Nederhoff, E.M.; Houter, G.
Greenhouse operators strive to be as economic as possible with energy. However, investing in fancy energy-saving equipment is often not cost-effective for smaller operations and in climate zones with mild winters. It is possible, though, for many growers to save energy without buying special equipme
Munoz-Salinas, E.; Castillo, M.
The Sierra Madre de Chiapas (SMC) is a steep mountain range located in the south-western part of Mexico with elevations higher than 2000 m. The SMC is ~30 km off the Pacific Coast and it is oriented parallel to the coast. The annual rainfall exceeds 6 m and most of this takes place during summer season when low-pressure systems and cyclones are frequent. The rivers in SMC incise into the granite and transport large volumes of sediment. Even though rivers can be regarded as bedrock bedrock channels these suddenly change to alluvial-type rivers when these flow in the coastal plain which is ~10 km from the headwater of rivers. There are not data available of the sediment yield of rivers, however, the well-broad coastal plain and the wide continental shelf suggest that the sediment transport from the mountain area to the lowlands is significantly high. Here we assess the main morphological, climatic and structural factors controlling water discharge and sediment load of the rivers flowing from the SMC to the Pacific Coast by means of (1) topographical analysis on a high-resolution DEM, (2) grain-size and OSL analysis on sediment extracted from the riverbed of the main rivers and (3) time-series analysis from the available data of sediment discharge and sediment load. Our results indicate that the river incision and sediment transport is particularly high at the southern sector of the SMC where the topographic and climatic factors promote higher erosion rates.
Kasischke, E. S.; Johnstone, J. F.; Rupp, S.; Duffy, P. A.; Kielland, K.; Chapin, F. S.
There is a general consensus that future warming in the North American Boreal Region will cause a reduction in coniferous species common to cool, wet sites and an increase in deciduous/coniferous species found on warmer drier sites. In addition, it is believed that much of the change in forest cover will occur during secondary succession following disturbance and that the frequency of disturbance is likely to increase in response to climate warming; however, neither the rate at forest cover will change, nor the mechanisms thereof are well understood. Here, we summarize results from recent studies in Alaska that are being carried out as part of the Bonanza Creek Long Term Ecological Research Project and research being funded by the Joint Fire Science Program and NASA. We have examined factors important in regulating the change in the extent of black spruce (Picea mariana), a dominant forest type across the North American boreal region. Depth of burning of the surface organic layer is a fire severity measure that is important in regulating the post-fire environment in black spruce forests. In particular, seeds from deciduous trees have extremely low germination rates in post-fire organic soils that are greater than 3 cm deep. In addition, we found the growth of deciduous species in burned stands is inversely proportional to the depth of the remaining organic soil, with the highest growth observed on sites with exposed mineral soils. Other factors controlling seedling survival and growth include soil temperature and moisture, nutrient availability, and the fact that deciduous and coniferous species have different capabilities in absorbing different forms of soil nitrogen. These additional factors are also controlled by the amount of organic soil remaining after the fire. Finally, our research has shown that the depth of the remaining organic soil after fires is controlled both by topography and climate, with the frequency of sites with organic layers shallower than 3
Climate modification measures to counteract global warming receive some more new attentions in these years. Most current researches only discuss the impact of these measures to climate, but how to design such a climate regulator is still unknown. This paper shows the control theory could give the systematic direction for climate modification. But the control analyzing also reveals that climate modifications should only be regarded as a last-ditch measure.
ÁKOS NÉMETH; JÁNOS MIKA
Weather and climate risk factors for tourism are surveyed and illustrated with regard to the expected climate changes in Hungary. These changes are not at all advantageous and which affect the business in question both directly and indirectly. These are the summer resort tourism (characterised by bioclimatic indices). Green tourism is the next one to characterise, including skiing, mountain climbing and eco-tourism, as well. Here both day-to-day weather extremes and long-lasting effects on th...
Overgaard, Anne Blach; Svenning, J.-C.; Dransfield, John;
-climatic environmental predictors, the latter having no discernible effect beyond the climatic control. Hence, at the continental scale, climate constitutes the only strong environmental control of palm species distributions in Africa. With regard to the most important climatic predictors of African palm distributions......, water-related factors were most important for 25 of the 29 species analysed. The strong response of palm distributions to climate in combination with the importance of non-environmental spatial constraints suggests that African palms will be sensitive to future climate changes, but that their ability to...
Full Text Available This study examined the difference in the levels of the variables related to the schoolclimate factors among the teachers teaching social science courses, the teachers teaching natural science courses,and the teachers teaching art, music and physical education. The data collected from a sample of 204 teachersfrom 9 urban schools serving general high school education in the centre of Afyon and Usak cities in Turkey bymeans of the questionnaire developed by the researcher in the academic year of 2001-2002. The questionnaireasked the participants to report the perceived school climate levels of the variables related to the organizationalclimate factors - organizational clarity and standards, team commitment, autonomy, intimacy and support,member conflict, rewards, and risk - on the open-to-closed continuum. The data collected were analyzed by t-testfor Equality of Means and Analysis of Variance and Tukey post hoc tests. As a result of the analyzes, all theteachers reported open climate in relation to the factors of team commitment, organizational clarity andstandards, intimacy and support , autonomy, member conflict, medium climate in relation to the factors of riskand in reward. Additionally, the teachers teaching art, music and physical education reported higher open schoolclimate than others, man than women, single teachers than married ones, the teachers with more degree ofeducation than the ones with a lower degree of education, older teachers than younger ones, and the teacherswith less seniority than the ones with more seniority. Finally, some ideas were suggested about what should bedone in helping teachers to work in a more desirable open school climate
Full Text Available Weather and climate risk factors for tourism are surveyed and illustrated with regard to the expected climate changes in Hungary. These changes are not at all advantageous and which affect the business in question both directly and indirectly. These are the summer resort tourism (characterised by bioclimatic indices. Green tourism is the next one to characterise, including skiing, mountain climbing and eco-tourism, as well. Here both day-to-day weather extremes and long-lasting effects on the biota (e.g. drought, or inundation for plain-area eco-tourism. Last, but not least the urban (cultural- and shopping- tourism is presented, since the large towns exhibit their special climate and different risks. The paper intends to specify these meteorological factors and effects also in terms of the different types of touristic activities. The general statements on the effect of weather and climate on tourism are illustrated by a few individual parameters and also by the so called Physiologically Equivalent Temperature. Annual and diurnal course of this parameter are presented, together with various trends in this variable at different sites and in different (hot and cold extremities of the occurring values. Other examples, helping the tourism industry are presented in various climate conditions of the country. They include high precipitation and high relative humidity information. The paper also lists the possible adaptation measures to extreme events and also their likely changes in time.
Arvidsson, Marcus; Johansson, Curt R; Ek, Åsa; Akselsson, Roland
In a joint project – Human Factors in ANS, HUFA - between the Swedish Civil Aviation Administration and Lund University the aim is to find out how a new team-based organization and the introduction of a new air traffic control system will affect safety culture and psychosocial working environment by changes in organizational climate, team climate and leadership. All in all, four studies will be conducted, before and after the system introduction, involving the two air traffic control centers ...
Lunt, Daniel J.; Farnsworth, Alex; Loptson, Claire; Foster, Gavin L.; Markwick, Paul; O'Brien, Charlotte L.; Pancost, Richard D.; Robinson, Stuart A.; Wrobel, Neil
During the period from approximately 150 to 35 million years ago, the Cretaceous-Paleocene-Eocene (CPE), the Earth was in a "greenhouse" state with little or no ice at either pole. It was also a period of considerable global change, from the warmest periods of the mid-Cretaceous, to the threshold of icehouse conditions at the end of the Eocene. However, the relative contribution of palaeogeographic change, solar change, and carbon cycle change to these climatic variations is unknown. Here, making use of recent advances in computing power, and a set of unique palaeogeographic maps, we carry out an ensemble of 19 General Circulation Model simulations covering this period, one simulation per stratigraphic stage. By maintaining atmospheric CO2 concentration constant across the simulations, we are able to identify the contribution from palaeogeographic and solar forcing to global change across the CPE, and explore the underlying mechanisms. We find that global mean surface temperature is remarkably constant across the simulations, resulting from a cancellation of opposing trends from solar and palaeogeographic change. However, there are significant modelled variations on a regional scale. The stratigraphic stage-stage transitions which exhibit greatest climatic change are associated with transitions in the mode of ocean circulation, themselves often associated with changes in ocean gateways, and amplified by feedbacks related to emissivity and planetary albedo. We also find some control on global mean temperature from continental area and global mean orography. Our results have important implications for the interpretation of single-site palaeo proxy records. In particular, our results allow the non-CO2 (i.e. palaeogeographic and solar constant) components of proxy records to be removed, leaving a more global component associated with carbon cycle change. This "adjustment factor" is used to adjust sea surface temperatures, as the deep ocean is not fully equilibrated in
Yi, C.; Ricciuto, D.; Marek, Michal V.
Roč. 5, č. 3 (2010), s. 034007. ISSN 1748-9326 Institutional research plan: CEZ:AV0Z60870520 Keywords : NEE * climate control * terrestrial carbon sequestration * temperature * dryness * eddy flux * biomes * photosynthesis * respiration * global carbon cycle Subject RIV: EH - Ecology, Behaviour Impact factor: 3.049, year: 2010
Petersen, Lars Kjerulf; Jensen, Anne; Nielsen, Signe Svalgaard
risks and concerns of everyday life? The project found that the distinction between climate change mitigation and adaptation is of little significance for lay people. The prospect of climate change does provoke reflections on social values and the need for saving energy, but when it comes to protecting......This poster reports from a explorative study about social aspects of climate change adaptation in Denmark. The aim of the project was to explore how people perceive and relate to climate change adaptation, what risks are associated with climate change and how are those risks balanced with other...
Modgil, Moninder Singh
We examine implications of anthropogenic low pressure regions, - created by injecting heat from nuclear reactors, into atmosphere. We suggest the possibility that such artificially generated low pressure regions, near hurricanes could disrupt their growth, path, and intensity. This method can also create controlled tropical stroms, which lead to substantial rainfall in arid areas, such as - (1)Sahara desert, (2) Australian interior desert, and (3) Indian Thar desert. A simple vortex suction model is developed to study, effect on atmospheric dynamics, by such a nuclear heat injection system.
Scherber, Christoph; Gladbach, David J; Stevnbak, Karen;
The impact of climate change on herbivorous insects can have far-reaching consequences for ecosystem processes. However, experiments investigating the combined effects of multiple climate change drivers on herbivorous insects are scarce. We independently manipulated three climate change drivers (CO......, nitrogen, and water content. Overall, drought was the most important factor for this insect herbivore. Our study shows that weight and survival of insect herbivores may decline under future climate. The complexity of insect herbivore responses increases with the number of combined climate change drivers....
M., A W; H., P W M; Steskens,
The study focuses on the applicability of system identification to identify building and system dynamics for climate control design. The main problem regarding the simulation of the dynamic response of a building using building simulation software is that (1) the simulation of a large complex building is time consuming, and (2) simulation results often lack information regarding fast dynamic behaviour (in the order of seconds), since most software uses a discrete time step, usually fixed to one hour. The first objective is to study the applicability of system identification to reduce computing time for the simulation of large complex buildings. The second objective is to research the applicability of system identification to identify building dynamics based on discrete time data (one hour) for climate control design. The study illustrates that system identification is applicable for the identification of building dynamics with a frequency that is smaller as the maximum sample frequency as used for identificat...
Narayanan, S; Li, XS; Yang, S; Kim, H; Umans, A; McKay, IS; Wang, EN
Current technologies that provide climate control in the transportation sector are quite inefficient. In gasoline-powered vehicles, the use of air-conditioning is known to result in higher emissions of greenhouse gases and pollutants apart from decreasing the gas-mileage. On the other hand, for electric vehicles (EVs), a drain in the onboard electric battery due to the operation of heating and cooling system results in a substantial decrease in the driving range. As an alternative to the conventional climate control system, we are developing an adsorption-based thermal battery (ATB), which is capable of storing thermal energy, and delivering both heating and cooling on demand, while requiring minimal electric power supply. Analogous to an electrical battery, the ATB can be charged for reuse. Furthermore, it promises to be compact, lightweight, and deliver high performance, which is desirable for mobile applications. In this study, we describe the design and operation of the ATB-based climate control system. We present a general theoretical framework to determine the maximum achievable heating and cooling performance using the ATB. The framework is then applied to study the feasibility of ATB integration in EVs, wherein we analyze the use of NaX zeolite-water as the adsorbent-refrigerant pair. In order to deliver the necessary heating and cooling performance, exceeding 2.5 kW h thermal capacity for EVs, the analysis determines the optimal design and operating conditions. While the use of the ATB in EVs can potentially enhance its driving range, it can also be used for climate control in conventional gasoline vehicles, as well as residential and commercial buildings as a more efficient and environmentally-friendly alternative. (C) 2015 Elsevier Ltd. All rights reserved.
Li Lang; Wang Guangze; Xu Dezhong; Fang Liqun; Wang Shanqing; Long Yong; Xiao Dan; Cao Wuchun; Yan Yongping
Abstract Background Hainan is one of the provinces most severely affected by malaria epidemics in China. The distribution pattern and major determinant climate factors of malaria in this region have remained obscure, making it difficult to target countermeasures for malaria surveillance and control. This study detected the spatiotemporal distribution of malaria and explored the association between malaria epidemics and climate factors in Hainan. Methods The cumulative and annual malaria incid...
This study examined the difference in the levels of the variables related to the schoolclimate factors among the teachers teaching social science courses, the teachers teaching natural science courses,and the teachers teaching art, music and physical education. The data collected from a sample of 204 teachersfrom 9 urban schools serving general high school education in the centre of Afyon and Usak cities in Turkey bymeans of the questionnaire developed by the researcher in the academic year o...
Highlights: • ATB is adsorptive thermal battery delivering both heating and cooling via storage. • The novel design promotes transport and maximizes ATB performance. • A general theoretical framework is developed to analyze ATB performance. • NaX–water is used as the adsorbent–refrigerant pair as a specific case study. • The effect of key geometric parameters and operating conditions are presented. - Abstract: Current technologies that provide climate control in the transportation sector are quite inefficient. In gasoline-powered vehicles, the use of air-conditioning is known to result in higher emissions of greenhouse gases and pollutants apart from decreasing the gas-mileage. On the other hand, for electric vehicles (EVs), a drain in the onboard electric battery due to the operation of heating and cooling system results in a substantial decrease in the driving range. As an alternative to the conventional climate control system, we are developing an adsorption-based thermal battery (ATB), which is capable of storing thermal energy, and delivering both heating and cooling on demand, while requiring minimal electric power supply. Analogous to an electrical battery, the ATB can be charged for reuse. Furthermore, it promises to be compact, lightweight, and deliver high performance, which is desirable for mobile applications. In this study, we describe the design and operation of the ATB-based climate control system. We present a general theoretical framework to determine the maximum achievable heating and cooling performance using the ATB. The framework is then applied to study the feasibility of ATB integration in EVs, wherein we analyze the use of NaX zeolite–water as the adsorbent–refrigerant pair. In order to deliver the necessary heating and cooling performance, exceeding 2.5 kW h thermal capacity for EVs, the analysis determines the optimal design and operating conditions. While the use of the ATB in EVs can potentially enhance its driving
Three approaches commonly are identified for controlling automobile greenhouse gas (GHG) emissions: reducing travel demand, improving vehicle efficiency and using alternatively (non-petroleum) fueled vehicles (AFVs). Similarly, sector emissions are factored by travel distance, vehicle fuel intensity and fuel GHG (“carbon”) intensity. Analyzing these factors using US and China data reveals that for a broad range of conditions, stringent GHG emissions limits for the auto sector imply limits of comparable stringency for fuel carbon intensity. However, carbon intensity is a modeled representation of complex energy supply and use systems rather than a measurable property of fuels themselves. Carefully examining the locations and magnitudes of fuel-related emissions indicates that the proper policy focus is on the sectors that supply fuel rather than the choice of fuels in the auto sector. Therefore, beyond fundamental R and D, policies to commercialize AFVs are not necessarily required for climate protection at present. In addition to managing travel demand and improving vehicle efficiency, the implied policy priority is limiting net GHG impacts in the energy and other natural resource sectors that supply fuels. Future work is needed to develop GHG management protocols for liquid fuel supply systems involving fungible commodities and dynamic global supply chains. - Highlights: • Factor analysis offers insights about ways to reduce automotive GHG emissions. • Improving vehicle efficiency and reducing travel demand remain important. • Reducing net GHG impacts in energy sectors that supply motor fuels is also a priority. • Commercialization of alternatively fueled vehicles is not necessarily required at present
Scherber, Christoph; Gladbach, David J; Stevnbak, Karen;
the drought treatment, and there was a three-way interaction between time, CO2, and drought. Survival was lowest when drought, warming, and elevated CO2 were combined. Effects of climate change drivers depended on other co-acting factors and were mediated by changes in plant secondary compounds, nitrogen......The impact of climate change on herbivorous insects can have far-reaching consequences for ecosystem processes. However, experiments investigating the combined effects of multiple climate change drivers on herbivorous insects are scarce. We independently manipulated three climate change drivers (CO...... suturalis Thomson), an important herbivore on heather, to ambient versus elevated drought, temperature, and CO2 (plus all combinations) for 5 weeks. Larval weight and survival were highest under ambient conditions and decreased significantly with the number of climate change drivers. Weight was lowest under...
The construction of Baku-Tbilisi-Ceyhan (BTC) Oil and South Caucasus Gas (SCP) pipelines was completed in 2005. The Azerbaijan section of BTC Oil and SCP Gas pipelines is 442 km long and 44 m wide corridor named as the Right-of-Way. BTC and SCP pipelines are aligned parallel to each other within the same 44m corridor. The construction process of the pipelines significantly disturbed vegetation and soil cover along Right-of-Way of pipelines. The revegetation and erosion control measures were c...
Joyce Mendes Pereira; Paulo Silva de Almeida; Adair Vieira de Sousa; Aécio Moraes de Paula; Ricardo Bomfim Machado; Rodrigo Gurgel-Gonçalves
We estimated the geographic distributions of triatomine species in Central-West Region of Brazil (CW) and analysed the climatic factors influencing their occurrence. A total of 3,396 records of 27 triatomine species were analysed. Using the maximum entropy method, ecological niche models were produced for eight species occurring in at least 20 municipalities based on 13 climatic variables and elevation. Triatoma sordida and Rhodnius neglectus were the species with the broadest geographic dist...
Sørensen, Jan Corfixen
The slow adoption pace of new control strategies for sustainable greenhouse climate control by industrial growers, is mainly due to the complexity of identifying and resolving potentially conflicting climate control requirements. When separate climate control strategies are composed they become...... coupled through the shared environment resources. As a consequence, the greenhouse climate control system requirements may no longer be entailed when independent climate control strategies try to control the same shared environment phenomena. The problem emerges when control strategies interfere with one...... interaction manager provides visualization of the feature interactions, that allows the grower make an informed decision to resolve the interactions based on priorities and goals. The feature interaction manager is demonstrated in a real-life control system for industrial ornamental plant cultivation in...
Barron, O. V.; R. S. Crosbie; W. R. Dawes; S. P. Charles; T. Pickett; M. J. Donn
Reviews of field studies of groundwater recharge have attempted to investigate how climate characteristics control recharge, but due to a lack of data have not been able to draw any strong conclusions beyond that rainfall is the major determinant. This study has used numerical modelling for a range of Köppen-Geiger climate types (tropical, arid and temperate) to investigate the effect of climate variables on recharge for different soil and vegetation types. For the majority of climate types, ...
Barron, O. V.; R. S. Crosbie; D. Pollock; W. R. Dawes; S. P. Charles; T. Pickett; M. Donn
Reviews of field studies of groundwater recharge have attempted to investigate how climate characteristics control recharge, but due to a lack of data have not been able to draw any strong conclusions beyond that rainfall is the major determinant. This study has used numerical modeling for a range of Köppen-Geiger climate types (tropical, arid and temperate) to investigate the effect of climate variables on recharge for different soil and vegetation types. For the majority of climate t...
D. J. Lunt
Full Text Available During the period from approximately 150 to 35 million years ago, the Cretaceous–Paleocene–Eocene (CPE, the Earth was in a "greenhouse" state with little or no ice at either pole. It was also a period of considerable global change, from the warmest periods of the mid Cretaceous, to the threshold of icehouse conditions at the end of the Eocene. However, the relative contribution of palaeogeographic change, solar change, and carbon cycle change to these climatic variations is unknown. Here, making use of recent advances in computing power, and a set of unique palaeogeographic maps, we carry out an ensemble of 19 General Circulation Model simulations covering this period, one simulation per stratigraphic stage. By maintaining atmospheric CO2 concentration constant across the simulations, we are able to identify the contribution from palaeogeographic and solar forcing to global change across the CPE, and explore the underlying mechanisms. We find that global mean surface temperature is remarkably constant across the simulations, resulting from a cancellation of opposing trends from solar and paleogeographic change. However, there are significant modelled variations on a regional scale. The stratigraphic stage–stage transitions which exhibit greatest climatic change are associated with transitions in the mode of ocean circulation, themselves often associated with changes in ocean gateways, and amplified by feedbacks related to emissivity and albedo. Our results also have implications for the interpretation of single-site palaeo proxy records. In particular, our results allow the non-CO2 (i.e. palaeogeographic and solar constant components of proxy records to be removed, leaving a more global component associated with carbon cycle change. This "adjustment factor" is illustrated for 7 key sites in the CPE, and applied to proxy data from Falkland Plateau, and we provide data so that similar adjustments can be made to any site and for any time
O. V. Barron
Full Text Available Reviews of field studies of groundwater recharge have attempted to investigate how climate characteristics control recharge, but due to a lack of data have not been able to draw any strong conclusions beyond that rainfall is the major determinant. This study has used numerical modeling for a range of Köppen-Geiger climate types (tropical, arid and temperate to investigate the effect of climate variables on recharge for different soil and vegetation types. For the majority of climate types the total annual rainfall had a weaker correlation with recharge than the rainfall parameters reflecting rainfall intensity. In regions with winter-dominated rainfall, annual recharge under the same annual rainfall, soils and vegetation conditions is greater than in regions with summer-dominated rainfall. The relative importance of climate parameters other than rainfall is higher for recharge under annual vegetation, but overall is highest in the tropical climate type. Solar radiation and vapour pressure deficit show a greater relative importance than mean annual daily mean temperature. Climate parameters have lowest relative importance in the arid climate type (with cold winters and the temperate climate type. For 75% of all considered cases of soil, vegetation and climate types recharge elasticity varies between 2 and 4, indicating a 20% to 40% change in recharge for a 10% change in annual rainfall Understanding how climate controls recharge under the observed historical climate allows more informed choices of analogue sites if they are to be used for climate change impact assessments.
O. M. Grudnitskiy
Full Text Available It is shown that influence of climatic factor on production processes is necessary to be taken into account at planning of enterprise work: to carry out correction of production schedules, and also to vary specific norms of raw and materials consumption.
Howard, Richard T. (Inventor)
There is provided a climate control system for a parked vehicle that includes a solar panel, thermostatic switch, fans, and thermoelectric coolers. The solar panel can serve as the sole source of electricity for the system. The system affords convenient installation and removal by including solar panels that are removably attached to the exterior of a vehicle. A connecting wire electrically connects the solar panels to a housing that is removably mounted to a partially opened window on the vehicle. The thermostatic switch, fans, and thermoelectric coolers are included within the housing. The thermostatic switch alternates the direction of the current flow through the thermoelectric coolers to selectively heat or cool the interior of the vehicle. The interior surface of the thermoelectric coolers are in contact with interior heat sinks that have air circulated across them by an interior fan. Similarly, the exterior surface of the thermoelectric coolers are in contact with exterior heat sinks that have air circulated across them by an exterior fan.
Joyce Mendes Pereira
Full Text Available We estimated the geographic distributions of triatomine species in Central-West Region of Brazil (CW and analysed the climatic factors influencing their occurrence. A total of 3,396 records of 27 triatomine species were analysed. Using the maximum entropy method, ecological niche models were produced for eight species occurring in at least 20 municipalities based on 13 climatic variables and elevation. Triatoma sordida and Rhodnius neglectus were the species with the broadest geographic distributions in CW Brazil. The Cerrado areas in the state of Goiás were found to be more suitable for the occurrence of synanthropic triatomines than the Amazon forest areas in the northern part of the state of Mato Grosso. The variable that best explains the evaluated models is temperature seasonality. The results indicate that almost the entire region presents climatic conditions that are appropriate for at least one triatomine species. Therefore, it is recommended that entomological surveillance be reinforced in CW Brazil.
This paper aimed at finding causes of global warming and ways to bring it under control. Data based on scientific opinion as given by synthesis reports of news, articles, web sites, and books. global warming is the observed and projected increases in average temperature of Earth's atmosphere and oceans. Carbon dioxide and other air pollution that is collecting in the atmosphere like a thickening blanket, trapping the sun's heat and causing the planet to warm up. Pollution is one of the biggest man-made problems. Burning fossil fuels is the main factor of pollution. As average temperature increases, habitats, species and people are threatened by drought, changes in rainfall, altered seasons, and more violent storms and floods. Indeed the life cycle of nuclear power results in relatively little pollution. Energy efficiency, solar, wind and other renewable fuels are other weapons against global warming . Human activity, primarily burning fossil fuels, is the major driving factor in global warming . Curtailing the release of carbon dioxide into the atmosphere by reducing use of oil, gasoline, coal and employment of alternate energy, sources are the tools for keeping global warming under control. global warming can be slowed and stopped, with practical actions thal yield a cleaner, healthier atmosphere
Overheating is a paramount problem in residential buildings in hot and humid climates in China during summer. This study aims to deal with the overheating problem and the problem of poor air quality in dwellings. The main objective is to improve indoor thermal conditions by passive cooling approaches, climatisation techniques in buildings without auxiliary cooling from air conditioning equipment. This thesis focuses on the study of cross-ventilation in apartments, which is one of the most effective ways of natural cooling in a hot humid climate, but is also one of the least understood parts in controlling indoor climate. The Computational Fluid Dynamics (CFD) technique is used, which is a new approach, since cross-ventilation studies have been conventionally made by wind tunnel tests. The validations of the CFD technique are examined by a comparison between wind tunnel tests and computer simulations. The factors influencing indoor air movement are investigated for a single room. Cross-ventilation in two apartments is studied, and the air change efficiency in a Chinese kitchen is calculated with CFD techniques. The thermal performance of ventilated roofs, a simple and widely used type of roof in the region, is specially addressed by means of a full-scale measurement, wind tunnel tests and computer simulations. An integrated study of passive cooling approaches and factors affecting indoor thermal comfort is carried out through a case study in a southern Chinese city, Guangzhou. This thesis demonstrates that passive cooling measure have a high potential in significantly improving indoor thermal conditions during summer. This study also gives discussions and conclusions on the evaluation of indoor thermal environment; effects influencing cross-ventilation in apartments; design guidelines for ventilated roofs and an integrated study of passive cooling. 111 refs, 83 figs, 65 tabs
O. V. Barron
Full Text Available Reviews of field studies of groundwater recharge have attempted to investigate how climate characteristics control recharge, but due to a lack of data have not been able to draw any strong conclusions beyond that rainfall is the major determinant. This study has used numerical modelling for a range of Köppen-Geiger climate types (tropical, arid and temperate to investigate the effect of climate variables on recharge for different soil and vegetation types. For the majority of climate types, the correlation between the modelled recharge and total annual rainfall is weaker than the correlation between recharge and the annual rainfall parameters reflecting rainfall intensity. Under similar soil and vegetation conditions for the same annual rainfall, annual recharge in regions with winter-dominated rainfall is greater than in regions with summer-dominated rainfall. The importance of climate parameters other than rainfall in recharge estimation is highest in the tropical climate type. Mean annual values of solar radiation and vapour pressure deficit show a greater importance in recharge estimation than mean annual values of the daily mean temperature. Climate parameters have the lowest relative importance in recharge estimation in the arid climate type (with cold winters and the temperate climate type. For 75% of all soil, vegetation and climate types investigated, recharge elasticity varies between 2 and 4 indicating a 20% to 40% change in recharge for a 10% change in annual rainfall. Understanding how climate controls recharge under the observed historical climate allows more informed choices of analogue sites if they are to be used for climate change impact assessments.
Amstel, van A.R.
