Testing the climate response of the δ(2) Hmethoxyl values, the annually resolved series show a positive correlation of r = 0.60 with June/July precipitation. The pentadally resolved δ(2) Hmethoxyl series do not show any significant correlation to climate parameters. Increased precipitation during June and July, which are on average warm and relatively dry months, results in higher δ(2) H values of the xylem water and, therefore, higher δ(2) H values in the lignin methoxyl groups. Therefore, we suggest that δ(2) Hmethoxyl values of high elevation larch trees might serve as a summer precipitation proxy. Copyright © 2017 John Wiley & Sons, Ltd.

  17. Warm Inflation

    Directory of Open Access Journals (Sweden)

    Øyvind Grøn

    2016-09-01

    Full Text Available I show here that there are some interesting differences between the predictions of warm and cold inflation models focusing in particular upon the scalar spectral index n s and the tensor-to-scalar ratio r. The first thing to be noted is that the warm inflation models in general predict a vanishingly small value of r. Cold inflationary models with the potential V = M 4 ( ϕ / M P p and a number of e-folds N = 60 predict δ n s C ≡ 1 − n s ≈ ( p + 2 / 120 , where n s is the scalar spectral index, while the corresponding warm inflation models with constant value of the dissipation parameter Γ predict δ n s W = [ ( 20 + p / ( 4 + p ] / 120 . For example, for p = 2 this gives δ n s W = 1.1 δ n s C . The warm polynomial model with Γ = V seems to be in conflict with the Planck data. However, the warm natural inflation model can be adjusted to be in agreement with the Planck data. It has, however, more adjustable parameters in the expressions for the spectral parameters than the corresponding cold inflation model, and is hence a weaker model with less predictive force. However, it should be noted that the warm inflation models take into account physical processes such as dissipation of inflaton energy to radiation energy, which is neglected in the cold inflationary models.

  18. Analysis on S Drought Index Variation in Warm Season for Altay Area in Xinjiang%新疆阿勒泰地区暖季S干旱指数变化特征分析

    Institute of Scientific and Technical Information of China (English)

    庄晓翠; 赵正波; 杨森; 张林梅

    2011-01-01

    运用新疆阿勒泰地区1961 - 2009年7个测站暖季(4- 10月)月降水量与无降水日数定义了S干旱指数,采用Mann-Kendall趋势检验法、Morlet小波变换对该指数进行了分析.结果表明:S指数能较好地反映阿勒泰地区的干旱情况.暖季近49a来极端干旱和极端湿润出现了3a和1a;区域中,东部两站无极端干旱年,其它站有极端干旱年;布尔津和吉木乃站有1a和2a的极端湿润年,其它站无极端湿润年.各季中,春秋季分别出现了2a和1a极端干旱年,无极端湿润年;夏季出现了2a极端干旱年和3a极端湿润年;各区域极端干旱和极端湿润年分布较复杂.暖季20世纪80、90年代以湿润为主,其它时间以干旱为主;春季60年代以干旱为主,其它时间以湿润为主;夏季年代变化基本与暖季一致;秋季60、80年代以湿润为主,其它时间以干旱为主.该地区暖季及各季S指数趋势变化不显著.小波分析表明,S指数存在着明显不同的年代际和年际尺度的周期变化.%S drought index was established and analyzed by using Mann-Kendall drift test method and Morlet small wave transformation, based on monthly precipitation and non-precipitation day's number from 7 meteorological stations in warm season (April to October) from 1961 to 2009 in Altay, Xinjiang. The results showed that S drought index accorded with drought condition in Altay. There were 3 extreme drought years and 1 extreme wetness year in last 49 years, there were extreme drought years except for 2 east stations. There were 1 extreme wetness year in Burgin and 2 extreme wetness years in Jimunai, and not in other stations. There were 2 extreme drought years in spring and 1 extreme drought year in autumn, but no extreme wetness years. There were 2 extreme drought years and 3 extreme wetness years in summer. Wetness dominated in warm season during 1980s and 1990s, and drought usually in other time; drought dominated in spring during 1960s

  19. Variability in warm-season atmospheric circulation and precipitation patterns over subtropical South America: relationships between the South Atlantic convergence zone and large-scale organized convection over the La Plata basin

    Science.gov (United States)

    Mattingly, Kyle S.; Mote, Thomas L.

    2017-01-01

    Warm-season precipitation variability over subtropical South America is characterized by an inverse relationship between the South Atlantic convergence zone (SACZ) and precipitation over the central and western La Plata basin of southeastern South America. This study extends the analysis of this "South American Seesaw" precipitation dipole to relationships between the SACZ and large, long-lived mesoscale convective systems (LLCSs) over the La Plata basin. By classifying SACZ events into distinct continental and oceanic categories and building a logistic regression model that relates LLCS activity across the region to continental and oceanic SACZ precipitation, a detailed account of spatial variability in the out-of-phase coupling between the SACZ and large-scale organized convection over the La Plata basin is provided. Enhanced precipitation in the continental SACZ is found to result in increased LLCS activity over northern, northeastern, and western sections of the La Plata basin, in association with poleward atmospheric moisture flux from the Amazon basin toward these regions, and a decrease in the probability of LLCS occurrence over the southeastern La Plata basin. Increased oceanic SACZ precipitation, however, was strongly related to reduced atmospheric moisture and decreased probability of LLCS occurrence over nearly the entire La Plata basin. These results suggest that continental SACZ activity and large-scale organized convection over the northern and eastern sections of the La Plata basin are closely tied to atmospheric moisture transport from the Amazon basin, while the warm coastal Brazil Current may also play an important role as an evaporative moisture source for LLCSs over the central and western La Plata basin.

  20. Variability in warm-season atmospheric circulation and precipitation patterns over subtropical South America: relationships between the South Atlantic convergence zone and large-scale organized convection over the La Plata basin

    Science.gov (United States)

    Mattingly, Kyle S.; Mote, Thomas L.

    2016-03-01

    Warm-season precipitation variability over subtropical South America is characterized by an inverse relationship between the South Atlantic convergence zone (SACZ) and precipitation over the central and western La Plata basin of southeastern South America. This study extends the analysis of this "South American Seesaw" precipitation dipole to relationships between the SACZ and large, long-lived mesoscale convective systems (LLCSs) over the La Plata basin. By classifying SACZ events into distinct continental and oceanic categories and building a logistic regression model that relates LLCS activity across the region to continental and oceanic SACZ precipitation, a detailed account of spatial variability in the out-of-phase coupling between the SACZ and large-scale organized convection over the La Plata basin is provided. Enhanced precipitation in the continental SACZ is found to result in increased LLCS activity over northern, northeastern, and western sections of the La Plata basin, in association with poleward atmospheric moisture flux from the Amazon basin toward these regions, and a decrease in the probability of LLCS occurrence over the southeastern La Plata basin. Increased oceanic SACZ precipitation, however, was strongly related to reduced atmospheric moisture and decreased probability of LLCS occurrence over nearly the entire La Plata basin. These results suggest that continental SACZ activity and large-scale organized convection over the northern and eastern sections of the La Plata basin are closely tied to atmospheric moisture transport from the Amazon basin, while the warm coastal Brazil Current may also play an important role as an evaporative moisture source for LLCSs over the central and western La Plata basin.

  1. Warming and provenance limit tree recruitment across and beyond the elevation range of subalpine forest

    Science.gov (United States)

    Kueppers, Lara M.; Conlisk, Erin; Castanha, Cristina; Moyes, Andrew B.; Germino, Matthew; de Valpine, Perry; Torn, Margaret S.; Mitton, Jeffry B.

    2017-01-01

    Climate niche models project that subalpine forest ranges will extend upslope with climate warming. These projections assume that the climate suitable for adult trees will be adequate for forest regeneration, ignoring climate requirements for seedling recruitment, a potential demographic bottleneck. Moreover, local genetic adaptation is expected to facilitate range expansion, with tree populations at the upper forest edge providing the seed best adapted to the alpine. Here, we test these expectations using a novel combination of common gardens, seeded with two widely distributed subalpine conifers, and climate manipulations replicated at three elevations. Infrared heaters raised temperatures in heated plots, but raised temperatures more in the forest than at or above treeline because strong winds at high elevation reduced heating efficiency. Watering increased season-average soil moisture similarly across sites. Contrary to expectations, warming reduced Engelmann spruce recruitment at and above treeline, as well as in the forest. Warming reduced limber pine first-year recruitment in the forest, but had no net effect on fourth-year recruitment at any site. Watering during the snow-free season alleviated some negative effects of warming, indicating that warming exacerbated water limitations. Contrary to expectations of local adaptation, low-elevation seeds of both species initially recruited more strongly than high-elevation seeds across the elevation gradient, although the low-provenance advantage diminished by the fourth year for Engelmann spruce, likely due to small sample sizes. High- and low-elevation provenances responded similarly to warming across sites for Engelmann spruce, but differently for limber pine. In the context of increasing tree mortality, lower recruitment at all elevations with warming, combined with lower quality, high-provenance seed being most available for colonizing the alpine, portends range contraction for Engelmann spruce. The lower

  2. Rapid warming accelerates tree growth decline in semi-arid forests of Inner Asia.

    Science.gov (United States)

    Liu, Hongyan; Park Williams, A; Allen, Craig D; Guo, Dali; Wu, Xiuchen; Anenkhonov, Oleg A; Liang, Eryuan; Sandanov, Denis V; Yin, Yi; Qi, Zhaohuan; Badmaeva, Natalya K

    2013-08-01

    Forests around the world are subject to risk of high rates of tree growth decline and increased tree mortality from combinations of climate warming and drought, notably in semi-arid settings. Here, we assess how climate warming has affected tree growth in one of the world's most extensive zones of semi-arid forests, in Inner Asia, a region where lack of data limits our understanding of how climate change may impact forests. We show that pervasive tree growth declines since 1994 in Inner Asia have been confined to semi-arid forests, where growing season water stress has been rising due to warming-induced increases in atmospheric moisture demand. A causal link between increasing drought and declining growth at semi-arid sites is corroborated by correlation analyses comparing annual climate data to records of tree-ring widths. These ring-width records tend to be substantially more sensitive to drought variability at semi-arid sites than at semi-humid sites. Fire occurrence and insect/pathogen attacks have increased in tandem with the most recent (2007-2009) documented episode of tree mortality. If warming in Inner Asia continues, further increases in forest stress and tree mortality could be expected, potentially driving the eventual regional loss of current semi-arid forests.

  3. Global Warming on Triton

    Science.gov (United States)

    Elliot, J. L.; Hammel, H. B.; Wasserman, L. H.; Franz, O. G.; McDonald, S. W.; Person, M. J.; Olkin, C. B.; Dunham, E. J.; Spencer, J. R.; Stansberry, J. A.; Buie, M. W.; Pasachoff, J. M.; Babcock, B. A.; McConnochie, T. H.

    1998-01-01

    Triton, Neptune's largest moon, has been predicted to undergo significant seasonal changes that would reveal themselves as changes in its mean frost temperature. But whether this temperature should at the present time be increasing, decreasing or constant depends on a number of parameters (such as the thermal properties of the surface, and frost migration patterns) that are unknown. Here we report observations of a recent stellar occultation by Triton which, when combined with earlier results, show that Triton has undergone a period of global warming since 1989. Our most conservative estimates of the rate of temperature and surface-pressure increase during this period imply that the atmosphere is doubling in bulk every 10 years, significantly faster than predicted by any published frost model for Triton. Our result suggests that permanent polar caps on Triton play a c dominant role in regulating seasonal atmospheric changes. Similar processes should also be active on Pluto.

  4. THE CLIMATE FEATURES OF THE SOUTH CHINA SEA WARM POOL

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    There exists a warm pool in the South China Sea (SCS). The temporal and spatial distribution and evolution of SCS warm pool is investigated using water temperatures at a depth of 20 m in the sea. The formation of the warm pool is discussed by combining water temperatures with geostrophic currents and simulated oceanic circulation. It is found that there are significant seasonal and interannual changes in the warm pool and in association with the general circulation of the atmosphere. The development of SCS warm pool is also closely related to the gyre activities in the sea and imported warm water from Indian Ocean (Java Sea) besides radiative warming.

  5. Global warming

    Science.gov (United States)

    Houghton, John

    2005-06-01

    'Global warming' is a phrase that refers to the effect on the climate of human activities, in particular the burning of fossil fuels (coal, oil and gas) and large-scale deforestation, which cause emissions to the atmosphere of large amounts of 'greenhouse gases', of which the most important is carbon dioxide. Such gases absorb infrared radiation emitted by the Earth's surface and act as blankets over the surface keeping it warmer than it would otherwise be. Associated with this warming are changes of climate. The basic science of the 'greenhouse effect' that leads to the warming is well understood. More detailed understanding relies on numerical models of the climate that integrate the basic dynamical and physical equations describing the complete climate system. Many of the likely characteristics of the resulting changes in climate (such as more frequent heat waves, increases in rainfall, increase in frequency and intensity of many extreme climate events) can be identified. Substantial uncertainties remain in knowledge of some of the feedbacks within the climate system (that affect the overall magnitude of change) and in much of the detail of likely regional change. Because of its negative impacts on human communities (including for instance substantial sea-level rise) and on ecosystems, global warming is the most important environmental problem the world faces. Adaptation to the inevitable impacts and mitigation to reduce their magnitude are both necessary. International action is being taken by the world's scientific and political communities. Because of the need for urgent action, the greatest challenge is to move rapidly to much increased energy efficiency and to non-fossil-fuel energy sources.

  6. Experimental climate warming decreases photosynthetic efficiency of lichens in an arid South African ecosystem.

    Science.gov (United States)

    Maphangwa, Khumbudzo Walter; Musil, Charles F; Raitt, Lincoln; Zedda, Luciana

    2012-05-01

    Elevated temperatures and diminished precipitation amounts accompanying climate warming in arid ecosystems are expected to have adverse effects on the photosynthesis of lichen species sensitive to elevated temperature and/or water limitation. This premise was tested by artificially elevating temperatures (increase 2.1-3.8°C) and reducing the amounts of fog and dew precipitation (decrease 30.1-31.9%), in an approximation of future climate warming scenarios, using transparent hexagonal open-top warming chambers placed around natural populations of four lichen species (Xanthoparmelia austroafricana, X. hyporhytida , Xanthoparmelia. sp., Xanthomaculina hottentotta) at a dry inland site and two lichen species (Teloschistes capensis and Ramalina sp.) at a humid coastal site in the arid South African Succulent Karoo Biome. Effective photosynthetic quantum yields ([Formula: see text]) were measured hourly throughout the day at monthly intervals in pre-hydrated lichens present in the open-top warming chambers and in controls which comprised demarcated plots of equivalent open-top warming chamber dimensions constructed from 5-cm-diameter mesh steel fencing. The cumulative effects of the elevated temperatures and diminished precipitation amounts in the open-top warming chambers resulted in significant decreases in lichen [Formula: see text]. The decreases were more pronounced in lichens from the dry inland site (decline 34.1-46.1%) than in those from the humid coastal site (decline 11.3-13.7%), most frequent and prominent in lichens at both sites during the dry summer season, and generally of greatest magnitude at or after the solar noon in all seasons. Based on these results, we conclude that climate warming interacting with reduced precipitation will negatively affect carbon balances in endemic lichens by increasing desiccation damage and reducing photosynthetic activity time, leading to increased incidences of mortality.

  7. Seasonality of reproductive events and early mortality in a colony of hamadryas baboons (Papio hamadryas hamadryas) over a 30-year period: Capital breeding and life history patterns in a food-provisioned population seasonally thermally stressed.

    Science.gov (United States)

    Polo, Pablo; Colmenares, Fernando

    2016-11-01

    In environments where energy demands and resource availability vary seasonally, individuals are expected to time the optimal allocation of resources to support survival and reproduction. Although female baboons are regarded as all year round, capital breeders, we wondered how they would respond in an ecological scenario where food were not limiting, foraging effort were negligible, and they were thermally stressed during the cold winter. This study analyzes a 30-year database of conceptions, births, resumptions of postlactational ovarian activity, menarches, and prenatal and early postnatal reproductive failures recorded in a food-provisioned colony of hamadryas baboons located in a temperate zone (40°25'N) to search for seasonal patterns in their life-history patterns and explore its fitness consequences. The results show that the study females exhibited moderate seasonality and behaved like capital breeders; ovarian activity peaked during the period of benign weather conditions (spring and early summer) and births and lactation peaked during the period when they were thermally stressed and faced a negative energy balance (winter). Mistimed conceptions were more likely to fail than timed conceptions were, although this association could be artefactual due to the difficulty to accurately detect prenatal losses. Insolation and, to a lesser extent, temperature were positively associated with conceptions, resumptions of postlactational ovarian activity and onsets of menarche, and negatively associated with births. These findings highlight the extent of plasticity (width of peaks) and resiliency (retention of a capital breeding tactic even under highly seasonally thermally stressful cold conditions) in how primates can adjust their life history patterns and solve tradeoffs in a scenario of strong seasonal variation. Am. J. Primatol. 78:1149-1164, 2016. © 2016 Wiley Periodicals, Inc.

  8. Ethnicity, deprivation and mortality due to 2009 pandemic influenza A(H1N1) in England during the 2009/2010 pandemic and the first post-pandemic season.

    Science.gov (United States)

    Zhao, H; Harris, R J; Ellis, J; Pebody, R G

    2015-12-01

    The relationship between risk of death following influenza A(H1N1)pdm09 infection and ethnicity and deprivation during the 2009/2010 pandemic period and the first post-pandemic season of 2010/2011 in England was examined. Poisson regression models were used to estimate the mortality risk, adjusted for age, gender, and place of residence. Those of non-White ethnicity experienced an increased mortality risk compared to White populations during the 2009/2010 pandemic [10·5/1000 vs. 6·0/1000 general population; adjusted risk ratio (RR) 1·84, 95% confidence interval (CI) 1·39-2·54] with the highest risk in those of Pakistani ethnicity. However, no significant difference between ethnicities was observed during the following 2010/2011 season. Persons living in areas with the highest level of deprivation had a significantly higher risk of death (RR 2·08, 95% CI 1·49-2·91) compared to the lowest level for both periods. These results highlight the importance of rapid identification of groups at higher risk of severe disease in the early stages of future pandemics to enable the implementation of optimal prevention and control measures for vulnerable populations.

  9. Global warming

    CERN Document Server

    Hulme, M

    1998-01-01

    Global warming-like deforestation, the ozone hole and the loss of species- has become one of the late 20the century icons of global environmental damage. The threat, is not the reality, of such a global climate change has motivated governments. businesses and environmental organisations, to take serious action ot try and achieve serious control of the future climate. This culminated last December in Kyoto in the agreement for legally-binding climate protocol. In this series of three lectures I will provide a perspective on the phenomenon of global warming that accepts the scientific basis for our concern, but one that also recognises the dynamic interaction between climate and society that has always exited The future will be no different. The challenge of global warning is not to pretend it is not happening (as with some pressure groups), nor to pretend it threatens global civilisation (as with other pressure groups), and it is not even a challenge to try and stop it from happening-we are too far down the ro...

  10. Warm Breeze

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Middle-aged female painter Wang Yingchun is a first-grade artist at the Research Instituteof Chinese Painting. With a solid foundation in: Chinese painting, oil painting andsculpture she began to experiment in the early 1980s with stone carving, murals, folkart, landscapes, flowers and birds, cubism, expressionism and abstractionism. Living ina time of social transformation, she felt pressed to create her own artistic style. Aftervisiting South America, she produced a batch of works which drew the essence of theBeast Group and used a new technique, without sketching the contours of flowers, sothat the paintings look wild, romantic and exuberant. This painting Warm Breeze displaysWang’s style: While extensively studying the paintings of various schools, she makes hertraditional Chinese ink paintings tinted with modern color.

  11. Climate Warming Threatens Semi-arid Forests in Inner Asia

    Science.gov (United States)

    WU, X.; Liu, H.; Qi, Z.; Li, X.

    2014-12-01

    A line of evidences reveal an increasing tree growth decline and tree mortality mainly attributable to climate warming and the warming-mediated changes in drought and other processes (such as fire and insect dynamics) in many parts of world tropical, temperate and boreal forests. However, the growth responses to climate change of the widely distributed semi-arid forests are unclear. Here, we synthetically investigate the tree growth patterns during past decades and its interannual response to climate variations in Inner Asia combining the ground truth field survey and samplings, remote sensing observations and climate data. We identified a pervasive tree growth decline since mid-1990s in semi-arid forests in Inner Asia. The widely observed tree growth decline is dominantly attributable to warming-induced water stress during pre- and early growing season. Tree growth of semi-arid forests in Inner Asia is particularly susceptible to spring warming and has been suffering a prolonged growth limitation in recent decades due to spring warming-mediated water conditions. Additionally, we identified a much slower growth rate in younger trees and a lack of tree regeneration in these semi-arid forests. The widely observed forest growth reduction and lack of tree regeneration over semi-arid forests in Inner Asia could predictably exert great effects on forest structure, regionally/globally biophysical and biochemical processes and the feedbacks between biosphere and atmosphere. Notably, further increases in forest stress and tree mortality could be reasonably expected, especially in context of the increase frequency and severity of high temperature and heat waves and changes in forest disturbances, potentially driving the eventual regional loss of current semi-arid forests. Given the potential risks of climate induced forest dieback, increased management attention to adaptation options for enhancing forest resistance and resilience to projected climate stress can be expected

  12. Climate warming threatens semi-arid forests in Inner Asia

    Science.gov (United States)

    WU, X.

    2015-12-01

    A line of evidences reveal an increasing tree growth decline and tree mortality mainly attributable to climate warming and the warming-mediated changes in drought and other processes in many parts of world tropical, temperate and boreal forests. However, the growth responses to climate change of the widely distributed semi-arid forests are unclear. Here, we synthetically investigate the tree growth patterns during past decades and its interannual response to climate variations in Inner Asia combining the ground truth field survey and samplings, remote sensing observations and climate data. We identified a pervasive tree growth decline since mid-1990s in semi-arid forests in Inner Asia. The widely observed tree growth decline is dominantly attributable to warming-induced water stress during pre- and early growing season. Tree growth of semi-arid forests in Inner Asia is particularly susceptible to spring warming and has been suffering a prolonged growth limitation in recent decades due to spring warming-mediated water conditions. Additionally, we identified a much slower growth rate in younger trees and a lack of tree regeneration in these semi-arid forests. The widely observed forest growth reduction and lack of tree regeneration over semi-arid forests in Inner Asia could predictably exert great effects on forest structure, regionally/globally biophysical and biochemical processes and the feedbacks between biosphere and atmosphere. Notably, further increases in forest stress and tree mortality could be reasonably expected, especially in context of the increase frequency and severity of high temperature and heat waves and changes in forest disturbances, potentially driving the eventual regional loss of current semi-arid forests. Given the potential risks of climate induced forest dieback, increased management attention to adaptation options for enhancing forest resistance and resilience to projected climate stress can be expected. However, the functionally realistic

  13. Mortality in Spain during the heat waves of summer 2003.

    Science.gov (United States)

    Simón, F; Lopez-Abente, G; Ballester, E; Martínez, F

    2005-07-01

    The effect of the elevated temperatures on mortality experienced in Europe during the summer of 2003 was observed in several countries. This study, carried out in Spain, describes mortality between 1 June and 31 August and evaluates the effect of the heat wave on mortality. Observed deaths were obtained from official death registers from 50 provincial capitals. Observed deaths were compared with the expected number, estimated by applying a Poisson regression model to historical mortality series and adjusting for the upward trend and seasonality observed. Meteorological information was provided by the Instituto Nacional de Meteorologia (National Institute of Meteorology). Spain experienced three heat waves in 2003. The total associated excess deaths were 8% (43 212 observed deaths compared with 40 046 expected deaths). Excess deaths were only observed in those aged 75 years and over (15% more deaths than expected for the age group 75 to 84 and 29% for those aged 85 or over). This phenomenon (heat-associated excess mortality) is an emerging public health problem because of its increasing attributable risk, the aging of the Spanish population and its forecasted increasing frequency due to global warming. The implementation of alert and response systems based on monitoring of climate-related risks, emergency room activity and mortality, and strengthening the response capacity of the social and health services should be considered.

  14. Local Warming

    CERN Document Server

    Vanderbei, Robert J

    2012-01-01

    Using 55 years of daily average temperatures from a local weather station, I made a least-absolute-deviations (LAD) regression model that accounts for three effects: seasonal variations, the 11-year solar cycle, and a linear trend. The model was formulated as a linear programming problem and solved using widely available optimization software. The solution indicates that temperatures have gone up by about 2 degrees Fahrenheit over the 55 years covered by the data. It also correctly identifies the known phase of the solar cycle; i.e., the date of the last solar minimum. It turns out that the maximum slope of the solar cycle sinusoid in the regression model is about the same size as the slope produced by the linear trend. The fact that the solar cycle was correctly extracted by the model is a strong indicator that effects of this size, in particular the slope of the linear trend, can be accurately determined from the 55 years of data analyzed. The main purpose for doing this analysis is to demonstrate that it i...

  15. Multi-year objective analyses of warm season ground-level ozone and PM2.5 over North America using real-time observations and Canadian operational air quality models

    Science.gov (United States)

    Robichaud, A.; Ménard, R.

    2014-02-01

    Multi-year objective analyses (OA) on a high spatiotemporal resolution for the warm season period (1 May to 31 October) for ground-level ozone and for fine particulate matter (diameter less than 2.5 microns (PM2.5)) are presented. The OA used in this study combines model outputs from the Canadian air quality forecast suite with US and Canadian observations from various air quality surface monitoring networks. The analyses are based on an optimal interpolation (OI) with capabilities for adaptive error statistics for ozone and PM2.5 and an explicit bias correction scheme for the PM2.5 analyses. The estimation of error statistics has been computed using a modified version of the Hollingsworth-Lönnberg (H-L) method. The error statistics are "tuned" using a χ2 (chi-square) diagnostic, a semi-empirical procedure that provides significantly better verification than without tuning. Successful cross-validation experiments were performed with an OA setup using 90% of data observations to build the objective analyses and with the remainder left out as an independent set of data for verification purposes. Furthermore, comparisons with other external sources of information (global models and PM2.5 satellite surface-derived or ground-based measurements) show reasonable agreement. The multi-year analyses obtained provide relatively high precision with an absolute yearly averaged systematic error of less than 0.6 ppbv (parts per billion by volume) and 0.7 μg m-3 (micrograms per cubic meter) for ozone and PM2.5, respectively, and a random error generally less than 9 ppbv for ozone and under 12 μg m-3 for PM2.5. This paper focuses on two applications: (1) presenting long-term averages of OA and analysis increments as a form of summer climatology; and (2) analyzing long-term (decadal) trends and inter-annual fluctuations using OA outputs. The results show that high percentiles of ozone and PM2.5 were both following a general decreasing trend in North America, with the eastern

  16. Narrative warm/cold variations in continental western Europe, AD 708-1426

    Institute of Scientific and Technical Information of China (English)

    严中伟; Pierre Alexandre; Gaston Demaree

    1997-01-01

    An extended narrative dataset of the Medieval time AD 708-1426 in continental western Europe was set up. Some 30-year-moving mean seasonal temperature deviation series were reconstructed. A warming trend occurred around AD 1200. During the warm stage, seasonal cycle might be weak due to frequent cool summers. Significant warm summer conditions did not occur until the late 14th century, when the annual temperature level began decreasing. The mean warm season temperature level during the late 14th to the early 15th century might be about 0.3℃ higher than the present. It was suggested to cautiously comment on historical climates for different seasons.

  17. The intrinsic growth rate as a predictor of population viability under climate warming.

    Science.gov (United States)

    Amarasekare, Priyanga; Coutinho, Renato M

    2013-11-01

    1. Lately, there has been interest in using the intrinsic growth rate (rm) to predict the effects of climate warming on ectotherm population viability. However, because rm is calculated using the Euler-Lotka equation, its reliability in predicting population persistence depends on whether ectotherm populations can achieve a stable age/stage distribution in thermally variable environments. Here, we investigate this issue using a mathematical framework that incorporates mechanistic descriptions of temperature effects on vital rates into a stage-structured population model that realistically captures the temperature-induced variability in developmental delays that characterize ectotherm life cycles. 2. We find that populations experiencing seasonal temperature variation converge to a stage distribution whose intra-annual pattern remains invariant across years. As a result, the mean annual per capita growth rate also remains constant between years. The key insight is the mechanism that allows populations converge to a stationary stage distribution. Temperature effects on the biochemical processes (e.g. enzyme kinetics, hormonal regulation) that underlie life-history traits (reproduction, development and mortality) exhibit well-defined thermodynamical properties (e.g. changes in entropy and enthalpy) that lead to predictable outcomes (e.g. reduction in reaction rates or hormonal action at temperature extremes). As a result, life-history traits exhibit a systematic and predictable response to seasonal temperature variation. This in turn leads to temporally predictable temperature responses of the stage distribution and the per capita growth rate. 3. When climate warming causes an increase in the mean annual temperature and/or the amplitude of seasonal fluctuations, the population model predicts the mean annual per capita growth rate to decline to zero within 100 years when warming is slow relative to the developmental period of the organism (0.03-0.05°C per year) and to

  18. Seasonal Influenza: An Overview

    Science.gov (United States)

    Li, Christina; Freedman, Marian

    2009-01-01

    Seasonal influenza is a major cause of morbidity and mortality in the United States. It also has major social and economic consequences in the form of high rates of absenteeism from school and work as well as significant treatment and hospitalization costs. In fact, annual influenza epidemics and the resulting deaths and lost days of productivity…

  19. Seasonal Influenza: An Overview

    Science.gov (United States)

    Li, Christina; Freedman, Marian

    2009-01-01

    Seasonal influenza is a major cause of morbidity and mortality in the United States. It also has major social and economic consequences in the form of high rates of absenteeism from school and work as well as significant treatment and hospitalization costs. In fact, annual influenza epidemics and the resulting deaths and lost days of productivity…

  20. Growth and physiological responses of three warm-season turfgrasses to lead stress%铅胁迫对三种暖季型草坪草生长和生理特性的影响

    Institute of Scientific and Technical Information of China (English)

    李西; 吴亚娇; 孙凌霞

    2014-01-01

    In order to explore the mechanism of Pb accumulation and transportation in plant tissue,the growth and physiological responses of turfgrass under soil Pb stress were evaluated in a pot experiment with three warm-season turfgrass species:Eremochloaophiuroides (centipedegrass),Cynodondactylon (bermudagrass), and Zoysiaiaponica (zoysiagrass).By applying Pb of different concentrations to the soil,CK(0 mg/kg)and five Pb treatments as the following 250,500,1000,2000,4000 mg/kg were set in this experiment.Our results showed that there is a significant decrease of the visual quality and leaf relative water content under 4000 mg/kg treatment comparing with control.Leaf chlorophyll a and b content significantly reduced under 4000 mg/kg treatment comparing with control among all three turfgrasses.The electrolyte leakage in leave gradually rises with the increase of Pb level among all three turfgrasses.These results suggested that cell membrane of leave is damaged by application of Pb.The antioxidant defense system (superoxide dismutase/SOD,catalase/CAT, peroxidase/POD)was greatly activated under the various Pb stress among three turfgrasses species.Under all four Pb treatments in centipedgrass,the activity of SOD gradually rises and reaches a maximum at 20 day after Pb application,and the activity of CAT at day 5 after Pb treatment is greatly higher than that in control.While the activity of POD increases significantly only under 2000 and 4000 mg/kg Pb treatments and reaches the max-imum at day 15 after Pb application in centipedigrass.Under all four Pb treatments in bermudagrass,the activ-ity of SOD rises at day 5 after Pb treatment and boosts a maximum at day 25 ,and the activity of CAT reaches a maximum at 15 day after treatment.While the activity of POD in Pb treatments rises gradually with the accu-mulation of Pb in soil and reaches a maximum at day 30 in all Pb treatments.The activity of SOD is significant-ly higher under 4000 mg/kg treatment than that in control and

  1. Sudden Stratospheric Warming Compendium

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sudden Stratospheric Warming Compendium (SSWC) data set documents the stratospheric, tropospheric, and surface climate impacts of sudden stratospheric warmings. This...

  2. Global metabolic impacts of recent climate warming.

    Science.gov (United States)

    Dillon, Michael E; Wang, George; Huey, Raymond B

    2010-10-07

    Documented shifts in geographical ranges, seasonal phenology, community interactions, genetics and extinctions have been attributed to recent global warming. Many such biotic shifts have been detected at mid- to high latitudes in the Northern Hemisphere-a latitudinal pattern that is expected because warming is fastest in these regions. In contrast, shifts in tropical regions are expected to be less marked because warming is less pronounced there. However, biotic impacts of warming are mediated through physiology, and metabolic rate, which is a fundamental measure of physiological activity and ecological impact, increases exponentially rather than linearly with temperature in ectotherms. Therefore, tropical ectotherms (with warm baseline temperatures) should experience larger absolute shifts in metabolic rate than the magnitude of tropical temperature change itself would suggest, but the impact of climate warming on metabolic rate has never been quantified on a global scale. Here we show that estimated changes in terrestrial metabolic rates in the tropics are large, are equivalent in magnitude to those in the north temperate-zone regions, and are in fact far greater than those in the Arctic, even though tropical temperature change has been relatively small. Because of temperature's nonlinear effects on metabolism, tropical organisms, which constitute much of Earth's biodiversity, should be profoundly affected by recent and projected climate warming.

  3. Declining impacts of hot spells on mortality in the Czech Republic: adaptation to climate change?

    Science.gov (United States)

    Kysely, Jan; Plavcova, Eva

    2010-05-01

    Extreme temperature events have pronounced negative impacts on ecosystems and society, including human health effects. The study examines temporal changes in mortality associated with spells of large positive temperature anomalies (hot spells) in the population of the Czech Republic (central Europe) during 1986-2006. Declining trends in the mortality impacts are found in summer as well as in transition seasons, in spite of rising temperature trends (warming by 1.4 deg. C in summer over the 21-year period). The finding remains unchanged if possible confounding effects of within-season acclimatization to heat and the mortality displacement effect are taken into account. Recent positive socio-economic development, following the collapse of communism in central and eastern Europe in 1989, and better public awareness of heat-related risks are likely the primary causes of the declining vulnerability. The results suggest that climate change may have relatively little influence on heat-related deaths, since changes in other factors that influence vulnerability of the population are dominant instead of temperature trends. It is essential to better understand the observed non-stationarity of the temperature-mortality relationship and the role of adaptation and its limits, both physiological and technological, and to address associated uncertainties in studies dealing with climate change projections of temperature-related mortality.

