Increase In Average Temperature Research Articles

Impact of climate change on the long-term water balance in the Yarlung Zangbo basin

The Himalayan and Tibetan Plateau (TP) region serves as the “Asian water tower”. Yarlung Zangbo basin (YZB) is one of most important major rivers originating from TP sustaining billions of lives in the downstream alluvial plain. Climate change has impacted the hydrological cycle in this alpine region; however, the temporal and spatial trends of runoff and the water balance has not been quantified adequately. Here, we have optimized the snowmelt module of the Soil and Water Assessment Tool (SWAT) for the YZB to quantify the historical and future variability in the runoff, snowmelt water, and water balance components. According to the results of the Coupled Model Intercomparison Project Five and Six (CMIP5 and CMIP6) the future precipitation (2020–2099) projected by the CMIP6 will increase by 2.7% when compared to historical reference (1980–2019), while the precipitation will increase by 10.2% when projected by the CMIP5. The increase in average air temperature (2.4°C) projected by CMIP6 exceeds that of CMIP5 (1.9°C). The runoff between 2020 and 2050 will decrease by −12.7% compared with historical reference, and it will further decline by −9.2% during 2060 and 2099. Based on the average results of CMIP5 and CMIP6, the water balance deficit will increase primarily due to an increase in evaporation of 42.4%, whereas snowmelt (−32.1%), water yield (−9.4%), soil water (−19.8%), and groundwater recharge (−17.8%) will decrease. Long-term water balance evaluation implicates that middle and upper reaches will face a higher risk of drought, implying a potential threat to the sustainability of grassland ecosystems upstream.

ПРІОРИТЕТИ У ВИКОРИСТАННІ ВИКОПНИХ ВИДІВ ПАЛИВА ТА УТРИМАННІ ЖИТЛОВОГО ФОНДУ

The trends of global temperature increase in the world due to excessive burning of fossil hydrocarbons are given. Excessive extraction and burning of fossil fuels (hard coal, petroleum products, natural gas) have led to an increase in their cost and climate change. About 40% of CO2 emissions today come from burning coal, 33% from oil refining products, and 22% from natural gas. An increase in CO2 content in the atmosphere leads to a drop in the Earth's surface temperature. At the global level, the world community has adopted three main international agreements on climate change: the UN Framework Convention on Climate Change (1992); Kyoto Protocol (1997); Paris Agreement (2015). More than 190 countries have signed the Paris Agreement. Its main goals are to achieve carbon neutrality by 2050 and to keep the increase in the global average temperature below 2°C by 2100, preferably to 1.5°C.
 The construction industry is responsible for consumption of up to 40% of all energy. which are used in economies countries of the world In the summarized reports of experts at the 27th UN Conference on Climate Change (COP27), which took place in 2022 year in Egypt (Sharm el-Sheikh) it was stated that in 2022 1% more CO2 will be released into the atmosphere than in in 2021. The main volumes of greenhouse gas emissions come from the burning of fossil fuels. Brought comparative analysis of CO2 emissions when burning different types of fuel.
 The dynamics of the production of fossil fuels - hard coal, oil and natural gas - is studied, which indicates a significant decrease in their production and consumption. Modern approaches to the growth of RES volumes are considered, the dynamics of the growth of SPP capacities are given. On the basis of European experience, the prospects for the installation of balcony mini SPPs are shown.
 Individual heating systems and decentralization of engineering systems for providing housing help to increase their stability in adverse conditions. The organizational features of the transfer of the housing stock from a centralized heating system to individual electric and gas heating are revealed. Based on the analysis of the European experience of maintaining the housing stock, the main directions for reducing energy consumption and greenhouse gas emissions of the existing housing stock are given.

