To analyze extreme climatic change features and effects on runoff in the Manas River basin, Xinjiang, data were collected including daily mean temperature, daily highest and lowest temperatures, and daily precipitatio...To analyze extreme climatic change features and effects on runoff in the Manas River basin, Xinjiang, data were collected including daily mean temperature, daily highest and lowest temperatures, and daily precipitation from six meteorological stations in the Manas River basin as well as daily runoff data from the Kensiwate hydrologic stations during 1960-2010. By adopting the threshold value of extreme climatic events defined by ET ALDDMI and with the aid of nonparametric statistical tests, Pearson III methods, and others, the effect of extreme climatic events on extreme runoff in the past 50 years in the Manas River basin, Xinjiang, was analyzed. The results showed that in the past 50 years, 1) extreme warming events (annual extreme maximum temperature, warm-day and warm-night index) have risen significantly (P < 0.05). Among these the warm-day and warm-night indices decreased abruptly in 2001 and 1996, respectively. With respect to extreme cold events (annual extreme minimum temperature, cold-day and cold-night indices), the extreme minimum temperature was high after 1976, and the cold-day index weakened significantly, similar to the cold-night index. 2) Except for the continuous drought days (CDD), the other five indices of extreme precipitation events appeared to trend upward, with an abrupt change around 1993. 3) Flood events in 1990, mostly in summer, accounted for 42.9% of the total number of floods since 1960. Floods increased mainly because extremely high summer temperatures increased snowmelt, increasing inflow to the rivers, which combined with more precipitation to cause the increase in summer peak flood discharge.展开更多
This study focuses on examining the characteristics of climate factors and extreme climate events in Northeast China during 1961- 2010 by using daily data from 104 stations, including surface air temperature, precipit...This study focuses on examining the characteristics of climate factors and extreme climate events in Northeast China during 1961- 2010 by using daily data from 104 stations, including surface air temperature, precipitation, wind speed, sunshine duration, and snow depth. Results show that annual mean temperature increased at a significant rate of 0.35℃ per decade, most notably in the Lesser Khingan Mountains and in winter. Annual rainfall had no obvious linear trend, while rainy days had a significant decreasing trend. So, the rain intensity increased. High-temperature days had a weak increasing trend, and low-temperature days and cold wave showed significant decreasing trends with rates of 3.9 d per decade and -0.64 times per decade, respectively. Frequency and spatial scope of low-temperature hazard reduced significantly. Warm days and warm nights significantly increased at 1.0 and 2.4 d per decade, while cold days and cold nights decreased significantly at -1.8 and -4.1 d per decade, respectively. The nighttime warming rate was much higher than that for daytime, indicating that nighttime warming had a greater contribution to the overall warming trend than daytime warming. The annual mean wind speed, gale days, and sunshine duration had significant decreasing trends at rates of-0.21 m s-1 per decade, -4.0 d per decade and -43.3 h per decade, respectively. The snow cover onset dates postponed at a rate of 1.2 d per decade, and the snow cover end date advanced at 1.5 d per decade, which leads to shorter snow cover duration by -2.7 d per decade. Meanwhile, the maximum snow depth decreased at -0.52 cm per decade. In addition, the snow cover duration shows a higher correlation with precipitation than with temperature, which suggests that precipitation plays a more important role in maintaining snow cover duration than temperature.展开更多
By using the observation data from 89 weather stations in Xinjiang during 1961-2010, this paper analyzed the basic climatic elements including temperature, precipitation, wind speed, sunshine duration, water vapor pre...By using the observation data from 89 weather stations in Xinjiang during 1961-2010, this paper analyzed the basic climatic elements including temperature, precipitation, wind speed, sunshine duration, water vapor pressure, and dust storm in the entire Xinjiang and the subareas: North Xinjiang, Tianshan Mountains, and South Xinjiang. The results indicate that from 1961 to 2010 the annual and seasonal mean temperatures in the entire Xinjiang show an increasing trend with the increasing rate rising from south to north. The increasing rate of annual mean minimum temperature is over twice more than that of the annual mean maximum temperature, contributing much to the increase in the annual averages. The magnitude of the decrease rate of low-temperature days is larger than the increase rate of high-temperature days. The increase of warm days and warm nights and the decrease of cold days and cold nights further reveal that the temperature increasing in Xinjiang is higher. In addition, annual and seasonal rainfalls have been increasing. South Xinjiang experiences higher increase in rainfall amounts than North Xinjiang and Tianshan Mountains. Annual rainy days, longest consecutive rainy days, the daily maximum precipitation and extreme precipitation events, annual torrential rain days and amount, annual blizzard days and amount, all show an increasing trend, corresponding to the increasing in annual mean water vapor pressure. This result shows that the humidity has increased with temperature increasing in the past 50 years. The decrease in annual mean wind speed and gale days lessen the impact of dust storm, sandstorm, and floating dust events. The increase in annual rainy days is the cause of the decrease in annual sunshine duration, while the increase in spring sunshine duration corresponds with the decrease in dust weather. Therefore, the increase in precipitation indicators, the decrease in gales and dust weather, and the increasing in sunshine duration in spring will be beneficial to crops growth.展开更多
Objective A total of 820 million tons of potash reserves are predicted to exist in the Palaeocene-Eocene of the Jianghan Basin. However, the basin history is still unclear concerning the potash enriching conditions a...Objective A total of 820 million tons of potash reserves are predicted to exist in the Palaeocene-Eocene of the Jianghan Basin. However, the basin history is still unclear concerning the potash enriching conditions and mechanism. The Well SKDI is the first exploration well drilled in the Paleogene of Jianghan Basin with continuous coring, which was implemented in the south-central Jiangling Basin in 2013. It is essential to study the Palaeocene-Eocene paleoclimate, to further constrain the extreme draught events and the potash forming conditions.展开更多
During phase II of the Regional Climate Model Inter-comparison Project (RMIP) for Asia, the Asian climate was estimated from July 1988 to December 1998 using six climate models. In this paper, the abilities of six c...During phase II of the Regional Climate Model Inter-comparison Project (RMIP) for Asia, the Asian climate was estimated from July 1988 to December 1998 using six climate models. In this paper, the abilities of six climate models to simulate several important ex- treme climate events in China during the last years of the last century were analyzed. The modeled results for the intensity of the precipitation anomaly over the Yang- tze-Huaihe Valley during the summers of 1991 and 1998 were weaker than the observed values. The positive pre- cipitation anomaly responsible for a catastrophic flood in 1991 was well reproduced in almost all simulation results, but the intensity and range of the precipitation anomaly in 1998 were weaker in the modeled results. The spatial dis- tribution of extreme climate events in 1997, when severe drought affected North China and flood impacted South China, was reproduced by most of the regional models because the anomaly of the large-scale background field was well-simulated, despite poor simulation of high temperature areas in the north during the summer by all models.展开更多