This study on CH4, (its role in climate change and options for control), aimed at a scenario analysis to assess future climate change under reduced methane emissions. At the same time improving the quality of CH4 emission inventories and estimating the costs of emission reducti
... disease: Know your risk Heart Health and Stroke Heart disease risk factors you can control Did you know? ... overall health. Return to top More information on Heart disease risk factors you can control Read more from ...
Habtemariam, Lemlem Teklegiorgis; Gandorfer, Markus; Kassa, Getachew Abate; Heissenhuber, Alois
Factors influencing climate change perceptions have vital roles in designing strategies to enrich climate change understanding. Despite this, factors that influence smallholder farmers' climate change perceptions have not yet been adequately studied. As many of the smallholder farmers live in regions where climate change is predicted to have the most negative impact, their climate change perception is of particular interest. In this study, based on data collected from Ethiopian smallholder farmers, we assessed farmers' perceptions and anticipations of past and future climate change. Furthermore, the factors influencing farmers' climate change perceptions and the relation between farmers' perceptions and available public climate information were assessed. Our findings revealed that a majority of respondents perceive warming temperatures and decreasing rainfall trends that correspond with the local meteorological record. Farmers' perceptions about the past climate did not always reflect their anticipations about the future. A substantial number of farmers' anticipations of future climate were less consistent with climate model projections. The recursive bivariate probit models employed to explore factors affecting different categories of climate change perceptions illustrate statistical significance for explanatory variables including location, gender, age, education, soil fertility status, climate change information, and access to credit services. The findings contribute to the literature by providing evidence not just on farmers' past climate perceptions but also on future climate anticipations. The identified factors help policy makers to provide targeted extension and advisory services to enrich climate change understanding and support appropriate farm-level climate change adaptations. PMID:27179801
Habtemariam, Lemlem Teklegiorgis; Gandorfer, Markus; Kassa, Getachew Abate; Heissenhuber, Alois
Factors influencing climate change perceptions have vital roles in designing strategies to enrich climate change understanding. Despite this, factors that influence smallholder farmers' climate change perceptions have not yet been adequately studied. As many of the smallholder farmers live in regions where climate change is predicted to have the most negative impact, their climate change perception is of particular interest. In this study, based on data collected from Ethiopian smallholder farmers, we assessed farmers' perceptions and anticipations of past and future climate change. Furthermore, the factors influencing farmers' climate change perceptions and the relation between farmers' perceptions and available public climate information were assessed. Our findings revealed that a majority of respondents perceive warming temperatures and decreasing rainfall trends that correspond with the local meteorological record. Farmers' perceptions about the past climate did not always reflect their anticipations about the future. A substantial number of farmers' anticipations of future climate were less consistent with climate model projections. The recursive bivariate probit models employed to explore factors affecting different categories of climate change perceptions illustrate statistical significance for explanatory variables including location, gender, age, education, soil fertility status, climate change information, and access to credit services. The findings contribute to the literature by providing evidence not just on farmers' past climate perceptions but also on future climate anticipations. The identified factors help policy makers to provide targeted extension and advisory services to enrich climate change understanding and support appropriate farm-level climate change adaptations.
was composed of three principal components and two autocorrelation terms. The association between HFRS epidemics and climate factors was better explained in the PCR model (F = 446.452, P R2 = 0.75 than in the general multiple regression model (F = 223.670, P R2 = 0.51. Conclusion The temporal distribution of HFRS in Shenyang varied in different years with a distinctly declining trend. The monthly trends of HFRS were significantly associated with local temperature, relative humidity, precipitation, air pressure, and wind velocity of the different previous months. The model conducted in this study will make HFRS surveillance simpler and the control of HFRS more targeted in Shenyang.
Amstel, van, R.J.
This study on CH4, (its role in climate change and options for control), aimed at a scenario analysis to assess future climate change under reduced methane emissions. At the same time improving the quality of CH4 emission inventories and estimating the costs of emission reductions between 2010 and 2100. In this thesis 28 major options to control or mitigate methane emissions from different sources were identified. The effectiveness and costs of these options were assessed. This resulted in a ...
Li, Jingwan; Sharma, Ashish; Johnson, Fiona; Evans, Jason
Areal reduction factors (ARFs) are commonly used to transform point design rainfall to represent the average design rainfall for a catchment area. While there has been considerable attention paid in the research and engineering communities to the likely changes in rainfall intensity in future climates, the issue of changes to design areal rainfall has been largely ignored. This paper investigates the impact of climate change on ARFs. A new methodology for estimating changes in ARFs is presented. This method is used to assess changes in ARFs in the greater Sydney region using a high-resolution regional climate model (RCM). ARFs under present (1990-2009) and future (2040-2059) climate conditions were derived and compared for annual exceedance probabilities (AEPs) from 50% to 5% for durations ranging from 1 h to 120 h. The analysis shows two main trends in the future changes in ARFs. For the shortest duration events (1-h) the ARFs are found to increase which implies that these events will tend to have a larger spatial structure in the future than the current climate. In contrast, storms with durations between 6 and 72 h are likely to have decreased ARFs in the future, suggesting a more restricted spatial coverage of storms under a warming climate. The extent of the decrease varies with event frequency and catchment size. The largest decreases are found for large catchments and rare events. Although the results here are based on a single RCM and need to be confirmed in future work with multiple models, the framework that is proposed will be useful for future studies considering changes in the areal extent of rainfall extremes.
Timmins, Mitchel; Yadav, Kamal; Iroanusi, Kennedy; Tickle, Andrew J.
This paper focuses on the development of a portable variable climate controlled system that can be tailored to the requirements of the item to be stored by manipulating the temperature, humidity and light levels within the controlled area. This could be used to store anything from bio-chemical samples (to preserve them from field work) to cooled electronics (prior to deployment in a given situation) to foodstuffs (such as wine and other alcohols). In this situation however, to provide a relatively simplistic example, the environment will be used to store wine. The system is adaptive in that anything can be stored within it, assuming the storage parameters are known in order to correctly configure the environment. In this paper a microcontroller (PICF4520) is connected to a fridge with various sensors attached to monitor and manipulate the environment and adjust it accordingly. For the chosen item to be stored, a temperature of 13- 14oC is required, a high humidity level and a non-Ultraviolent (UV) light source. This work thus allows for a small handheld unit that could be used to control the climate within without the need for the traditional 12 - 16 foot size portable units traditionally used. The unit could be left in the field and run off a solar cell to assist in longer term studies. This paper presents how the microcontroller is connected to the fridge and its sensors, how it manipulates the environment and the process by which the temperature and other factors can be changed without having to edit and recompile the C code, this allows for a much more friendly device interface.
Jeffers, M. A.; Chaney, L.; Rugh, J. P.
Passenger compartment climate control is one of the largest auxiliary loads on a vehicle. Like conventional vehicles, electric vehicles (EVs) require climate control to maintain occupant comfort and safety, but cabin heating and air conditioning have a negative impact on driving range for all electric vehicles. Range reduction caused by climate control and other factors is a barrier to widespread adoption of EVs. Reducing the thermal loads on the climate control system will extend driving range, thereby reducing consumer range anxiety and increasing the market penetration of EVs. Researchers at the National Renewable Energy Laboratory have investigated strategies for vehicle climate control load reduction, with special attention toward EVs. Outdoor vehicle thermal testing was conducted on two 2012 Ford Focus Electric vehicles to evaluate thermal management strategies for warm weather, including solar load reduction and cabin pre-ventilation. An advanced thermal test manikin was used to assess a zonal approach to climate control. In addition, vehicle thermal analysis was used to support testing by exploring thermal load reduction strategies, evaluating occupant thermal comfort, and calculating EV range impacts. Through stationary cooling tests and vehicle simulations, a zonal cooling configuration demonstrated range improvement of 6%-15%, depending on the drive cycle. A combined cooling configuration that incorporated thermal load reduction and zonal cooling strategies showed up to 33% improvement in EV range.
Basso, S.; Frascati, A.; Marani, M.; Schirmer, M.; Botter, G.
The effective discharge constitutes a key concept in river science and engineering. Notwithstanding many years of studies, a full understanding of the effective discharge determinants is still challenged by the variety of values identified for different river catchments. The present paper relates the observed diversity of effective discharge to the underlying heterogeneity of flow regimes. An analytic framework is proposed, which links the effective ratio (i.e., the ratio between effective discharge and mean streamflow) to the empirical exponent of the sediment rating curve and to the streamflow variability, resulting from climatic and landscape drivers. The analytic formulation predicts patterns of effective ratio versus streamflow variability observed in a set of catchments of the continental United States and helps in disentangling the major climatic and landscape drivers of sediment transport in rivers. The findings highlight larger effective ratios of erratic hydrologic regimes (characterized by high flow variability) compared to those exhibited by persistent regimes, which are attributable to intrinsically different streamflow dynamics. The framework provides support for the estimate of effective discharge in rivers belonging to diverse climatic areas.
Full Text Available Aircraft contrails develop into contrail cirrus by depositional growth and sedimentation of ice particles and horizontal spreading due to wind shear. Factors controlling this development include temperature, ice supersaturation, thickness of ice-supersaturated layers, and vertical gradients in the horizontal wind field. An analytical microphysical cloud model is presented and validated that captures these processes. Many individual contrail cirrus are simulated that develop differently owing to the variability in the controlling factors, resulting in large samples of cloud properties that are statistically analyzed. Contrail cirrus development is studied over the first four hours past formation, similar to the ages of line-shaped contrails that were tracked in satellite imagery on regional scales. On these time scales, contrail cirrus optical depth and microphysical variables exhibit a marked variability, expressed in terms of broad and skewed probability distribution functions. Simulated mean optical depths at a wavelength of 0.55 μm range from 0.05-0.5 and a substantial fraction 20-50% of contrail cirrus stay subvisible (optical depth <0.02, depending on meteorological conditions.
A detailed analysis based on an observational case study over the continental USA suggests that previous satellite measurements of line-shaped persistent contrails have missed about 89%, 50%, and 11% of contrails with optical depths 0-0.05, 0.05-0.1, and 0.1-0.2, respectively, amounting to 65% of contrail coverage of all optical depths. When comparing observations with simulations and when estimating the contrail cirrus climate impact, not only mean values but also the variability in optical depth and microphysical properties need to be considered.
Full Text Available Aircraft contrails develop into contrail cirrus by depositional growth and sedimentation of ice particles and horizontal spreading due to wind shear. Factors controlling this development include temperature, ice supersaturation, thickness of ice-supersaturated layers, and vertical gradients in the horizontal wind field. An analytical microphysical cloud model is presented and validated that captures these processes. Many individual contrail cirrus are simulated that develop differently owing to the variability in the controlling factors, resulting in large samples of cloud properties that are statistically analyzed. Contrail cirrus development is studied over the first four hours past formation, similar to the ages of contrails that were tracked in satellite imagery on regional scales. On these time scales, contrail cirrus optical depth and microphysical variables exhibit a marked variability, expressed in terms of broad and skewed probability distribution functions. Typical simulated mean optical depths at a wavelength of 0.55 μm are in the range 0.2–0.3. A substantial fraction 20–40% of contrail cirrus stay subvisible (optical depth <0.02. A detailed analysis suggests that previous satellite measurements of line-shaped persistent contrails have missed about 86% (35% of contrails with optical depth ≤0.05 (0.05–0.1, amounting to almost 50% of contrails of all optical depths. When comparing observations with simulations and when estimating the contrail cirrus climate impact, not only mean values but also the variability in optical depth and microphysical properties need to be considered.
Nola, F. J.
Three-Phase Power-Factor Controller develops a control signal for each motor winding. As motor loading decreases, rms value of applied voltage is decreased by feedback-control circuit. Power consumption is therefore lower than in unregulated operation. Controller employs phase detector for each of three phases of delta-connected induction motor. Phase-difference sum is basis for control.
李晓东; 王在文; 侯章栓
In this paper, we displayed one-dimensional climate signals, such as global temperature variation, Southern Oscillation Index and variation of external forcing factors, on a two-dimensional time-scale plane using compactly supported wavelet decomposition. Using the lag-correlation analysis method, and interpretative variance analysis method, and phase comparison method to the wavelet analysis result, we not only gained the variation on different scales to the global temperature and El Nino signals, the location of the jump point and intrinsic scale of these series, but also indicated the magnitude, extent and time of the effect of external forcing factors on them. We also put forward reasonable explanation to the main variation of recent 140 years.
Lichty, R.W.; Karlinger, M.R.
A climate factor, CT, (T = 2-, 25-, and 100-year recurrence intervals) that delineates regional trends in small-basin flood frequency was derived using data from 71 long-term rainfall record sites. Values of CT at these sites were developed by a regression analysis that related rainfall-runoff model estimates of T-year floods to a sample set of 50 model calibrations. CT was regionalized via kriging to develop maps depicting its geographic variation for a large part of the United States east of the 105th meridian. Kriged estimates of CT and basin-runoff characteristics were used to compute regionalized T-year floods for 200 small drainage basins. Observed T-year flood estimates also were developed for these sites. Regionalized floods are shown to account for a large percentage of the variability in observed flood estimates with coefficients of determination ranging from 0.89 for 2-year floods to 0.82 for 100-year floods. The relative importance of the factors comprising regionalized flood estimates is evaluated in terms of scale (size of drainage area), basin-runoff characteristics (rainfall-runoff model parameters), and climate (CT).
Udink ten Cate, A.J.
The material presented in this thesis can be grouped around four themes, system concepts, modeling, control and adaptive control. In this summary these themes will be treated separately.System conceptsIn Chapters 1 and 2 an overview of the problem formulation is presented. It is suggested that there
Trees at Alaskan treelines are assumed to be limited by temperature and to expand upslope and/or to higher latitudes with global warming. However, recent studies describe negative temperature responses and drought stress of Alaskan treeline trees in recent decades. In this study, we have analyzed the responses of treeline white spruce to temperature and precipitation according to different climatic regimes in Alaska, described as negative (cool) and positive (warm) phases of the Pacific Decadal Oscillation (PDO). We found that in three consecutive phases (positive from 1925–46, negative from 1947–76, and positive again from 1977–98), the growth responses to temperature and precipitation differed markedly. Before 1947, in a phase of warm winters and with summer temperatures being close to the century mean, the trees at most sites responded positively to summer temperature, as one would expect from treeline trees at northern high latitudes. Between 1947 and 1976, a phase of cold winters and average summers, the trees showed similar responses, but a new pattern of negative responses to the summer temperature of the year prior to growth coupled with positive responses to the precipitation in the same year emerged at some sites. As the precipitation was relatively low at those sites, we assume that drought stress might have played a role. However, the climate responses were not uniform but were modified by regional gradients (trees at northern sites responded more often to temperature than trees at southern sites) and local site conditions (forest trees responded more often to precipitation than treeline trees), possibly reflecting differences in energy and water balance across regions and sites, respectively. However, since the shift in the PDO in 1976 from a negative to a positive phase, the trees’ climate–growth responses are much less pronounced and climate seems to have lost its importance as a limiting factor for the growth of treeline white spruce. If
Chen, X.; Bohn, T. J; Lettenmaier, D. P.
Climate factors including soil temperature and moisture, incident solar radiation, and atmospheric carbon dioxide concentration are important environmental controls on methane (CH4) emissions from northern wetlands. We investigated the spatiotemporal distributions of the influence of these factors on northern high-latitude wetland CH4 emissions using an enhanced version of the Variable Infiltration Capacity (VIC) land surface model. We simulated CH4 emissions from wetlands a...
Chen, X.; Bohn, T. J; Lettenmaier, D. P.
Climate factors including soil temperature and moisture, incident solar radiation, and atmospheric carbon dioxide concentration are important environmental controls on methane (CH4) emissions from northern wetlands. We investigated the spatio-temporal distributions of the influence of these factors on northern high latitude wetland CH4 emissions using an enhanced version of the Variable Infiltration Capacity (VIC) land surface model. We simulated CH4 emissio...
The aim of this thesis is to study how genes are switched on and off in a coordinated way across an entire genome. In order to do this yeast is used as a model organism. The mechanisms that control gene expression in yeast are very similar to those of human cells. Chapter 1 provides a general introd
Full Text Available Safety issues have always been put forward as one of the major problems and primary concerns in construction industries in many countries. This paper will focus on the impact of safety training on safety climate and its relevant factors in two sites of a construction firm. The Health and Safety Executive (HSE guide to safety climate tool that had been validated in Iran was used to determine the impacts of safety training on safety climate and its relevant factors. For this purpose, 347 workers filled out the questionnaire before and after safety training. The relationships between demographic features of workers and safety climate factors were considered in the questionnaire. Spearman's rho test was used to determine the relationship between safety climate factors. In both sites, there were significant differences (p<0.05 between safety climate factors before and after safety training while, the level of safety climate in both sites was the same before (p=0.416 and after (p=0.547 safety training. The results of Spearman's correlations test indicated that there has been a significant relationship (p<0.05 between safety climate and its relevant factors in both sites. The results showed that some safety climate factors such as pressure for production had been influenced by demographic factors such as age and job category. Safety training can improve the level of safety climate and its relevant factors in a construction industry. Improvement of each safety climate factor can promote the level of safety climate. Demographic features affected safety climate level and its relevant factors.
San Giacomo, Rose-Marie Carla
The purpose of this study was to investigate the overall satisfaction with organizational climate factors across seven studies of various levels of community college personnel. A secondary purpose was to determine if there was a significant relationship between satisfaction with organizational climate factors and the importance of job satisfaction…
N. O. Anyoha
Full Text Available The aim of the study was to determine the socioeconomic factors influencing climate change adaptation among crop farmers in Umuahia South Area of Abia State, Nigeria. The specific objectives of the study were to determine socioeconomic characteristics of crop farmers in the area, determine farmers level of awareness of climate change in the area, ascertain effects of climate change in crop production, identify adaptation strategies adopted by the farmers in the area and determine socioeconomic factors influencing adaptation to climate change. Data were collected through a questionnaire distributed to 120 farmers. Data were analyzed using descriptive statistical tools such as tables, likert type scale and multiple regression analysis. Results of data collected shows that the strategies adopted to combat the effects of climate change by farmers in the area include tree planting, cultivation of early maturing crops, mixed farming, use of improved crop varieties, increased use of family labour, engagement in complementary/diverse livelihoods, cover cropping, changes in planting and harvesting dates, irrigation practices, crop rotation, riverside/bank cultivation, increased frequency of weeding etc, Results reveal that farm size, farming experience, household size, and social organization (MEM COP were significant at 5%, sex was significant at 1% . Extension educational campaign should be intensified to increase the knowledge about climate change. Government should collaborate with meteorologists in forecasting about climate change and also in bringing about measures to control the adverse effect of climate change especially in agriculture.
Jurkovic, A.; Lipa, W.; Adler, S.; Albenberger, J.; Lechner, W.; Swietli, R.; Vossberg, I.; Zehetner, S.
Checked climate datasets are a "conditio sine qua non" for all projects that are relevant for environment and climate. In the framework of climate change studies and analysis it is essential to work with quality controlled and trustful data. Furthermore these datasets are used as input for various simulation models. In regard to investigations of extreme events, like strong precipitation periods, drought periods and similar ones we need climate data in high temporal resolution (at least in daily resolution). Because of the historical background - during Second World War the majority of our climate sheets were sent to Berlin, where the historical sheets were destroyed by a bomb attack and so important information got lost - only several climate sheets, mostly duplicates, before 1939 are available and stored in our climate data archive. In 1970 the Central Institute for Meteorology and Geodynamics in Vienna started a first attempt to digitize climate data by means of punch cards. With the introduction of a routinely climate data quality control in 1984 we can speak of high-class-checked daily data (finally checked data, quality flag 6). Our group is working on the processing of digitization and quality control of the historical data for the period 1872 to 1983 for 18 years. Since 2007 it was possible to intensify the work (processes) in the framework of an internal project, namely Austrian Climate Data Rescue and Quality Control. The aim of this initiative was - and still is - to supply daily data in an outstanding good and uniform quality. So this project is a kind of pre-project for all scientific projects which are working with daily data. In addition to routine quality checks (that are running since 1984) using the commercial Bull Software we are testing our data with additional open source software, namely ProClim.db. By the use of this spatial and statistical test procedure, the elements air temperature and precipitation - for several sites in Carinthia - could
Doetterl, Sebastian; Stevens, Antoine; Six, Johan; Merckx, Roel; Van Oost, Kristof; Casanova Pinto, Manuel; Casanova-Katny, Angélica; Muñoz, Cristina; Boudin, Mathieu; Zagal Venegas, Erick; Boeckx, Pascal
Climatic and geochemical parameters are regarded as the primary controls for soil organic carbon (SOC) storage and turnover. However, due to the difference in scale between climate and geochemical-related soil research, the interaction of these key factors for SOC dynamics have rarely been assessed. Across a large geochemical and climatic transect in similar biomes in Chile and the Antarctic Peninsula we show how abiotic geochemical soil features describing soil mineralogy and weathering pose a direct control on SOC stocks, concentration and turnover and are central to explaining soil C dynamics at larger scales. Precipitation and temperature had an only indirect control by regulating geochemistry. Soils with high SOC content have low specific potential CO2 respiration rates, but a large fraction of SOC that is stabilized via organo-mineral interactions. The opposite was observed for soils with low SOC content. The observed differences for topsoil SOC stocks along this transect of similar biomes but differing geo-climatic site conditions are of the same magnitude as differences observed for topsoil SOC stocks across all major global biomes. Using precipitation and a set of abiotic geochemical parameters describing soil mineralogy and weathering status led to predictions of high accuracy (R2 0.53-0.94) for different C response variables. Partial correlation analyses revealed that the strength of the correlation between climatic predictors and SOC response variables decreased by 51 - 83% when controlling for geochemical predictors. In contrast, controlling for climatic variables did not result in a strong decrease in the strength of the correlations of between most geochemical variables and SOC response variables. In summary, geochemical parameters describing soil mineralogy and weathering were found to be essential for accurate predictions of SOC stocks and potential CO2 respiration, while climatic factors were of minor importance as a direct control, but are
The main objective of this research is to design an efficient control system for the indoor climate of a large-scale partition-less livestock building, in order to maintain a healthy, comfortable and economically energy consuming indoor environment for the agricultural animals and farmers. In this...... resilience of the control system to disturbances beyond its bandwidth, increases the manipulators utilization efficiency, and reduces energy consumption by solving a constrained convex optimization. Through comparative simulation results analysis, the proposed modeling and control technique is proved to be...... scale livestock buildings, and could be considered as an alternative solution to the current used decentralized PID controller....
Zeng, Ruijie; Cai, Ximing
Knowledge of the temporal variability of evapotranspiration (ET) is fundamental to a comprehensive understanding of hydroclimatologic processes under a changing climate and anthropogenic interferences. This study applies a variance decomposition framework to assessing ET interannual and intra-annual variance in 32 large river basins. It is found that climate (precipitation and potential ET) and terrestrial storage play different roles in ET variance with different time scales. At the interannual scale, ET variance is primarily controlled by climatic variability and dampened/enhanced by terrestrial storage change. At the intra-annual scale, the sources of ET variance exhibit a geographic pattern: ET variance is controlled by terrestrial storage change in Middle Asia, by seasonality in the Indian monsoon region, by precipitation and terrestrial storage in low altitude arid regions, and by potential ET and terrestrial storage in boreal regions. Quantifying the components of ET variability will help scientists understand the factors on ET processes under various natural and anthropogenic conditions.
This study presents an alternative method of estimating wood production at regional/global levels from tropical plantations based on climatic variables. A generic model for estimating potential yield in tropical plantations was formulated. The model was developed for teak (Tectona grandis L. F.) as a case study. Available data of teak sample plots from India, Myanmar, Indonesia, Nigeria and Ivory Coast, consisting of 153 plots distributed over 38 meteorological stations were used. A new base age invariant site index function was developed and the site index of each plot was estimated. The mean annual volume increment (MAI) of each plot from existing yield tables was then interpolated. Treating MAI at 50 years (rotation age) as potential yield of teak, a model was constructed which could explain about 59% variance of the potential yield. Models constructed for estimating the maximum MAI and the site index of teak explained the variability up to 61% and 57% respectively. The models underestimated the productivity of teak in Indonesia, Nigeria and Ivory Coast. The rainfall and the relative humidity have been identified as the most important climatic variables influencing the growth of teak. The length of the growing season and the temperature of the warmest month of the growing season were found significant in the models. The temperature and the day length (sunshine) have not been found to be the limiting factors for the growth of teak. However, the maximum temperature beyond a certain upper limit has a negative effect on growth. The study indicates that this upper limit is around 33 deg C for teak. The models could be used to forecast the potential yield of the existing as well as planned teak plantations in the tropical region. 109 refs, 15 figs, 11 tabs
Menny, Claas; Osberghaus, Daniel; Pohl, Max; Werner, Ute
In two empirical surveys in Germany the link between the information respondents have about climate change and their risk perception of the phenomenon was analysed. We found that a better understanding of the effects of climate change might lead to a decrease of the perceived hazard. In contrast, a high self-declared knowledge about climate change might correspond with higher risk perception. Further factors affecting the risk perception of climate change are gender, experience of extreme wea...
Pčolka, M.; Žáčeková, E.; Robinett, R.; Čelikovský, Sergej; Šebek, M.
Portland: IEEE, 2014, s. 418-423. (CFP14ACC-USB). ISBN 978-1-4799-3271-9. ISSN 0743-1619. [The 2014 American Control Conference (ACC‘14). Portland, Oregon (US), 04.06.2014-06.06.2014] R&D Projects: GA ČR GA13-20433S Grant ostatní: GA ČR(CZ) GC13-12726J Institutional support: RVO:67985556 Keywords : Model predictive control * optimization Subject RIV: BC - Control Systems Theory
Nola, F. J.
Positive feedback assures reliable switching. Three Phase Power Factor Controller includes three phase detectors, each produces rectangular waves of duration approximately equal to lag time between line voltage and motor current.
Shen, Y.; Koh, TY; Rowlinson, SM; Bridge, AJ
Employees’ safety climate perceptions dictate their safety behavior because individuals act based on their perceptions of reality. Extensive empirical research in applied psychology has confirmed this relationship. However, rare efforts have been made to investigate the factors contributing to a favorable safety climate in construction research. As an initial effort to address the knowledge gap, this paper examines factors contributing to a psychological safety climate, an operationalization ...
Guillaume Constantin de Magny
Full Text Available Cholera is an acute diarrheal illness caused by Vibrio cholerae and occurs as widespread epidemics in Africa. In 2005, there were 31,719 cholera cases, with 458 deaths in the Republic of Senegal. We retrospectively investigated the climate origin of the devastating floods in mid-August 2005, in the Dakar Region of Senegal and the subsequent outbreak of cholera along with the pattern of cholera outbreaks in three other regions of that country. We compared rainfall patterns between 2002 and 2005 and the relationship between the sea surface temperature (SST gradient in the tropical Atlantic Ocean and precipitation over Senegal for 2005. Results showed a specific pattern of rainfall throughout the Dakar region during August, 2005, and the associated rainfall anomaly coincided with an exacerbation of the cholera epidemic. Comparison of rainfall and epidemiological patterns revealed that the temporal dynamics of precipitation, which was abrupt and heavy, was presumably the determining factor. Analysis of the SST gradient showed that the Atlantic Ocean SST variability in 2005 differed from that of 2002 to 2004, a result of a prominent Atlantic meridional mode. The influence of this intense precipitation on cholera transmission over a densely populated and crowded region was detectable for both Dakar and Thiès, Senegal. Thus, high resolution rainfall forecasts at subseasonal time scales should provide a way forward for an early warning system in Africa for cholera and, thereby, trigger epidemic preparedness. Clearly, attention must be paid to both natural and human induced environmental factors to devise appropriate action to prevent cholera and other waterborne disease epidemics in the region.
Constantin de Magny, Guillaume; Thiaw, Wassila; Kumar, Vadlamani; Manga, Noël M.; Diop, Bernard M.; Gueye, Lamine; Kamara, Mamina; Roche, Benjamin; Murtugudde, Raghu; Colwell, Rita R.