Green Conversion of Carbon Dioxide and Sustainable Fuel Synthesis

Carbon capture and use may provide motivation for the global problem of mitigating global warming from substantial industrial emitters. Captured CO2 may be transformed into a range of products such as methanol as renewable energy sources. Polymers, cement, and heterogeneous catalysts for varying chemical synthesis are examples of commercial goods. Because some of these components may be converted into power, CO2 is a feedstock and excellent energy transporter. By employing collected CO2 from the atmosphere as the primary hydrocarbon source, a carbon-neutral fuel may be created. The fuel is subsequently burned, and CO2 is released into the atmosphere like a byproduct of the combustion process. There is no net carbon dioxide emitted or withdrawn from the environment during this process, hence the name carbon-neutral fuel. In a world with net-zero CO2 emissions, the anthroposphere will have attained its carbon hold-up capacity in response to a particular global average temperature increase, such as 1.5 °C. As a result, each carbon atom removed from the subsurface (lithosphere) must be returned to it, or it will be expelled into the atmosphere. CO2 removal technologies, such as biofuels with carbon sequestration and direct air capture, will be required to lower the high CO2 concentration in the atmosphere if the Paris Agreement’s ambitious climate targets are to be realized. In a carbon-neutral scenario, CO2 consumption with renewable energy is expected to contribute to the displacement of fossil fuels. This article includes a conceptual study and an evaluation of fuel technology that enables a carbon-neutral chemical industry in a net-zero-CO2-emissions environment. These are based on the use of collected CO2 as a feedstock in novel chemical processes, along with “green” hydrogen, or on the use of biomass. It will also shed light on innovative methods of green transformation and getting sustainable, environmentally friendly energy.

Оценка будущих температур воздуха Центральной Африки по сценариям проектов CMIP5 и CMIP6

Based on the results of the historical experiment of the CMIP5 and CMIP6 projects, the effectiveness of the scenario estimates (RCP/SSP1 2.6, RCP/SSP2 4.5 and RCP/SSP5 8.5) of the future air temperature for Central Africa for the IPSL and BCC global climate models is evaluated and the simulation results of these projects are compared with each other and with the observations of meteorological stations in the region, both for the historical experimental period and with the observations of recent years for the implementation of future climate projections. Based on historical experiment and future evaluations over the past 16 years, it has been determined that the CMIP6 project model versions are no more effective than the CMIP5 results when compared with observational data. Due to the fact that the differences between observational and modeling data are systematic, the results of scenario estimates were adjusted according to the principle of similarity of temperature growth rates for the historical observation period and the future scenario period untilthe end ofthe 21stcentury,which is divided into 3 intervalsfor estimating average values: 2011–2040, 2041–2070 and 2071–2100. Future air temperatures in Central Africawere estimated both forthe average values fortheterritory and forthetemperatures of individualweatherstations based on the adjusted scenario values, which differed in CMIP5 and CMIP6 by no more than 0.1°С. It was found that the average temperature increase over the territory in all months by the end of the 21st century reaches 2.0–2.3°C, and according to estimates at individual weather stations, spatial distributions of future temperatures were obtained, which show the greatest increase in the north of the region near the Sahel.

Climate change effect on water temperature and evaporation in Lake Qarun

ABSTRACT Climate change can have significant effects on the water and heat budgets of lakes and reservoirs. This study examined the effect of climate change on Lake Qarun through analyzing the temporal variation in lake surface temperature and evaporation from the lake. The analysis was based on the remote-sensing dataset MOD11A1 and the ERA5 climate reanalysis dataset. Daily surface temperatures for 1-km MOD11A1 pixels were filtered to remove outliers, averaged to obtain mean lake temperature, and then aggregated to compute the monthly average lake temperature. Lake evaporation was estimated by applying an un-mixing algorithm to ERA5 evaporation fluxes for mixed land-lake pixels and land-only pixels. The resulting monthly evaporation from the lake was corrected using a regression model based on evaporation estimates available in the literature for Lake Qarun. The regression model performance was confirmed through the Nash–Sutcliffe efficiency coefficient, correlation coefficient, and root mean square error. Over the period 1980 to 2019, findings show that annual evaporation ranged between 140 and 190 cm/year. Maximum average monthly evaporation for the study period is 21 cm in July while the minimum is 6.7 cm in February from 1980 to 2019. For the average lake surface temperature, it varied between ~31.9 and 33.9°C over the period 2000 to 2019. For the same time period, average maximum and minimum monthly temperatures were 44°C in August and 20.1°C in January. It is concluded that the average increase in evaporation and lake surface temperature is 37 mm/decade and 0.4°C/decade, respectively. The increase in both lake surface temperature and evaporation is likely due to climate change effects. However, using datasets with a larger temporal record for lake surface temperature, further studies can be applied for confirmation. Also, further confirmation can be obtained by applying the same analysis to other lakes in Egypt.

