Global warming has led to the frequent occurrence of extreme climatic events(ECEs)in the ecologically frag ile Qinghai-Xizang Plateau.Rural households face strong barriers in adaption,and food production is seriously ...Global warming has led to the frequent occurrence of extreme climatic events(ECEs)in the ecologically frag ile Qinghai-Xizang Plateau.Rural households face strong barriers in adaption,and food production is seriously threatened.Current methods for increasing household adaptability take a holistic point of view,but do not ac curately identify groups experiencing different adaptive barriers.To better identify different barriers,this paper examines natural,economic,cognitive,and technical barriers.A total of 17 indicators were selected to com prehensively evaluate the degree of barriers to crops adaptation in response to ECEs.Key factors were further analyzed to identify paths to break down the barriers.The results showed the following.(1)Natural barriers were present at the highest degree,economic barriers appear to be smallest,and the overall barriers were bi ased towards the lower quartile.10.82%of the households with the highest barriers.(2)67.38%of households report taking adaptive measures in crops production.The increase of the barriers leads to an increase and then a decrease in the possibility of adaptive behavior.(3)Addressing technical barriers is key to rapidly increasing household adaptive behavior in response to ECEs.The study provides recommendations for local governments to improve household adaptation behavior from two perspectives:short-term and long-term optimization path ways.This study can help governments quickly locate households with different classes of barriers,and propose more targeted adaptation policies.The ultimate goal is to ensure the sustainability of crops production and the well-being of households in northeastern part of the Qinghai-Xizang Plateau.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
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
The inner shelf mud wedge(ISMW)located in the East China Sea(ECS)is the fine-grained sedimentary area with high sedimentation rate and has provided an ideal study area for understanding the East Asian Summer Monsoon(E...The inner shelf mud wedge(ISMW)located in the East China Sea(ECS)is the fine-grained sedimentary area with high sedimentation rate and has provided an ideal study area for understanding the East Asian Summer Monsoon(EASM)evolution during the Holocene.In this paper,we presented the high-resolution geochemical data of the sediments from the core MD06-3040 in the ISMW of the ECS determined by X-ray fluorescence core scanning(XRF-CS)analysis,a high-resolution,continuous,and multielement method.Geochemical and factor analysis results reveal that the variations of elemental compositions(Al,Si,K,Ti,Fe),the elemental ratios of Al/Zr,Ca/Ti and Rb/Sr,and the factor scores(F1 are correlated with the changes of the EASM during the period of 6000–1300 cal yr BP.The higher values of geochemical compositions indicating the terrigenous inputs implied the intensification of anthropogenic activities after 1300 cal yr BP.Meanwhile,the significant decrease of most geochemical compositions and the F1 factor scores during 4500–3500 cal yr BP and 1700–1500 cal yr BP,within the dating errors,coincided with the weak EASM events(presumably drought and cold events).The spectral analysis results of K concentrations,Al/Zr ratios and F1 factor scores show the millennial and centennial climatic fluctuations,which are consistent with other marine sedimentary records in the adjacent areas.All the findings show that the geochemical compositions of sediments from core MD06-3040 are influenced by the EASM evolution,the variable El Niño/Southern Oscillation(ENSO)and the local oceanic thermohaline circulation(e.g.,Kuroshio Current).These results are greatly helpful in uncovering the forcing mechanism of the monsoonal climate in the east China over the Holocene and also contribute to the understanding of EASM variability.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
Extreme weather events pose an ever-greater threat to people,infrastructure,and nature.Forest ecosystems are highly sensitive to extreme cold events that can disrupt ecosystem functions,especially in montane regions.I...Extreme weather events pose an ever-greater threat to people,infrastructure,and nature.Forest ecosystems are highly sensitive to extreme cold events that can disrupt ecosystem functions,especially in montane regions.Ice storms can be particularly destructive,with rapid ice accretion causing tree branches to break,even snapping or uprooting entire trees.In March 2022,the Shennongjia forest in central China experienced severe ice storm conditions that severely damaged over 230,300ha.We utilized this opportunity to assess the vulnerability of different tree types(coniferous,deciduous,and evergreen broad-leaved)and stand compositions to damage resulting from ice glaze along an elevation gradient from 1,200 to 2,400m a.s.l.Among the 7,144 trees surveyed,10.1%suffered some extent of damage,which was most prolific in the middle elevation zone.While 96.8%of all damage occurred to deciduous broadleaved trees that dominated the forest community,the most severe damage(uprooting and lower trunk breakage)occurred to coniferous trees.The extent and severity of tree damage were moderated by forest composition,with secondary effects of forest structure and slope.Abiotic factors predominantly affected coniferous trees.We emphasize that more research and monitoring are needed to better understand the full impact of extreme weather events on forests,especially as the frequency and intensity of these events increases due to climate change.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
