Kangbao County is located in the northwest of Bashang in Hebei Province,which is a sub-arid area in the middle temperate zone,with a cold and arid climate and frequent disastrous weather.The meteorological data of Kan...Kangbao County is located in the northwest of Bashang in Hebei Province,which is a sub-arid area in the middle temperate zone,with a cold and arid climate and frequent disastrous weather.The meteorological data of Kangbao County Meteorological Station from 1994 to 2023 were selected,and the meteorological elements such as air pressure,temperature,precipitation,wind,relative humidity,sunshine,thunderstorm,hail,gale,rainstorm,fog,and snow cover were counted.The climate background analysis and high-impact weather analysis were carried out in combination with the topographic characteristics,geographical location,and climate characteristics.The results of meteorological sensitivity survey in the park showed that industries such as food,agriculture and new energy are very sensitive to temperature.During the visit to the enterprises in the park,it was found that heavy precipitation,snow,strong winds and hail had a great impact on many industries,and it was recommended to carry out long-term planning and reasonable design of buildings.It should pay close attention to forecasts and early warnings,formulate emergency plans for high-impact weather defense,and actively take preventive measures.展开更多
Seasonal variations of the tropical intraseasonal oscillation （ISO） and relationship to seasonal variation of the climate background are studied by using NCEP/NCAR reanalysis data and output of SAMIL-R42L9. Analysis...Seasonal variations of the tropical intraseasonal oscillation （ISO） and relationship to seasonal variation of the climate background are studied by using NCEP/NCAR reanalysis data and output of SAMIL-R42L9. Analysis of NCEP data shows that spatial distribution of the tropical ISO has obvious seasonal variations, which are well consistent with the seasonal variation of climate background. The activity of the tropical ISO is, to a great extent, dependent on warm SST, strong convection, zonal western wind, strong precipitation and low-level moisture convergence. Main characteristics of the seasonal variations of the tropical ISO are captured by SAMIL-R42L9. Simulations of seasonal variation of climate background vary greatly with different variables. Results of SAMIL-R42L9 indicate that the seasonal variations of the tropical ISO in dynamical fields are more dependent on climate background than in heating fields and SAMIL-R42L9 canllot represent well the strong dependence of the ISO on the climate background present in NCEP/NCAR reanalysis data. It also suggests that seasonal variations of the ISO do not completely depend on that of climate background.展开更多
The total 15 severe droughts are discovered with the aid of the 'RetrievalSystem of Chinese Historical Climate Records' for the last 1000 years. The droughts are extensive toenvelope more than 4 provinces and ...The total 15 severe droughts are discovered with the aid of the 'RetrievalSystem of Chinese Historical Climate Records' for the last 1000 years. The droughts are extensive toenvelope more than 4 provinces and persistent to cover 3 yr or more, and their severity isequivalent to or in excess of that in the 1930s in China. According to the documentary records andrestorations it can be inferred that most droughts are more severe than those in the last 50 years.The 15 droughts may either occur warm or in a cold climate background, with 11 of the 15 cases inthe cold phase. This indicates the difference in climate correspondence between China and northernAmerica, showing the severity of the events in China to be in a cold instead of a warm climatesituation. That is likely to relate to the monsoon climate in eastern Asia.展开更多
The Xinzhai Period (35503400 aBP) belongs to Late Neolithic Culture, which bridges the Longshan Culture and the Xia Culture in the Central Plains of China. By studying the living environment of ancient human beings at...The Xinzhai Period (35503400 aBP) belongs to Late Neolithic Culture, which bridges the Longshan Culture and the Xia Culture in the Central Plains of China. By studying the living environment of ancient human beings at the Xinzhai site, Henan Province, this paper pre-sents the discovery of extreme floods which threatened and destroyed the living environment of the ancient human beings during the Xinzhai Period. Pollen analysis and carbon-oxygen isotope measurement suggest that the climate was warm and wet during the Xinzhai Period, in contrast to the warm and arid climate during the Longshan Culture Period. The frequent flood events were the response of abrupt climate change during the Xinzhai Period. The conclusions drawn from this study not only help better understand the environmental change in the Central Plains of China around 3500 aBP, but also provide important clues to the environmental background for the origin of Chinese civilization.展开更多