Daily climate data at 110 stations during 1961-2010 were selected to examine the changing characteristics of climate factors and extreme climate events in South China. The annual mean surface air temperature has incre...Daily climate data at 110 stations during 1961-2010 were selected to examine the changing characteristics of climate factors and extreme climate events in South China. The annual mean surface air temperature has increased significantly by 0.16℃ per decade, most notably in the Pearl River Delta and in winter. The increase rate of the annual extreme minimum temperature (0.48℃ per decade) is over twice that of the annual extreme maximum temperature (0.20℃ per decade), and the increase of the mean temperature is mainly the result of the increase of the extreme minimum temperature. The increase rate of high-temperature days (1.1 d per decade) is close to the decrease rate of low-temperature days (-1.3 d per decade). The rainfall has not shown any significant trend, but the number of rainy days has decreased and the rain intensity has increased. The regional mean sunshine duration has a significant decreasing trend of -40.9 h per decade, and the number of hazy days has a significant increasing trend of 6.3 d per decade. The decrease of sunshine duration is mainly caused by the increase of total cloud, not by the increase of hazy days in South China. Both the regional mean pan evaporation and mean wind speed have significant decreasing trends of -65.9 mm per decade and -0.11 m s-1 per decade, respectively. The decrease of both sunshine duration and mean wind speed plays an important role in the decrease of pan evaporation. The number of landing tropical cyclones has an insignificant decreasing trend of -0.6 per decade, but their intensities show a weak increasing trend. The formation location of tropical cyclones landing in South China has converged towards 10-19°N, and the landing position has shown a northward trend. The date of the first landfall tropical cyclone postpones 1.8 d per decade, and the date of the last landfall advances 3.6 d per decade, resulting in reduction of the typhoon season by 5.4 d per decade.展开更多
Daily maximum/minimum temperature and precipitation data from 35 weather stations in Xinjiang during 1961-2010 were examined using kriging spatial analysis, linear tendency estimation, and correlation analysis. Tempor...Daily maximum/minimum temperature and precipitation data from 35 weather stations in Xinjiang during 1961-2010 were examined using kriging spatial analysis, linear tendency estimation, and correlation analysis. Temporal trends and spatial distribution patterns of extreme temperature and precipitation in this area were then analyzed using 12 extreme temperature and 7 extreme precipitation indices. The following results were obtained. 1) Over the past 50 years, extreme cold indices, excepting the monthly maximum temperature minimum value and monthly extreme minimum temperature, showed slight decreasing trends. These indices include the maximum number of consecutive frost days, icy days, cold-nighttime days, and cold-daytime days. 2) Extreme warm events generally showed significant increasing trends (P < 0.01), including the indices of summertime days, warm-nighttime days, warm-daytime days, monthly extreme maximum temperature, and monthly minimum temperature maximum value. 3) The spatial distributions of threshold values of extreme warm and cold events showed notable regional differences. A reducing trend of extreme cold events and an increase in extreme warm events has occurred mainly in northern Xinjiang. 4) For the past 50 years, six extreme precipitation indices, aside from consecutive dry days, showed significant increasing trends in Xinjiang (P < 0.05) and notable differences in spatial distribution. The increase in extreme precipitation events was more rapid at northern than at southern sites. Extreme precipitation intensity was greater in mountainous areas, and precipitation frequency increased in the plain region. 5) Factor analysis revealed good correlations among extreme temperature indices, excepting extreme temperature days.展开更多
Polar climate systems have experienced a number of dramatic changes (Wang et al., 2017; Turner et al., 2016; Gordon, 2014; Rignot et al., 2013; Meier et al., 2012; Kwok and Rothrock, 2009; Thompson and Solomon, 2002...Polar climate systems have experienced a number of dramatic changes (Wang et al., 2017; Turner et al., 2016; Gordon, 2014; Rignot et al., 2013; Meier et al., 2012; Kwok and Rothrock, 2009; Thompson and Solomon, 2002), which have influenced climatic conditions across large parts of the globe through large-scale atmospheric and oceanic teleconnections (Dou and Wu, 2018; Zhang et al., 2018;展开更多
Climate change studies are diverse with no single study giving a comprehensive review of climate change impacts,adaptation strategies,and policy development in West Africa.The unavailability of an all-inclusive study ...Climate change studies are diverse with no single study giving a comprehensive review of climate change impacts,adaptation strategies,and policy development in West Africa.The unavailability of an all-inclusive study to serve as a guide for practitioners affects the effectiveness of climate change adaptation strategies proposed and adopted in the West African sub-region.The purpose of this study was to review the impacts of climate change risks on the crop,fishery,and livestock sectors,as well as the climate change adaptation strategies and climate-related policies aimed at helping to build resilient agricultural production systems in West Africa.The review process followed a series of rigorous stages until the final selection of 56 articles published from 2009 to 2023.Generally,the results highlighted the adverse effects of climate change risks on food security.We found a continuous decline in food crop production.Additionally,the livestock sector experienced morbidity and mortality,as well as reduction in meat and milk production.The fishery sector recorded loss of fingerlings,reduction in fish stocks,and destruction of mariculture and aquaculture.In West Africa,climate-smart agriculture technologies,physical protection of fishing,and inclusion of gender perspectives in programs appear to be the major adaptation strategies.The study therefore recommends the inclusion of ecosystem and biodiversity restoration,weather insurance,replacement of unsafe vessels,and strengthening gender equality in all climate change mitigation programs,as these will help to secure enough food for present and future generations.展开更多
China experienced significant flooding in the summer of 2020 and multiple extreme cold surges during the winter of 2020/21.Additionally,the 2020 typhoon season had below average activity with especially quiet activity...China experienced significant flooding in the summer of 2020 and multiple extreme cold surges during the winter of 2020/21.Additionally,the 2020 typhoon season had below average activity with especially quiet activity during the first half of the season in the western North Pacific(WNP).Sea surface temperature changes in the Pacific,Indian,and Atlantic Oceans all contributed to the heavy rainfall in China,but the Atlantic and Indian Oceans seem to have played dominant roles.Enhancement and movement of the Siberian High caused a wavier pattern in the jet stream that allowed cold polar air to reach southward,inducing cold surges in China.Large vertical wind shear and low humidity in the WNP were responsible for fewer typhoons in the first half of the typhoon season.Although it is known that global warming can increase the frequency of extreme weather and climate events,its influences on individual events still need to be quantified.Additionally,the extreme cold surge during 16–18 February 2021 in the United States shares similar mechanisms with the winter 2020/21 extreme cold surges in China.展开更多
Extreme climate events have profound impacts on economies and livelihoods of many regions of the world. In Kenya, the extreme climate events often have strong impacts on agriculture production systems in the Arid and ...Extreme climate events have profound impacts on economies and livelihoods of many regions of the world. In Kenya, the extreme climate events often have strong impacts on agriculture production systems in the Arid and Semi-Arid Lands (ASALs). A small change in the mean climate condition can cause large changes in these production systems. There is a paucity of information on trends in climate and climate extremes in the country. However, a joint World Meteorological Commission for Climatology/World Climate Research Programme (WCPRP) project on climate Variability and Predictability (WMO CCl/CLIVAR) Expert Team (ET) on Climate Change Detection, Monitoring and Indices has defined 27 core climate indices mainly focusing on extreme events which can be derived through the use of RClimDex Software. In this study, therefore, the RClimDex software has been used to derive climate extreme indices for five stations in the ASALs of South-Eastern Kenya based on climate data for the period 1961 to 2009. The objective was to examine trends in these extremes to aid agricultural planning and practice. These indices have shown decreasing trends in annual rainfall, rainfall intensity and consecutive wet days but increasing trends in consecutive dry days. Steady warming patterns were evident in both the maximum and minimum temperature indices. This paper concludes that indeed significant changes in climate extremes are apparent in the ASALs of the country and recommends a re-thinking of planning and practice of rain-fed agriculture in the ASALs of South-Eastern Kenya.展开更多