Wide collection on the historic records of the climatic changes and flood events is performed in the Yangtze Delta. Man-Kendall (MK) method is applied to explore the changing trends of the time series of the flood dis...Wide collection on the historic records of the climatic changes and flood events is performed in the Yangtze Delta. Man-Kendall (MK) method is applied to explore the changing trends of the time series of the flood discharge and the maximum high summer temperature. The research results indicate that the flood magnitudes increased during the transition from the medieval warm interval into the early Little Ice Age. Fluctuating climate changes of the Little Ice Age characterized by arid climate events followed by the humid and cold climate conditions give rise to the frequent flood hazards. Low-lying terrain made the study region prone to the flood hazards, storm tide and typhoon. MK analysis reveals that the jumping point of the time series of the flood discharge changes occurred in the mid-1960s, that of the maximum summer temperature changes in the mid-1990s, and the exact jump point in 1993. The flood discharge changes are on negative trend before the 1990s, they are on positive tendency after the 1990s; the maximum high summer temperature changes are on negative trend before the 1990s and on positive tendency after the 1990s. These results indicate that the trend of flood discharge matches that of the maximum high summer temperature in the Yangtze Delta. The occurrence probability of the maximum high summer temperature will be increasing under the climatic warming scenario and which will in turn increase the occurrence probability of the flood events. More active solar action epochs and the higher sea surface temperature index (SST index) of the south Pacific Ocean area lying between 4 o N-4 o S and 150 o W-90 o W correspond to increased annual precipitation, flood discharge and occurrence frequency of floods in the Yangtze Delta. This is partly because the intensified solar activities and the higher SST index give rise to accelerated hydrological circulation from ocean surface to the continent, resulting in increased precipitation on the continent.展开更多
Compound extreme climate events may profoundly affect human activity in the Yangtze River Basin.This study analyzed the long-term spatiotemporal distribution characteristics of compound heatwave-drought and heatwave-w...Compound extreme climate events may profoundly affect human activity in the Yangtze River Basin.This study analyzed the long-term spatiotemporal distribution characteristics of compound heatwave-drought and heatwave-waterlogging events in the Yangtze River Basin using multi-period historical observation data and future scenario climate model data.It also examined the changes in population exposure to compound extreme climate events in the basin and their driving factors by combining population statistics and forecast data.The results show that the occurrence days of compound heatwave-drought and heatwave-waterlogging events in the Yangtze River Basin have shown a significant upward trend both in historical periods and future scenarios,accompanied by a marked expansion in the affected areas.Compared to historical periods,population exposure in the Yangtze River Basin under future scenarios is expected to increase by 1.5–2 times,primarily concentrated in the key urban areas of the basin.The main factors driving the changes in population exposure are the increased frequency of extreme climate events and population decline in future scenarios.These findings provide scientific evidence for early mitigation of meteorological disasters in the Yangtze River Basin.展开更多
In the summer of 2024, following a strong El Ni?o event in the preceding winter, the tropical Indian Ocean and tropical North Atlantic recorded their highest SSTs since 1961, along with a significant westward shift an...In the summer of 2024, following a strong El Ni?o event in the preceding winter, the tropical Indian Ocean and tropical North Atlantic recorded their highest SSTs since 1961, along with a significant westward shift and intensification of the western Pacific subtropical high(WPSH). Under these conditions, China experienced its hottest summer since 1961,and was hit by a series of high-impact extreme weather and climate events. From 9 June to 2 July, southern China experienced an unprecedented extreme precipitation event that exceeded the well-known 1998 summer precipitation event in both duration and impact scope, resulting in devastating floods in the Yangtze River basin. Subsequently, in early to midJuly, the Huanghe-Huaihe Basin suffered from a severe drought–flood abrupt alternation event, heavily affecting Henan and Shandong. Meanwhile, southern China underwent a widespread heatwave event lasting 74 days, ranking as the second most intense since 1961. From late July to the end of August, northern China faced unusually frequent heavy precipitation events, with cumulative precipitation reaching the second highest for the same period since 1961, causing floods in many rivers of northern China. This study provides a timely summary and assessment of the characteristics and impacts of these extreme events. It serves as a reference for climate change research, including mechanism analysis, numerical simulation,and climate event attribution, and also offers valuable insights for improving meteorological disaster prevention and mitigation strategies.展开更多