  4. 冷季暖棚对鄂尔多斯细毛羊体重及产毛性能影响的研究%Influence of Warm Shed Feeding Manner on Weight and Wool Production Performance of Ordos Fine Wool Sheep in Cold Season

    Institute of Scientific and Technical Information of China (English)

    谷英; 斯登丹巴; 姚江勇; 满都拉; 浪腾; 徐忠林; 王玮; 郑建峰

    2015-01-01

    为评价冷季暖棚饲养方式对鄂尔多斯细毛羊体重及产毛性能的影响,将选取的基础母羊、后备母羊、育成母羊、育成公羊分别随机分成试验组和对照组。各试验组于2012年12月7日—2013年1月31日,夜间圈入暖棚内饲养,对照组夜间在圈外饲养。记录冷季暖棚试验期间暖棚内、外夜间气温,比较各试验组及对照组在冷季暖棚试验期间的体重变化。冷季暖棚试验结束后,试验羊只继续饲喂至2013年6月初。试验结束时,分别测定并比较基础母羊、后备母羊、育成母羊的试验组及对照组产毛量、羊毛长度、羊毛细度。结果表明,冷季暖棚试验期内,圈内、外夜间平均气温相差9.76℃,圈内、外最低气温相差14.10℃;基础母羊、后备母羊、育成母羊试验组体重分别比对照组少下降3.57、2.98、2.74 kg,育成公羊试验组体重比照组多提高3.08 kg;基础母羊、后备母羊、育成母羊的试验组产毛量分别比对照组增加0.22 kg(P>0.05)、0.11 kg(P0.05);基础母羊、后备母羊、育成母羊的试验组羊毛长度分别比对照组增加0.40 cm(P>0.05)、0.31 cm(P>0.05)、0.25 cm(P>0.05);基础母羊、后备母羊、育成母羊试验组羊毛细度均比对照组细,且细度分别降低了0.01μm(P>0.05)、0.09μm(P>0.05)、0.24μm(P>0.05)。结果提示,冷季暖棚饲养方式可有效防止鄂尔多斯细毛羊掉膘,并可提高产毛量,增加羊毛长度,降低羊毛细度。%In order to evaluate the influence of warm shed feeding manner on weight and wool production performance of Ordos fine wool sheep in cold season, the selected basic ewe, reserved ewe, gimmer hogg and ram hogg were randomly divided into experimental group and control group, respectively. All of the experimental groups fed inside the warm shed at night from December 7 of 2012 to January 31 of 2013, whereas the control

  5. Dynamic response of wind turbine towers in warm permafrost

    Institute of Scientific and Technical Information of China (English)

    Benjamin Still; ZhaoHui Joey Yang; Simon Evans; FuJun Niu

    2014-01-01

    Wind is a great source of renewable energy in western Alaska. Consistent winds blow across the barren tundra underlain by warm permafrost in the winter season, when the energy demand is the highest. Foundation engineering in warm permafrost has always been a challenge in wind energy development. Degrading warm permafrost poses engineering issues to design, construction, and operation of wind turbines. This paper describes the foundation design of a wind turbine built in western Alaska. It presents a sys-tem for response monitoring and load assessment, and data collected from September 2013 to March 2014. The dynamic proper-ties are assessed based on the monitoring data, and seasonal changes in the dynamic properties of the turbine tower-foundation system and likely resonance between the spinning blades and the tower structure are discussed. These analyses of a wind turbine in warm permafrost are valuable for designing or retrofitting of foundations in warm permafrost.

  6. Occupational mortality

    DEFF Research Database (Denmark)

    Lynge, Elsebeth

    2011-01-01

    INTRODUCTION: This paper aims to present the methods and main results from the Danish occupational mortality studies, and to set the Danish studies into the international context of occupational mortality studies. RESEARCH TOPICS: The first Danish occupational mortality study from 1970...

  7. Experimental winter warming modifies thermal performance and primes acorn ants for warm weather

    DEFF Research Database (Denmark)

    MacLean, Heidi J.; Penick, Clint A.; Dunn, Robert R.

    2017-01-01

    The frequency of warm winter days is increasing under global climate change, but how organisms respond to warmer winters is not well understood. Most studies focus on growing season responses to warming. Locomotor performance is often highly sensitive to temperature, and can determine fitness...... outcomes through a variety of mechanisms including resource acquisition and predator escape. As a consequence, locomotor performance, and its impacts on fitness, may be strongly affected by winter warming in winter-active species. Here we use the acorn ant, Temnothorax curvispinosus, to explore how thermal...... performance (temperature-driven plasticity) in running speed is influenced by experimental winter warming of 3–5 °C above ambient in a field setting. We used running speed as a measure of performance as it is a common locomotor trait that influences acquisition of nest sites and food in acorn ants...

  8. The Tropical Western Hemisphere Warm Pool

    Science.gov (United States)

    Wang, C.; Enfield, D. B.

    2002-12-01

    The paper describes and examines variability of the tropical Western Hemisphere warm pool (WHWP) of water warmer than 28.5oC. The WHWP is the second-largest tropical warm pool on Earth. Unlike the Eastern Hemisphere warm pool in the western Pacific, which straddles the equator, the WHWP is entirely north of the equator. At various stages of development the WHWP extends over parts of the eastern North Pacific, the Gulf of Mexico, the Caribbean, and the western tropical North Atlantic. It has a large seasonal cycle and its interannual fluctuations of area and intensity are significant. Surface heat fluxes warm the WHWP through the boreal spring to an annual maximum of SST and WHWP area in the late summer/early fall, associated with eastern North Pacific and Atlantic hurricane activities and rainfall from northern South America to the southern tier of the United States. Observations suggest that a positive ocean-atmosphere feedback operating through longwave radiation and associated cloudiness seems to operate in the WHWP. During winter preceding large warm pool, there is an alteration of the Walker and Hadley circulation cells that serves as a "tropospheric bridge" for transferring Pacific ENSO effects to the Atlantic sector and inducing initial warming of warm pool. Associated with the warm SST anomalies is a decrease in sea level pressure anomalies and an anomalous increase in atmospheric convection and cloudiness. The increase in convective activity and cloudiness results in less net longwave radiation loss from the sea surface, which then reinforces SST anomalies.

  9. On Global Warming

    Institute of Scientific and Technical Information of China (English)

    Brad Franklin

    2010-01-01

    @@ There is a huge argument going on in the world these days and it is centered on the notion that our planet is warming up. It's celled global warming and it postulates1 that our use of fossil fuels such as coal and oil and our destruction of large areas of forest across the world have combined to create so-celled greenhouse gases.

  10. Keeping Warm Without Coal

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Heat-pump technology offers a clean heating alternative to coal With no air conditioning or indoor heating, families in southeast Beijing’s Fangzhuang neighbor-hood still enjoy refreshing warm air all year round. The secret is in the pump technology. Heat pumps cool the homes in summer and warm them in winter just like a central air-conditioning system.

  11. The phenology of Arctic Ocean surface warming

    Science.gov (United States)

    Steele, Michael; Dickinson, Suzanne

    2016-09-01

    In this work, we explore the seasonal relationships (i.e., the phenology) between sea ice retreat, sea surface temperature (SST), and atmospheric heat fluxes in the Pacific Sector of the Arctic Ocean, using satellite and reanalysis data. We find that where ice retreats early in most years, maximum summertime SSTs are usually warmer, relative to areas with later retreat. For any particular year, we find that anomalously early ice retreat generally leads to anomalously warm SSTs. However, this relationship is weak in the Chukchi Sea, where ocean advection plays a large role. It is also weak where retreat in a particular year happens earlier than usual, but still relatively late in the season, primarily because atmospheric heat fluxes are weak at that time. This result helps to explain the very different ocean warming responses found in two recent years with extreme ice retreat, 2007 and 2012. We also find that the timing of ice retreat impacts the date of maximum SST, owing to a change in the ocean surface buoyancy and momentum forcing that occurs in early August that we term the Late Summer Transition (LST). After the LST, enhanced mixing of the upper ocean leads to cooling of the ocean surface even while atmospheric heat fluxes are still weakly downward. Our results indicate that in the near-term, earlier ice retreat is likely to cause enhanced ocean surface warming in much of the Arctic Ocean, although not where ice retreat still occurs late in the season.

  12. Short-term effects of air pollution on daily mortality and years of life lost in Nanjing, China.

    Science.gov (United States)

    Lu, Feng; Zhou, Lian; Xu, Yan; Zheng, Tongzhang; Guo, Yuming; Wellenius, Gregory A; Bassig, Bryan A; Chen, Xiaodong; Wang, Haochen; Zheng, Xiaoying

    2015-12-01

    The deteriorating air quality in Chinese cities is attracting growing public concern. We conducted analyses to quantify the associations between daily changes in ambient air pollution and mortality in Nanjing, China. Daily mortality, air pollution, and meteorological data from 1 January 2009 to 31 December 2013 were collected. Over-dispersed Poisson regression models were used to evaluate the risk of daily non-accidental mortality and years of life lost (YLL) from exposure to respirable particulate matter (PM10) and gaseous pollutants (NO2, SO2). Stratified analysis was conducted to indentify the modifying effect of individual-level factors on the association between air pollutants and mortality. We found that interquartile range (IQR) increases in the two-day average of PM10, NO2 and SO2 were significantly associated with 1.6% [95% confidence interval (CI):0.7%-2.6%], 2.9% (95% CI: 1.7%-4.2%) and 2.4% (95% CI: 1.2%-3.6%) higher rates of non-accidental mortality; and related to YLL increases of 20.5 (95% CI: 6.3-34.8), 34.9 (95% CI: 16.9-52.9) and 30.3 (95% CI: 12.2-48.4) years, respectively; Associations between air pollution and mortality were more pronounced in the warm season than in the cool season. We conclude that the risks of mortality and YLL were elevated corresponding to an increase in current ambient concentrations of the air pollutants, and season may modify the effects of outdoor air pollution in Nanjing.

  13. Climate heterogeneity modulates impact of warming on tropical insects.

    Science.gov (United States)

    Bonebrake, Timothy C; Deutsch, Curtis A

    2012-03-01

    Evolutionary history and physiology mediate species responses to climate change. Tropical species that do not naturally experience high temperature variability have a narrow thermal tolerance compared to similar taxa at temperate latitudes and could therefore be most vulnerable to warming. However, the thermal adaptation of a species may also be influenced by spatial temperature variations over its geographical range. Spatial climate gradients, especially from topography, may also broaden thermal tolerance and therefore act to buffer warming impacts. Here we show that for low-seasonality environments, high spatial heterogeneity in temperature correlates significantly with greater warming tolerance in insects globally. Based on this relationship, we find that climate change projections of direct physiological impacts on insect fitness highlight the vulnerability of tropical lowland areas to future warming. Thus, in addition to seasonality, spatial heterogeneity may play a critical role in thermal adaptation and climate change impacts particularly in the tropics.

  14. How does the dengue vector mosquito Aedes albopictus respond to global warming?

    Science.gov (United States)

    Jia, Pengfei; Chen, Xiang; Chen, Jin; Lu, Liang; Liu, Qiyong; Tan, Xiaoyue

    2017-03-11

    Global warming has a marked influence on the life cycle of epidemic vectors as well as their interactions with human beings. The Aedes albopictus mosquito as the vector of dengue fever surged exponentially in the last decade, raising ecological and epistemological concerns of how climate change altered its growth rate and population dynamics. As the global warming pattern is considerably uneven across four seasons, with a confirmed stronger effect in winter, an emerging need arises as to exploring how the seasonal warming effects influence the annual development of Ae. albopictus. The model consolidates a 35-year climate dataset and designs fifteen warming patterns that increase the temperature of selected seasons. Based on a recently developed mechanistic population model of Ae. albopictus, the model simulates the thermal reaction of blood-fed adults by systematically increasing the temperature from 0.5 to 5 °C at an interval of 0.5 °C in each warming pattern. The results show the warming effects are different across seasons. The warming effects in spring and winter facilitate the development of the species by shortening the diapause period. The warming effect in summer is primarily negative by inhibiting mosquito development. The warming effect in autumn is considerably mixed. However, these warming effects cannot carry over to the following year, possibly due to the fact that under the extreme weather in winter the mosquito fully ceases from development and survives in terms of diapause eggs. As the historical pattern of global warming manifests seasonal fluctuations, this study provides corroborating and previously ignored evidence of how such seasonality affects the mosquito development. Understanding this short-term temperature-driven mechanism as one chain of the transmission events is critical to refining the thermal reaction norms of the epidemic vector under global warming as well as developing effective mosquito prevention and control strategies.

  15. Warm autoimmune hemolytic anemia.

    Science.gov (United States)

    Naik, Rakhi

    2015-06-01

    Warm autoimmune hemolytic anemia (AIHA) is defined as the destruction of circulating red blood cells (RBCs) in the setting of anti-RBC autoantibodies that optimally react at 37°C. The pathophysiology of disease involves phagocytosis of autoantibody-coated RBCs in the spleen and complement-mediated hemolysis. Thus far, treatment is aimed at decreasing autoantibody production with immunosuppression or reducing phagocytosis of affected cells in the spleen. The role of complement inhibitors in warm AIHA has not been explored. This article addresses the diagnosis, etiology, and treatment of warm AIHA and highlights the role of complement in disease pathology.

  16. Potential trends in snowmelt-generated peak streamflows in a warming climate

    Science.gov (United States)

    Wang, Rui; Kumar, Mukesh; Link, Timothy E.

    2016-05-01

    Previously reported impacts of climate warming on streamflow peaks are varied, and the controls on the variations remain unclear. Using physically based linked snowpack and watershed hydrological models, we evaluated the potential changes in seasonal snowmelt-generated streamflow peak (Qmax) due to warming in a small semiarid mountain watershed. Results suggest that the trend in Qmax with warming is strongly governed by the conversion of precipitation phase, accumulated snow amount prior to the melt season, and snowmelt rate during the ablation period. Under a warming climate, the trend in Qmax is expected to be decreasing for relatively warm regions but increasing for cold regions. Climate regimes that are most susceptible to dominant precipitation phase transitions from snow to rain are likely to experience larger decreases in Qmax with warming. This study serves as a first step toward assessing the varied impacts on Qmax due to warming vis-a-vis the specific catchment hydroclimatology.

  17. Intra-urban vulnerability to heat-related mortality in New York City, 1997–2006

    Science.gov (United States)

    Rosenthal, Joyce Klein; Kinney, Patrick L.; Metzger, Kristina B.

    2015-01-01

    The health impacts of exposure to summertime heat are a significant problem in New York City (NYC) and for many cities and are expected to increase with a warming climate. Most studies on heat-related mortality have examined risk factors at the municipal or regional scale and may have missed the intra-urban variation of vulnerability that might inform prevention strategies. We evaluated whether place-based characteristics (socioeconomic/demographic and health factors, as well as the built and biophysical environment) may be associated with greater risk of heat-related mortality for seniors during heat events in NYC. As a measure of relative vulnerability to heat, we used the natural cause mortality rate ratio among those aged 65 and over (MRR65+), comparing extremely hot days (maximum heat index 100 °F+) to all warm season days, across 1997–2006 for NYC's 59 Community Districts and 42 United Hospital Fund neighborhoods. Significant positive associations were found between the MRR65+ and neighborhood-level characteristics: poverty, poor housing conditions, lower rates of access to air-conditioning, impervious land cover, surface temperatures aggregated to the area-level, and seniors’ hypertension. Percent Black/African American and household poverty were strong negative predictors of seniors’ air conditioning access in multivariate regression analysis. PMID:25199872

  18. Intra-urban vulnerability to heat-related mortality in New York City, 1997-2006.

    Science.gov (United States)

    Klein Rosenthal, Joyce; Kinney, Patrick L; Metzger, Kristina B

    2014-11-01

    The health impacts of exposure to summertime heat are a significant problem in New York City (NYC) and for many cities and are expected to increase with a warming climate. Most studies on heat-related mortality have examined risk factors at the municipal or regional scale and may have missed the intra-urban variation of vulnerability that might inform prevention strategies. We evaluated whether place-based characteristics (socioeconomic/demographic and health factors, as well as the built and biophysical environment) may be associated with greater risk of heat-related mortality for seniors during heat events in NYC. As a measure of relative vulnerability to heat, we used the natural cause mortality rate ratio among those aged 65 and over (MRR65+), comparing extremely hot days (maximum heat index 100°F+) to all warm season days, across 1997-2006 for NYC's 59 Community Districts and 42 United Hospital Fund neighborhoods. Significant positive associations were found between the MRR65+ and neighborhood-level characteristics: poverty, poor housing conditions, lower rates of access to air-conditioning, impervious land cover, surface temperatures aggregated to the area-level, and seniors' hypertension. Percent Black/African American and household poverty were strong negative predictors of seniors' air conditioning access in multivariate regression analysis.

  19. Warm and Cool Dinosaurs.

    Science.gov (United States)

    Mannlein, Sally

    2001-01-01

    Presents an art activity in which first grade students draw dinosaurs in order to learn about the concept of warm and cool colors. Explains how the activity also helped the students learn about the concept of distance when drawing. (CMK)

  20. Global warming yearbook: 1998

    Energy Technology Data Exchange (ETDEWEB)

    Arris, L. [ed.

    1999-02-01

    The report brings together a year`s worth of global warming stories - over 280 in all - in one convenient volume. It provides a one-stop report on the scientific, political and industrial implications of global warming. The report includes: detailed coverage of negotiations on the Kyoto Protocol; scientific findings on carbon sources and sinks, coral bleaching, Antarctic ice shelves, plankton, wildlife and tree growth; new developments on fuel economy, wind power, fuel cells, cogeneration, energy labelling and emissions trading.

  1. Hurricane Season

    Institute of Scientific and Technical Information of China (English)

    JENNIFER; JETT

    2008-01-01

    Three years after Katrina,the United States isdetermined not to repeatits mistakes This year has seen an unusually activeand deadly hurricane season, asstorms line up in the Atlantic Oceanto pummel the Caribbean and UnitedStates coastline.

  2. Recent warming at Summit, Greenland: Global context and implications

    Science.gov (United States)

    McGrath, Daniel; Colgan, William; Bayou, Nicolas; Muto, Atsuhiro; Steffen, Konrad

    2013-05-01

    at Summit, Greenland suggest that the annual mean near-surface air temperature increased at 0.09 ± 0.01°C/a over the 1982-2011 climatology period. This rate of warming, six times the global average, places Summit in the 99th percentile of all globally observed warming trends over this period. The rate of warming at Summit is increasing over time. During the instrumental period (1987-2011), warming has been greatest in the winter season, although the implications of summer warming are more acute. The annual maximum elevation of the equilibrium line and dry snow line has risen at 44 and 35 m/a over the past 15 and 18 years, respectively. Extrapolation of this observed trend now suggests, with 95% confidence intervals, that the dry snow facies of the Greenland Ice Sheet will inevitably transition to percolation facies. There is a 50% probability of this transition occurring by 2025.

  3. Effects of apparent temperature on daily mortality in Lisbon and Oporto, Portugal

    Directory of Open Access Journals (Sweden)

    Casimiro Elsa

    2010-03-01

    Full Text Available Abstract Background Evidence that elevated temperatures can lead to increased mortality is well documented, with population vulnerability being location specific. However, very few studies have been conducted that assess the effects of temperature on daily mortality in urban areas in Portugal. Methods In this paper time-series analysis was used to model the relationship between mean apparent temperature and daily mortality during the warm season (April to September in the two largest urban areas in Portugal: Lisbon and Oporto. We used generalized additive Poisson regression models, adjusted for day of week and season. Results Our results show that in Lisbon, a 1°C increase in mean apparent temperature is associated with a 2.1% (95%CI: 1.6, 2.5, 2.4% (95%CI: 1.7, 3.1 and 1.7% (95%CI: 0.1, 3.4 increase in all-causes, cardiovascular, and respiratory mortality, respectively. In Oporto the increase was 1.5% (95%CI: 1.0, 1.9, 2.1% (95%CI: 1.3, 2.9 and 2.7% (95%CI: 1.2, 4.3 respectively. In both cities, this increase was greater for the group >65 years. Conclusion Even without extremes in apparent temperature, we observed an association between temperature and daily mortality in Portugal. Additional research is needed to allow for better assessment of vulnerability within populations in Portugal in order to develop more effective heat-related morbidity and mortality public health programs.

  4. Ocean acidification exerts negative effects during warming conditions in a developing Antarctic fish.

    Science.gov (United States)

    Flynn, Erin E; Bjelde, Brittany E; Miller, Nathan A; Todgham, Anne E

    2015-01-01

    Anthropogenic CO2 is rapidly causing oceans to become warmer and more acidic, challenging marine ectotherms to respond to simultaneous changes in their environment. While recent work has highlighted that marine fishes, particularly during early development, can be vulnerable to ocean acidification, we lack an understanding of how life-history strategies, ecosystems and concurrent ocean warming interplay with interspecific susceptibility. To address the effects of multiple ocean changes on cold-adapted, slowly developing fishes, we investigated the interactive effects of elevated partial pressure of carbon dioxide (pCO2) and temperature on the embryonic physiology of an Antarctic dragonfish (Gymnodraco acuticeps), with protracted embryogenesis (∼10 months). Using an integrative, experimental approach, our research examined the impacts of near-future warming [-1 (ambient) and 2°C (+3°C)] and ocean acidification [420 (ambient), 650 (moderate) and 1000 μatm pCO2 (high)] on survival, development and metabolic processes over the course of 3 weeks in early development. In the presence of increased pCO2 alone, embryonic mortality did not increase, with greatest overall survival at the highest pCO2. Furthermore, embryos were significantly more likely to be at a later developmental stage at high pCO2 by 3 weeks relative to ambient pCO2. However, in combined warming and ocean acidification scenarios, dragonfish embryos experienced a dose-dependent, synergistic decrease in survival and developed more slowly. We also found significant interactions between temperature, pCO2 and time in aerobic enzyme activity (citrate synthase). Increased temperature alone increased whole-organism metabolic rate (O2 consumption) and developmental rate and slightly decreased osmolality at the cost of increased mortality. Our findings suggest that developing dragonfish are more sensitive to ocean warming and may experience negative physiological effects of ocean acidification only in

  5. Seasonally derived components of the Canada Basin halocline

    Science.gov (United States)

    Timmermans, Mary-Louise; Marshall, John; Proshutinsky, Andrey; Scott, Jeffery

    2017-05-01

    The Arctic halocline stratification is an important barrier to the transport of deep ocean heat to the underside of sea ice. Surface water in the Chukchi Sea, warmed in summer by solar radiation, ventilates the Canada Basin halocline to create a warm layer below the mixed-layer base. The year-round persistence of this layer is shown to be consistent with the seasonal cycle of halocline ventilation. We present hydrographic observations and model results to show how Chukchi Sea density outcrops migrate seasonally as surface fluxes modify salinity and temperature. This migration is such that in winter, isopycnals bounding the warm halocline are blocked from ventilation, while the cool, relatively salty and deeper halocline layers are ventilated. In this way, the warm halocline is isolated by stratification (both vertically and laterally) each winter. Results shed light on the fate and impact to sea ice of the warm halocline under future freshening and warming of the surface Arctic Ocean.

  6. A possible relationship between Global Warming and Lightning Activity in India during the period 1998-2009

    CERN Document Server

    B., Felix Pereira; Girish, T E

    2010-01-01

    Lightning activity on a global scale has been studied season wise using satellite data for the period from 1998 to 2009. Lightning activity shows an increasing trend during the period of study which is highly correlated with atmospheric warming. A similar increasing trend of lightning activity is observed in the Indian region during the pre-monsoon season which is correlated with global lightning trends and warming trends of surface temperature in India. Key words: Global warming, lightning activity, Solar cycle changes

  7. Vertical structure of recent Arctic warming.

    Science.gov (United States)

    Graversen, Rune G; Mauritsen, Thorsten; Tjernström, Michael; Källén, Erland; Svensson, Gunilla

    2008-01-03

    Near-surface warming in the Arctic has been almost twice as large as the global average over recent decades-a phenomenon that is known as the 'Arctic amplification'. The underlying causes of this temperature amplification remain uncertain. The reduction in snow and ice cover that has occurred over recent decades may have played a role. Climate model experiments indicate that when global temperature rises, Arctic snow and ice cover retreats, causing excessive polar warming. Reduction of the snow and ice cover causes albedo changes, and increased refreezing of sea ice during the cold season and decreases in sea-ice thickness both increase heat flux from the ocean to the atmosphere. Changes in oceanic and atmospheric circulation, as well as cloud cover, have also been proposed to cause Arctic temperature amplification. Here we examine the vertical structure of temperature change in the Arctic during the late twentieth century using reanalysis data. We find evidence for temperature amplification well above the surface. Snow and ice feedbacks cannot be the main cause of the warming aloft during the greater part of the year, because these feedbacks are expected to primarily affect temperatures in the lowermost part of the atmosphere, resulting in a pattern of warming that we only observe in spring. A significant proportion of the observed temperature amplification must therefore be explained by mechanisms that induce warming above the lowermost part of the atmosphere. We regress the Arctic temperature field on the atmospheric energy transport into the Arctic and find that, in the summer half-year, a significant proportion of the vertical structure of warming can be explained by changes in this variable. We conclude that changes in atmospheric heat transport may be an important cause of the recent Arctic temperature amplification.

  8. The Impacts of Heatwaves on Mortality Differ with Different Study Periods: A Multi-City Time Series Investigation.

    Science.gov (United States)

    Wang, Xiao Yu; Guo, Yuming; FitzGerald, Gerry; Aitken, Peter; Tippett, Vivienne; Chen, Dong; Wang, Xiaoming; Tong, Shilu

    2015-01-01

    Different locations and study periods were used in the assessment of the relationships between heatwaves and mortality. However, little is known about the comparability and consistency of the previous effect estimates in the literature. This study assessed the heatwave-mortality relationship using different study periods in the three largest Australian cities (Brisbane, Melbourne and Sydney). Daily data on climatic variables and mortality for the three cities were obtained from relevant government agencies between 1988 and 2011. A consistent definition of heatwaves was used for these cities. Poisson generalised additive model was fitted to assess the impact of heatwaves on mortality. Non-accidental and circulatory mortality significantly increased during heatwaves across the three cities even with different heatwave definitions and study periods. Using the summer data resulted in the largest increase in effect estimates compared to those using the warm season or the whole year data. The findings may have implications for developing standard approaches to evaluating the heatwave-mortality relationship and advancing heat health warning systems. It also provides an impetus to methodological advance for assessing climate change-related health consequences.

  9. The Impacts of Heatwaves on Mortality Differ with Different Study Periods: A Multi-City Time Series Investigation.

    Directory of Open Access Journals (Sweden)

    Xiao Yu Wang

    Full Text Available Different locations and study periods were used in the assessment of the relationships between heatwaves and mortality. However, little is known about the comparability and consistency of the previous effect estimates in the literature. This study assessed the heatwave-mortality relationship using different study periods in the three largest Australian cities (Brisbane, Melbourne and Sydney.Daily data on climatic variables and mortality for the three cities were obtained from relevant government agencies between 1988 and 2011. A consistent definition of heatwaves was used for these cities. Poisson generalised additive model was fitted to assess the impact of heatwaves on mortality.Non-accidental and circulatory mortality significantly increased during heatwaves across the three cities even with different heatwave definitions and study periods. Using the summer data resulted in the largest increase in effect estimates compared to those using the warm season or the whole year data.The findings may have implications for developing standard approaches to evaluating the heatwave-mortality relationship and advancing heat health warning systems. It also provides an impetus to methodological advance for assessing climate change-related health consequences.

  10. How Will Climate Warming Affect Non-Native Pumpkinseed Lepomis gibbosus Populations in the U.K.?

    Science.gov (United States)

    Zięba, Grzegorz; Fox, Michael G; Copp, Gordon H

    2015-01-01

    Of the non-native fishes introduced to the U.K., the pumpkinseed is one of six species predicted to benefit from the forecasted climate warming conditions. To demonstrate the potential response of adults and their progeny to a water temperature increase, investigations of parental pumpkinseed acclimatization, reproduction and YOY over-wintering were carried out in outdoor experimental ponds under ambient and elevated water temperature regimes. No temperature effects were observed on either adult survivorship and growth, and none of the assessed reproductive activity variables (total spawning time, spawning season length, number of spawning bouts) appeared to be responsible for the large differences observed in progeny number and biomass. However, it was demonstrated in a previous study [Zięba G. et al., 2010] that adults in the heated ponds began spawning earlier than those of the ambient ponds. Ambient ponds produced 2.8× more progeny than the heated ponds, but these progeny were significantly smaller, probably due to their late hatching date, and subsequently suffered very high mortality over the first winter. Pumpkinseed in the U.K. will clearly benefit from climate warming through earlier seasonal reproduction, resulting in larger progeny going into winter, and as a result, higher over-winter survivorship would be expected relative to that which occurs under the present climatic regime.

  11. How Will Climate Warming Affect Non-Native Pumpkinseed Lepomis gibbosus Populations in the U.K.?

    Directory of Open Access Journals (Sweden)

    Grzegorz Zięba

    Full Text Available Of the non-native fishes introduced to the U.K., the pumpkinseed is one of six species predicted to benefit from the forecasted climate warming conditions. To demonstrate the potential response of adults and their progeny to a water temperature increase, investigations of parental pumpkinseed acclimatization, reproduction and YOY over-wintering were carried out in outdoor experimental ponds under ambient and elevated water temperature regimes. No temperature effects were observed on either adult survivorship and growth, and none of the assessed reproductive activity variables (total spawning time, spawning season length, number of spawning bouts appeared to be responsible for the large differences observed in progeny number and biomass. However, it was demonstrated in a previous study [Zięba G. et al., 2010] that adults in the heated ponds began spawning earlier than those of the ambient ponds. Ambient ponds produced 2.8× more progeny than the heated ponds, but these progeny were significantly smaller, probably due to their late hatching date, and subsequently suffered very high mortality over the first winter. Pumpkinseed in the U.K. will clearly benefit from climate warming through earlier seasonal reproduction, resulting in larger progeny going into winter, and as a result, higher over-winter survivorship would be expected relative to that which occurs under the present climatic regime.

  12. How Will Climate Warming Affect Non-Native Pumpkinseed Lepomis gibbosus Populations in the U.K.?

    Science.gov (United States)

    Zięba, Grzegorz; Fox, Michael G.; Copp, Gordon H.

    2015-01-01

    Of the non-native fishes introduced to the U.K., the pumpkinseed is one of six species predicted to benefit from the forecasted climate warming conditions. To demonstrate the potential response of adults and their progeny to a water temperature increase, investigations of parental pumpkinseed acclimatization, reproduction and YOY over-wintering were carried out in outdoor experimental ponds under ambient and elevated water temperature regimes. No temperature effects were observed on either adult survivorship and growth, and none of the assessed reproductive activity variables (total spawning time, spawning season length, number of spawning bouts) appeared to be responsible for the large differences observed in progeny number and biomass. However, it was demonstrated in a previous study [Zięba G. et al., 2010] that adults in the heated ponds began spawning earlier than those of the ambient ponds. Ambient ponds produced 2.8× more progeny than the heated ponds, but these progeny were significantly smaller, probably due to their late hatching date, and subsequently suffered very high mortality over the first winter. Pumpkinseed in the U.K. will clearly benefit from climate warming through earlier seasonal reproduction, resulting in larger progeny going into winter, and as a result, higher over-winter survivorship would be expected relative to that which occurs under the present climatic regime. PMID:26302021

  13. Effects of in situ climate warming on monarch caterpillar (Danaus plexippus) development.

    Science.gov (United States)

    Lemoine, Nathan P; Capdevielle, Jillian N; Parker, John D

    2015-01-01

    Climate warming will fundamentally alter basic life history strategies of many ectothermic insects. In the lab, rising temperatures increase growth rates of lepidopteran larvae but also reduce final pupal mass and increase mortality. Using in situ field warming experiments on their natural host plants, we assessed the impact of climate warming on development of monarch (Danaus plexippus) larvae. Monarchs were reared on Asclepias tuberosa grown under 'Ambient' and 'Warmed' conditions. We quantified time to pupation, final pupal mass, and survivorship. Warming significantly decreased time to pupation, such that an increase of 1 °C corresponded to a 0.5 day decrease in pupation time. In contrast, survivorship and pupal mass were not affected by warming. Our results indicate that climate warming will speed the developmental rate of monarchs, influencing their ecological and evolutionary dynamics. However, the effects of climate warming on larval development in other monarch populations and at different times of year should be investigated.

  14. Analysing Atmospheric Processes and Climatic Drivers of Tree Defoliation to Determine Forest Vulnerability to Climate Warming

    National Research Council Canada - National Science Library

    Sánchez-Salguero, Raúl; Camarero, J; Grau, José; de la Cruz, Ana; Gil, Paula; Minaya, Mayte; Fernández-Cancio, Ángel

    ...) as a proxy of forest health. Climate warming and drought are assumed to be the major drivers of tree growth and crown defoliation, particularly in seasonally dry areas such as the Mediterranean Basin...

  15. Mortality investigation

    Science.gov (United States)

    Work, Thierry M.; Franson, J. Christian; Friend, Milton; Gibbs, Samantha E.J.; Wild, Margaret A.

    2015-01-01

    Wildlife mortality events usually occur unannounced and may find management agencies unaware. These events can become highly visible and politically charged affairs, depending upon the scale or species involved. The public, media, and (or) politicians may pressure managers, field investigators, and diagnosticians to quickly identify the cause or to comment on potential causes, the significance of the event, what is being done about it, and a resolution. It may be common during such events for speculation to rage, and for conflicting theories to be advanced to explain either the environmental conditions that led to the mortality or the actual cause of death.

  16. FOUR SEASONS

    Institute of Scientific and Technical Information of China (English)

    金典; 徐吟潇

    2012-01-01

    There are four seasons in a year. When spring comes, it gets warmer and warmer. Green grass bursts out from the ground and covers the earth with green clothes. Some trees sprout bright flowers. Swallows fly high up in the sky and sing happily as if they are welcoming the spring.

  17. Experimental winter warming modifies thermal performance and primes acorn ants for warm weather.

    Science.gov (United States)

    MacLean, Heidi J; Penick, Clint A; Dunn, Robert R; Diamond, Sarah E

    2017-07-01

    The frequency of warm winter days is increasing under global climate change, but how organisms respond to warmer winters is not well understood. Most studies focus on growing season responses to warming. Locomotor performance is often highly sensitive to temperature, and can determine fitness outcomes through a variety of mechanisms including resource acquisition and predator escape. As a consequence, locomotor performance, and its impacts on fitness, may be strongly affected by winter warming in winter-active species. Here we use the acorn ant, Temnothorax curvispinosus, to explore how thermal performance (temperature-driven plasticity) in running speed is influenced by experimental winter warming of 3-5°C above ambient in a field setting. We used running speed as a measure of performance as it is a common locomotor trait that influences acquisition of nest sites and food in acorn ants. Experimental winter warming significantly altered thermal performance for running speed at high (26 and 36°C) but not low test temperatures (6 and 16°C). Although we saw little differentiation in thermal performance at cooler test temperatures, we saw a marked increase in running speed at the hotter test temperatures for ants that experienced warmer winters compared with those that experienced cooler winters. Our results provide evidence that overwintering temperatures can substantially influence organismal performance, and suggest that we cannot ignore overwintering effects when forecasting organismal responses to environmental changes in temperature. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Regional and seasonal response of a West Nile virus vector to climate change.