The Role of Crop Management Practices and Adaptation Options to Minimize the Impact of Climate Change on Maize (Zea mays L.) Production for Ethiopia

Climate change impact assessment along with adaptation measures are key for reducing the impact of climate change on crop production. The impact of current and future climate change on maize production was investigated, and the adaptation role of shifting planting dates, different levels of nitrogen fertilizer rates, and choice of maize cultivar as possible climate change adaptation strategies were assessed. The study was conducted in three environmentally contrasting sites in Ethiopia, namely: Ambo, Bako, and Melkassa. Future climate data were obtained from seven general circulation models (GCMs), namely: CanESM2, CNRM-CM5, CSIRO-MK3-6-0, EC-EARTH, HadGEM2-ES, IPSL-CM5A-MR, and MIROC5 for the highest representative concentration pathway (RCP 8.5). GCMs were bias-corrected at site level using a quantile-quantile mapping method. APSIM, AquaCrop, and DSSAT crop models were used to simulate the baseline (1995–2017) and 2030s (2021–2050) maize yields. The result indicated that the average monthly maximum air temperature in the 2030s could increase by 0.3–1.7 °C, 0.7–2.2 °C, and 0.8–1.8 °C in Ambo, Bako, and Melkassa, respectively. For the same sites, the projected increase in average monthly minimum air temperature was 0.6–1.7 °C, 0.8–2.3 °C, and 0.6–2.7 °C in that order. While monthly total precipitation for the Kiremt season (June to September) is projected to increase by up to 55% (365 mm) for Ambo and 75% (241 mm) for Bako respectively, whereas a significant decrease in monthly total precipitation is projected for Melkassa by 2030. Climate change would reduce maize yield by an average of 4% and 16% for Ambo and Melkassa respectively, while it would increase by 2% for Bako in 2030 if current maize cultivars were grown with the same crop management practice as the baseline under the future climate. At higher altitudes, early planting of maize cultivars between 15 May and 1 June would result in improved relative yields in the future climate. Fertilizer levels increment between 23 and 150 kg ha−1 would result in progressive improvement of yields for all maize cultivars when combined with early planting for Ambo. For a mid-altitude, planting after 15 May has either no or negative effect on maize yield. Early planting combined with a nitrogen fertilizer level of 23–100 kg ha−1 provided higher relative yields under the future climate. Delayed planting has a negative influence on maize production for Bako under the future climate. For lower altitudes, late planting would have lower relative yields compared to early planting. Higher fertilizer levels (100–150 kg ha−1) would reduce yield reductions under the future climate, but this varied among maize cultivars studied. Generally, the future climate is expected to have a negative impact on maize yield and changes in crop management practices can alleviate the impacts on yield.

ASSESSMENT OF THERMAL AND NATURAL MOISTURE PROVISION IN TERRITORY OF TURKESTAN REGION OF THE REPUBLIC OF KAZAKHSTAN IN CHANGING CLIMATE CONDITIONS

The assessment of natural moisture availability of the natural areas of the Turkestan region of the Republic of Kazakhstan for 1941-2020 (by providing a comparative analysis of indicators for 1941-1960 and 2001-2020) was conducted based on the use of the natural moisture coefficient and hydrothermal index or "dryness index" predicated on energy resources (total of biologically active air temperatures above 10 °С, photosynthetically active radiation, evaporating capacity and water consumption of agricultural land). The results of a comparative analysis of climatic indices changes in the natural areas of the Turkestan region for 1941 to 2020 have shown that there is an increase in average annual air temperatures in all natural areas, and the annual precipitation tends downward which affects the formation of energy resources and natural water supply. The identified features of changes in the natural moisture coefficient and hydrothermal index or "dryness index" in natural area of Turkestan region, make it possible to adjust the spread of its boundaries and consider these changes in the territorial organization of agricultural nature management.

Is Aquatic Fern <i>Salvinia natans</i> (Salviniaceae) Rare in Russia?