General history of disasters in China suggests that China has frequently experienced two major natural disasters in its long history,one is from catastrophic earthquake events,and the other is from extreme climatic ev...General history of disasters in China suggests that China has frequently experienced two major natural disasters in its long history,one is from catastrophic earthquake events,and the other is from extreme climatic events,due to its unique active tectonic environment and climatic complexity.Although these two major natural disasters have caused great damage to human society,it remains unclear whether and how they affect Chinese dynasty alternation on decadal(emperor)timescales.Based on detailed comparisons between abrupt climatic changes,catastrophic seismic activities,and the history of Chinese dynasty alternation from 1000–2000 AD,we conclude that on decadal timescales,extreme drought(and/or flood)events could indeed significantly reduce agricultural production,cause severe food shortages and famine,and result in increases in population exile,rising food prices and inflation,and insufficient supplies for military defense,which could exceed social resilience and eventually lead to financial risks and social upheavals of the dynasties.In addition,catastrophic seismic events in the densely populated,agricultural areas of China,including the 1303 surface wave magnitude(M_(s))8.0 Hongtong earthquake,the 1556 M_(s)8.25Huaxian earthquake and the 1920 M_(s)8.5 Haiyuan earthquake,caused more than 200,000casualties and millions of victims to live in exile which was almost equivalent to the order of magnitude of those extreme climatic events-induced refugees.The secondary geological hazards related to the earthquakes(e.g.,extensive landslides and soil erosion),which could last for decades,caused more casualties and reduced food production.Furthermore,great plague spread caused by the casualties could significantly increase psychological panic among the survivors,resulting in social instability.Therefore,catastrophic seismic events could also accelerate the collapse of the dynasties(e.g.,the Ming dynasty)without immediate mitigation measures.This study indicates that catastrophic seismic activities,as well as extreme climatic events,could have great effects on the social structures and thus on the Chinese dynasty alternation on decadal timescales,which highlights the far-reaching implications of geological hazard research.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
The global monsoon system,encompassing the Asian-Australian,African,and American monsoons,sustains two-thirds of the world’s population by regulating water resources and agriculture.Monsoon anomalies pose severe risk...The global monsoon system,encompassing the Asian-Australian,African,and American monsoons,sustains two-thirds of the world’s population by regulating water resources and agriculture.Monsoon anomalies pose severe risks,including floods and droughts.Recent research associated with the implementation of the Global Monsoons Model Intercomparison Project under the umbrella of CMIP6 has advanced our understanding of its historical variability and driving mechanisms.Observational data reveal a 20th-century shift:increased rainfall pre-1950s,followed by aridification and partial recovery post-1980s,driven by both internal variability(e.g.,Atlantic Multidecadal Oscillation)and external forcings(greenhouse gases,aerosols),while ENSO drives interannual variability through ocean-atmosphere interactions.Future projections under greenhouse forcing suggest long-term monsoon intensification,though regional disparities and model uncertainties persist.Models indicate robust trends but struggle to quantify extremes,where thermodynamic effects(warming-induced moisture rise)uniformly boost heavy rainfall,while dynamical shifts(circulation changes)create spatial heterogeneity.Volcanic eruptions and proposed solar radiation modification(SRM)further complicate predictions:tropical eruptions suppress monsoons,whereas high-latitude events alter cross-equatorial flows,highlighting unresolved feedbacks.The emergent constraint approach is booming in terms of correcting future projections and reducing uncertainty with respect to the global monsoons.Critical challenges remain.Model biases and sparse 20th-century observational data hinder accurate attribution.The interplay between natural variability and anthropogenic forcings,along with nonlinear extreme precipitation risks under warming,demands deeper mechanistic insights.Additionally,SRM’s regional impacts and hemispheric monsoon interactions require systematic evaluation.Addressing these gaps necessitates enhanced observational networks,refined climate models,and interdisciplinary efforts to disentangle multiscale drivers,ultimately improving resilience strategies for monsoon-dependent regions.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
Based on daily observation data in the Three Gorges Region(TGR)of the Yangtze River Basin and global reanalysis data,the authors analyzed the climate characteristics and associated temporal variations in the main mete...Based on daily observation data in the Three Gorges Region(TGR)of the Yangtze River Basin and global reanalysis data,the authors analyzed the climate characteristics and associated temporal variations in the main meteorological factors in 2021,as well as the year’s climatic events and meteorological disasters.The 2021 average temperature was 0.2℃above the 1991-2020 average and the 13 th-warmest year since 1961.Seasonally,winter and autumn were both warmer than usual.The annual mean precipitation was 12.8%above normal,and most regions experienced abundant rainfall throughout the year.The seasonal variation in precipitation was significant and