A strong warm event happens during spring 1997 to spring 1999 in the South China Sea. Its intensity and duration show that it is the strongest event on the record over the past decades. It also corresponds with the se...A strong warm event happens during spring 1997 to spring 1999 in the South China Sea. Its intensity and duration show that it is the strongest event on the record over the past decades. It also corresponds with the severe flood over the valley of the Yangtze River and a couple of marine environmental events. This note addressed the evolution process by using several data sets, such as sea surface temperature, height and wind stress in addition to subsurface temperature. The onset of the warm event almost tele-connects with the El Nino event in the tropical Pacific Ocean. Summer monsoon is stronger and winter monsoon is weaker in 1997 so that there are persistent westerly anomalies in the South China Sea. During the development phase, the warm advection caused by southerly anomalies is the major factor while the adjustment of the thermocline is not obvious. Subsequently, the southerly anomalies decay and even northerly anomalies appear in the summer of 1998 resulting from the weaker than normal summer展开更多
By using the daily temperature data in 90 meteorological observatories in Shandong Province,the median and a new kind of extreme event detection method which was put forward by Hample,the variation characteristics of ...By using the daily temperature data in 90 meteorological observatories in Shandong Province,the median and a new kind of extreme event detection method which was put forward by Hample,the variation characteristics of extreme cold and warm weather climate events in Shandong Province were detected and analyzed.The results showed that the extreme high temperature days had no obvious variation,and the extreme warm days tended to increase.The extreme cold event decreased obviously and had the obvious inter-decadal variation characteristic.In the 1960s,the extreme cold(warm) event happened frequently,but they both decreased slightly during the 1970s-metaphase of 1980s.After the metaphase of 1990s,the extreme warm event happened frequently,but the extreme cold event decreased sharply.In the spatial distribution,the extreme cold events in most areas of Shandong tended to decrease.But the occurrence frequency variation of extreme warm event presented the radial distribution characteristics that it increased in the eastern coastal zone and decreased in the southwest,northwest of Shandong Province.Under the background that the global climate became warm obviously in the metaphase of 1980s,the positive trend scope of extreme warm event linear variation in Shandong Province obviously became large.The variation of extreme low temperature days in most areas tended to be stable,and the main trend of extreme cold days was still the rapid decrease.展开更多
Arctic amplification in the context of global warming has received considerable attention,and mechanisms such as ice-albedo feedback and extratropical cyclone activity have been proposed to explain such abnormal warmi...Arctic amplification in the context of global warming has received considerable attention,and mechanisms such as ice-albedo feedback and extratropical cyclone activity have been proposed to explain such abnormal warming.Since 2000,several short-term episodes of significant temperature rise have been observed in the Arctic;however,long-duration warming events in the central Arctic are less common and lack comprehensive research.Previous studies identified that amplified Rossbywaves could connect Arctic warming with extreme weather events in mid-latitude regions,and thus the recent increase in the frequency of mid-latitude extreme weather is also a subject of intensive research.With consideration of temperature anomalies,this study defined a continuous warming process as a warming event and selected strong warming events based on duration.Analysis of National Centers for Environmental Prediction Reanalysis-2 surface air temperature data found that nine strong warming events occurred during 2000-2019,which could be categorized into three types based on the area of warming.This study also investigated the relation between strong warming events and sea ice concentration reduction,sudden stratospheric warming,and extratropical cyclone activities.After full consideration and comparison,we believe that strong warming events in the central Arctic are induced primarily by continuous transport of warm air from mid-latitude ocean areas.展开更多
In this study, we explored spatial patterns and the temporal trends in high-temperature events （HTEs） for the mainland of China dudng 1961-2014 based on a dailymaximum surface-air-temperature dataset of 494 stations...In this study, we explored spatial patterns and the temporal trends in high-temperature events （HTEs） for the mainland of China dudng 1961-2014 based on a dailymaximum surface-air-temperature dataset of 494 stations and nonparametric trend detection methods. With three thresholds of 35℃ （HTE35）, 37℃ （HTE37）, and 40℃ （HTE40）, HTEs occurred in 82%, 71%, and 37% of the surveyed stations and showed an overall increasing trend in both frequency and intensity during 1961-2014. In northern and southeastem China, HTEs showed a significant increasing trend in both frequency and intensity, whilst a decreasing trend for both was observed in central China. Despite such regional heterogeneity, HTEs overwhelmingly presented three-phase characteristics in all three representative regions and throughout China; the phases are 1961-1980, 1980-1990, and 1990-2014. Both frequency and intensity of HTEs have strongly increased during 1990-2014 at 54.86%, 48.38%, and 23.28% of the investigated stations for HTE35, HTE37 and HTE40, respectively. These findings implied that HTEs adaptation should be paid further attention in the future over China because the wide spread distribution of HTEs and their increasing trends in both frequency and intensity during recent decades might pose challenges to the sustainability of human society and the ecosystem.展开更多
Based on the extreme climate index method issued by World Meteorological Organization,12 indices of Jiamusi during 1951-2010 were evaluated,and the extreme climate events and their variations were obtained. The result...Based on the extreme climate index method issued by World Meteorological Organization,12 indices of Jiamusi during 1951-2010 were evaluated,and the extreme climate events and their variations were obtained. The results showed that in recent 60 years,summer days( SU),extremely minimum temperature( TNN),extremely maximum temperature( TXX),warm nights( TN90) and warm days( TX90) displayed a significantly increasing tendency,while frost days( FD),cold nights( TN10) and cold days( TX10) showed a decreasing tendency. Changing trends of the all precipitation indices were not significant. The extremely low temperature events and extreme strong precipitation were related with El Nino.展开更多