Cholera is an acute diarrheal illness caused by Vibrio cholerae and occurs as widespread epidemics in Africa. In 2005, there were 31,719 cholera cases, with 458 deaths in the Republic of Senegal. We retrospectively investigated the climate origin of the devastating floods in mid-August 2005, in the Dakar Region of Senegal and the subsequent outbreak of cholera along with the pattern of cholera outbreaks in three other regions of that country. We compared rainfall patterns between 2002 and 2005 and the relationship between the sea surface temperature (SST) gradient in the tropical Atlantic Ocean and precipitation over Senegal for 2005. Results showed a specific pattern of rainfall throughout the Dakar region during August, 2005, and the associated rainfall anomaly coincided with an exacerbation of the cholera epidemic. Comparison of rainfall and epidemiological patterns revealed that the temporal dynamics of precipitation, which was abrupt and heavy, was presumably the determining factor. Analysis of the SST gradient showed that the Atlantic Ocean SST variability in 2005 differed from that of 2002 to 2004, a result of a prominent Atlantic meridional mode. The influence of this intense precipitation on cholera transmission over a densely populated and crowded region was detectable for both Dakar and Thiès, Senegal. Thus, high resolution rainfall forecasts at subseasonal time scales should provide a way forward for an early warning system in Africa for cholera and, thereby, trigger epidemic preparedness. Clearly, attention must be paid to both natural and human induced environmental factors to devise appropriate action to prevent cholera and other waterborne disease epidemics in the region. PMID:22952995
Gregersen, Ida Bülow; Madsen, H.; Arnbjerg-Nielsen, Karsten
The application of climate factors has become more common in urban drainage design. The climate factor accounts for the expected increase in the magnitude of the extreme rainfall events during the technical lifetime of the drainage system. The present practice in Denmark is the application of cli...
The objective factor 4 is the division by four of the greenhouse gases emission. This colloquium aims to define possible actions to reach this objective. The first part concerns presentations of personalities of the domain and offers an international panorama of the energetic and environmental policies, against the climatic change and how to reconcile economic growth with climatic change. The second part wonders on the mobilization of the actors secton a national and international framework. (A.L.B.)
New human-system interface technologies provide opportunities for improving operator and plant performance. However, if these technologies are not properly implemented, they may introduce new challenges to performance and safety. This paper reports the results from a survey of human factors considerations that arise in the implementation of advanced human-system interface technologies in process control and other complex systems. General trends were identified for several areas based on a review of technical literature and a combination of interviews and site visits with process control organizations. Human factors considerations are discussed for two of these areas, automation and controls
Full Text Available Power factor improvement is the essence of any power sector for reliable operation. This paper provides Thyristor Controlled Reactor regulated by programmed microcontroller which aids in improving power factor and retaining it close to unity under various loading conditions. The implementation is done on 8051 microcontrollerwhich isprogrammed using Keil software. To determine time lag between current and voltage PSpice softwareis used and to display power factor according tothe variation in loadProteus software is used. Whenever a capacitive load is connected to the transmission linea shunt reactor is connected which injects lagging reactive VARs to the power system. As a result the power factor is improved. The results given in this paper provides suitable microcontroller based reactive power compensation and power factor improvement technique using a Thyristor Controlled Reactor module.
Waller, Eric Kindseth
A better understanding of the environmental controls on current plant species distribution is essential if the impacts of such diverse challenges as invasive species, changing fire regimes, and global climate change are to be predicted and important diversity conserved. Climate, soil, hydrology, various biotic factors fire, history, and chance can all play a role, but disentangling these factors is a daunting task. Increasingly sophisticated statistical models relying on existing distributions and mapped climatic variables, among others, have been developed to try to answer these questions. Any failure to explain pattern with existing mapped climatic variables is often taken as a referendum on climate as a whole, rather than on the limitations of the particular maps or models. Every location has a unique and constantly changing climate so that any distribution could be explained by some aspect of climate. Chapter 1 of this dissertation reviews some of the major flaws in species distribution modeling and addresses concerns that climate may therefore not be predictive of, or even relevant to, species distributions. Despite problems with climate-based models, climate and climate-derived variables still have substantial merit for explaining species distribution patterns. Additional generation of relevant climate variables and improvements in other climate and climate-derived variables are still needed to demonstrate this more effectively. Satellite data have a long history of being used for vegetation mapping and even species distribution mapping. They have great potential for being used for additional climatic information, and for improved mapping of other climate and climate-derived variables. Improving the characterization of cloud cover frequency with satellite data is one way in which the mapping of important climate and climate-derived variables can be improved. An important input to water balance models, solar radiation maps could be vastly improved with a
Understanding the relationships between climate and carbon exchange by terrestrial ecosystems is critical to predict future levels of atmospheric carbon dioxide because of the potential accelerating effects of positive climate-carbon cycle feedbacks. However, directly observed relationships between climate and terrestrial CO2 exchange with the atmosphere across biomes and continents are lacking. Here we present data describing the relationships between net ecosystem exchange of carbon (NEE) and climate factors as measured using the eddy covariance method at 125 unique sites in various ecosystems over six continents with a total of 559 site-years. We find that NEE observed at eddy covariance sites is (1) a strong function of mean annual temperature at mid- and high-latitudes, (2) a strong function of dryness at mid- and low-latitudes, and (3) a function of both temperature and dryness around the mid-latitudinal belt (45 deg. N). The sensitivity of NEE to mean annual temperature breaks down at ∼ 16 deg. C (a threshold value of mean annual temperature), above which no further increase of CO2 uptake with temperature was observed and dryness influence overrules temperature influence.
Ek, Åsa; Akselsson, Roland; Arvidsson, Marcus; Johansson, Curt R
Due to organizational changes in the Swedish air navigation services (ANS), which in extension could impact flight safety, the safety culture (SC), organizational climate (OC), and related areas are monitored. Study locations are the two main air traffic control centers in Sweden and parts of the central ANS office. This paper reports on a first attempt to investigate whether relationships exist between SC and OC. The findings show that such relationships exist.
Labrie, C.W.; Zwart, de, H.F.
Like in most countries, in the Netherlands energy consumption is an increasing cost component. In cut flowers grown at a relatively low temperature, most of the energy is used for dehumidification. In Alstroemeria dehumidification is especially important to prevent the physiological disorder expressed as necrotic leaf tips. Research has been carried out showing that improved climate control can save 37% on heating, without a reduction on yield and even a quality, compared to a contemporary re...
Full Text Available A software to simulate the dynamic operation of climate control system for a generic automobile has been developed. The transient nature of passenger cabin temperature and relative humidity are predicted using the principles of thermodynamics. Analysis include detailed simulations of every component of the automobile air conditioning network. The methodology is validated by comparing the simulation results with the experimental results.
Muñoz-Rojas, Miriam; Erickson, Todd E.; Martini, Dylan C.; Dixon, Kingsley W.; Merritt, David J.
Land degradation affects 10-20 % of drylands globally. Intensive land use and management, large-scale disturbances such as extractive operations, and global climate change, have contributed to degradation of these systems worldwide. Restoring these damaged environments is critical to improving ecosystem services and functions, conserve biodiversity, and contribute to climate resilience, food security, and landscape sustainability. Here, we present a case study on plant species of the mining intensive semi-arid Pilbara region in Western Australia that examines the effects of climate and soil factors on the restoration of drylands. We analysed the effects of a range of rainfall and temperature scenarios and the use of alternative soil materials on seedling recruitment of key native plant species from this area. Experimental studies were conducted in controlled environment facilities where conditions simulated those found in the Pilbara. Soil from topsoil (T) stockpiles and waste materials (W) from an active mine site were mixed at different proportions (100 % T, 100 % W, and two mixes of topsoil and waste at 50 : 50 and 25 : 75 ratios) and used as growth media. Our results showed that seedling recruitment was highly dependent on soil moisture and emergence was generally higher in the topsoil, which had the highest available water content. In general, responses to the climate scenarios differed significantly among the native species which suggest that future climate scenarios of increasing drought might affect not only seedling recruitment but also diversity and structure of native plant communities. The use of waste materials from mining operations as growth media could be an alternative to the limited topsoil. However, in the early stages of plant establishment successful seedling recruitment can be challenging in the absence of water. These limitations could be overcome by using soil amendments but the cost associated to these solutions at large landscape scales
Dust storms occurring in arid and semi-arid regions play a main role in the evolution of landscapes. Climate is generally regarded to be important factors influencing the occurrence of dust storm, however, the way of climate controlling dust storms had been poorly understood. In this paper, we present the Ew Index model to describe the relationship between climate variables and dust storm frequency using the available meteorological data from three meteorological stations in Maowusu Desert. This index model explains 96.8%, 69.8% and 65.3% of the variance of dust storm frequency in three regions from the north to the south,respectively and this difference is probably caused by the difference of the human disturbance. The Ew Index model is an effective predictor of dust storm frequency and provides us a quite good understanding on the occurrence of dust storms in Maowusu Desert.
Kelly, A. E.; Goulden, M. L.
The broad climate gradient of the slopes of the western Sierra Nevada mountains supports ecosystems spanning extremes of productivity, biomass, and function. We are using this natural environmental gradient to understand how climate controls NPP, aboveground biomass, species' range limits, and phenology. Our experimental approach combines eddy covariance, sap flow, dendrometer, and litterfall measurements in combination with soil and hydrological data from the Southern Sierra Critical Zone Observatory (SSCZO). We have found that above about 2500 m, forest productivity is limited by winter cold, while below 1200 m, productivity is likely limited by summer drought. The sweet spot between these elevations has a nearly year-long growing season despite a snowpack that persists for as long as six months. Our results show that small differences in temperature can markedly alter the water balance and productivity of mixed conifer forests.
Full Text Available With global climate changes intensifying, the hydrological response to climate changes has attracted more attentions. It is beneficial not only for hydrology and ecology but also for water resources planning and management to reveal the impacts of climate change on runoff. It is of great significance of climate elasticity of runoff to estimate the impacts of climatic factors on runoff. In addition, there are large spatial variations in climate type and geography characteristics over China. To get a better understanding the spatial variation of runoff response to climate variables change and detect the dominant climatic factor driving annual runoff change, we chose the climate elasticity method proposed by Yang and Yang (2011, where the impact of the catchment characteristics on runoff was represented by a parameter n. The results show that the dominant climatic factor driving annual runoff is precipitation in the most part of China, net radiation in the lower reach of Yangtze River Basin, the Pearl River Basin, the Huai River Basin and the southeast area, and wind speed in part of the northeast China.
Full Text Available BACKGROUND AND OBJECTIVES: Trachoma is the most common cause of infectious blindness. Hot, dry climates, dust and water scarcity are thought to be associated with the distribution of trachoma but the evidence is unclear. The aim of this study was to evaluate the epidemiological evidence regarding the extent to which climatic factors explain the current prevalence, distribution, and severity of acute and chronic trachoma. Understanding the present relationship between climate and trachoma could help inform current and future disease elimination. METHODS: A systematic review of peer-reviewed literature was conducted to identify observational studies which quantified an association between climate factors and acute or chronic trachoma and which met the inclusion and exclusion criteria. Studies that assessed the association between climate types and trachoma prevalence were also reviewed. RESULTS: Only eight of the 1751 papers retrieved met the inclusion criteria, all undertaken in Africa. Several papers reported an association between trachoma prevalence and altitude in highly endemic areas, providing some evidence of a role for temperature in the transmission of acute disease. A robust mapping study found strong evidence of an association between low rainfall and active trachoma. There is also consistent but weak evidence that the prevalence of trachoma is higher in savannah-type ecological zones. There were no studies on the effect of climate in low endemic areas, nor on the effect of dust on trachoma. CONCLUSION: Current evidence on the potential role of climate on trachoma distribution is limited, despite a wealth of anecdotal evidence. Temperature and rainfall appear to play a role in the transmission of acute trachoma, possibly mediated through reduced activity of flies at lower temperatures. Further research is needed on climate and other environmental and behavioural factors, particularly in arid and savannah areas. Many studies did not
Kyselý, Jan; Plavcová, Eva
Roč. 115, - (2010), D23118/1-D23118/14. ISSN 0148-0227 R&D Projects: GA ČR GAP209/10/2265 Grant ostatní: ENSEMBLES(XE) 505539; EURO4M(XE) 242093 Institutional research plan: CEZ:AV0Z30420517 Keywords : daily air temperature * interpolation * gridded data * regional climate models * control climate * Europe Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 3.303, year: 2010
Full Text Available Currently there is a lack of quantitative information regarding the driving factors of vegetation dynamics in post-Soviet Central Asia. Insufficient knowledge also exists concerning vegetation variability across sub-humid to arid climatic gradients as well as vegetation response to different land uses, from natural rangelands to intensively irrigated croplands. In this study, we analyzed the environmental drivers of vegetation dynamics in five Central Asian countries by coupling key vegetation parameter “overall greenness” derived from Moderate Resolution Imaging Spectroradiometer (MODIS Normalized Difference Vegetation Index (NDVI time series data, with its possible factors across various management and climatic gradients. We developed nine generalized least-squares random effect (GLS-RE models to analyze the relative impact of environmental factors on vegetation dynamics. The obtained results quantitatively indicated the extensive control of climatic factors on managed and unmanaged vegetation cover across Central Asia. The most diverse vegetation dynamics response to climatic variables was observed for “intensively managed irrigated croplands”. Almost no differences in response to these variables were detected for managed non-irrigated vegetation and unmanaged (natural vegetation across all countries. Natural vegetation and rainfed non-irrigated crop dynamics were principally associated with temperature and precipitation parameters. Variables related to temperature had the greatest relative effect on irrigated croplands and on vegetation cover within the mountainous zone. Further research should focus on incorporating the socio-economic factors discussed here in a similar analysis.
Cope, Shannon F.; Ungar, Wendy J.; Glazier, Richard H.
Summary Objectives The objective of this study was to evaluate the association between socioeconomic factors and asthma control in children, as defined by the Canadian Pediatric Asthma Consensus Guidelines. Patients and Methods Cross-sectional data from a completed study of 879 asthmatic children between the ages of 1 and 18 residing in the Greater Toronto Area were used. The database included data on demographics, health status, asthma control, and health-related quality of life. Stepwise forward modeling multiple regression was used to investigate the impact of socioeconomic status on asthma control, based on six control parameters from the 2003 Canadian Pediatric Asthma Consensus Guidelines. Results Only 11% of patients met the requirements for acceptable control, while 20% had intermediate control, and 69% had unacceptable asthma control. Children from families in lower income adequacy levels had poorer control. Conclusions Disparities in asthma control between children from families of different socio-economic strata persist, even with adjustment for utilization of primary care services and use of controller medications. PMID:18615669
Mastepanov, M.; Sigsgaard, Charlotte; Tagesson, Håkan Torbern;
known factors controlling methane emission, i.e. temperature and water table position. Late in the growing season CH4 emissions were found to be very similar between the study years (except the extremely dry 2010) despite large differences in climatic factors (temperature and water table). Late......The northern latitudes are experiencing disproportionate warming relative to the mid-latitudes, and there is growing concern about feedbacks between this warming and methane production and release from high-latitude soils. Studies of methane emissions carried out in the Arctic, particularly those......-in periods. The measurements show clear seasonal dynamics in methane emission. The start of the growing season and the increase in CH4 fluxes were strongly related to the date of snowmelt. Within each particular growing season, CH4 fluxes were highly correlated with the soil temperature (R-2 > 0.75), which...
The thesis consists of two parts. The first part is a general part about predictive control in the indoor climate field. The second part deals with the control system implementation in the passive indoor climate system. The fundamentals, general principles and mechanisms of the class of predictive controllers and control strategies with a linear objective function are described in chapter 2. Chapter 3 deals with the typical characteristics of the indoor and outdoor climate, that have to be incorporated in a predictive control system to make it a successful and robust predictive indoor climate control system. A general scheme for a predictive indoor climate system, that has self-learning features, is described in Chapter 4. Chapter 5 introduces the passive indoor climate system to which a predictive control strategy is applied. Finally, in Chapter 6, a test facility for passive climate systems, referred to as the TU Delft test cell, is described.
Grayson, Jessica L.; Alvarez, Heather K.
The present study investigated components of school climate (i.e. parent/community relations, administration, student behavioral values) and assessed their influence on the core burnout dimensions of Emotional Exhaustion, Depersonalization, and feelings of low Personal Accomplishment. The study weighed the relative contributions of demographic…
Gao, Zhiqiang; Gao, Wei; Slusser, James R.; Pan, Xiaoling; Ma, Yingjun
The continuing rise in atmospheric CO2 is considered as a main cause of the future changes in global climate. Predicted climate changes include an increase in mean annual air temperature and alterations in precipitation pattern and cloud cover. Net primary productivity (NPP) measures products of major economic and social importance, such as agricultural crop yield and forest production. It is important to understand the response of vegetation to the possible climate changes. While the Global NPP is hard to be measured directly, its global spatial and temporal dynamics can be investigated by a combination of ecosystem process modeling and monitoring by remote sensing (RS). NPP has been linked to climatic patterns by approaches ranging from simple correlations to sophisticated simulation models. This study was conducted in a range where the productivity and climate exist along an east-west transect in northern China. We used modified Common Land Surface Model (CLM) to simulate the NPP combined with satellite data and assessed the response of NPP under different climate change controls with different land surface vegetation types in study areas. The feasibility of the CLM model was tested and parameterized based on the ecological characteristics. The response of NPP to increased temperature was more sensitive to the doubled CO2 climate because the temperature is the limited factor to vegetation growth in study areas. The responses of NPP to different climate controls were also influenced by different vegetation types and ecological characteristics.
Valtanen, Marjo; Sillanpää, Nora; Setälä, Heikki
Urban runoff contains various pollutants and has the potential of deteriorating the quality of aquatic ecosystems. In this study our objective is to shed light on the factors that control the runoff water quality in urbanized catchments. The effects of runoff event characteristics, land use type and catchment imperviousness on event mass loads (EML) and event mean concentrations (EMC) were studied during warm and cold periods in three study catchments (6.1, 6.5 and 12.6 ha in size) in the city of Lahti, Finland. Runoff and rainfall were measured continuously for two years at each catchment. Runoff samples were taken for total nutrients (tot-P and tot-N), total suspended solids (TSS), heavy metals (Zn, Cr, Al, Co, Ni, Cu, Pb, Mn) and total organic carbon (TOC). Stepwise multiple linear regression analysis (SMLR) was used to identify general relationships between the following variables: event water quality, runoff event characteristics and catchment characteristics. In general, the studied variables explained 50-90% of the EMLs but only 30-60% of the EMCs, with runoff duration having an important role in most of the SMLR models. Mean runoff intensity or peak flow was also often included in the runoff quality models. Yet, the importance (being the first, second or third best) and role (negative or positive impact) of the explanatory variables varied between the cold and warm period. Land use type often explained cold period concentrations, but imperviousness alone explained EMCs weakly. As for EMLs, the influence of imperviousness and/or land use was season and pollutant dependent. The study suggests that pollutant loads can be - throughout the year - adequately predicted by runoff characteristics given that seasonal differences are taken into account. Although pollutant concentrations were sensitive to variation in seasonal and catchment conditions as well, the accurate estimation of EMCs would require a more complete set of explanatory factors than used in this
Dorman, L.; Dai, U.; Kafri, A.; Pustil'nik, L.; Sternlieb, A.
We consider possible effects of cosmic rays and some other space factors on the Earth's climate change. It is well known that the system of internal and external factors formatting the climate is very unstable; decreasing planetary temperature leads to an increase of snow surface, and decreasing of the total solar energy input into the system decreases the planetary temperature even more, etc. From this it follows that even energetically small factors acted long time may have a big influence on climate change. In our opinion, the most important of these factors are cosmic rays (CR) and space dust through their influence on formation of clouds, and thus, on climate. Are important also some rarely phenomena as impacts of asteroids and nearby supernova explosions.
Macel, M.; Lawson, C.S.; Mortimer, S.R.; Smilauerova, M.; Bischoff, A.; Crémieux, L.; Dolezal, J.; Edwards, A.R.; Lanta, V.; Bezemer, T.M.; Putten, van der W.H.; Igual, J.M.; Rodriguez-Barrueco, C.; Müller-Schärer, H.; Steinger, T.
Evolutionary theory suggests that divergent natural selection in heterogeneous environments can result in locally adapted plant genotypes. To understand local adaptation it is important to study the ecological factors responsible for divergent selection. At a continental scale, variation in climate
Hameed, Ibrahim; El-Madbouly, E I; Abdo, M I
Modern greenhouses are equipped with different components for providing a comfortable climate for plant growth. A component malfunction may result in loss of production. Therefore, it is desirable to design a control system, which is stable, and is able to provide an acceptable degraded performance...... even in the faulty case. In this paper, an active fault tolerant control scheme to compensate for actuator and/or sensor faults in the greenhouse climate system is designed. The control system consists of a sensitive and reliable Fault Detection and Diagnosis (FDD) mechanism for different types of...... faults in presence of system disturbances and a robust reconfigurable control design based on fault-hiding principal in which the fault is hidden from the nominal controller and the fault effects are compensated. In this approach, a set of virtual actuators and virtual sensors are used to guarantee the...
Iljins, Juris; Skvarciany, Viktorija; Gaile-Sarkane, Elīna
Purpose of the article: The purpose of this paper is to investigate the impact of organizational culture on organizational climate in process of change. For solving this problem, it is necessary to identify the main factors of organizational culture in the change process. After exploring the impact of organizational culture on organizational climate through distinguished culture’s factors, article examines how changes can be processed in different cultural environments. Methodology. The resea...
Huang, Zhongwei; Yang, Hanbo; Yang, Dawen
With global climate changes intensifying, the hydrological response to climate changes has attracted more attention. It is beneficial not only for hydrology and ecology but also for water resource planning and management to understand the impact of climate change on runoff. In addition, there are large spatial variations in climate type and geographic characteristics across China. To gain a better understanding of the spatial variation of the response of runoff to changes in climatic factors and to detect the dominant climatic factors driving changes in annual runoff, we chose the climate elasticity method proposed by Yang and Yang (2011). It is shown that, in most catchments of China, increasing air temperature and relative humidity have negative impacts on runoff, while declining net radiation and wind speed have positive impacts on runoff, which slow the overall decline in runoff. The dominant climatic factors driving annual runoff are precipitation in most parts of China, net radiation mainly in some catchments of southern China, air temperature and wind speed mainly in some catchments in northern China.
Kumar, S. Vinod
Plant growth and development are strongly affected by small differences in temperature. Current climate change has already altered global plant phenology and distribution, and projected increases in temperature pose a significant challenge to agriculture. Despite the important role of temperature on plant development, the underlying pathways are unknown. It has previously been shown that thermal acceleration of flowering is dependent on the florigen, FLOWERING LOCUS T (FT). How this occurs is, however, not understood, because the major pathway known to upregulate FT, the photoperiod pathway, is not required for thermal acceleration of flowering. Here we demonstrate a direct mechanism by which increasing temperature causes the bHLH transcription factor PHYTOCHROME INTERACTING FACTOR4 (PIF4) to activate FT. Our findings provide a new understanding of how plants control their timing of reproduction in response to temperature. Flowering time is an important trait in crops as well as affecting the life cycles of pollinator species. A molecular understanding of how temperature affects flowering will be important for mitigating the effects of climate change. © 2012 Macmillan Publishers Limited. All rights reserved.
LIHai-mei; HEXing-yuan; WANGKui-ling
Based on the data of stand investigation and stem analysis, the effects of climate factors on the poplar protection forest increment in the riverbank field of the Dalinghe and Xiaolinghe rivers of Liaoning Province, China were studied by stepwise regression procedure and grey system theories and methods. A regression model reflecting the correlation between the height increment of poplar protection forest and climatic factors was developed. The order of grey relevance for the effect of climatic factors on the height increment of poplar protection forest is" light>water>heat, and it could be interpreted that the poplar increment was mainly influenced by light factor, water factor, and heat factor. This result will provide scientific basis for the intensive cultivation and regeneration of the poplar protection forest in riverbank field in similar regions in China.
Bovy, Benoît; Braun, Jean; Demoulin, Alain
We present a new numerical framework for simulating short to long-term hillslope evolution. This modeling framework, to which we have given the name CLICHE (CLImate Control on Hillslope Evolution), aims to better capture the control of climate on soil dynamics. It allows the use of realistic forcing that involves, through a specific time discretization scheme, the variability of both the temperature and precipitation at time scales ranging from the daily rainfall events to the climatic oscillations of the Quaternary, also including seasonal variability. Two simple models of soil temperature and soil water balance permit the link between the climatic inputs and derived quantities that take part in the computation of the soil flux, such as the surface water discharge and the depth of the non-frozen soil layer. Using this framework together with a multi-process parameterization of soil transport, we apply an original method to calculate hillslope effective diffusivity as a function of climate. This allows us to demonstrate the ability of the model to simulate observed rates of hillslope erosion under different climates (cold and temperate) with a single set of parameter values. Numerical experiments furthermore suggest a potential high peak of sediment transport on hillslopes during the glacial-interglacial transitions of the Quaternary. We finally discuss the need to improve the parameterization of the soil production and transport processes in order to explicitly account for other key controlling factors that are also climate-sensitive, such as biological activity.
MohammadJavad Jafari; Mehdi Gharari; Mohtasham Ghafari; Leila Omidi; Saba Kalantari; GolamReza Asadolah-Fardi
Safety issues have always been put forward as one of the major problems and primary concerns in construction industries in many countries. This paper will focus on the impact of safety training on safety climate and its relevant factors in two sites of a construction firm. The Health and Safety Executive (HSE) guide to safety climate tool that had been validated in Iran was used to determine the impacts of safety training on safety climate and its relevant factors. For this purpose, 347 work...
Zhang, A P; Wei, R J; Xiong, H M; Wang, Z Y
Plague is an anthropozoonotic disease caused by the Yersinia pestis ,which developed by many factors including local climate factors. In recent years, more and more studies on the effects of climate on plague were conducted. According to the researches, climate factors (mainly the rainfall and temperature) affected the development and distribution of plague by influencing the abundance of plague host animals and fleas index. The climate also affected the epidemic dynamics and the scope of plague. There were significant differences existing in the influence of climate on the palgue developed in the north and south China. In the two different plague epidemic systems, the solitary Daurian ground squirrel-flea-plague and the social Mongolian gerbil-flea-plague, the obvious population differences existed among the responses of the host animal to the climate changes. Although the internal relationship between the rainfall, the flea index, the density of rodents and the plague supported the nutritional cascade hypothesis, it can not prove that there is a clear causality between the occurrence of plague and rainfall. So the influence of climate factors on plague distribution can only be used for early forecasting and warning of the plague. PMID:27141906
Zakaria M. Sawan
Full Text Available This study investigates the statistical relationship between climatic variables and aspects of cotton production (G. barbadense, and the effects of climatic factors prevailing prior to flowering or subsequent to boll setting on flower and boll production and retention in cotton. Also, the study covers the predicted effects of climatic factors during convenient intervals (in days on cotton flower and boll production compared with daily observation. Further, cotton flower and boll production as affected by climatic factors and soil moisture status has been considered. Evaporation, sunshine duration, relative humidity , surface soil temperature at 1800 h, and maximum air temperature are the important climatic factors that significantly affect flower and boll production. The least important variables were found to be surface soil temperature at 0600 h and minimum temperature. The five-day interval was found to be more adequately and sensibly related to yield parameters. Evaporation, minimum humidity and sunshine duration were the most effective climatic factors during preceding and succeeding periods on boll production and retention. There was a negative correlation between flower and boll production and either evaporation or sunshine duration, while that correlation with minimum relative humidity was positive. The soil moisture status showed low and in significant correlation with flower and boll production. Higher minimum relative humidity, short period of sunshine duration, and low temperatures enhanced flower and boll formation.
Phung, Dung; Huang, Cunrui; Rutherford, Shannon; Chu, Cordia; Wang, Xiaoming; Nguyen, Minh; Nguyen, Nga Huy; Manh, Cuong Do; Nguyen, Trung Hieu
The Mekong Delta is vulnerable to changes in climate and hydrological events which alter environmental conditions, resulting in increased risk of waterborne diseases. Research exploring the association between climate factors and diarrhoea, the most frequent waterborne disease in Mekong Delta region, is sparse. This study evaluated the climate-diarrhoea association in Can Tho city, a typical Mekong Delta area in Vietnam. Climate data (temperature, relative humidity, and rainfall) were obtained from the Southern Regional Hydro-Meteorological Centre, and weekly counts of diarrhoea visits were obtained from Can Tho Preventive Medicine Centre from 2004 to 2011. Analysis of climate and health variables was carried out using spline function to adjust for seasonal and long-term trends of variables. A distributed lag model was used to investigate possible delayed effects of climate variables on diarrhoea (considering 0-4 week lag periods), then the multivariate Poisson regression was used to examine any potential association between climate factors and diarrhoea. The results indicated that the diarrhoea incidence peaked within the period August-October annually. Significant positive associations were found between increased diarrhoea and high temperature at 4 weeks prior to the date of hospital visits (IRR = 1.07; 95 % CI = 1.04-1.08), high relative humidity (IRR = 1.13; 95 % CI = 1.12-1.15) and high (>90th percentile) cumulative rainfall (IRR = 1.05; 95 % CI = 1.05-1.08). The association between climate factors and diarrhoea was stronger in rural than urban areas. These findings in the context of the projected changes of climate conditions suggest that climate change will have important implications for residential health in Mekong Delta region.
