Dear Editor,This letter addresses the impulse game problem for a general scope of deterministic,multi-player,nonzero-sum differential games wherein all participants adopt impulse controls.Our objective is to formulate...Dear Editor,This letter addresses the impulse game problem for a general scope of deterministic,multi-player,nonzero-sum differential games wherein all participants adopt impulse controls.Our objective is to formulate this impulse game problem with the modified objective function including interaction costs among the players in a discontinuous fashion,and subsequently,to derive a verification theorem for identifying the feedback Nash equilibrium strategy.展开更多
By using the observed monthly mean data over 160 stations of China and NCAR/NCEP reanalysis data, the generalized equilibrium feedback assessment(GEFA) method, combined with the methods of EOF analysis, correlation an...By using the observed monthly mean data over 160 stations of China and NCAR/NCEP reanalysis data, the generalized equilibrium feedback assessment(GEFA) method, combined with the methods of EOF analysis, correlation and composite analysis, is used to explore the influence of different SST modes on a wintertime air temperature pattern in which it is cold in the northeast and warm in the southwest in China. The results show that the 2009/2010 winter air temperature oscillation mode between the northern and southern part of China is closely related to the corresponding sea surface temperature anomalies(SSTA) and its associated atmospheric circulation anomalies. Exhibiting warming in Northeast China and cooling in Southwest China, the mode is significantly forced by the El Nio mode and the North Atlantic SSTA mode, which have three poles. Under the influence of SSTA modes, the surface northerly flow transported cold air to North and Northeast China, resulting in low temperatures in the regions. Meanwhile, the mid-latitude westerlies intensify and the polar cold air stays in high latitudes and cannot affect the Southwest China, resulting in the warming there.展开更多
Atmospheric response to SST variability was estimated using generalized equilibrium feedback analysis （GEFA） in the SST EOF space with synthesis data from an idealized climate model. Results show that the GEFA atmos...Atmospheric response to SST variability was estimated using generalized equilibrium feedback analysis （GEFA） in the SST EOF space with synthesis data from an idealized climate model. Results show that the GEFA atmospheric response to the leading SST EOF modes is much more accurate and robust than the GEFA feedback matrix in physical space. Therefore, GEFA provides a practical method for assessing atmospheric response to large-scale SST anomalies in terms of the leading EOFs.展开更多
Tanzania is mainly subject to a bimodal rainfall pattern,characterized by two distinct seasons:the long rains,occurring from March to May,and the short rains,which typically take place from October to December(OND).Sh...Tanzania is mainly subject to a bimodal rainfall pattern,characterized by two distinct seasons:the long rains,occurring from March to May,and the short rains,which typically take place from October to December(OND).Short rains are usually less intense but still significantly influence local agriculture.Therefore,with station-based observations and reanalysis data,the current paper examines the interannual variability of OND precipitation in Tanzania from 1993 to 2022 and explores the possible impacts from El Niño–Southern Oscillation(ENSO)and the Indian Ocean Dipole(IOD)as well as the mechanisms.It is found that the Tanzania OND precipitation is above(below)normal in 1997,2006,2011,and 2019(1993,1998,2005,and 2016).The composite difference between wet(dry)years and the climatology indicates that the anomalous lower-level convergence(divergence)and upward(downward)motion are the critical circulation characters for above(below)precipitation.Further analysis indicates ENSO and the IOD are the two main oceanic systems modulating OND precipitation in Tanzania.El Niño and a positive IOD could induce easterly anomalies and weaken the Walker circulation over the Indian Ocean,consequently leading to lower-level convergence in water vapor flux,upward anomalies,and more than normal precipitation in Tanzania.In contrast,La Niña and a negative IOD produce opposite circulation anomalies and less than normal precipitation over Tanzania.Moreover,through partial correlation and Generalized Equilibrium Feedback Analysis,the individual contributions of ENSO and the IOD to circulation are investigated.It is found that although both the IOD and ENSO impact the Walker circulation,the feedback to the IOD is stronger than ENSO.These results provide critical insights into the oceanic drivers and their mechanistic pathways underlying precipitation anomalies in Tanzania.展开更多
利用中国160个台站和NCEP再分析资料,引入综合分析气候反馈的统计方法——广义平衡反馈方法(GEFA),结合EOF、相关合成分析,探讨2009/2010年中国冬季气温异常型的成因。结果表明:2009/2010年中国冬季气温出现的东北冷西南暖分布型与同期...利用中国160个台站和NCEP再分析资料,引入综合分析气候反馈的统计方法——广义平衡反馈方法(GEFA),结合EOF、相关合成分析,探讨2009/2010年中国冬季气温异常型的成因。结果表明:2009/2010年中国冬季气温出现的东北冷西南暖分布型与同期海温异常及其相联系的大气环流异常有密切的关系。其中赤道中东太平洋海温异常的El Ni o型和赤道大西洋海温异常"正-负-正"三极型模态对2009/2010年中国冬季气温东北冷西南暖分布型有显著的强迫作用。上述海温异常型影响了大气环流异常,中高纬度地面偏北气流将冷空气输送到华北东北地区,致使该地区冬季气温偏低,同时中纬度西风增强,极地冷空气被迫盘踞在高纬,不能影响到西南地区,导致西南地区较常年更暖。展开更多
基金supported in part by the National Natural Science Foundation of China(62173051)the Fundamental Research Funds for the Central Universities(2024CDJCGJ012,2023CDJXY-010)+1 种基金the Chongqing Technology Innovation and Application Development Special Key Project(CSTB2022TIADCUX0015,CSTB2022TIAD-KPX0162)the China Postdoctoral Science Foundation(2024M763865)
文摘Dear Editor,This letter addresses the impulse game problem for a general scope of deterministic,multi-player,nonzero-sum differential games wherein all participants adopt impulse controls.Our objective is to formulate this impulse game problem with the modified objective function including interaction costs among the players in a discontinuous fashion,and subsequently,to derive a verification theorem for identifying the feedback Nash equilibrium strategy.