基金This work was supported by the Knowledge Innovation Project of the Chinese Academy of Sciences (Grant No. KZCX2-205)the Ministry of Science and Technology (Grant Nos. G1999043806 and 2001DIA50041) National Natural Science Foundation of China (Grant N
文摘A strong warm event happens during spring 1997 to spring 1999 in the South China Sea. Its intensity and duration show that it is the strongest event on the record over the past decades. It also corresponds with the severe flood over the valley of the Yangtze River and a couple of marine environmental events. This note addressed the evolution process by using several data sets, such as sea surface temperature, height and wind stress in addition to subsurface temperature. The onset of the warm event almost tele-connects with the El Nino event in the tropical Pacific Ocean. Summer monsoon is stronger and winter monsoon is weaker in 1997 so that there are persistent westerly anomalies in the South China Sea. During the development phase, the warm advection caused by southerly anomalies is the major factor while the adjustment of the thermocline is not obvious. Subsequently, the southerly anomalies decay and even northerly anomalies appear in the summer of 1998 resulting from the weaker than normal summer
文摘By using the daily temperature data in 90 meteorological observatories in Shandong Province,the median and a new kind of extreme event detection method which was put forward by Hample,the variation characteristics of extreme cold and warm weather climate events in Shandong Province were detected and analyzed.The results showed that the extreme high temperature days had no obvious variation,and the extreme warm days tended to increase.The extreme cold event decreased obviously and had the obvious inter-decadal variation characteristic.In the 1960s,the extreme cold(warm) event happened frequently,but they both decreased slightly during the 1970s-metaphase of 1980s.After the metaphase of 1990s,the extreme warm event happened frequently,but the extreme cold event decreased sharply.In the spatial distribution,the extreme cold events in most areas of Shandong tended to decrease.But the occurrence frequency variation of extreme warm event presented the radial distribution characteristics that it increased in the eastern coastal zone and decreased in the southwest,northwest of Shandong Province.Under the background that the global climate became warm obviously in the metaphase of 1980s,the positive trend scope of extreme warm event linear variation in Shandong Province obviously became large.The variation of extreme low temperature days in most areas tended to be stable,and the main trend of extreme cold days was still the rapid decrease.
基金the Chinese Natural Science Foundation(Grant nos.,41941012 and 41976022)the Major Scientific and Technological Innovation Projects of Shandong Province(Grant no.,2018SDKJ0104-1)。
文摘Arctic amplification in the context of global warming has received considerable attention,and mechanisms such as ice-albedo feedback and extratropical cyclone activity have been proposed to explain such abnormal warming.Since 2000,several short-term episodes of significant temperature rise have been observed in the Arctic;however,long-duration warming events in the central Arctic are less common and lack comprehensive research.Previous studies identified that amplified Rossbywaves could connect Arctic warming with extreme weather events in mid-latitude regions,and thus the recent increase in the frequency of mid-latitude extreme weather is also a subject of intensive research.With consideration of temperature anomalies,this study defined a continuous warming process as a warming event and selected strong warming events based on duration.Analysis of National Centers for Environmental Prediction Reanalysis-2 surface air temperature data found that nine strong warming events occurred during 2000-2019,which could be categorized into three types based on the area of warming.This study also investigated the relation between strong warming events and sea ice concentration reduction,sudden stratospheric warming,and extratropical cyclone activities.After full consideration and comparison,we believe that strong warming events in the central Arctic are induced primarily by continuous transport of warm air from mid-latitude ocean areas.
基金National Natural Science Foundation of China, No.41401603
文摘In this study, we explored spatial patterns and the temporal trends in high-temperature events （HTEs） for the mainland of China dudng 1961-2014 based on a dailymaximum surface-air-temperature dataset of 494 stations and nonparametric trend detection methods. With three thresholds of 35℃ （HTE35）, 37℃ （HTE37）, and 40℃ （HTE40）, HTEs occurred in 82%, 71%, and 37% of the surveyed stations and showed an overall increasing trend in both frequency and intensity during 1961-2014. In northern and southeastem China, HTEs showed a significant increasing trend in both frequency and intensity, whilst a decreasing trend for both was observed in central China. Despite such regional heterogeneity, HTEs overwhelmingly presented three-phase characteristics in all three representative regions and throughout China; the phases are 1961-1980, 1980-1990, and 1990-2014. Both frequency and intensity of HTEs have strongly increased during 1990-2014 at 54.86%, 48.38%, and 23.28% of the investigated stations for HTE35, HTE37 and HTE40, respectively. These findings implied that HTEs adaptation should be paid further attention in the future over China because the wide spread distribution of HTEs and their increasing trends in both frequency and intensity during recent decades might pose challenges to the sustainability of human society and the ecosystem.
文摘Based on the extreme climate index method issued by World Meteorological Organization,12 indices of Jiamusi during 1951-2010 were evaluated,and the extreme climate events and their variations were obtained. The results showed that in recent 60 years,summer days( SU),extremely minimum temperature( TNN),extremely maximum temperature( TXX),warm nights( TN90) and warm days( TX90) displayed a significantly increasing tendency,while frost days( FD),cold nights( TN10) and cold days( TX10) showed a decreasing tendency. Changing trends of the all precipitation indices were not significant. The extremely low temperature events and extreme strong precipitation were related with El Nino.
基金国家自然科学基金资助项目“The magnitude and frequency of extreme late Holocene flooding in the middle Yangtze River and their climatic and anthropogenic forcing”(42250610211),“黄河下游地区中晚全新世重大洪泛事件及其对我国早期文明的影响”(41971102)江苏师范大学研究生科研与实践创新计划项目“1500AD以来江汉平原湖泊沉积物碳埋藏及其影响因素分析”(2024XKT0141)。