    Science.gov (United States)

    Morin, Cory W; Comrie, Andrew C

    2013-09-24

    Climate change will affect the abundance and seasonality of West Nile virus (WNV) vectors, altering the risk of virus transmission to humans. Using downscaled general circulation model output, we calculate a WNV vector's response to climate change across the southern United States using process-based modeling. In the eastern United States, Culex quinquefasciatus response to projected climate change displays a latitudinal and elevational gradient. Projected summer population depressions as a result of increased immature mortality and habitat drying are most severe in the south and almost absent further north; extended spring and fall survival is ubiquitous. Much of California also exhibits a bimodal pattern. Projected onset of mosquito season is delayed in the southwestern United States because of extremely dry and hot spring and summers; however, increased temperature and late summer and fall rains extend the mosquito season. These results are unique in being a broad-scale calculation of the projected impacts of climate change on a WNV vector. The results show that, despite projected widespread future warming, the future seasonal response of C. quinquefasciatus populations across the southern United States will not be homogeneous, and will depend on specific combinations of local and regional conditions.

  19. Reality of Global Warming

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Global warming is today heard in the international arena as frequently and with the same brooding concern as terrorism, nuclear weapons and the Iraq war. Zou Ji, Vice Dean of the School of Environment, Renmin University of China in Beijing, has been a me

  20. Seasonal Climate Extremes : Mechanism, Predictability and Responses to Global Warming

    NARCIS (Netherlands)

    Shongwe, M.E.

    2010-01-01

    Climate extremes are rarely occurring natural phenomena in the climate system. They often pose one of the greatest environmental threats to human and natural systems. Statistical methods are commonly used to investigate characteristics of climate extremes. The fitted statistical properties are often

  1. Warm season performance of horizontal subsurface flow constructed ...

    African Journals Online (AJOL)

    user

    2013-06-14

    Jun 14, 2013 ... 54 cm height) batch fed daily with water from a nearby urban stream ... of water quality of urban and peri-urban water resources. .... nearby monitored by The National Center of Cotton Research ... Respectively, in the first and second cultivation ... reflecting both respiration and organic matter degradation.

  2. Performances of some warm-season turfgrasses under ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-09-15

    Sep 15, 2009 ... The experimental design was a randomised complete blocks with four replications. Results .... youngest, fully expanded leaf blades of 20 samples. Ground ... (1.5 m x 0.50 m) and were dried in a forced-air oven at 70ºC for 48.

  3. Rationale for implementation of warm cardiac surgery in pediatrics

    Directory of Open Access Journals (Sweden)

    Yves eDurandy

    2016-05-01

    Full Text Available Cardiac surgery was developed thanks to the introduction of hypothermia and cardiopulmonary bypass in the early 1950s. The deep hypothermia protective effect has been essential to circulatory arrest complex cases repair. During the early times of open-heart surgery, a major concern was to decrease mortality and to improve short-term outcomes. Both mortality and morbidity dramatically decreased over a few decades. As a consequence, the drawbacks of deep hypothermia, with or without circulatory arrest, became more and more apparent. The limitation of hypothermia was particularly evident for the brain and regional perfusion was introduced as a response to this problem. Despite a gain in popularity, the results of regional perfusion were not fully convincing.In the 1990s, warm surgery was introduced in adults and proved to be safe and reliable. This option eliminates the deleterious effect of ischemia reperfusion injuries through a continuous, systemic coronary perfusion with warm oxygenated blood. Intermittent warm blood cardioplegia was introduced later, with impressive results.We were convinced by the easiness, safety and efficiency of warm surgery and shifted to warm pediatric surgery in a two-step program.This article outlines the limitations of hypothermic protection and the basic reasons that led us to implement pediatric warm surgery. After tens of thousands of cases performed across several centers, this reproducible technique proved a valuable alternative to hypothermic surgery.

  4. FVS and global Warming: A prospectus for future development

    Science.gov (United States)

    Nicholas L. Crookston; Gerald E. Rehfeldt; Dennis E. Ferguson; Marcus Warwell

    2008-01-01

    Climate change-global warming and changes in precipitation-will cause changes in tree growth rates, mortality rates, the distribution of tree species, competition, and species interactions. An implicit assumption in FVS is that site quality will remain the same as it was during the time period observations used to calibrate the component models were made and that the...

  5. Mortality Implications of Mortality Plateaus

    DEFF Research Database (Denmark)

    Missov, T. I.; Vaupel, J. W.

    2015-01-01

    This article aims to describe in a unified framework all plateau-generating random effects models in terms of (i) plausible distributions for the hazard (baseline mortality) and the random effect (unobserved heterogeneity, frailty) as well as (ii) the impact of frailty on the baseline hazard. Mor...

  6. Warm Springs pupfish recovery plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document gives a history of pupfish and focuses on the warm springs pupfish. The warm springs pupfish is endangered, and this is a plan to help recover the...

  7. Seasonal regulation of herbivory and nutrient effects on macroalgal recruitment and succession in a Florida coral reef

    Directory of Open Access Journals (Sweden)

    Alain Duran

    2016-11-01

    Full Text Available Herbivory and nutrient enrichment are drivers of benthic dynamics of coral reef macroalgae; however, their impact may vary seasonally. In this study we evaluated the effects of herbivore pressure, nutrient availability and potential propagule supply on seasonal recruitment and succession of macroalgal communities on a Florida coral reef. Recruitment tiles, replaced every three months, and succession tiles, kept in the field for nine months, were established in an ongoing factorial nutrient enrichment-herbivore exclusion experiment. The ongoing experiment had already created very different algal communities across the different herbivory and nutrient treatments. We tracked algal recruitment, species richness, and species abundance through time. Our results show seasonal variation in the effect of herbivory and nutrient availability on recruitment of coral reef macroalgae. In the spring, when there was higher macroalgal species richness and abundance of recruits, herbivory appeared to have more control on macroalgal community structure than did nutrients. In contrast, there was no effect of either herbivory or nutrient enrichment on macroalgal communities on recruitment tiles in cooler seasons. The abundance of recruits on tiles was positively correlated with the abundance of algal in the ongoing, established experiment, suggesting that propagule abundance is likely a strong influence on algal recruitment and early succession. Results of the present study suggest that abundant herbivorous fishes control recruitment and succession of macroalgae, particularly in the warm season when macroalgal growth is higher. However, herbivory appears less impactful on algal recruitment and community dynamics in cooler seasons. Ultimately, our data suggest that the timing of coral mortality (e.g., summer vs. winter mortality and freeing of benthic space may strongly influence the dynamics of algae that colonize open space.

  8. Exploring the association between heat and mortality in Switzerland between 1995 and 2013.

    Science.gov (United States)

    Ragettli, Martina S; Vicedo-Cabrera, Ana M; Schindler, Christian; Röösli, Martin

    2017-10-01

    Designing effective public health strategies to prevent adverse health effect of hot weather is crucial in the context of global warming. In Switzerland, the 2003 heat have caused an estimated 7% increase in all-cause mortality. As a consequence, the Swiss Federal Office of Public Health developed an information campaign to raise public awareness on heat threats. For a better understanding on how hot weather affects daily mortality in Switzerland, we assessed the effect of heat on daily mortality in eight Swiss cities and population subgroups from 1995 to 2013 using different temperature metrics (daily mean (Tmean), maximum (Tmax), minimum (Tmin) and maximum apparent temperature (Tappmax)), and aimed to evaluate variations of the heat effect after 2003 (1995-2002 versus 2004-2013). We applied conditional quasi-Poisson regression models with non-linear distributed lag functions to estimate temperature-mortality associations over all cities (1995-2013) and separately for two time periods (1995-2002, 2004-2013). Relative risks (RR) of daily mortality were estimated for increases in temperature from the median to the 98th percentile of the warm season temperature distribution. Over the whole time period, significant temperature-mortality relationships were found for all temperature indicators (RR (95% confidence interval): Tappmax: 1.12 (1.05; 1.18); Tmax: 1.15 (1.08-1.22); Tmean: 1.16 (1.09-1.23); Tmin 1.23 (1.15-1.32)). Mortality risks were higher at the beginning of the summer, especially for Tmin. In the more recent time period, we observed a non-significant reduction in the effect of high temperatures on mortality, with the age group > 74 years remaining the population at highest risk. High temperatures continue to be a considerable risk factor for human health in Switzerland after 2003. More effective public health measures targeting the elderly should be promoted with increased attention to the first heat events in summer and considering both high day-time and

  9. Warming and drought reduce temperature sensitivity of nitrogen transformations.

    Science.gov (United States)

    Novem Auyeung, Dolaporn S; Suseela, Vidya; Dukes, Jeffrey S

    2013-02-01

    Shifts in nitrogen (N) mineralization and nitrification rates due to global changes can influence nutrient availability, which can affect terrestrial productivity and climate change feedbacks. While many single-factor studies have examined the effects of environmental changes on N mineralization and nitrification, few have examined these effects in a multifactor context or recorded how these effects vary seasonally. In an old-field ecosystem in Massachusetts, USA, we investigated the combined effects of four levels of warming (up to 4 °C) and three levels of precipitation (drought, ambient, and wet) on net N mineralization, net nitrification, and potential nitrification. We also examined the treatment effects on the temperature sensitivity of net N mineralization and net nitrification and on the ratio of C mineralization to net N mineralization. During winter, freeze-thaw events, snow depth, and soil freezing depth explained little of the variation in net nitrification and N mineralization rates among treatments. During two years of treatments, warming and altered precipitation rarely influenced the rates of N cycling, and there was no evidence of a seasonal pattern in the responses. In contrast, warming and drought dramatically decreased the apparent Q10 of net N mineralization and net nitrification, and the warming-induced decrease in apparent Q10 was more pronounced in ambient and wet treatments than the drought treatment. The ratio of C mineralization to net N mineralization varied over time and was sensitive to the interactive effects of warming and altered precipitation. Although many studies have found that warming tends to accelerate N cycling, our results suggest that warming can have little to no effect on N cycling in some ecosystems. Thus, ecosystem models that assume that warming will consistently increase N mineralization rates and inputs of plant-available N may overestimate the increase in terrestrial productivity and the magnitude of an important

  10. Extreme warm temperatures alter forest phenology and productivity in Europe.

    Science.gov (United States)

    Crabbe, Richard A; Dash, Jadu; Rodriguez-Galiano, Victor F; Janous, Dalibor; Pavelka, Marian; Marek, Michal V

    2016-09-01

    Recent climate warming has shifted the timing of spring and autumn vegetation phenological events in the temperate and boreal forest ecosystems of Europe. In many areas spring phenological events start earlier and autumn events switch between earlier and later onset. Consequently, the length of growing season in mid and high latitudes of European forest is extended. However, the lagged effects (i.e. the impact of a warm spring or autumn on the subsequent phenological events) on vegetation phenology and productivity are less explored. In this study, we have (1) characterised extreme warm spring and extreme warm autumn events in Europe during 2003-2011, and (2) investigated if direct impact on forest phenology and productivity due to a specific warm event translated to a lagged effect in subsequent phenological events. We found that warmer events in spring occurred extensively in high latitude Europe producing a significant earlier onset of greening (OG) in broadleaf deciduous forest (BLDF) and mixed forest (MF). However, this earlier OG did not show any significant lagged effects on autumnal senescence. Needleleaf evergreen forest (NLEF), BLDF and MF showed a significantly delayed end of senescence (EOS) as a result of extreme warm autumn events; and in the following year's spring phenological events, OG started significantly earlier. Extreme warm spring events directly led to significant (p=0.0189) increases in the productivity of BLDF. In order to have a complete understanding of ecosystems response to warm temperature during key phenological events, particularly autumn events, the lagged effect on the next growing season should be considered.

  11. Warm Little Inflaton.

    Science.gov (United States)

    Bastero-Gil, Mar; Berera, Arjun; Ramos, Rudnei O; Rosa, João G

    2016-10-07

    We show that inflation can naturally occur at a finite temperature T>H that is sustained by dissipative effects, when the inflaton field corresponds to a pseudo Nambu-Goldstone boson of a broken gauge symmetry. Similar to the Little Higgs scenarios for electroweak symmetry breaking, the flatness of the inflaton potential is protected against both quadratic divergences and the leading thermal corrections. We show that, nevertheless, nonlocal dissipative effects are naturally present and are able to sustain a nearly thermal bath of light particles despite the accelerated expansion of the Universe. As an example, we discuss the dynamics of chaotic warm inflation with a quartic potential and show that the associated observational predictions are in very good agreement with the latest Planck results. This model constitutes the first realization of warm inflation requiring only a small number of fields; in particular, the inflaton is directly coupled to just two light fields.

  12. Warm Little Inflaton

    CERN Document Server

    Bastero-Gil, Mar; Ramos, Rudnei O; Rosa, Joao G

    2016-01-01

    We show that inflation can naturally occur at a finite temperature T>H that is sustained by dissipative effects, when the inflaton field corresponds to a pseudo-Nambu Goldstone boson of a broken gauge symmetry. Similarly to "Little Higgs" scenarios for electroweak symmetry breaking, the flatness of the inflaton potential is protected against both quadratic divergences and the leading thermal corrections. We show that, nevertheless, non-local dissipative effects are naturally present and are able to sustain a nearly-thermal bath of light particles despite the accelerated expansion of the Universe. As an example, we discuss the dynamics of chaotic warm inflation with a quartic potential and show that the associated observational predictions are in very good agreement with the latest Planck results. This model constitutes the first realization of warm inflation where the inflaton is directly coupled to only two light fields.

  13. The Arctic Ocean's seasonal cycle must change

    Science.gov (United States)

    Carton, James; Ding, Yanni

    2015-04-01

    This paper discusses anticipated changes to the seasonal cycle of the Arctic Ocean along with Arctic surface climate due to the reduction of seasonal sea ice cover expected in the 21st century. Net surface shortwave radiation is a function of surface reflectivity and atmospheric transparency as well as solar declination. Recent observational studies and modeling results presented here strongly suggest that this excess heat in the summer is currently being stored locally in the form of ocean warming and sea ice melt. This heat is lost in winter/spring through surface loss through longwave and turbulent processes causing ocean cooling and the refreezing of sea ice. A striking feature of Arctic climate during the 20th century has been the enhanced warming experienced during winter in response to increases in anthropogenic greenhouse gasses. The amplitude of the seasonal cycle of surface air temperature is declining by gradually warming winter temperatures relative to summer temperatures. Bintanja and van der Linden (2013) show this process will eventually cause the 30C seasonal change in air temperature to reduce by half as seasonal sea ice disappears. The much weaker seasonal cycle of ocean temperature, which is controlled by the need to store excess surface heat seasonally, is also going to be affected by the loss of sea ice but in quite different ways. In particular the ocean will need to compensate for the loss of seasonal heat storage by the ice pack. This study examines consequences for the Arctic Ocean stratification and circulation in a suite of CMIP5 models under future emissions scenarios relative to their performance during the 20th century and to explore a range of model ocean responses to declining sea ice cover on the Arctic Ocean.

  14. Phytoplankton response to winter warming modified by large-bodied zooplankton: an experimental microcosm study

    Directory of Open Access Journals (Sweden)

    Hu He

    2015-03-01

    Full Text Available While several field investigations have demonstrated significant effects of cool season (winter or spring warming on phytoplankton development, the role played by large-bodied zooplankton grazers for the responses of phytoplankton to winter warming is ambiguous. We conducted an outdoor experiment to compare the effect of winter warming (heating by 3°C in combination with presence and absence of Daphnia grazing (D. similis on phytoplankton standing crops and community structure under eutrophic conditions. When Daphnia were absent, warming was associated with significant increases in phytoplankton biomass and cyanobacterial dominance. In contrast, when Daphnia were present, warming effects on phytoplankton dynamics were offset by warming-enhanced grazing, resulting in no significant change in biomass or taxonomic dominance. These results emphasize that large-bodied zooplankton like Daphnia spp. may play an important role in modulating the interactions between climate warming and phytoplankton dynamics in nutrient rich lake ecosystems.

  15. Military Implications of Global Warming.

    Science.gov (United States)

    2007-11-02

    U.S. environmental issues also have important global implications. This paper analyzes current U.S. Policy as it pertains to global warming and climate...for military involvement to reduce global warming . Global warming and other environmental issues are important to the U.S. military. As the United

  16. Robust cloud feedback over tropical land in a warming climate

    Science.gov (United States)

    Kamae, Youichi; Ogura, Tomoo; Watanabe, Masahiro; Xie, Shang-Ping; Ueda, Hiroaki

    2016-03-01

    Cloud-related radiative perturbations over land in a warming climate are of importance for human health, ecosystem, agriculture, and industry via solar radiation availability and local warming amplification. However, robustness and physical mechanisms responsible for the land cloud feedback were not examined sufficiently because of the limited contribution to uncertainty in global climate sensitivity. Here we show that cloud feedback in general circulation models over tropical land is robust, positive, and is relevant to atmospheric circulation change and thermodynamic constraint associated with water vapor availability. In a warming climate, spatial variations in tropospheric warming associated with climatological circulation pattern result in a general weakening of tropical circulation and a dynamic reduction of land cloud during summer monsoon season. Limited increase in availability of water vapor also reduces the land cloud. The reduction of land cloud depends on global-scale oceanic warming and is not sensitive to regional warming patterns. The robust positive feedback can contribute to the warming amplification and drying over tropical land in the future.

  17. Global Warming And Meltwater

    Science.gov (United States)

    Bratu, S.

    2012-04-01

    In order to find new approaches and new ideas for my students to appreciate the importance of science in their daily life, I proposed a theme for them to debate. They had to search for global warming information and illustrations in the media, and discuss the articles they found in the classroom. This task inspired them to search for new information about this important and timely theme in science. I informed my students that all the best information about global warming and meltwater they found would be used in a poster that would help us to update the knowledge base of the Physics laboratory. I guided them to choose the most eloquent images and significant information. Searching and working to create this poster, the students arrived to better appreciate the importance of science in their daily life and to critically evaluate scientific information transmitted via the media. In the poster we created, one can find images, photos and diagrams and some interesting information: Global warming refers to the rising average temperature of the Earth's atmosphere and oceans and its projected evolution. In the last 100 years, the Earth's average surface temperature increased by about 0.8 °C with about two thirds of the increase occurring over just the last three decades. Warming of the climate system is unequivocal, and scientists are more than 90% certain most of it is caused by increasing concentrations of greenhouse gases produced by human activities such as deforestation and burning fossil fuel. They indicate that during the 21st century the global surface temperature is likely to rise a further 1.1 to 2.9 °C for the lowest emissions scenario and 2.4 to 6.4 °C for the highest predictions. An increase in global temperature will cause sea levels to rise and will change the amount and pattern of precipitation, and potentially result in expansion of subtropical deserts. Warming is expected to be strongest in the Arctic and would be associated with continuing decrease of

  18. Global warming and allergy in Asia Minor.

    Science.gov (United States)

    Bajin, Munir Demir; Cingi, Cemal; Oghan, Fatih; Gurbuz, Melek Kezban

    2013-01-01

    The earth is warming, and it is warming quickly. Epidemiological studies have demonstrated that global warming is correlated with the frequency of pollen-induced respiratory allergy and allergic diseases. There is a body of evidence suggesting that the prevalence of allergic diseases induced by pollens is increasing in developed countries, a trend that is also evident in the Mediterranean area. Because of its mild winters and sunny days with dry summers, the Mediterranean area is different from the areas of central and northern Europe. Classical examples of allergenic pollen-producing plants of the Mediterranean climate include Parietaria, Olea and Cupressaceae. Asia Minor is a Mediterranean region that connects Asia and Europe, and it includes considerable coastal areas. Gramineae pollens are the major cause of seasonal allergic rhinitis in Asia Minor, affecting 1.3-6.4 % of the population, in accordance with other European regions. This article emphasizes the importance of global climate change and anticipated increases in the prevalence and severity of allergic disease in Asia Minor, mediated through worsening air pollution and altered local and regional pollen production, from an otolaryngologic perspective.

  19. Effects of elevated CO2, warming and drought episodes on plant carbon uptake in a temperate heath ecosystem are controlled by soil water status

    DEFF Research Database (Denmark)

    Albert, Kristian Rost; Ro-Poulsen, H.; Mikkelsen, Teis Nørgaard;

    2011-01-01

    season, whereas warming only stimulated photosynthesis early in the year. At the beginning and end of the growing season, a T × CO2 interaction synergistically stimulated plant carbon uptake in the combination of warming and elevated CO2. At peak drought, the D × CO2 interaction antagonistically down...

  20. Spatio-temporal analysis of warming in Bangladesh using recent observed temperature data and GIS

    Science.gov (United States)

    Rahman, Md. Rejaur; Lateh, Habibah

    2016-05-01

    This study focused on the annual and seasonal warming at local scale by analysing the trends, anomalies, change points and shifting of isotherm in temperature from 34 meteorological stations distributed over Bangladesh, spanning 40 years from the year 1971-2010. For trends, a linear regression using least square model was applied. Anomalies were calculated as a difference between the reference (1971-2000 mean) and actual occurrence value. Inverse distance weighted interpolation and GIS techniques were used to find out the spatial pattern of warming. Besides, the sequential version of the Mann-Kendall test was applied to detect the changing point of warming. Direction of shifting of warming was detected by the decadal distribution pattern of specific isotherms which were generated using GIS. The result reveals that the climate of Bangladesh undergone a significant warming during the period 1971-2010, 0.020 °C per year (for annual mean) and the maximum temperature warmed more than the minimum temperature (0.022 vs. 0.018 °C per year). On a seasonal basis, hot summer, humid summer and dry winter also show significant warming, 0.022, 0.026 and 0.011 °C per year, respectively. The warming of maximum temperature (0.032 °C per year) in humid summer was greater than other seasons, contributed more on annual warming. Spatial patterns indicate that geographically the warming varied significantly and some places warming exit 2.0 °C and reached up to 3.2 °C. The north western, north eastern, southern and south eastern parts of the country are more susceptible to rising temperature. In 2010, mean annual temperature was 0.84 °C warmer than the base period (1971-2000) mean. The significant warmest period was spread across the year 1995-2010, with 2010 being the warmest year. Statistically significant warming was began in early 1990's and the years 1990, 1994 and 1997 identified as important abrupt change points of warming. Moreover, a remarkably northward and north

  1. Herbivores modify the carbon cycle in a warming arctic

    Science.gov (United States)

    Cahoon, S. M.; Sullivan, P.; Welker, J. M.; Post, E.

    2009-12-01

    Typically, our studies of arctic terrestrial ecosystem responses to changes in climate focus on abiotic drivers (i.e. warming or added rain or added snow) and subsequent biogeochemical cycles and plant physiological performance. However, many arctic systems, such as those in western Greenland, are home ranges for large herbivores such as muskoxen and caribou. In order to fully understand how tundra landscapes in Greenland will respond to change, experiments are needed that allow us to quantify whether abiotic (climate warming) and or biotic (presence or absence of herbivores) drivers or their combinations regulate ecosystem function and structure. Here we present the results of two consecutive field seasons in western Greenland in which we quantified the interactive effects of local herbivore foraging and simulated climate warming on ecosystem C and N cycling and leaf level physiology. Large exclosure fences were erected in 2002, and ITEX passive warming chambers were established in 2003 within and adjacent to the fences. We performed weekly CO2 flux measurements during the 2008 and 2009 growing seasons which we normalized to a common irradiance by generating light-response curves at all plots (n=9). Although we observed interannual variability in soil moisture and average daily air temperature, browsing by herbivores was a key factor in the seasonal carbon dynamics. By physically removing leaves and upper stems, caribou and muskoxen altered the community composition, reduced leaf area and in turn decreased gross ecosystem photosynthesis (GEP), regardless of the warming treatment. Neither herbivory nor warming significantly affected ecosystem respiration rates. Thus the reduction in net ecosystem exchange (NEE) was primarily driven by reductions in GEP associated with leaf area removal by grazers. Our results indicate that the biotic influence from large herbivores can significantly influence carbon-derived climatic feedbacks and can no longer be overlooked in

  2. A decision support service for temperature-related mortality in Europe

    Science.gov (United States)

    Lowe, Rachel; Ballester, Joan; Robine, Jean-Marie; Herrmann, François R.; Jupp, Tim E.; Stephenson, David B.; Creswick, James; Rodó, Xavier

    2014-05-01

    Users of climate information often require probabilistic information on which to base their decisions. However, communicating information contained within a probabilistic forecast presents a challenge. In this paper we demonstrate a novel visualisation technique to display ternary probabilistic forecast maps of climate-related mortality across Europe. In this method, ternary probabilistic forecasts, which assign probabilities to a set of three outcomes (e.g. low, medium, and high risk), are considered as a point in a triangle of barycentric coordinates. This allows a unique colour to be assigned to each forecast from a continuum of colours defined on the triangle. Colour saturation increases with information gain relative to the reference forecast (i.e. the long term average). This provides additional information to decision makers compared with conventional methods used in seasonal climate forecasting, where one colour is used to represent one forecast category on a forecast map (e.g. red = 'dry'). Temperature and humidity are related to human mortality via location-specific transfer functions, calculated using historical data. Daily mortality data at the NUTS2 level for 16 countries in Europe were obtained from 1998-2005. Transfer functions were calculated for 54 aggregations in Europe, defined using criteria related to population and climatological similarities. A statistical model is fit to cold and warm tails to estimate future mortality using forecast temperatures, in a Bayesian probabilistic framework. Using predefined categories of temperature-related mortality risk, probabilistic forecast maps of human mortality are presented at seasonal time scales. We demonstrate the information gained from using this technique compared to more traditional methods to display ternary probabilistic forecasts. This approach allows decision makers to identify areas where the model predicts with certainty area-specific heat waves or cold snaps, in order to effectively target

  3. Mortal assets

    Energy Technology Data Exchange (ETDEWEB)

    Howe, Geoffrey R.; Zablotska, Lydia B.; Fix, John J.; Egel, John N.; Buchanan, Jeffrey A.

    2005-11-01

    Workers employed in 15 utilities that generate nuclear power in the United States have been followed for up to 18 years between 1979 and 1997. Their cumulative dose from whole-body ionizing radiation has been determined from the dose records maintained by the facilities themselves and the REIRS and REMS systems maintained by the Nuclear Regulatory Commission and the Department of Energy, respectively. Mortality in the cohort from a number of causes has been analyzed with respect to individual radiation doses. The cohort displays a very substantial healthy worker effect, i.e. considerably lower cancer and noncancer mortality than the general population. Based on 26 and 368 deaths, respectively, positive though statistically nonsignificant associations were seen for mortality from leukemia (excluding chronic lymphocytic leukemia) and all solid cancers combined, with excess relative risks per sievert of 5.67 (95% confidence interval (CI) -2.56, 30.4) and 0.596 (95% CI -2.01, 4.64), respectively. These estimates are very similar to those from the atomic bomb survivors study, though the wide confidence intervals are also consistent with lower or higher risk estimates. A strong positive and statistically significant association between radiation dose and deaths from arteriosclerotic heart disease including coronary heart disease was also observed in the cohort, with an ERR of 8.78 (95% CI 2.10, 20.0). Whle associations with heart disease have been reported in some other occupational studies, the magnitude of the present association is not consistent with them and therefore needs cautious interpretation and merits further attention. At present, the relatively small number of deaths and the young age of the cohort (mean age at end of follow-up is 45 years) limit the power of the study, but further follow-up is 45 years) limit the power of the study, but further follow-up and the inclusion of the present data in an ongoing IARC combined analysis of nuclear workers from 15

  4. Greenhouse Warming Research

    DEFF Research Database (Denmark)

    Sørensen, Bent Erik

    2016-01-01

    The changing greenhouse effect caused by natural and anthropogenic causes is explained and efforts to model the behavior of the near-surface constituents of the Earth's land, ocean and atmosphere are discussed. Emissions of various substances and other aspects of human activity influence the gree......The changing greenhouse effect caused by natural and anthropogenic causes is explained and efforts to model the behavior of the near-surface constituents of the Earth's land, ocean and atmosphere are discussed. Emissions of various substances and other aspects of human activity influence...... the greenhouse warming, and the impacts of the warming may again impact the wellbeing of human societies. Thus physical modeling of the near-surface ocean-soil-atmosphere system cannot be carried out without an idea of the development of human activities, which is done by scenario analysis. The interactive...... nature of the natural and the human system calls for an extremely complex analysis, in order to predict the outcome of various proposed changes in human behavior. This includes halting activities that most influence the climate and finding workable alternatives to these activities, or adapting to climate...

  5. Experimental warming effects on the microbial community of a temperate mountain forest soil.

    Science.gov (United States)

    Schindlbacher, A; Rodler, A; Kuffner, M; Kitzler, B; Sessitsch, A; Zechmeister-Boltenstern, S

    2011-07-01

    Soil microbial communities mediate the decomposition of soil organic matter (SOM). The amount of carbon (C) that is respired leaves the soil as CO(2) (soil respiration) and causes one of the greatest fluxes in the global carbon cycle. How soil microbial communities will respond to global warming, however, is not well understood. To elucidate the effect of warming on the microbial community we analyzed soil from the soil warming experiment Achenkirch, Austria. Soil of a mature spruce forest was warmed by 4 °C during snow-free seasons since 2004. Repeated soil sampling from control and warmed plots took place from 2008 until 2010. We monitored microbial biomass C and nitrogen (N). Microbial community composition was assessed by phospholipid fatty acid analysis (PLFA) and by quantitative real time polymerase chain reaction (qPCR) of ribosomal RNA genes. Microbial metabolic activity was estimated by soil respiration to biomass ratios and RNA to DNA ratios. Soil warming did not affect microbial biomass, nor did warming affect the abundances of most microbial groups. Warming significantly enhanced microbial metabolic activity in terms of soil respiration per amount of microbial biomass C. Microbial stress biomarkers were elevated in warmed plots. In summary, the 4 °C increase in soil temperature during the snow-free season had no influence on microbial community composition and biomass but strongly increased microbial metabolic activity and hence reduced carbon use efficiency.

  6. C4 grasses prosper as carbon dioxide eliminates desiccation in warmed semi-arid grassland.

    Science.gov (United States)

    Morgan, Jack A; LeCain, Daniel R; Pendall, Elise; Blumenthal, Dana M; Kimball, Bruce A; Carrillo, Yolima; Williams, David G; Heisler-White, Jana; Dijkstra, Feike A; West, Mark

    2011-08-03

    Global warming is predicted to induce desiccation in many world regions through increases in evaporative demand. Rising CO(2) may counter that trend by improving plant water-use efficiency. However, it is not clear how important this CO(2)-enhanced water use efficiency might be in offsetting warming-induced desiccation because higher CO(2) also leads to higher plant biomass, and therefore greater transpirational surface. Furthermore, although warming is predicted to favour warm-season, C(4) grasses, rising CO(2) should favour C(3), or cool-season plants. Here we show in a semi-arid grassland that elevated CO(2) can completely reverse the desiccating effects of moderate warming. Although enrichment of air to 600 p.p.m.v. CO(2) increased soil water content (SWC), 1.5/3.0 °C day/night warming resulted in desiccation, such that combined CO(2) enrichment and warming had no effect on SWC relative to control plots. As predicted, elevated CO(2) favoured C(3) grasses and enhanced stand productivity, whereas warming favoured C(4) grasses. Combined warming and CO(2) enrichment stimulated above-ground growth of C(4) grasses in 2 of 3 years when soil moisture most limited plant productivity. The results indicate that in a warmer, CO(2)-enriched world, both SWC and productivity in semi-arid grasslands may be higher than previously expected.

  7. Seasonal evolution of faecal egg output by gastrointestinal worms in goats on communal farms in eastern Namibia

    Directory of Open Access Journals (Sweden)

    F.F. Kumba

    2003-11-01

    Full Text Available As a more detailed continuation of a previous study, faecal samples for worm egg counts were collected per rectum from ten marked adult animals in selected flocks of goats, in each of six villages evenly spread out in the communal farming district of Okakarara in eastern Namibia. The study was conducted on a monthly basis from August 1999 to July 2000. Average faecal worm egg counts (FECs were highest during the warm-wet season, much lower during the cold-dry months and moderate during the hot-dry season. Least square means of FECs were 2 140, 430 and 653 per gram of faeces for the three seasons, respectively. Seasonal variation in egg counts was significant (P < 0.0001. Gastrointestinal strongyles, and to a lesser extent Strongyloides species, were the predominant parasite groups identified in goats. Kidding rates peaked in the cold-dry season and mortality rates in the hot-dry season. Results of this study suggest that gastrointestinal parasitism may be a problem that accentuates the effect of poor nutrition on small ruminants during the season of food shortages in the east of Namibia and that the use of FECs per se to assess the severity of gastrointestinal parasitic infection in goats followed by chemoprophylactic strategic and / or tactical treatment, may not be the best approach to addressing the worm problem under resource-poor conditions. The use of the FAMACHA(c system that identifies severely affected animals for treatment is technically a better option for communal farmers.

  8. Incorporating Temperature-driven Seasonal Variation in Survival, Growth, and Reproduction Models for Small Fish

    Science.gov (United States)

    Seasonal variation in survival and reproduction can be a large source of prediction uncertainty in models used for conservation and management. A seasonally varying matrix population model is developed that incorporates temperature-driven differences in mortality and reproduction...

  9. Seasonality of suicide deaths in Serbia, 1990-2012

    Directory of Open Access Journals (Sweden)

    Penev Goran

    2014-01-01

    Full Text Available Background: In the period from 1990 to 2012, there were 32,855 suicides registered in Serbia, i.e. an average of 1428 deaths per year (18.9 per 100.000 inhabitants. The suicides were the most frequent in the early 1990s, less frequent during the 2000s, and least frequent in the last three years of the observed period (2010-2012 - an average of 1237 suicides per year. Objective: The goal of this paper is to evaluate the seasonal variations of suicides in Serbia in the period of 1990-2012, their changes, as well as the accordance with findings from other countries. Method: In the paper are used "classical" statistical methods of evaluating cyclical variations (χ2-test, Edwards' test as well as some frequently used newer methods (e.g. the peak-low ratio. It also introduces a new indicator of the intensity of monthly variations in suicides (the magnitude of trimester variations of /12/ moving consecutive months index - the MtMV index. Seasonality of suicides is also observed by sex. Results: The results of the research of seasonality confirm that certain cyclical variations in mortality due to suicide are also present in Serbia. Observed by season, suicides are most frequent in spring and summer and less in winter. The cyclical nature was also clearly confirmed by month. Suicides are most frequent in "warm" months (April-August and far less frequent in "cold" months (December-February. By month, suicides are most frequent in May, while the maximal average number of suicides per day was calculated for June (21 % higher than the average for 1990-2012. December is singled out as the month with the lowest number as well as lowest daily average of suicides (25 % lower than the average. Conclusion: The cyclical nature of suicides is clearly notable during the entire observed period and no significant fluctuations or decrease in the intensity of the variation were observed. Regardless of the method of analysis, the resulting conclusions are identical

  10. Avoided heat-related mortality through climate adaptation strategies in three US cities.

    Science.gov (United States)

    Stone, Brian; Vargo, Jason; Liu, Peng; Habeeb, Dana; DeLucia, Anthony; Trail, Marcus; Hu, Yongtao; Russell, Armistead

    2014-01-01

    Heat-related mortality in US cities is expected to more than double by the mid-to-late 21st century. Rising heat exposure in cities is projected to result from: 1) climate forcings from changing global atmospheric composition; and 2) local land surface characteristics responsible for the urban heat island effect. The extent to which heat management strategies designed to lessen the urban heat island effect could offset future heat-related mortality remains unexplored in the literature. Using coupled global and regional climate models with a human health effects model, we estimate changes in the number of heat-related deaths in 2050 resulting from modifications to vegetative cover and surface albedo across three climatically and demographically diverse US metropolitan areas: Atlanta, Georgia, Philadelphia, Pennsylvania, and Phoenix, Arizona. Employing separate health impact functions for average warm season and heat wave conditions in 2050, we find combinations of vegetation and albedo enhancement to offset projected increases in heat-related mortality by 40 to 99% across the three metropolitan regions. These results demonstrate the potential for extensive land surface changes in cities to provide adaptive benefits to urban populations at risk for rising heat exposure with climate change.