The China Meteorological Administration recently released China Polar Climate Change Annual Report(2022)in Chinese,with the following main conclusions.Using the China Reanalysis-40 dataset(CRA-40),rapid warming has be...The China Meteorological Administration recently released China Polar Climate Change Annual Report(2022)in Chinese,with the following main conclusions.Using the China Reanalysis-40 dataset(CRA-40),rapid warming has been observed in the Antarctic Peninsula and West Antarctica since 1979,with some parts of East Antarctica also experiencing warming.In 2022,the regional average temperature in Antarctica based on observational data was close to the long-term average(1991-2020).The Arctic,on the other hand,has experienced a warming trend at a rate of 0.63℃per decade from 1979 to 2022 based on CRA-40,which is 3.7 times the global mean during the same period(0.17℃per decade).In 2022,the overall temperature in the Arctic,using station data,was 1.10℃above the long-term average(1991-2020).In recent years,both the Antarctic and Arctic regions have witnessed an increase in the frequency and intensity of extreme weather events.In 2022,based on the sea ice extent from National Snow and Ice Data Center,USA,Antarctic sea ice reached its lowest extent on record since 1979,and on 18 March,the most rapid surface warming event ever recorded on Earth occurred in the Antarctic,with a temperature increase of 49℃within 3 d.This report has been integrated into China's National Climate Change Bulletin system,to contribute to raising public awareness of polar climate change and providing valuable scientific references to address climate change.展开更多
Soybean is an important oil crop.Agro-climatic resources and extreme climate events during the growing season directly affect the crop growth and grain yield.In this study,we used historical climate data and phenology...Soybean is an important oil crop.Agro-climatic resources and extreme climate events during the growing season directly affect the crop growth and grain yield.In this study,we used historical climate data and phenology observation data to investigate the spatial distributions and temporal trends of agro-climatic resources and extreme climate events during the growing season for soybean in Northeast China(NEC).The results showed that during the soybean growing season,the thermal time increased while both the effective precipitation and photosynthetically active radiation(PAR)decreased.Within the growing season,the thermal time increased by 44.0°C day decade–1 during the vegetative stage but decreased by 16.5°C day decade–1 during the reproductive stage;the effective precipitation increased by 1.8 mm decade–1 during the vegetative stage but decreased by 7.3 mm decade–1 during the reproductive stage;PAR decreased by 6.5 and 11.9 MJ m–2 decade–1 during the vegetative and reproductive stages.The frequency of extreme cold days showed a decreasing trend during the four study phases of sowing to emergence,sowing–flowering,15 days before flowering–flowering,and pod to physiological maturity.During the soybean growing season,the frequency of extreme heat days and the maximum number of consecutive dry days(CDD)increased,and the maximum number of consecutive wet days(CWD)and heavy precipitation days decreased.The results of this study could be used in selecting optimal management in soybean production in order to take advantage of beneficial climatic elements.展开更多
An unexpected super mei-yu struck in 2020 in the Yangtze-Huaihe River basin,southern Korea,and southern Japan(hereafter referred to as the mei-yu regions),causing many casualties and huge economic losses.The super mei...An unexpected super mei-yu struck in 2020 in the Yangtze-Huaihe River basin,southern Korea,and southern Japan(hereafter referred to as the mei-yu regions),causing many casualties and huge economic losses.The super mei-yu was characterized by a remarkably early onset(around 1 June),late withdrawal(around 1 August),and intense rainfalI during the mei-yu season.The precipitation in the early onset and late withdrawal stages contributed more than half of the total mei-yu-period precipitation over the mei-yu regions in 2020.In this study,the authors explored the dominant remote forcing of the mei-yu early onset and late withdrawal to understand the mechanisms of this super mei-yu.The early onset can mainly be attributed to an early northward-shifted East Asian jet stream(EAJS).The late withdrawal mainly resulted from the stagnant EAJS and the western North Pacific subtropical high(WPSH) during 10 July to 1 August.Specifically,North Atlantic sea surface temperature anomalies(SSTAs) excited a Rossby wave,which was steered by atmospheric anomalies related to the western North Pacific SSTAs,causing the early northward-shifted EAJS and generating an early onset.The record-breaking warm SSTAs over the North Indian Ocean to South China Sea and the reduced sea-ice concentration(SIC) over the Laptev-East Siberian Sea played important roles in causing the stagnant WPSH and EAJS during July,which led to the late withdrawal.Meanwhile,the SIC anomalies may have caused the inhomogeneous rainfall distribution in the mei-yu regions.Furthermore,projection results suggest that the probability of a late mei-yu withdrawal similar to the 2020 case will increase in the future.Finally,potential predictors of an extreme mei-yu are discussed.展开更多
The present study focused on statistical analysis of interannual, interdecadal variations of climate variables and extreme climate events during the period of 1961-2010 using observational data from 376 meteorological...The present study focused on statistical analysis of interannual, interdecadal variations of climate variables and extreme climate events during the period of 1961-2010 using observational data from 376 meteorological stations uniformly distributed across Southwest China, which includes Yunnan, Guizhou, Chongqing, Sichuan and Tibet. It was found that temperatures in most of the region were warming and this was especially evident for areas at high elevation. The warming was mostly attributable to the increase in annual mean minimum temperature. The characteristics of high temperature/heat waves are increase in frequency, prolonged duration, and weakened intensity. Annual precipitation showed a weak decreasing trend and drier in the east and more rainfall in the west. The precipitation amount in flood season was declining markedly in the whole region; rainfall from extreme heavy precipitation did not change much, and the portion of annual precipitation contributed by extreme heavy precipitation had an increasing trend; annual non-rainy days and the longest consecutive non-rainy days were both increasing; the extreme drought had a decreasing trend since the 1990s; the autumn-rain days displayed a downward fluctuation with apparent periodicity and intermittency. The number of southwestern vortices was decreasing whereas the number of moving vortices increased.展开更多
Between 1876 and 1878 a large-scale drought occurred in China. This is a major meteorological disaster and an extreme climate event despite the cold climate at the end of the Little Ice Age. In this paper the dynamic ...Between 1876 and 1878 a large-scale drought occurred in China. This is a major meteorological disaster and an extreme climate event despite the cold climate at the end of the Little Ice Age. In this paper the dynamic evolution of the occurrence and development of the drought is reproduced on the basis of historical literature records. These were used to calculate the yearly numbers of drought-hit counties and to determine the spatial distribution in addition with concomitant famine, locust plague and pestilence epidemic for each of the three years. The persistent drought disaster spread over 13 provinces with its center in Shaanxi, Henan and Shanxi provinces, where the continuous non-soaking rain period exceeded 340 days. Conclusively, it is more severe than the worst drought (1928-1930) in the 20th century. This drought disaster of 1876-1878 took place in the descending phase of the 11th sunspot activity period and the start of the 12th period. It also happened during a spell of frequent E1 Nino events and corresponds with an extremely strong E1 Nino.展开更多