According to publication and literature, herbarium data, materials of Internet resources, the change in distribution of aquatic fern Salvinia natans (Salviniaceae) on Russian territory was traced since the beginning of XX century until 2021, and the current boundaries of its range were determined. Among the bioclimatic and temperature indicators that determine the distribution of S. natans, the minimum and maximum temperatures in October and January and the maximum temperatures in April and July showed the highest statistical significance, which is associated with important stages of the life cycle of S. natans. Comparison of species localities with climatic and temperature indicators for the time periods of 1960–1969, 2010–2018, 2011–2021 showed that up to 2021 in the European part, West Siberia, and the Far East there was significant spreading of S. natans to the north (more than 200 km). A notable increase in the number of records of the species has been found since the 2000s in different regions. For example, in the Ivanovo Region from 2018 to 2021 their number has increased more than three time. The expansion of the species occurs against the background of a noticeable increase in average annual temperatures and changes in other bioclimatic indicators. If present temperature trends continue, S. natans will expand its range even further north, east, and west in European Russia, north and west in West Siberia and the Far East. Due to the ongoing expansion of S. natans, the premises for the exclusion of the species from a number of regional Red Data Books were discussed.

Impact of Climate Change on Ruderal Communities in the Conditions of Ukraine

Abstract We elucidated the reaction of ruderal vegetation community to environmental changes. It made it possible to assess the level and nature of the synanthropic vegetation dynamics, fluctuation processes, and also to indicate the scenarios of evolution of ruderal communities throughout the environmental changes, in particular, climate changes. In this study, we used the original methods: synphytoindications and estimation of the climate change impact and the species reaction according to their ecological strategy. Dataset included 1200 phytosociological relevés of different synanthropic habitat types (borders of fields, ruderal areas, and railway tracks). As a result of vegetation analysis, we obtained 16 alliances of ruderal vegetation belonging to the six classes and two natural vegetation derivatives of the Sedo-Scleranthetea Br.-Bl. 1955 and Festuco-Brometea Br.-Bl. & Tx. 1943. Evaluation of ecological indicator value changes in relation to 1, 2 and 3 °C increase in average annual temperatures allowed to determine how significant is the threat to the existence of ruderal communities. It is particularly noticeable in the thermal regime, and some changes in edaphic properties of soil, especially acidity (pH). Under the conditions of climate changes and ecological indicator value changes, such communities could be easily restored both in the appropriate conditions of the region and outside it, that is, shifting their range. But thanks to this strategy, the emergence of new species and, as a result of this, the formation of completely new vegetation types is possible.

Camel livestock in the Algerian Sahara under the context of climate change: Milk properties and livestock production practices

Camel livestock is an ancestral activity in Algeria; however, climate change has forced camel herders to modify their breeding practices to make them more sustainable. This study summarized livestock production practices, milk qualities, and the potential of camel livestock to preserve production ability under global warming. To collect data related to livestock farming practices, 10 camel herders were interviewed using a formal questionnaire. Then, 15 milk samples (9 samples of raw milk and 6 samples that had undergone heat treatment) were collected in the region of Oued Souf in southeastern Algeria to carry out the physicochemical and bacteriological analysis. From 1990 to 2021, results showed severe drought accompanied by a significant increase in the annual average maximum temperature with a temporal slope of 0.04 °C year−1 and a significant decline in annual precipitation with a temporal slope of −0.07 mm year−1. A socio-demographic survey revealed a low educational level for camel herders. They owned small herd of camels (6.84 ± 8.66 camels) in the transhumant and extensive system or > 150 heads in the nomadic and extensive system. The average daily milk production in the nomadic system was very low (<3 L/day); it was less important compared to that in the transhumant system (4–5 L/day), with an acceptable physicochemical quality but poor bacteriological quality. Given the susceptibility of the research area, we recorded that camel livestock and travel mobility were used as adaptation strategies to the effects of climate change. On the one hand, camel breed conservation programs can enhance biodiversity and a sustainable ecosystem. On the other side, a genetic improvement program that might boost productivity and profitability might be advantageous. Smallholders may benefit from this by receiving a fair and secure income and good working conditions, which could contribute significantly to social equity and local economies.