  11. Avoided heat-related mortality through climate adaptation strategies in three US cities.

    Directory of Open Access Journals (Sweden)

    Brian Stone

    Full Text Available Heat-related mortality in US cities is expected to more than double by the mid-to-late 21st century. Rising heat exposure in cities is projected to result from: 1 climate forcings from changing global atmospheric composition; and 2 local land surface characteristics responsible for the urban heat island effect. The extent to which heat management strategies designed to lessen the urban heat island effect could offset future heat-related mortality remains unexplored in the literature. Using coupled global and regional climate models with a human health effects model, we estimate changes in the number of heat-related deaths in 2050 resulting from modifications to vegetative cover and surface albedo across three climatically and demographically diverse US metropolitan areas: Atlanta, Georgia, Philadelphia, Pennsylvania, and Phoenix, Arizona. Employing separate health impact functions for average warm season and heat wave conditions in 2050, we find combinations of vegetation and albedo enhancement to offset projected increases in heat-related mortality by 40 to 99% across the three metropolitan regions. These results demonstrate the potential for extensive land surface changes in cities to provide adaptive benefits to urban populations at risk for rising heat exposure with climate change.

  12. A congeneric comparison shows that experimental warming enhances the growth of invasive Eupatorium adenophorum.

    Directory of Open Access Journals (Sweden)

    Wei-Ming He

    Full Text Available Rising air temperatures may change the risks of invasive plants; however, little is known about how different warming timings affect the growth and stress-tolerance of invasive plants. We conducted an experiment with an invasive plant Eupatorium adenophorum and a native congener Eupatorium chinense, and contrasted their mortality, plant height, total biomass, and biomass allocation in ambient, day-, night-, and daily-warming treatments. The mortality of plants was significantly higher in E. chinense than E. adenophorum in four temperature regimes. Eupatorium adenophorum grew larger than E. chinense in the ambient climate, and this difference was amplified with warming. On the basis of the net effects of warming, daily-warming exhibited the strongest influence on E. adenophorum, followed by day-warming and night-warming. There was a positive correlation between total biomass and root weight ratio in E. adenophorum, but not in E. chinense. These findings suggest that climate warming may enhance E. adenophorum invasions through increasing its growth and stress-tolerance, and that day-, night- and daily-warming may play different roles in this facilitation.

  13. Seasonal abundance and mortality of Oebalus poecilus (Dallas (Hemiptera: Pentatomidae in a hibernation refuge Abundância sazonal e mortalidade de Oebalus poecilus (Dallas (Hemiptera: Pentatomidae no refúgio de hibernação

    Directory of Open Access Journals (Sweden)

    R. S. S. Santos

    2006-05-01

    Full Text Available Oebalus poecilus (Dallas is an important pest affecting irrigated rice in Rio Grande do Sul, Brazil. It hibernates during the coldest months of the year in refuges such as bamboo litter. This study examined O. poecilus hibernation to determine the causes of mortality during this period. The study was conducted in a 140 m² bamboo plantation located in a rice-growing area in Eldorado do Sul County (30° 02’ S and 51° 23’ W, RS. During June 2000 to April 2002, 63 samples of litter were taken in weekly or fortnightly intervals, and the number of bugs recorded in the laboratory. The arrival at the hibernation site (bamboo litter began in the first fortnight of March, and was completed in the beginning of May. O. poecilus left this refuge from middle October to the end of December. Parasitism by tachinid flies and Beauveria bassiana (Bals. Vuill. fungus were the most important mortality factors.Oebalus poecilus (Dallas é praga importante do arroz irrigado no Rio Grande do Sul, Brasil. Este inseto hiberna durante os meses mais frios em refúgios como o folhedo de bambu. Este estudo objetivou elucidar a hibernação de O. poecilus e determinar as causas de mortalidade durante este período. O estudo foi realizado em um bambuzal com cerca de 140 m², situado em área orizícola, em Eldorado do Sul (30° 02’ S e 51° 23’ W, RS. De junho/2000 à abril/2002, foram realizadas 63 amostragens de folhedo, em intervalos semanais ou quinzenais e o número de percevejos registrado em laboratório. A entrada no refúgio de hibernação (folhedo de bambu iniciou na primeira semana de março, completando-se no início de maio. O. poecilus abandonou o refúgio da metade de outubro até o final de dezembro. O parasitismo por mosca (taquinídeos e o fungo Beauveria bassiana (Bals. Vuill. foram os principais fatores de mortalidade.

  14. Warming and nitrogen fertilization effects on winter wheat yields in northern China varied between four years

    DEFF Research Database (Denmark)

    Liu, Liting; Hu, Chunsheng; Olesen, Jørgen E

    2013-01-01

    per m2. This suggests that the wheat yield loss may be related to reduction of spike number, which was affected by decreased soil water content under warming. Warming tended to give larger yield reductions at higher nitrogen fertilizer rates, and this may be related to larger water consumption......Global warming is expected to affect wheat productivity significantly, but with large regional differences depending on current climatic conditions. We conducted a study that aimed to investigate how wheat growth and development as well as yield and yield components respond to warming combined...... with nitrogen fertilization. Infrared heaters were applied above the crop and soil to provide a warming of around 2 °C at 5 cm soil depth during the whole winter wheat growing season from 2008 to 2012 at a site near Shijiazhuang in the North China Plain. Two temperature levels (warming and ambient) for winter...

  15. Competent and Warm?

    Science.gov (United States)

    Hansen, Karolina; Rakić, Tamara; Steffens, Melanie C

    2017-01-01

    Most research on ethnicity has focused on visual cues. However, accents are strong social cues that can match or contradict visual cues. We examined understudied reactions to people whose one cue suggests one ethnicity, whereas the other cue contradicts it. In an experiment conducted in Germany, job candidates spoke with an accent either congruent or incongruent with their (German or Turkish) appearance. Based on ethnolinguistic identity theory, we predicted that accents would be strong cues for categorization and evaluation. Based on expectancy violations theory we expected that incongruent targets would be evaluated more extremely than congruent targets. Both predictions were confirmed: accents strongly influenced perceptions and Turkish-looking German-accented targets were perceived as most competent of all targets (and additionally most warm). The findings show that bringing together visual and auditory information yields a more complete picture of the processes underlying impression formation.

  16. [Effects of simulated warming on soil enzyme activities in two subalpine coniferous forests in west Sichuan].

    Science.gov (United States)

    Xu, Zhen-feng; Tang, Zheng; Wan, Chuan; Xiong, Pei; Cao, Gang; Liu, Qing

    2010-11-01

    With open top chamber (OTC), this paper studied the effects of simulated warming on the activities of soil invertase, urease, catalase, polyphenol oxidase in two contrasting subalpine coniferous forests (a dragon spruce plantation and a natural conifer forest) in west Sichuan. The dynamic changes of soil temperature and soil moisture were monitored synchronously. In the whole growth season, simulated warming enhanced the daily mean temperature at soil depth 5 cm by 0.61 degrees C in the plantation, and by 0.55 degrees C in the natural forest. Conversely, the volumetric moisture at soil depth 10 cm was declined by 4.10% and 2.55%, respectively. Simulated warming also increased soil invertase, urease, catalase, and polyphenol oxidase activities. The interactive effect of warming and forest type was significant on soil urease and catalase, but not significant on soil invertase and polyphenol oxidase. The warming effect on soil catalase depended, to some extent, on season change. In all treatments, the soil enzyme activities in the natural forest were significantly higher than those in the plantation. The seasonal changes of test soil enzyme activities were highly correlated with soil temperature, but less correlated with soil moisture. This study indicated that warming could enhance soil enzyme activities, and the effect had definite correlations with forest type, enzyme category, and season change. The soil enzyme activities in the subalpine coniferous forests were mainly controlled by soil temperature rather than soil moisture.

  17. Differential responses of invasive and native plants to warming with simulated changes in diurnal temperature ranges.

    Science.gov (United States)

    Chen, Bao-Ming; Gao, Yang; Liao, Hui-Xuan; Peng, Shao-Lin

    2017-07-01

    plants, while the asymmetric summer warming treatments (DTRinc and DTRdec) decreased the biomass of the invasive but not the native plants. In addition, wintertime DTRinc did not enhance the biomass of all the plants relative to DTRsym. Our results were obtained in an unrealistic setting; the growth conditions in chambers (e.g. low light, low herbivory, no competition) are quite different from natural conditions (high light, normal herbivory and competition), which may influence the effects of warming on the seedling establishment and growth of both invasive and native plants. Nonetheless, our work highlights the importance of asymmetric warming, particularly in regards to the comparison with the effects of symmetric warming on both invasive and native plants. Conclusions regarding the effects of future warming should be made cautiously because warming with different DTRs may suggest different implications for invasion, and effects of warming may be different in different seasons.

  18. Evaluating Arctic warming mechanisms in CMIP5 models

    Science.gov (United States)

    Franzke, Christian L. E.; Lee, Sukyoung; Feldstein, Steven B.

    2016-07-01

    Arctic warming is one of the most striking signals of global warming. The Arctic is one of the fastest warming regions on Earth and constitutes, thus, a good test bed to evaluate the ability of climate models to reproduce the physics and dynamics involved in Arctic warming. Different physical and dynamical mechanisms have been proposed to explain Arctic amplification. These mechanisms include the surface albedo feedback and poleward sensible and latent heat transport processes. During the winter season when Arctic amplification is most pronounced, the first mechanism relies on an enhancement in upward surface heat flux, while the second mechanism does not. In these mechanisms, it has been proposed that downward infrared radiation (IR) plays a role to a varying degree. Here, we show that the current generation of CMIP5 climate models all reproduce Arctic warming and there are high pattern correlations—typically greater than 0.9—between the surface air temperature (SAT) trend and the downward IR trend. However, we find that there are two groups of CMIP5 models: one with small pattern correlations between the Arctic SAT trend and the surface vertical heat flux trend (Group 1), and the other with large correlations (Group 2) between the same two variables. The Group 1 models exhibit higher pattern correlations between Arctic SAT and 500 hPa geopotential height trends, than do the Group 2 models. These findings suggest that Arctic warming in Group 1 models is more closely related to changes in the large-scale atmospheric circulation, whereas in Group 2, the albedo feedback effect plays a more important role. Interestingly, while Group 1 models have a warm or weak bias in their Arctic SAT, Group 2 models show large cold biases. This stark difference in model bias leads us to hypothesize that for a given model, the dominant Arctic warming mechanism and trend may be dependent on the bias of the model mean state.

  19. Local warming: daily temperature change influences belief in global warming.

    Science.gov (United States)

    Li, Ye; Johnson, Eric J; Zaval, Lisa

    2011-04-01

    Although people are quite aware of global warming, their beliefs about it may be malleable; specifically, their beliefs may be constructed in response to questions about global warming. Beliefs may reflect irrelevant but salient information, such as the current day's temperature. This replacement of a more complex, less easily accessed judgment with a simple, more accessible one is known as attribute substitution. In three studies, we asked residents of the United States and Australia to report their opinions about global warming and whether the temperature on the day of the study was warmer or cooler than usual. Respondents who thought that day was warmer than usual believed more in and had greater concern about global warming than did respondents who thought that day was colder than usual. They also donated more money to a global-warming charity if they thought that day seemed warmer than usual. We used instrumental variable regression to rule out some alternative explanations.

  20. Atmospheric trace gases and global climate - A seasonal model study

    Science.gov (United States)

    Wang, Wei-Chyung; Molnar, Gyula; Ko, Malcolm K. W.; Goldenberg, Steven; Sze, Nien Dak

    1990-01-01

    Atmospheric models with seasonal cycles are used to study the possible near-future changes in latitudinal and vertical distributions of atmospheric ozone and temperature caused by increases of trace gases. It is found that increases of CFCs, CH4, and N2O may add to the surface warming from increased CO2. Calculations based on projected trends of CO2, N2O, CH4, and CFCs show that the annual mean and global mean surface temperature could warm by as much as 2.5 C by the year 2050, with larger warming at high latitudes. The results suggest that the warming in the lower stratosphere and upper troposphere is much larger than that at the surface, especially during the summer season.

  1. Atmospheric trace gases and global climate - A seasonal model study

    Science.gov (United States)

    Wang, Wei-Chyung; Molnar, Gyula; Ko, Malcolm K. W.; Goldenberg, Steven; Sze, Nien Dak

    1990-01-01

    Atmospheric models with seasonal cycles are used to study the possible near-future changes in latitudinal and vertical distributions of atmospheric ozone and temperature caused by increases of trace gases. It is found that increases of CFCs, CH4, and N2O may add to the surface warming from increased CO2. Calculations based on projected trends of CO2, N2O, CH4, and CFCs show that the annual mean and global mean surface temperature could warm by as much as 2.5 C by the year 2050, with larger warming at high latitudes. The results suggest that the warming in the lower stratosphere and upper troposphere is much larger than that at the surface, especially during the summer season.

  2. Changes in Terrestrial Water Availability under Global Warming

    Science.gov (United States)

    Lan, C. W.; Lo, M. H.; Chou, C.

    2014-12-01

    Under global warming, the annual range of precipitation is widening (Chou and Lan, 2012; Chou et al., 2013) and the frequency of precipitation extreme events also increases. Due to nonlinear responses of land hydrological process to precipitation extremes, runoff can increase exponentially, and on the hard hand, soil water storage may decline. In addition, IPCC AR5 indicates that soil moisture decreases in most areas under the global warming scenario. In this study, we use NCAR Community Land Model version 4 (CLM4) to simulate changes in terrestrial available water (TAW, defined as the precipitation minus evaporation minus runoff, and then divided by the precipitation) under global warming. Preliminary results show that the TAW has clear seasonal variations. Compared to previous studies, which do not include the runoff in the calculations of the available water, our estimates on the TAW has much less available water in high latitudes through out the year, especially under extreme precipitation events.

  3. determinants of child mortality in a rural ugandan community

    African Journals Online (AJOL)

    2001-12-12

    Dec 12, 2001 ... parental education, being born to adolescent mothers or mothers aged 35 or more. Unconditional logistic ... Seasonal mortality followed the El Nino rainfall pattern. Finally, there .... Current maternal age (years). 14-19. 20-24.

  4. Five years of phenology observations from a mixed-grass prairie exposed to warming and elevated CO2

    Science.gov (United States)

    Atmospheric CO2 concentrations have been steadily increasing since the Industrial Era and contribute to concurrent increases in global temperatures. Many observational studies suggest climate warming alone contributes to a longer growing season. To determine the relative effect of warming on plant p...

  5. Committed warming inferred from observations

    Science.gov (United States)

    Mauritsen, Thorsten; Pincus, Robert

    2017-09-01

    Due to the lifetime of CO2, the thermal inertia of the oceans, and the temporary impacts of short-lived aerosols and reactive greenhouse gases, the Earth’s climate is not equilibrated with anthropogenic forcing. As a result, even if fossil-fuel emissions were to suddenly cease, some level of committed warming is expected due to past emissions as studied previously using climate models. Here, we provide an observational-based quantification of this committed warming using the instrument record of global-mean warming, recently improved estimates of Earth’s energy imbalance, and estimates of radiative forcing from the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Compared with pre-industrial levels, we find a committed warming of 1.5 K (0.9-3.6, 5th-95th percentile) at equilibrium, and of 1.3 K (0.9-2.3) within this century. However, when assuming that ocean carbon uptake cancels remnant greenhouse gas-induced warming on centennial timescales, committed warming is reduced to 1.1 K (0.7-1.8). In the latter case there is a 13% risk that committed warming already exceeds the 1.5 K target set in Paris. Regular updates of these observationally constrained committed warming estimates, although simplistic, can provide transparent guidance as uncertainty regarding transient climate sensitivity inevitably narrows and the understanding of the limitations of the framework is advanced.

  6. Contrasting patterns of litterfall seasonality and seasonal changes in litter decomposability in a tropical rainforest region

    Directory of Open Access Journals (Sweden)

    S. A. Parsons

    2014-06-01

    Full Text Available The seasonality of litter inputs in forests has important implications for understanding ecosystem processes and biogeochemical cycles. We quantified the drivers of seasonality in litterfall and leaf decomposability, using plots throughout the Australian wet tropical region. Litter fell mostly in the summer (wet, warm months in the region, but other peaks occurred throughout the year. Litterfall seasonality was modelled well with the level of deciduousness of the site (plots with more deciduous species had lower seasonality than evergreen plots, temperature (higher seasonality in the uplands, disturbance (lower seasonality with more early secondary species and soil fertility (higher seasonality with higher N : P/P limitation (SL total litterfall model 1 = deciduousness + soil N : P + early secondary sp: r2 = 0.63, n = 30 plots; model 2 = temperature + early secondary sp. + soil N : P: r2 = 0.54, n = 30; SL leaf = temperature + early secondary sp. + rainfall seasonality: r2 = 0.39, n = 30. Leaf litter decomposability was lower in the dry season than in the wet season, driven by higher phenolic concentrations in the dry, with the difference exacerbated particularly by lower dry season moisture. Our results are contrary to the global trend for tropical rainforests; in that seasonality of litterfall inputs were generally higher in wetter, cooler, evergreen forests, compared to generally drier, warmer, semi-deciduous sites that had more uniform monthly inputs. We consider this due to more diverse litter shedding patterns in semi-deciduous and raingreen rainforest sites, and an important consideration for ecosystem modellers. Seasonal changes in litter quality are likely to have impacts on decomposition and biogeochemical cycles in these forests due to the litter that falls in the dry being more recalcitrant to decay.

  7. The tropical Pacific as a key pacemaker of the variable rates of global warming

    Science.gov (United States)

    Kosaka, Yu; Xie, Shang-Ping

    2016-09-01

    Global mean surface temperature change over the past 120 years resembles a rising staircase: the overall warming trend was interrupted by the mid-twentieth-century big hiatus and the warming slowdown since about 1998. The Interdecadal Pacific Oscillation has been implicated in modulations of global mean surface temperatures, but which part of the mode drives the variability in warming rates is unclear. Here we present a successful simulation of the global warming staircase since 1900 with a global ocean-atmosphere coupled model where tropical Pacific sea surface temperatures are forced to follow the observed evolution. Without prescribed tropical Pacific variability, the same model, on average, produces a continual warming trend that accelerates after the 1960s. We identify four events where the tropical Pacific decadal cooling markedly slowed down the warming trend. Matching the observed spatial and seasonal fingerprints we identify the tropical Pacific as a key pacemaker of the warming staircase, with radiative forcing driving the overall warming trend. Specifically, tropical Pacific variability amplifies the first warming epoch of the 1910s-1940s and determines the timing when the big hiatus starts and ends. Our method of removing internal variability from the observed record can be used for real-time monitoring of anthropogenic warming.

  8. Are Sierran Lakes Warming as a Result of Climate Change? The Effects of Climate Warming and Variation in Precipitation on Water Temperature in a Snowmelt-Dominated Lake

    Science.gov (United States)

    Sadro, S.; Melack, J. M.; Sickman, J. O.; Skeen, K.

    2016-12-01

    Water temperature regulates a broad range of fundamental ecosystem processes in lakes. While climate can be an important factor regulating lake temperatures, heterogeneity in the warming response of lakes is large, and variation in precipitation is rarely considered. We analyzed three decades of climate and water temperature data from a high-elevation catchment in the southern Sierra Nevada of California to illustrate the magnitude of warming taking place during different seasons and the role of precipitation in regulating lake temperatures. Significant climate warming trends were evident during all seasons except spring. Nighttime rates of climate warming were approximately 25% higher than daytime rates. Spatial patterns in warming were elevation dependent, with rates of temperature increase higher at sites above 2800 m.a.s.l. than below. Although interannual variation in snow deposition was high, the frequency and severity of recent droughts has contributed to a significant 3.4 mm year -1 decline in snow water equivalent over the last century. Snow accumulation, more than any other climate factor, regulated lake temperature; 94% of variation in summer lake temperature was regulated by precipitation as snow. For every 100 mm decrease in snow water equivalent there was a 0.62 ° increase in lake temperature. Drought years amplify warming in lakes by reducing the role of cold spring meltwaters in lake energy budgets and prolonging the ice-free period during which lakes warm. The combination of declining winter snowpack and warming air temperatures has the capacity to amplify the effect of climate warming on lake temperatures during drought years. Interactions among climatic factors need to be considered when evaluating ecosystem level effects, especially in mountain regions. For mountain lakes already affected by drought, continued climate warming during spring and autumn has the greatest potential to impact mean lake temperatures.

  9. Global warming reduces plant reproductive output for temperate multi-inflorescence species on the Tibetan plateau.

    Science.gov (United States)

    Liu, Yinzhan; Mu, Junpeng; Niklas, Karl J; Li, Guoyong; Sun, Shucun

    2012-07-01

    • Temperature is projected to increase more during the winter than during the summer in cold regions. The effects of winter warming on reproductive effort have not been examined for temperate plant species. • Here, we report the results of experimentally induced seasonal winter warming (0.4 and 2.4°C increases in growing and nongrowing seasons, respectively, using warmed and ambient open-top chambers in a Tibetan Plateau alpine meadow) for nine indeterminate-growing species producing multiple (single-flowered or multi-flowered) inflorescences and three determinate-growing species producing single inflorescences after a 3-yr period of warming. • Warming reduced significantly flower number and seed production per plant for all nine multi-inflorescence species, but not for the three single-inflorescence species. Warming had an insignificant effect on the fruit to flower number ratio, seed size and seed number per fruit among species. The reduction in seed production was largely attributable to the decline in flower number per plant. The flowering onset time was unaffected for nine of the 12 species. Therefore, the decline in flower production and seed production in response to winter warming probably reflects a physiological response (e.g. metabolic changes associated with flower production). • Collectively, the data indicate that global warming may reduce flower and seed production for temperate herbaceous species and will probably have a differential effect on single- vs multi-inflorescence species. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

  10. Warm dense crystallography

    Science.gov (United States)

    Valenza, Ryan A.; Seidler, Gerald T.

    2016-03-01

    The intense femtosecond-scale pulses from x-ray free electron lasers (XFELs) are able to create and interrogate interesting states of matter characterized by long-lived nonequilibrium semicore or core electron occupancies or by the heating of dense phases via the relaxation cascade initiated by the photoelectric effect. We address here the latter case of "warm dense matter" (WDM) and investigate the observable consequences of x-ray heating of the electronic degrees of freedom in crystalline systems. We report temperature-dependent density functional theory calculations for the x-ray diffraction from crystalline LiF, graphite, diamond, and Be. We find testable, strong signatures of condensed-phase effects that emphasize the importance of wide-angle scattering to study nonequilibrium states. These results also suggest that the reorganization of the valence electron density at eV-scale temperatures presents a confounding factor to achieving atomic resolution in macromolecular serial femtosecond crystallography (SFX) studies at XFELs, as performed under the "diffract before destroy" paradigm.

  11. Enhanced greenhouse gas emissions from the Arctic with experimental warming

    Science.gov (United States)

    Voigt, Carolina; Lamprecht, Richard E.; Marushchak, Maija E.; Lind, Saara E.; Novakovskiy, Alexander; Aurela, Mika; Martikainen, Pertti J.; Biasi, Christina

    2017-04-01

    Temperatures in the Arctic are projected to increase more rapidly than in lower latitudes. With temperature being a key factor for regulating biogeochemical processes in ecosystems, even a subtle temperature increase might promote the release of greenhouse gases (GHGs) to the atmosphere. Usually, carbon dioxide (CO2) and methane (CH4) are the GHGs dominating the climatic impact of tundra. However, bare, patterned ground features in the Arctic have recently been identified as hot spots for nitrous oxide (N2O). N2O is a potent greenhouse gas, which is almost 300 times more effective in its global warming potential than CO2; but studies on arctic N2O fluxes are rare. In this study we examined the impact of temperature increase on the seasonal GHG balance of all three important GHGs (CO2, CH4 and N2O) from three tundra surface types (vegetated peat soils, unvegetated peat soils, upland mineral soils) in the Russian Arctic (67˚ 03' N 62˚ 55' E), during the course of two growing seasons. We deployed open-top chambers (OTCs), inducing air and soil surface warming, thus mimicking predicted warming scenarios. We combined detailed CO2, CH4 and N2O flux studies with concentration measurements of these gases within the soil profile down to the active layer-permafrost interface, and complemented these GHG measurements with detailed soil nutrient (nitrate and ammonium) and dissolved organic carbon (DOC) measurements in the soil pore water profile. In our study, gentle air warming (˜1.0 ˚ C) increased the seasonal GHG release of all dominant surface types: the GHG budget of vegetated peat and mineral soils, which together cover more than 80 % of the land area in our study region, shifted from a sink to a source of -300 to 144 g CO2-eq m-2 and from -198 to 105 g CO2-eq m-2, respectively. While the positive warming response was governed by CO2, we provide here the first in situ evidence that warming increases arctic N2O emissions: Warming did not only enhance N2O emissions from

  12. Cold months in a warming climate

    Science.gov (United States)

    Räisänen, Jouni; Ylhäisi, Jussi S.

    2011-11-01

    The frequency of cold months in the 21st century is studied using the CMIP3 ensemble of climate model simulations, using month-, location- and model-specific threshold temperatures derived from the simulated 20th century climate. Unsurprisingly, cold months are projected to become less common, but not non-existent, under continued global warming. As a multi-model mean over the global land area excluding Antarctica and under the SRES A1B scenario, 14% of the months during the years 2011-2050 are simulated to be colder than the 20th century median for the same month, 1.3% colder than the 10th percentile, and 0.1% record cold. The geographic and seasonal variations in the frequency of cold months are strongly modulated by variations in the magnitude of interannual variability. Thus, for example, cold months are most infrequently simulated over the tropical oceans where the variability is smallest, not over the Arctic where the warming is largest.

  13. Influence of heat wave definitions to the added effect of heat waves on daily mortality in Nanjing, China.

    Science.gov (United States)

    Chen, Kai; Bi, Jun; Chen, Jin; Chen, Xiaodong; Huang, Lei; Zhou, Lian

    2015-02-15

    Few studies have explored the added effect of heat waves, especially in China. Moreover, no prior studies have assessed whether the choice of heat wave definitions affected this added effect. This study compared the associations between heat waves defined by different heat wave definitions (HWs) and cause-specific mortality in warm season in Nanjing, China. A distributed lag model was applied to evaluate the differences in daily mortality during heat-wave days (defined using 15 HWs) compared with non-heat-wave days in Nanjing, during 2007 to 2013. For different HWs, model fits were examined by the Akaike Information Criterion for quasi-Poisson and effects were compared by stratified analysis and bootstrapping. In addition, we explored the effect modifications by individual characteristics under different HWs. Different HWs resulted in considerable differences in associations between heat waves and mortality. Heat waves defined as ≥4 consecutive days with daily average temperature >98th percentile had the best model fit and were associated with an increase of 24.6% (95% CI: 15.6%, 34.3%) total mortality, 46.9% (95% CI: 33.0%, 62.3%) cardiovascular mortality, 32.0% (95% CI: 8.5%, 60.5%) respiratory mortality, 51.3% (95% CI: 23.4%, 85.6%) stroke mortality, 63.4% (95% CI: 41.5%, 88.8%) ischemic heart disease mortality, and 47.6% (95% CI: 14.5%, 90.3%) chronic obstructive pulmonary disease mortality at lag day 2. Under different HWs, added effects of heat waves on mortality were higher for females versus males, the elderly versus young residents, and people with low education versus those with high education. Results were less sensitive to the inclusion of air pollutants. Heat wave definition plays a critical role in the relationship between heat waves and mortality. Selecting an appropriate definition of heat waves is therefore important to design local heat warning systems and to reduce the burden of disease during heat waves. Copyright © 2014 Elsevier B.V. All

  14. Projected changes in prevailing winds for transatlantic migratory birds under global warming.

    Science.gov (United States)

    La Sorte, Frank A; Fink, Daniel

    2017-03-01

    A number of terrestrial bird species that breed in North America cross the Atlantic Ocean during autumn migration when travelling to their non-breeding grounds in the Caribbean or South America. When conducting oceanic crossings, migratory birds tend to associate with mild or supportive winds, whose speed and direction may change under global warming. The implications of these changes for transoceanic migratory bird populations have not been addressed. We used occurrence information from eBird (1950-2015) to estimate the geographical location of population centres at a daily temporal resolution across the annual cycle for 10 transatlantic migratory bird species. We used this information to estimate the location and timing of autumn migration within the transatlantic flyway. We estimated how prevailing winds are projected to change within the transatlantic flyway during this time using daily wind speed anomalies (1996-2005 and 2091-2100) from 29 Atmosphere-Ocean General Circulation Models implemented under CMIP5. Autumn transatlantic migrants have the potential to encounter strong westerly crosswinds early in their transatlantic journey at intermediate and especially high migration altitudes, strong headwinds at low and intermediate migration altitudes within the Caribbean that increase in strength as the season progresses, and weak tailwinds at intermediate and high migration altitudes east of the Caribbean. The CMIP5 simulations suggest that, during this century, the likelihood of autumn transatlantic migrants encountering strong westerly crosswinds will diminish. As global warming progresses, the need for species to compensate or drift under the influence of strong westerly crosswinds during the initial phase of their autumn transatlantic journey may be diminished. Existing strategies that promote headwind avoidance and tailwind assistance will likely remain valid. Thus, climate change may reduce time and energy requirements and the chance of mortality or

  15. Recent warming of lake Kivu.

    Directory of Open Access Journals (Sweden)

    Sergei Katsev

    Full Text Available Lake Kivu in East Africa has gained notoriety for its prodigious amounts of dissolved methane and dangers of limnic eruption. Being meromictic, it is also expected to accumulate heat due to rising regional air temperatures. To investigate the warming trend and distinguish between atmospheric and geothermal heating sources, we compiled historical temperature data, performed measurements with logging instruments, and simulated heat propagation. We also performed isotopic analyses of water from the lake's main basin and isolated Kabuno Bay. The results reveal that the lake surface is warming at the rate of 0.12°C per decade, which matches the warming rates in other East African lakes. Temperatures increase throughout the entire water column. Though warming is strongest near the surface, warming rates in the deep waters cannot be accounted for solely by propagation of atmospheric heat at presently assumed rates of vertical mixing. Unless the transport rates are significantly higher than presently believed, this indicates significant contributions from subterranean heat sources. Temperature time series in the deep monimolimnion suggest evidence of convection. The progressive deepening of the depth of temperature minimum in the water column is expected to accelerate the warming in deeper waters. The warming trend, however, is unlikely to strongly affect the physical stability of the lake, which depends primarily on salinity gradient.

  16. Global Warming Attenuates the Tropical Atlantic-Pacific Teleconnection.

    Science.gov (United States)

    Jia, Fan; Wu, Lixin; Gan, Bolan; Cai, Wenju

    2016-02-03

    Changes in global sea surface temperature (SST) since the end of last century display a pattern of widespread warming intercepted by cooling in the eastern equatorial Pacific and western coasts of the American continent. Studies have suggested that the cooling in the eastern equatorial Pacific may be partly induced by warming in the North Atlantic. However, it remains unknown how stable this inter-tropical teleconnection will be under global warming. Here we show that the inter-tropical teleconnection from the tropical Atlantic to Pacific weakens substantially as the CO2 concentration increases. This reduced impact is related to the El Niño-like warming of the tropical Pacific mean state, which leads to limited seasonal migration of the Pacific inter-tropical convergence zone (ITCZ) and weakened ocean heat transport. A fast decay of the tropical Atlantic SST anomalies in a warmer climate also contributes to the weakened teleconnection. Our study suggests that as greenhouse warming continues, the trend in the tropical Pacific as well as the development of ENSO will be less frequently interrupted by the Atlantic because of this attenuation. The weakened teleconnection is also supported by CMIP5 models, although only a few of these models can capture this inter-tropical teleconnection.

  17. Propagation of planktonic copepods: production and mortality of eggs

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Møhlenberg, Flemming; Tiselius, Peter

    1988-01-01

    Data on fecundity and egg mortality of neritic copepods were collected in various seasons, areas and under various hydrographical conditions. On a seasonal basis variations in fecundity (F) were related to temperature rather than to the abundance of phytoplankton (P). However, a strong correlatio...

  18. Responses of Ecosystem CO2 Fluxes to Short-Term Experimental Warming and Nitrogen Enrichment in an Alpine Meadow, Northern Tibet Plateau

    Science.gov (United States)

    Shi, Peili; Jiang, Jing; Song, Minghua; Xiong, Dingpeng; Ma, Weiling; Fu, Gang; Zhang, Xianzhou; Shen, Zhenxi

    2013-01-01

    Over the past decades, the Tibetan Plateau has experienced pronounced warming, yet the extent to which warming will affect alpine ecosystems depends on how warming interacts with other influential global change factors, such as nitrogen (N) deposition. A long-term warming and N manipulation experiment was established to investigate the interactive effects of warming and N deposition on alpine meadow. Open-top chambers were used to simulate warming. N addition, warming, N addition × warming, and a control were set up. In OTCs, daytime air and soil temperature were warmed by 2.0°C and 1.6°C above ambient conditions, but soil moisture was decreased by 4.95 m3 m−3. N addition enhanced ecosystem respiration (Reco); nevertheless, warming significantly decreased Reco. The decline of Reco resulting from warming was cancelled out by N addition in late growing season. Our results suggested that N addition enhanced Reco by increasing soil N availability and plant production, whereas warming decreased Reco through lowering soil moisture, soil N supply potential, and suppression of plant activity. Furthermore, season-specific responses of Reco indicated that warming and N deposition caused by future global change may have complicated influence on carbon cycles in alpine ecosystems. PMID:24459432

  19. Responses of Ecosystem CO2 Fluxes to Short-Term Experimental Warming and Nitrogen Enrichment in an Alpine Meadow, Northern Tibet Plateau

    Directory of Open Access Journals (Sweden)

    Ning Zong

    2013-01-01

    Full Text Available Over the past decades, the Tibetan Plateau has experienced pronounced warming, yet the extent to which warming will affect alpine ecosystems depends on how warming interacts with other influential global change factors, such as nitrogen (N deposition. A long-term warming and N manipulation experiment was established to investigate the interactive effects of warming and N deposition on alpine meadow. Open-top chambers were used to simulate warming. N addition, warming, N addition × warming, and a control were set up. In OTCs, daytime air and soil temperature were warmed by 2.0°C and 1.6°C above ambient conditions, but soil moisture was decreased by 4.95 m3 m−3. N addition enhanced ecosystem respiration (Reco; nevertheless, warming significantly decreased Reco. The decline of Reco resulting from warming was cancelled out by N addition in late growing season. Our results suggested that N addition enhanced Reco by increasing soil N availability and plant production, whereas warming decreased Reco through lowering soil moisture, soil N supply potential, and suppression of plant activity. Furthermore, season-specific responses of Reco indicated that warming and N deposition caused by future global change may have complicated influence on carbon cycles in alpine ecosystems.