Rowe, Clinton M; Loope, David B; Oglesby, Robert J; Van der Voo, Rob; Broadwater, Charles E
The supercontinent Pangea dominated our planet from the Permian into the Jurassic. Paleomagnetic reconstructions have been used to estimate the latitudinal position of Pangea during this 100-million-year period. Atmospheric circulation, recorded by eolian sandstones in the southwestern United States, shows a broad sweep of northeasterly winds over their northernmost extent, curving to become northwesterly in the south: This evidence is consistent with paleomagnetic reconstructions of the region straddling the equator in the Early Permian but is at odds with its northward movement to about 20 degrees N by the Early Jurassic. At least one of the following scenarios must be true: The latitude based on paleomagnetism is incorrect; the interpretation of how winds shaped the dunes is mistaken; the basic climate controls in the Jurassic were different from those of today; or the paleogeographic reconstructions available are insufficient to adequately reproduce the wind fields responsible for dune formation. PMID:18033879
Bribiesca Argomedo, Federico; Prieur, Christophe
Control of the Safety Factor Profile in a Tokamak uses Lyapunov techniques to address a challenging problem for which even the simplest physically relevant models are represented by nonlinear, time-dependent, partial differential equations (PDEs). This is because of the spatiotemporal dynamics of transport phenomena (magnetic flux, heat, densities, etc.) in the anisotropic plasma medium. Robustness considerations are ubiquitous in the analysis and control design since direct measurements on the magnetic flux are impossible (its estimation relies on virtual sensors) and large uncertainties remain in the coupling between the plasma particles and the radio-frequency waves (distributed inputs). The Brief begins with a presentation of the reference dynamical model and continues by developing a Lyapunov function for the discretized system (in a polytopic linear-parameter-varying formulation). The limitations of this finite-dimensional approach motivate new developments in the infinite-dimensional framework. The t...
Bjorsne, Anna-Karin; Rutting, Tobias; Ambus, Per
of exposure to three climate change factors, i.e. warming, elevated CO2 (eCO(2)) and summer drought, applied both in isolation and in combination. By conducting laboratory N-15 tracing experiments we show that warming increased both gross N mineralization and nitrification rates. In contrast, gross...... experiments for a better understanding of N cycling in a changing climate, which is a prerequisite for more reliable model predictions of ecosystems responses to climate change.......The ongoing climate change affects biogeochemical cycling in terrestrial ecosystems, but the magnitude and direction of this impact is yet unclear. To shed further light on the climate change impact, we investigated alterations in the soil nitrogen (N) cycling in a Danish heathland after 5 years...
Full Text Available This paper presents an analysis of a complexity of interrelated structural, petrologic and climatic factors that considerably affect the instabilities in the open cast mine of Gradna, near Samobor. The instabilities provoke the slope failures such as slides and slumps of rock material. During the protracted periodical investigations, the relationship among the factors of regional geology, tectonics, structural geology, petrography, engineering geology, rock mechanics and the rock mining technology was observed in the area. The local control of hydrogeologic properties, as well as climatic fluctuations of temperature and precipitation on the slope stability, was also recognized. It turned out that the structural relationships, characteristic of the manifold cataclased dolomite, stimulated the development of local instabilities, particularly during the period of low temperatures affecting the process of ground-water accumulation. When the temperatures are worm, the ground-water circulation is slow, exerting only the small-scale influence on the local instabilities (the paper is published in Croatian.
D’Andrea, William J.; Huang, Yongsong; Sherilyn C Fritz; Anderson, N. John
West Greenland has had multiple episodes of human colonization and cultural transitions over the past 4,500 y. However, the explanations for these large-scale human migrations are varied, including climatic factors, resistance to adaptation, economic marginalization, mercantile exploration, and hostile neighborhood interactions. Evaluating the potential role of climate change is complicated by the lack of quantitative paleoclimate reconstructions near settlement areas and by the relative stab...
A. I. J. M. van Dijk
Daily streamflow data were analysed to assess which climate and terrain factors best explain streamflow response in 183 Australian catchments. Assessed descriptors of catchment response included the parameters of fitted baseflow models, and baseflow index (BFI), average quick flow and average baseflow derived by baseflow separation. The variation in response between catchments was compared with indicators of catchment climate, morphology, geology, soils and land use. Spatial coherence in the ...
Eccles Martin P; Goh Teik T; Steen Nick
Abstract Background Quality of care in general practice may be affected by the team climate perceived by its health and non-health professionals. Better team working is thought to lead to higher effectiveness and quality of care. However, there is limited evidence available on what affects team functioning and its relationship with quality of care in general practice. This study aimed to explore individual and practice factors that were associated with team climate, and to explore the relatio...
Losleben, M. V.; Weltzin, J. F.; Billick, I.; Jones, D.
Phenology is the study of the timing of recurring biological phases, the causes of their timing with regard to biotic and abiotic forces, and the interrelation among phases of the same or different species. Although phenology is a far-reaching component of environmental science, it is poorly understood relative to other ecological patterns and processes. For example, it is unclear how climatic attributes affect the phenology of different organisms, and how those attributes vary in importance on different spatial and temporal scales. We know phenology affects the abundance and diversity of organisms, and their function and interactions in the environment, especially their effects on fluxes in water, energy, and chemical elements at various scales. With sufficient observations and understanding, phenology can be used as a predictor for other processes and variables of importance at local to global scales, and phenology could drive a variety of ecological forecast models with both scientific and practical applications. Integration of spatially-extensive phenological data and models with both short and long-term climatic forecasts offer a powerful agent for human adaptation to ongoing and future climate change. To fully utilize the value of phenology, not only more observations at more locations are needed, but also linkages between climatic factors and phenology must be more firmly established through linked direct observations and remotely sensed (Landscape Phenology or LSP) measurements with climatic factors. Sites along elevational gradients over a range of latitudes provide this opportunity. Elevational gradients present the phenological observational efficiency of compressed ecosystem transitions, and through climatic matching of sites, latitudinal range presents opportunities to control for additional abiotic factors such as day length, seasonal variability, storm track, and atmospheric chemistry. These sites also provide excellent platforms to advance new, and
Le Dang, Hoa; Li, Elton; Nuberg, Ian; Bruwer, Johan
Many countries are confronting climate change that threatens agricultural production and farmers' lives. Farmers' perceived risks of climate change and factors influencing those perceived risks are critical to their adaptive behavior and well-planned adaptation strategies. However, there is limited understanding of these issues. In this paper, we attempt to quantitatively measure farmers' perceived risks of climate change and explore the influences of risk experience, information, belief in climate change, and trust in public adaptation to those perceived risks. Data are from structured interviews with 598 farmers in the Mekong Delta. The study shows that perceived risks to production, physical health, and income dimensions receive greater priority while farmers pay less attention to risks to happiness and social relationships. Experiences of the events that can be attributed to climate change increase farmers' perceived risks. Information variables can increase or decrease perceived risks, depending on the sources of information. Farmers who believe that climate change is actually happening and influencing their family's lives, perceive higher risks in most dimensions. Farmers who think that climate change is not their concern but the government's, perceive lower risks to physical health, finance, and production. As to trust in public adaptation, farmers who believe that public adaptive measures are well co-ordinated, perceive lower risks to production and psychology. Interestingly, those who believe that the disaster warning system is working well, perceive higher risks to finance, production, and social relationships. Further attention is suggested for the quality, timing, and channels of information about climate change and adaptation.
Pawlowski, Andrzej; Guzman, Jose Luis; Rodríguez, Francisco; Berenguel, Manuel; Sánchez, José; Dormido, Sebastián
Monitoring and control of the greenhouse environment play a decisive role in greenhouse production processes. Assurance of optimal climate conditions has a direct influence on crop growth performance, but it usually increases the required equipment cost. Traditionally, greenhouse installations have required a great effort to connect and distribute all the sensors and data acquisition systems. These installations need many data and power wires to be distributed along the greenhouses, making the system complex and expensive. For this reason, and others such as unavailability of distributed actuators, only individual sensors are usually located in a fixed point that is selected as representative of the overall greenhouse dynamics. On the other hand, the actuation system in greenhouses is usually composed by mechanical devices controlled by relays, being desirable to reduce the number of commutations of the control signals from security and economical point of views. Therefore, and in order to face these drawbacks, this paper describes how the greenhouse climate control can be represented as an event-based system in combination with wireless sensor networks, where low-frequency dynamics variables have to be controlled and control actions are mainly calculated against events produced by external disturbances. The proposed control system allows saving costs related with wear minimization and prolonging the actuator life, but keeping promising performance results. Analysis and conclusions are given by means of simulation results. PMID:22389597
Berková, Hana; Zukal, Jan
Roč. 280, č. 4 (2010), s. 387-395. ISSN 0952-8369 R&D Projects: GA ČR GA206/01/1555; GA MŠk LC06073 Institutional research plan: CEZ:AV0Z60930519 Keywords : automatic registration * bats * flight activity * hibernaculum * seasonal changes Subject RIV: EG - Zoology Impact factor: 1.787, year: 2010
Full Text Available BACKGROUND: Antibiotic consumption in human populations is one of the factors responsible for the emergence of resistant organisms. It is important to track population-based data on an ongoing basis, and to explore the determinants of regional variation in antibiotic consumption.
Full Text Available Differences between glacial and pre-industrial potential vegetation patterns can conceptually be attributed to two factors: firstly to differences in the climate, caused by a strong increase in ice masses and the radiative effect of lower greenhouse gas concentrations, and secondly to differences in the ecophysiological effect of lower glacial atmospheric CO2 concentrations. The synergy emerging from these effects when operating simultaneously can be interpreted as sensitivity of the effect of enhancing physiologically available CO2 on shifting vegetation to climate warming. Alternatively and equally valid, it can be viewed as sensitivity of climatically induced vegetation changes to differences in physiologically available CO2. A first complete factor separation based on simulations with the MPI Earth System Model indicates that the pure climate effect mainly leads to a contraction or a shift in vegetation patterns when comparing glacial with pre-industrial simulation vegetation patterns. Globally, a reduction in fractional coverage of most plant functional types is seen – except for raingreen shrubs which strongly benefit from the colder and drier climate. The ecophysiological effect of CO2 appears to be stronger than the pure climate contribution for many plant functional types – in line with previous simulations. The ecophysiological effect of lower CO2 mainly yields a reduction in fractional coverage, a thinning of vegetation and a strong reduction in net primary production. The synergy appears to be as strong as each of the pure contributions locally. For tropical evergreen trees, the synergy appears strong also on global average. Hence this modelling study suggests that for tropical forests, an increase in CO2 has, on average, a stronger ecophysiological effect in warmer climate than in glacial climate. Alternatively, areal differences in tropical forests induced by climate warming can, on average, be expected to be larger with
Liu, Chunjiang; Berg, Bjørn; Kutsch, Werner;
The aim of this study is to determine the patterns of nitrogen (N) concentrations in leaf litter of forest trees as functions of climatic factors, annual average temperature (Temp, °C) and annual precipitation (Precip, dm) and of forest type (coniferous vs. broadleaf, deciduous vs. evergreen, Pin...... context of global warming, these regression equations are useful for a better understanding and modelling of the effects of geographical and climatic factors on leaf litter N at a regional and continental scale.......The aim of this study is to determine the patterns of nitrogen (N) concentrations in leaf litter of forest trees as functions of climatic factors, annual average temperature (Temp, °C) and annual precipitation (Precip, dm) and of forest type (coniferous vs. broadleaf, deciduous vs. evergreen, Pinus...
Full Text Available Influenza is one of the most important leading causes of respiratory illness in the countries located in the tropical areas of South East Asia and Thailand. In this study the climate factors associated with influenza incidence in Chiang Mai Province, Northern Thailand, were investigated. Identification of factors responsible for influenza outbreaks and the mapping of potential risk areas in Chiang Mai are long overdue. This work examines the association between yearly climate patterns between 2001 and 2008 and influenza outbreaks in the Chiang Mai Province. The climatic factors included the amount of rainfall, percent of rainy days, relative humidity, maximum, minimum temperatures and temperature difference. The study develops a statistical analysis to quantitatively assess the relationship between climate and influenza outbreaks and then evaluate its suitability for predicting influenza outbreaks. A multiple linear regression technique was used to fit the statistical model. The Inverse Distance Weighted (IDW interpolation and Geographic Information System (GIS techniques were used in mapping the spatial diffusion of influenza risk zones. The results show that there is a significance correlation between influenza outbreaks and climate factors for the majority of the studied area. A statistical analysis was conducted to assess the validity of the model comparing model outputs and actual outbreaks.
Qingzhu Gao; Wenquan Zhu; Schwartz, Mark W.; Hasbagan Ganjurjav; Yunfan Wan; Xiaobo Qin; Xin Ma; Williamson, Matthew A.; Yue Li
Detection and identification of the impacts of climate change on ecosystems have been core issues in climate change research in recent years. In this study, we compared average annual values of the normalized difference vegetation index (NDVI) with theoretical net primary productivity (NPP) values based on temperature and precipitation to determine the effect of historic climate change on global grassland productivity from 1982 to 2011. Comparison of trends in actual productivity (NDVI) with ...
XIAO, Liangjun; Ma, Ting; NING, Delu
Using the data of 11 climatic factors on 40 counties in the main producing areas of walnut of Yunnan Province, we analyze the impact of various climatic factors on the distribution of Yunnan walnut. The results show that Yunnan walnut has a great expectation on temperature and moisture. Temperature, including average temperature in January, average temperature in July, the average annual temperature and accumulated temperatureâ‰¥10 â„ƒ, has the greatest impact on the distribution of Yunnan wa...
McDowell, W.G.; Benson, A.J.; Byers, J.E.
1. Two dominant drivers of species distributions are climate and habitat, both of which are changing rapidly. Understanding the relative importance of variables that can control distributions is critical, especially for invasive species that may spread rapidly and have strong effects on ecosystems. 2. Here, we examine the relative importance of climate and habitat variables in controlling the distribution of the widespread invasive freshwater clam Corbicula fluminea, and we model its future distribution under a suite of climate scenarios using logistic regression and maximum entropy modelling (MaxEnt). 3. Logistic regression identified climate variables as more important than habitat variables in controlling Corbicula distribution. MaxEnt modelling predicted Corbicula's range expansion westward and northward to occupy half of the contiguous United States. By 2080, Corbicula's potential range will expand 25–32%, with more than half of the continental United States being climatically suitable. 4. Our combination of multiple approaches has revealed the importance of climate over habitat in controlling Corbicula's distribution and validates the climate-only MaxEnt model, which can readily examine the consequences of future climate projections. 5. Given the strong influence of climate variables on Corbicula's distribution, as well as Corbicula's ability to disperse quickly and over long distances, Corbicula is poised to expand into New England and the northern Midwest of the United States. Thus, the direct effects of climate change will probably be compounded by the addition of Corbicula and its own influences on ecosystem function.
Full Text Available China has the highest global incidence of hemorrhagic fever with renal syndrome (HFRS, constituting 90% of the cases in the world. Chongqing, located in the Three Gorges Reservoir Region, has been experiencing differences in the occurrence of HFRS from 1997 to 2008. The current study was designed to explore the effects of climate and rodent factors on the transmission of HFRS in Chongqing. Data on monthly HFRS cases, rodent strains, and climatic factors were collected from 1997 to 2008. Spatio-temporal analysis indicated that most HFRS cases were clustered in central Chongqing and that the incidence of HFRS decreased from 1997 to 2008. Poisson regression models showed that temperature (with lagged months of 0 and 5 and rainfall (with 2 lagged months were key climatic factors contributing to the transmission of HFRS. A zero-inflated negative binomial model revealed that rodent density was also significantly associated with the occurrence of HFRS in the Changshou district. The monthly trend in HFRS incidence was positively associated with rodent density and rainfall and negatively associated with temperature. Possible mechanisms are proposed through which construction of the dam influenced the incidence of HFRS in Chongqing. The findings of this study may contribute to the development of early warning systems for the control and prevention of HFRS in the Three Gorges Reservoir Region.
Fedorov, Alexey [Yale University
The central goal of this research project is to understand the properties of the ocean meridional overturning circulation (MOC) – a topic critical for understanding climate variability and stability on a variety of timescales (from decadal to centennial and longer). Specifically, we have explored various factors that control the MOC stability and decadal variability in the Atlantic and the ocean thermal structure in general, including the possibility abrupt climate change. We have also continued efforts on improving the performance of coupled ocean-atmosphere GCMs.
McMillen, Robert C PhD; Frese, Wolfgang; Cosby, Arthur G.
The Social Climate Survey provides a method to monitor changes in social and environmental objectives, as well as an institutional framework to organize and interpret these results. This approach operationalizes the concept of social climate into a set of quantifiable social and environmental indicators - organized within an institutional framework. Social scientists typically conceptualize societal changes as oc...
Rogers, R. D.; Salas, M.; Colon, A.
The northeastern Caribbean island of Puerto Rico is an exhumed Cenozoic island arc situated between the inactive Muertos trench to the south and the highly oblique Puerto Rican Trench to the north that forms the left- lateral strike-slip plate margin with North America. The rectangular island's long axis of 175 km parallels the east trending strike of the trenches with a near constant width of between 50 and 60 km. Puerto Rico receives the NE trade winds and has a tropical monsoonal climate. Puerto Rico has a distinct midline asymmetry with north draining watershed about twice the length and five times as large as south draining watershed. This midline asymmetry is more pronounced along the islands eastern third than the central or western thirds. River outlet spacing, mountain front sinuosity, and comparative hypsometry display similar east to west variability consistent with greater denudation in the eastern parts of the island. The southwestern fifth of the island is underlain by serpentinized ocean crust that forms the large diapiric Monte del Estado uplift. Active diapirism is indicated by highly asymmetric watersheds of the surrounding rivers and tributaries. Stream length gradient index calculated from 1:20,000 scale map data and compared to fault locations show little correlation suggesting that active faults does not significantly control Puerto Rico's landscape. Quantified morphologic data from the eastern two-thirds of Puerto Rico are consistent with a landscape developed in response to the precipitation derived from NE trade winds while serpentinite diapirism dominates the western third of the island. Individual active faults of Puerto Rico do not control the landscape development.
Fisher, T. R.; Sutton, A. J.; Gustafson, A. B.; Koskelo, A. I.; Fox, R. J.; Stone, J.
Water and elemental discharge from catchments is largely controlled by climate, soils, and land cover. Seasonal temperature and rainfall patterns determine the water available for stream discharge, and average annual air temperature is inversely correlated with the proportion of rainfall that is annually discharged as stream flow. At higher temperatures, an increasing fraction of the soil water is evapotranspired to the atmosphere as water vapor rather than discharged as stream flow. Hydrologic soil drainage properties determine whether precipitation is primarily directed horizontally as overland flow or vertically as infiltration to groundwater for baseflow. Concentrations of N in groundwater, primarily nitrate, reflect the surface land uses, particularly agriculture and residential areas with septic systems. However, hydric soils act as a trap for anthropogenic nitrate in groundwater, probably by denitrification in oxygen-poor, C-rich, micro-environments. Likewise, the P content of surface soils controls the P concentration in overland flow due to leaching of soluble P and erosion of particulate P. At the watershed scale, concentrations of N and P in stream discharge are augmented in proportion to the fraction of the basin in anthropogenic land uses such as agriculture and urban areas, which contribute nutrients via application of fertilizers and disposal of human waste. This anthropogenic fraction of a basin's land uses represents the human footprint upon the land which primarily determines the elevated N and P losses from the basin. N is relatively easily sampled because it is primarily transported as highly soluble nitrate in groundwater-supported baseflow; however, P sampling is more difficult because transport largely occurs episodically following storm events when both stream flow and P concentrations are high during brief periods. As a result, P concentrations and fluxes are almost certainly undersampled and underestimated compared to N fluxes, and fewer
Shiklomanov, Nikolay I.
). In their recent paper entitled 'An observational 71-year history of seasonally frozen ground changes in Eurasian high latitudes', Frauenfeld and Zhang (2011) provided detailed analysis of soil temperature data to assess 1930-2000 trends in seasonal freezing depth. The data were obtained from 387 Soviet non-permafrost meteorological stations. The authors performed systematic, quality-controlled, integrative analysis over the entire former Soviet Union domain. The long-term changes in depth of seasonal freezing were discussed in relation to such forcing variables as air temperature, degree days of freezing/thawing, snow depth and summer precipitation as well as modes of the North Atlantic Oscillation. The spatially average approach adopted for the study provides a generalized continental-scale trend. The study greatly improves, expands and extends previous 1956-90 analysis of the ground thermal regime over the Eurasian high latitudes (Frauenfeld et al 2004). Although the work of Frauenfeld and Zhang (2011) is the most comprehensive assessment of the continental-scale long-term trends in seasonal freezing available to date, more detailed analysis is needed to determine the effect of climate change on seasonally frozen ground. It should be noted that, in addition to the variables considered for analysis, other non-climatic factors affect the depth of freezing propagation. Unlike the surface, which is influenced by the climate directly, the ground even at shallow depth receives a climatic signal that is substantially modified by edaphic processes, contributing to highly localized thermal sensitivities of the ground to climatic forcing. Subsurface properties, soil moisture, and snow and vegetation covers influence the depth of freezing. Topography also plays an important role in establishing the ground thermal regime. It is an important determinant of the amount of heat received by the ground surface, affects the distribution of snow and vegetation, and influences the
ZHOU Tianjun; WU Bo; WEN Xinyu; LI Lijuan; WANG Bin
A fast version of the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geo- physical Fluid Dynamics (LASG)/Institute of Atmospheric Physics (IAP) climate system model is briefly documented. The fast coupled model employs a low resolution version of the atmospheric component Grid Atmospheric Model of IAP/LASG (GAMIL), with the other parts of the model, namely an oceanic com- ponent LASG/IAP Climate Ocean Model (LICOM), land component Common Land Model (CLM), and sea ice component from National Center for Atmospheric Research Community Climate System Model (NCAR CCSM2), as the same as in the standard version of LASG/IAP Flexible Global Ocean Atmosphere Land System model (FGOALS_g). The parameterizatious of physical and dynamical processes of the at- mospheric component in the fast version are identical to the standard version, although some parameter values are different. However, by virtue of reduced horizontal resolution and increased time-step of the most time-consuming atmospheric component, it runs faster by a factor of 3 and can serve as a useful tool for long- term and large-ensemble integrations. A 1000-year control simulation of the present-day climate has been completed without flux adjustments. The final 600 years of this simulation has virtually no trends in global mean sea surface temperatures and is recommended for internal variability studies. Several aspects of the control simulation's mean climate and variability axe evaluated against the observational or reanalysis data. The strengths and weaknesses of the control simulation are evaluated. The mean atmospheric circulation is well simulated, except in high latitudes. The Asian-Australian monsoonal meridional cell shows realistic features, however, an artificial rainfall center is located to the eastern periphery of the Tibetan Plateau persists throughout the year. The mean bias of SST resembles that of the standard version, appearing as a "double ITCZ" (Inter
Jones, P. D.; Harpham, C.; C. M. Goodess; Kilsby, C. G.
The purpose of this paper is to provide a method for perturbing Weather Generators (WGs) for future decades and to assess its effectiveness. Here the procedure is applied to the WG implemented within the UKCP09 package and assessed using data from a Regional Climate Model (RCM) simulation which provides a significant "climate change" between a control run period and a distant future. The WG is normally calibrated on observed data. For this study, data from an RCM control period (1961–1990) wa...
Liangjun; XIAO; Ting; MA; Delu; Ning
Using the data of 11 climatic factors on 40 counties in the main producing areas of walnut of Yunnan Province,we analyze the impact of various climatic factors on the distribution of Yunnan walnut.The results show that Yunnan walnut has a great expectation on temperature and moisture.Temperature,including average temperature in January,average temperature in July,the average annual temperature and accumulated temperature≥10℃,has the greatest impact on the distribution of Yunnan walnut,and is the primary dominant factor;moisture,including annual rainfall and average relative humidity,has a great impact on the distribution of Yunnan walnut,and is the secondary dominant factor.
Zhang, Jian; Nielsen, Scott; Mao, Lingfeng;
on Light Detection and Ranging-derived maximum forest canopy height (Hmax) to test hypotheses relating Hmax to current climate (water availability, ambient energy and water–energy dynamics), regional evolutionary and biogeographic history, historical climate change, and human disturbance. We derived...... relative importance of the different hypothesized factors. Hmax was inversely related to latitude (i.e. tall canopies at the equator), but with high geographical variability. Actual evapotranspiration and annual precipitation were the factors most correlated to Hmax globally, thus supporting the water–energy...... dynamics hypothesis. However, water limitation emerged as a key factor in tropical and temperate biomes within specific geographic regions, while energy limitation was a more important factor in boreal regions where temperature is more limiting to trees than water. Hmax exhibited strong variation among...
Marek, Michal V.; Janouš, Dalibor; Taufarová, Klára; Havránková, Kateřina; Pavelka, Marian; Kaplan, Věroslav; Marková, I.
Roč. 159, č. 5 (2011), s. 1035-1039. ISSN 0269-7491 R&D Projects: GA MŽP(CZ) SP/1A6/108/07; GA MŠk 2B06068 Institutional research plan: CEZ:AV0Z60870520 Keywords : carbon fluxes * net ecosystem exchange * spruce forest * beech forest * Grassland * agroecosystem * wetland * climate factors Subject RIV: EH - Ecology, Behaviour Impact factor: 3.746, year: 2011
Oluwakemi Adeola Obayelu
Full Text Available Climate change poses a great threat to human security through erratic rainfall patterns and decreasing crop yields, contributing to increased hunger. The perceptions of the indigenous people about climate change and their responses to climate change have significant roles to play in addressing climate change. Therefore a critical study on farmers’ choices of adaptation to is critical for ensuring food security poverty alleviation. A multi-stage random sampling technique was used to select 156 households in Ekiti state while descriptive statistics and multinomial logit were used to analyze the data obtained from the households. The results showed that the most widely used adaptation method by the farmers were soil and water conservation measures (67 percent. The multinomial logit analysis revealed that the factors explaining farmer’s choices of climate change adaptation include age of the farmers, gender of the household head, years of education, years of farming experience, household size, farmers information on climate change, farmers access to credit, farm income, non-farm income, livestock ownership and extension contact.
Petersen, Mark A.; Schaft, Arjan J. van der
This paper considers nonsquare spectral factorization of nonlinear input affine state space systems in continuous time. More specifically, we obtain a parametrization of nonsquare spectral factors in terms of invariant Lagrangian submanifolds and associated solutions of Hamilton–Jacobi inequalities.
Yi, Chuixiang; Ricciuto, Daniel; Li, Runze;
Understanding the relationships between climate and carbon exchange by terrestrial ecosystems is critical to predict future levels of atmospheric carbon dioxide because of the potential accelerating effects of positive climate–carbon cycle feedbacks. However, directly observed relationships betwe...
Full Text Available Understanding the factors underlying the spatio-temporal distribution of infectious diseases provides useful information regarding their prevention and control. Dengue fever spatio-temporal patterns result from complex interactions between the virus, the host, and the vector. These interactions can be influenced by environmental conditions. Our objectives were to analyse dengue fever spatial distribution over New Caledonia during epidemic years, to identify some of the main underlying factors, and to predict the spatial evolution of dengue fever under changing climatic conditions, at the 2100 horizon.We used principal component analysis and support vector machines to analyse and model the influence of climate and socio-economic variables on the mean spatial distribution of 24,272 dengue cases reported from 1995 to 2012 in thirty-three communes of New Caledonia. We then modelled and estimated the future evolution of dengue incidence rates using a regional downscaling of future climate projections.The spatial distribution of dengue fever cases is highly heterogeneous. The variables most associated with this observed heterogeneity are the mean temperature, the mean number of people per premise, and the mean percentage of unemployed people, a variable highly correlated with people's way of life. Rainfall does not seem to play an important role in the spatial distribution of dengue cases during epidemics. By the end of the 21st century, if temperature increases by approximately 3 °C, mean incidence rates during epidemics could double.In New Caledonia, a subtropical insular environment, both temperature and socio-economic conditions are influencing the spatial spread of dengue fever. Extension of this study to other countries worldwide should improve the knowledge about climate influence on dengue burden and about the complex interplay between different factors. This study presents a methodology that can be used as a step by step guide to model
Full Text Available Abstract Background Since updated population registers do not exist in many countries it is often difficult to sample valid population controls from the study base to a case-control study. Use of patient controls is an alternative option if the exposure experience under study for these patients are interchangeable with the experience for population controls. Patient controls may even be preferable from population controls under certain conditions. In this study we examine if colon cancer patients can serve as surrogates for proper population controls in case-control studies of occupational risk factors. Methods The study was conducted from 1995 to 1997. Incident colon cancer controls (N = 428 aged 35–69 years with a histological verified diagnosis and population controls (N = 583 were selected. Altogether 254 (59% of the colon cancer controls and 320 (55% of the population controls were interviewed about occupational, medical and life style conditions. Results No statistical significant difference for educational level, medical history or smoking status was seen between the two control groups. There was evidence of a higher alcohol intake, less frequent work as a farmer and less exposure to pesticides among colon cancer controls. Conclusions Use of colon cancer controls may provide valid exposure estimates in studies of many occupational risk factors for cancer, but not for studies on exposure related to farming.