the TGR had a wetter-than-normal spring and summer.The number of rainstorm days was higher than normal;the wind speed was above normal;and the relative humidity was higher than normal.In terms of rain acidity,2021 was tied with 2020 as the lowest since 1999.From mid-September to early October 2021,the TGR experienced exceptional high-temperature weather,which was driven by abnormal activity of mid-and high-latitude atmospheric circulation over the Eurasian continent and the western Pacific subtropical high(WPSH).In addition,a strong blocking high over the Ural Mountains accompanied by intense mid-latitude westerly winds prevented cyclonic disturbances from extending to the subtropical region.As a result,under the combined effect of the weaker-than-normal cold-air activities and the anomalous WPSH,the TGR experienced extreme high-temperature weather during early autumn 2021.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
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
Climate events pose major challenges to food production and the livelihoods of rural inhabitants in northern Laos, where upland rice using swidden production is an important crop. The onset of the rainy season in this...Climate events pose major challenges to food production and the livelihoods of rural inhabitants in northern Laos, where upland rice using swidden production is an important crop. The onset of the rainy season in this area is one such climate event, and it has occurred earlier and with less regularity in recent years. Not all households are able to cope with these changes. This study examines the ability of local farmers to cope with rice insufficiency. This investigation also clarifies household strategies in dealing with the climate event. We randomly interviewed 63 of 95 household heads, and performed a paired sample t test to examine the significance of differences in three household groups between the 2010 normal climate and the 2011 climate event. The groups were categorized according to rice selfsufficiency in 2011: groups I are households with rice self-sufficiency, group II are those facing a rice shortage of up to 3 months, and group III are those with insufficient rice for over 3 months. We also conducted a one-way ANOVA to examine the significance of differences in livelihood strategies among the three groups. We found that the household labor force was the most important factor in enhancing the villagers' ability to deal with the climate event and that the level of impact of that event shaped their coping strategies. Households with substantial labor force had more options for coping strategies than those with smaller ones. The villagers faced different levels of impact and adopted differentcoping strategies accordingly. Non-timber forest product collection was the principle livelihood strategy in response to non-climate factors such as education, access to health services, provision of equipment and clothing, and overcoming the impact of the climate event. Households heavily affected by the early rainy season onset tended to engage in intensive activities such as off-farm activity and outside work, rather than their major livelihood activities in the village(upland crop and livestock production).展开更多
Ecological stability is a core issue in ecological research and holds significant implications forhumanity. The increased frequency and intensity of drought and wet climate events resulting from climatechange pose a m...Ecological stability is a core issue in ecological research and holds significant implications forhumanity. The increased frequency and intensity of drought and wet climate events resulting from climatechange pose a major threat to global ecological stability. Variations in stability among different ecosystemshave been confirmed, but it remains unclear whether there are differences in stability within the sameterrestrial vegetation ecosystem under the influence of climate events in different directions and intensities.China's grassland ecosystem includes most grassland types and is a good choice for studying this issue.This study used the Standardized Precipitation Evapotranspiration Index-12 (SPEI-12) to identify thedirections and intensities of different types of climate events, and based on Normalized DifferenceVegetation Index (NDVI), calculated the resistance and resilience of different grassland types for 30consecutive years from 1990 to 2019 (resistance and resilience are important indicators to measurestability). Based on a traditional regression model, standardized methods were integrated to analyze theimpacts of the intensity and duration of drought and wet events on vegetation stability. The resultsshowed that meadow steppe exhibited the highest stability, while alpine steppe and desert steppe had thelowest overall stability. The stability of typical steppe, alpine meadow, temperate meadow was at anintermediate level. Regarding the impact of the duration and intensity of climate events on vegetationecosystem stability for the same grassland type, the resilience of desert steppe during drought was mainlyaffected by the duration. In contrast, the impact of intensity was not significant. However, alpine steppewas mainly affected by intensity in wet environments, and duration had no significant impact. Ourconclusions can provide decision support for the future grassland ecosystem governance.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
基金supported by the Second Scientific Expedition to the Qinghai‒Xizang Plateau(Grant No.2019QZKK0405-05)method-ological support from the State Key Program of the National Natural Science Foundation of China(Grant No.72033005)is also appreciated greatly.