  20. Global warming: the complete briefing

    Energy Technology Data Exchange (ETDEWEB)

    Houghton, J.

    1994-01-01

    The science of global warming, its impacts, and what action might be taken, are described in this book, in a way which the intelligent non-scientist can understand. It also examines ethical and moral issues of concern about global warming, considering mankind as stewards of the earth. Chapter headings of the book are: global warming and climate change; the greenhouse effect; the greenhouse gases; climates of the past; modelling the climate; climate change and business-as-usual; the impacts of climate change; why should we be concerned ; weighing the uncertainty; action to slow and stabilize climate change; energy and transport for the future; and the global village.

  1. salinity Budget analysis of of Western Pacific Warm Pool

    Science.gov (United States)

    Gao, Shan; nie, xunwei; Qu, Tangdong

    2013-04-01

    Western pacific warm pool plays an important role in governing global climate variability. In particular, the unique salinity structures of warm pool, barrier layer and salinity front, have significant impacts on the heat content accumulation and zonal migration of warm pool surface water, which further modulate the formation and development of tropical climate phenomenon, such as El Niño, MJO and EAM. In order to have better understanding of how warm pool salinity contributes to climate change the salinity budget of warm pool are investigated using results from a model of the Consortium for Estimating the Circulation and Climate of the Ocean (ECCO). The results show that the salinity budget of warm pool and its components have significant seasonal and annual variability. The surface freshwater flux is the dominant element of salinity budget, which is well balanced by the other ocean dynamic terms. However among all the terms of ocean dynamics, mixing is most significant, whereas advection and entrainment are not dominant, unlike most other region. The further analysis of lagged correlation coefficient between the salinity budget, salinity budget components and NIÑO 3.4 reveals that the salinity budget is highly related to El Niño and Southern Oscillation (ENSO). The results indicate that the annual variability of warm pool salinity budget has a notable correlation coefficient with NIÑO 3.4 (0.7); Mealwhile,variabilities of each components of Ocean dynamics,including diffusion, advection and mixing are found to be highly correlated to ENSO.The local barrier layer is believed to be a major reason.

  2. From vegetation zones to climatypes: Effects of climate warming on Siberian ecosystems

    Science.gov (United States)

    N. M. Tchebakova; G. E. Rehfeldt; E. I. Parfenova

    2010-01-01

    Evidence for global warming over the past 200 years is overwhelming, based on both direct weather observation and indirect physical and biological indicators such as retreating glaciers and snow/ice cover, increasing sea level, and longer growing seasons (IPCC 2001, 2007). On the background of global warming at a rate of 0.6°C during the twentieth century (IPCC 2001),...

  3. Species-specific vulnerability of Arctic copepods to oil contamination and global warming

    DEFF Research Database (Denmark)

    Dinh, Khuong Van; Nielsen, Torkel Gissel

    Arctic ecosystems are predicted to have more severe effects from global warming as during the last decades the temperatures have increased in this region at a rate of 2-4 times higher than the global average. In addition, oil exploitation and shipping activities in the Arctic are predicted...... to increase under global warming as the result of the retreat of sea ice, posing the risk of oil contamination. It is poorly known how cold adapted copepods in the Arctic deal with the combined effects of global warming and oil exposure. To address this, we exposed females of two copepods species Calanus...... of temperatures. Notably, exposure to high pyrene resulted in ca. 70% of mortality in C. finmarchicus, the species with North Atlantic Origin, that was two times higher than the mortality observed for C. glacialis, the true Arctic species. These results suggest that extreme temperature under global warming...

  4. Warming in the Yukon River Basin is Likely to Release Substantial Amounts of Soil Organic Carbon

    Science.gov (United States)

    Juday, G. P.; Huntington, T. G.

    2005-12-01

    In recent decades the Yukon River Basin (YRB) in northwestern Canada and central Alaska has experienced a substantial warming trend resulting in a variety of geophysical and biological responses. Climatologic measurements consistent with rapid warming in the YRB during the last several decades of the 20th century include surface air temperature (especially daily minima), number of frost-free days, and the number of very warm days. During the 20th century daily maxima in the warm season in the YRB have increased only weakly, and modest autumn cooling occurred. Indirect indicators of warming include shrinkage in lake area, decreases in glacier mass, increased fire frequency and annual area burned, and changes in permafrost thickness and permafrost temperature. Changes in tree growth rates and susceptibility to pests have been related to warming and drying in interior Alaska. Oral histories of Alaska Natives have also revealed many other warming related changes in the YRB. If ongoing warming trends continue there is a concern that large stores of soil organic carbon (SOC) will be at risk for release to the atmosphere through heterotrophic decomposition. Warming tends to accelerate microbial decomposition at a faster rate than net primary productivity. One of the most important effects of warming in the YRB is likely to be its influence on the hydrologic and cryospheric regimes. Warming may be accompanied by soil drying and lowering of the water table in wetlands and lakes exposing more SOC to aerobic decomposition. A substantial portion of the YRB is underlain by permafrost that thaws to a variable depth (active layer) each summer. Increasing the thickness of the active layer exposes more SOC to microbial decomposition. Increasing the burned area results in direct SOC losses by oxidation during the fire and decreases albedo that warms surface soils and increases the thickness of the active layer. Warming and increasing length of the growing season increases seasonal

  5. Seasonal Allergies (Hay Fever)

    Science.gov (United States)

    ... 1- to 2-Year-Old Seasonal Allergies (Hay Fever) KidsHealth > For Parents > Seasonal Allergies (Hay Fever) Print A A A What's in this article? ... are at work. Seasonal allergies , sometimes called "hay fever" or seasonal allergic rhinitis, are allergy symptoms that ...

  6. Cropping system innovation for coping with climatic warming in China

    Directory of Open Access Journals (Sweden)

    Aixing Deng

    2017-04-01

    Full Text Available China is becoming the largest grain producing and carbon-emitting country in the world, with a steady increase in population and economic development. A review of Chinese experiences in ensuring food self-sufficiency and reducing carbon emission in the agricultural sector can provide a valuable reference for similar countries and regions. According to a comprehensive review of previous publications and recent field observations, China has experienced on average a larger and faster climatic warming trend than the global trend, and there are large uncertainties in precipitation change, which shows a non-significantly increasing trend. Existing evidence shows that the effects of climatic warming on major staple crop production in China could be markedly negative or positive, depending on the specific cropping region, season, and crop. However, historical data analysis and field warming experiments have shown that moderate warming, of less than 2.0 °C, could benefit crop production in China overall. During the most recent warming decades, China has made successful adaptations in cropping systems, such as new cultivar breeding, cropping region adjustment, and cropping practice optimization, to exploit the positive rather than to avoid the negative effects of climatic warming on crop growth. All of these successful adaptations have greatly increased crop yield, leading to higher resource use efficiency as well as greatly increased soil organic carbon content with reduced greenhouse gas emissions. Under the warming climate, China has not only achieved great successes in crop production but also realized a large advance in greenhouse gas emission mitigation. Chinese experiences in cropping system innovation for coping with climatic warming demonstrate that food security and climatic warming mitigation can be synergized through policy, knowledge, and technological innovation. With the increasingly critical status of food security and climatic warming

  7. A novel visualisation tool for climate services: a case study of temperature extremes and human mortality in Europe

    Science.gov (United States)

    Lowe, R.; Ballester, J.; Robine, J.; Herrmann, F. R.; Jupp, T. E.; Stephenson, D.; Rodó, X.

    2013-12-01

    Users of climate information often require probabilistic information on which to base their decisions. However, communicating information contained within a probabilistic forecast presents a challenge. In this paper we demonstrate a novel visualisation technique to display ternary probabilistic forecasts on a map in order to inform decision making. In this method, ternary probabilistic forecasts, which assign probabilities to a set of three outcomes (e.g. low, medium, and high risk), are considered as a point in a triangle of barycentric coordinates. This allows a unique colour to be assigned to each forecast from a continuum of colours defined on the triangle. Colour saturation increases with information gain relative to the reference forecast (i.e. the long term average). This provides additional information to decision makers compared with conventional methods used in seasonal climate forecasting, where one colour is used to represent one forecast category on a forecast map (e.g. red = ';dry'). We use the tool to present climate-related mortality projections across Europe. Temperature and humidity are related to human mortality via location-specific transfer functions, calculated using historical data. Daily mortality data at the NUTS2 level for 16 countries in Europe were obtain from 1998-2005. Transfer functions were calculated for 54 aggregations in Europe, defined using criteria related to population and climatological similarities. Aggregations are restricted to fall within political boundaries to avoid problems related to varying adaptation policies between countries. A statistical model is fit to cold and warm tails to estimate future mortality using forecast temperatures, in a Bayesian probabilistic framework. Using predefined categories of temperature-related mortality risk, we present maps of probabilistic projections for human mortality at seasonal to decadal time scales. We demonstrate the information gained from using this technique compared to more

  8. A Warm and Cleaner Winter

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Beijing municipal and district governments have taken measures to keep residents warm and the winter sky blue In a bungalow in Xisi North Fifth Alley in the Xicheng District of Beijing,Li has lived for nearly seven decades.

  9. Snow cover and extreme winter warming events control flower abundance of some, but not all species in high arctic Svalbard

    DEFF Research Database (Denmark)

    Semenchuk, Philipp R.; Elberling, Bo; Cooper, Elisabeth J.

    2013-01-01

    frequent extreme winter warming events. Flower production of many Arctic plants is dependent on melt out timing, since season length determines resource availability for flower preformation. We erected snow fences to increase snow depth and shorten growing season, and counted flowers of six species over 5...

  10. Arctic dimension of global warming

    Directory of Open Access Journals (Sweden)

    G. V. Alekseev

    2014-01-01

    Full Text Available A brief assessment of the global warming in the Arctic climate system with the emphasis on sea ice is presented. The Arctic region is coupled to the global climate system by the atmosphere and ocean circulation that providesa major contribution to the Arctic energy budget. On this basis using of special indices it is shown that amplification of warming in the Arctic is associated with the increasing of meridional heat transport from the low latitudes.

  11. Media narratives of global warming

    Energy Technology Data Exchange (ETDEWEB)

    Meisner, M. [Syracuse Univ., Syracuse, NY (United States)

    2000-06-01

    The way in which the North American print media are representing global warming was the focus of this paper. It was suggested that the way in which the media presents the issue and proposed responses to it, will influence how the public and decision-makers perceive and respond to the problem. This paper also presented examples demonstrating how nature and humanity's relationship to nature are being presented and what types of responses to global warming are being presented. The issue of who is responsible for acting to prevent or mitigate climate change was also discussed. It was shown that media narratives of global warming are not just stories of scientists debating the existence of global warming, but that they now largely accept global warming as a reality. However, the media continue to construct the problem in narrow technical, economic and anthropocentric terms. Mass media interpretation of global warming offer up a limited selection of problem definitions, reasons for acting and ways of addressing the problem. It was cautioned that this approach will likely promote futility, denial and apathy on the part of the public. 21 refs.

  12. Daily ocean monitoring since the 1860s shows record warming of northern European seas

    DEFF Research Database (Denmark)

    MacKenzie, Brian; Schiedek, D.

    2007-01-01

    temperature more directly affects biological responses and species interactions. Here, we investigate historical variability in regional sea surface temperature in two large heavily exploited marine ecosystems and compare these variations with expected rates of temperature change for the 21st century. We use...... rate, which is expected to occur during the 21st century and summer temperatures have risen two to five times faster than those in other seasons. These warm temperatures and rates of change are due partly to an increase in the frequency of extremely warm years. The recent warming event is exceeding...

  13. Warming effects on photosynthesis of subtropical tree species: a translocation experiment along an altitudinal gradient

    Science.gov (United States)

    Li, Yiyong; Liu, Juxiu; Zhou, Guoyi; Huang, Wenjuan; Duan, Honglang

    2016-04-01

    Ongoing climate warming induced by human activities may have great impacts on trees, yet it remains unresolved how subtropical tree species respond to rising temperature in the field. Here, we used downward translocation to investigate the effects of climate warming on leaf photosynthesis of six common tree species in subtropical China. During the experimental period between 2012 and 2014, the mean average photosynthetic rates (Asat) under saturating light for Schima superba, Machilus breviflora, Pinus massoniana and Ardisia lindleyana in the warm site were7%, 19%, 20% and 29% higher than those in the control site. In contrast, seasonal Asat for Castanopsis hystrix in the warm site were lower compared to the control site. Changes in Asat in response to translocation were mainly associated with those in leaf stomatal conductance (gs) and photosynthetic capacity (RuBP carboxylation, RuBP regeneration capacity). Our results imply that climate warming could have potential impacts on species composition and community structure in subtropical forests.

  14. Warming effects on photosynthesis of subtropical tree species: a translocation experiment along an altitudinal gradient.

    Science.gov (United States)

    Li, Yiyong; Liu, Juxiu; Zhou, Guoyi; Huang, Wenjuan; Duan, Honglang

    2016-04-22

    Ongoing climate warming induced by human activities may have great impacts on trees, yet it remains unresolved how subtropical tree species respond to rising temperature in the field. Here, we used downward translocation to investigate the effects of climate warming on leaf photosynthesis of six common tree species in subtropical China. During the experimental period between 2012 and 2014, the mean average photosynthetic rates (Asat) under saturating light for Schima superba, Machilus breviflora, Pinus massoniana and Ardisia lindleyana in the warm site were7%, 19%, 20% and 29% higher than those in the control site. In contrast, seasonal Asat for Castanopsis hystrix in the warm site were lower compared to the control site. Changes in Asat in response to translocation were mainly associated with those in leaf stomatal conductance (gs) and photosynthetic capacity (RuBP carboxylation, RuBP regeneration capacity). Our results imply that climate warming could have potential impacts on species composition and community structure in subtropical forests.

  15. [Effects of Warming and Straw Application on Soil Respiration and Enzyme Activity in a Winter Wheat Cropland].

    Science.gov (United States)

    Chen, Shu-tao; Sang, Lin; Zhang, Xu; Hu, Zheng-hua

    2016-02-15

    In order to investigate the effects of warming and straw application on soil respiration and enzyme activity, a field experiment was performed from November 2014 to May 2015. Four treatments, which were control (CK), warming, straw application, and warming and straw application, were arranged in field. Seasonal variability in soil respiration, soil temperature and soil moisture for different treatments were measured. Urease, invertase, and catalase activities for different treatments were measured at the elongation, booting, and anthesis stages. The results showed that soil respiration in different treatments had similar seasonal variation patterns. Seasonal mean soil respiration rates for the CK, warming, straw application, and warming and straw application treatments were 1.46, 1.96, 1.92, and 2.45 micromol x (m2 x s)(-1), respectively. ANOVA indicated that both warming and straw applications significantly (P straw application, and warming and straw application treatments, respectively. Warming and straw applications significantly (P < 0.05) enhanced urease, invertase, and catalase activities compared to CK. The relationship between soil respiration and urease activity fitted with a linear regression function, with the P value of 0.061. The relationship between soil respiration and invertase (P = 0.013), and between soil respiration and catalase activity (P = 0.002) fitted well with linear regression functions.

  16. Century-Long Warming Trends in the Upper Water Column of Lake Tanganyika.

    Science.gov (United States)

    Kraemer, Benjamin M; Hook, Simon; Huttula, Timo; Kotilainen, Pekka; O'Reilly, Catherine M; Peltonen, Anu; Plisnier, Pierre-Denis; Sarvala, Jouko; Tamatamah, Rashid; Vadeboncoeur, Yvonne; Wehrli, Bernhard; McIntyre, Peter B

    2015-01-01

    Lake Tanganyika, the deepest and most voluminous lake in Africa, has warmed over the last century in response to climate change. Separate analyses of surface warming rates estimated from in situ instruments, satellites, and a paleolimnological temperature proxy (TEX86) disagree, leaving uncertainty about the thermal sensitivity of Lake Tanganyika to climate change. Here, we use a comprehensive database of in situ temperature data from the top 100 meters of the water column that span the lake's seasonal range and lateral extent to demonstrate that long-term temperature trends in Lake Tanganyika depend strongly on depth, season, and latitude. The observed spatiotemporal variation in surface warming rates accounts for small differences between warming rate estimates from in situ instruments and satellite data. However, after accounting for spatiotemporal variation in temperature and warming rates, the TEX86 paleolimnological proxy yields lower surface temperatures (1.46 °C lower on average) and faster warming rates (by a factor of three) than in situ measurements. Based on the ecology of Thaumarchaeota (the microbes whose biomolecules are involved with generating the TEX86 proxy), we offer a reinterpretation of the TEX86 data from Lake Tanganyika as the temperature of the low-oxygen zone, rather than of the lake surface temperature as has been suggested previously. Our analyses provide a thorough accounting of spatiotemporal variation in warming rates, offering strong evidence that thermal and ecological shifts observed in this massive tropical lake over the last century are robust and in step with global climate change.

  17. Linking carbon and water relations to drought-induced mortality in Pinus flexilis seedlings.

    Science.gov (United States)

    Reinhardt, Keith; Germino, Matthew J; Kueppers, Lara M; Domec, Jean-Christophe; Mitton, Jeffry

    2015-07-01

    Survival of tree seedlings at high elevations has been shown to be limited by thermal constraints on carbon balance, but it is unknown if carbon relations also limit seedling survival at lower elevations, where water relations may be more important. We measured and modeled carbon fluxes and water relations in first-year Pinus flexilis seedlings in garden plots just beyond the warm edge of their natural range, and compared these with dry-mass gain and survival across two summers. We hypothesized that mortality in these seedlings would be associated with declines in water relations, more so than with carbon-balance limitations. Rather than gradual declines in survivorship across growing seasons, we observed sharp, large-scale mortality episodes that occurred once volumetric soil-moisture content dropped below 10%. By this point, seedling water potentials had decreased below -5 MPa, seedling hydraulic conductivity had decreased by 90% and seedling hydraulic resistance had increased by >900%. Additionally, non-structural carbohydrates accumulated in aboveground tissues at the end of both summers, suggesting impairments in phloem-transport from needles to roots. This resulted in low carbohydrate concentrations in roots, which likely impaired root growth and water uptake at the time of critically low soil moisture. While photosynthesis and respiration on a leaf area basis remained high until critical hydraulic thresholds were exceeded, modeled seedling gross primary productivity declined steadily throughout the summers. At the time of mortality, modeled productivity was insufficient to support seedling biomass-gain rates, metabolism and secondary costs. Thus the large-scale mortality events that we observed near the end of each summer were most directly linked with acute, episodic declines in plant hydraulic function that were linked with important changes in whole-seedling carbon relations.

  18. Linking carbon and water limitations to drought-induced mortality of Pinus flexilis seedlings

    Science.gov (United States)

    Reinhardt, Keith; Germino, Matthew J.; Kueppers, Lara M.; Domec, Jean-Christophe; Mitton, Jeffry

    2015-01-01

    Survival of tree seedlings at high elevations has been shown to be limited by thermal constraints on carbon balance, but it is unknown if carbon relations also limit seedling survival at lower elevations, where water relations may be more important. We measured and modeled carbon fluxes and water relations in first-year Pinus flexilis seedlings in garden plots just beyond the warm edge of their natural range, and compared these with dry-mass gain and survival across two summers. We hypothesized that mortality in these seedlings would be associated with declines in water relations, more so than with carbon-balance limitations. Rather than gradual declines in survivorship across growing seasons, we observed sharp, large-scale mortality episodes that occurred once volumetric soil-moisture content dropped below 10%. By this point, seedling water potentials had decreased below −5 MPa, seedling hydraulic conductivity had decreased by 90% and seedling hydraulic resistance had increased by >900%. Additionally, non-structural carbohydrates accumulated in aboveground tissues at the end of both summers, suggesting impairments in phloem-transport from needles to roots. This resulted in low carbohydrate concentrations in roots, which likely impaired root growth and water uptake at the time of critically low soil moisture. While photosynthesis and respiration on a leaf area basis remained high until critical hydraulic thresholds were exceeded, modeled seedling gross primary productivity declined steadily throughout the summers. At the time of mortality, modeled productivity was insufficient to support seedling biomass-gain rates, metabolism and secondary costs. Thus the large-scale mortality events that we observed near the end of each summer were most directly linked with acute, episodic declines in plant hydraulic function that were linked with important changes in whole-seedling carbon relations.

  19. Temperature as a potent driver of regional forest drought stress and tree mortality

    Science.gov (United States)

    Williams, A. Park; Allen, Craig D.; Macalady, Alison K.; Griffin, Daniel; Woodhouse, Connie A.; Meko, David M.; Swetnam, Thomas W.; Rauscher, Sara A.; Seager, Richard; Grissino-Mayer, Henri D.; Dean, Jeffrey S.; Cook, Edward R.; Gangodagamage, Chandana; Cai, Michael; McDowell, Nate G.

    2013-01-01

    As the climate changes, drought may reduce tree productivity and survival across many forest ecosystems; however, the relative influence of specific climate parameters on forest decline is poorly understood. We derive a forest drought-stress index (FDSI) for the southwestern United States using a comprehensive tree-ring data set representing AD 1000-2007. The FDSI is approximately equally influenced by the warm-season vapour-pressure deficit (largely controlled by temperature) and cold-season precipitation, together explaining 82% of the FDSI variability. Correspondence between the FDSI and measures of forest productivity, mortality, bark-beetle outbreak and wildfire validate the FDSI as a holistic forest-vigour indicator. If the vapour-pressure deficit continues increasing as projected by climate models, the mean forest drought-stress by the 2050s will exceed that of the most severe droughts in the past 1,000 years. Collectively, the results foreshadow twenty-first-century changes in forest structures and compositions, with transition of forests in the southwestern United States, and perhaps water-limited forests globally, towards distributions unfamiliar to modern civilization.

  20. Decadal warming causes a consistent and persistent shift from heterotrophic to autotrophic respiration in contrasting permafrost ecosystems.

    Science.gov (United States)

    Hicks Pries, Caitlin E; van Logtestijn, Richard S P; Schuur, Edward A G; Natali, Susan M; Cornelissen, Johannes H C; Aerts, Rien; Dorrepaal, Ellen

    2015-12-01

    Soil carbon in permafrost ecosystems has the potential to become a major positive feedback to climate change if permafrost thaw increases heterotrophic decomposition. However, warming can also stimulate autotrophic production leading to increased ecosystem carbon storage-a negative climate change feedback. Few studies partitioning ecosystem respiration examine decadal warming effects or compare responses among ecosystems. Here, we first examined how 11 years of warming during different seasons affected autotrophic and heterotrophic respiration in a bryophyte-dominated peatland in Abisko, Sweden. We used natural abundance radiocarbon to partition ecosystem respiration into autotrophic respiration, associated with production, and heterotrophic decomposition. Summertime warming decreased the age of carbon respired by the ecosystem due to increased proportional contributions from autotrophic and young soil respiration and decreased proportional contributions from old soil. Summertime warming's large effect was due to not only warmer air temperatures during the growing season, but also to warmer deep soils year-round. Second, we compared ecosystem respiration responses between two contrasting ecosystems, the Abisko peatland and a tussock-dominated tundra in Healy, Alaska. Each ecosystem had two different timescales of warming (warming with increased respiration, increased autotrophic contributions to ecosystem respiration, and increased ratios of autotrophic to heterotrophic respiration. We did not detect an increase in old soil carbon losses with warming at either site. If increased autotrophic respiration is balanced by increased primary production, as is the case in the Healy tundra, warming will not cause these ecosystems to become growing season carbon sources. Warming instead causes a persistent shift from heterotrophic to more autotrophic control of the growing season carbon cycle in these carbon-rich permafrost ecosystems. © 2015 John Wiley & Sons Ltd.

  1. Mixed layer warming-deepening in the Mediterranean Sea and its effect on the marine environment

    Science.gov (United States)

    Rivetti, Irene; Boero, Ferdinando; Fraschetti, Simonetta; Zambianchi, Enrico; Lionello, Piero

    2015-04-01

    This work aims at investigating the evolution of the ocean mixed layer in the Mediterranean Sea and linking it to the occurrence of mass mortalities of benthic invertebrates. The temporal evolution of selected parameters describing the mixed layer and the seasonal thermocline is provided for the whole Mediterranean Sea for spring, summer and autumn and for the period 1945-2011. For this analysis all temperature profiles collected in the basin with bottles, Mechanical Bathy-Thermographs (MBT), eXpendable Bathy-Thermographs (XBT), and Conductivity-Temperature-Depth (CTD) have been used (166,990). These data have been extracted from three public sources: the MEDAR-MEDATLAS, the World Ocean Database 2013 and the MFS-VOS program. Five different methods for estimating the mixed layer depth are compared using temperature profiles collected at the DYFAMED station in the Ligurian Sea and one method, the so-called three-segment method, has been selected for a systematic analysis of the evolution of the uppermost part of the whole Mediterranean Sea. This method approximates the upper water column with three segments representing mixed layer, thermocline and deep layer and has shown to be the most suitable method for capturing the mixed layer depth for most shapes of temperature profiles. Mass mortalities events of benthic invertebrates have been identified by an extensive search of all data bases in ISI Web of Knowledge considering studies published from 1945 to 2011. Studies reporting the geographical coordinates, the timing of the events, the species involved and the depth at which signs of stress occurred have been considered. Results show a general increase of thickness and temperature of the mixed layer, deepening and cooling of the thermocline base in summer and autumn. Possible impacts of these changes are mass mortalities events of benthic invertebrates that have been documented since 1983 mainly in summer and autumn. It is also shown that most mass mortalities

  2. Predicting pneumonia and influenza mortality from morbidity data.

    Directory of Open Access Journals (Sweden)

    Lise Denoeud

    Full Text Available BACKGROUND: Few European countries conduct reactive surveillance of influenza mortality, whereas most monitor morbidity. METHODOLOGY/PRINCIPAL FINDINGS: We developed a simple model based on Poisson seasonal regression to predict excess cases of pneumonia and influenza mortality during influenza epidemics, based on influenza morbidity data and the dominant types/subtypes of circulating viruses. Epidemics were classified in three levels of mortality burden ("high", "moderate" and "low". The model was fitted on 14 influenza seasons and was validated on six subsequent influenza seasons. Five out of the six seasons in the validation set were correctly classified. The average absolute difference between observed and predicted mortality was 2.8 per 100,000 (18% of the average excess mortality and Spearman's rank correlation coefficient was 0.89 (P = 0.05. CONCLUSIONS/SIGNIFICANCE: The method described here can be used to estimate the influenza mortality burden in countries where specific pneumonia and influenza mortality surveillance data are not available.

  3. The influence of global warming on freshwater plankton communities in Britain

    OpenAIRE

    George, D. Glen

    1991-01-01

    The likely response of freshwater plankton to the direct and indirect effects of sustained global warming are summarized. The increase in CO2 posited by climatologists will have a direct effect on many biological processes, and an even more important indirect effect on the global climate. Lake plankton populations are relatively well buffered against sudden fluctuations in temperature but can react in unexpected ways to seasonal changes in the wind speed, with effects on seasonal growth and s...

  4. How warm days increase belief in global warming

    Science.gov (United States)

    Zaval, Lisa; Keenan, Elizabeth A.; Johnson, Eric J.; Weber, Elke U.

    2014-02-01

    Climate change judgements can depend on whether today seems warmer or colder than usual, termed the local warming effect. Although previous research has demonstrated that this effect occurs, studies have yet to explain why or how temperature abnormalities influence global warming attitudes. A better understanding of the underlying psychology of this effect can help explain the public's reaction to climate change and inform approaches used to communicate the phenomenon. Across five studies, we find evidence of attribute substitution, whereby individuals use less relevant but available information (for example, today's temperature) in place of more diagnostic but less accessible information (for example, global climate change patterns) when making judgements. Moreover, we rule out alternative hypotheses involving climate change labelling and lay mental models. Ultimately, we show that present temperature abnormalities are given undue weight and lead to an overestimation of the frequency of similar past events, thereby increasing belief in and concern for global warming.

  5. Off-season uptake of nitrogen in temperate heath vegetation

    DEFF Research Database (Denmark)

    Andresen, Louise Christoffersen; Michelsen, Anders

    2004-01-01

    Off-season ecosystem processes is becoming an area of increasing interest, being important when considering annual nitrogen and carbon budgets. The general assumption that physiological activity in soil microorganisms as well as vegetation is low during winter may not be justified. In this field....... Furthermore, these results should be taken into account when ecosystem responses to climatic changes such as warming are evaluated....

  6. Global warming: it's not only size that matters

    Science.gov (United States)

    Hegerl, Gabriele C.

    2011-09-01

    impacts than temperatures that have occurred frequently due to internal climate variability. Determining when exactly temperatures enter unusual ranges may be done in many different ways (and the paper shows several, and more could be imagined), but the main result of first local emergence in low latitudes remains robust. A worrying factor is that the regions where the signal is expected to emerge first, or is already emerging are largely regions in Africa, parts of South and Central America, and the Maritime Continent; regions that are vulnerable to climate change for a variety of regions (see IPCC 2007), and regions which contribute generally little to global greenhouse gas emissions. In contrast, strong emissions of greenhouse gases occur in regions of low warming-to-variability ratio. To get even closer to the relevance of this finding for impacts, it would be interesting to place the emergence of highly unusual summer temperatures in the context not of internal variability, but in the context of variability experienced by the climate system prior to the 20th century, as, e.g. documented in palaeoclimatic reconstructions and simulated in simulations of the last millennium (see Jansen et al 2007). External forcing has moved the temperature range around more strongly for some regions and in some seasons than others. For example, while reconstructions of summer temperatures in Europe appear to show small long-term variations, winter shows deep drops in temperature in the little Ice Age and a long-term increase since then (Luterbacher et al 2004), which was at least partly caused by external forcing (Hegerl et al 2011a) and therefore 'natural variability' may be different from internal variability. A further interesting question in attempts to provide a climate-based proxy for impacts of climate change is: to what extent does the rapidity of change matter, and how does it compare to trends due to natural variability? It is reasonable to assume that fast changes impact

  7. On the existence of stable seasonally varying Arctic sea ice

    CERN Document Server

    Moon, W

    2012-01-01

    Within the framework lower order thermodynamic theories for the climatic evolution of Arctic sea ice we isolate the conditions required for the existence of stable seasonally-varying ice states. This is done by constructing a two-season model from the continuously evolving theory of Eisenman and Wettlaufer (2009) and showing that the necessary and sufficient condition for stable seasonally-varying states resides in the relaxation of the constant annual average short-wave radiative forcing. This forcing is examined within the scenario of greenhouse gas warming, as a function of which stability conditions are discerned.

  8. Mortality table construction

    Science.gov (United States)

    Sutawanir

    2015-12-01

    Mortality tables play important role in actuarial studies such as life annuities, premium determination, premium reserve, valuation pension plan, pension funding. Some known mortality tables are CSO mortality table, Indonesian Mortality Table, Bowers mortality table, Japan Mortality table. For actuary applications some tables are constructed with different environment such as single decrement, double decrement, and multiple decrement. There exist two approaches in mortality table construction : mathematics approach and statistical approach. Distribution model and estimation theory are the statistical concepts that are used in mortality table construction. This article aims to discuss the statistical approach in mortality table construction. The distributional assumptions are uniform death distribution (UDD) and constant force (exponential). Moment estimation and maximum likelihood are used to estimate the mortality parameter. Moment estimation methods are easier to manipulate compared to maximum likelihood estimation (mle). However, the complete mortality data are not used in moment estimation method. Maximum likelihood exploited all available information in mortality estimation. Some mle equations are complicated and solved using numerical methods. The article focus on single decrement estimation using moment and maximum likelihood estimation. Some extension to double decrement will introduced. Simple dataset will be used to illustrated the mortality estimation, and mortality table.

  9. Changes in the Effect of Heat on Mortality in the Last 20 Years in Nine European Cities. Results from the PHASE Project

    Science.gov (United States)

    de’ Donato, Francesca K.; Leone, Michela; Scortichini, Matteo; De Sario, Manuela; Katsouyanni, Klea; Lanki, Timo; Basagaña, Xavier; Ballester, Ferran; Åström, Christofer; Paldy, Anna; Pascal, Mathilde; Gasparrini, Antonio; Menne, Bettina; Michelozzi, Paola

    2015-01-01

    The European project PHASE aims to evaluate patterns of change in the temperature–mortality relationship and in the number of deaths attributable to heat in nine European cities in two periods, before and after summer 2003 (1996–2002 and 2004–2010). We performed age-specific Poisson regression models separately in the two periods, controlling for seasonality, air pollution and time trends. Distributed lag non-linear models were used to estimate the Relative Risks of daily mortality for increases in mean temperature from the 75th to 99th percentile of the summer distribution for each city. In the recent period, a reduction in the mortality risk associated to heat was observed only in Athens, Rome and Paris, especially among the elderly. Furthermore, in terms of heat-attributable mortality, 985, 787 and 623 fewer deaths were estimated, respectively, in the three cities. In Helsinki and Stockholm, there is a suggestion of increased heat effect. Noteworthy is that an effect of heat was still present in the recent years in all cities, ranging from +11% to +35%. In Europe, considering the warming observed in recent decades and population ageing, effective intervention measures should be promoted across countries, especially targeting vulnerable subgroups of the population with lower adaptive resources. PMID:26670239

  10. Changes in the Effect of Heat on Mortality in the Last 20 Years in Nine European Cities. Results from the PHASE Project.

    Science.gov (United States)

    de' Donato, Francesca K; Leone, Michela; Scortichini, Matteo; De Sario, Manuela; Katsouyanni, Klea; Lanki, Timo; Basagaña, Xavier; Ballester, Ferran; Åström, Christofer; Paldy, Anna; Pascal, Mathilde; Gasparrini, Antonio; Menne, Bettina; Michelozzi, Paola

    2015-12-08

    The European project PHASE aims to evaluate patterns of change in the temperature-mortality relationship and in the number of deaths attributable to heat in nine European cities in two periods, before and after summer 2003 (1996-2002 and 2004-2010). We performed age-specific Poisson regression models separately in the two periods, controlling for seasonality, air pollution and time trends. Distributed lag non-linear models were used to estimate the Relative Risks of daily mortality for increases in mean temperature from the 75th to 99th percentile of the summer distribution for each city. In the recent period, a reduction in the mortality risk associated to heat was observed only in Athens, Rome and Paris, especially among the elderly. Furthermore, in terms of heat-attributable mortality, 985, 787 and 623 fewer deaths were estimated, respectively, in the three cities. In Helsinki and Stockholm, there is a suggestion of increased heat effect. Noteworthy is that an effect of heat was still present in the recent years in all cities, ranging from +11% to +35%. In Europe, considering the warming observed in recent decades and population ageing, effective intervention measures should be promoted across countries, especially targeting vulnerable subgroups of the population with lower adaptive resources.

