In this study, the authors simulate the East Asian climate changes in the mid-Pliocene (～3.3 to 3.0 Ma BP) with the Community Atmosphere Model version 3.1 (CAM3.1) and compare the simulated East Asian monsoon with pa...In this study, the authors simulate the East Asian climate changes in the mid-Pliocene (～3.3 to 3.0 Ma BP) with the Community Atmosphere Model version 3.1 (CAM3.1) and compare the simulated East Asian monsoon with paleoclimate data. The simulations show an obvious warming pattern in East Asia in the mid-Pliocene compared with the pre-industrial climate, with surface air temperature increasing by 0.5 4.0°C. In the warm mid-Pliocene simulation, the East Asian Summer Monsoon (EASM) becomes stronger, while the East Asian Winter Monsoon (EAWM) is similar relative to the pre-industrial climate. Compared with the paleoclimate data, our simulations depict the intensified EASM well but cannot reproduce the weakened EAWM. This model-data discrepancy may be attributed to the uncertainty in the reconstructed mid-Pliocene sea surface temperature.展开更多
Over the past 100 years, worldwide surface temperatures have increased at an unprecedented rate, contributing to warming of the oceans, melting ice fields and glaciers, and other adverse climatic effects. Southeast Fl...Over the past 100 years, worldwide surface temperatures have increased at an unprecedented rate, contributing to warming of the oceans, melting ice fields and glaciers, and other adverse climatic effects. Southeast Florida＇s vulnerability derives from its geographic location, low elevation, porous geology, unusual ground and surface water hydrology, subtropical weather patterns, and proximity to the Atlantic Ocean. The region is especially susceptible to sea level rise. After several millennia of stable sea levels prior to the 20th century, sea levels have been rising at accelerating rates due to thermal expansion of the oceans and from land-based ice melt The Everglades ecosystem and the water supplies for southeast Florida are particularly vulnerable as neither can be protected without significant expenditures of public dollars, and even these efforts may not prove to be successful. New approaches may be required to improve the resilience and prolong the sustainability of the region＇s water resources and ecosystem. The efforts to adapt to sea level changes in both the urban area and ecosystem as outlined herein are date and incident based-climate changes may occur earlier or later so instead of spending limited public dollars early, expenditures can be adjusted given future information.展开更多
During recent decades, more frequent flood-drought alternations have been seen in China as a result of global climate change and intensive human activities, which have sig- nificant implications on water and food secu...During recent decades, more frequent flood-drought alternations have been seen in China as a result of global climate change and intensive human activities, which have sig- nificant implications on water and food security. To better identify the characteristics of flood-drought alternations, we proposed a modified dry-wet abrupt alternation index （DWAAI） and applied the new method in the middle and lower reaches of the Yangtze River Basin （YRB-ML） to analyze the long-term spatio-temporal characteristics of dry-wet abrupt alterna- tion （DWAA） events based on the daily precipitation observations at 75 rainfall stations in summer from 1960 to 2015. We found that the DWAA events have been spreading in the study area with higher frequency and intensity since 1960. In particular, the DWAA events mainly occurred in May and June in the northwest of the YRB-ML, including Hanjiang River Basin, the middle reaches of the YRB, north of Dongting Lake and northwest of Poyang Lake. In addition, we also analyzed the impact of El Nifio Southern Oscillation （ENSO） on DWAA events in the YRB-ML. The results showed that around 41.04% of DWAA events occurred during the declining stages of La Nifia or within the subsequent 8 months after La Nina, which implies that La Nina events could be predictive signals of DWAA events. Besides, significant negative correlations have been found between the modified DWAAI values of all the rainfall stations and the sea surface temperature anomalies in the Nino3.4 region within the 6 months prior to the DWAA events, particularly for the Poyang Lake watershed and the middle reaches of the YRB. This study has significant implications on the flood and drought control and water resources management in the YRB-ML under the challenge of future climate change.展开更多
基金supported by the National Basic Research Program of China(2009CB421406)the Knowledge Innovation Program of the Chinese Academy of Sciences(KZCX2-YW-Q1-02)the National Natural Science Foundation of China(4090205 and 40975050)
文摘In this study, the authors simulate the East Asian climate changes in the mid-Pliocene (～3.3 to 3.0 Ma BP) with the Community Atmosphere Model version 3.1 (CAM3.1) and compare the simulated East Asian monsoon with paleoclimate data. The simulations show an obvious warming pattern in East Asia in the mid-Pliocene compared with the pre-industrial climate, with surface air temperature increasing by 0.5 4.0°C. In the warm mid-Pliocene simulation, the East Asian Summer Monsoon (EASM) becomes stronger, while the East Asian Winter Monsoon (EAWM) is similar relative to the pre-industrial climate. Compared with the paleoclimate data, our simulations depict the intensified EASM well but cannot reproduce the weakened EAWM. This model-data discrepancy may be attributed to the uncertainty in the reconstructed mid-Pliocene sea surface temperature.
文摘Over the past 100 years, worldwide surface temperatures have increased at an unprecedented rate, contributing to warming of the oceans, melting ice fields and glaciers, and other adverse climatic effects. Southeast Florida＇s vulnerability derives from its geographic location, low elevation, porous geology, unusual ground and surface water hydrology, subtropical weather patterns, and proximity to the Atlantic Ocean. The region is especially susceptible to sea level rise. After several millennia of stable sea levels prior to the 20th century, sea levels have been rising at accelerating rates due to thermal expansion of the oceans and from land-based ice melt The Everglades ecosystem and the water supplies for southeast Florida are particularly vulnerable as neither can be protected without significant expenditures of public dollars, and even these efforts may not prove to be successful. New approaches may be required to improve the resilience and prolong the sustainability of the region＇s water resources and ecosystem. The efforts to adapt to sea level changes in both the urban area and ecosystem as outlined herein are date and incident based-climate changes may occur earlier or later so instead of spending limited public dollars early, expenditures can be adjusted given future information.
基金National Key Research and Development Program in China,No.2017YFA0603704National Natural Science Foundation of China,No.51339004
文摘During recent decades, more frequent flood-drought alternations have been seen in China as a result of global climate change and intensive human activities, which have sig- nificant implications on water and food security. To better identify the characteristics of flood-drought alternations, we proposed a modified dry-wet abrupt alternation index （DWAAI） and applied the new method in the middle and lower reaches of the Yangtze River Basin （YRB-ML） to analyze the long-term spatio-temporal characteristics of dry-wet abrupt alterna- tion （DWAA） events based on the daily precipitation observations at 75 rainfall stations in summer from 1960 to 2015. We found that the DWAA events have been spreading in the study area with higher frequency and intensity since 1960. In particular, the DWAA events mainly occurred in May and June in the northwest of the YRB-ML, including Hanjiang River Basin, the middle reaches of the YRB, north of Dongting Lake and northwest of Poyang Lake. In addition, we also analyzed the impact of El Nifio Southern Oscillation （ENSO） on DWAA events in the YRB-ML. The results showed that around 41.04% of DWAA events occurred during the declining stages of La Nifia or within the subsequent 8 months after La Nina, which implies that La Nina events could be predictive signals of DWAA events. Besides, significant negative correlations have been found between the modified DWAAI values of all the rainfall stations and the sea surface temperature anomalies in the Nino3.4 region within the 6 months prior to the DWAA events, particularly for the Poyang Lake watershed and the middle reaches of the YRB. This study has significant implications on the flood and drought control and water resources management in the YRB-ML under the challenge of future climate change.