文摘Global warming has led to the frequent occurrence of extreme climatic events(ECEs)in the ecologically frag ile Qinghai-Xizang Plateau.Rural households face strong barriers in adaption,and food production is seriously threatened.Current methods for increasing household adaptability take a holistic point of view,but do not ac curately identify groups experiencing different adaptive barriers.To better identify different barriers,this paper examines natural,economic,cognitive,and technical barriers.A total of 17 indicators were selected to com prehensively evaluate the degree of barriers to crops adaptation in response to ECEs.Key factors were further analyzed to identify paths to break down the barriers.The results showed the following.(1)Natural barriers were present at the highest degree,economic barriers appear to be smallest,and the overall barriers were bi ased towards the lower quartile.10.82%of the households with the highest barriers.(2)67.38%of households report taking adaptive measures in crops production.The increase of the barriers leads to an increase and then a decrease in the possibility of adaptive behavior.(3)Addressing technical barriers is key to rapidly increasing household adaptive behavior in response to ECEs.The study provides recommendations for local governments to improve household adaptation behavior from two perspectives:short-term and long-term optimization path ways.This study can help governments quickly locate households with different classes of barriers,and propose more targeted adaptation policies.The ultimate goal is to ensure the sustainability of crops production and the well-being of households in northeastern part of the Qinghai-Xizang Plateau.
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.
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the National Natural Science Foundation of China(Nos.41991323,41702185,41977378,U1706220)the National Key Basic Research Program of China(No.2015CB953804)+5 种基金the Na-tural Science Foundation of Shandong Province(No.ZR 2018PD005)the Jiangsu Provincial Basic Research Pro-gram Natural Science Foundation General Project of China(No.BK20171340)the Open Foundation of CAS Key La-boratory of Coastal Environmental Processes and Ecolo-gical Remediation,YICCAS(No.2020KFJJ10)the Open Foundation of State Key Laboratory of Loess and Quater-nary Geology,Institute of Earth Environment,CAS(No.SK LLQG2024)the Laboratory for Marine Geology,Qingdao National Laboratory for Marine Science and Technology(No.MGQNLM-KF201704)the Foundation of School and Land Integration Development in Yantai(No.2021 XDRHXMQT18).
文摘The inner shelf mud wedge(ISMW)located in the East China Sea(ECS)is the fine-grained sedimentary area with high sedimentation rate and has provided an ideal study area for understanding the East Asian Summer Monsoon(EASM)evolution during the Holocene.In this paper,we presented the high-resolution geochemical data of the sediments from the core MD06-3040 in the ISMW of the ECS determined by X-ray fluorescence core scanning(XRF-CS)analysis,a high-resolution,continuous,and multielement method.Geochemical and factor analysis results reveal that the variations of elemental compositions(Al,Si,K,Ti,Fe),the elemental ratios of Al/Zr,Ca/Ti and Rb/Sr,and the factor scores(F1 are correlated with the changes of the EASM during the period of 6000–1300 cal yr BP.The higher values of geochemical compositions indicating the terrigenous inputs implied the intensification of anthropogenic activities after 1300 cal yr BP.Meanwhile,the significant decrease of most geochemical compositions and the F1 factor scores during 4500–3500 cal yr BP and 1700–1500 cal yr BP,within the dating errors,coincided with the weak EASM events(presumably drought and cold events).The spectral analysis results of K concentrations,Al/Zr ratios and F1 factor scores show the millennial and centennial climatic fluctuations,which are consistent with other marine sedimentary records in the adjacent areas.All the findings show that the geochemical compositions of sediments from core MD06-3040 are influenced by the EASM evolution,the variable El Niño/Southern Oscillation(ENSO)and the local oceanic thermohaline circulation(e.g.,Kuroshio Current).These results are greatly helpful in uncovering the forcing mechanism of the monsoonal climate in the east China over the Holocene and also contribute to the understanding of EASM variability.
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 the National Natural Science Foundation of China(Nos.31971541 and 32201545).
文摘Extreme weather events pose an ever-greater threat to people,infrastructure,and nature.Forest ecosystems are highly sensitive to extreme cold events that can disrupt ecosystem functions,especially in montane regions.Ice storms can be particularly destructive,with rapid ice accretion causing tree branches to break,even snapping or uprooting entire trees.In March 2022,the Shennongjia forest in central China experienced severe ice storm conditions that severely damaged over 230,300ha.We utilized this opportunity to assess the vulnerability of different tree types(coniferous,deciduous,and evergreen broad-leaved)and stand compositions to damage resulting from ice glaze along an elevation gradient from 1,200 to 2,400m a.s.l.Among the 7,144 trees surveyed,10.1%suffered some extent of damage,which was most prolific in the middle elevation zone.While 96.8%of all damage occurred to deciduous broadleaved trees that dominated the forest community,the most severe damage(uprooting and lower trunk breakage)occurred to coniferous trees.The extent and severity of tree damage were moderated by forest composition,with secondary effects of forest structure and slope.Abiotic factors predominantly affected coniferous trees.We emphasize that more research and monitoring are needed to better understand the full impact of extreme weather events on forests,especially as the frequency and intensity of these events increases due to climate change.