  11. Snake mortality associated with late season radio-transmitter implantation

    Science.gov (United States)

    D. Craig Rudolph; Shirley J. Burgdorf; Richard R. Schaefer; Richard N. Conner; Robert T. Zappalorth

    1998-01-01

    Radio-telemetry is an increasingly used procedure to obtain data on the biology of free-living snakes (Reinert 1992, 1994). In Texas and Louisiana we have been using the surgical technique of Weatherhead and Anderka (1984) to implant transmitters in timber rattlesnakes (Crotalus horridus) and Louisiana pine snakes (Pituophis melanoleucus...

  12. Part 1. A time-series study of ambient air pollution and daily mortality in Shanghai, China.

    Science.gov (United States)

    Kan, Haidong; Chen, Bingheng; Zhao, Naiqing; London, Stephanie J; Song, Guixiang; Chen, Guohai; Zhang, Yunhui; Jiang, Lili

    2010-11-01

    pollutants. For mortality due to all natural causes, we also examined the associations stratified by sex and age. Stratified analyses by education level, used as a measure of socioeconomic status, were conducted as well. In addition to an analysis of the entire study period, the effects of air pollution in just the warm season (from April to September) and cool season (from October to March) were analyzed. We also examined the effects of alternative model specifications--such as lag effects of pollutants and temperature, degrees of freedom for time trend and weather conditions, statistical approaches, and averaging methods for pollutant concentrations-on the estimated effects of air pollution. We found significant associations between the air pollutants--particulate matter 10 pm or less in aerodynamic diameter (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), and ozone (O3) -and daily mortality from all natural causes and from cardiopulmonary diseases. The increased mortality risks found in the data from Shanghai were generally similar in magnitude, per concentration of pollutant, to the risks found in research from other parts of the world. An increase of 10 microg/m3 in 2-day moving average concentrations of PM10, SO2, NO2, and O3 corresponded to 0.26% (95% confidence interval [CI], 0.14-0.37), 0.95% (95% CI, 0.62-1.28), 0.97% (95% CI, 0.66-1.27), and 0.31% (95% CI, 0.04-0.58) increases, respectively, in mortality due to all natural causes. Sensitivity analyses suggested that our findings were generally insensitive to alternative model specifications. We found significant effects of the gaseous pollutants SO2 and NO2 on daily mortality after adjustment for PM10. Our analysis also provided preliminary, but not conclusive, evidence that women, older people, and people with a low level of education might be more vulnerable to air pollution than men, younger people, and people with a high level of education. In addition, the associations between air pollution and daily

  13. Phenology and global warming research in Brazil

    Science.gov (United States)

    Morellato, L. P. C.

    2009-04-01

    A recent review on South American phenology research has shown an increase in phenology papers over the last two decades, especially in this new 21st century. Nevertheless, there is a lack of long term data sets or monitoring systems, or of papers addressing plant phenology and global warming. The IPCC AR4 report from 2007 has offered indisputable evidence of regional to global-scale change in seasonality, but it is supported by plant and animal phenological data from North Hemisphere and temperate species. Information from tropical regions in general and South America in particular are sparse or lacking. Here I summarize the recent outcomes of our ongoing tropical phenology research in Brazil and its potential contribution to integrate fields and understand the effects of global warming within the tropics. The Phenology Laboratory (UNESP) is located at Rio Claro, São Paulo State, Southeastern Brazil. We are looking for trends and shifts on tropical vegetation phenology, and are exploring different methods for collecting and analyzing phenology data. The phenological studies are developed in collaboration with graduate and undergraduate students, post-docs and researchers from Brazil and around the world. We established three long term monitoring programs on Southeastern Brazil from 2000 onwards: trees from an urban garden, semideciduous forest trees, and savanna cerrado woody vegetation, all based on direct weekly to monthly observation of marked plants. We have collected some discontinuous data from Atlantic rain forest trees ranging from 5 to 8 years long. I collaborate with the longest tropical wet forest phenology monitoring system in Central Amazon, and with another long term monitoring system on semi deciduous forest from South Brazil. All research programs aim, in the long run, to monitor and detect shifts on tropical plant phenology related to climatic changes. Our first preliminary findings suggest that: (i) flowering and leafing are more affected by

  14. Climatic warming and the future of bison as grazers

    Science.gov (United States)

    Craine, Joseph M.; Towne, E. Gene; Miller, Mary; Fierer, Noah

    2015-11-01

    Climatic warming is likely to exacerbate nutritional stress and reduce weight gain in large mammalian herbivores by reducing plant nutritional quality. Yet accurate predictions of the effects of climatic warming on herbivores are limited by a poor understanding of how herbivore diet varies along climate gradients. We utilized DNA metabarcoding to reconstruct seasonal variation in the diet of North American bison (Bison bison) in two grasslands that differ in mean annual temperature by 6 °C. Here, we show that associated with greater nutritional stress in warmer climates, bison consistently consumed fewer graminoids and more shrubs and forbs, i.e. eudicots. Bison in the warmer grassland consumed a lower proportion of C3 grass, but not a greater proportion of C4 grass. Instead, bison diet in the warmer grassland had a greater proportion of N2-fixing eudicots, regularly comprising >60% of their protein intake in spring and fall. Although bison have been considered strict grazers, as climatic warming reduces grass protein concentrations, bison may have to attempt to compensate by grazing less and browsing more. Promotion of high-protein, palatable eudicots or increasing the protein concentrations of grasses will be critical to minimizing warming-imposed nutritional stress for bison and perhaps other large mammalian herbivores.

  15. Rain initiation in warm clouds

    CERN Document Server

    Dallas, Vassilios

    2010-01-01

    Assuming perfect collision efficiency, we demonstrate that turbulence can initiate and sustain rapid growth of very small water droplets in air even when these droplets are too small to cluster, and even without having to take gravity and small-scale intermittency into account. This is because the range of local Stokes numbers of identical droplets in the turbulent flow field is broad enough even when small-scale intermittency is neglected. This demonstration is given for turbulence which is one order of magnitude less intense than typically in warm clouds but with a volume fraction which, even though small, is nevertheless large enough for an estimated a priori frequency of collisions to be ten times larger than in warm clouds. However, the time of growth in these conditions turns out to be one order of magnitude smaller than in warm clouds.

  16. Seasonal thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Allen, R.D.; Kannberg, L.D.; Raymond, J.R.

    1984-05-01

    This report describes the following: (1) the US Department of Energy Seasonal Thermal Energy Storage Program, (2) aquifer thermal energy storage technology, (3) alternative STES technology, (4) foreign studies in seasonal thermal energy storage, and (5) economic assessment.

  17. [Excess mortality associated with influenza in Spain in winter 2012].

    Science.gov (United States)

    León-Gómez, Inmaculada; Delgado-Sanz, Concepción; Jiménez-Jorge, Silvia; Flores, Víctor; Simón, Fernando; Gómez-Barroso, Diana; Larrauri, Amparo; de Mateo Ontañón, Salvador

    2015-01-01

    An excess of mortality was detected in Spain in February and March 2012 by the Spanish daily mortality surveillance system and the «European monitoring of excess mortality for public health action» program. The objective of this article was to determine whether this excess could be attributed to influenza in this period. Excess mortality from all causes from 2006 to 2012 were studied using time series in the Spanish daily mortality surveillance system, and Poisson regression in the European mortality surveillance system, as well as the FluMOMO model, which estimates the mortality attributable to influenza. Excess mortality due to influenza and pneumonia attributable to influenza were studied by a modification of the Serfling model. To detect the periods of excess, we compared observed and expected mortality. In February and March 2012, both the Spanish daily mortality surveillance system and the European mortality surveillance system detected a mortality excess of 8,110 and 10,872 deaths (mortality ratio (MR): 1.22 (95% CI:1.21-1.23) and 1.32 (95% CI: 1.29-1.31), respectively). In the 2011-12 season, the FluMOMO model identified the maximum percentage (97%) of deaths attributable to influenza in people older than 64 years with respect to the mortality total associated with influenza (13,822 deaths). The rate of excess mortality due to influenza and pneumonia and respiratory causes in people older than 64 years, obtained by the Serfling model, also reached a peak in the 2011-2012 season: 18.07 and 77.20, deaths per 100,000 inhabitants, respectively. A significant increase in mortality in elderly people in Spain was detected by the Spanish daily mortality surveillance system and by the European mortality surveillance system in the winter of 2012, coinciding with a late influenza season, with a predominance of the A(H3N2) virus, and a cold wave in Spain. This study suggests that influenza could have been one of the main factors contributing to the mortality excess

  18. Global Warming: Physics and Facts

    Energy Technology Data Exchange (ETDEWEB)

    Levi, B.G. [Physics Today, New York, NY (United States); Hafemeister, D. [Committee on Foreign Relations (U.S. Senate), Washington, DC (United States); Scribner, R. [Georgetown Univ., Washington, DC (United States)] [eds.

    1992-05-01

    This report contains papers on: A tutorial on global atmospheric energetics and the greenhouse effect; global climate models: what and how; comparison of general circulation models; climate and the earth`s radiation budget; temperature and sea level change; short-term climate variability and predictions; the great ocean conveyor; trace gases in the atmosphere: temporal and spatial trends; the geochemical carbon cycle and the uptake of fossil fuel CO{sub 2}; forestry and global warming; the physical and policy linkages; policy implications of greenhouse warming; options for lowering US carbon dioxide emissions; options for reducing carbon dioxide emissions; and science and diplomacy: a new partnership to protect the environment.

  19. Global Warming: Physics and Facts

    Energy Technology Data Exchange (ETDEWEB)

    Levi, B.G. (Physics Today, New York, NY (United States)); Hafemeister, D. (Committee on Foreign Relations (U.S. Senate), Washington, DC (United States)); Scribner, R. (Georgetown Univ., Washington, DC (United States)) (eds.)

    1992-01-01

    This report contains papers on: A tutorial on global atmospheric energetics and the greenhouse effect; global climate models: what and how; comparison of general circulation models; climate and the earth's radiation budget; temperature and sea level change; short-term climate variability and predictions; the great ocean conveyor; trace gases in the atmosphere: temporal and spatial trends; the geochemical carbon cycle and the uptake of fossil fuel CO{sub 2}; forestry and global warming; the physical and policy linkages; policy implications of greenhouse warming; options for lowering US carbon dioxide emissions; options for reducing carbon dioxide emissions; and science and diplomacy: a new partnership to protect the environment.

  20. Issues concerning global warming today

    Institute of Scientific and Technical Information of China (English)

    Zhenqiu REN

    2008-01-01

    The global weather of today is growing significantly warmer; this is an indisputable fact.However,the scientific community has not yet reached consensus on the causes of global warming and its possible consequences.This paper introduces the causes of global warming and summarizes its results,which both involve a series of huge and complex system issues.Our top priority is to pinpoint the main reason and the interrelated links between causative factors by adopting a macro-approach,or comprehensive comparison analysis.Its physical mechanism was then determined and its digital model established after quantitative study.

  1. Global warming at the summit

    Science.gov (United States)

    Showstack, Randy

    During the recent summit meeting between Russian President Vladimir Putin and U.S. President Bill Clinton, the two leaders reaffirmed their concerns about global warming and the need to continue to take actions to try to reduce the threat.In a June 4 joint statement, they stressed the need to develop flexibility mechanisms, including international emissions trading, under the Kyoto Protocol to the United Nations Framework Convention on Climate Change. They also noted that initiatives to reduce the risk of greenhouse warming, including specific mechanisms of the Kyoto Protocol, could potentially promote economic growth.

  2. Seasonal Variation in Epidemiology

    Science.gov (United States)

    Marrero, Osvaldo

    2013-01-01

    Seasonality analyses are important in medical research. If the incidence of a disease shows a seasonal pattern, then an environmental factor must be considered in its etiology. We discuss a method for the simultaneous analysis of seasonal variation in multiple groups. The nuts and bolts are explained using simple trigonometry, an elementary…

  3. Personal, Seasonal Suns

    Science.gov (United States)

    Sutley, Jane

    2010-01-01

    This article presents an art project designed for upper-elementary students to (1) imagine visual differences in the sun's appearance during the four seasons; (2) develop ideas for visually translating their personal experiences regarding the seasons to their sun drawings; (3) create four distinctive seasonal suns using colors and imagery to…

  4. Adaptation to seasonality and the winter freeze

    Directory of Open Access Journals (Sweden)

    Jill Christine Preston

    2013-06-01

    Full Text Available Flowering plants initially diversified during the Mesozoic era at least 140 million years ago in regions of the world where temperate seasonal environments were not encountered. Since then several cooling events resulted in the contraction of warm and wet environments and the establishment of novel temperate zones in both hemispheres. In response, less than half of modern angiosperm families have members that evolved specific adaptations to cold seasonal climates, including cold acclimation, freezing tolerance, endodormancy, and vernalization responsiveness. Despite compelling evidence for multiple independent origins, the level of genetic constraint on the evolution of adaptations to seasonal cold is not well understood. However, the recent increase in molecular genetic studies examining the response of model and crop species to seasonal cold offers new insight into the evolutionary lability of these traits. This insight has major implications for our understanding of complex trait evolution, and the potential role of local adaptation in response to past and future climate change. In this review, we discuss the biochemical, morphological, and developmental basis of adaptations to seasonal cold, and synthesize recent literature on the genetic basis of these traits in a phylogenomic context. We find evidence for multiple genetic links between distinct physiological responses to cold, possibly reinforcing the coordinated expression of these traits. Furthermore, repeated recruitment of the same or similar ancestral pathways suggests that land plants might be somewhat pre-adapted to dealing with temperature stress, perhaps making inducible cold traits relatively easy to evolve.

  5. Interannual variation in rainfall, drought stress and seedling mortality may mediate monodominance in tropical flooded forests.

    Science.gov (United States)

    Lopez, Omar R; Kursar, Thomas A

    2007-11-01

    Flood tolerance is commonly regarded as the main factor explaining low diversity and monodominance in tropical swamps. In this study we examined seedling mortality in relation to seasonality, i.e., flooding versus drought, of the dominant tree species (Prioria copaifera), and three associated species (Pterocarpus officinalis, Carapa guianensis and Pentaclethra macroloba), in seasonally flooded forests (SFF) in Darien, Panama. Seedling mortality differed among species, years and seasons. Prioria seedlings experienced the lowest overall mortality, and after 3 years many more Prioria seedlings remained alive than those of any of the associated species. In general, within species, larger seedlings had greater survival. Seed size, which can vary by close to 2 orders of magnitude in Prioria, had a confounding effect with that of topography. Large-seeded Prioria seedlings experienced 1.5 times greater mortality than small-seeded seedlings, as large-seeded Prioria seedlings were more likely to be located in depressions. This finding suggests that seed size, plant size and topography are important in understanding SFF regeneration. For all species, seedling mortality was consistently greater during the dry season than during flooding. For Prioria, dry season seedling mortality was correlated with drought stress, that is, high mortality during the long El Niño dry season of 1998 and the normal dry season of 2000, but very low dry season mortality during the mild dry season of 1999. Prioria's ability to dominate in seasonally flooded forest of Central America is partly explained by its low drought-related mortality in comparison to associated species.

  6. A zero-power warming chamber for investigating plant responses to rising temperature

    Directory of Open Access Journals (Sweden)

    K. F. Lewin

    2017-09-01

    Full Text Available Advances in understanding and model representation of plant and ecosystem responses to rising temperature have typically required temperature manipulation of research plots, particularly when considering warming scenarios that exceed current climate envelopes. In remote or logistically challenging locations, passive warming using solar radiation is often the only viable approach for temperature manipulation. However, current passive warming approaches are only able to elevate the mean daily air temperature by  ∼  1.5 °C. Motivated by our need to understand temperature acclimation in the Arctic, where warming has been markedly greater than the global average and where future warming is projected to be  ∼  2–3 °C by the middle of the century; we have developed an alternative approach to passive warming. Our zero-power warming (ZPW chamber requires no electrical power for fully autonomous operation. It uses a novel system of internal and external heat exchangers that allow differential actuation of pistons in coupled cylinders to control chamber venting. This enables the ZPW chamber venting to respond to the difference between the external and internal air temperatures, thereby increasing the potential for warming and eliminating the risk of overheating. During the thaw season on the coastal tundra of northern Alaska our ZPW chamber was able to elevate the mean daily air temperature 2.6 °C above ambient, double the warming achieved by an adjacent passively warmed control chamber that lacked our hydraulic system. We describe the construction, evaluation and performance of our ZPW chamber and discuss the impact of potential artefacts associated with the design and its operation on the Arctic tundra. The approach we describe is highly flexible and tunable, enabling customization for use in many different environments where significantly greater temperature manipulation than that possible with existing passive warming

  7. Challenge of Fetal Mortality

    Science.gov (United States)

    ... Reports from the National Medical Care Utilization and Expenditure Survey Clearinghouse on Health Indexes Statistical Notes for ... Fetal mortality is a major, but often overlooked, public health problem. Fetal mortality refers to spontaneous intrauterine ...

  8. A remarkable climate warming hiatus over Northeast China since 1998

    Science.gov (United States)

    Sun, Xiubao; Ren, Guoyu; Ren, Yuyu; Fang, Yihe; Liu, Yulian; Xue, Xiaoying; Zhang, Panfeng

    2017-07-01

    Characteristics and causes of global warming hiatus (GWH) phenomenon have received much attention in recent years. Monthly mean data of land surface air maximum temperature (Tmax), minimum temperature (Tmin), and mean temperature (Tmean) of 118 national stations since 1951 in Northeast China are used in this paper to analyze the changes of land surface air temperature in recent 64 years with an emphasis on the GWH period. The results show that (1) from 1951 to 2014, the warming trends of Tmax, Tmin, and Tmean are 0.20, 0.42, and 0.34 °C/decade respectively for the whole area, with the warming rate of Tmin about two times of Tmax, and the upward trend of Tmean obviously higher than mainland China and global averages; (2) in the period 1998-2014, the annual mean temperature consistently exhibits a cooling phenomenon in Northeast China, and the trends of Tmax, Tmin, and Tmean are -0.36, -0.14, and -0.28 °C/decade respectively; (3) in the GWH period, seasonal mean cooling mainly occurs in northern winter (DJF) and spring (MAM), but northern summer (JJA) and autumn (SON) still experience a warming, implying that the annual mean temperature decrease is controlled by the remarkable cooling of winter and spring; (4) compared to the global and mainland China averages, the hiatus phenomenon is more evident in Northeast China, and the cooling trends are more obvious in the cold season; (5) the Northeast China cooling trend occurs under the circulation background of the negative phase Arctic Oscillation (AO), and it is also closely related to strengthening of the Siberia High (SH) and the East Asian Trough (EAT), and the stronger East Asian winter monsoon (EAWM) over the GWH period.

  9. Fourfold higher tundra volatile emissions due to arctic summer warming

    Science.gov (United States)

    Lindwall, Frida; Schollert, Michelle; Michelsen, Anders; Blok, Daan; Rinnan, Riikka

    2016-03-01

    Biogenic volatile organic compounds (BVOCs), which are mainly emitted by vegetation, may create either positive or negative climate forcing feedbacks. In the Subarctic, BVOC emissions are highly responsive to temperature, but the effects of climatic warming on BVOC emissions have not been assessed in more extreme arctic ecosystems. The Arctic undergoes rapid climate change, with air temperatures increasing at twice the rate of the global mean. Also, the amount of winter precipitation is projected to increase in large areas of the Arctic, and it is unknown how winter snow depth affects BVOC emissions during summer. Here we examine the responses of BVOC emissions to experimental summer warming and winter snow addition—each treatment alone and in combination—in an arctic heath during two growing seasons. We observed a 280% increase relative to ambient in BVOC emissions in response to a 4°C summer warming. Snow addition had minor effects on growing season BVOC emissions after one winter but decreased BVOC emissions after the second winter. We also examined differences between canopy and air temperatures and found that the tundra canopy surface was on average 7.7°C and maximum 21.6°C warmer than air. This large difference suggests that the tundra surface temperature is an important driver for emissions of BVOCs, which are temperature dependent. Our results demonstrate a strong response of BVOC emissions to increasing temperatures in the Arctic, suggesting that emission rates will increase with climate warming and thereby feed back to regional climate change.

  10. Impacts of +2 °C global warming on winter tourism demand in Europe

    NARCIS (Netherlands)

    Damm, Andrea; Greuell, Wouter; Landgren, Oskar; Prettenthaler, Franz

    2017-01-01

    Increasing temperatures and snow scarce winter seasons challenge the winter tourism industry. In this study the impacts of +2 °C global warming on winter tourism demand in Europe's ski tourism related NUTS-3 regions are quantified. Using time series regression models, the relationship between

  11. Microclimate impacts of passive warming methods in Antarctica: implications for climate change studies

    NARCIS (Netherlands)

    Bokhorst, S.; Huiskes, A.H.L.; Convey, P.; Sinclair, B.J.; Lebouvier, M.; van de Vijver, B.; Wall, D.H.

    2011-01-01

    Passive chambers are used to examine the impacts of summer warming in Antarctica but, so far, impacts occurring outside the growing season, or related to extreme temperatures, have not been reported, despite their potentially large biological significance. In this review, we synthesise and discuss t

  12. Medieval Warm Period Archives Preserved in Limpet Shells (Patella Vulgata) From Viking Deposits, United Kingdom

    Science.gov (United States)

    Mobilia, M.; Surge, D.

    2008-12-01

    The Medieval Warm Period (700-1100 YBP) represents a recent period of warm climate, and as such provides a powerful comparison to today's continuing warming trend. However, the spatial and temporal variability inherent in the Medieval Warm Period (MWP) makes it difficult to differentiate between global climate trends and regional variability. The continued study of this period will allow for the better understanding of temperature variability, both regional and global, during this climate interval. Our study is located in the Orkney Islands, Scotland, which is a critical area to understand climate dynamics. The North Atlantic Oscillation and Gulf Stream heavily influence climate in this region, and the study of climate intervals during the MWP will improve our understanding of the behavior of these climate mechanisms during this interval. Furthermore, the vast majority of the climate archive has been derived from either deep marine or arctic environments. Studying a coastal environment will offer valuable insight into the behavior of maritime climate during the MWP. Estimated seasonal sea surface temperature data were derived through isotopic analysis of limpet shells (Patella vulgata). Analysis of modern shells confirms that growth temperature tracks seasonal variation in ambient water temperature. Preliminary data from MWP shells record a seasonal temperature range comparable to that observed in the modern temperature data. We will extend the range of temperature data from the 10th through 14th centuries to advance our knowledge of seasonal temperature variability during the late Holocene.

  13. Excess mortality in hyperthyroidism

    DEFF Research Database (Denmark)

    Hjelm Brandt Kristensen, Frans; Pedersen, Dorthe Almind; Christensen, Kaare

    2012-01-01

    Hyperthyroidism is associated with severe comorbidity, such as stroke, and seems to confer increased mortality. However, it is unknown whether this increased mortality is explained by hyperthyroidism per se, comorbidity, and/or genetic confounding.......Hyperthyroidism is associated with severe comorbidity, such as stroke, and seems to confer increased mortality. However, it is unknown whether this increased mortality is explained by hyperthyroidism per se, comorbidity, and/or genetic confounding....

  14. Health effects of global warming: Problems in assessment

    Energy Technology Data Exchange (ETDEWEB)

    Longstreth, J.

    1993-06-01

    Global warming is likely to result in a variety of environmental effects ranging from impacts on species diversity, changes in population size in flora and fauna, increases in sea level and possible impacts on the primary productivity of the sea. Potential impacts on human health and welfare have included possible increases in heat related mortality, changes in the distribution of disease vectors, and possible impacts on respiratory diseases including hayfever and asthma. Most of the focus thus far is on effects which are directly related to increases in temperature, e.g., heat stress or perhaps one step removed, e.g., changes in vector distribution. Some of the more severe impacts are likely to be much less direct, e.g., increases in migration due to agricultural failure following prolonged droughts. This paper discusses two possible approaches to the study of these less-direct impacts of global warming and presents information from on-going research using each of these approaches.

  15. Changes in winter warming events in the Nordic Arctic Region

    Science.gov (United States)

    Vikhamar-Schuler, Dagrun; Isaksen, Ketil; Haugen, Jan Erik; Bjerke, Jarle Werner; Tømmervik, Hans

    2015-04-01

    In recent years winter warming events are frequently reported from Arctic areas. Extraordinarily warm weather episodes, occasionally combined with intense rainfall, cause severe ecological disturbance and great challenges for Arctic infrastructure. For example, the formation of ground ice due to winter rain or melting prevents reindeer from grazing, leads to vegetation browning, and impacts soil temperatures. The infrastructure may be affected by avalanches and floods resulting from intense snowmelt. The aim of our analysis is to study changes in warm spells during winter in the Nordic Arctic Region, here defined as the regions in Norway, Sweden and Finland north of the Arctic circle (66.5°N), including the Arctic islands Svalbard and Jan Mayen. Within this study area we have selected the longest available high quality observation series with daily temperature and precipitation. For studying future climate we use available regionally downscaled scenarios. We analyse three time periods: 1) the past 50-100 years, 2) the present (last 15 years, 2000-2014) and 3) the future (next 50-100 years). We define an extended winter season (October-April) and further divide it into three subseasons: 1) Early winter (October and November), 2) Mid-winter (December, January and February) and 3) Late-winter (March and April). We identify warm spells using two different classification criteria: a) days with temperature above 0°C (the melting temperature); and b) days with temperature in excess of the 90th percentile of the 1985-2014 temperature for each subseason. Both wet and dry warm spells are analysed. We compare the results for the mainland stations (maritime and inland stations) with the Arctic islands. All stations have very high frequency of warm weather events in the period 1930-1940s and for the last 15 years (2000-2014). For the most recent period the largest increase in number of warm spells are observed at the northernmost stations. We also find a continuation of this

  16. On tropical cyclone frequency and the warm pool area

    Directory of Open Access Journals (Sweden)

    R. E. Benestad

    2009-04-01

    Full Text Available The proposition that the rate of tropical cyclogenesis increases with the size of the "warm pool" is tested by comparing the seasonal variation of the warm pool area with the seasonality of the number of tropical cyclones. An analysis based on empirical data from the Northern Hemisphere is presented, where the warm pool associated with tropical cyclone activity is defined as the area, A, enclosed by the 26.5°C SST isotherm. Similar analysis was applied to the temperature weighted area AT with similar results.

    An intriguing non-linear relationship of high statistical significance was found between the temperature weighted area in the North Atlantic and the North-West Pacific on the one hand and the number of cyclones, N, in the same ocean basin on the other, but this pattern was not found over the North Indian Ocean. A simple statistical model was developed, based on the historical relationship between N and A. The simple model was then validated against independent inter-annual variations in the seasonal cyclone counts in the North Atlantic, but the correlation was not statistically significant in the North-West Pacific. No correlation, however, was found between N and A in the North Indian Ocean.

    A non-linear relationship between the cyclone number and temperature weighted area may in some ocean basins explain both why there has not been any linear trend in the number of cyclones over time as well as the recent upturn in the number of Atlantic hurricanes. The results also suggest that the notion of the number of tropical cyclones being insensitive to the area A is a misconception.

  17. Occupational Mortality, Background on

    DEFF Research Database (Denmark)

    Lynge, Elsebeth

    2016-01-01

    The study of occupational mortality involves the systematic tabulation of mortality by occupational or socioeconomic groups. Three main methods are used to conduct these studies: cross-sectional studies, death certificate studies, and follow-up studies. Cross-sectional studies were undertaken in ...... the mortality rates of blue- and white-collar workers....

  18. GLOBAL WARMING: A NEW PERSPECTIVE

    Energy Technology Data Exchange (ETDEWEB)

    Ritesh Arya [Arya Drillers, 405, GH7A, Sector 20, Panchkula, Haryana (India)

    2008-09-30

    A lot has been said about global warming, various models projected and debated to show its importance in the present day. All these have actually made the issue more complex and confusing. Present paper is based on the observations made by the author during the drilling operations for providing sustainable water solutions based on developing groundwater resources in the various hydrostraigraphic zones identified by Arya,(1996) for the last 15 years in Himachal Pradesh and the high altitude, cold mountain, deserts of Ladakh in NW Indian Himalayas. The author tends to redefine global warming as phenomenon for transporting the weathered and eroded material which had been accumulated during the global cooling phase in the past. The agents can be biotic (man and living organisms) and abiotic (geological, geomorphologic, climatologic, planetary). The author also tends to introduce a biogeologic cycle which will explain in a very simple way the relevance of global warming in shaping the earth now and in future. The paper also discuses the fact that no phenomenon can be understood in isolation and the history and its cycle has to be understood to enjoy the concept in totality. Present paper will focus on these issues and try to touch the genesis of the problem in a very simple but scientific manner. Last but not the least the paper will end with an optimistic note ''Global warming is natural, Enjoy it''.

  19. Acid Rain Limits Global Warming

    Institute of Scientific and Technical Information of China (English)

    Will Knight; 张林玲

    2004-01-01

    @@ Acid rain restricts global warming by reducing methane① emissions from natural wetland areas, suggests a global climate study. Acid rain is the result of industrial pollution,which causes rainwater to carry small quantities of acidic compoumds② such as sulphuric and nitric acid③. Contaminated rainwater can upset rivers and lakes, killing fish and other organisms and also damage plants, trees and buildings.

  20. Plant movements and climate warming

    DEFF Research Database (Denmark)

    De Frenne, Pieter; Coomes, David A.; De Schrijver, An

    2014-01-01

    •Most range shift predictions focus on the dispersal phase of the colonization process. Because moving populations experience increasingly dissimilar nonclimatic environmental conditions as they track climate warming, it is also critical to test how individuals originating from contrasting therma...

  1. Shifting grassland plant community structure drives positive interactive effects of warming and diversity on aboveground net primary productivity.

    Science.gov (United States)

    Cowles, Jane M; Wragg, Peter D; Wright, Alexandra J; Powers, Jennifer S; Tilman, David

    2016-02-01

    Ecosystems worldwide are increasingly impacted by multiple drivers of environmental change, including climate warming and loss of biodiversity. We show, using a long-term factorial experiment, that plant diversity loss alters the effects of warming on productivity. Aboveground primary productivity was increased by both high plant diversity and warming, and, in concert, warming (≈1.5 °C average above and belowground warming over the growing season) and diversity caused a greater than additive increase in aboveground productivity. The aboveground warming effects increased over time, particularly at higher levels of diversity, perhaps because of warming-induced increases in legume and C4 bunch grass abundances, and facilitative feedbacks of these species on productivity. Moreover, higher plant diversity was associated with the amelioration of warming-induced environmental conditions. This led to cooler temperatures, decreased vapor pressure deficit, and increased surface soil moisture in higher diversity communities. Root biomass (0-30 cm) was likewise consistently greater at higher plant diversity and was greater with warming in monocultures and at intermediate diversity, but at high diversity warming had no detectable effect. This may be because warming increased the abundance of legumes, which have lower root : shoot ratios than the other types of plants. In addition, legumes increase soil nitrogen (N) supply, which could make N less limiting to other species and potentially decrease their investment in roots. The negative warming × diversity interaction on root mass led to an overall negative interactive effect of these two global change factors on the sum of above and belowground biomass, and thus likely on total plant carbon stores. In total, plant diversity increased the effect of warming on aboveground net productivity and moderated the effect on root mass. These divergent effects suggest that warming and changes in plant diversity are likely to have both

  2. Tree mortality predicted from drought-induced vascular damage

    Science.gov (United States)

    Anderegg, William R. L.; Flint, Alan L.; Huang, Cho-ying; Flint, Lorraine E.; Berry, Joseph A.; Davis, Frank W.; Sperry, John S.; Field, Christopher B.

    2015-01-01

    The projected responses of forest ecosystems to warming and drying associated with twenty-first-century climate change vary widely from resiliency to widespread tree mortality1, 2, 3. Current vegetation models lack the ability to account for mortality of overstorey trees during extreme drought owing to uncertainties in mechanisms and thresholds causing mortality4, 5. Here we assess the causes of tree mortality, using field measurements of branch hydraulic conductivity during ongoing mortality in Populus tremuloides in the southwestern United States and a detailed plant hydraulics model. We identify a lethal plant water stress threshold that corresponds with a loss of vascular transport capacity from air entry into the xylem. We then use this hydraulic-based threshold to simulate forest dieback during historical drought, and compare predictions against three independent mortality data sets. The hydraulic threshold predicted with 75% accuracy regional patterns of tree mortality as found in field plots and mortality maps derived from Landsat imagery. In a high-emissions scenario, climate models project that drought stress will exceed the observed mortality threshold in the southwestern United States by the 2050s. Our approach provides a powerful and tractable way of incorporating tree mortality into vegetation models to resolve uncertainty over the fate of forest ecosystems in a changing climate.

  3. Photosynthetic and Respiratory Acclimation to Experimental Warming for Four Species in a Tallgrass Prairie Ecosystem

    Institute of Scientific and Technical Information of China (English)

    Xuhui Zhou; Xiaozhong Liu; Linda L. Wallace; Yiqi Luo

    2007-01-01

    Global temperature has been increased by 0.6 ℃ over the past century and is predicted to increase by 1.4-5.8 ℃ by the end of this century. It is unclear what impacts global warming will have on tallgrass species. In the present study, we examined leaf net photosynthetic rate (Pn) and leaf respiration rate in darkness (Rd) of Aster ericoides (L.)Nesom, Ambrosia psilostachya DC., Hellanthus mollis Lam., and Sorghastrum nutans (L.) Nash In response to experimental warming in a tallgrass prairie ecosystem of the Great Plains, USA, in the autumn (fall) of 2000 and through 2001. Warming has been implemented with infrared heaters since 21 November 1999. The Pn increased significantly in spring, decreased in early fall, and did not change in summer and late fall in the four species under warming compared with control. The Rd of the four species increased significantly until mid-summer and then did not change under warming. Measured temperature-response curves of Pn showed that warming increased the optimum temperature of Pn (Topt) by 2.32 and 4.59 ℃ for H. mollis and S. nutans, respectively, in August, whereas there were no changes in May and September, and A. ericoides and A. psilostachya also showed no changes in any of the 3 months. However, Pn at optimum temperature (Popt) showed downregulation in September and no regulation in May and August for all four species. The temperature-response curves of Rd illustrate that the temperature sensitivity of Rd, Q10, was lower in the warmed plots compared with the control plots, except for A. ericoides in August, whereas there were no changes in May and September for all four species. The results of the present study indicate that photosynthetic and respiratory acclimation varies with species and among seasons, occurring in the mid-growing season and not in the early and late growing seasons.

  4. Phenomenological theory of mortality

    Science.gov (United States)

    Azbel, Mark Ya.