In this study, observational data from 141 meteorological stations in Northwest China, including temperature, precipitation, dust storm, gale days and wind speed, were analyzed statistically to gain insight of the fea...In this study, observational data from 141 meteorological stations in Northwest China, including temperature, precipitation, dust storm, gale days and wind speed, were analyzed statistically to gain insight of the features of basic climate index and extreme climate events. The results showed that the annual mean temperature and seasonal mean temperature rose significantly, and the rising rate of the annual mean temperature is 0.27℃ per decade; the extreme high temperature days have increased; the interdecadal change of annual precipitation is marked, and the precipitation in winter and summer increased slightly, while decreased slightly in spring and autumn. The annual precipitation increased in the area west of the Yellow River, whereas decreased in the area east of the river. The drought had an increasing trend. There were 17 droughts during 1961-2010, and 10 droughts from 1991 to 2010. The number of droughts in spring and autumn increased, while decreased in summer.展开更多
Following disastrous flooding in several river valleys over eastern China in 1755, serious flooding occurred in the middle and lower reaches of the Yellow River in 1756 and 1757, a rarely seen precipitation pattern of...Following disastrous flooding in several river valleys over eastern China in 1755, serious flooding occurred in the middle and lower reaches of the Yellow River in 1756 and 1757, a rarely seen precipitation pattern of north-flood and south-drought in China for two successive years. This is a serious meteorological disaster and extreme climatic event taking place under the climatic background of a warm phase of the Little Ice Age. In this paper, by means of historical literature records, the rainy and flooding situation and the weather characteristics of these years are reconstructed and the maps depicting areas of prolonged rain, flood and concomitant famine, insect pest, and pestilence are made. The results show that, in 1755, the middle and lower reaches of the Yellow River and the Yangtze River, and the Huaihe River Basin experienced a prolonged rainy season with multiple torrential rain events. The continuous rainy period exceeded 40 days in the Huang-Huai Region. An early Meiyu occurred, and the duration of the Meiyu period in the lower Yangtze River Basin was 43 days, the longest in the 18th century. Particularly in Nanjing the annual rainfall of 1755 was 1,378 mm, the highest record of the 18th century. The year of 1755 is characterized by lower temperature in summer, early frost in autumn, and heavy snowfall and freezing rain in winter. These characteristics are extremely similar to those of 1823 and 1954, two typical years of extreme rainfall. And all these three years with extreme precipitation axe corresponding to the minimum phase of the solar activity cycle.展开更多
The spatial and temporal variations of some important near-surface climate parameters and extreme climate events in North China during 1961-2010 are analyzed by using 94 meteorological stations' data in the study are...The spatial and temporal variations of some important near-surface climate parameters and extreme climate events in North China during 1961-2010 are analyzed by using 94 meteorological stations' data in the study area. Results show that the annual mean surface air temperature in North China increased at the rate of 0.36℃ per decade, higher than the national average in the same period. Increasing was particularly significant since the mid-1980s, with maximum increase in the middle and northeastern parts of Inner Mongolia. Increasing rate of the annual mean minimum temperature is much higher than that of the maximum temperature, which results in the decrease of the annual mean diurnal temperature range. Noticeable decrease is also observed in the frequency of cold wave. Annual precipitation shows a slight decreasing trend, with more pronounced decrease in southern Shanxi and eastern Hebei provinces, which is mainly represented as decreasing in contribution rates of rainstorm and heavy storm in flood-season (May to September). During 1961 -2010, North China is characterized by a noticeable reduction in annual extreme precipitation, and an increase in high-temperature days over most parts, as well as more frequent droughts. There are remarkable reductions in annual sunshine duration and mean wind speed, associated with the most significant reduction of mean wind speed in midwestern and eastern parts of Inner Mongolia. Meanwhile, North China has experienced a noticeable decrease/increase in annual mean sanddust/haze days during the study period. However, there is no significant trend in fog days, except a pronounced decrease since the 1990s.展开更多
Climate change could intensify extreme weather events,such as flooding,which amplifies the public health threat of waterborne diseases.Thus,assessing health vulnerability and adaptation(V&A)could facilitate nation...Climate change could intensify extreme weather events,such as flooding,which amplifies the public health threat of waterborne diseases.Thus,assessing health vulnerability and adaptation(V&A)could facilitate nationally effective responses to extreme climate events.However,related studies are still negligible,and the assessment urgently needs to be validated with actual health data after extreme weather events.We established health V&A indices through literature review and factor analyses.Then,we separately mapped the spatial distribution of flood exposure,social and public health sensitivity,and adaptive capacity before the 2016 flood in Anhui province and compared it with post-flood diarrhea risks by using the geographic information system method to assess health vulnerability.Finally,we validated the indices by exploring the relationship between health V&A indices and post-flood diarrhea risks by using the quantile regression model.Results revealed that health V&A can be framed and categorized as key components of exposure,sensitivity,and adaptive capacity.The remarkable differences in the spatial distribution of health vulnerability were generally consistent with the demographic sensitivity,geographic flooding exposure,and post-flood diarrhea risks in Anhui.In addition,health V&A indices exerted significant positive impacts on infectious diarrhea post-flooding at all quantiles and were significant across different percentiles.Moreover,the impacts of flood exposure on total infectious diarrhea were high and continuous,whereas the impacts of sensitivity were not obvious in the flood's early stage(Coeff=0.643;p<0.001)but high in the flood's middle(Coeff=0.997;p<0.001)and late stages(Coeff=0.975;p<0.001).However,the impacts of adaptive capacity were heterogeneous and high in the flood's early stage(Coeff=0.665;p<0.001 at the 25th percentile)and late stage(Coeff=1.296;p<0.001 at the 75th percentile)but were insignificant at the 50th percentile.This study contributed validated three-layered health V&A indices with 30 indicators and identified that the impacts of the key components on post-flood waterborne-disease risks are heterogeneous.For instance,local public health sensitivity and adaptive capacity are insufficient to reduce these risks in the long run.This study could be used to project population health risks after extreme weather events and thereby contributes to local government planning of health adaptation.展开更多
文摘To analyze extreme climatic change features and effects on runoff in the Manas River basin, Xinjiang, data were collected including daily mean temperature, daily highest and lowest temperatures, and daily precipitation from six meteorological stations in the Manas River basin as well as daily runoff data from the Kensiwate hydrologic stations during 1960-2010. By adopting the threshold value of extreme climatic events defined by ET ALDDMI and with the aid of nonparametric statistical tests, Pearson III methods, and others, the effect of extreme climatic events on extreme runoff in the past 50 years in the Manas River basin, Xinjiang, was analyzed. The results showed that in the past 50 years, 1) extreme warming events (annual extreme maximum temperature, warm-day and warm-night index) have risen significantly (P < 0.05). Among these the warm-day and warm-night indices decreased abruptly in 2001 and 1996, respectively. With respect to extreme cold events (annual extreme minimum temperature, cold-day and cold-night indices), the extreme minimum temperature was high after 1976, and the cold-day index weakened significantly, similar to the cold-night index. 2) Except for the continuous drought days (CDD), the other five indices of extreme precipitation events appeared to trend upward, with an abrupt change around 1993. 3) Flood events in 1990, mostly in summer, accounted for 42.9% of the total number of floods since 1960. Floods increased mainly because extremely high summer temperatures increased snowmelt, increasing inflow to the rivers, which combined with more precipitation to cause the increase in summer peak flood discharge.