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Sino-France Cooperation Foundation (PRA E02-07) The key project of CAS+3 种基金No.KZCX3-SW-331 National Natural Science Foundation of China No.40271112 Foundation of Key Laboratory of Flood and Waterlogging and Wet Land Agriculture of Hubei Province
文摘Wide collection on the historic records of the climatic changes and flood events is performed in the Yangtze Delta. Man-Kendall (MK) method is applied to explore the changing trends of the time series of the flood discharge and the maximum high summer temperature. The research results indicate that the flood magnitudes increased during the transition from the medieval warm interval into the early Little Ice Age. Fluctuating climate changes of the Little Ice Age characterized by arid climate events followed by the humid and cold climate conditions give rise to the frequent flood hazards. Low-lying terrain made the study region prone to the flood hazards, storm tide and typhoon. MK analysis reveals that the jumping point of the time series of the flood discharge changes occurred in the mid-1960s, that of the maximum summer temperature changes in the mid-1990s, and the exact jump point in 1993. The flood discharge changes are on negative trend before the 1990s, they are on positive tendency after the 1990s; the maximum high summer temperature changes are on negative trend before the 1990s and on positive tendency after the 1990s. These results indicate that the trend of flood discharge matches that of the maximum high summer temperature in the Yangtze Delta. The occurrence probability of the maximum high summer temperature will be increasing under the climatic warming scenario and which will in turn increase the occurrence probability of the flood events. More active solar action epochs and the higher sea surface temperature index (SST index) of the south Pacific Ocean area lying between 4 o N-4 o S and 150 o W-90 o W correspond to increased annual precipitation, flood discharge and occurrence frequency of floods in the Yangtze Delta. This is partly because the intensified solar activities and the higher SST index give rise to accelerated hydrological circulation from ocean surface to the continent, resulting in increased precipitation on the continent.
基金supported by the National Natural Science Foundation of China(Nos.42301029,42371354)the Scientific Research Start-up Fund for New Young Faculty,China University of Geosciences,Wuhan(No.CUGXQN2307)China Meteorological Administration Innovation and Development Project(No.CXFZ2023J051).
文摘Compound extreme climate events may profoundly affect human activity in the Yangtze River Basin.This study analyzed the long-term spatiotemporal distribution characteristics of compound heatwave-drought and heatwave-waterlogging events in the Yangtze River Basin using multi-period historical observation data and future scenario climate model data.It also examined the changes in population exposure to compound extreme climate events in the basin and their driving factors by combining population statistics and forecast data.The results show that the occurrence days of compound heatwave-drought and heatwave-waterlogging events in the Yangtze River Basin have shown a significant upward trend both in historical periods and future scenarios,accompanied by a marked expansion in the affected areas.Compared to historical periods,population exposure in the Yangtze River Basin under future scenarios is expected to increase by 1.5–2 times,primarily concentrated in the key urban areas of the basin.The main factors driving the changes in population exposure are the increased frequency of extreme climate events and population decline in future scenarios.These findings provide scientific evidence for early mitigation of meteorological disasters in the Yangtze River Basin.
基金supported by the National Natural Science Foundation of China (Grant Nos.42005029 and 41701103)the China Meteorological Administration Special Foundation for Innovation and Development (Grant No.CXFZ2024Q007)。
文摘In the summer of 2024, following a strong El Ni?o event in the preceding winter, the tropical Indian Ocean and tropical North Atlantic recorded their highest SSTs since 1961, along with a significant westward shift and intensification of the western Pacific subtropical high(WPSH). Under these conditions, China experienced its hottest summer since 1961,and was hit by a series of high-impact extreme weather and climate events. From 9 June to 2 July, southern China experienced an unprecedented extreme precipitation event that exceeded the well-known 1998 summer precipitation event in both duration and impact scope, resulting in devastating floods in the Yangtze River basin. Subsequently, in early to midJuly, the Huanghe-Huaihe Basin suffered from a severe drought–flood abrupt alternation event, heavily affecting Henan and Shandong. Meanwhile, southern China underwent a widespread heatwave event lasting 74 days, ranking as the second most intense since 1961. From late July to the end of August, northern China faced unusually frequent heavy precipitation events, with cumulative precipitation reaching the second highest for the same period since 1961, causing floods in many rivers of northern China. This study provides a timely summary and assessment of the characteristics and impacts of these extreme events. It serves as a reference for climate change research, including mechanism analysis, numerical simulation,and climate event attribution, and also offers valuable insights for improving meteorological disaster prevention and mitigation strategies.