    1997-09-01

    Extensive demographic studies relate aging to the increase in mortality, terminated by the species-specific lifespan limit. Meanwhile, recent experiments demonstrate that medfly mortality decreases at older ages, and challenge a limited lifespan paradigm. This paper proves that there exists a genetically programmed probability to die at any given age, and presents its phenomenological theory. The implications of the universal mortality law crucially depend on the cohort heterogeneity. For relatively high heterogeneity the law predicts unitarily vanishing old age mortality; this is verified with medfly data. For relatively low heterogeneity it predicts a precipitous drop in mortality fluctuations in old age. This is verified with demographic data. If comprehensive studies verify a species-specific characteristic age, then that age may be genetically manipulated. If the studies verify a unitary law of mortality, the results may be generalized to all species. A phenomenological model of mortality is presented.

  5. WRF-Chem simulation of aerosol seasonal variability in the San Joaquin Valley

    Science.gov (United States)

    Wu, Longtao; Su, Hui; Kalashnikova, Olga V.; Jiang, Jonathan H.; Zhao, Chun; Garay, Michael J.; Campbell, James R.; Yu, Nanpeng

    2017-06-01

    WRF-Chem simulations of aerosol seasonal variability in the San Joaquin Valley (SJV), California, are evaluated by satellite and in situ observations. Results show that the WRF-Chem model successfully captures the distribution and magnitude of and variation in SJV aerosols during the cold season. However, aerosols are not well represented in the warm season. Aerosol simulations in urban areas during the cold season are sensitive to model horizontal resolution, with better simulations at 4 km resolution than at 20 km resolution, mainly due to inhomogeneous distribution of anthropogenic emissions and precipitation that is represented better in the 4 km simulation. In rural areas, the model sensitivity to grid size is rather small. Our observational analysis reveals that dust is a primary contributor to aerosols in the SJV, especially during the warm season. Aerosol simulations in the warm season are sensitive to the parameterization of dust emission in WRF-Chem. The GOCART (Goddard Global Ozone Chemistry Aerosol Radiation and Transport) dust scheme produces very little dust in the SJV, while the DUSTRAN (DUST TRANsport model) scheme overestimates dust emission. Vertical mixing of aerosols is not adequately represented in the model based on CALIPSO (Cloud-Aerosol Lidar and Infrared pathfinder Satellite Observation) aerosol extinction profiles. Improved representation of dust emission and vertical mixing in the boundary layer is needed for better simulations of aerosols during the warm season in the SJV.

  6. Drilling comparison in "warm ice" and drill design comparison

    DEFF Research Database (Denmark)

    Augustin, L.; Motoyama, H.; Wilhelms, F.

    2007-01-01

    at each site, the drilling rate dropped and the drilling teams had to deal with refrozen ice on cutters and drill heads. Drills have different limits and perform differently. In this comparative study, we examine depth, pressure, temperature, pump flow and cutting speed. Finally, we compare a few......For the deep ice-core drilling community, the 2005/06 Antarctic season was an exciting and fruitful one. In three different Antarctic locations, Dome Fuji, EPICA DML and Vostok, deep drillings approached bedrock (the ice-water interface in the case of Vostok), emulating what had previously been...... achieved at NorthGRIP, Greenland, (summer 2003 and 2004) and at EPICA Dome C2, Antarctica (season 2004/05). For the first time in ice-core drilling history, three different types of drill (KEMS, JARE and EPICA) simultaneously reached the depth of 'warm ice' under high pressure. After excellent progress...

  7. Possible Origins of the Western Pacific Warm Pool Decadal Variability

    Institute of Scientific and Technical Information of China (English)

    GAN Bolan; WU Lixin

    2012-01-01

    In this study,the impacts of the Pacific Decadal Oscillation (PDO) and the Atlantic Multidecadal Oscillation (AMO) on the western Pacific warm pool (WPWP) were investigated.Our results show that the WPWP is linked with the PDO and the AMO at multiple time scales.On the seasonal time scales,the WPWP and the PDO/AMO reinforce each other,while at decadal time scales the forcing roles of the PDO and the AMO dominate.Notably,a positive PDO tends to enlarge the WPWP at both seasonal and decadal time scales,while a positive AMO tends to reduce the WPWP at decadal time scales.Furthermore,the decadal variability of the WPWP can be well predicted based on the PDO and AMO.

  8. Lungs in a warming world: climate change and respiratory health.

    Science.gov (United States)

    Bernstein, Aaron S; Rice, Mary B

    2013-05-01

    Climate change is a health threat no less consequential than cigarette smoking. Increased concentrations of greenhouse gases, and especially CO₂, in the earth's atmosphere have already warmed the planet substantially, causing more severe and prolonged heat waves, temperature variability, air pollution, forest fires, droughts, and floods, all of which put respiratory health at risk. These changes in climate and air quality substantially increase respiratory morbidity and mortality for patients with common chronic lung diseases such as asthma and COPD and other serious lung diseases. Physicians have a vital role in addressing climate change, just as they did with tobacco, by communicating how climate change is a serious, but remediable, hazard to their patients.

  9. Global warming: Clouds cooled the Earth

    Science.gov (United States)

    Mauritsen, Thorsten

    2016-12-01

    The slow instrumental-record warming is consistent with lower-end climate sensitivity. Simulations and observations now show that changing sea surface temperature patterns could have affected cloudiness and thereby dampened the warming.

  10. Arctic climate change: Greenhouse warming unleashed

    Science.gov (United States)

    Mauritsen, Thorsten

    2016-04-01

    Human activity alters the atmospheric composition, which leads to global warming. Model simulations suggest that reductions in emission of sulfur dioxide from Europe since the 1970s could have unveiled rapid Arctic greenhouse gas warming.

  11. Occurrence of suicide and seasonal variation

    Directory of Open Access Journals (Sweden)

    Retamal C. Pedro

    1998-01-01

    Full Text Available OBJECTIVE: To review the estimated suicide rates for the Region Metropolitan, the main socio-political center in Chile, for the period 1979-1994, and to determine whether they follow a seasonal pattern. METHOD: Data available for the period 1979-94 at the Forensic Services in Chile was analyzed using ANOVA. RESULTS: It was register 5.386 suicides. While the "warm" months (October, November, December & January concentrated 39.0% of cases, the so called "cold" months reported 28,7%. This contrast is made even clearer by the month-to-month analysis, showing the highest suicide rate in December (10.9% against the lowest rate in June (7.0%. Further statistical analysis revealed these differences to be significant. CONCLUSION: The study shows that in Chile, representing as it does the Southern Hemisphere, the suicide rates tend to present a seasonal variation as has elsewhere been determined for in the North Hemisphere.

  12. Exceptional warming in the Western Pacific-Indian Ocean warm pool has contributed to more frequent droughts in eastern Africa

    Science.gov (United States)

    Funk, Christopher C.; Peterson, Thomas C.; Stott, Peter A.; Herring, Stephanie

    2012-01-01

    In 2011, East Africa faced a tragic food crisis that led to famine conditions in parts of Somalia and severe food shortages in parts of Ethiopia and Somalia. While many nonclimatic factors contributed to this crisis (high global food prices, political instability, and chronic poverty, among others) failed rains in both the boreal winter of 2010/11 and the boreal spring of 2011 played a critical role. The back-to-back failures of these rains, which were linked to the dominant La Niña climate and warm SSTs in the central and southeastern Indian Ocean, were particularly problematic since they followed poor rainfall during the spring and summer of 2008 and 2009. In fact, in parts of East Africa, in recent years, there has been a substantial increase in the number of below-normal rainy seasons, which may be related to the warming of the western Pacific and Indian Oceans (for more details, see Funk et al. 2008; Williams and Funk 2011; Williams et al. 2011; Lyon and DeWitt 2012). The basic argument of this work is that recent warming in the Indian–Pacific warm pool (IPWP) enhances the export of geopotential height energy from the warm pool, which tends to produce subsidence across eastern Africa and reduce onshore moisture transports. The general pattern of this disruption has been supported by canonical correlation analyzes and numerical experiments with the Community Atmosphere Model (Funk et al. 2008), diagnostic evaluations of reanalysis data (Williams and Funk 2011; Williams et al. 2011), and SST-driven experiments with ECHAM4.5, ECHAM5, and the Community Climate Model version 3 (CCM3.6) (Lyon and DeWitt 2012).

  13. Elevational differences in developmental plasticity determine phenological responses of grasshoppers to recent climate warming.

    Science.gov (United States)

    Buckley, Lauren B; Nufio, César R; Kirk, Evan M; Kingsolver, Joel G

    2015-06-22

    Annual species may increase reproduction by increasing adult body size through extended development, but risk being unable to complete development in seasonally limited environments. Synthetic reviews indicate that most, but not all, species have responded to recent climate warming by advancing the seasonal timing of adult emergence or reproduction. Here, we show that 50 years of climate change have delayed development in high-elevation, season-limited grasshopper populations, but advanced development in populations at lower elevations. Developmental delays are most pronounced for early-season species, which might benefit most from delaying development when released from seasonal time constraints. Rearing experiments confirm that population, elevation and temperature interact to determine development time. Population differences in developmental plasticity may account for variability in phenological shifts among adults. An integrated consideration of the full life cycle that considers local adaptation and plasticity may be essential for understanding and predicting responses to climate change.

  14. Elevational differences in developmental plasticity determine phenological responses of grasshoppers to recent climate warming

    Science.gov (United States)

    Buckley, Lauren B.; Nufio, César R.; Kirk, Evan M.; Kingsolver, Joel G.

    2015-01-01

    Annual species may increase reproduction by increasing adult body size through extended development, but risk being unable to complete development in seasonally limited environments. Synthetic reviews indicate that most, but not all, species have responded to recent climate warming by advancing the seasonal timing of adult emergence or reproduction. Here, we show that 50 years of climate change have delayed development in high-elevation, season-limited grasshopper populations, but advanced development in populations at lower elevations. Developmental delays are most pronounced for early-season species, which might benefit most from delaying development when released from seasonal time constraints. Rearing experiments confirm that population, elevation and temperature interact to determine development time. Population differences in developmental plasticity may account for variability in phenological shifts among adults. An integrated consideration of the full life cycle that considers local adaptation and plasticity may be essential for understanding and predicting responses to climate change. PMID:26041342

  15. Persistent influence of tropical North Atlantic wintertime sea surface temperature on the subsequent Atlantic hurricane season

    Science.gov (United States)

    Wang, Xidong; Liu, Hailong; Foltz, Gregory R.

    2017-08-01

    This study explores the seasonally lagged impact of wintertime sea surface temperature (SST) in the Atlantic main development region (MDR) on the subsequent Atlantic hurricane season. It is found that wintertime SST anomalies in the MDR can persist into the summer, explaining 42% of the variance in the subsequent hurricane season's SST during 1951-2010. An anomalously warm wintertime in the MDR is usually followed by an anomalously active hurricane season. Analysis shows an important constraint on the seasonal evolution of the MDR SST by the water vapor feedback process, in addition to the well-known wind-evaporation-SST and cloud-SST feedback mechanisms over the tropical North Atlantic. The water vapor feedback influences the seasonal evolution of MDR SST by modulating seasonal variations of downward longwave radiation. This wintertime thermal control of hurricane activity has significant implications for seasonal predictions and long-term projections of hurricane activity over the North Atlantic.

  16. Hydrological consequences of global warming

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Norman L.

    2009-06-01

    The 2007 Intergovernmental Panel for Climate Change indicates there is strong evidence that the atmospheric concentration of carbon dioxide far exceeds the natural range over the last 650,000 years, and this recent warming of the climate system is unequivocal, resulting in more frequent extreme precipitation events, earlier snowmelt runoff, increased winter flood likelihoods, increased and widespread melting of snow and ice, longer and more widespread droughts, and rising sea level. The effects of recent warming has been well documented and climate model projections indicate a range of hydrological impacts with likely to very likely probabilities (67 to 99 percent) of occurring with significant to severe consequences in response to a warmer lower atmosphere with an accelerating hydrologic cycle.

  17. Global Warming and Financial Umbrellas

    Energy Technology Data Exchange (ETDEWEB)

    Dosi, C.; Moretto, M. [Department of Economics, University of Padova, Padova (Italy)

    2001-10-01

    A new instrument for hedging weather risks has made its appearance in the financial arena. Trade in 'weather derivatives' has taken off in the US, and interest is growing elsewhere. Whilst such contracts may be simply interpreted as a new tool for solving a historical problem, the question addressed in this paper is if, besides other factors, the appearance of weather derivatives is somehow related to anthropogenic climate change. Our tentative answer is positive. Since 'global warming' does not simply mean an increase in averaged temperatures, but increased climate variability, and increased frequency and magnitude of weather extremes, derivative contracts may potentially become a useful tool for hedging some weather risks, insofar as they may provide coverage at a lower cost than standard insurance schemes. Keywords: Global warming, climate variability, insurance coverage, weather derivatives.

  18. MCCB warm adjustment testing concept

    Science.gov (United States)

    Erdei, Z.; Horgos, M.; Grib, A.; Preradović, D. M.; Rodic, V.

    2016-08-01

    This paper presents an experimental investigation in to operating of thermal protection device behavior from an MCCB (Molded Case Circuit Breaker). One of the main functions of the circuit breaker is to assure protection for the circuits where mounted in for possible overloads of the circuit. The tripping mechanism for the overload protection is based on a bimetal movement during a specific time frame. This movement needs to be controlled and as a solution to control this movement we choose the warm adjustment concept. This concept is meant to improve process capability control and final output. The warm adjustment device design will create a unique adjustment of the bimetal position for each individual breaker, determined when the testing current will flow thru a phase which needs to trip in a certain amount of time. This time is predetermined due to scientific calculation for all standard types of amperages and complies with the IEC 60497 standard requirements.

  19. Cosmic rays and global warming

    Energy Technology Data Exchange (ETDEWEB)

    Erlykin, A.D. [P.N. Lebedev Physical Institute, Moscow (Russian Federation); Sloan, T. [Lancaster University (United Kingdom); Wolfendale, A.W. [Durham University (United Kingdom)

    2010-07-01

    The possible effects of cosmic rays on clouds could contribute to global warming. The argument is that the observed increased solar activity during the last century caused a decrease in the ionization due to cosmic rays since the lower energy cosmic particles are deflected by the magnetic field created by the increasing solar wind. This would lead to a decrease in cloud cover allowing more heating of the earth by the sun. Meteorological data combined to solar activity observations and simulations show that any effect of solar activity on clouds and the climate is likely to be through irradiance rather than cosmic rays. Since solar irradiance transfers 8 orders of magnitude more energy to the atmosphere than cosmic rays it is more plausible that this can produce a real effect. The total contribution of variable solar activity to global warming is shown to be less than 14% of the total temperature rise. (A.C.)

  20. Global Warming Blame the Sun

    CERN Document Server

    Calder, N

    1997-01-01

    Concern about climate change reaches a political peak at a UN conference in Kyoto, 1-10 December, but behind the scenes the science is in turmoil. A challenge to the hypothesis that greenhouse gases are responsible for global warming comes from the discovery that cosmic rays from the Galaxy are involved in making clouds (Svensmark and Friis-Christensen, 1997). During the 20th Century the wind from the Sun has grown stronger and the count of cosmic rays has diminished. With fewer clouds, the EarthÕs surface has warmed up. This surprising mechanism explains the link between the Sun and climate change that astronomers and geophysicists have suspected for 200 years.

  1. PR Software: Warm Water Energie met grafieken

    NARCIS (Netherlands)

    Kanis, J.; Verstappen-Boerekamp, J.

    1999-01-01

    Het computerprogramma Warm Water Energie (WWE) berekent het verbruik van (warm) water, energie en reinigingsmiddelen bij de melkwinning. De nieuwste versie bevat grafieken die in één oogopslag de productie en het verbruik van warm water weergeven. In de overzichtelijke rapportage staan nu ook de sub

  2. Global warming and greenhouse gases

    OpenAIRE

    Belić Dragoljub S.

    2006-01-01

    Global warming or Climate change refers to long-term fluctuations in temperature, precipitation, wind, and other elements of the Earth's climate system. Natural processes such as solar-irradiance variations, variations in the Earth's orbital parameters, and volcanic activity can produce variations in climate. The climate system can also be influenced by changes in the concentration of various gases in the atmosphere, which affect the Earth's absorption of radiation.

  3. Global warming and urbanization affect springwater temperatures in Tokyo, Japan

    Science.gov (United States)

    Matsuyama, H.

    2014-02-01

    Due to global warming and urbanization, air temperature in Tokyo has risen 1.6 degrees in the past 30-40 years which has also affected springwater temperatures. From 2005, we have proceeded with the observations of springs in Tokyo metropolis, Japan which had been conducted by Environment of Tokyo from the end of the 1980s to 2001. In the rainy season (October) and dry season (February), we have observed springwater temperatures in 25 springs. The field surveys have revealed that most springwater temperatures has steadly risen in the past 30 years. As of February 2013, water temperatures of 19/11 springs have risen with 5% level in the rainy/dry season. As of February 2006, water temperatures of 10/13 springs have risen with 5% level in the rainy/dry season, i.e., 9/2 springs have acquired/lost the significance as of February 2013. One possible reason is the recent hot summer/cold winter in Tokyo.

  4. Debating about the climate warming

    Institute of Scientific and Technical Information of China (English)

    WANG Shaowu; LUO Yong; ZHAO Zongci; DONG Wenje; YANG Bao

    2006-01-01

    Debating about the climate warming is reviewed. Discussions have focused on the validity of the temperature reconstruction for the last millennium made by Mann et al. Arguments against and for the reconstruction are introduced. Temperature reconstructions by other authors are examined, including the one carried out by Wang et al. in 1996. It is concluded that: (1) Ability of reproducing temperature variability of time scale less than 10 a is limited, so no sufficient evidence proves that the 1990s was the warmest decade, and 1998 was the warmest year over the last millennium. (2) All ofthe temperature reconstructions by different authors demonstrate the occurrence of the MWP (Medieval Warm Period) and LIA (Little Ice Age) in low frequency band of temperature variations, though the peak in the MWP and trough in LIA varies from one reconstruction to the others. Therefore, terms of MWP and LIA can be used in studies of climate change. (3) The warming from 1975 to 2000 was significant, but we do not know if it was the strongest for the last millennium, which needs to be proved by more evidence.

  5. Global warming: Economic policy responses

    Energy Technology Data Exchange (ETDEWEB)

    Dornbusch, R.; Poterba, J.M. (eds.)

    1991-01-01

    This volume contains the proceedings of a conference that brought together economic experts from Europe, the US, Latin America, and Japan to evaluate key issues in the policy debate in global warming. The following issues are at the center of debates on alternative policies to address global warming: scientific evidence on the magnitude of global warming and the extent to which it is due to human activities; availability of economic tools to control the anthropogenic emissions of greenhouse gases, and how vigorously should they be applied; and political economy considerations which influence the design of an international program for controlling greenhouse gases. Many perspectives are offered on the approaches to remedying environmental problems that are currently being pursued in Europe and the Pacific Rim. Deforestation in the Amazon is discussed, as well as ways to slow it. Public finance assessments are presented of both the domestic and international policy issues raised by plans to levy a tax on the carbon emissions from various fossil fuels. Nine chapters have been processed separately for inclusion in the appropriate data bases.

  6. The Discovery of Global Warming

    Science.gov (United States)

    MacCracken, Michael C.

    2004-07-01

    At the beginning of the twentieth century, the prospect of ``global warming'' as a result of human activities was thought to be far off, and in any case, likely to be beneficial. As we begin the twenty-first century, science adviser to the British government, Sir David King, has said that he considers global warming to be the world's most important problem, including terrorism. Yet, dealing with it has become the subject of a contentious international protocol, numerous conferences of international diplomats, and major scientific assessments and research programs. Spencer Weart, who is director of the Center for History of Physics of the American Institute of Physics, has taken on the challenge of explaining how this came to be. In the tradition of the Intergovernmental Panel on Climate Change (IPCC), which was established in 1988 to evaluate and assess the state of global warming science, this book is roughly equivalent to the Technical Summary, in terms of its technical level, being quite readable, but with substantive content about the main lines of evidence. Underpinning this relatively concise presentation, there is a well-developed-and still developing-Web site that, like the detailed chapters of the full IPCC assessment reports, provides vastly more information and linkages to a much wider set of reference materials (see http://www.aip.org/history/climate).

  7. Effects of in situ climate warming on monarch caterpillar (Danaus plexippus) development

    Science.gov (United States)

    Capdevielle, Jillian N.; Parker, John D.

    2015-01-01

    Climate warming will fundamentally alter basic life history strategies of many ectothermic insects. In the lab, rising temperatures increase growth rates of lepidopteran larvae but also reduce final pupal mass and increase mortality. Using in situ field warming experiments on their natural host plants, we assessed the impact of climate warming on development of monarch (Danaus plexippus) larvae. Monarchs were reared on Asclepias tuberosa grown under ‘Ambient’ and ‘Warmed’ conditions. We quantified time to pupation, final pupal mass, and survivorship. Warming significantly decreased time to pupation, such that an increase of 1 °C corresponded to a 0.5 day decrease in pupation time. In contrast, survivorship and pupal mass were not affected by warming. Our results indicate that climate warming will speed the developmental rate of monarchs, influencing their ecological and evolutionary dynamics. However, the effects of climate warming on larval development in other monarch populations and at different times of year should be investigated. PMID:26528403

  8. Indoor Exposure to "Outdoor PM10" Assessing Its Influence on the Relationship Between PM10 and Short-term Mortality in US Cities

    DEFF Research Database (Denmark)

    Chen, Chun; Zhao, Bin; Weschler, Charles J.

    2012-01-01

    Background: Seasonal and regional differences have been reported for the increase in short-term mortality associated with a given increase in the concentration of outdoor particulate matter with an aerodynamic diameter smaller than 10 mu m (PM10 mortality coefficient). Some of this difference may......). Conclusions: Seasonal and regional differences in PM10 mortality coefficients appear to partially reflect seasonal and regional differences in total PM10 exposure per unit change in outdoor exposure....

  9. Environmental temperature and mortality

    OpenAIRE

    Näyhä, Simo

    2005-01-01

    In Finland, mortality increases steeply in autumn, reaches a peak during the Christhmas holidays and declines slowly towards a trough in August. The relative excess in daily mortality (peak vs. trough) is 30% for coronary heart disease, 40% for cerebral vascular accidents and 90% for diseases of the respiratory organs. There is a secondary peak in Midsummer, especially in coronary deaths of working aged men. Mortality is lowest at mean daily temperature of +14 degrees C, and it increases slow...

  10. Warm Dense Matter: An Overview

    Energy Technology Data Exchange (ETDEWEB)

    Kalantar, D H; Lee, R W; Molitoris, J D

    2004-04-21

    This document provides a summary of the ''LLNL Workshop on Extreme States of Materials: Warm Dense Matter to NIF'' which was held on 20, 21, and 22 February 2002 at the Wente Conference Center in Livermore, CA. The warm dense matter regime, the transitional phase space region between cold material and hot plasma, is presently poorly understood. The drive to understand the nature of matter in this regime is sparking scientific activity worldwide. In addition to pure scientific interest, finite temperature dense matter occurs in the regimes of interest to the SSMP (Stockpile Stewardship Materials Program). So that obtaining a better understanding of WDM is important to performing effective experiments at, e.g., NIF, a primary mission of LLNL. At this workshop we examined current experimental and theoretical work performed at, and in conjunction with, LLNL to focus future activities and define our role in this rapidly emerging research area. On the experimental front LLNL plays a leading role in three of the five relevant areas and has the opportunity to become a major player in the other two. Discussion at the workshop indicated that the path forward for the experimental efforts at LLNL were two fold: First, we are doing reasonable baseline work at SPLs, HE, and High Energy Lasers with more effort encouraged. Second, we need to plan effectively for the next evolution in large scale facilities, both laser (NIF) and Light/Beam sources (LCLS/TESLA and GSI) Theoretically, LLNL has major research advantages in areas as diverse as the thermochemical approach to warm dense matter equations of state to first principles molecular dynamics simulations. However, it was clear that there is much work to be done theoretically to understand warm dense matter. Further, there is a need for a close collaboration between the generation of verifiable experimental data that can provide benchmarks of both the experimental techniques and the theoretical capabilities

  11. Maternal mortality from hemorrhage.

    Science.gov (United States)

    Haeri, Sina; Dildy, Gary A

    2012-02-01

    Hemorrhage remains as one of the top 3 obstetrics related causes of maternal mortality, with most deaths occurring within 24-48 hours of delivery. Although hemorrhage related maternal mortality has declined globally, it continues to be a vexing problem. More specifically, the developing world continue to shoulder a disproportionate share of hemorrhage related deaths (99%) compared with industrialized nations (1%). Given the often preventable nature of death from hemorrhage, the cornerstone of effective mortality reduction involves risk factor identification, quick diagnosis, and timely management. In this monograph we will review the epidemiology, etiology, and preventative measures related to maternal mortality from hemorrhage.

  12. Mortality and GH deficiency

    DEFF Research Database (Denmark)

    Stochholm, Kirstine; Gravholt, Claus Højbjerg; Laursen, Torben;

    2007-01-01

    OBJECTIVE: To estimate the mortality in Denmark in patients suffering from GH deficiency (GHD). DESIGN: Mortality was analyzed in 1794 GHD patients and 8014 controls matched on age and gender. All records in GHD patients were studied and additional morbidity noted. Patients were divided into chil......OBJECTIVE: To estimate the mortality in Denmark in patients suffering from GH deficiency (GHD). DESIGN: Mortality was analyzed in 1794 GHD patients and 8014 controls matched on age and gender. All records in GHD patients were studied and additional morbidity noted. Patients were divided...

  13. Modelling middle pliocene warm climates of the USA

    Science.gov (United States)

    Haywood, A.M.; Valdes, P.J.; Sellwood, B.W.; Kaplan, J.O.; Dowsett, H.J.

    2001-01-01

    The middle Pliocene warm period represents a unique time slice in which to model and understand climatic processes operating under a warm climatic regime. Palaeoclimatic model simulations, focussed on the United States of America (USA), for the middle Pliocene (ca 3 Ma) were generated using the USGS PRISM2 2?? ?? 2?? data set of boundary conditions and the UK Meteorological Office's HadAMS General Circulation Model (GCM). Model results suggest that conditions in the USA during the middle Pliocene can be characterised as annually warmer (by 2?? to 4??C), less seasonal, wetter (by a maximum of 4 to 8 mm/day) and with an absence of freezing winters over the central and southern Great Plains. A sensitivity experiment suggests that the main forcing mechanisms for surface temperature changes in near coastal areas are the imposed Pliocene sea surface temperatures (SST's). In interior regions, reduced Northern Hemisphere terrestrial ice, combined with less snow cover and a reduction in the elevation of the western cordillera of North America, generate atmospheric circulation changes and positive albedo feedbacks that raise surface temperatures. A complex set of climatic feedback mechanisms cause an enhancement of the hydrological cycle magnifying the moisture bearing westerly wind belt during the winter season (Dec., Jan., Feb.). Predictions produced by the model are in broad agreement with available geological evidence. However, the GCM appears to underestimate precipitation levels in the interior and central regions of the southern USA. Copyright: Palaeontological Association, 22 June 2001.

  14. Implications of global warming for the climate of African rainforests.

    Science.gov (United States)

    James, Rachel; Washington, Richard; Rowell, David P

    2013-01-01

    African rainforests are likely to be vulnerable to changes in temperature and precipitation, yet there has been relatively little research to suggest how the regional climate might respond to global warming. This study presents projections of temperature and precipitation indices of relevance to African rainforests, using global climate model experiments to identify local change as a function of global temperature increase. A multi-model ensemble and two perturbed physics ensembles are used, one with over 100 members. In the east of the Congo Basin, most models (92%) show a wet signal, whereas in west equatorial Africa, the majority (73%) project an increase in dry season water deficits. This drying is amplified as global temperature increases, and in over half of coupled models by greater than 3% per °C of global warming. Analysis of atmospheric dynamics in a subset of models suggests that this could be partly because of a rearrangement of zonal circulation, with enhanced convection in the Indian Ocean and anomalous subsidence over west equatorial Africa, the Atlantic Ocean and, in some seasons, the Amazon Basin. Further research to assess the plausibility of this and other mechanisms is important, given the potential implications of drying in these rainforest regions.

  15. Plant phenological synchrony increases under rapid within-spring warming

    Science.gov (United States)

    Wang, Cong; Tang, Yanhong; Chen, Jin

    2016-05-01

    Phenological synchrony influences many ecological processes. Recent climate change has altered the synchrony of phenology, but little is known about the underlying mechanisms. Here using in situ phenological records from Europe, we found that the standard deviation (SD, as a measure of synchrony) of first leafing day (FLD) and the SD of first flowering day (FFD) among local plants were significantly smaller in the years and/or in the regions with a more rapid within-spring warming speed (WWS, the linear slope of the daily mean temperature against the days during spring, in oC/day) with correlation coefficients of ‑0.75 and ‑0.48 for FLD and ‑0.55 and ‑0.23 for FFD. We further found that the SDs of temperature sensitivity of local plants were smaller under the rapid WWS conditions with correlation coefficients of ‑0.46 and ‑0.33 for FLD and FFD respectively. This study provides the first evidence that the within-season rate of change of the temperature but not the magnitude determines plant phenological synchrony. It implies that temporally, the asymmetric seasonal climatic warming may decrease the synchrony via increasing WWS, especially in arctic regions; spatially, plants in coastal and low latitude areas with low WWS would have more diverse spring phenological traits.

  16. Lagging adaptation to warming climate in Arabidopsis thaliana

    Science.gov (United States)

    Wilczek, Amity M.; Cooper, Martha D.; Korves, Tonia M.; Schmitt, Johanna

    2014-01-01

    If climate change outpaces the rate of adaptive evolution within a site, populations previously well adapted to local conditions may decline or disappear, and banked seeds from those populations will be unsuitable for restoring them. However, if such adaptational lag has occurred, immigrants from historically warmer climates will outperform natives and may provide genetic potential for evolutionary rescue. We tested for lagging adaptation to warming climate using banked seeds of the annual weed Arabidopsis thaliana in common garden experiments in four sites across the species’ native European range: Valencia, Spain; Norwich, United Kingdom; Halle, Germany; and Oulu, Finland. Genotypes originating from geographic regions near the planting site had high relative fitness in each site, direct evidence for broad-scale geographic adaptation in this model species. However, genotypes originating in sites historically warmer than the planting site had higher average relative fitness than local genotypes in every site, especially at the northern range limit in Finland. This result suggests that local adaptive optima have shifted rapidly with recent warming across the species’ native range. Climatic optima also differed among seasonal germination cohorts within the Norwich site, suggesting that populations occurring where summer germination is common may have greater evolutionary potential to persist under future warming. If adaptational lag has occurred over just a few decades in banked seeds of an annual species, it may be an important consideration for managing longer-lived species, as well as for attempts to conserve threatened populations through ex situ preservation. PMID:24843140

  17. Assessing impact of climate change on season length in Karnataka for IPCC SRES scenarios

    Indian Academy of Sciences (India)

    Aavudai Anandhi

    2010-08-01

    Changes in seasons and season length are an indicator, as well as an effect, of climate change. Seasonal change profoundly affects the balance of life in ecosystems and impacts essential human activities such as agriculture and irrigation. This study investigates the uncertainty of season length in Karnataka state, India, due to the choice of scenarios, season type and number of seasons. Based on the type of season, the monthly sequences of variables (predictors) were selected from datasets of NCEP and Canadian General Circulation Model (CGCM3). Seasonal stratifications were carried out on the selected predictors using K-means clustering technique. The results of cluster analysis revealed increase in average, wet season length in A2, A1B and B1 scenarios towards the end of 21st century. The increase in season length was higher for A2 scenario whereas it was the least for B1 scenario. COMMIT scenario did not show any change in season length. However, no change in average warm and cold season length was observed across the four scenarios considered. The number of seasons was increased from 2 to 5. The results of the analysis revealed that no distinct cluster could be obtained when the number of seasons was increased beyond three.

  18. Methods of patient warming during abdominal surgery.

    Directory of Open Access Journals (Sweden)

    Li Shao

    Full Text Available BACKGROUND: Keeping abdominal surgery patients warm is common and warming methods are needed in power outages during natural disasters. We aimed to evaluate the efficacy of low-cost, low-power warming methods for maintaining normothermia in abdominal surgery patients. METHODS: Patients (n = 160 scheduled for elective abdominal surgery were included in this prospective clinical study. Five warming methods were applied: heated blood transfusion/fluid infusion vs. unheated; wrapping patients vs. not wrapping; applying moist dressings, heated or not; surgical field rinse heated or not; and applying heating blankets or not. Patients' nasopharyngeal and rectal temperatures were recorded to evaluate warming efficacy. Significant differences were found in mean temperatures of warmed patients compared to those not warmed. RESULTS: When we compared temperatures of abdominal surgery patient groups receiving three specific warming methods with temperatures of control groups not receiving these methods, significant differences were revealed in temperatures maintained during the surgeries between the warmed groups and controls. DISCUSSION: The value of maintaining normothermia in patients undergoing abdominal surgery under general anesthesia is accepted. Three effective economical and practically applicable warming methods are combined body wrapping and heating blanket; combined body wrapping, heated moist dressings, and heating blanket; combined body wrapping, heated moist dressings, and warmed surgical rinse fluid, with or without heating blanket. These methods are practically applicable when low-cost method is indeed needed.

  19. Global warming and obesity: a systematic review.

    Science.gov (United States)

    An, R; Ji, M; Zhang, S

    2017-10-04

    Global warming and the obesity epidemic are two unprecedented challenges mankind faces today. A literature search was conducted in the PubMed, Web of Science, EBSCO and Scopus for articles published until July 2017 that reported findings on the relationship between global warming and the obesity epidemic. Fifty studies were identified. Topic-wise, articles were classified into four relationships - global warming and the obesity epidemic are correlated because of common drivers (n = 21); global warming influences the obesity epidemic (n = 13); the obesity epidemic influences global warming (n = 13); and global warming and the obesity epidemic influence each other (n = 3). We constructed a conceptual model linking global warming and the obesity epidemic - the fossil fuel economy, population growth and industrialization impact land use and urbanization, motorized transportation and agricultural productivity and consequently influences global warming by excess greenhouse gas emission and the obesity epidemic by nutrition transition and physical inactivity; global warming also directly impacts obesity by food supply/price shock and adaptive thermogenesis, and the obesity epidemic impacts global warming by the elevated energy consumption. Policies that endorse deployment of clean and sustainable energy sources, and urban designs that promote active lifestyles, are likely to alleviate the societal burden of global warming and obesity. © 2017 World Obesity Federation.

  20. Artificial climate warming positively affects arbuscular mycorrhizae but decreases soil aggregate water stability in an annual grassland

    Energy Technology Data Exchange (ETDEWEB)

    Rillig, M.C.; Wright, S.F.; Shaw, M.R.; Field, C.B.