基金supported by the Special Climate Change Research Program of China Meteorological Ad-ministration (No.062700s010c01)the Special Scientific Research Fund of Meteorological Public Welfare Profession of China (No.201206024)
文摘This study focuses on examining the characteristics of climate factors and extreme climate events in Northeast China during 1961- 2010 by using daily data from 104 stations, including surface air temperature, precipitation, wind speed, sunshine duration, and snow depth. Results show that annual mean temperature increased at a significant rate of 0.35℃ per decade, most notably in the Lesser Khingan Mountains and in winter. Annual rainfall had no obvious linear trend, while rainy days had a significant decreasing trend. So, the rain intensity increased. High-temperature days had a weak increasing trend, and low-temperature days and cold wave showed significant decreasing trends with rates of 3.9 d per decade and -0.64 times per decade, respectively. Frequency and spatial scope of low-temperature hazard reduced significantly. Warm days and warm nights significantly increased at 1.0 and 2.4 d per decade, while cold days and cold nights decreased significantly at -1.8 and -4.1 d per decade, respectively. The nighttime warming rate was much higher than that for daytime, indicating that nighttime warming had a greater contribution to the overall warming trend than daytime warming. The annual mean wind speed, gale days, and sunshine duration had significant decreasing trends at rates of-0.21 m s-1 per decade, -4.0 d per decade and -43.3 h per decade, respectively. The snow cover onset dates postponed at a rate of 1.2 d per decade, and the snow cover end date advanced at 1.5 d per decade, which leads to shorter snow cover duration by -2.7 d per decade. Meanwhile, the maximum snow depth decreased at -0.52 cm per decade. In addition, the snow cover duration shows a higher correlation with precipitation than with temperature, which suggests that precipitation plays a more important role in maintaining snow cover duration than temperature.
基金supported by China Meteorological Administration (CMA) Specific Research on ClimateChange (No. CCSF-10-06)the National Key Scientific Research Program of Global Change (No. 2010CB951001)
文摘By using the observation data from 89 weather stations in Xinjiang during 1961-2010, this paper analyzed the basic climatic elements including temperature, precipitation, wind speed, sunshine duration, water vapor pressure, and dust storm in the entire Xinjiang and the subareas: North Xinjiang, Tianshan Mountains, and South Xinjiang. The results indicate that from 1961 to 2010 the annual and seasonal mean temperatures in the entire Xinjiang show an increasing trend with the increasing rate rising from south to north. The increasing rate of annual mean minimum temperature is over twice more than that of the annual mean maximum temperature, contributing much to the increase in the annual averages. The magnitude of the decrease rate of low-temperature days is larger than the increase rate of high-temperature days. The increase of warm days and warm nights and the decrease of cold days and cold nights further reveal that the temperature increasing in Xinjiang is higher. In addition, annual and seasonal rainfalls have been increasing. South Xinjiang experiences higher increase in rainfall amounts than North Xinjiang and Tianshan Mountains. Annual rainy days, longest consecutive rainy days, the daily maximum precipitation and extreme precipitation events, annual torrential rain days and amount, annual blizzard days and amount, all show an increasing trend, corresponding to the increasing in annual mean water vapor pressure. This result shows that the humidity has increased with temperature increasing in the past 50 years. The decrease in annual mean wind speed and gale days lessen the impact of dust storm, sandstorm, and floating dust events. The increase in annual rainy days is the cause of the decrease in annual sunshine duration, while the increase in spring sunshine duration corresponds with the decrease in dust weather. Therefore, the increase in precipitation indicators, the decrease in gales and dust weather, and the increasing in sunshine duration in spring will be beneficial to crops growth.
基金the National Science Foundation of China(Grants No.41502089,41302059 and 41202059)for their financial support
文摘Objective A total of 820 million tons of potash reserves are predicted to exist in the Palaeocene-Eocene of the Jianghan Basin. However, the basin history is still unclear concerning the potash enriching conditions and mechanism. The Well SKDI is the first exploration well drilled in the Paleogene of Jianghan Basin with continuous coring, which was implemented in the south-central Jiangling Basin in 2013. It is essential to study the Palaeocene-Eocene paleoclimate, to further constrain the extreme draught events and the potash forming conditions.
基金supported by the National Key Program for Developing Basic Sciences of China (Grant No.2009CB723904)the General Project of the National Natural Science Foundation of China (Grant No. 40975048)the Innovation Key Program of the Chinese Academy of Sciences (Grant No.KGCX2-YW-356)
文摘During phase II of the Regional Climate Model Inter-comparison Project (RMIP) for Asia, the Asian climate was estimated from July 1988 to December 1998 using six climate models. In this paper, the abilities of six climate models to simulate several important ex- treme climate events in China during the last years of the last century were analyzed. The modeled results for the intensity of the precipitation anomaly over the Yang- tze-Huaihe Valley during the summers of 1991 and 1998 were weaker than the observed values. The positive pre- cipitation anomaly responsible for a catastrophic flood in 1991 was well reproduced in almost all simulation results, but the intensity and range of the precipitation anomaly in 1998 were weaker in the modeled results. The spatial dis- tribution of extreme climate events in 1997, when severe drought affected North China and flood impacted South China, was reproduced by most of the regional models because the anomaly of the large-scale background field was well-simulated, despite poor simulation of high temperature areas in the north during the summer by all models.