基金National Nonprofit Fundamental Research Grant of China,Institute of Geology,China Earthquake Administration,No.IGCEA2009。
文摘General history of disasters in China suggests that China has frequently experienced two major natural disasters in its long history,one is from catastrophic earthquake events,and the other is from extreme climatic events,due to its unique active tectonic environment and climatic complexity.Although these two major natural disasters have caused great damage to human society,it remains unclear whether and how they affect Chinese dynasty alternation on decadal(emperor)timescales.Based on detailed comparisons between abrupt climatic changes,catastrophic seismic activities,and the history of Chinese dynasty alternation from 1000–2000 AD,we conclude that on decadal timescales,extreme drought(and/or flood)events could indeed significantly reduce agricultural production,cause severe food shortages and famine,and result in increases in population exile,rising food prices and inflation,and insufficient supplies for military defense,which could exceed social resilience and eventually lead to financial risks and social upheavals of the dynasties.In addition,catastrophic seismic events in the densely populated,agricultural areas of China,including the 1303 surface wave magnitude(M_(s))8.0 Hongtong earthquake,the 1556 M_(s)8.25Huaxian earthquake and the 1920 M_(s)8.5 Haiyuan earthquake,caused more than 200,000casualties and millions of victims to live in exile which was almost equivalent to the order of magnitude of those extreme climatic events-induced refugees.The secondary geological hazards related to the earthquakes(e.g.,extensive landslides and soil erosion),which could last for decades,caused more casualties and reduced food production.Furthermore,great plague spread caused by the casualties could significantly increase psychological panic among the survivors,resulting in social instability.Therefore,catastrophic seismic events could also accelerate the collapse of the dynasties(e.g.,the Ming dynasty)without immediate mitigation measures.This study indicates that catastrophic seismic activities,as well as extreme climatic events,could have great effects on the social structures and thus on the Chinese dynasty alternation on decadal timescales,which highlights the far-reaching implications of geological hazard research.
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supported by the National Key Research and Development Program of China(Grant No.2020YFA0608904)the International Partnership Program of the Chinese Academy of Sciences(Grant Nos.060GJHZ2023079GC and 134111KYSB20160031)+1 种基金supported by the Office of Science,U.S.Department of Energy(DOE)Biological and Environmental Research as part of the Regional and Global Model Analysis program area through the Water Cycle and Climate Extremes Modeling(WACCEM)scientific focus areaoperated for DOE by Battelle Memorial Institute under contract DE-AC05-76RL01830。
文摘The global monsoon system,encompassing the Asian-Australian,African,and American monsoons,sustains two-thirds of the world’s population by regulating water resources and agriculture.Monsoon anomalies pose severe risks,including floods and droughts.Recent research associated with the implementation of the Global Monsoons Model Intercomparison Project under the umbrella of CMIP6 has advanced our understanding of its historical variability and driving mechanisms.Observational data reveal a 20th-century shift:increased rainfall pre-1950s,followed by aridification and partial recovery post-1980s,driven by both internal variability(e.g.,Atlantic Multidecadal Oscillation)and external forcings(greenhouse gases,aerosols),while ENSO drives interannual variability through ocean-atmosphere interactions.Future projections under greenhouse forcing suggest long-term monsoon intensification,though regional disparities and model uncertainties persist.Models indicate robust trends but struggle to quantify extremes,where thermodynamic effects(warming-induced moisture rise)uniformly boost heavy rainfall,while dynamical shifts(circulation changes)create spatial heterogeneity.Volcanic eruptions and proposed solar radiation modification(SRM)further complicate predictions:tropical eruptions suppress monsoons,whereas high-latitude events alter cross-equatorial flows,highlighting unresolved feedbacks.The emergent constraint approach is booming in terms of correcting future projections and reducing uncertainty with respect to the global monsoons.Critical challenges remain.Model biases and sparse 20th-century observational data hinder accurate attribution.The interplay between natural variability and anthropogenic forcings,along with nonlinear extreme precipitation risks under warming,demands deeper mechanistic insights.Additionally,SRM’s regional impacts and hemispheric monsoon interactions require systematic evaluation.Addressing these gaps necessitates enhanced observational networks,refined climate models,and interdisciplinary efforts to disentangle multiscale drivers,ultimately improving resilience strategies for monsoon-dependent regions.