Metals frequently occur at contaminated sites, where their potential toxicity and persistence require risk assessments that consider possible long-term changes. Changes in climate are likely to affect the speciation, mobility, and risks associated with metals. This paper provides an example of how the climate effect can be inserted in a commonly used exposure model, and how the exposure then changes compared to present conditions. The comparison was made for cadmium (Cd) exposure to 4-year-old children at a highly contaminated iron and steel works site in southeastern Sweden. Both deterministic and probabilistic approaches (through probability bounds analysis, PBA) were used in the exposure assessment. Potential climate-sensitive variables were determined by a literature review. Although only six of the total 39 model variables were assumed to be sensitive to a change in climate (groundwater infiltration, hydraulic conductivity, soil moisture, soil:water distribution, and two bioconcentration factors), the total exposure was clearly affected. For example, by altering the climate-sensitive variables in the order of 15% to 20%, the deterministic estimate of exposure increased by 27%. Similarly, the PBA estimate of the reasonable maximum exposure (RME, defined as the upper bound of the 95th percentile) increased by almost 20%. This means that sites where the exposure in present conditions is determined to be slightly below guideline values may in the future exceed these guidelines, and risk management decisions could thus be affected. The PBA, however, showed that there is also a possibility of lower exposure levels, which means that the changes assumed for the climate-sensitive variables increase the total uncertainty in the probabilistic calculations. This highlights the importance of considering climate as a factor in the characterization of input data to exposure assessments at contaminated sites. The variable with the strongest influence on the result was the
P K Bhatia; ROOSEL JAIN; GULSHAN TANEJA,
In the present study, the probabilistic analysis of an automatic power factor controller (APFC) system working in industry/factory is investigated. The power factor correction of electrical loads and energy losses due to poor power factor are the problems common to all industrial companies. Therefore, the study of APFC unit is of greatimportance. Initially, the system is operative with controlled power factor. Then it may transit to state with power factor not controlled. On the failure of th...
Silva-Flores, Ramón; Pérez-Verdín, Gustavo; Wehenkel, Christian
Biological diversity can be defined as variability among living organisms from all sources, including terrestrial organisms, marine and other aquatic ecosystems, and the ecological complexes which they are part of. This includes diversity within species, between species, and of ecosystems. Numerous diversity indices combine richness and evenness in a single expression, and several climate-based explanations have been proposed to explain broad-scale diversity patterns. However, climate-based water-energy dynamics appears to be an essential factor that determines patterns of diversity. The Mexican Sierra Madre Occidental occupies an area of about 29 million hectares and is located between the Neotropical and Holarctic ecozones. It shelters a high diversity of flora, including 24 different species of Pinus (ca. 22% on the whole), 54 species of Quercus (ca. 9-14%), 7 species of Arbutus (ca. 50%) and many other trees species. The objectives of this study were to model how tree species diversity is related to climatic and geographic factors and stand density and to test the Metabolic Theory, Productivity-Diversity Hypothesis, Physiological Tolerance Hypothesis, Mid-Domain Effect, and the Water-Energy Dynamic Theory on the Sierra Madre Occidental, Durango. The results supported the Productivity-Diversity Hypothesis, Physiological Tolerance Hypothesis and Water-Energy Dynamic Theory, but not the Mid-Domain Effect or Metabolic Theory. The annual aridity index was the variable most closely related to the diversity indices analyzed. Contemporary climate was found to have moderate to strong effects on the minimum, median and maximum tree species diversity. Because water-energy dynamics provided a satisfactory explanation for the patterns of minimum, median and maximum diversity, an understanding of this factor is critical to future biodiversity research. Quantile regression of the data showed that the three diversity parameters of tree species are generally higher in cold
Full Text Available Climate factors including soil temperature and moisture, incident solar radiation, and atmospheric carbon dioxide concentration are important environmental controls on methane (CH4 emissions from northern wetlands. We investigated the spatio-temporal distributions of the influence of these factors on northern high latitude wetland CH4 emissions using an enhanced version of the Variable Infiltration Capacity (VIC land surface model. We simulated CH4 emissions from wetlands across the pan-Arctic domain over the period 1948–2006, yielding annual average emissions of 35.1 ± 6.7 Tg CH4 yr−1 for the period 1997–2006. We characterized historical sensitivities to air temperature, precipitation, incident long- and short-wave radiation, and atmospheric [CO2] as a function of average summer air temperature and precipitation. Emissions from relatively warm and dry wetlands in the southern (permafrost-free portion of the domain were positively correlated with precipitation and negatively correlated with air temperature, while emissions from wetter and colder wetlands further north (permafrost were positively correlated with air temperature. Over the entire period 1948–2006, our reconstructed CH4 emissions increased by 20%, over 90% of which can be attributed to climate change. An increasing trend in summer air temperature explained the majority of the climate-related variance. We estimated future emissions in response to 21st century warming as predicted by CMIP5 model projections to result in end of century CH4 emissions 42% higher than our reconstructed 1997–2006 emissions, accompanied by the northward migration of warmer- and drier-than optimal conditions for CH4 emissions, implying a reduced role for temperature in driving future increases in emissions.
Köse, Gaye; Temiz, Ali; Akbaş, Selçuk; Özkan, Emre
In this study, 2×100×200 mm wood veneers obtained from Scots pine (Pinus sylvestris L.), European black pine (Pinus nigra Arn.) and beech (Fagus orientalis L.) wood were exposed to outdoor climate conditions at three different cities (Trabzon, Artvin, and Kastamonu) of Black Sea region in Turkey for totally 4 months from May to August, 2012. The aim of this study was to investigate the effect of climate factors on the changes occurred on different types of wood veneers that were subjected to ...
During the Neoproterozoic glaciations tropical continents were covered by active glaciers that extended down to sea level. To explain these glaciers, the Snowball Earth hypothesis assumes that oceans were completely sea-ice covered during these glaciation, but there is an ongoing debate whether or not some regions of the tropical oceans remained open. In this talk, I will describe past and ongoing climate modelling activities with the comprehensive coupled climate model ECHAM5/MPI-OM that identify and compare factors that control the initiation of Snowball Earth events. I first show that shifting the continents from their present-day location to their Marinoan (635 My BP) low-latitude location increases the planetary albedo, cools the climate, and thereby allows Snowball Earth initiation at higher levels of total solar irradiance and atmospheric CO2. I then present simulations with successively lowered bare sea-ice albedo, disabled sea-ice dynamics, and switched-off ocean heat transport. These simulations show that both lowering the bare sea-ice albedo and disabling sea-ice dynamics increase the critical sea-ice cover in ECHAM5/MPI-OM, but sea-ice dynamics due to strong equatorward sea-ice transport have a much larger influence on the critical CO2. Disabling sea-ice transport allows a state with sea-ice margin at 10 deg latitude by virtue of the Jormungand mechanism. The accumulation of snow on land, in combination with tropical land temperatures below or close to freezing, suggests that tropical land glaciers could easily form in such a state. However, in contrast to aquaplanet simulations without ocean heat transport, there is no sign of a Jormungand hysteresis in the coupled simulations. Ocean heat transport is not responsible for the lack of a Jormungand hysteresis in the coupled simulations. By relating the above findings to previous studies, I will outline promising future avenues of research on the initiation of Snowball Earth events. In particular, an
Schwabedissen, S. G.; Reed, S.; Lohse, K. A.; Magnuson, T. S.
Nitrogen, next to water, is believed to be the main limiting resource in arid and semi-arid ecosystems. Biological soil crusts (biocrusts) -a surface community of mosses, lichens and cyanobacteria-have been found to be the main influx of "new" nitrogen (N) into many dryland ecosystems. Controls on biocrust N fixation rates include climate (temperature and moisture), phosphorus availability, and disturbance factors such as trampling, yet a systematic examination of climatic and disturbance controls on biocrusts communities is lacking. Biocrust samples were collected along an elevation gradient in the Reynolds Creek Experimental Watershed near Murphy, Idaho. Four sites were selected from a sagebrush steppe ecosystem with precipitation ranging from ≤250mm/yr to ≥1100mm/yr. Each site included 5 grazed plots and one historic exclosure plot that has been free from grazing for more than 40 years. Five samples each were collected from under plants and from interplant spaces from the grazed plots and exclosures and analyzed for potential N fixation using an acetylene reduction assay. We hypothesized that N fixation rates would be the highest in the exclosures of the two middle sites along the elevation gradient, due to the lack of disturbance and optimal temperature and moisture, respectively. As predicted, results showed higher rates of potential N fixation in exclosures than non-exclosures at a mid-elevation 8.4 ± 3.1 kg N/ha/yr in the exclosures compared to 1.8 ± 1.5 kg N/ha/yr indicating that grazing may reduce N fixation activity. Interestingly, rates were 2-5 times lower under plant canopies compared to interplant spaces at all but the highest elevation site. Findings from our study suggest that biocrust N fixation may be a dominant input of N into theses dryland systems and, in line with our hypotheses, that climate, location within the landscape, and disturbance may interact to regulate the rates of this fundamental ecosystem process.
Zorza, Juan P.; Marino, Julián; Mesas, Alberto Acosta
The purpose of this study was to determine the predictive power of effortful control (EC) and empathy for perception of school climate. Self-report measures of EC, dispositional empathy, and perception of school climate were obtained for 398 students (204 females) aged 12 to 13. Sociometric status was peer-evaluated, and academic achievement was…
Leibbrand, Hans; Stenke, Iris-Marina [Thales Rail Signalling Solutions GmbH, Stuttgart (Germany)
Energy is expensive, and the emissions of gases affecting the climate, resulting from the consumption of fuels and electricity, are not of a negligible amount. The modern command, control and signalling systems that are used by railways are thus also capable of making their contribution to protecting the environment and the climate. (orig.)
Prinz, Rainer; Nicholson, Lindsey; Gurgiser, Wolfgang; Mölg, Thomas; Kaser, Georg
Glaciers in the tropics can provide information about regional climate, its dynamics, and its evolution over decadal and centennial time scales, if their interaction with the atmosphere is understood, and their changes are documented or reconstructed. The glaciers on Mount Kenya capture a climate signal from the mid troposphere at about 5 km a.s.l., where our knowledge of climate change is scarce and controversial. We use in-situ meteorological and glaciological observations to optimize and validate a physically-based, process-orientated energy and mass balance model to quantify the exchange processes between the glacier surface and the atmosphere above and to explore the sensitivity of energy and mass exchanges to changing climatic conditions. Currently the glacier loses mass due to the imbalance between insufficient accumulation and enhanced melt, because radiative energy gains cannot be compensated by turbulent energy sinks. Exchanging model input data with synthetic climate scenarios, which were sampled from the meteorological measurements and account for coupled climatic variable perturbations, reveal that the current mass balance is most sensitive to changes in atmospheric moisture (via its impact on solid precipitation, cloudiness and surface albedo). Scenarios with lower air temperatures are drier and associated with lower accumulation and increased net radiation due to reduced cloudiness and albedo. Hence, similar to the glaciers of nearby Kilimanjaro, the recession of Lewis Glacier is not because of increased air temperatures, but because of decreased atmospheric moisture. If the climate scenarios currently producing positive mass balances are applied to Lewis Glacier's late 19th century maximum extent (L19), negative mass balances are the result, meaning that the conditions required sustaining the glacier in its L19 extent are not reflected in today's climate observations. Alternatively, a balanced mass budget for the L19 extent can be explained by
Jain, M.; Mondal, P.; Galford, G. L.; DeFries, R. S.
India is predicted to be one of the most vulnerable regions in terms of agricultural sensitivity to future climate changes. Approximately 69% of India's population is rural, and over 55% of the working population relies on agriculture for sustenance and livelihoods. Indian smallholder farmers who own less than 2 ha of farmland represent 78% of the total Indian farmers and produce 41% of the country's food crops. These smallholder farmers are among some of the most vulnerable communities to climatic and economic changes due to limited access to technology, infrastructure, markets, and institutional or financial support in the case of adverse climatic events. Baseline information on agricultural sensitivity to climate variability will provide useful information for regional-level, and eventually state- and national-level, strategies and policies that promote adaption to climate variability. We use a decade of remote sensing analysis of cropping patterns and climatic factors along with census data for irrigation and demographic factors to understand winter cropping trajectories across agro-ecological zones in India. Findings from multiple agro-ecological zones indicate that there are three primary trajectories in winter cropping in India - increasing, fluctuating, and decreasing. In the Central Indian Highlands, for example, the most dominant trend is that of fluctuating cropped area, ranging between ~37,300 km2 in 2010 and ~21,100 km2 in 2013, which is associated with village-level access to irrigation and local labor dynamics. Clay soil type and increasing irrigation coverage were associated with intensification. Yet, suitable soil type and access to irrigation do not reduce vulnerability to high daytime temperatures that is negatively associated with winter crop cover. With pronounced winter warming projected in the coming decades, effective adaptation by smallholder farmers would require additional strategies, such as access to fine-scale temperature forecasts
A. I. J. M. van Dijk
Full Text Available Daily streamflow data were analysed to assess which climate and terrain factors best explain streamflow response in 183 Australian catchments. Assessed descriptors of catchment response included the parameters of fitted baseflow models, and baseflow index (BFI, average quick flow and average baseflow derived by baseflow separation. The variation in response between catchments was compared with indicators of catchment climate, morphology, geology, soils and land use. Spatial coherence in the residual unexplained variation was investigated using semi-variogram techniques. A linear reservoir model (one parameter; recession coefficient produced baseflow estimates as good as those obtained using a non-linear reservoir (two parameters and for practical purposes was therefore considered an appropriate balance between simplicity and explanatory performance. About a third (27–34% of the spatial variation in recession coefficients and BFI was explained by catchment climate indicators, with another 53% of variation being spatially correlated over distances of 100–150 km, probably indicative of substrate characteristics not captured by the available soil and geology data. The shortest recession half-times occurred in the driest catchments and were attributed to intermittent occurrence of fast-draining (possibly perched groundwater. Most (70–84% of the variation in average baseflow and quick flow was explained by rainfall and climate characteristics; another 20% of variation was spatially correlated over distances of 300–700 km, possibly reflecting a combination of terrain and climate factors. It is concluded that catchment streamflow response can be predicted quite well on the basis of catchment climate alone. The prediction of baseflow recession response should be improved further if relevant substrate properties were identified and measured.
A model predictive control (MPC) method has been efficiently applied to APR-type reactor as a control bank controller for reactor power level and axial power distribution controls. MPC algorithm is to solve the optimization problem to minimize objective function over a future horizon. Normally, input weighting factors in objective function should be optimized to enhance the performance of controller. In this paper, input weighting factor has been determined by design of experiment (DOE) method
Full Text Available Fire weather indices predict fire extent from meteorological conditions assuming a monotonic function; this approach is frequently used to predict future fire patterns under climate change scenarios using linear extrapolation. However, the relationship between weather and fire extent may potentially depend on the existence of fuel humidity thresholds above which this relationship changes dramatically, challenging this statistical approach. Here we combine the continuous and the threshold approaches to analyze satellite-detected fires in Europe during 2001–2010 in relation to meteorological conditions, showing that fire size response to increasing dryness follows a ramp function, i.e. with two plateaus separated by a phase of monotonic increase. This study confirms that at a continental and a high-resolution temporal scales, large fires are very unlikely to occur under moist conditions, but it also reveals that fire size stops to be controlled by fuel humidity above a given threshold of dryness. Thus, fuel humidity control only applies when fire is not limited by other factors such as fuel load, as large fires are virtually absent in dry regions with less than 500 mm of average annual rainfall, i.e. where fuel amount is insufficient. In regions with sufficient fuel, other factors such as fire suppression or fuel discontinuity can impede large fires even under very dry weather conditions. These findings are relevant under current climatic trends in which the fire season length, in terms of number of days with DC (drought code values above the observed thresholds (break points, is increasing in many parts of the Mediterranean, while it is decreasing in Eastern Europe and remains unchanged in Central Europe.
Optimizing control systems supplement conventional Distributed Control Systems and Programmable Logic Controllers. They continuously implement set points, which aim at maximizing the profitability of plant operation. They are becoming an integral part of modern mineral processing plants. This trend is justified by economic considerations, optimizing control being among the most cost-effective methods of improving metallurgical plant performance. The paper successively analyzes three sets of factors, which influence the profitability of optimizing control systems, and provides guidelines for analyzing the potential value of an optimizing control system at a given operation: external factors, such as economic factors and factors related to plant feed; features of the optimizing control system; and subsequent maintenance of the optimizing control system. It is shown that pay back times for optimization control projects are typically measured in days. The OCS software used by the authors for their applications is described briefly. (author)
Prinz, R.; Nicholson, L. I.; Mölg, T.; Gurgiser, W.; Kaser, G.
The Lewis Glacier on Mt. Kenya is one of the best studied tropical glaciers and has experienced considerable retreat since a maximum extent in the late 19th century (L19). From distributed mass and energy balance modelling, this study evaluates the current sensitivity of the surface mass and energy balance to climatic drivers, explores climate conditions under which the L19 maximum extent might have been sustained, and discusses the potential for using the glacier retreat to quantify climate change. Multi-year meteorological measurements at 4828 m provide data for input, optimization, and evaluation of a spatially distributed glacier mass balance model to quantify the exchanges of energy and mass at the glacier-atmosphere interface. Currently the glacier loses mass due to the imbalance between insufficient accumulation and enhanced melt, because radiative energy gains cannot be compensated by turbulent energy sinks. Exchanging model input data with synthetic climate scenarios, which were sampled from the meteorological measurements and account for coupled climatic variable perturbations, reveals that the current mass balance is most sensitive to changes in atmospheric moisture (via its impact on solid precipitation, cloudiness, and surface albedo). Positive mass balances result from scenarios with an increase of annual (seasonal) accumulation of 30 % (100 %), compared to values observed today, without significant changes in air temperature required. Scenarios with lower air temperatures are drier and associated with lower accumulation and increased net radiation due to reduced cloudiness and albedo. If the scenarios currently producing positive mass balances are applied to the L19 extent, negative mass balances are the result, meaning that the conditions required to sustain the glacier in its L19 extent are not reflected in today's meteorological observations using model parameters optimized for the present-day glacier. Alternatively, a balanced mass budget for the
Zapata-Rios, Xavier; McIntosh, Jennifer; Rademacher, Laura; Troch, Peter A.; Brooks, Paul D.; Rasmussen, Craig; Chorover, Jon
The critical zone (CZ) can be conceptualized as an open system reactor that is continually transforming energy and water fluxes into an internal structural organization and dissipative products. In this study, we test a controlling factor on water transit times (WTT) and mineral weathering called Effective Energy and Mass Transfer (EEMT). We hypothesize that EEMT, quantified based on local climatic variables, can effectively predict WTT within—and mineral weathering products from—the CZ. This study tests whether EEMT or static landscape characteristics are good predictors of WTT, aqueous phase solutes, and silicate weathering products. Our study site is located around Redondo Peak, a rhyolitic volcanic resurgent dome, in northern New Mexico. At Redondo Peak, springs drain slopes along an energy gradient created by differences in terrain aspect. This investigation uses major solute concentrations, the calculated mineral mass undergoing dissolution, and the age tracer tritium and relates them quantitatively to EEMT and landscape characteristics. We found significant correlations between EEMT, WTT, and mineral weathering products. Significant correlations were observed between dissolved weathering products (Na+ and DIC), 3H concentrations, and maximum EEMT. In contrast, landscape characteristics such as contributing area of spring, slope gradient, elevation, and flow path length were not as effective predictive variables of WTT, solute concentrations, and mineral weathering products. These results highlight the interrelationship between landscape, hydrological, and biogeochemical processes and suggest that basic climatic data embodied in EEMT can be used to scale hydrological and hydrochemical responses in other sites.
Md Mahmudul Haque
Full Text Available Ensuring adequate water supply to urban areas is a challenging task due to factors such as rapid urban growth, increasing water demand and climate change. In developing a sustainable water supply system, it is important to identify the dominant water demand factors for any given water supply scheme. This paper applies principal components analysis to identify the factors that dominate residential water demand using the Blue Mountains Water Supply System in Australia as a case study. The results show that the influence of community intervention factors (e.g. use of water efficient appliances and rainwater tanks on water demand are among the most significant. The result also confirmed that the community intervention programmes and water pricing policy together can play a noticeable role in reducing the overall water demand. On the other hand, the influence of rainfall on water demand is found to be very limited, while temperature shows some degree of correlation with water demand. The results of this study would help water authorities to plan for effective water demand management strategies and to develop a water demand forecasting model with appropriate climatic factors to achieve sustainable water resources management. The methodology developed in this paper can be adapted to other water supply systems to identify the influential factors in water demand modelling and to devise an effective demand management strategy.
Kuo-Jen Lin; Po-Hung Lin; Sheng-Hsien Chu; Hsiao-Wen Chen; Ta-Min Wang; Yang-Jen Chiang; Kuan-Lin Liu; Hsu-Han Wang
Background: Urolithiasis is a common disease with high prevalence and recurrence. Its incidence varies in different geographic locations, and there are evidences that meteorological factors also affect urinary stone formation. The aim of this study is to analyze the effects of climate parameters on the numbers of shockwave treatments for urinary stones in our hospital, in order to understand the effects of these parameters on the prevalence of urolithiasis in northern Taiwan. Methods: We r...
Assessing potential climate effects of natural gas versus coal electricity generation is complicated by the large number of factors reported in life cycle assessment studies, compounded by the large number of proposed climate metrics. Thus, there is a need to identify the key factors affecting the climate effects of natural gas versus coal electricity production, and to present these climate effects in as clear and transparent a way as possible. Here, we identify power plant efficiencies and methane leakage rates as the factors that explain most of the variance in greenhouse gas emissions by natural gas and coal power plants. Thus, we focus on the role of these factors in determining the relative merits of natural gas versus coal power plants. We develop a simple model estimating CO2 and CH4 emissions from natural gas and coal power plants, and resulting temperature change. Simple underlying physical changes can be obscured by abstract evaluation metrics, thus we focus our analysis on the time evolution of global mean temperature. We find that, during the period of plant operation, if there is substantial methane leakage, natural gas plants can produce greater near-term warming than coal plants with the same power output. However, if methane leakage rates are low and power plant efficiency is high, natural gas plants can produce some reduction in near-term warming. In the long term, natural gas power plants produce less warming than would occur with coal power plants. However, without carbon capture and storage natural gas power plants cannot achieve the deep reductions that would be required to avoid substantial contribution to additional global warming. (letter)
Bogle, Rian C.; Redsteer, Margaret Hiza; Vogel, John M.
Aeolian sand covers extensive areas of the Navajo Nation in the southwestern United States. Much of this sand is currently stabilized by vegetation, although many drier parts of these Native lands also have active and partly active dunes. Current prolonged drought conditions that started in the mid-1990s are producing significant changes in dune mobility. Reactivation of regional aeolian deposits due to drought or increasing aridity from rising temperatures resulting from climate change could have serious consequences for human and animal populations, agriculture, grazing, and infrastructure. To understand and document the current and future potential for mobility, seasonally repeated surveys were used to track the location of multiple active barchan dunes. By utilizing Real-Time Kinematic GPS field surveys and simultaneously collecting in-situ meteorological data, it is possible to examine climatic parameters and seasonal variations that affect dune mobility and their relative influences. Through analysis of the recorded data, we examined the fit of various climate parameters, and demonstrate that under the current prolonged drought, wind power is the dominant factor controlling dune mobility.
Full Text Available Haemorrhagic fever with renal syndrome (HFRS is a rodent-borne disease that poses a serious public health threat in China. HFRS is caused by hantaviruses, mainly Seoul virus in urban areas and Hantaan virus in agricultural areas. Although preventive measures including vaccination programs and rodent control measures have resulted in a decline in cases in recent years, there has been an increase in incidence in some areas and new endemic areas have emerged. This review summarises the recent literature relating to the effects of climatic factors on the incidence of HFRS in China and discusses future research directions. Temperature, precipitation and humidity affect crop yields, rodent breeding patterns and disease transmission, and these can be influenced by a changing climate. Detailed surveillance of infections caused by Hantaan and Seoul viruses and further research on the viral agents will aid in interpretation of spatiotemporal patterns and a better understanding of the environmental and ecological drivers of HFRS amid China's rapidly urbanising landscape and changing climate.
M. L. NEAGU
Full Text Available Wind is the main factor involved in changing the natural balance of forest ecosystems from Gurghiu hydrographic basin. Strong winds are responsible for windthrows, especially in spruce arboretums, the most representative of the wood species form the studied area. Trees can be partially (bending of trunks, branches and broken tops or totally (pulling the roots damaged. Windthrows occurrence is closely related to the climatic factors, physical-geographical conditions (slope, soil characteristics and arboretum characteristics (structure, age, consistency are also important. The imbalance induced by those phenomena is emphasized by pest invasions (especially Ips Typographus which are quite frequent after windthrows.Our study represents a detailed analysis of the way in which the structure and the balance of the forest ecosystems of Gurghiu basin undergo major changes, because the climatic factors (wind, snow action. Case study is the windthrow occurred on June 2010, when 200,000 m³ of wood was windthrowed, over a total area of 5,953 ha in P.U. II Isticeu (Fâncel Forest Range and partially in P.U. I Glăjărie (the same forest range. The methodology used includes the analysis of climatic data, statistical data processing, GIS techniques for mapping the areas vulnerable to windthrows, synthesis.
Emaziye, P. O., R. N. Okoh
Full Text Available The study focused on the critical analysis of climate change factors (temperature and rainfall and its projected future values in the state. The main objective was to determine the trends of climate change factors (temperature and rainfall. And the specific objective was to determine the projected future trends of climate change factors in the state. Multistage sampling procedure was used in the random selection of states, local government, communities and rural households for the research study. Annual mean time series data of temperature and rainfall were collected from Nigerian Meteorological Agency (NIMET. Data were also obtained from structure questionnaire survey. The collected data were analyzed using descriptive statistics, trend analysis and growth model. The study reveals that there were increasing trends of temperature values and decreasing rainfall values in the state. But their projected future values witnessed an increasing trend. The increasing trends in temperature values may lead to a situation were crops will be smothered by excessive heat thereby reducing food production in the state. The study therefore recommends that meteorological station units should be established in the rural farming households in the state where accessibility is extremely difficult. This will make available meteorological data (information to the reach of the poor rural farming household for the attainment of food production.
Rehana, S.; Mujumdar, P. P.
SummaryA modeling framework is presented in this paper, integrating hydrologic scenarios projected from a General Circulation Model (GCM) with a water quality simulation model to quantify the future expected risk. Statistical downscaling with a Canonical Correlation Analysis (CCA) is carried out to develop the future scenarios of hydro-climate variables starting with simulations provided by a GCM. A Multiple Logistic Regression (MLR) is used to quantify the risk of Low Water Quality (LWQ) corresponding to a threshold quality level, by considering the streamflow and water temperature as explanatory variables. An Imprecise Fuzzy Waste Load Allocation Model (IFWLAM) presented in an earlier study is then used to develop adaptive policies to address the projected water quality risks. Application of the proposed methodology is demonstrated with the case study of Tunga-Bhadra river in India. The results showed that the projected changes in the hydro-climate variables tend to diminish DO levels, thus increasing the future risk levels of LWQ.