基金Specialized Science Project for Public Welfare Industries(Meteorology)(GYHY200906016)State Key Program of National Natural Science Foundation of China(41230528)
文摘By using the observed monthly mean data over 160 stations of China and NCAR/NCEP reanalysis data, the generalized equilibrium feedback assessment(GEFA) method, combined with the methods of EOF analysis, correlation and composite analysis, is used to explore the influence of different SST modes on a wintertime air temperature pattern in which it is cold in the northeast and warm in the southwest in China. The results show that the 2009/2010 winter air temperature oscillation mode between the northern and southern part of China is closely related to the corresponding sea surface temperature anomalies(SSTA) and its associated atmospheric circulation anomalies. Exhibiting warming in Northeast China and cooling in Southwest China, the mode is significantly forced by the El Nio mode and the North Atlantic SSTA mode, which have three poles. Under the influence of SSTA modes, the surface northerly flow transported cold air to North and Northeast China, resulting in low temperatures in the regions. Meanwhile, the mid-latitude westerlies intensify and the polar cold air stays in high latitudes and cannot affect the Southwest China, resulting in the warming there.
基金supported by National Natural Science Foundation of China 40830106the 111 Project of China (No. B07036)+1 种基金Ministry of Science and Technology of China (No. GYHY200906016)US Department of Environment (DOE 144 KQ65)
文摘Atmospheric response to SST variability was estimated using generalized equilibrium feedback analysis （GEFA） in the SST EOF space with synthesis data from an idealized climate model. Results show that the GEFA atmospheric response to the leading SST EOF modes is much more accurate and robust than the GEFA feedback matrix in physical space. Therefore, GEFA provides a practical method for assessing atmospheric response to large-scale SST anomalies in terms of the leading EOFs.
基金supported by the National Natural Science Foundation of China[grant numbers 42105030 and 42105066]the Ministry of Commerce,People’s Republic of China.
文摘Tanzania is mainly subject to a bimodal rainfall pattern,characterized by two distinct seasons:the long rains,occurring from March to May,and the short rains,which typically take place from October to December(OND).Short rains are usually less intense but still significantly influence local agriculture.Therefore,with station-based observations and reanalysis data,the current paper examines the interannual variability of OND precipitation in Tanzania from 1993 to 2022 and explores the possible impacts from El Niño–Southern Oscillation(ENSO)and the Indian Ocean Dipole(IOD)as well as the mechanisms.It is found that the Tanzania OND precipitation is above(below)normal in 1997,2006,2011,and 2019(1993,1998,2005,and 2016).The composite difference between wet(dry)years and the climatology indicates that the anomalous lower-level convergence(divergence)and upward(downward)motion are the critical circulation characters for above(below)precipitation.Further analysis indicates ENSO and the IOD are the two main oceanic systems modulating OND precipitation in Tanzania.El Niño and a positive IOD could induce easterly anomalies and weaken the Walker circulation over the Indian Ocean,consequently leading to lower-level convergence in water vapor flux,upward anomalies,and more than normal precipitation in Tanzania.In contrast,La Niña and a negative IOD produce opposite circulation anomalies and less than normal precipitation over Tanzania.Moreover,through partial correlation and Generalized Equilibrium Feedback Analysis,the individual contributions of ENSO and the IOD to circulation are investigated.It is found that although both the IOD and ENSO impact the Walker circulation,the feedback to the IOD is stronger than ENSO.These results provide critical insights into the oceanic drivers and their mechanistic pathways underlying precipitation anomalies in Tanzania.
文摘利用中国160个台站和NCEP再分析资料,引入综合分析气候反馈的统计方法——广义平衡反馈方法(GEFA),结合EOF、相关合成分析,探讨2009/2010年中国冬季气温异常型的成因。结果表明:2009/2010年中国冬季气温出现的东北冷西南暖分布型与同期海温异常及其相联系的大气环流异常有密切的关系。其中赤道中东太平洋海温异常的El Ni o型和赤道大西洋海温异常"正-负-正"三极型模态对2009/2010年中国冬季气温东北冷西南暖分布型有显著的强迫作用。上述海温异常型影响了大气环流异常,中高纬度地面偏北气流将冷空气输送到华北东北地区,致使该地区冬季气温偏低,同时中纬度西风增强,极地冷空气被迫盘踞在高纬,不能影响到西南地区,导致西南地区较常年更暖。