Dynamical Modelling of the Global Cement Production and Supply System, Assessing Climate Impacts of Different Future Scenarios

The global cement and concrete demand, production, supply, and the general global market price was modelled using the WORLD7 model for different future scenarios. The model was used to analyze some possible measures to reduce the climate impact of cement production. The main result from this study is that three factors may bring regulatory limitations to be imposed on cement production. The contribution of CO2 to the atmosphere, the amount of iron used in construction and the use of energy in production are the main factors that may cause limitations. Cement accounts for about 8% of the global CO2 emissions and energy use at present, and this fraction is projected by the simulations to continue to increase. To reduce CO2 emissions from cement production, ending fossil fuel use for calcination, combined with a change towards using mortar as an alternative for making concrete should be considered. Our conclusion is that the long-term limitation for cement production is the availability of carbon-free energy, and the availability of iron for reinforcement bars. Eliminating the use of hydrocarbons for cement calcination may reduce the future the contribution from cement by 38%. Eliminating the use of hydrocarbons for calcination combined with substituting cement with mortar to 50%, the contribution to the future global average temperature increase is reduced by 62%. Eliminating the use of hydrocarbons for calcination combined with substituting cement with mortar to 90% is a reduction by 90% in the contribution from cement.

Historic climate change trends and impacts on crop yields in key agricultural areas of the prairie provinces in Canada: a literature review

The objective of this literature review was to compile research findings on climate change and its impacts on crop production in Prairie Provinces of Canada. Our search strategy included finding primary literature articles from various databases. Seven articles reported increases in average and minimum air temperature over time in the Prairie Provinces of Canada. Increases in maximum air temperature were smaller than that for minimum air temperature. Growing degree days and corn heat units also increased over time, which has allowed for potential expansion of corn growth northwards. While overall increases in average annual precipitation and growing season precipitation have occurred in Canada between 1900 and 2021, western Canada showed increases in some regions but decreases in others. Off-season precipitation and snow cover duration in Canada have decreased since 1950. The number of frost-free days has increased across Canada, on the Prairies and southern Saskatchewan since 1900. Annual snowfall has decreased since 1950 and across Canada the annual maximum snow depth has also decreased. Overall, studies focusing on the Prairie Provinces in Canada have shown accelerated changes in several climate parameters over time, affecting cropping areas and crop yields.

Research on creep and thermal stability of asphalt under outdoor aging (NEA) in Tibetan areas

In order to explore the aging performance attenuation mechanism of 90# and SBS (styrene–butadiene–styrene block copolymer) modified asphalt under the large temperature difference and strong ultraviolet radiation in the Tibetan area, this paper adopts the outdoor natural exposure aging (NEA) condition in the Tibetan area. Scanning calorimetry and thermogravimetric analysis techniques were used to test and analyse the permanent deformation resistance and thermal stability of two asphalts with different aging times (0 month (0M), April (4M) and 8 months (8M)) to study the on-site aging mechanism of asphalt in Tibetan areas. The results show that with the prolongation of NEA time, the non-recoverable creep compliance, polymer area and glass transition temperature of the two asphalts decrease, while the average recovery rate and deformation temperature increase, and the aging degree gradually deepens. Under the special outdoor conditions in Tibetan areas, the permanent deformation resistance and thermal stability of SBS modified asphalt are better than 90# asphalt. The research results explored the aging and decay mechanism of the two asphalts from the macro and micro perspectives, which provided theoretical support for the research and development of anti-aging technology in Tibetan areas and guaranteeing the road performance of asphalt pavement in the whole life cycle.

Changes in Meteorological Elements and Its Impacts on Yunnan Plateau Lakes

In this study, we analyzed the main climatic factors influencing nine plateau lakes in Yunnan Province over the past 40 years (from 1980 to 2019) based on trend and mutation analyses. The results revealed that the air temperatures of these plateau lakes have increased, with an annual average air temperature increase of 0.18 °C per decade, during this 40-year period. From 2000 to 2005, there was an abrupt change in the air temperature increase, the rate of which was 0.20 °C per decade, and there were reductions in long-wave radiation, relative humidity, wind speed, precipitation, and snowfall. In addition, the rising trend in the air temperature of these lakes located in northwest Yunnan (temperate climate, higher elevation) was found to be significantly higher than that of the lakes in central Yunnan (subtropical climate, lower elevation), whereas in contrast, the declining trends in long-wave radiation, relative humidity, wind speed, and precipitation were more pronounced in central than in northwestern Yunnan.