Full Text Available The Lewis Glacier on Mt Kenya is one of the best studied tropical glaciers and has experienced considerable retreat since a maximum extent in the late 19th century (L19. From distributed mass and energy balance modelling, this study evaluates the current sensitivity of the surface mass and energy balance to climatic drivers, explores climate conditions under which the L19 maximum extent might have sustained, and discusses the potential for using the glacier retreat to quantify climate change. Multiyear meteorological measurements at 4828 m provide data for input, optimization and evaluation of a spatially distributed glacier mass balance model to quantify the exchanges of energy and mass at the glacier–atmosphere interface. Currently the glacier loses mass due to the imbalance between insufficient accumulation and enhanced melt, because radiative energy gains cannot be compensated by turbulent energy sinks. Exchanging model input data with synthetic climate scenarios, which were sampled from the meteorological measurements and account for coupled climatic variable perturbations, reveal that the current mass balance is most sensitive to changes in atmospheric moisture (via its impact on solid precipitation, cloudiness and surface albedo. Positive mass balances result from scenarios with an increase of annual (seasonal accumulation of 30 % (100 %, compared to values observed today, without significant changes in air temperature required. Scenarios with lower air temperatures are drier and associated with lower accumulation and increased net radiation due to reduced cloudiness and albedo. If the scenarios currently producing positive mass balances are applied to the L19 extent, negative mass balances are the result, meaning that the conditions required to sustain the glacier in its L19 extent are not reflected in today's observations. Alternatively, a balanced mass budget for the L19 extent can be explained by changing model parameters that imply
Nola, F. J.
Three-phase power-factor controller with soft start is based on earlier version that does not control starting transients. Additional components serve to turn off "run" command signal and substitute gradual startup command signal during preset startup interval. Improved controller reduces large current surge that usually accompanies starting. Controller applies power smoothly, without causing motor vibrations.
Yin, Yuanyuan; Tang, Qiuhong; Wang, Lixin; Liu, Xingcai
Identifying the areas at risk of ecosystem transformation and the main contributing factors to the risk is essential to assist ecological adaptation to climate change. We assessed the risk of ecosystem shifts in China using the projections of four global gridded vegetation models (GGVMs) and an aggregate metric. The results show that half of naturally vegetated land surface could be under moderate or severe risk at the end of the 21(st) century under the middle and high emission scenarios. The areas with high risk are the Tibetan Plateau region and an area extended northeastward from the Tibetan Plateau to northeast China. With the three major factors considered, the change in carbon stocks is the main contributing factor to the high risk of ecosystem shifts. The change in carbon fluxes is another important contributing factor under the high emission scenario. The change in water fluxes is a less dominant factor except for the Tibetan Plateau region under the high emission scenario. Although there is considerable uncertainty in the risk assessment, the geographic patterns of the risk are generally consistent across different scenarios. The results could help develop regional strategies for ecosystem conservation to cope with climate change. PMID:26867481
N. O. Anyoha; F. N. Nnadi; J. Chikaire; J. A. Echetama; C. O. Utazi; R. A. Ihenacho
The aim of the study was to determine the socioeconomic factors influencing climate change adaptation among crop farmers in Umuahia South Area of Abia State, Nigeria. The specific objectives of the study were to determine socioeconomic characteristics of crop farmers in the area, determine farmers level of awareness of climate change in the area, ascertain effects of climate change in crop production, identify adaptation strategies adopted by the farmers in the area and determine socioeconomi...
George, G.J.; Ramachandran, Rakesh; Arun, N.
This paper presents a boost converter configuration, control scheme and design of single phase power factor controller for permanent magnet brushless DC motor (PMBLDCM) drive. PMBLDC motors are the latest choice of researchers, due to the high efficiency, silent operation, compact size, high...... reliability, and low maintenance requirements. The proposed Power Factor Controller topology improves power quality by improving performance of PMBLDCM drive, such as reduction of AC main current harmonics, near unity power factor. PFC converter forces the drive to draw sinusoidal supply current in phase with...... supply voltage. It uses a boost converter to obtain unity power factor with improved performance. The system includes a speed controller for PMBLDC drive and a voltage controller for boost converter.. The voltage or speed controllers can be realized using proportional integral (PI) controller...
The performance of Ontario Hydro's CANDU-based nuclear power plants has been excellent to date. Human factors engineering has been very much a part of the CANDU reactor design and development process. From the beginning operations staff has worked closely with designers. During commissioning and operation faults and errors are recorded and reported to the designers. A central group also carries out long-term evaluations of experience gained in nuclear plants around the world. The increasing complexity of nuclear power plants may in the short term increase operator's expectations for pay and job conditions, and in the longer term limit the number of people who want the job. Human factors engineering should minimize the complexity of systems, their interrelationships, the operator's tasks, and the environment in which they perform. Keep it simple
The Human-System Interface Design Review Guideline (NUREG-0700, Revision 1) was developed by the US Nuclear Regulatory Commission (NRC) to provide human factors guidance as a basis for the review of advanced human-system interface technologies. The guidance consists of three components: design review procedures, human factors engineering guidelines, and a software application to provide design review support called the ''Design Review Guideline.'' Since it was published in June 1996, Rev. 1 to NUREG-0700 has been used successfully by NRC staff, contractors and nuclear industry organizations, as well as by interested organizations outside the nuclear industry. The NRC has committed to the periodic update and improvement of the guidance to ensure that it remains a state-of-the-art design evaluation tool in the face of emerging and rapidly changing technology. This paper addresses the current research to update of NUREG-0700 based on the substantial work that has taken place since the publication of Revision 1
Full Text Available Background: Urolithiasis is a common disease with high prevalence and recurrence. Its incidence varies in different geographic locations, and there are evidences that meteorological factors also affect urinary stone formation. The aim of this study is to analyze the effects of climate parameters on the numbers of shockwave treatments for urinary stones in our hospital, in order to understand the effects of these parameters on the prevalence of urolithiasis in northern Taiwan. Methods: We retrospectively reviewed the records of extracorporeal shockwave lithotripsy (ESWL performed in our hospital from December 2006 to November 2011. Repeated ESWL performed in the same patient within 1 month was excluded, and we only counted as one ESWL in our study. Climate data of the corresponding months were collected from Central Weather Bureau. The available monthly meteorological data included highest, lowest, and average temperatures, humidity, rainfall, total rain days, sunshine hours, average atmospheric pressure, and wind speed. Results: Monthly ESWL number was positively correlated to temperature (r = 0.696, sunshine hours (r = 0.515, and wind speed (r = 0.369, while it was negatively correlated to humidity (r = -0.441 and atmospheric pressure (r = -0.568. Average monthly temperature had the strongest correlation to ESWL number (r2 = 0.484. Monthly rainfall and rain days were not significantly correlated to ESWL number. To investigate the climate parameters together, we introduced these correlated factors into the multivariate linear regression model which demonstrated only temperature (ß = 1.438, 95% CI: 3.703-9.144, p < 0.001 and atmospheric pressure (ß = 0.803, 95% CI: 0.790-5.428, p = 0.010 to be independently related to monthly ESWL number. Conclusion: Temperature and atmospheric pressure are associated with monthly ESWL number. Ambient temperature is the most important climate factor affecting the prevalence of urolithiasis in northern Taiwan.
Ruane, Alex C.; Major, David C.; Yu, Winston H.; Alam, Mozaharul; Hussain, Sk. Ghulam; Khan, Abu Saleh; Hassan, Ahmadul; Al Hossain, Bhuiya Md. Tamim; Goldberg, Richard; Horton, Radley M.; Rosenzweig, Cynthia
Diverse vulnerabilities of Bangladesh's agricultural sector in 16 sub-regions are assessed using experiments designed to investigate climate impact factors in isolation and in combination. Climate information from a suite of global climate models (GCMs) is used to drive models assessing the agricultural impact of changes in temperature, precipitation, carbon dioxide concentrations, river floods, and sea level rise for the 2040-2069 period in comparison to a historical baseline. Using the multi-factor impacts analysis framework developed in Yu et al. (2010), this study provides new sub-regional vulnerability analyses and quantifies key uncertainties in climate and production. Rice (aman, boro, and aus seasons) and wheat production are simulated in each sub-region using the biophysical Crop Environment REsource Synthesis (CERES) models. These simulations are then combined with the MIKE BASIN hydrologic model for river floods in the Ganges-Brahmaputra-Meghna (GBM) Basins, and the MIKE21Two-Dimensional Estuary Model to determine coastal inundation under conditions of higher mean sea level. The impacts of each factor depend on GCM configurations, emissions pathways, sub-regions, and particular seasons and crops. Temperature increases generally reduce production across all scenarios. Precipitation changes can have either a positive or a negative impact, with a high degree of uncertainty across GCMs. Carbon dioxide impacts on crop production are positive and depend on the emissions pathway. Increasing river flood areas reduce production in affected sub-regions. Precipitation uncertainties from different GCMs and emissions scenarios are reduced when integrated across the large GBM Basins' hydrology. Agriculture in Southern Bangladesh is severely affected by sea level rise even when cyclonic surges are not fully considered, with impacts increasing under the higher emissions scenario.
Handoko, K.B.; Rijkom, JE Zwart-van; Visee, H.F.; Hermens, W.A.; Hekster, Y.A.; Egberts, T.C.G.
To optimize seizure control it is important to identify modifiable factors. We conducted a case-control study to explore to what extent drug treatment-related factors are associated with seizures. Eighty-six patients with epilepsy were evaluated: 45 cases (recently experienced a seizure) and 41 cont
Wang, Tiejun; Franz, Trenton E.; Zlotnik, Vitaly A.
To meet the challenge of estimating spatially varying groundwater recharge (GR), increasing attention has been given to the use of vadose zone models (VZMs). However, the application of this approach is usually constrained by the lack of field soil hydraulic characteristics (SHCs) required by VZMs. To tackle this issue, SHCs based on the van Genuchten or Brooks-Corey model are generally estimated by pedotransfer functions or taken from texture based class averages. With the increasing use of this method, it is important to elucidate the controls of SHCs on computing GR mostly due to the high nonlinearity of the models. In this study, it is hypothesized that the nonlinear controls of SHCs on computing GR would vary with climatic conditions. To test this hypothesis, a widely used VZM along with two SHCs datasets for sand and loamy sand is used to compute GR at four sites in the continental Unites States with a significant gradient of precipitation (P). The simulation results show that the distribution patterns of mean annual GR ratios (GR ‾ / P ‾ , where GR ‾ and P ‾ are mean annual GR and P, respectively) vary considerably across the sites, largely depending on soil texture and climatic conditions at each site. It is found that GR ‾ / P ‾ is mainly controlled by the shape factor n in the van Genuchten model and the nonlinear effect of n on GR ‾ / P ‾ varies with climatic conditions. Specifically, for both soil textures, the variability in GR ‾ / P ‾ is smallest at the Andrews Forest with the highest P ‾ (191.3 cm/year) and GR ‾ / P ‾ is least sensitive to n; whereas, the variability in GR ‾ / P ‾ at the Konza Prairie (P ‾ = 84.2 cm/year) is the largest and GR ‾ / P ‾ is most sensitive to n. With further decreasing P ‾ , the nonlinear effect of n weakens at the Barta Brothers (P ‾ = 57.3 cm/year) and Sevilleta (P ‾ = 20.3 cm/year), leading to smaller GR ‾ / P ‾ variability at those two sites than at the Konza Prairie. The
Dunlop, S.; Hutchinson, D. J.
rockslide database comes with some constraints. Rockslides in the region have been recorded by Transportation Authorities. As a consequence, the data is only available along road or railway corridors. Rockslides that occur away from transportation infrastructure are not recorded and hence the dataset contains substantial spatial data discontinuity. There is also a temporal variance in the data. The county of Sogn og Fjordane has been recording rockslides semi-frequently since the 1970's, but there is a distinct increase in rockslide incidence in 1997, as recording procedures became more detailed and comprehensive. The county of Hordaland had very infrequent recording of rockslides prior to 2000, but since then has kept a very detailed rockslide inventory. Research completed thus far includes statistical analyses to establish relationships between the rockslides and their corresponding climate variables. Preliminary results indicate that short-term antecedent rainfall (less than 7 days before the event) and freeze-thaw cycles have the most important effect on the triggering of rockslides in the region. In fact, a high proportion of rockslides occur when these conditions occur simultaneously, when warm Atlantic storms make landfall during the cold winter months. These storms bring intense rainfall and raise temperatures above freezing levels, thus creating high runoff conditions. This ongoing research includes the study of historical storm events to gain a better understanding of the precise climatic conditions required to initiate rockslides. A primary goal of this research is to use geographic information system (GIS) technology to complete a rockslide hazard susceptibility map of the study area. A statistical approach is proposed, including many of the traditional factors (i.e. layers) used to generate hazard maps, such as: slope angle, slope curvature, geology, land use, etc. Factors related to climate will also be included as trends become apparent from the data analysis
Liu, J.; Chen, X. [North China Petroleum Administration, Zhengzhou (China). Xinxing Petroleum Company
Based on the study of pilot areas of Liulin and Anyang in North China, the coal reservoir permeability and the main geological controlling factors have been thoroughly researched. The results show that the development degree of cleats is the major controlling factor, followed by the effective stress, exokinetic fractures and the coal body structure. On the other hand, the cleat development is controlled by the coal rank and vitrinite content. 3 figs.
R. F. Wright
Full Text Available The RAIN and CLIMEX experiments at Risdalsheia, southernmost Norway, together cover 17 years (1984-2000 of whole-catchment manipulation of acid deposition and climate. A 1200 m2 roof placed over the forest canopy at KIM catchment excluded about 80% of ambient acid deposition; clean rain was sprinkled under the roof. A climate change treatment (3.7°C increase in air temperature and increase in air carbon dioxide concentrations to 560 ppmv was superimposed on the clean rain treatment for four years (1995-1998. Sea-salt inputs and temperature are climate-related factors that influence water chemistry and can confound long-term trends caused by changes in deposition of sulphur and nitrogen. The RAIN and CLIMEX experiments at Risdalsheia provided direct experimental data that allow quantitative assessment of these factors. Run-off chemistry responded rapidly to the decreased acid deposition. Sulphate concentrations decreased by 50% within three years; nitrate and ammonium concentrations decreased to new steady-state levels within the first year. Acid neutralising capacity increased and hydrogen ion and inorganic aluminium decreased. Similar recovery from acidification was also observed at the reference catchment, ROLF, in response to the general 50% reduction in sulphate deposition over southern Norway in the late 1980s and 1990s. Variations in sea-salt deposition caused large variations in run-off chemistry at the reference catchment ROLF and the year-to-year noise in acid neutralising capacity was as large as the overall trend over the period. These variations were absent at KIM catchment because the sea-salt inputs were held constant over the entire 17 years of the clean rain treatment. The climate change experiment at KIM catchment resulted in increased leaching of inorganic nitrogen, probably due to increased mineralisation and nitrification rates in the soils. Keywords: acid deposition, global change, water, soil, catchment, experiment, Norway.
Lu, Xinmin; Siemann, Evan; He, Minyan; Wei, Hui; Shao, Xu; Ding, Jianqing
Climate change may shift interactions of invasive plants, herbivorous insects and native plants, potentially affecting biological control efficacy and non-target effects on native species. Here, we show how climate warming affects impacts of a multivoltine introduced biocontrol beetle on the non-target native plant Alternanthera sessilis in China. In field surveys across a latitudinal gradient covering their full distributions, we found beetle damage on A. sessilis increased with rising tempe...
Whittaker, Alexander; Boulton, Sarah; Kent, Emiko; Alçiçek, Cihat
The plan-view and vertical rates at which transient knickpoints propagate through a landscape fundamentally controls geomorphic response times to tectonic and climatic perturbations. Here we present knickpoint retreat rates upstream of active faults for bedrock catchments in the Gediz graben of Turkey where past climate is well documented but where the history of faulting is not fully constrained. The rivers upstream of the normal fault-bounded graben each contain a non-lithologic knickpoint, including those that drain through inferred fault segment boundaries. Knickpoint heights measured vertically from the fault scale with footwall relief and documented fault throw (vertical displacement). Consequently, we deduce these knickpoints were initiated by an increase in slip rate on the basin-bounding fault, driven by linkage of the three main fault segments of the high-angle graben-bounding fault array. Fault interaction theory and ratios of channel steepness suggest that the slip rate enhancement factor on linkage was a factor of 3. We combine this information with geomorphic and structural constraints to estimate that linkage took place between 0.6 Ma and 1 Ma. Calculated pre- and post- linkage throw rates are 0.6 and 2 mm/yr respectively. Maximum plan-view knickpoint retreat rates upstream of the faults range from 4.5 to 28 mm/yr, and when normalised by drainage area, they are 2-7 times faster than for similar catchments upstream of normal faults in the Central Apennines of Italy and the Hatay Graben of Turkey. These knickpoint retreat rates imply a fluvial response time to fault growth and interaction of 1.6 to 2.7 My. However, marked along-strike disparities in retreat rates exist. We demonstrate that climate differences may explain the variation in rates between these study areas, but not within the Gediz graben itself. Consequently, we evaluate the extent to which measureable differences in bedrock lithology and erodibility modulate the propagation of
Mabuchi, K. [Meteorological Research Institute, Tsukuba (Japan); Takahashi, K. [Japan Meteorological Agency, Tokyo (Japan); Nasahara, K.N. [Univ. of Tsukuba (Japan). Inst. of Agricultural and Forest Engineering
The present state of environmental problems due to global warming resulting from increases of greenhouse gases has reached new levels. The international treaty known as the United Nations Framework Convention on Climate Change (UNFCCC) was adopted in 1992 to begin to consider what can be done to reduce global warming. The Kyoto Protocol, adopted in 1997 at the third Conference of the Parties to the UNFCCC (COP 3), proposed a worldwide reduction of greenhouse gas emission. Under these conditions, it became necessary to monitor the increases of greenhouse gases, especially carbon dioxide, and to conduct research to further understand the mechanisms of interactions between environmental changes and the carbon balance. Estimations of the carbon dioxide budget are of great importance in taking the proper steps to deal with increased concentrations due to anthropogenic emissions, and in predictions of future concentration levels. The main components of the carbon dioxide budget are anthropogenic emissions, atmospheric concentration, the exchange between the atmosphere and ocean, and the exchange between the atmosphere and terrestrial ecosystems. Among these components, the role of the terrestrial ecosystem is still uncertain, due to the heterogeneity of that system. Using a regional climate model that includes a terrestrial biosphere model, numerical simulations were performed to clarify the mechanism of the carbon cycle between the terrestrial ecosystem and the atmosphere and to investigate the climate factors impact on the carbon cycle in the East Asian terrestrial ecosystem. Model verifications were performed with regard to the principal elements: precipitation and vegetation phenology. The variations of the atmospheric carbon dioxide concentration simulated by the model were validated using the data at six in situ observatories. After the confirmations of the model performance, regional features of the impact of climate factors on the gross primary production (GPP
... in a place over a period of time. Climate change is major change in temperature, rainfall, snow, or ... by natural factors or by human activities. Today climate changes are occurring at an increasingly rapid rate. Climate ...
J Megan Steinweg
Full Text Available The activities of extracellular enzymes, the proximate agents of decomposition in soils, are known to depend strongly on temperature, but less is known about how they respond to changes in precipitation patterns, and the interaction of these two components of climate change. Both enzyme production and turnover can be affected by changes in temperature and soil moisture, thus it is difficult to predict how enzyme pool size may respond to altered climate. Soils from the Boston-Area Climate Experiment, which is located in an old field (on abandoned farmland, were used to examine how climate variables affect enzyme activities and microbial biomass carbon (MBC in different seasons and in soils exposed to a combination of three levels of precipitation treatments (ambient, 150% of ambient during growing season, and 50% of ambient year-round and four levels of warming treatments (unwarmed to ~4˚C above ambient over the course of a year. Warming, precipitation and season had very little effect on potential enzyme activity. Most models assume that enzyme dynamics follow microbial biomass, because enzyme production should be directly controlled by the size and activity of microbial biomass. We observed differences among seasons and treatments in mass-specific potential enzyme activity, suggesting that this assumption is invalid. In June 2009, mass-specific potential enzyme activity, using chloroform fumigation-extraction MBC, increased with temperature, peaking under medium warming and then declining under the highest warming. This finding suggests that either enzyme production increased with temperature or turnover rates decreased. Increased maintenance costs associated with warming may have resulted in increased mass-specific enzyme activities due to increased nutrient demand. Our research suggests that allocation of resources to enzyme production could be affected by climate-induced changes in microbial efficiency and maintenance costs.
In the present study, we investigated modeling and control of hydronic heat emitters integrated with a ground-source heat pump. Optimization of the system performance in terms of energy efficiency, associated energy cost and occupants' thermal comfort is the main objective to be fulfilled via de-sign of an integrated controller. We also proposed control strategies to manage energy consumption of the building to turn domestic heat demands into a flexible load in the smart electricity grid. We ...
Full Text Available Objectives. To investigate a prevalence of caries, filled permanentand extracted permanent teeth, as well as caries risk factors inschool children aged 7, 9 and 11.Methods. The survey included 800 children (296 children aged7; 254 children aged 9 and 250 children aged 11 from the MostarMunicipality, 400 of them living in both rural and urban areas.A dental mirror and standard light of dental chair were used forexamination. The DMF index (Dental Caries, Missing Teeth andFilled Teeth was determined, as well as failure in keeping teethhygiene, sugar intake with food, and incidence of oral cavity infection.Results. The dental state of permanent teeth in children aged 7and 9 has shown significant difference between the children fromrural and urban areas (p < 0,001. Out of 2,698 and 2,790 permanentteeth in children aged 11 from rural and urban areas, 1,086(40,25 % and 884 (31.68 % had caries, respectively (p < 0.01.The difference between these groups of children has been foundin relation to the index of oral hygiene too (p < 0.05.Conclusion. An identification of risk groups for getting caries wasvery important and could help health and social structures to maintaintheir programs in order to improve oral health.
Using the MARKAL simulation tool, different economic incentives in climate mitigation policy such as tradable emission permits, green certificates and carbon dioxide taxes have been analyzed. The analysis shows that there is an important advantage in applying the emission reductions internationally compared to a national policy, due to the varying marginal costs for the measures in different countries. The analysis also reveals at which price levels the Nordic countries as a whole become net sellers or net buyers of emission permits. The effects of combining emission permits with green certificates are analyzed, e.g. the inverse relation between permit and certificate prices. An appendix to the report gives a description of the Swedish energy system, emissions world-wide and examples of cost-effective mitigation measures for Sweden
Full Text Available Knowledge about grassland biomass and its dynamics is critical for studying regional carbon cycles and for the sustainable use of grassland resources. In this study, we investigated the spatio-temporal variation of biomass in the Xilingol grasslands of northern China. Field-based biomass samples and MODIS time series data sets were used to establish two empirical models based on the relationship of the normalized difference vegetation index (NDVI with above-ground biomass (AGB as well as that of AGB with below-ground biomass (BGB. We further explored the climatic controls of these variations. Our results showed that the biomass averaged 99.01 Tg (1 Tg=10(12 g over a total area of 19.6 × 10(4 km(2 and fluctuated with no significant trend from 2001 to 2012. The mean biomass density was 505.4 g/m(2, with 62.6 g/m(2 in AGB and 442.8 g/m(2 in BGB, which generally decreased from northeast to southwest and exhibited a large spatial heterogeneity. The year-to-year AGB pattern was generally consistent with the inter-annual variation in the growing season precipitation (GSP, showing a robust positive correlation (R(2=0.82, P<0.001, but an opposite coupled pattern was observed with the growing season temperature (GST (R(2=0.61, P=0.003. Climatic factors also affected the spatial distribution of AGB, which increased progressively with the GSP gradient (R(2=0.76, P<0.0001 but decreased with an increasing GST (R(2=0.70, P<0.0001. An improved moisture index that combined the effects of GST and GSP explained more variation in AGB than did precipitation alone (R(2=0.81, P<0.0001. The relationship between AGB and GSP could be fit by a power function. This increasing slope of the GSP-AGB relationships along the GSP gradient may be partly explained by the GST-GSP spatial pattern in Xilingol. Our findings suggest that the relationships between climatic factors and AGB may be scale-dependent and that multi-scale studies and sufficient long-term field data are needed
Laner, David; Cencic, Oliver; Svensson, Niclas; Krook, Joakim
Landfill mining has been proposed as an innovative strategy to mitigate environmental risks associated with landfills, to recover secondary raw materials and energy from the deposited waste, and to enable high-valued land uses at the site. The present study quantitatively assesses the importance of specific factors and conditions for the net contribution of landfill mining to global warming using a novel, set-based modeling approach and provides policy recommendations for facilitating the development of projects contributing to global warming mitigation. Building on life-cycle assessment, scenario modeling and sensitivity analysis methods are used to identify critical factors for the climate impact of landfill mining. The net contributions to global warming of the scenarios range from -1550 (saving) to 640 (burden) kg CO2e per Mg of excavated waste. Nearly 90% of the results' total variation can be explained by changes in four factors, namely the landfill gas management in the reference case (i.e., alternative to mining the landfill), the background energy system, the composition of the excavated waste, and the applied waste-to-energy technology. Based on the analyses, circumstances under which landfill mining should be prioritized or not are identified and sensitive parameters for the climate impact assessment of landfill mining are highlighted. PMID:27282202
Full Text Available Background: Geographic distribution of West Nile virus (WNV is heterogeneous in Iran by a high circulation in the southern-western areas. The objective of our study was to determine environmental and climatic factors associated with the risk of WNV equine seropositivity in Iran.Methods: Serological data were obtained from a serosurvey conducted in equine population in 260 districts in Iran. The climate and environmental parameters included in the models were distance to the nearest wetland area, type of stable, Normalized Difference Vegetation Index (NDVI, annual mean temperature, humidity and precipitation.Results: The important risk factors included annual mean temperature, distance to wetlands, local and seasonal NDVI differences. The effect of local NDVI differences in spring was particularly notable. This was a normalized difference of average NDVI between two areas: a 5 km radius area centered on the stable and the 5–10 km surrounding area.Conclusion: The model indicated that local NDVI’s contrast during spring is a major risk factor of the transmission of West-Nile virus in Iran. This so-called oasis effect consistent with the seasonal production of vegetation in spring, and is associated to the attractiveness of the local NDVI environment for WNV vectors and hosts.
LIU Xiaomang; ZHENG Hongxing; ZHANG Minghua; LIU Changming
Despite the observed increase in global temperature,observed pan evaporation in many regions has been decreasing over the past 50 years,which is known as the “pan evaporation paradox”.The “pan evaporation paradox” also exists in the Tibetan Plateau,where pan evaporation has decreased by 3.06 mm a-2 (millimeter per annum).It is necessary to explain the mechanisms behind the observed decline in pan evaporation because the Tibetan Plateau strongly influences climatic and environmental changes in China,Asia and even in the Northern Hemisphere.In this paper,a derivation based approach has been used to quantitatively assess the contribution rate of climate factors to the observed pan evaporation trend across the Tibetan Plateau.The results showed that,provided the other factors remain constant,the increasing temperature should have led to a 2.73 mm a-2 increase in pan evaporation annually,while change in wind speed,vapor pressure and solar radiation should have led to a decrease in pan evaporation by 2.81 mm a-2,1.96 mm a-2 and 1.11 mm a-2 respectively from 1970 to 2005.The combined effects of the four climate variables have resuited in a 3.15 mm a-2 decrease in pan evaporation,which is close to the observed pan evaporation trend with a relative error of 2.94%.A decrease in wind speed was the dominant factor for the decreasing pan evaporation,followed by an increasing vapor pressure and decreasing solar radiation,all of which offset the effect of increasing temperature across the Tibetan Plateau.
Full Text Available The pilot researches were conducted in Wielkopolska. They aimed initial identifi cation of cows reaction on changing of THI, which are likened to temperature and humidity conditions of air. The subjected cows characterize with high productivity, exceeding 40kg of milk per day, independently from lactation stages. The results display that the day s production of raw milk, as well as fat and protein content, do not only depend on lactation stage but also on the value of THI factors. Higher THI is accompanied by loss in the weight of milk and drop in its technological utility. The climate warming may escalate the risk of production loss during the heats.