基金supported by the Special Climate Change Research Program of China Meteorological Administration (No. CCSF-09-11, CCSF-09-03, CCSF2011-25, and CCSF201211)the Science and Technology Planning Project of Guangdong province (No.2011A030200021)
文摘Daily climate data at 110 stations during 1961-2010 were selected to examine the changing characteristics of climate factors and extreme climate events in South China. The annual mean surface air temperature has increased significantly by 0.16℃ per decade, most notably in the Pearl River Delta and in winter. The increase rate of the annual extreme minimum temperature (0.48℃ per decade) is over twice that of the annual extreme maximum temperature (0.20℃ per decade), and the increase of the mean temperature is mainly the result of the increase of the extreme minimum temperature. The increase rate of high-temperature days (1.1 d per decade) is close to the decrease rate of low-temperature days (-1.3 d per decade). The rainfall has not shown any significant trend, but the number of rainy days has decreased and the rain intensity has increased. The regional mean sunshine duration has a significant decreasing trend of -40.9 h per decade, and the number of hazy days has a significant increasing trend of 6.3 d per decade. The decrease of sunshine duration is mainly caused by the increase of total cloud, not by the increase of hazy days in South China. Both the regional mean pan evaporation and mean wind speed have significant decreasing trends of -65.9 mm per decade and -0.11 m s-1 per decade, respectively. The decrease of both sunshine duration and mean wind speed plays an important role in the decrease of pan evaporation. The number of landing tropical cyclones has an insignificant decreasing trend of -0.6 per decade, but their intensities show a weak increasing trend. The formation location of tropical cyclones landing in South China has converged towards 10-19°N, and the landing position has shown a northward trend. The date of the first landfall tropical cyclone postpones 1.8 d per decade, and the date of the last landfall advances 3.6 d per decade, resulting in reduction of the typhoon season by 5.4 d per decade.
文摘Daily maximum/minimum temperature and precipitation data from 35 weather stations in Xinjiang during 1961-2010 were examined using kriging spatial analysis, linear tendency estimation, and correlation analysis. Temporal trends and spatial distribution patterns of extreme temperature and precipitation in this area were then analyzed using 12 extreme temperature and 7 extreme precipitation indices. The following results were obtained. 1) Over the past 50 years, extreme cold indices, excepting the monthly maximum temperature minimum value and monthly extreme minimum temperature, showed slight decreasing trends. These indices include the maximum number of consecutive frost days, icy days, cold-nighttime days, and cold-daytime days. 2) Extreme warm events generally showed significant increasing trends (P < 0.01), including the indices of summertime days, warm-nighttime days, warm-daytime days, monthly extreme maximum temperature, and monthly minimum temperature maximum value. 3) The spatial distributions of threshold values of extreme warm and cold events showed notable regional differences. A reducing trend of extreme cold events and an increase in extreme warm events has occurred mainly in northern Xinjiang. 4) For the past 50 years, six extreme precipitation indices, aside from consecutive dry days, showed significant increasing trends in Xinjiang (P < 0.05) and notable differences in spatial distribution. The increase in extreme precipitation events was more rapid at northern than at southern sites. Extreme precipitation intensity was greater in mountainous areas, and precipitation frequency increased in the plain region. 5) Factor analysis revealed good correlations among extreme temperature indices, excepting extreme temperature days.
基金funded by the Fundamental Research Funds for the Central Universities (Grant nos.2017B04814,2017B20714),Hohai UniversityState Key Laboratory of Satellite Ocean Environment Dynamics+1 种基金supported by the Global Change Research Program of China (Grant no.2015CB953904)the National Natural Science Foundation of China (NSFC,Grant no.41876220)
文摘Polar climate systems have experienced a number of dramatic changes (Wang et al., 2017; Turner et al., 2016; Gordon, 2014; Rignot et al., 2013; Meier et al., 2012; Kwok and Rothrock, 2009; Thompson and Solomon, 2002), which have influenced climatic conditions across large parts of the globe through large-scale atmospheric and oceanic teleconnections (Dou and Wu, 2018; Zhang et al., 2018;
文摘Climate change studies are diverse with no single study giving a comprehensive review of climate change impacts,adaptation strategies,and policy development in West Africa.The unavailability of an all-inclusive study to serve as a guide for practitioners affects the effectiveness of climate change adaptation strategies proposed and adopted in the West African sub-region.The purpose of this study was to review the impacts of climate change risks on the crop,fishery,and livestock sectors,as well as the climate change adaptation strategies and climate-related policies aimed at helping to build resilient agricultural production systems in West Africa.The review process followed a series of rigorous stages until the final selection of 56 articles published from 2009 to 2023.Generally,the results highlighted the adverse effects of climate change risks on food security.We found a continuous decline in food crop production.Additionally,the livestock sector experienced morbidity and mortality,as well as reduction in meat and milk production.The fishery sector recorded loss of fingerlings,reduction in fish stocks,and destruction of mariculture and aquaculture.In West Africa,climate-smart agriculture technologies,physical protection of fishing,and inclusion of gender perspectives in programs appear to be the major adaptation strategies.The study therefore recommends the inclusion of ecosystem and biodiversity restoration,weather insurance,replacement of unsafe vessels,and strengthening gender equality in all climate change mitigation programs,as these will help to secure enough food for present and future generations.
基金the National Natural Science Foundation of China(Grant No.41731173)the National Key R&D Program of China(Grant No.2019YFA0606701)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant Nos.XDB42000000 and XDA20060502)the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(Grant No.GML2019ZD0306)the Innovation Academy of South China Sea Ecology and Environmental Engineering,the Chinese Academy of Sciences(Grant No.ISEE2018PY06)。
文摘China experienced significant flooding in the summer of 2020 and multiple extreme cold surges during the winter of 2020/21.Additionally,the 2020 typhoon season had below average activity with especially quiet activity during the first half of the season in the western North Pacific(WNP).Sea surface temperature changes in the Pacific,Indian,and Atlantic Oceans all contributed to the heavy rainfall in China,but the Atlantic and Indian Oceans seem to have played dominant roles.Enhancement and movement of the Siberian High caused a wavier pattern in the jet stream that allowed cold polar air to reach southward,inducing cold surges in China.Large vertical wind shear and low humidity in the WNP were responsible for fewer typhoons in the first half of the typhoon season.Although it is known that global warming can increase the frequency of extreme weather and climate events,its influences on individual events still need to be quantified.Additionally,the extreme cold surge during 16–18 February 2021 in the United States shares similar mechanisms with the winter 2020/21 extreme cold surges in China.