Investigating defects and annual degradation in UK solar PV installations through thermographic and electroluminescent surveys

As the adoption of renewable energy sources, particularly photovoltaic (PV) solar, has increased, the need for effective inspection and data analytics techniques to detect early-stage defects, faults, and malfunctions has become critical for maintaining the reliability and efficiency of PV systems. In this study, we analysed thermal defects in 3.3 million PV modules located in the UK. Our findings show that 36.5% of all PV modules had thermal defects, with 900,000 displaying single or multiple hotspots and ~250,000 exhibiting heated substrings. We also observed an average temperature increase of 21.7 °C in defective PV modules. Additionally, two PV assets with 19.25 and 8.59% thermal defects were examined for PV degradation, and results revealed a higher degradation rate when more defects are present. These results demonstrate the importance of implementing cost-effective inspection procedures and data analytics platforms to extend the lifetime and improve the performance of PV systems.

Evolution mechanism of temperature field of the frozen wall of the vertical shaft under cold energy extraction

ABSTRACT To verify the feasibility of extracting the excess cold energy of the frozen wall and clarify the variation mechanism of the frozen wall temperature field during the cold energy extraction process, this study carried out the field extraction experiment of the excess cold energy of the frozen wall in the central air shaft of Linhuan Coal Mine. The results showed that the maximum temperature difference of salt liquid before and after cold extraction was 19.9°C. The extraction effect of the frozen wall cold energy was very significant. Through numerical simulation, this study reproduced the whole process of cold energy extraction of the frozen wall, and find that on the 30th day of cold energy extraction, the average temperature increase of the frozen wall under the scheme of main row hole plus auxiliary hole cold energy extraction is 2.2 times that of only main row hole cold energy extraction. The main surface temperature of the frozen wall shows a “wavy” distribution, and the lowest point is in the central area of the frozen wall. The main surface temperature rises with the increase of cold energy extraction time. And on the 30th day of cold energy extraction, the temperature in the east, south, west, and north of the frozen wall increased by 5.8°C, 12.5°C, 8.5°C, 11.1°C, respectively. Meanwhile, it is found that the higher the salt temperature, the higher the thermal conductivity of the frozen wall, and the faster the average temperature increases.

Changing Climatic Conditions Affect Snow Cover in Annapurna Region of Nepal

Changing climatic conditions affecting the physical environment, hydrology, forest and wildlife, agriculture, and other sectors of the economy has become a major concern worldwide. The Annapurna Range in the Central Himalayas in Nepal is experiencing impacts of climate change on various fronts, including temperature increase and change in snow cover area (SCA). The objectives of this study were to assess spatio-temporal variation in temperature, precipitation, and SCA in the Annapurna massif and establish a relationship between these variables. This study analyzed the daily maximum and minimum temperature and precipitation records of six weather stations in the region, and performed a long-term analysis (1990–2020) of snow cover over Annapurna massif analysing Satellite images from the past three decades provided by satellite 5 through 8 of the Landsat program and Geographic Information System (GIS) technology. The SCA was determined through Landsat images using the Normalized Difference Snow Index (NDSI). Temperature analysis showed that the northeast (Chame) and northwest (Jomsom) parts of the massif were undergoing a consistent increase in average temperature at the rate of 0.07 and 0.03∘∘C per year, respectively. A north-south gradient was observed in total annual precipitation with total precipitation increasing in Ghandruk and Ranipauwa (Muktinath) at 50 mm and 4.8 mm per year, respectively, and decreasing in Manang Bhot at 4.7 mm per year. The precipitation events increased during spring in the west (Lete), northwest (Jomsom), and south (Ghandruk) of the massif, whereas it decreased in the north (Manang Bhot) and northeast (Chame) for all seasons. The SCA varied from 397 km22 to 1735 km22 with a significantly decreasing trend in December. There was a non-significant SCA increase during March, indicating that more snow coverage could appear in the spring in the future. These results could help local communities, government agencies, tourism industries, and other stakeholders develop resource management plans and climate change adaptation strategies.