Humbert, Guillaume; Jaffrezic, Anne; Fovet, Ophélie; Gruau, Gérard; Durand, Patrick
Dissolved organic matter (DOM) is a key form of the organic matter linking together the water and the carbon cycles and interconnecting the biosphere (terrestrial and marine) and the soil. At the landscape scale, land use and hydrology are the main factors controlling the amount of DOM transferred from soils to the stream. In an intensively cultivated catchment, a recent work using isotopic composition of DOM as a marker has identified two different sources of DOM. The uppermost soil horizons of the riparian wetland appear as a quasi-infinite source while the topsoil of the hillslope forms a limited one mobilized by water-table rise and exported to the stream across the upland-riparian wetland-stream continuum. In addition to the exportation of DOM via water fluxes, climatic factors like temperature and precipitation regulate the DOM production by influencing microbial activity and soil organic matter degradation. The small headwater catchment (5 km²) of Kervidy-Naizin located in Brittany is part of the Environment Research Observatory (ORE) AgrHys. Weather and the hydro-chemistry of the stream, and the groundwater levels are daily recorded since 1993, 2000 and 2001 respectively. Over 13 contrasted hydrological years, the annual flow weighted mean concentration of dissolved organic carbon (DOC) is 5.6 mg.L-1 (sd = 0.7) for annual precipitation varying from 488mm to 1327mm and annual mean temperatures of 11°C (sd = 0.6). Based on this considerable dataset and this annual variability, we tried to understand how the hydro-climatic conditions determinate the stream DOC concentrations along the year. From the fluctuations of water table depth, each hydrologic year has been divided into three main period: i) progressive rewetting of the riparian wetland soils, ii) rising and holding high of the water table in the hillslope, iii) drawdown of the water-table, with less and less topsoil connected to the stream. Within each period base flow and storm flow data were first
Full Text Available Background: With a warming climate, it is important to identify sub-populations at risk of harm during extreme heat. Several international studies have reported that individuals from ethnic minorities are at increased risk of heat-related illness, for reasons that are not often discussed. Objective: The aim of this article is to investigate the underpinning reasons as to why ethnicity may be associated with susceptibility to extreme heat, and how this may be relevant to Australia's population. Design: Drawing upon literary sources, the authors provide commentary on this important, yet poorly understood area of heat research. Results: Social and economic disparities, living conditions, language barriers, and occupational exposure are among the many factors contributing to heat-susceptibility among minority ethnic groups in the United States. However, there is a knowledge gap about socio-cultural influences on vulnerability in other countries. Conclusion: More research needs to be undertaken to determine the effects of heat on tourists, migrants, and refugees who are confronted with a different climatic environment. Thorough epidemiological investigations of the association between ethnicity and heat-related health outcomes are required, and this could be assisted with better reporting of nationality data in health statistics. Climate change adaptation strategies in Australia and elsewhere need to be ethnically inclusive and cognisant of an upward trend in the proportion of the population who are migrants and refugees.
Gu, Haogao; Leung, Ross Ka-Kit; Jing, Qinlong; Zhang, Wangjian; Yang, Zhicong; Lu, Jiahai; Hao, Yuantao; Zhang, Dingmei
Dengue fever (DF) is endemic in Guangzhou and has been circulating for decades, causing significant economic loss. DF prevention mainly relies on mosquito control and change in lifestyle. However, alert fatigue may partially limit the success of these countermeasures. This study investigated the delayed effect of meteorological factors, as well as the relationships between five climatic variables and the risk for DF by boosted regression trees (BRT) over the period of 2005-2011, to determine the best timing and strategy for adapting such preventive measures. The most important meteorological factor was daily average temperature. We used BRT to investigate the lagged relationship between dengue clinical burden and climatic variables, with the 58 and 62 day lag models attaining the largest area under the curve. The climatic factors presented similar patterns between these two lag models, which can be used as references for DF prevention in the early stage. Our results facilitate the development of the Mosquito Breeding Risk Index for early warning systems. The availability of meteorological data and modeling methods enables the extension of the application to other vector-borne diseases endemic in tropical and subtropical countries. PMID:27589777
Pouyan, S.; Ganji, A.; Behnia, P.
Wind erosion climatic erosivity is a measure of the climatic tendency to produce conditions conducive to wind erosion. This research develops a method to determine the regional climate's tendency to cause wind erosion on the basis of a physically based climatic factor (CE) and linear moment analysis (L-moments) in Fars province, southwest Iran. CE is calculable from wind speed quantiles and other available meteorological data. The wind quantiles can be estimated by a frequency analysis of the available wind data. Wind speed data are often either not available or are of short record length, and thus, CE estimates from such data have large standard errors. In such a situation, data from several sites can be used to estimate wind speed quantiles at each site based on a regional frequency analysis. Monthly averages of maximum daily wind speed of 19 meteorological stations in Fars province were used for regional analysis. Based on L-moment analysis, two homogeneous regions were determined. Regional wind speed quantiles were calculated, and the results were used to calculate CE values for two 6-month wet and dry periods for each homogeneous region. Furthermore, CE values were estimated for each station in the study area using a Weibull distribution, and the results were compared with the regional-based CE values. It showed that CE values estimated using the regional-based approach have smaller sampling variance compared to those obtained from the Weibull method. The proposed method can be used to evaluate the regional risk of wind erosion in arid and semi-arid environments.
The Intergovernmental Panel on Climate Change (IPCC) and the US Environmental Protection Agency (EPA) have suggested that increased use of natural gas is a possible strategy for reducing the potential for global warming. Carbon dioxide (CO2) contributes as much to global warming as all other greenhouse gases combined. During combustion, natural gas generates less CO2 per unit of energy produced than either coal or oil. On the basis of the amount of CO2 emitted, the potential for global warming could be reduced by substituting natural gas to coal or oil. However, since natural gas is primarily methane, a potent greenhouse gas, these emissions could reduce natural gas's inherent advantage of lower CO2 emissions. To address this issue and compare the fuels on an equivalent basis, it is necessary to account for emissions of all greenhouse gases throughout the fuel cycle of each fuel and to determine the impact of these gases on global warming. Gas Research Institute and EPA jointly funded a study to quantify methane emissions from the natural gas industry so that this information could be used as input to address the issue of the fuel switching strategy. The study found that the natural gas industry emitted 1.4% of natural gas production (314 Bscf of methane) to the atmosphere in 1992. Today, due to voluntary reductions from the gas industry, the percent leaked is even less. This 1992 amount has been analyzed over a broad range of global warming potentials, and the conclusion that fuel switching to natural gas reduces the potential for global warming is supported. The results of this study are presented in this paper
Iida, Ryosuke; Koketsu, Yuzo
Objectives were to determine climatic and production factors associated with abortions in commercial swine herds and to compare the reproductive performances and culling patterns between aborting and non-aborting females that were re-inseminated. There were 309,427 service records analyzed for 56,375 females entered into 100 herds. Climate data were obtained from 21 weather stations located close to the herds. Mean daily average temperatures (Tavg) for the 21-day pre-mating period for each female were combined with the female's reproductive data. Generalized linear model assessments were conducted for abortion risk per service. Abortion risk per service (±SE) was 0.7±0.06%, and mean value of Tavg (range) was 15.0 °C (-10.7 to 32.7 °C). Risk factors associated with an increased abortion risk per service were greater numbers of parities, delivering more stillbirth fetuses, greater mean Tavg for the 21-day pre-mating periods and re-servicing of females that did not get pregnant at the first servicing (Pcooling systems. PMID:25906679
By comparing five ecosystem types in the Czech Republic over several years, we recorded the highest carbon sequestration potential in an evergreen Norway spruce forest (100%) and an agroecosystem (65%), followed by European beech forest (25%) and a wetland ecosystem (20%). Because of a massive ecosystem respiration, the final carbon gain of the grassland was negative. Climate was shown to be an important factor of carbon uptake by ecosystems: by varying the growing season length (a 22-d longer season in 2005 than in 2007 increased carbon sink by 13%) or by the effect of short- term synoptic situations (e.g. summer hot and dry days reduced net carbon storage by 58% relative to hot and wet days). Carbon uptake is strongly affected by the ontogeny and a production strategy which is demonstrated by the comparison of seasonal course of carbon uptake between coniferous (Norway spruce) and deciduous (European beech) stands. - Highlights: → Highest carbon sequestration potential in evergreen Norway spruce forest (100%) and an agroecosystem (65%), followed by European beech forest (25%) and a wetland ecosystem (20%). → The final carbon gain of the grassland was negative (massive ecosystem respiration). → Climate is important factor of net primary productivity. → Carbon uptake is strongly affected by the ontogeny and a production strategy of ecosystem. - Identification of the apparent differences in the carbon storage by different ecosystem types.
Larsen, Poul Klenz [The National Museum, Copenhagen (Denmark). Dept. of Conservation; Brostroem, Tor [Gotland Univ., Visby (Sweden)
Conservation heating has been used for decades to control the RH in cultural heritage buildings. But if the building is not used for living or working, heating is not needed for human comfort. The chemical decay of organic materials depends mainly on temperature, so it is better for preservation to reduce heating. The air exchange rate is related to the design of the building envelope. With rising energy prices humidity control by dehumidification may be an attractive alternative. The potential for energy efficient RH control was examined for a generic building exposed to the monthly average outside temperature and RH in Denmark. The indoor temperature was allowed to follow the outside average, whereas the indoor RH was controlled to 40 % 50 % 60 % or 70 %. Dehumidification was implemented in three different buildings: A recent museum store, a medieval church, and an 18th century country mansion. The energy consumption depends on the RH set point, the air exchange rate and the source of liquid moisture to the building. The air exchange rate related to the design of the building envelope. Single glazed windows and doors are the most important sources of leakage to buildings. Lack of maintenance may lead to poor performance of the dehumidifier and waste energy. (orig.)
Jacobs, P.; Gids, W.F. de
A new concept for aircraft cabin climatisation has been developed in which the seat is the main Indoor Air Quality (IAQ) and temperature control system for the passengers containing provisions for local supply and local exhaust of air. Direct supply of clean outside air in the breathing zone, throug
Kovalenko, Vladimir A.; Zherebtsov, Gelii A.
Presented is the evidence for the actual manifestation of solar variability in climatic characteristics of the Prebaikalye. This influence on surface air temperature was quantified. A high degree of correlation was established between the mean power of a solar activity cycle and the surface air temperature in the Prebaikalye, averaged over a solar cycle period. It is shown that the main meaningful air temperature variations in the region for the period 1881-1960 were caused by solar activity. The temperature variation amplitude for that period was 1°C. Since the 1960s until the present, with the influence of solar variability persisting, there has been an obvious forcing of another factor whose role was steadily increasing so that as recently as in the last decade it exceeded the contribution from solar variability. For the period 1960-1997, the temperature rise that was not associated with solar variability, was 1.7°C. This new factor is most likely to be the global variations of the thermal regime of the atmosphere that are caused by the anthropogenic factor. This assumption is in agreement with model calculations, pointing to the fact that the most significant manifestation of a global warming should be expected in inland regions of Eurasia. An analysis of the seasonal variations in ground temperature showed that the variations that are taking place to date are most clearly pronounced in the winter-spring period and are associated with a reduction of the stationary period of the Siberian anticyclone. This suggests that the mechanism responsible for the realization of variability factors of regional climate is the global atmospheric circulation rather than a local change of the energy balance of the atmosphere.
Dino Roberto Soares De Lorenzi
Full Text Available OBJETIVO: identificar fatores indicadores da sintomatologia climatérica. PACIENTES E MÉTODOS: estudo transversal de 254 mulheres pós-menopáusicas com idade entre 45 e 60 anos atendidas em Ambulatório de Climatério entre junho e outubro de 2002. Foram excluídas mulheres histerectomizadas ou sob terapia hormonal. As atitudes sobre a menopausa foram avaliadas por meio de instrumento construído a partir da adaptação de um questionário, constituindo-se de 11 questões referentes a atitudes positivas (vantagens e 11 referentes a atitudes negativas (desvantagens sobre a menopausa. Para a coleta de dados sociodemográficos e relacionados a variáveis reprodutivas e às condições de saúde da população estudada, utilizou-se questionário estruturado e previamente testado. A sintomatologia climatérica foi avaliada pelo índice de Kupperman e as atitudes sobre a menopausa por meio de instrumento específico. Os dados foram analisados pelo teste t de Student, análise de variância (ANOVA e regressão linear múltipla. RESULTADOS: de modo geral, a sintomatologia climatérica foi leve em 28%, moderada em 42,3% e intensa em 30,7% dos casos. Os sintomas mais prevalentes foram a irritabilidade (87,1%, as artralgias/mialgias (77,5% e a melancolia/tristeza (73,2%, ao passo que os mais intensos foram as ondas de calor, a irritabilidade e a insônia. Sintomas vasomotores foram referidos por 60,2% das entrevistadas. Mostraram-se indicadores da sintomatologia climatérica a cor, a atividade física regular e as atitudes com respeito a menopausa. A cor branca (p=0,02, a atividade física regular (p=0,04 e uma percepção positiva sobre a menopausa (p=0,01 associaram-se a sintomas climatéricos menos intensos. Em contrapartida, a percepção da menopausa como evento desvantajoso (atitude negativa associou-se a pior sintomatologia climatérica (pPURPOSE: to identify factors associated with climacteric symptoms. METHODS: a cross-sectional study of 254
Plavcová, Eva; Kyselý, Jan
Bern: Swiss Climate Research, 2011, s. 84-85. [International NCCR Climate Summer School "Climate Change, Extremes and Ecosystem Services" /10./. Grindelwald (CH), 04.09.2001-09.09.2011] R&D Projects: GA ČR GAP209/10/2265 Institutional research plan: CEZ:AV0Z30420517 Keywords : regional climate models * air temperature * atmospheric circulation * future climate change scenarios Subject RIV: DG - Athmosphere Sciences, Meteorology
The techniques to control temperature and humidity to reduce failures in semiconductor devices are presented. The maximum operating junction temperature affects the electronic system reliability, and the equation for the junction temperature of the device shows that internal and external thermal resistances affect component life. Junction temperature reductions up to 60 C were achieved by the development of heat pipes for microcircuits, which will enhance electronics life by 32 times. Humidity control by improved sealing and use of heaters to prevent moisture condensation proved difficult and costly, and high pressure dehydrators were heavy and expensive. Therefore, low pressure dehydrator was developed which is smaller, lighter, and less expensive. The development of low pressure dehumidifying system including test data is presented
Waller, Eric Kindseth
ABSTRACTComplexity in Climatic Controls on Plant Species Distribution: Satellite Data Reveal Unique Climate for Giant Sequoia in the California Sierra NevadabyEric Kindseth WallerDoctor of Philosophy in Environmental Science, Policy, and ManagementUniversity of California, BerkeleyProfessor Dennis D. Baldocchi, ChairA better understanding of the environmental controls on current plant species distribution is essential if the impacts of such diverse challenges as invasive species, changing fir...
Lu, Xinmin; Siemann, Evan; He, Minyan; Wei, Hui; Shao, Xu; Ding, Jianqing
Climate change may shift interactions of invasive plants, herbivorous insects and native plants, potentially affecting biological control efficacy and non-target effects on native species. Here, we show how climate warming affects impacts of a multivoltine introduced biocontrol beetle on the non-target native plant Alternanthera sessilis in China. In field surveys across a latitudinal gradient covering their full distributions, we found beetle damage on A. sessilis increased with rising temperature and plant life history changed from perennial to annual. Experiments showed that elevated temperature changed plant life history and increased insect overwintering, damage and impacts on seedling recruitment. These results suggest that warming can shift phenologies, increase non-target effect magnitude and increase non-target effect occurrence by beetle range expansion to additional areas where A. sessilis occurs. This study highlights the importance of understanding how climate change affects species interactions for future biological control of invasive species and conservation of native species. PMID:25376303
A survey oriented towards identifying the human factors issues in regard to the use of advanced instrumentation and controls (I ampersand C) in the nuclear industry was conducted. A number of United States (US) and Canadian nuclear vendors and utilities were participants in the survey. Human factors items, subsumed under the categories of computer-generated displays (CGD), controls, organizational support, training, and related topics, were discussed. The survey found the industry to be concerned about the human factors issues related to the implementation of advanced I ampersand C. Fifteen potential human factors problems were identified. They include: the need for an advanced I ampersand C guideline equivalent to NUREG-0700; a role change in the control room from operator to supervisor; information overload; adequacy of existing training technology for advanced I ampersand C; and operator acceptance and trust. 11 refs., 1 tab
A survey oriented towards identifying the human factors issues in regard to the use of advanced instrumentation and controls (I C) in the nuclear industry was conducted. A number of United States (US) and Canadian nuclear vendors and utilities were participants in the survey. Human factors items, subsumed under the categories of computer-generated displays (CGD), controls, organizational support, training, and related topics, were discussed. The survey found the industry to be concerned about the human factors issues related to the implementation of advanced I C. Fifteen potential human factors problems were identified. They include: the need for an advanced I C guideline equivalent to NUREG-0700; a role change in the control room from operator to supervisor; information overload; adequacy of existing training technology for advanced I C; and operator acceptance and trust. 11 refs., 1 tab.
Rogers, Evan D.; And Others
Four recent factor analytic studies of the Litwin and Stringer Organizational Climate Questionnaire (LSOCQ) are compared. Although there is somewhat more intra- than inter-organizational replicability of factors, both comparisons raise considerable doubt about the validity of the Litwin and Stringer instrument. (Author)
Yin, Xiaogang; Jabloun, Mohamed; Olesen, Jørgen Eivind;
Drought risk is considered to be among the main limiting factors for maize (Zea mays L.) production in the Northeast Farming Region of China (NFR). Maize yield data from 44 stations over the period 1961–2010 were combined with data from weather stations to evaluate the effects of climatic factors...
Since the Three Mile Island accident two ways for improving the Human-Machine Interface have mainly been followed: the development of computerized operator aids in existing control-rooms and the design of advanced control-rooms. Insufficient attention paid to human factors in the design of operator aids has generally led to these aids being neglected or unused by their potential users. While for the design of advanced control-rooms efforts have been made for dealing with human factors in more extensive way. Based upon this experience, a general method for taking account of human factors in a control-room design has been devised and is described in this paper. (author)
Carol, Eleonora S; Alvarez, María Del Pilar; Borzi, Guido E
The formation of evaporites associated with the final stages of the precipitation sequence, such as the case of halite, is frequent in marshes in arid areas, but it is not to be expected in those humid climates. This work, by means of the study of the hydrological, climatic and land use conditions, identifies the factors that allow the formation of saline precipitations in a marsh located in a humid climate area. The results obtained show that the exclusion of the marsh as a result of the embankment is the main reason for the presence of halite. It is to be expected that in the future the growth of the embanked marsh areas, together with the climatic and tidal condition tendencies recorded, will favour a higher rate of formation of evaporite salts. The identification of these factors makes it possible to set basic sustainable management guidelines to avoid soil salinisation. PMID:27021624
Abstract: Despite the fact that permafrost soils contain up to half of the carbon (C) in terrestrial pools, we have a poor understanding of the controls on decomposition in thawed permafrost. Global climate models assume that decomposition increases linearly with temperature, yet decomposition in th...
Straten, van G.; Willigenburg, van L.G.; Tap, R.F.
While a tomato crop grows on the time-scale of weeks, the greenhouse climate changes on a time-scale of minutes. The economic optimal control problem of producing good quality crops against minimum input of resources is tackled by a two time-scale decomposition. First, the sub-problem associated to
De Persis, C.; Jessen, Jan Jacob; Izadi-Zamanabadi, Roozbeh; Schiøler, Henrik
of each zone is strongly affected by those in the neighbor zones. We discuss a control strategy which, by acting on the heating and ventilation devices of the overall system, is able to achieve the control task while efficiently managing the internal flow. It is pointed out that the controller is......In this contribution, we examine a dynamic model describing the evolution of internal climate conditions in a closed environment partitioned into zones for which different climate conditions must be guaranteed. The zones are not separated, large air masses are exchanged among them, and the behavior...... hybrid and decentralized. An additional feature of the controller is that it takes on values in a finite set. The possible implementation in a networked environment is briefly discussed....
Iraj Soltani; Mostafa Aghahosseini; Nahid Akbari
This study aimed to examine the employees' views about the organizational climate dimensions and motivational factors and explain their relationship in the Blood Transfusion Organization's employees. Eighty-seven subjects as the population were selected from all parts of the organization. The research tools included the questionnaires of organizational climate, motivational potential dimensions (job identification), and the needs. According to goals and questions, the data from the research q...
Gonçalves, Leonel C.; Endrass, Jérôme; Rossegger, Astrid; Dirkzwager, Anja J. E.
Background Despite the high prevalence rate of mental health problems among young prisoners, little is known about the longitudinal course and covariates of their mental health symptoms during incarceration, especially the influence of the correctional climate. The current study aimed: (1) to examine changes in young prisoners’ mental health symptoms during incarceration, (2) to identify personal factors associated with their mental health symptoms and perceptions of the correctional climate,...
Gonçalves, Leonel C.; Endrass, Jérôme; Rossegger, Astrid; Dirkzwager, Anja J. E.
BackgroundDespite the high prevalence rate of mental health problems among young prisoners, little is known about the longitudinal course and covariates of their mental health symptoms during incarceration, especially the influence of the correctional climate. The current study aimed: (1) to examine changes in young prisoners’ mental health symptoms during incarceration, (2) to identify personal factors associated with their mental health symptoms and perceptions of the correctional climate, ...
Maria Virginia Flores-Oritz; Alfonso Vega-Lopez; Edgar ARmando Chavez-Moreno
This paper investigates the relationship that exists between organizational climate as a factor of competitiveness in the franchising of fast food in Tijuana, BC. No doubt the primary asset of the organization is the human resource since it is through a good working team that the company achieves its objectives and goals. This ensures their development and market positioning and does not leave aside the organizational climate and the importance it has within the companies. Here the purpose of...
Low temperature hydronic heating and cooling systems connected to renewable energy sources have gained more attention in the recent decades. This is due to the growing public awareness of the adverse environmental impacts of energy generation using fossil fuel. Radiant hydronic sub-floor heating...... pipes and radiator panels are two examples of such systems that have reputation of improving the quality of indoor thermal comfort compared to forced-air heating or cooling units. Specifically, a radiant water-based sub-floor heating system is usually combined with low temperature heat sources, among...... which geothermal heat pump, solar driven heat pumps and the other types are categorized as renewable or renewable energy sources. In the present study, we investigated modeling and control of hydronic heat emitters integrated with a ground-source heat pump. Optimization of the system performance...
Padfield, Tim; Ryhl-Svendsen, Morten; Klenz Larsen, Poul;
The small archive of the Arnamagnæan Institute is almost passively air conditioned by being placed between a corridor in a permanently warm Copenhagen university building and the outer wall of the building. It is well insulated towards the warmed building and thinly insulated towards the outside......, so that its temperature is approximately one third of the way between the building interior temperature and the running average outside temperature. The annual average temperature in the archive is above the annual average outside so that the annual average relative humidity (RH) is automatically...... lower than that outside: it is about 50%. The day to day RH remains steady over the entire year because of humidity buffering by the walls and by the hygroscopic content of the archive. Fine control of the RH is provided by pumping in outside air when it is, by chance, of the right water vapour content...
Chen, X.; Bohn, T. J.; Lettenmaier, D. P.
Climate factors including soil temperature and moisture, incident solar radiation, and atmospheric carbon dioxide concentration are important environmental controls on methane (CH4) emissions from northern wetlands. We investigated the spatiotemporal distributions of the influence of these factors on northern high-latitude wetland CH4 emissions using an enhanced version of the Variable Infiltration Capacity (VIC) land surface model. We simulated CH4 emissions from wetlands across the pan-Arctic domain over the period 1948-2006, yielding annual average emissions of 36.1 ± 6.7 Tg CH4 yr-1 for the period 1997-2006. We characterized historical sensitivities of CH4 emissions to air temperature, precipitation, incident long- and shortwave radiation, and atmospheric [CO2] as a function of average summer air temperature and precipitation. Emissions from relatively warm and dry wetlands in the southern (permafrost-free) portion of the domain were positively correlated with precipitation and negatively correlated with air temperature, while emissions from wetter and colder wetlands further north (permafrost) were positively correlated with air temperature. Over the entire period 1948-2006, our reconstructed CH4 emissions increased by 20 %, the majority of which can be attributed to an increasing trend in summer air temperature. We estimated future emissions in response to 21st century warming as predicted by CMIP5 (Coupled Model Intercomparison Project Phase 5) model projections to result in end-of-century CH4 emissions 38-53 % higher than our reconstructed 1997-2006 emissions, accompanied by the northward migration of warmer and drier than optimal conditions for CH4 emissions, implying a reduced role for temperature in driving future increases in emissions.
Fleming, J. R.
This presentation examines the history of large-scale weather and climate engineering since 1840, with special reference to imaginative and speculative literature and with special relevance to ethical and policy issues. Ultimate control of the weather and climate embodies both our wildest fantasies and our greatest fears. Fantasy often informs reality (and vice-versa). NASA managers know this well, as do Trekkies. The best science fiction authors typically build from the current state of a field to construct futuristic scenarios that reveal and explore the human condition. Scientists as well often venture into flights of fancy. Though not widely documented, the fantasy-reality axis is also a prominent aspect of the history of the geosciences. James Espy's proposal in the 1840s to enhance precipitation by lighting huge fires, thus stimulating convective updrafts, preceded the widespread charlatanism of the rain-makers, or so-called "pluviculturalists," in the western U.S. One hundred years later, promising discoveries in "cloud seeding" by Irving Langmuir and his associates at the General Electric Corporation rapidly devolved into unsupportable proposals and questionable practices by military and commercial rain-makers seeking to control the weather. During the Cold War, Soviet engineers also promoted a chilling vision (to Westerners) of global climate control. Recently, rather immodest proposals to "fix" a climate system perceived to be out of control have received wide circulation. In 2003 the U.S. Pentagon released a report recommending that the government should "explore geo-engineering options that control the climate." In 2004 a symposium in Cambridge, England set out to "identify, debate, and evaluate" possible, but highly controversial options for the design and construction of engineering projects for the management and mitigation of global climate change. This talk will locate the history of weather and climate modification within a long tradition of
Caldwell, M M; Bornman, J F; Ballaré, C L; Flint, S D; Kulandaivelu, G
, such as diminished growth, acclimation responses of plants to UV-B radiation and interactions of plants with consumer organisms such as insects and plant pathogens. The response to UV-B radiation involves both the initial stimulus by solar radiation and transmission of signals within the plants. Resulting changes in gene expression induced by these signals may have elements in common with those elicited by other environmental factors, and generate overlapping functional (including acclimation) responses. Concurrent responses of terrestrial systems to the combination of enhanced UV-B radiation and other global change factors (increased temperature, CO2, available nitrogen and altered precipitation) are less well understood. Studies of individual plant responses to combinations of factors indicate that plant growth can be augmented by higher CO2 levels, yet many of the effects of UV-B radiation are usually not ameliorated by the elevated CO2. UV-B radiation often increases both plant frost tolerance and survival under extreme high temperature conditions. Conversely, extreme temperatures sometimes influence the UV-B radiation sensitivity of plants directly. Plants that endure water deficit stress effectively are also likely to be tolerant of high UV-B flux. Biologically available nitrogen is exceeding historical levels in many regions due to human activities. Studies show that plants well supplied with nitrogen are generally more sensitive to UV-B radiation. Technical issues concerning the use of biological spectral weighting functions (BSWFs) have been further elucidated. The BSWFs, which are multiplication factors assigned to different wavelengths giving an indication of their relative biological effectiveness, are critical to the proper conduct and interpretation of experiments in which organisms are exposed to UV radiation, both in the field and in controlled environment facilities. The characteristics of BSWFs vary considerably among different plant processes, such
Marek, Michal V; Janouš, Dalibor; Taufarová, Klára; Havránková, Kateřina; Pavelka, Marian; Kaplan, Věroslav; Marková, Irena
By comparing five ecosystem types in the Czech Republic over several years, we recorded the highest carbon sequestration potential in an evergreen Norway spruce forest (100%) and an agroecosystem (65%), followed by European beech forest (25%) and a wetland ecosystem (20%). Because of a massive ecosystem respiration, the final carbon gain of the grassland was negative. Climate was shown to be an important factor of carbon uptake by ecosystems: by varying the growing season length (a 22-d longer season in 2005 than in 2007 increased carbon sink by 13%) or by the effect of short- term synoptic situations (e.g. summer hot and dry days reduced net carbon storage by 58% relative to hot and wet days). Carbon uptake is strongly affected by the ontogeny and a production strategy which is demonstrated by the comparison of seasonal course of carbon uptake between coniferous (Norway spruce) and deciduous (European beech) stands. PMID:21345558
Bassu, Simona; Brisson, Nadine; Grassini, Patricio; Durand, Jean-Louis; Boote, Kenneth; Lizaso, Jon; Jones, James W.; Rosenzweig, Cynthia; Ruane, Alex C.; Adam, Myriam; Baron, Christian; Basso, Bruno; Biernath, Christian; Boogaard, Hendrik; Conijn, Sjaak; Corbeels, Marc; Deryng, Delphine; DeSanctis, Giacomo; Gayler, Sebastian; Grassini, Patricio; Hatfield, Jerry; Hoek, Steven; Izaurralde, Cesar; Jongschaap, Raymond; Kemanian, Armen R.; Kersebaum, K. Christian
Potential consequences of climate change on crop production can be studied using mechanistic crop simulation models. While a broad variety of maize simulation models exist, it is not known whether different models diverge on grain yield responses to changes in climatic factors, or whether they agree in their general trends related to phenology, growth, and yield. With the goal of analyzing the sensitivity of simulated yields to changes in temperature and atmospheric carbon dioxide concentrations [CO2], we present the largest maize crop model intercomparison to date, including 23 different models. These models were evaluated for four locations representing a wide range of maize production conditions in the world: Lusignan (France), Ames (USA), Rio Verde (Brazil) and Morogoro (Tanzania). While individual models differed considerably in absolute yield simulation at the four sites, an ensemble of a minimum number of models was able to simulate absolute yields accurately at the four sites even with low data for calibration, thus suggesting that using an ensemble of models has merit. Temperature increase had strong negative influence on modeled yield response of roughly -0.5 Mg ha(sup 1) per degC. Doubling [CO2] from 360 to 720 lmol mol 1 increased grain yield by 7.5% on average across models and the sites. That would therefore make temperature the main factor altering maize yields at the end of this century. Furthermore, there was a large uncertainty in the yield response to [CO2] among models. Model responses to temperature and [CO2] did not differ whether models were simulated with low calibration information or, simulated with high level of calibration information.