文摘Extreme climate events have profound impacts on economies and livelihoods of many regions of the world. In Kenya, the extreme climate events often have strong impacts on agriculture production systems in the Arid and Semi-Arid Lands (ASALs). A small change in the mean climate condition can cause large changes in these production systems. There is a paucity of information on trends in climate and climate extremes in the country. However, a joint World Meteorological Commission for Climatology/World Climate Research Programme (WCPRP) project on climate Variability and Predictability (WMO CCl/CLIVAR) Expert Team (ET) on Climate Change Detection, Monitoring and Indices has defined 27 core climate indices mainly focusing on extreme events which can be derived through the use of RClimDex Software. In this study, therefore, the RClimDex software has been used to derive climate extreme indices for five stations in the ASALs of South-Eastern Kenya based on climate data for the period 1961 to 2009. The objective was to examine trends in these extremes to aid agricultural planning and practice. These indices have shown decreasing trends in annual rainfall, rainfall intensity and consecutive wet days but increasing trends in consecutive dry days. Steady warming patterns were evident in both the maximum and minimum temperature indices. This paper concludes that indeed significant changes in climate extremes are apparent in the ASALs of the country and recommends a re-thinking of planning and practice of rain-fed agriculture in the ASALs of South-Eastern Kenya.
基金supported by the National Science Foundation of China (Grant no.42122047)the Basic Fund of the Chinese Academy of Meteorological Sciences (Grant nos.2021Z006 and 2023Z025)。
文摘The China Meteorological Administration recently released China Polar Climate Change Annual Report(2022)in Chinese,with the following main conclusions.Using the China Reanalysis-40 dataset(CRA-40),rapid warming has been observed in the Antarctic Peninsula and West Antarctica since 1979,with some parts of East Antarctica also experiencing warming.In 2022,the regional average temperature in Antarctica based on observational data was close to the long-term average(1991-2020).The Arctic,on the other hand,has experienced a warming trend at a rate of 0.63℃per decade from 1979 to 2022 based on CRA-40,which is 3.7 times the global mean during the same period(0.17℃per decade).In 2022,the overall temperature in the Arctic,using station data,was 1.10℃above the long-term average(1991-2020).In recent years,both the Antarctic and Arctic regions have witnessed an increase in the frequency and intensity of extreme weather events.In 2022,based on the sea ice extent from National Snow and Ice Data Center,USA,Antarctic sea ice reached its lowest extent on record since 1979,and on 18 March,the most rapid surface warming event ever recorded on Earth occurred in the Antarctic,with a temperature increase of 49℃within 3 d.This report has been integrated into China's National Climate Change Bulletin system,to contribute to raising public awareness of polar climate change and providing valuable scientific references to address climate change.
基金Supported by the National Key Research and Development Program of China(2019YFA0607402)。
文摘Soybean is an important oil crop.Agro-climatic resources and extreme climate events during the growing season directly affect the crop growth and grain yield.In this study,we used historical climate data and phenology observation data to investigate the spatial distributions and temporal trends of agro-climatic resources and extreme climate events during the growing season for soybean in Northeast China(NEC).The results showed that during the soybean growing season,the thermal time increased while both the effective precipitation and photosynthetically active radiation(PAR)decreased.Within the growing season,the thermal time increased by 44.0°C day decade–1 during the vegetative stage but decreased by 16.5°C day decade–1 during the reproductive stage;the effective precipitation increased by 1.8 mm decade–1 during the vegetative stage but decreased by 7.3 mm decade–1 during the reproductive stage;PAR decreased by 6.5 and 11.9 MJ m–2 decade–1 during the vegetative and reproductive stages.The frequency of extreme cold days showed a decreasing trend during the four study phases of sowing to emergence,sowing–flowering,15 days before flowering–flowering,and pod to physiological maturity.During the soybean growing season,the frequency of extreme heat days and the maximum number of consecutive dry days(CDD)increased,and the maximum number of consecutive wet days(CWD)and heavy precipitation days decreased.The results of this study could be used in selecting optimal management in soybean production in order to take advantage of beneficial climatic elements.
基金supported by the National Natural Science Foundation of China [grant number 42088101]the Major Program of the National Natural Science Foundation of China [grant number 41991283]。
文摘An unexpected super mei-yu struck in 2020 in the Yangtze-Huaihe River basin,southern Korea,and southern Japan(hereafter referred to as the mei-yu regions),causing many casualties and huge economic losses.The super mei-yu was characterized by a remarkably early onset(around 1 June),late withdrawal(around 1 August),and intense rainfalI during the mei-yu season.The precipitation in the early onset and late withdrawal stages contributed more than half of the total mei-yu-period precipitation over the mei-yu regions in 2020.In this study,the authors explored the dominant remote forcing of the mei-yu early onset and late withdrawal to understand the mechanisms of this super mei-yu.The early onset can mainly be attributed to an early northward-shifted East Asian jet stream(EAJS).The late withdrawal mainly resulted from the stagnant EAJS and the western North Pacific subtropical high(WPSH) during 10 July to 1 August.Specifically,North Atlantic sea surface temperature anomalies(SSTAs) excited a Rossby wave,which was steered by atmospheric anomalies related to the western North Pacific SSTAs,causing the early northward-shifted EAJS and generating an early onset.The record-breaking warm SSTAs over the North Indian Ocean to South China Sea and the reduced sea-ice concentration(SIC) over the Laptev-East Siberian Sea played important roles in causing the stagnant WPSH and EAJS during July,which led to the late withdrawal.Meanwhile,the SIC anomalies may have caused the inhomogeneous rainfall distribution in the mei-yu regions.Furthermore,projection results suggest that the probability of a late mei-yu withdrawal similar to the 2020 case will increase in the future.Finally,potential predictors of an extreme mei-yu are discussed.
基金supported by the special climate change in 2010 of the China Meteorological Administration (No. ccfs-2010)the National Natural Science Foundation of China (No. 41275097)
文摘The present study focused on statistical analysis of interannual, interdecadal variations of climate variables and extreme climate events during the period of 1961-2010 using observational data from 376 meteorological stations uniformly distributed across Southwest China, which includes Yunnan, Guizhou, Chongqing, Sichuan and Tibet. It was found that temperatures in most of the region were warming and this was especially evident for areas at high elevation. The warming was mostly attributable to the increase in annual mean minimum temperature. The characteristics of high temperature/heat waves are increase in frequency, prolonged duration, and weakened intensity. Annual precipitation showed a weak decreasing trend and drier in the east and more rainfall in the west. The precipitation amount in flood season was declining markedly in the whole region; rainfall from extreme heavy precipitation did not change much, and the portion of annual precipitation contributed by extreme heavy precipitation had an increasing trend; annual non-rainy days and the longest consecutive non-rainy days were both increasing; the extreme drought had a decreasing trend since the 1990s; the autumn-rain days displayed a downward fluctuation with apparent periodicity and intermittency. The number of southwestern vortices was decreasing whereas the number of moving vortices increased.