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jointly supported by the funds of the Strategic Cooperation Agreement Project between the China Meteorological Administration and the Three Gorges Corporation[Grant No.0704182]the Comprehensive Monitoring Program for Operational Safety of the Three Gorges Project[Grant No.SK2021015]financed by the Ministry of Water Resources of China.
文摘Based on daily observation data in the Three Gorges Region(TGR)of the Yangtze River Basin and global reanalysis data,the authors analyzed the climate characteristics and associated temporal variations in the main meteorological factors in 2021,as well as the year’s climatic events and meteorological disasters.The 2021 average temperature was 0.2℃above the 1991-2020 average and the 13 th-warmest year since 1961.Seasonally,winter and autumn were both warmer than usual.The annual mean precipitation was 12.8%above normal,and most regions experienced abundant rainfall throughout the year.The seasonal variation in precipitation was significant and the TGR had a wetter-than-normal spring and summer.The number of rainstorm days was higher than normal;the wind speed was above normal;and the relative humidity was higher than normal.In terms of rain acidity,2021 was tied with 2020 as the lowest since 1999.From mid-September to early October 2021,the TGR experienced exceptional high-temperature weather,which was driven by abnormal activity of mid-and high-latitude atmospheric circulation over the Eurasian continent and the western Pacific subtropical high(WPSH).In addition,a strong blocking high over the Ural Mountains accompanied by intense mid-latitude westerly winds prevented cyclonic disturbances from extending to the subtropical region.As a result,under the combined effect of the weaker-than-normal cold-air activities and the anomalous WPSH,the TGR experienced extreme high-temperature weather during early autumn 2021.
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.
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funded by Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research (Kakenhi), Scientific Research (A)
文摘Climate events pose major challenges to food production and the livelihoods of rural inhabitants in northern Laos, where upland rice using swidden production is an important crop. The onset of the rainy season in this area is one such climate event, and it has occurred earlier and with less regularity in recent years. Not all households are able to cope with these changes. This study examines the ability of local farmers to cope with rice insufficiency. This investigation also clarifies household strategies in dealing with the climate event. We randomly interviewed 63 of 95 household heads, and performed a paired sample t test to examine the significance of differences in three household groups between the 2010 normal climate and the 2011 climate event. The groups were categorized according to rice selfsufficiency in 2011: groups I are households with rice self-sufficiency, group II are those facing a rice shortage of up to 3 months, and group III are those with insufficient rice for over 3 months. We also conducted a one-way ANOVA to examine the significance of differences in livelihood strategies among the three groups. We found that the household labor force was the most important factor in enhancing the villagers' ability to deal with the climate event and that the level of impact of that event shaped their coping strategies. Households with substantial labor force had more options for coping strategies than those with smaller ones. The villagers faced different levels of impact and adopted differentcoping strategies accordingly. Non-timber forest product collection was the principle livelihood strategy in response to non-climate factors such as education, access to health services, provision of equipment and clothing, and overcoming the impact of the climate event. Households heavily affected by the early rainy season onset tended to engage in intensive activities such as off-farm activity and outside work, rather than their major livelihood activities in the village(upland crop and livestock production).
基金the National Natural Science Foundation of China(42271289).
文摘Ecological stability is a core issue in ecological research and holds significant implications forhumanity. The increased frequency and intensity of drought and wet climate events resulting from climatechange pose a major threat to global ecological stability. Variations in stability among different ecosystemshave been confirmed, but it remains unclear whether there are differences in stability within the sameterrestrial vegetation ecosystem under the influence of climate events in different directions and intensities.China's grassland ecosystem includes most grassland types and is a good choice for studying this issue.This study used the Standardized Precipitation Evapotranspiration Index-12 (SPEI-12) to identify thedirections and intensities of different types of climate events, and based on Normalized DifferenceVegetation Index (NDVI), calculated the resistance and resilience of different grassland types for 30consecutive years from 1990 to 2019 (resistance and resilience are important indicators to measurestability). Based on a traditional regression model, standardized methods were integrated to analyze theimpacts of the intensity and duration of drought and wet events on vegetation stability. The resultsshowed that meadow steppe exhibited the highest stability, while alpine steppe and desert steppe had thelowest overall stability. The stability of typical steppe, alpine meadow, temperate meadow was at anintermediate level. Regarding the impact of the duration and intensity of climate events on vegetationecosystem stability for the same grassland type, the resilience of desert steppe during drought was mainlyaffected by the duration. In contrast, the impact of intensity was not significant. However, alpine steppewas mainly affected by intensity in wet environments, and duration had no significant impact. Ourconclusions can provide decision support for the future grassland ecosystem governance.
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;