    2002-04-01

    Despite the importance of arbuscular mycorrhizae to the functioning of terrestrial ecosystems (e.g. nutrient uptake, soil aggregation), and the increasing evidence of global warming, responses of arbuscular mycorrhizal fungi (AMF) to climate warming are poorly understood. In a field experiment using infrared heaters, we found effects of warming on AMF after one growing season in an annual grassland, in the absence of any effects on measured root parameters (weight, length, average diameter). AMF soil hyphal length was increased by over 40% in the warmed plots, accompanied by a strong trend for AMF root colonization increase. In the following year, root weight was again not significantly changed, and AMF root colonization increased significantly in the warmed plots. Concentration of the soil protein glomalin, a glycoprotein produced by AMF hyphae with importance in soil aggregation, was decreased in the warmed plots. Soil aggregate water stability, measured for five diameter size classes, was also decreased significantly. In the following year, soil aggregate weight in two size classes was decreased significantly, but the effect size was very small. These results indicate that ecosystem warming may have stimulated carbon allocation to AMF. Other factors either influenced glomalin decomposition or production, hence influencing the role of these symbionts in soil aggregation. The observed small changes in soil aggregation, if widespread among terrestrial ecosystems, could have important consequences for soil carbon storage and erosion in a warmed climate, especially if there are cumulative effects of warming. (au)

  1. The effects of warming and nitrogen addition on soil nitrogen cycling in a temperate grassland, northeastern China.

    Directory of Open Access Journals (Sweden)

    Lin-Na Ma

    Full Text Available BACKGROUND: Both climate warming and atmospheric nitrogen (N deposition are predicted to affect soil N cycling in terrestrial biomes over the next century. However, the interactive effects of warming and N deposition on soil N mineralization in temperate grasslands are poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: A field manipulation experiment was conducted to examine the effects of warming and N addition on soil N cycling in a temperate grassland of northeastern China from 2007 to 2009. Soil samples were incubated at a constant temperature and moisture, from samples collected in the field. The results showed that both warming and N addition significantly stimulated soil net N mineralization rate and net nitrification rate. Combined warming and N addition caused an interactive effect on N mineralization, which could be explained by the relative shift of soil microbial community structure because of fungal biomass increase and strong plant uptake of added N due to warming. Irrespective of strong intra- and inter-annual variations in soil N mineralization, the responses of N mineralization to warming and N addition did not change during the three growing seasons, suggesting independence of warming and N responses of N mineralization from precipitation variations in the temperate grassland. CONCLUSIONS/SIGNIFICANCE: Interactions between climate warming and N deposition on soil N cycling were significant. These findings will improve our understanding on the response of soil N cycling to the simultaneous climate change drivers in temperate grassland ecosystem.

  2. Warm compacting behavior of stainless steel powders

    Institute of Scientific and Technical Information of China (English)

    肖志瑜; 柯美元; 陈维平; 召明; 李元元

    2004-01-01

    The warm compacting behaviors of four different kinds of stainless steel powders, 304L, 316L, 410L and 430L, were studied. The results show that warm compaction can be applied to stainless steel powders. The green densities and strengths of compacts obtained through warm compaction are generally higher than those obtained through cold compaction. The compacting behaviors in warm compaction and cold compaction are similar.Under the compacting pressure of 700 MPa, the warm compacted densities are 0. 10 - 0.22 g/cm3 higher than the cold compacted ones, and the green strengths are 11.5 %-50 % higher. The optimal warm compacting temperature is 100 - 110 ℃. In the die wall lubricated warm compaction, the optimum internal lubricant content is 0.2%.

  3. Seasonal smooth transition autoregression

    NARCIS (Netherlands)

    Ph.H.B.F. Franses (Philip Hans); P. de Bruin (Paul); D.J.C. van Dijk (Dick)

    2000-01-01

    textabstractIn this paper we put forward a new time series model, which describes nonlinearity and seasonality simultaneously. We discuss its representation, estimation of the parameters and inference. This seasonal STAR (SEASTAR) model is examined for its practical usefulness by applying it to 18 q

  4. Teaching with the Seasons.

    Science.gov (United States)

    Weber, Larry

    1998-01-01

    Describes a natural science course designed to teach students that nature is nearby rather than somewhere else. Students learn about local flora and fauna, track the weather, and closely monitor the progression of the seasons. The course uses no textbook, regularly uses the outdoors as a classroom, and follows the seasons' phenology as the…

  5. Spurious deterministic seasonality

    NARCIS (Netherlands)

    Ph.H.B.F. Franses (Philip Hans); S. Hylleberg; H.S. Lee (Hahn)

    1995-01-01

    textabstractIt is sometimes assumed that the R2 of a regression of a first-order differenced time series on seasonal dummy variables reflects the amount of seasonal fluctuations that can be explained by deterministic variation in the series. In this paper we show that neglecting the presence of seas

  6. Effects of global warming on ancient mammalian communities and their environments.

    Directory of Open Access Journals (Sweden)

    Larisa R G DeSantis

    Full Text Available BACKGROUND: Current global warming affects the composition and dynamics of mammalian communities and can increase extinction risk; however, long-term effects of warming on mammals are less understood. Dietary reconstructions inferred from stable isotopes of fossil herbivorous mammalian tooth enamel document environmental and climatic changes in ancient ecosystems, including C(3/C(4 transitions and relative seasonality. METHODOLOGY/PRINCIPAL FINDINGS: Here, we use stable carbon and oxygen isotopes preserved in fossil teeth to document the magnitude of mammalian dietary shifts and ancient floral change during geologically documented glacial and interglacial periods during the Pliocene (approximately 1.9 million years ago and Pleistocene (approximately 1.3 million years ago in Florida. Stable isotope data demonstrate increased aridity, increased C(4 grass consumption, inter-faunal dietary partitioning, increased isotopic niche breadth of mixed feeders, niche partitioning of phylogenetically similar taxa, and differences in relative seasonality with warming. CONCLUSION/SIGNIFICANCE: Our data show that global warming resulted in dramatic vegetation and dietary changes even at lower latitudes (approximately 28 degrees N. Our results also question the use of models that predict the long term decline and extinction of species based on the assumption that niches are conserved over time. These findings have immediate relevance to clarifying possible biotic responses to current global warming in modern ecosystems.

  7. Warm summers during Younger Dryas cold reversal over Eurasia

    Science.gov (United States)

    Schenk, Frederik; Muschitiello, Francesco; Heikkilä, Miaja; Väliranta, Minna; Tarasov, Lev; Brandefelt, Jenny; Johansson, Arne; Näslund, Jens-Ove; Wohlfarth, Barbara

    2016-04-01

    The Younger Dryas cold reversal (GS-1) sticks out as a major stadial interrupting the mid to late deglaciation with a sharp temperature drop of several degrees around the North Atlantic with global teleconnections. The abrupt return to a very cold glacial-like ocean state introduces a strong temperature anomaly to the climate system contrasting the high solar radiation received by northern summers. Here we show that, in contrast to earlier coarse resolution climate simulations of the Younger Dryas, these competing factors result in rather warm summer conditions over Eurasia comparable to the preceding warm period of the late Allerød (GI-1a). Despite up to 10 K colder sea-surface-temperatures in summer, our high resolution simulation with the Community Earth System Model 1 (CESM1.0.5) suggests that the presence of large ice sheets over Scandinavia, Spitsbergen and the Kara Sea significantly modifies atmospheric flow in summer preventing cold westerly winds from the Atlantic to impact the continent. Instead, fluid dynamics around ice sheets deflect winds to the north or south along the coasts supported by divergent flow from ice domes, stratification and increased tendency to high pressure and atmospheric blocking. Consistent with our model simulation, we show that temperature reconstructions derived from an extended compilation of multi-proxy lake records (chironomids, aquatic pollen, macrofossils) suggest warm July conditions of 13-17° C for continental Europe with exception of coastal and high elevation sites. The analysis of simulated growing degree days, season length and first results from paleo lake modelling driven by climate model output suggests that severe winter to spring conditions significantly delay and shorten the vegetation season but do not produce cold summers as previously simulated.

  8. Climate warming and its impact on natural regional boundaries in China in the 1980s

    Institute of Scientific and Technical Information of China (English)

    SHA; Wanying; (沙万英); SHAO; Xuemei; (邵雪梅); HUANG; Mei; (黄玫)

    2002-01-01

    The global climate warming accelerated in the 1980s has become a focus in the world. Based on the month by month and year by year temperature data from 160 representative stations throughout the country during 1951-1999, this paper analyses annual and four seasons' temperature variations of China since the 1980s. It was found out that the non-equalibrium response with relative great regional and seasonal differences is represented in the country's climate warming. In regional changes a trend of "warm in the north and cold in the south" occurs whereas in seasonal changes, the characters of "warm in winter and cool in summer" present. Significant verification of the temperature variations conducted in terms of mathematical statistics reveals that a confidence level of over 95% has been basically reached in areas north of the Yangtze River. Meanwhile, according to data of diurnal mean temperature steadily passing through accumulated temperature ≥10℃ from 335 stations since 1951 or since the founding of the stations in the early 1950s to 1999, comparative analysis of the data of the last 19 years with that of the first 30 years was conducted and the accumulated temperature ≥10℃ and the variation range of the persistent number of days ≥10℃ were obtained. It was concluded that a general northward shift of central subtropics, north subtropics, warm temperate zone, mesothermal zone and frigid temperate zone of eastern China was observed. The northward shift of north subtropics and warm temperate zone was obvious but changes of south subtropics and marginal tropics were insignificant. In western China, in addition to southwestern Yunnan, the Qinghai-Tibet Plateau and western Inner Mongolia where the temperature zones of each either shifted northward or trended to move upward, not much changes were found in other areas or they shifted southward slightly and declined.

  9. Effects of soil warming on CO2 efflux in tundra soil: Response to a 2015 episodic event

    Science.gov (United States)

    Kim, Y.; Park, S. J.; Kim, B. M.; Cho, M. H.; Suzuki, R.; Lee, B. Y.; Walsh, J. E.

    2016-12-01

    Soil carbon emission is vulnerable to changes in temperature, moisture, and the organic carbon stored in tundra soil. Emissions can therefore be affected by recent Arctic climate change and warming. Here, we conducted soil CO2 efflux measurements in the tundra ecosystem of western Alaska, during the growing seasons of 2014 and 2015, in order to assess the effect of soil warming on soil carbon emission from a 2015 episodic warming event. Soil carbon emissions were greater in 2015 than in 2014, resulting from 1) a dry growing season and lower soil moisture, 2) increases in TDDs (total degree days of above 0 °C) for soil temperature at deeper active layers of 50, 70, and 80-cm depths, 3) deeper thaw depth of the active layer, and 4) stronger PAR (photosynthetically active radiation) during the growing season of 2015. These findings demonstrate the response from the decomposability of old-aged organic carbon matter from naturally occurring increased soil temperature at a deeper active layer, and subsequently, enhanced soil carbon emission to the atmosphere (e.g., 9 % higher in 2015 than in 2014) during the growing season. The findings also imply that soil warming-induced soil carbon emissions contribute an additional atmospheric carbon source and an accelerating positive feedback to climate change in the Arctic during the growing season.

  10. Global Warming and Its Health Impact.

    Science.gov (United States)

    Rossati, Antonella

    2017-01-01

    Since the mid-19th century, human activities have increased greenhouse gases such as carbon dioxide, methane, and nitrous oxide in the Earth's atmosphere that resulted in increased average temperature. The effects of rising temperature include soil degradation, loss of productivity of agricultural land, desertification, loss of biodiversity, degradation of ecosystems, reduced fresh-water resources, acidification of the oceans, and the disruption and depletion of stratospheric ozone. All these have an impact on human health, causing non-communicable diseases such as injuries during natural disasters, malnutrition during famine, and increased mortality during heat waves due to complications in chronically ill patients. Direct exposure to natural disasters has also an impact on mental health and, although too complex to be quantified, a link has even been established between climate and civil violence. Over time, climate change can reduce agricultural resources through reduced availability of water, alterations and shrinking arable land, increased pollution, accumulation of toxic substances in the food chain, and creation of habitats suitable to the transmission of human and animal pathogens. People living in low-income countries are particularly vulnerable. Climate change scenarios include a change in distribution of infectious diseases with warming and changes in outbreaks associated with weather extreme events. After floods, increased cases of leptospirosis, campylobacter infections and cryptosporidiosis are reported. Global warming affects water heating, rising the transmission of water-borne pathogens. Pathogens transmitted by vectors are particularly sensitive to climate change because they spend a good part of their life cycle in a cold-blooded host invertebrate whose temperature is similar to the environment. A warmer climate presents more favorable conditions for the survival and the completion of the life cycle of the vector, going as far as to speed it up

  11. Global Warming and Its Health Impact

    Directory of Open Access Journals (Sweden)

    Antonella Rossati

    2017-01-01

    Full Text Available Since the mid-19th century, human activities have increased greenhouse gases such as carbon dioxide, methane, and nitrous oxide in the Earth's atmosphere that resulted in increased average temperature. The effects of rising temperature include soil degradation, loss of productivity of agricultural land, desertification, loss of biodiversity, degradation of ecosystems, reduced fresh-water resources, acidification of the oceans, and the disruption and depletion of stratospheric ozone. All these have an impact on human health, causing non-communicable diseases such as injuries during natural disasters, malnutrition during famine, and increased mortality during heat waves due to complications in chronically ill patients. Direct exposure to natural disasters has also an impact on mental health and, although too complex to be quantified, a link has even been established between climate and civil violence. Over time, climate change can reduce agricultural resources through reduced availability of water, alterations and shrinking arable land, increased pollution, accumulation of toxic substances in the food chain, and creation of habitats suitable to the transmission of human and animal pathogens. People living in low-income countries are particularly vulnerable. Climate change scenarios include a change in distribution of infectious diseases with warming and changes in outbreaks associated with weather extreme events. After floods, increased cases of leptospirosis, campylobacter infections and cryptosporidiosis are reported. Global warming affects water heating, rising the transmission of water-borne pathogens. Pathogens transmitted by vectors are particularly sensitive to climate change because they spend a good part of their life cycle in a cold-blooded host invertebrate whose temperature is similar to the environment. A warmer climate presents more favorable conditions for the survival and the completion of the life cycle of the vector, going as far

  12. Recent severe heat waves: how to view them in a 'global warming' perspective?

    Science.gov (United States)

    Kysely, J.

    2010-03-01

    The area of western and central Europe has recently been affected by several long-lasting and severe heat waves, particularly in July-August 2003, June-July 2006, and July 2007. The heat waves influenced various sectors of human activities, with enormous socio-economic impacts. With an estimated death toll exceeding 50000 over Europe, the August 2003 heat wave was the worst natural disaster in Europe during the last 50 years, yielding an example of how seriously may also high-income countries be affected by climate change. The aims of the study are to assess whether recent occurrences of severe heat waves in central Europe were exceptional in the context of past fluctuations, and to estimate their recurrence probabilities under future climate change scenarios. We focus on analogs of the 2006 heat wave which lasted 33 consecutive days in Prague and was the longest and most severe heat wave since the beginning of air temperature measurements in 1775. Probabilities of long and severe heat waves are estimated from daily temperature series generated by a first-order autoregressive model with a deterministic component, incorporating the seasonal cycle and the long-term trend. The model is validated with respect to the simulation of heat waves in present climate (1961-2006) and subsequently run under several assumptions reflecting various rates of summer warming over the 21st century, based on climate model projections. The return period of a heat wave reaching or exceeding the length of the 2006 heat wave is estimated to be around 120 years in 2006. Due to an increase in mean summer temperatures, probabilities of very long heat waves have already risen by an order of magnitude over the recent 25 years, and they are likely to increase by another order of magnitude by around 2040 under the summer warming rate assumed by the mid-scenario. Even the lower-bound scenario yields a considerable decline of return periods associated with intense heat waves. Although positive socio

  13. Mortality in ankylosing spondylitis

    DEFF Research Database (Denmark)

    Exarchou, Sofia; Lie, Elisabeth; Lindström, Ulf

    2016-01-01

    OBJECTIVES: Information on mortality in ankylosing spondylitis (AS) is scarce. Our study therefore aimed to assess: (1) mortality in AS versus the general population, and (2) predictors of death in the AS population. METHODS: Nationwide cohorts of patients with AS diagnosed at rheumatology...

  14. Mortality associated with phaeochromocytoma

    NARCIS (Netherlands)

    Prejbisz, A.; Lenders, J.W.M.; Eisenhofer, G.; Januszewicz, A.

    2013-01-01

    Two major categories of mortality are distinguished in patients with phaeochromocytoma. First, the effects of excessive circulating catecholamines may result in lethal complications if the disease is not diagnosed and/or treated timely. The second category of mortality is related to development of m

  15. Impact of climate change on mid-twenty-first century growing seasons in Africa

    Energy Technology Data Exchange (ETDEWEB)

    Cook, Kerry H.; Vizy, Edward K. [The University of Texas at Austin, Department of Geological Sciences, Jackson School of Geosciences, Austin, TX (United States)

    2012-12-15

    Changes in growing seasons for 2041-2060 across Africa are projected using a regional climate model at 90-km resolution, and confidence in the predictions is evaluated. The response is highly regional over West Africa, with decreases in growing season days up to 20% in the western Guinean coast and some regions to the east experiencing 5-10% increases. A longer growing season up to 30% in the central and eastern Sahel is predicted, with shorter seasons in parts of the western Sahel. In East Africa, the short rains (boreal fall) growing season is extended as the Indian Ocean warms, but anomalous mid-tropospheric moisture divergence and a northward shift of Sahel rainfall severely curtails the long rains (boreal spring) season. Enhanced rainfall in January and February increases the growing season in the Congo basin by 5-15% in association with enhanced southwesterly moisture transport from the tropical Atlantic. In Angola and the southern Congo basin, 40-80% reductions in austral spring growing season days are associated with reduced precipitation and increased evapotranspiration. Large simulated reductions in growing season over southeastern Africa are judged to be inaccurate because they occur due to a reduction in rainfall in winter which is over-produced in the model. Only small decreases in the actual growing season are simulated when evapotranspiration increases in the warmer climate. The continent-wide changes in growing season are primarily the result of increased evapotranspiration over the warmed land, changes in the intensity and seasonal cycle of the thermal low, and warming of the Indian Ocean. (orig.)

  16. Cutaneous warming promotes sleep onset.

    Science.gov (United States)

    Raymann, Roy J E M; Swaab, Dick F; Van Someren, Eus J W

    2005-06-01

    Sleep occurs in close relation to changes in body temperature. Both the monophasic sleep period in humans and the polyphasic sleep periods in rodents tend to be initiated when core body temperature is declining. This decline is mainly due to an increase in skin blood flow and consequently skin warming and heat loss. We have proposed that these intrinsically occurring changes in core and skin temperatures could modulate neuronal activity in sleep-regulating brain areas (Van Someren EJW, Chronobiol Int 17: 313-54, 2000). We here provide results compatible with this hypothesis. We obtained 144 sleep-onset latencies while directly manipulating core and skin temperatures within the comfortable range in eight healthy subjects under controlled conditions. The induction of a proximal skin temperature difference of only 0.78 +/- 0.03 degrees C (mean +/- SE) around a mean of 35.13 +/- 0.11 degrees C changed sleep-onset latency by 26%, i.e., by 3.09 minutes [95% confidence interval (CI), 1.91 to 4.28] around a mean of 11.85 min (CI, 9.74 to 14.41), with faster sleep onsets when the proximal skin was warmed. The reduction in sleep-onset latency occurred despite a small but significant decrease in subjective comfort during proximal skin warming. The induction of changes in core temperature (delta = 0.20 +/- 0.02 degrees C) and distal skin temperature (delta = 0.74 +/- 0.05 degrees C) were ineffective. Previous studies have demonstrated correlations between skin temperature and sleep-onset latency. Also, sleep disruption by ambient temperatures that activate thermoregulatory defense mechanisms has been shown. The present study is the first to experimentally demonstrate a causal contribution to sleep-onset latency of skin temperature manipulations within the normal nocturnal fluctuation range. Circadian and sleep-appetitive behavior-induced variations in skin temperature might act as an input signal to sleep-regulating systems.

  17. Influenza excess mortality from 1950-2000 in tropical Singapore.

    Directory of Open Access Journals (Sweden)

    Vernon J Lee

    Full Text Available INTRODUCTION: Tropical regions have been shown to exhibit different influenza seasonal patterns compared to their temperate counterparts. However, there is little information about the burden of annual tropical influenza epidemics across time, and the relationship between tropical influenza epidemics compared with other regions. METHODS: Data on monthly national mortality and population was obtained from 1947 to 2003 in Singapore. To determine excess mortality for each month, we used a moving average analysis for each month from 1950 to 2000. From 1972, influenza viral surveillance data was available. Before 1972, information was obtained from serial annual government reports, peer-reviewed journal articles and press articles. RESULTS: The influenza pandemics of 1957 and 1968 resulted in substantial mortality. In addition, there were 20 other time points with significant excess mortality. Of the 12 periods with significant excess mortality post-1972, only one point (1988 did not correspond to a recorded influenza activity. For the 8 periods with significant excess mortality periods before 1972 excluding the pandemic years, 2 years (1951 and 1953 had newspaper reports of increased pneumonia deaths. Excess mortality could be observed in almost all periods with recorded influenza outbreaks but did not always exceed the 95% confidence limits of the baseline mortality rate. CONCLUSION: Influenza epidemics were the likely cause of most excess mortality periods in post-war tropical Singapore, although not every epidemic resulted in high mortality. It is therefore important to have good influenza surveillance systems in place to detect influenza activity.

  18. Relative effects of precipitation variability and warming on tallgrass prairie ecosystem function

    Directory of Open Access Journals (Sweden)

    P. A. Fay

    2011-10-01

    Full Text Available Precipitation and temperature drive many aspects of terrestrial ecosystem function. Climate change scenarios predict increasing precipitation variability and temperature, and long term experiments are required to evaluate the ecosystem consequences of interannual climate variation, increased growing season (intra-annual rainfall variability, and warming. We present results from an experiment applying increased growing season rainfall variability and year round warming in native tallgrass prairie. During ten years of study, total growing season rainfall varied 2-fold, and we found ~50–200% interannual variability in plant growth and aboveground net primary productivity (ANPP, leaf carbon assimilation (ACO2, and soil CO2 efflux (JCO2 despite only ~40% variation in mean volumetric soil water content (0–15 cm, Θ15. Interannual variation in soil moisture was thus amplified in most measures of ecosystem response. Differences between years in Θ15 explained the greatest portion (14–52% of the variation in these processes. Experimentally increased intra-annual season rainfall variability doubled the amplitude of intra-annual soil moisture variation and reduced Θ15 by 15%, causing most ecosystem processes to decrease 8–40% in some or all years with increased rainfall variability compared to ambient rainfall timing, suggesting reduced ecosystem rainfall use efficiency. Warming treatments increased soil temperature at 5 cm depth, particularly during spring, fall, and winter. Warming advanced canopy green up in spring, increased winter JCO2, and reduced summer JCO2 and forb ANPP, suggesting that the effects of warming differed in cooler versus warmer parts of the year. We conclude that (1 major ecosystem processes in this grassland may be substantially altered by predicted changes in

  19. Soil Temperature Manipulation to Study Global Warming Effects in Arable Land

    DEFF Research Database (Denmark)

    Patil, R H; Laegdsmand, M; Olesen, Jørgen E

    2013-01-01

    in a plough layer. Temperature sensors were placed at 0.05, 0.1 and 0.25 m depths in soil, and 0.1 m above the soil surface in all plots, which were connected to an automated data logger. Soil-warming setup was able to maintain a mean seasonal temperature difference of 5.0 ± 0.005℃ between heated and control......-ground vegetation response as this method heats only the soil. Therefore, using infrared heaters seems to represent natural climate warming (both air and soil) much more closely and may be used for future climate manipulation field studies....

  20. Soil temperature manipulation to study global warming effects in arable land

    DEFF Research Database (Denmark)

    Patil, Raveendra H.; Laegdsmand, Mette; Olesen, Jørgen Eivind

    2013-01-01

    in a plough layer. Temperature sensors were placed at 0.05, 0.1 and 0.25 m depths in soil, and 0.1 m above the soil surface in all plots, which were connected to an automated data logger. Soil-warming setup was able to maintain a mean seasonal temperature difference of 5.0 ± 0.005 oC between heated...... that of above-ground vegetation response as this method heats only the soil. Therefore, using infrared heaters seems to represent natural climate warming (both air and soil) much more closely and may be used for future climate manipulation field studies....

  1. Soil Temperature Manipulation to Study Global Warming Effects in Arable Land

    DEFF Research Database (Denmark)

    Patil, R H; Laegdsmand, M; Olesen, Jørgen E

    2013-01-01

    in a plough layer. Temperature sensors were placed at 0.05, 0.1 and 0.25 m depths in soil, and 0.1 m above the soil surface in all plots, which were connected to an automated data logger. Soil-warming setup was able to maintain a mean seasonal temperature difference of 5.0 ± 0.005℃ between heated and control......-ground vegetation response as this method heats only the soil. Therefore, using infrared heaters seems to represent natural climate warming (both air and soil) much more closely and may be used for future climate manipulation field studies....

  2. An assessment of global warming stress on Caribbean coral reef ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Atwood, D.K.; Hendec, J.C.; Mendez, A. (NOAA, Miami, FL (USA). Atlantic Oceanography and Meteorology Laboratory)

    1992-07-01

    There is evidence that stress on coral reef ecosystems in the Caribbean region is increasing. Recently numerous authors have stated that the major stress results from 'abnormally high' seasonal sea surface temperatures (SST) and have implicated global warming as a cause, stating that recent episodes of coral bleaching result therefrom. However, an analysis of available SST data sets shows no discernible warming trend that could cause an increase in coral bleaching. Given the lack of long-term records synoptic with observations of coral ecosystem health, there is insufficient evidence available to label temperatures observed in coincidence with recent regional bleaching events as 'abnormally' high.

  3. Short-term effects of daily air pollution on mortality

    Science.gov (United States)

    Wan Mahiyuddin, Wan Rozita; Sahani, Mazrura; Aripin, Rasimah; Latif, Mohd Talib; Thach, Thuan-Quoc; Wong, Chit-Ming

    2013-02-01

    The daily variations of air pollutants in the Klang Valley, Malaysia, which includes Kuala Lumpur were investigated for its association with mortality counts using time series analysis. This study located in the tropic with much less seasonal variation than typically seen in more temperate climates. Data on daily mortality for the Klang Valley (2000-2006), daily mean concentrations of air pollutants of PM10, SO2, CO, NO2, O3, daily maximum O3 and meteorological conditions were obtained from Malaysian Department of Environment. We examined the association between pollutants and daily mortality using Poisson regression while controlling for time trends and meteorological factors. Effects of the pollutants (Relative Risk, RR) on current-day (lag 0) mortality to seven previous days (lag 7) and the effects of the pollutants from the first two days (lag 01) to the first eight days (lag 07) were determined. We found significant associations in the single-pollutant model for PM10 and the daily mean O3 with natural mortality. For the daily mean O3, the highest association was at lag 05 (RR = 1.0215, 95% CI = 1.0013-1.0202). CO was found not significantly associated with natural mortality, however the RR's of CO were found to be consistently higher than PM10. In spite of significant results of PM10, the magnitude of RR's of PM10 was not important for natural mortality in comparison with either daily mean O3 or CO. There is an association between daily mean O3 and natural mortality in a two-pollutants model after adjusting for PM10. Most pollutants except SO2, were significantly associated with respiratory mortality in a single pollutant model. Daily mean O3 is also important for respiratory mortality, with over 10% of mortality associated with every IQR increased. These findings are noteworthy because seasonal confounding is unlikely in this relatively stable climate, by contrast with more temperate regions.

  4. Seasonality of fire weather strongly influences fire regimes in South Florida savanna-grassland landscapes.

    Science.gov (United States)

    Platt, William J; Orzell, Steve L; Slocum, Matthew G

    2015-01-01

    Fire seasonality, an important characteristic of fire regimes, commonly is delineated using seasons based on single weather variables (rainfall or temperature). We used nonparametric cluster analyses of a 17-year (1993-2009) data set of weather variables that influence likelihoods and spread of fires (relative humidity, air temperature, solar radiation, wind speed, soil moisture) to explore seasonality of fire in pine savanna-grassland landscapes at the Avon Park Air Force Range in southern Florida. A four-variable, three-season model explained more variation within fire weather variables than models with more seasons. The three-season model also delineated intra-annual timing of fire more accurately than a conventional rainfall-based two-season model. Two seasons coincided roughly with dry and wet seasons based on rainfall. The third season, which we labeled the fire season, occurred between dry and wet seasons and was characterized by fire-promoting conditions present annually: drought, intense solar radiation, low humidity, and warm air temperatures. Fine fuels consisting of variable combinations of pyrogenic pine needles, abundant C4 grasses, and flammable shrubs, coupled with low soil moisture, and lightning ignitions early in the fire season facilitate natural landscape-scale wildfires that burn uplands and across wetlands. We related our three season model to fires with different ignition sources (lightning, military missions, and prescribed fires) over a 13-year period with fire records (1997-2009). Largest wildfires originate from lightning and military ignitions that occur within the early fire season substantially prior to the peak of lightning strikes in the wet season. Prescribed ignitions, in contrast, largely occur outside the fire season. Our delineation of a pronounced fire season provides insight into the extent to which different human-derived fire regimes mimic lightning fire regimes. Delineation of a fire season associated with timing of

  5. Cool Season Paleotemperatures at Tree Line in Taiwan

    Science.gov (United States)

    Wright, W. E.; Chan, M.

    2011-12-01

    Taiwan has over 200 mountains whose peaks exceed 3,000 meters in elevation. Despite straddling the Tropic of Cancer, the higher peaks have snow and freezing temperatures every winter. Trees growing above 3,500 meters show clear temperature variation, even producing frost rings. Yet unlike temperate tree-line species, with their warm season temperature signal, trees growing at Taiwan's tree line show sensitivity to cool season temperatures. Juniperus squamata growing above 3,500 meters in central Taiwan have ring width time series that commonly exceed 600 years. Presented are the first dendroclimatological analyses from Taiwanese Juniperus squamata.

  6. Century-Long Warming Trends in the Upper Water Column of Lake Tanganyika.

    Directory of Open Access Journals (Sweden)

    Benjamin M Kraemer

    Full Text Available Lake Tanganyika, the deepest and most voluminous lake in Africa, has warmed over the last century in response to climate change. Separate analyses of surface warming rates estimated from in situ instruments, satellites, and a paleolimnological temperature proxy (TEX86 disagree, leaving uncertainty about the thermal sensitivity of Lake Tanganyika to climate change. Here, we use a comprehensive database of in situ temperature data from the top 100 meters of the water column that span the lake's seasonal range and lateral extent to demonstrate that long-term temperature trends in Lake Tanganyika depend strongly on depth, season, and latitude. The observed spatiotemporal variation in surface warming rates accounts for small differences between warming rate estimates from in situ instruments and satellite data. However, after accounting for spatiotemporal variation in temperature and warming rates, the TEX86 paleolimnological proxy yields lower surface temperatures (1.46 °C lower on average and faster warming rates (by a factor of three than in situ measurements. Based on the ecology of Thaumarchaeota (the microbes whose biomolecules are involved with generating the TEX86 proxy, we offer a reinterpretation of the TEX86 data from Lake Tanganyika as the temperature of the low-oxygen zone, rather than of the lake surface temperature as has been suggested previously. Our analyses provide a thorough accounting of spatiotemporal variation in warming rates, offering strong evidence that thermal and ecological shifts observed in this massive tropical lake over the last century are robust and in step with global climate change.

  7. Warming increases isoprene emissions from an arctic fen.

    Science.gov (United States)

    Lindwall, Frida; Svendsen, Sophie Sylvest; Nielsen, Cecilie Skov; Michelsen, Anders; Rinnan, Riikka

    2016-05-15

    Emissions of biogenic volatile organic compounds (BVOCs) from dry ecosystems at high latitudes respond strongly to small increases in temperature, and warm canopy surface temperatures drive emissions to higher levels than expected. However, it is not known whether emissions from wetlands, cooled by through-flowing water and higher evapotranspiration show similar response to warming as in drier ecosystems. Climate change will cause parts of the Arctic to experience increased snow fall, which delays the start of the growing season, insulates soil from low temperatures in winter, and increases soil moisture and possibly nutrient availability. Currently the effects of increasing snow depth on BVOC emissions are unknown. BVOC emissions were measured in situ across the growing season in a climate experiment, which used open top chambers to increase temperature and snow fences to increase winter snow depth. The treatments were arranged in a full factorial design. Measurements took place during two growing seasons in a fen ecosystem in west Greenland. BVOC samples collected by an enclosure technique in adsorbent cartridges were analysed using gas chromatography-mass spectrometry. Gross ecosystem production (GEP) was measured with a closed chamber technique, to reveal any immediate effect of treatments on photosynthesis, which could further influence BVOC emissions. Isoprene made up 84-92% of the emitted BVOCs. Isoprene emission increased 240 and 340% due to an increase in temperature of 1.3 and 1.6°C in 2014 and 2015, respectively. Isoprene emissions were 25 times higher in 2015 than in 2014 most likely due to a 2.4°C higher canopy air temperature during sampling in 2015. Snow addition had no significant effect on isoprene emissions even though GEP was increased by 24%. Arctic BVOC emissions respond strongly to rising temperatures in wet ecosystems, suggesting a large increase in arctic emissions in a future warmer climate.

  8. Identification of a seasonal pattern to brain metastases

    Directory of Open Access Journals (Sweden)

    Sakellakis M

    2016-03-01

    Full Text Available Minas Sakellakis,1 Angelos Koutras,1 Maria Pittaka,2 Dimitrios Kardamakis,2 Melpomeni Kalofonou,1 Haralabos P Kalofonos,1 Despina Spyropoulou2 1Division of Oncology, Department of Medicine, 2Department of Radiation Oncology, University Hospital, Patras Medical School, Rion, Patras, GreeceWe have previously tested our hypothesis that there is a seasonality in the incidence of carcinomatous meningitis.1 Although further validation is needed in a larger cohort, we found that leptomeningeal metastasis occurred more often during warm months of the year which, in the case of Greece, is the period generally marked with the larger daytime length.1 Carcinomatous meningitis is closely related to brain metastasis, and a logical question is whether warm season is marked by a greater propensity also for brain metastasis.2 

  9. Orbital control of low-latitude seasonality during the Eemian

    Science.gov (United States)

    Winter, A.; Paul, A.; Nyberg, J.; Oba, T.; Lundberg, J.; Schrag, D.; Taggart, B.

    2003-01-01

    We used Sr/Ca and stable isotope data from well dated and preserved corals from the northeastern Caribbean to determine the seasonal environmental conditions for four continuous years during the Eemian, the last time the Earth was in a prolonged warm phase. We determined that the seasonal range in SST during the Eemian was 25??-30?? C. This is ???1-2?? larger than at present and caused primarily by winter cooling and, only to a small degree, by summer warming. As climate modeling studies indicate, the bias towards colder winters can be explained by changes in low latitude insolation induced by altered orbital parameters, modulated by atmospheric CO2 levels that were lower than today. Milankovitch forcing at higher latitudes was probably less important.

  10. The case of the missing mechanism: how does temperature influence seasonal timing in endotherms?

    Directory of Open Access Journals (Sweden)

    Samuel P Caro

    Full Text Available Temperature has a strong effect on the seasonal timing of life-history stages in both mammals and birds, even though these species can regulate their body temperature under a wide range of ambient temperatures. Correlational studies showing this effect have recently been supported by exp