基金supported by the National Science and Technology Support Program of China under Grant No.2007BAC29B-01,and Grant No. 2010CB950103 under China Global Change Research Program
文摘Between 1876 and 1878 a large-scale drought occurred in China. This is a major meteorological disaster and an extreme climate event despite the cold climate at the end of the Little Ice Age. In this paper the dynamic evolution of the occurrence and development of the drought is reproduced on the basis of historical literature records. These were used to calculate the yearly numbers of drought-hit counties and to determine the spatial distribution in addition with concomitant famine, locust plague and pestilence epidemic for each of the three years. The persistent drought disaster spread over 13 provinces with its center in Shaanxi, Henan and Shanxi provinces, where the continuous non-soaking rain period exceeded 340 days. Conclusively, it is more severe than the worst drought (1928-1930) in the 20th century. This drought disaster of 1876-1878 took place in the descending phase of the 11th sunspot activity period and the start of the 12th period. It also happened during a spell of frequent E1 Nino events and corresponds with an extremely strong E1 Nino.
基金supported by the Special Project on Climate Change in China Meteorological Administation(No. CCSF2010-5)
文摘In this study, observational data from 141 meteorological stations in Northwest China, including temperature, precipitation, dust storm, gale days and wind speed, were analyzed statistically to gain insight of the features of basic climate index and extreme climate events. The results showed that the annual mean temperature and seasonal mean temperature rose significantly, and the rising rate of the annual mean temperature is 0.27℃ per decade; the extreme high temperature days have increased; the interdecadal change of annual precipitation is marked, and the precipitation in winter and summer increased slightly, while decreased slightly in spring and autumn. The annual precipitation increased in the area west of the Yellow River, whereas decreased in the area east of the river. The drought had an increasing trend. There were 17 droughts during 1961-2010, and 10 droughts from 1991 to 2010. The number of droughts in spring and autumn increased, while decreased in summer.
基金supported in part by the China Global Change Research Program(No.2010CB950103)the National Science and Technology Support Program of China(No.2007BAC29B01)
文摘Following disastrous flooding in several river valleys over eastern China in 1755, serious flooding occurred in the middle and lower reaches of the Yellow River in 1756 and 1757, a rarely seen precipitation pattern of north-flood and south-drought in China for two successive years. This is a serious meteorological disaster and extreme climatic event taking place under the climatic background of a warm phase of the Little Ice Age. In this paper, by means of historical literature records, the rainy and flooding situation and the weather characteristics of these years are reconstructed and the maps depicting areas of prolonged rain, flood and concomitant famine, insect pest, and pestilence are made. The results show that, in 1755, the middle and lower reaches of the Yellow River and the Yangtze River, and the Huaihe River Basin experienced a prolonged rainy season with multiple torrential rain events. The continuous rainy period exceeded 40 days in the Huang-Huai Region. An early Meiyu occurred, and the duration of the Meiyu period in the lower Yangtze River Basin was 43 days, the longest in the 18th century. Particularly in Nanjing the annual rainfall of 1755 was 1,378 mm, the highest record of the 18th century. The year of 1755 is characterized by lower temperature in summer, early frost in autumn, and heavy snowfall and freezing rain in winter. These characteristics are extremely similar to those of 1823 and 1954, two typical years of extreme rainfall. And all these three years with extreme precipitation axe corresponding to the minimum phase of the solar activity cycle.
基金supported by the Climate Change Special Foundation of China Meteorological Administration(No. CCSF2010-1)
文摘The spatial and temporal variations of some important near-surface climate parameters and extreme climate events in North China during 1961-2010 are analyzed by using 94 meteorological stations' data in the study area. Results show that the annual mean surface air temperature in North China increased at the rate of 0.36℃ per decade, higher than the national average in the same period. Increasing was particularly significant since the mid-1980s, with maximum increase in the middle and northeastern parts of Inner Mongolia. Increasing rate of the annual mean minimum temperature is much higher than that of the maximum temperature, which results in the decrease of the annual mean diurnal temperature range. Noticeable decrease is also observed in the frequency of cold wave. Annual precipitation shows a slight decreasing trend, with more pronounced decrease in southern Shanxi and eastern Hebei provinces, which is mainly represented as decreasing in contribution rates of rainstorm and heavy storm in flood-season (May to September). During 1961 -2010, North China is characterized by a noticeable reduction in annual extreme precipitation, and an increase in high-temperature days over most parts, as well as more frequent droughts. There are remarkable reductions in annual sunshine duration and mean wind speed, associated with the most significant reduction of mean wind speed in midwestern and eastern parts of Inner Mongolia. Meanwhile, North China has experienced a noticeable decrease/increase in annual mean sanddust/haze days during the study period. However, there is no significant trend in fog days, except a pronounced decrease since the 1990s.
基金This study was supported by grants from the National Natural Science Foundation of China(71774179)the National Key R&D Program of China(2018YFA0606200)+1 种基金National Natural Science Foundation of China(71804205)the Government Reform and Construction of Key Bases of Ministry of Education(16JJD630011).
文摘Climate change could intensify extreme weather events,such as flooding,which amplifies the public health threat of waterborne diseases.Thus,assessing health vulnerability and adaptation(V&A)could facilitate nationally effective responses to extreme climate events.However,related studies are still negligible,and the assessment urgently needs to be validated with actual health data after extreme weather events.We established health V&A indices through literature review and factor analyses.Then,we separately mapped the spatial distribution of flood exposure,social and public health sensitivity,and adaptive capacity before the 2016 flood in Anhui province and compared it with post-flood diarrhea risks by using the geographic information system method to assess health vulnerability.Finally,we validated the indices by exploring the relationship between health V&A indices and post-flood diarrhea risks by using the quantile regression model.Results revealed that health V&A can be framed and categorized as key components of exposure,sensitivity,and adaptive capacity.The remarkable differences in the spatial distribution of health vulnerability were generally consistent with the demographic sensitivity,geographic flooding exposure,and post-flood diarrhea risks in Anhui.In addition,health V&A indices exerted significant positive impacts on infectious diarrhea post-flooding at all quantiles and were significant across different percentiles.Moreover,the impacts of flood exposure on total infectious diarrhea were high and continuous,whereas the impacts of sensitivity were not obvious in the flood's early stage(Coeff=0.643;p<0.001)but high in the flood's middle(Coeff=0.997;p<0.001)and late stages(Coeff=0.975;p<0.001).However,the impacts of adaptive capacity were heterogeneous and high in the flood's early stage(Coeff=0.665;p<0.001 at the 25th percentile)and late stage(Coeff=1.296;p<0.001 at the 75th percentile)but were insignificant at the 50th percentile.This study contributed validated three-layered health V&A indices with 30 indicators and identified that the impacts of the key components on post-flood waterborne-disease risks are heterogeneous.For instance,local public health sensitivity and adaptive capacity are insufficient to reduce these risks in the long run.This study could be used to project population health risks after extreme weather events and thereby contributes to local government planning of health adaptation.