J. H. Carver
Full Text Available A CO2-weathering model has been used to explore the possible evolution of the Earth's climate as the Sun steadily brightened throughout geologic time. The results of the model calculations can be described in terms of three, qualitatively different, "Megaclimates". Mega-climate 1 resulted from a period of rapid outgassing in the early Archean, with high, but declining, temperatures caused by the small weathering rates on a largely water-covered planet. Mega-climate 2 began about 3 Gyear ago as major continental land masses developed, increasing the weathering rate in the early Proterozoic and thereby depleting the atmospheric CO2 concentration. This process produced the first Precambrian glaciations about 2.3 Gyear ago. During Mega-climate 2, evolutionary biological processes increased the surface weatherability in incremental steps and plate tectonics modulated the CO2 outgassing rate with an estimated period of 150 Myear (approximately one-half the period for the formation and breakup of super continents. Throughout Mega-climate 2 the surface temperature was controlled by variations in the atmospheric CO2 level allowing transitions between glacial and non-glacial conditions. The results of the model for Mega-climate 2 are in agreement with the occurrence (and absence of glaciations in the geologic record. Extending the model to the future suggests that CO2 control of the Earth's temperature will no longer be able to compensate for a solar flux that continues to increase. The present level of atmospheric CO2 is so small that further reduction in CO2 cannot prevent the Earth from experiencing Mega-climate 3 with steadily increasing surface temperatures caused by the continued brightening of the Sun. During Mega-climate 3, the main danger to the biosphere would come not from an increasing temperature but from a decreasing (rather than an increasing CO2
Harmful (toxic, food web altering, hypoxia generating) cyanobacterial algal blooms (CyanoHABs) are proliferating world-wide due to anthropogenic nutrient enrichment, and they represent a serious threat to the use and sustainability of our freshwater resources. Traditionally, phosphorus (P) input reductions have been prescribed to control CyanoHABs, because P limitation is widespread and some CyanoHABs can fix atmospheric nitrogen (N2) to satisfy their nitrogen (N) requirements. However, eutrophying systems are increasingly plagued with non N2 fixing CyanoHABs that are N and P co-limited or even N limited. In many of these systems N loads are increasing faster than P loads. Therefore N and P input constraints are likely needed for long-term CyanoHAB control in such systems. Climatic changes, specifically warming, increased vertical stratification, salinization, and intensification of storms and droughts play additional, interactive roles in modulating CyanoHAB frequency, intensity, geographic distribution and duration. In addition to having to consider reductions in N and P inputs, water quality managers are in dire need of effective tools to break the synergy between nutrient loading and hydrologic regimes made more favorable for CyanoHABs by climate change. The more promising of these tools make affected waters less hospitable for CyanoHABs by 1) altering the hydrology to enhance vertical mixing and/or flushing and 2) decreasing nutrient fluxes from organic rich sediments by physically removing the sediments or capping sediments with clay. Effective future CyanoHAB management approaches must incorporate both N and P loading dynamics within the context of altered thermal and hydrologic regimes associated with climate change. - Research Highlights: → Toxic cyanobacterial blooms (CyanoHABs) increasingly threaten global water supplies. → Human (nutrient) and climate (hydrology, temperature) changes synergistically promote CyanoHABs. → CyanoHAB control involves
Persiano, Simone; Castellarin, Attilio; Salinas, Jose Luis; Domeneghetti, Alessio; Brath, Armando
The growing concern about the possible effects of climate change on flood frequency regime is leading Authorities to review previously proposed reference procedures for design-flood estimation, such as national flood frequency models. Our study focuses on Triveneto, a broad geographical region in North-eastern Italy. A reference procedure for design flood estimation in Triveneto is available from the Italian NCR research project "VA.PI.", which considered Triveneto as a single homogeneous region and developed a regional model using annual maximum series (AMS) of peak discharges that were collected up to the 1980s by the former Italian Hydrometeorological Service. We consider a very detailed AMS database that we recently compiled for 76 catchments located in Triveneto. All 76 study catchments are characterized in terms of several geomorphologic and climatic descriptors. The objective of our study is threefold: (1) to inspect climatic and scale controls on flood frequency regime; (2) to verify the possible presence of changes in flood frequency regime by looking at changes in time of regional L-moments of annual maximum floods; (3) to develop an updated reference procedure for design flood estimation in Triveneto by using a focused-pooling approach (i.e. Region of Influence, RoI). Our study leads to the following conclusions: (1) climatic and scale controls on flood frequency regime in Triveneto are similar to the controls that were recently found in Europe; (2) a single year characterized by extreme floods can have a remarkable influence on regional flood frequency models and analyses for detecting possible changes in flood frequency regime; (3) no significant change was detected in the flood frequency regime, yet an update of the existing reference procedure for design flood estimation is highly recommended and we propose the RoI approach for properly representing climate and scale controls on flood frequency in Triveneto, which cannot be regarded as a single
Deng, Lujuan; Xie, Songhe; Cui, Jiantao; Liu, Tao
It is the essential goal of intelligent greenhouse environment optimal control to enhance income of cropper and energy save. There were some characteristics such as uncertainty, imprecision, nonlinear, strong coupling, bigger inertia and different time scale in greenhouse environment control system. So greenhouse environment optimal control was not easy and especially model-based optimal control method was more difficult. So the optimal control problem of plant environment in intelligent greenhouse was researched. Hierarchical greenhouse environment control system was constructed. In the first level data measuring was carried out and executive machine was controlled. Optimal setting points of climate controlled variable in greenhouse was calculated and chosen in the second level. Market analysis and planning were completed in third level. The problem of the optimal setting point was discussed in this paper. Firstly the model of plant canopy photosynthesis responses and the model of greenhouse climate model were constructed. Afterwards according to experience of the planting expert, in daytime the optimal goals were decided according to the most maximal photosynthesis rate principle. In nighttime on plant better growth conditions the optimal goals were decided by energy saving principle. Whereafter environment optimal control setting points were computed by GA. Compared the optimal result and recording data in real system, the method is reasonable and can achieve energy saving and the maximal photosynthesis rate in intelligent greenhouse
Nola, F. J. (Inventor)
A power factor controller for an ac induction motor is provided which is of the type comprising thyristor switches connected in series with the motor, phase detectors for sensing the motor current and voltage and providing an output proportional to the phase difference between the motor voltage and current, and a control circuit, responsive to the output of the phase detector and to a power factor command signal, for controlling switching of the thyristor. The invention involves sensing the induced emf produced by the motor during the time interval when the thyristor is off and for producing a corresponding feedback signal for controlling switching of the thyristor. The sensed emf is also used to enhance soft starting of the motor.
Liu, Xinsheng; Nie, Yuqin; Luo, Tianxiang; Yu, Jiehui; Shen, Wei; Zhang, Lin
Alpine and northern treelines are primarily controlled by low temperatures. However, little is known about the impact of low soil temperature on tree transpiration at treelines. We aim to test the hypothesis that in cold-limited forests, the main limiting factors for tree transpiration switch from low soil temperature before summer solstice to atmospheric evaporative demand after summer solstice, which generally results in low transpiration in the early growing season. Sap flow, meteorological factors and predawn needle water potential were continuously monitored throughout one growing season across Smith fir (Abies georgei var. smithii) and juniper (Juniperus saltuaria) treelines in southeast Tibet. Sap flow started in early May and corresponded to a threshold mean air-temperature of 0°C. Across tree species, transpiration was mainly limited by low soil temperature prior to the summer solstice but by vapor pressure deficit and solar radiation post-summer solstice, which was further confirmed on a daily scale. As a result, tree transpiration for both tree species was significantly reduced in the pre-summer solstice period as compared to post-summer solstice, resulting in a lower predawn needle water potential for Smith fir trees in the early growing season. Our data supported the hypothesis, suggesting that tree transpiration mainly responds to soil temperature variations in the early growing season. The results are important for understanding the hydrological response of cold-limited forest ecosystems to climate change.
Full Text Available The atmospheric pollution and de-pollution phenomena are influenced by a series of factors, among which, the most important are: the characteristics of the emission, the meteorological factors, the geographical factors and the anthropic factors. The meteorological factors influence the transport, depositing, dispersion or stagnation of the pollutants. In time, under the influence of the physical and chemical factors specific to the atmosphere, or through reactions with other pollutants, a pollutant usually changes its chemical nature. Among the meteorological factors with influence on the pollution, in the present paper we will analyze the precipitation and the wind. The air currents, especially the horizontal ones, are considered among the most important dispersion factors. The aim of the present paper is that of proposing a simple and efficient way of interpreting the role of wind and atmospheric precipitations in the atmospheric pollution and depollution. All the examples (for the predominant wind direction, for atmospheric calmness, for different precipitation characteristics and for different characteristics of the emission sources were given for the territory of Piatra Neamţ municipality. The municipality of Piatra Neamţ is situated at the emergence of the Bistriţa River from the mountain area, and it stretches out over 16 km from west to east and 8 km from north to south, with altitudes between 290 and 851 m. The western part is situated on the mountain corridor of the Bistriţa and the eastern part, in the Cracău – Bistriţa Depression. The main polluting sources are the chemical platform situated in the central-southern part of the proper urban area. Our research took was done in the period 1983 – 2003, by means of 15 stations for collecting the pollutants, and a meteorological network with continuous recording of the main climatic parameters, as well as a meteorological station. These were placed in very representative places
Xu, Baoji; Xie, Xiangyang
Energy balance - that is, the relationship between energy intake and energy expenditure - is regulated by a complex interplay of hormones, brain circuits and peripheral tissues. Leptin is an adipocyte-derived cytokine that suppresses appetite and increases energy expenditure. Ironically, obese individuals have high levels of plasma leptin and are resistant to leptin treatment. Neurotrophic factors, particularly ciliary neurotrophic factor (CNTF) and brain-derived neurotrophic factor (BDNF), are also important for the control of body weight. CNTF can overcome leptin resistance in order to reduce body weight, although CNTF and leptin activate similar signalling cascades. Mutations in the gene encoding BDNF lead to insatiable appetite and severe obesity. PMID:27052383
Booth, M.; Beral, V; SMITH, P.
A hospital-based case-control study of ovarian cancer was conducted in London and Oxford between October 1978 and February 1983. Menstrual characteristics, reproductive and contraceptive history and history of exposure to various environmental factors were compared between 235 women with histologically diagnosed epithelial ovarian cancer and 451 controls. High gravidity, hysterectomy, female sterilisation and oral contraceptive use were associated with a reduced risk of ovarian cancer. Infert...
Full Text Available Abstract Background Diabetes mellitus type II afflicts at least 2 million people in Iran. Neuropathy is one of the most common complications of diabetes and lowers the patient's quality of life. Since neuropathy often leads to ulceration and amputation, we have tried to elucidate the factors that can affect its progression. Methods In this case-control study, 110 diabetic patients were selected from the Shariati Hospital diabetes clinic. Michigan Neuropathic Diabetic Scoring (MNDS was used to differentiate cases from controls. The diagnosis of neuropathy was confirmed by nerve conduction studies (nerve conduction velocity and electromyography. The multiple factors compared between the two groups included consumption of angiotensin converting enzyme inhibitors (ACEI, blood pressure, serum lipid level, sex, smoking, method of diabetes control and its quality. Results Statistically significant relationships were found between neuropathy and age, gender, quality of diabetes control and duration of disease (P values in the order: 0.04, 0.04, Conclusion In this study, hyperglycemia was the only modifiable risk factor for diabetic neuropathy. Glycemic control reduces the incidence of neuropathy, slows its progression and improves the diabetic patient's quality of life. More attention must be paid to elderly male diabetic patients with poor diabetes control with regard to regular foot examinations and more practical education.
Kibue, Grace Wanjiru; Liu, Xiaoyu; Zheng, Jufeng; zhang, Xuhui; Pan, Genxing; Li, Lianqing; Han, Xiaojun
Impacts of climate variability and climate change are on the rise in China posing great threat to agriculture and rural livelihoods. Consequently, China is undertaking research to find solutions of confronting climate change and variability. However, most studies of climate change and variability in China largely fail to address farmers' perceptions of climate variability and adaptation. Yet, without an understanding of farmers' perceptions, strategies are unlikely to be effective. We conducted questionnaire surveys of farmers in two farming regions, Yifeng, Jiangsu and Qinxi, Anhui achieving 280 and 293 responses, respectively. Additionally, we used climatological data to corroborate the farmers' perceptions of climate variability. We found that farmers' were aware of climate variability such that were consistent with climate records. However, perceived impacts of climate variability differed between the two regions and were influenced by farmers' characteristics. In addition, the vast majorities of farmers were yet to make adjustments in their farming practices as a result of numerous challenges. These challenges included socioeconomic and socio-cultural barriers. Results of logit modeling showed that farmers are more likely to adapt to climate variability if contact with extension services, frequency of seeking information, household heads' education, and climate variability perceptions are improved. These results suggest the need for policy makers to understand farmers' perceptions of climate variability and change in order to formulate policies that foster adaptation, and ultimately protect China's agricultural assets.
XU Sihuang; W.Lynn Watney
In marine strata from Sinian to Middle Triassic in South China,there develop four sets of regional and six sets of local source rocks,and ten sets of reservoir rocks.The occurrence of four main formation periods in association with five main reconstruction periods,results in a secondary origin for the most marine gas pools in South China.To improve the understanding of marine gas pools in South China with severely deformed geological background,the dominant control factors are discussed in this paper.The fluid sources,including the gas cracked from crude oil,the gas dissolved in water,the gas of inorganic origin,hydrocarbons generated during the second phase,and the mixed pool fluid source,were the most significant control factors of the types and the development stage of pools.The period of the pool formation and the reconstruction controlled the pool evolution and the distribution on a regional scale.Owing to the multiple periods of the pool formation and the reconstruction,the distribution of marine gas pools was complex both in space and in time,and the gas in the pools is heterogeneous.Pool elements,such as preservation conditions,traps and migration paths,and reservoir rocks and facies,also served as important control factors to marine gas pools in South China.Especially,the preservation conditions played a key role in maintaining marine oil and gas accumulations on a regional or local scale.According to several dominant control factors of a pool,the pool-controlling model can be constructed.As an example,the pool-controlling model of Sinian gas pool in Weiyuan gas field in Sichuan basin was summed up.
Xu, S.; Watney, W.L.
In marine strata from Sinian to Middle Triassic in South China, there develop four sets of regional and six sets of local source rocks, and ten sets of reservoir rocks. The occurrence of four main formation periods in association with five main reconstruction periods, results in a secondary origin for the most marine gas pools in South China. To improve the understanding of marine gas pools in South China with severely deformed geological background, the dominant control factors are discussed in this paper. The fluid sources, including the gas cracked from crude oil, the gas dissolved in water, the gas of inorganic origin, hydrocarbons generated during the second phase, and the mixed pool fluid source, were the most significant control factors of the types and the development stage of pools. The period of the pool formation and the reconstruction controlled the pool evolution and the distribution on a regional scale. Owing to the multiple periods of the pool formation and the reconstruction, the distribution of marine gas pools was complex both in space and in time, and the gas in the pools is heterogeneous. Pool elements, such as preservation conditions, traps and migration paths, and reservoir rocks and facies, also served as important control factors to marine gas pools in South China. Especially, the preservation conditions played a key role in maintaining marine oil and gas accumulations on a regional or local scale. According to several dominant control factors of a pool, the pool-controlling model can be constructed. As an example, the pool-controlling model of Sinian gas pool in Weiyuan gas field in Sichuan basin was summed up. ?? Higher Education Press and Springer-Verlag 2007.
Full Text Available Climatic factors, especially temperature and precipitations, greatly affect the dynamics of the hare number and population. Climatic factors directly affect the physiological and reproductive processes of both individuals and entire populations, or indirectly, through the availability of food, competition with other species, predators and other. The age structure of the hare population at the end of the period of reproduction is an important indicator of the population growth that is used for planning the level of explotation of the hare population (hunting. The rational use of the hare's population is one of the most important protection procedures and it should be well monitored and controlled by the hunting professionals. We used the average monthly temperature and the sum of monthly precipitations in the hare reproductive period (March-September during ten years (2000 - 2009, together with the percent of young in the hare population, on the territory of Bačka, for multiple regression (stepwise analysis. Results of the regression analysis show an association between the percentage of young hares and the influence of climatic factors. The average temperature and sum of precipitation in June, are the strongest predictor of the percent of young in the hare’s population in Bačka. According to the coefficient of determination (R2=0.50 climatic parameters account for 50% of variance in the percentage of young hares in Bačka. The regression correlation coefficient of all factors was R=0.70, which is on the border line between medium and high correlation.
Many experiments were undertaken to study the responses of the lentil cultivars 'Large blonde' and 'Anicia' to controlled environmental factors. They covered different aspects of the physiology and the ecology of the crop.The orientation experiments (2) involved germination and depth of sowing. The
The atmospheric corrosion of marble was evaluated in terms of SO2 concentration as air pollution and climatic factors such as rainfall, relative humidity, temperature and so on under the field exposure. Marble of calcite type (CaCO3) was exposed to outdoor atmospheric environment with and without a rain shelter at four test sites in the southern part of Vietnam for 3-month, 1- and 2-year periods from July 2001 to September 2003. The thickness loss of marble was investigated gravimetrically. X-ray diffraction and X-ray fluorescent methods were applied to study corrosion products on marble. The corrosion product of marble was only gypsum (CaSO4 . 2H2O) and was washed out by rain under the unsheltered exposure condition. It was found that the most substantial factors influencing the corrosion of marble were rainfall, SO2 concentration in the air and relative humidity. Based on the results obtained, we estimated the dose-response functions for the atmospheric corrosion of marble in the southern part of Vietnam
Dehlendorff, Christian; Kulahci, Murat; Andersen, Klaus Kaae
In this study we propose a new method for designing computer experiments inspired by the split plot designs used in physical experimentation. The basic layout is that each set of controllable factor settings corresponds to a whole plot for which a number of subplots, each corresponding to one...... should be guaranteed. Our proposed method allows for a large number of uncontrollable and controllable settings to be run in a limited number of runs while uniformly covering the design space for the uncontrollable factors....... combination of settings of the uncontrollable factors, is employed. The caveat is a desire that the subplots within each whole plot cover the design space uniformly. A further desire is that in the combined design, where all experimental runs are considered at once, the uniformity of the design space coverage...
Wang, G.; Ahmed, K. F.; You, L.
Land use changes constitute an important regional climate change forcing in West Africa, a region of strong land-atmosphere coupling. At the same time, climate change can be an important driver for land use, although its importance relative to the impact of socio-economic factors may vary significant from region to region. This study compares the contributions of climate change and socioeconomic development to potential future changes of agricultural land use in West Africa and examines various sources of uncertainty using a land use projection model (LandPro) that accounts for the impact of socioeconomic drivers on the demand side and the impact of climate-induced crop yield changes on the supply side. Future crop yield changes were simulated by a process-based crop model driven with future climate projections from a regional climate model, and future changes of food demand is projected using a model for policy analysis of agricultural commodities and trade. The impact of human decision-making on land use was explicitly considered through multiple "what-if" scenarios to examine the range of uncertainties in projecting future land use. Without agricultural intensification, the climate-induced decrease of crop yield together with increase of food demand are found to cause a significant increase in agricultural land use at the expense of forest and grassland by the mid-century, and the resulting land use land cover changes are found to feed back to the regional climate in a way that exacerbates the negative impact of climate on crop yield. Analysis of results from multiple decision-making scenarios suggests that human adaptation characterized by science-informed decision making to minimize land use could be very effective in many parts of the region.
Full text: Full text: Large-scale civil engineering works are often designed with reference to the probable maximum precipitation (PMP) design flood, in which one required input is the PMP estimate for a particular catchment. The PMP is the greatest depth of precipitation meteorologically possible for a given duration, area, location and time of year, with no allowance made for long-term climatic trends. PMP estimates are derived for any catchment in Australia using an appropriate generalised method. Each method relies on a catalogue of previous significant rainfall events of various areas and durations for a particular application zone. The PMP rainfall depth is derived from the upper bound of the maximised-standardised convergence rainfall, in which the available moisture for each event has been maximised to its climatological extreme and all events standardised to a common location. The event associated with the PMP rainfall depth (for a particular area and duration) is also assumed to operate at an optimal efficiency. The PMP estimates, although assumed to be independent of climate change, are likely to be influenced by changes in factors contributing to moisture availability (through both storm and extreme precipitable water) and relative storm efficiency (the ratio of rainfall rate to storm precipitable water). Analyses indicate that changes in extreme precipitable water will have the most direct impact on PMP estimates when applied to a particular catchment. The CSIRO Mk3.0 climate model was used to assess for changes in the 90th percentile of precipitable water for different emission scenarios up to the year 2100. These changes indicate that extreme precipitable water will increase for most seasons and locations across Australia that have been associated with previous significant rainfall events. However when assessing the effect of changes, an additional complication results from the transposition process within the generalised methods. There is a
Wilson, Adam M; Latimer, Andrew M; Silander, John A
Conservation of biodiversity and natural resources in a changing climate requires understanding what controls ecosystem resilience to disturbance. This understanding is especially important in the fire-prone Mediterranean systems of the world. The fire frequency in these systems is sensitive to climate, and recent climate change has resulted in more frequent fires over the last few decades. However, the sensitivity of postfire recovery and biomass/fuel load accumulation to climate is less well understood than fire frequency despite its importance in driving the fire regime. In this study, we develop a hierarchical statistical framework to model postfire ecosystem recovery using satellite-derived observations of vegetation as a function of stand age, topography, and climate. In the Cape Floristic Region (CFR) of South Africa, a fire-prone biodiversity hotspot, we found strong postfire recovery gradients associated with climate resulting in faster recovery in regions with higher soil fertility, minimum July (winter) temperature, and mean January (summer) precipitation. Projections using an ensemble of 11 downscaled Coupled Model Intercomparison Project Phase 5 (CMIP5) general circulation models (GCMs) suggest that warmer winter temperatures in 2080-2100 will encourage faster postfire recovery across the region, which could further increase fire frequency due to faster fuel accumulation. However, some models project decreasing precipitation in the western CFR, which would slow recovery rates there, likely reducing fire frequency through lack of fuel and potentially driving local biome shifts from fynbos shrubland to nonburning semidesert vegetation. This simple yet powerful approach to making inferences from large, remotely sensed datasets has potential for wide application to modeling ecosystem resilience in disturbance-prone ecosystems globally. PMID:26150521
Tierney, Jessica E.; Russell, James M.; Huang, Yongsong; Damsté, Jaap S. Sinninghe; Hopmans, Ellen C.; Cohen, Andrew S.
The processes that control climate in the tropics are poorly understood. We applied compound-specific hydrogen isotopes (δD) and the TEX86 (tetraether index of 86 carbon atoms) temperature proxy to sediment cores from Lake Tanganyika to independently reconstruct precipitation and temperature variations during the past 60,000 years. Tanganyika temperatures follow Northern Hemisphere insolation and indicate that warming in tropical southeast Africa during the last glacial termination began to increase ~3000 years before atmospheric carbon dioxide concentrations. δD data show that this region experienced abrupt changes in hydrology coeval with orbital and millennial-scale events recorded in Northern Hemisphere monsoonal climate records. This implies that precipitation in tropical southeast Africa is more strongly controlled by changes in Indian Ocean sea surface temperatures and the winter Indian monsoon than by migration of the Intertropical Convergence Zone.
Asner, Gregory P; Knapp, David E; Anderson, Christopher B; Martin, Roberta E; Vaughn, Nicholas
Leaf economics spectrum (LES) theory suggests a universal trade-off between resource acquisition and storage strategies in plants, expressed in relationships between foliar nitrogen (N) and phosphorus (P), leaf mass per area (LMA), and photosynthesis. However, how environmental conditions mediate LES trait interrelationships, particularly at large biospheric scales, remains unknown because of a lack of spatially explicit data, which ultimately limits our understanding of ecosystem processes, such as primary productivity and biogeochemical cycles. We used airborne imaging spectroscopy and geospatial modeling to generate, to our knowledge, the first biospheric maps of LES traits, here centered on 76 million ha of Andean and Amazonian forest, to assess climatic and geophysical determinants of LES traits and their interrelationships. Elevation and substrate were codominant drivers of leaf trait distributions. Multiple additional climatic and geophysical factors were secondary determinants of plant traits. Anticorrelations between N and LMA followed general LES theory, but topo-edaphic conditions strongly mediated and, at times, eliminated this classic relationship. We found no evidence for simple P-LMA or N-P trade-offs in forest canopies; rather, we mapped a continuum of N-P-LMA interactions that are sensitive to elevation and temperature. Our results reveal nested climatic and geophysical filtering of LES traits and their interrelationships, with important implications for predictions of forest productivity and acclimation to rapid climate change. PMID:27354534
R. J. Hilton; A. Galy; Niels Hovius; S. J. Kao; Horng, M.J.; Chen, H.;
 Erosion of particulate organic carbon (POC) occurs at very high rates in mountain river catchments, yet the proportion derived recently from atmospheric CO2 in the terrestrial biosphere (POCnon-fossil) remains poorly constrained. Here we examine the transport of POCnon-fossil in mountain rivers of Taiwan and its climatic and geomorphic controls. In 11 catchments we have combined previous geochemical quantification of POC source (accounting for fossil POC from bedrock), with measurements o...
Range reduction caused by climate control is a barrier to widespread adoption of electric vehicles (EV). Higher efficiency and lower energy consumption by the air conditioning system will mitigate this disadvantage, as power consumption inside electric vehicles is a very relevant issue. Moreover, several European Union directives prohibit the use of HFC 134a or any other fluorinated greenhouse gas with a Global Warming Potential (GWP) higher than 150 in new mobile air conditioning systems ...
Negotiated over 60 years ago and ratified in 1964, the Columbia River Treaty (CRT or "the Treaty"), is often looked to as the standard for cross-jurisdictional water management. A crucial aspect of the Treaty is the governance of water flows to minimize downstream flooding. Climate change directly impacts the hydrology of the Columbia River, which has implications for activities such as power generation and flood control management. The Treaty needs to be modernized to incorporate the effe...
H. A. Biswas
Full Text Available One of the most hot issues in the recent environmental research worldwide has become the harmful effects of climate change on the ecosystems and environment due to global warming. Bangladesh is one of the most vulnerable countries not only in the South East Asia but also in the world. It is predicted that a large portion of the South-western region of Bangladesh will go under sea in the next 50 to 100 years due to sea level rise. In this paper, we first discuss some potential impacts of climate change in Bangladesh and its aftermath on the ecosystems and secondly, we study a mathematical model of climate change in terms of ordinary differential equations (ODEs and apply optimal control techniques in the form of Pontryagin Maximum Principle (PMP to investigate the control strategy of greenhouse gases (GHGs. We study the model numerically using some known nonlinear ‘optimal control solvers’ and the results are illustrated with numerical simulations.
Goldammer, Lori; Swahn, Monica; Strasser, Sheryl; Ashby, Jeffrey; Meyers, Joel
Introduction: Research dedicated to identification of precursors to cases of aggravated bullying in schools has led to enhanced knowledge of risk factors for both victimization and perpetration. However, characteristics among those who are more likely to intervene in such situations are less understood. The purpose of this study is to examine the associations between demographic characteristics, school climate and psychosocial factors, and willingness to intervene in a bullying situation amon...