Rivers originating from the Tibetan Plateau(TP)provide water to almost one-fifth of the global population[1,2].Due to its high elevation,the TP features high dependence on cryospheric meltwater,including meltwater fro...Rivers originating from the Tibetan Plateau(TP)provide water to almost one-fifth of the global population[1,2].Due to its high elevation,the TP features high dependence on cryospheric meltwater,including meltwater from snow,glaciers,and ground ice[3].In a warming climate,the sustainability of cryospheric meltwater on the TP has raised concerns because of its importance for the fragile ecosystems in the headwater regions.Existing studies mainly focused on glacier melt and snow melt on the TP[1,4,5],while the hydrological implications of thawing permafrost remain elusive.The TP has the world’s largest area of elevational permafrost,which features long-term preservation of ground ice that has formed since the Late Pleistocene[6].With ongoing climate warming,a large quantity of ground ice is likely to be mobilized and the meltwater could contribute to river runoff(Q)[7],which might also transport sediment and organic carbon fluxes[2].Existing large-scale hydrological modelling studies on the TP rarely include permafrost dynamics in their models[8,9].Therefore,the fate of ground ice and its hydrological implications across the entire TP remain largely unknown.展开更多
The surface wetness index,Palmer drought sererity index and the retrieval of soil moisture over China were calculated using monthly precipitation and monthly mean surface air temperature.Based on the contrast analysis...The surface wetness index,Palmer drought sererity index and the retrieval of soil moisture over China were calculated using monthly precipitation and monthly mean surface air temperature.Based on the contrast analysis of the variation of the above three indices and precipitation,the dry/wet spatio-temporal pattern of northern China in the last 54 years was revealed,and the evidence of drying trend over northern China was analyzed,especially.The results show the following four facts:(1)The drying trend is the main characteristic of the eastern part of Northwest China and the central part of North China since the 1980s and it was enhanced in the last 15 years mainly due to the precipitation decrease and the temperature increase;(2)During the last 54 years,there was only one dry/wet shift at the interdecadal scale occurring in the eastern part of Northwest China and the central part of North China in the late 1970s,which was related to 1977/1978 global abrupt change,whereas there were three shifts in Northeast China,one was in the mid 1990s and the other two were in 1965 and 1983,respectively;(3)Unlike the variation trend of other subregions of northern China,the western part of Northwest China is currently located in a relatively wetting period,which is weak-ened due to the temperature increase;(4)The extreme drought frequency is obviously increasing in the eastern part of Northwest China,the central part of North China and Northeast China since the 1980s,which is closely related to the precipitation decrease and temperature increase in these subregions.展开更多
文摘Kangbao County is located in the northwest of Bashang in Hebei Province,which is a sub-arid area in the middle temperate zone,with a cold and arid climate and frequent disastrous weather.The meteorological data of Kangbao County Meteorological Station from 1994 to 2023 were selected,and the meteorological elements such as air pressure,temperature,precipitation,wind,relative humidity,sunshine,thunderstorm,hail,gale,rainstorm,fog,and snow cover were counted.The climate background analysis and high-impact weather analysis were carried out in combination with the topographic characteristics,geographical location,and climate characteristics.The results of meteorological sensitivity survey in the park showed that industries such as food,agriculture and new energy are very sensitive to temperature.During the visit to the enterprises in the park,it was found that heavy precipitation,snow,strong winds and hail had a great impact on many industries,and it was recommended to carry out long-term planning and reasonable design of buildings.It should pay close attention to forecasts and early warnings,formulate emergency plans for high-impact weather defense,and actively take preventive measures.
基金Natural Science Foundation of China (4057502740675051)Innovative Project for ChineseAcademy of Sciences (KZCX3-sw-226)
文摘Seasonal variations of the tropical intraseasonal oscillation （ISO） and relationship to seasonal variation of the climate background are studied by using NCEP/NCAR reanalysis data and output of SAMIL-R42L9. Analysis of NCEP data shows that spatial distribution of the tropical ISO has obvious seasonal variations, which are well consistent with the seasonal variation of climate background. The activity of the tropical ISO is, to a great extent, dependent on warm SST, strong convection, zonal western wind, strong precipitation and low-level moisture convergence. Main characteristics of the seasonal variations of the tropical ISO are captured by SAMIL-R42L9. Simulations of seasonal variation of climate background vary greatly with different variables. Results of SAMIL-R42L9 indicate that the seasonal variations of the tropical ISO in dynamical fields are more dependent on climate background than in heating fields and SAMIL-R42L9 canllot represent well the strong dependence of the ISO on the climate background present in NCEP/NCAR reanalysis data. It also suggests that seasonal variations of the ISO do not completely depend on that of climate background.
基金Supported by the Project (No. 2001BA611B-01) from the Ministry of Science and Technology of China.