Heat-related cardiorespiratory mortality: Effect modification by air pollution across 482 cities from 24 countries

BackgroundEvidence on the potential interactive effects of heat and ambient air pollution on cause-specific mortality is inconclusive and limited to selected locations. ObjectivesWe investigated the effects of heat on cardiovascular and respiratory mortality and its modification by air pollution during summer months (six consecutive hottest months) in 482 locations across 24 countries. MethodsLocation-specific daily death counts and exposure data (e.g., particulate matter with diameters ≤ 2.5 µm [PM2.5]) were obtained from 2000 to 2018. We used location-specific confounder-adjusted Quasi-Poisson regression with a tensor product between air temperature and the air pollutant. We extracted heat effects at low, medium, and high levels of pollutants, defined as the 5th, 50th, and 95th percentile of the location-specific pollutant concentrations. Country-specific and overall estimates were derived using a random-effects multilevel meta-analytical model. ResultsHeat was associated with increased cardiorespiratory mortality. Moreover, the heat effects were modified by elevated levels of all air pollutants in most locations, with stronger effects for respiratory than cardiovascular mortality. For example, the percent increase in respiratory mortality per increase in the 2-day average summer temperature from the 75th to the 99th percentile was 7.7% (95% Confidence Interval [CI] 7.6–7.7), 11.3% (95%CI 11.2–11.3), and 14.3% (95% CI 14.1–14.5) at low, medium, and high levels of PM2.5, respectively. Similarly, cardiovascular mortality increased by 1.6 (95%CI 1.5–1.6), 5.1 (95%CI 5.1–5.2), and 8.7 (95%CI 8.7–8.8) at low, medium, and high levels of O3, respectively. DiscussionWe observed considerable modification of the heat effects on cardiovascular and respiratory mortality by elevated levels of air pollutants. Therefore, mitigation measures following the new WHO Air Quality Guidelines are crucial to enhance better health and promote sustainable development.

Elevation-dependent warming of streams in mountainous regions: implications for temperature modeling and headwater climate refugia

Climate change is warming stream temperatures with significant implications for species that require cold temperatures to persist. These species often rely on headwater habitats in mountainous regions where elevation gradients in hydroclimatic conditions may induce differential patterns of long-term warming that affect the resistance of refugia. Forecasts from mechanistic and statistical stream temperature models diverge regarding whether this elevation dependence will cause above- or below-average warming in headwaters during warm summer periods, so we examined monitoring records for stream temperature (n = 271), air temperature (n = 690), and stream discharge (n = 131) across broad elevation gradients in a mountainous region of western North America to better understand potential future trends. Over a 40-year period characterized by rapid climate change from 1976–2015, air temperature stations exhibited below-average warming rates at high elevations while stream discharge declined at above average rates. Between climatically extreme years that involved summer air temperature increases >5 °C and discharge declines >70%, temperatures in high-elevation streams exhibited below average increases but otherwise showed negligible elevation dependence during intermediate climate years. In a subsequent example, it was demonstrated that elevation dependent stream warming has a minor effect on the amount of thermal habitat loss relative to the average water temperature increase within a mountain river network. We conclude that predictions of above average warming effects on headwater organisms for this region may be overly pessimistic and discuss reasons why different types of temperature models make divergent forecasts. Several research areas warrant greater attention, including descriptions of elevation-dependent patterns in other regions for comparative purposes, examination of long-term stream temperature records to understand how sensitivity to climate forcing may be evolving, use of new data sources to better represent key processes in temperature models across broad areas, and development of hybrid models that integrate the best attributes of mechanistic and statistical approaches.

Study on heat transfer performance of immersion system based on SiC/white mineral oil composite nanofluids

With the rapid development of the global digital economy, the number and size of data centers are also expanding. The high energy consumption of data centers has become a highly concerned issue in the industry. Immersion cooling is a thermal strategy for servers with high heat flux density in data centers. The low thermal conductivity of its working medium has become the main bottleneck hindering its application. In this study, the performance of heat transfer of the SiC/white mineral oil-based nanofluids as new coolant and oil as traditional coolant under different heat loads are presented. The heat transfer capacity in different application scenarios is explored. The results of the simulations show that with the new coolant, the maximum surface heat transfer coefficient of bare heat source is increased by 11.3% at 100 W. With heatsink and heat pipe auxiliary cooling, the maximum increase is 11.7% and 10.7%, respectively, at 300 W. The contour pictures reveal a considerable decrease of surface and internal high-temperature area using heatsink and heat pipe auxiliary cooling. The analysis of the economy and reliability of the new working fluid concludes that the PUE (Power usage effectiveness) of the new working fluid only increases by 0.07–0.03%, which is negligible. Lastly, after three months of repeated experiments, the average increase in temperature is 0.4–2.3%. It means that the new coolant has good stability and reliability, which proves it has good application prospect in submerged cooling system.