文摘The total 15 severe droughts are discovered with the aid of the 'RetrievalSystem of Chinese Historical Climate Records' for the last 1000 years. The droughts are extensive toenvelope more than 4 provinces and persistent to cover 3 yr or more, and their severity isequivalent to or in excess of that in the 1930s in China. According to the documentary records andrestorations it can be inferred that most droughts are more severe than those in the last 50 years.The 15 droughts may either occur warm or in a cold climate background, with 11 of the 15 cases inthe cold phase. This indicates the difference in climate correspondence between China and northernAmerica, showing the severity of the events in China to be in a cold instead of a warm climatesituation. That is likely to relate to the monsoon climate in eastern Asia.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 40171096) the Ministry of Science and Technology of China (Grant No. 2001BA805B05).
文摘The Xinzhai Period (35503400 aBP) belongs to Late Neolithic Culture, which bridges the Longshan Culture and the Xia Culture in the Central Plains of China. By studying the living environment of ancient human beings at the Xinzhai site, Henan Province, this paper pre-sents the discovery of extreme floods which threatened and destroyed the living environment of the ancient human beings during the Xinzhai Period. Pollen analysis and carbon-oxygen isotope measurement suggest that the climate was warm and wet during the Xinzhai Period, in contrast to the warm and arid climate during the Longshan Culture Period. The frequent flood events were the response of abrupt climate change during the Xinzhai Period. The conclusions drawn from this study not only help better understand the environmental change in the Central Plains of China around 3500 aBP, but also provide important clues to the environmental background for the origin of Chinese civilization.
基金the National Natural Science Foundation of China(42041004 and 52209027)the Strategic Priority Research Program of Chinese Academy of Sciences(XDA20100103)+3 种基金the support from the China Postdoctoral Science Foundation(2022M711857)the Postdoctoral Innovation Talents Support Program of China(BX2021166)the Shuimu Tsinghua Scholar Programthe financial support from the National Natural Science Foundation of China(42071029)。
文摘Rivers originating from the Tibetan Plateau(TP)provide water to almost one-fifth of the global population[1,2].Due to its high elevation,the TP features high dependence on cryospheric meltwater,including meltwater from snow,glaciers,and ground ice[3].In a warming climate,the sustainability of cryospheric meltwater on the TP has raised concerns because of its importance for the fragile ecosystems in the headwater regions.Existing studies mainly focused on glacier melt and snow melt on the TP[1,4,5],while the hydrological implications of thawing permafrost remain elusive.The TP has the world’s largest area of elevational permafrost,which features long-term preservation of ground ice that has formed since the Late Pleistocene[6].With ongoing climate warming,a large quantity of ground ice is likely to be mobilized and the meltwater could contribute to river runoff(Q)[7],which might also transport sediment and organic carbon fluxes[2].Existing large-scale hydrological modelling studies on the TP rarely include permafrost dynamics in their models[8,9].Therefore,the fate of ground ice and its hydrological implications across the entire TP remain largely unknown.
基金Thanks are given to two anonymous reviewers.This study is supported by the State Key Basic Development Planning Project(Grant No.2006CB400504)the Innovation Project of Chinese Academy of Sciences(Grant No.KZCX3-SW-229)the National Natural Science Foundation of China(Grant No.40375028).
文摘The surface wetness index,Palmer drought sererity index and the retrieval of soil moisture over China were calculated using monthly precipitation and monthly mean surface air temperature.Based on the contrast analysis of the variation of the above three indices and precipitation,the dry/wet spatio-temporal pattern of northern China in the last 54 years was revealed,and the evidence of drying trend over northern China was analyzed,especially.The results show the following four facts:(1)The drying trend is the main characteristic of the eastern part of Northwest China and the central part of North China since the 1980s and it was enhanced in the last 15 years mainly due to the precipitation decrease and the temperature increase;(2)During the last 54 years,there was only one dry/wet shift at the interdecadal scale occurring in the eastern part of Northwest China and the central part of North China in the late 1970s,which was related to 1977/1978 global abrupt change,whereas there were three shifts in Northeast China,one was in the mid 1990s and the other two were in 1965 and 1983,respectively;(3)Unlike the variation trend of other subregions of northern China,the western part of Northwest China is currently located in a relatively wetting period,which is weak-ened due to the temperature increase;(4)The extreme drought frequency is obviously increasing in the eastern part of Northwest China,the central part of North China and Northeast China since the 1980s,which is closely related to the precipitation decrease and temperature increase in these subregions.
