过去的研究表明北大西洋多年代际变化(AMV)对南亚夏季风(SASM)有显著的影响。为进一步研究热带和中高纬北大西洋海温多年代际变化(AMV_Trop和AMV_SPG)对SASM的影响是否存在差异,本文基于地球系统模式(CESM)的大集合数据集(CESM-LE) 180...过去的研究表明北大西洋多年代际变化(AMV)对南亚夏季风(SASM)有显著的影响。为进一步研究热带和中高纬北大西洋海温多年代际变化(AMV_Trop和AMV_SPG)对SASM的影响是否存在差异,本文基于地球系统模式(CESM)的大集合数据集(CESM-LE) 1800年的工业革命前参照试验(PiControl)和1920~2005年的42组成员的历史试验(Historical)数据集,通过与观测和再分析资料进行对比,对模式模拟的不同区域AMV、SASM进行了评估,以及对不同区域AMV与SASM之间的联系进行了对比分析,结果显示:1) CESM模式能较好地模拟出观测AMV在热带和热带外区域的主要时空特征,以及SASM区域降水和大气环流的基本特征。2) 在观测结果中,不同区域的正位相AMV均对应于南亚中部区域降水的增加和温度的降低,北部区域降水的减少和温度的升高。3) 在工业革命前参照试验中,AMV、AMV_SPG在正位相时,对应于南亚区域南端降水的增加和北部区域不显著的降水减少,温度变化在AMV正位相时偏暖,在AMV_SPG中表现出大面积偏冷异常;正位相AMV_Trop对应于南亚地区降水的减少和温度的升高。4) 42组历史试验的平均结果与观测相反,不同区域的正位相AMV均对应于南亚地区降水减少。但是,42组试验中有30组表现与观测一致的变化,有12组表现出相反的变化。这表明AMV与SASM的联系具有不稳定性。Past studies have shown that the North Atlantic multiyear intergenerational variability (AMV) has a significant effect on the South Asian summer monsoon (SASM). To further investigate whether there is a difference in the effect of multi-year intergenerational variability of SST (AMV_Trop and AMV_SPG) on SASM between the tropical and mid- to high-latitude North Atlantic, this paper is based on the large ensemble dataset of the Center for Earth System Modeling (CESM) (CESM-LE) Pre-Industrial Revolutionary Reference Experiment (PiControl) of 1800 and the 1920~2005 42 The CESM large ensemble dataset (CESM-LE) 1800 pre-Industrial Revolution Reference Experiment (PiControl) and the Historical Experiment (Historical) dataset from 1920 to 2005 of 42 members of the PiControl group were used to evaluate the model-simulated AMVs and SASMs in different regions by comparing them with the observations and reanalyses as well as to compare and analyze the linkages between AMVs and SASMs in different regions. The results show that: 1) CESM model can simulate the main spatial and temporal characteristics of AMV in tropical and subpolar regions, as well as the basic characteristics of precipitation and atmospheric circulation in SASM region. 2) In the observations, the positive-phase AMV in different regions corresponds to an increase in precipitation and decrease in temperature in the central region of South Asia, and a decrease in precipitation and increase in temperature in the northern region. 3) In the pre-industrial revolution reference experiments, AMV and AMV_SPG in ortho-phase corresponded to an increase in precipitation in the southern end of the South Asian region and a non-significant decrease in precipitation in the northern region, and the temperature change was warm in the ortho-phase of AMV and exhibits large cold-biased anomalies in AMV_SPG;the ortho-phase AMV_Trop corresponded to a decrease in precipitation and an increase in temperature in the South Asian region. 4) The average results of the 42 sets of historical experiments are contrary to the observations, and the ortho-phase AMV in different regions corresponds to a decrease in precipitation in South Asia. However, 30 of the 42 sets of experiments show variations consistent with observations, and 12 sets show opposite variations. This suggests instability in the linkage between AMV and SASM.展开更多
文章利用中国气象局发布的热带气旋(TC)最佳路径数据资料,以及NCEP/NCAR大气再分析数据,分析了盛季(7~9月份)、后季(10~11月份)西北太平洋(WNP)TC累积气旋能量(ACE)与ENSO事件相关性的年代际变化。发现WNP TC盛季ACE与ENSO的相关性在198...文章利用中国气象局发布的热带气旋(TC)最佳路径数据资料,以及NCEP/NCAR大气再分析数据,分析了盛季(7~9月份)、后季(10~11月份)西北太平洋(WNP)TC累积气旋能量(ACE)与ENSO事件相关性的年代际变化。发现WNP TC盛季ACE与ENSO的相关性在1980年发生了年代际的突变,二者相关性由不显著变为显著的正相关。TC后季ACE与ENSO的相关性在1990年前后发生了年代际的突变,相关性由不相关变为显著的正相关。盛季、后季二者相关性年代际转变发生的事件不同,影响机制也不同。盛季ACE与ENSO相关性发生转变的主要原因是连续型ENSO在1980年之前发生频次较高,减弱了ENSO对ACE的影响。后季ACE与ENSO相关性发生转变的原因主要是1990年之前,El Niño多为东太平洋型,在WNP激发的环流异常为偶极子型分布,不能影响ACE的总量,1990年之后,El Niño发生时异常对流的位置偏西,WNP大部分区域被气旋式异常环流控制,有利于TC的生成和加强,因此TC ACE与ENSO有较好的相关性。This paper utilizes the best track data of tropical cyclones from the China Meteorological Administration, along with NCEP/NCAR reanalysis atmospheric data, to analyze the decadal shift in the relationship between the Accumulated Cyclone Energy (ACE) of tropical cyclones (TC) in the Northwest Pacific (WNP) during the peak (July-September) and late (October-November) seasons and ENSO events. It was found that the correlation between WNP TC ACE during the peak season and ENSO underwent a decadal shift in 1980, changing from non-significant to a significant positive correlation. The correlation between late-season TC ACE and ENSO also experienced a decadal shift around 1990, changing from no correlation to a significant positive correlation. The decadal shifts in correlation during the peak and late seasons occurred at different times and were driven by different mechanisms. The shift in the correlation between peak season TC ACE and ENSO is primarily due to the high frequency of continuous-type ENSO events before 1980, which weakened the influence of ENSO on ACE. The reason for the shift in the correlation between late-season TC ACE and ENSO is mainly because before 1990, El Niño was predominantly of the Eastern Pacific type, and the circulation anomalies it triggered in the WNP were of a dipole distribution, which did not affect the total ACE. After 1990, the position of anomalous convection during El Niño events shifted westward, and most of the WNP was controlled by cyclonic anomaly circulation, which was conducive to the generation and strengthening of TCs, hence the better correlation between TC ACE and ENSO.展开更多
利用1961—2020年黑龙江省冬季逐日气温资料,以连续5 d日平均气温低于一个标准差来判定极端冷事件,进而利用冷事件的持续天数和气温累计距平构建冬季极端寒冷指数(Extreme Cold Index of Winter,ECIW)。在此基础上深入研究了ECIW的年代...利用1961—2020年黑龙江省冬季逐日气温资料,以连续5 d日平均气温低于一个标准差来判定极端冷事件,进而利用冷事件的持续天数和气温累计距平构建冬季极端寒冷指数(Extreme Cold Index of Winter,ECIW)。在此基础上深入研究了ECIW的年代际变化特征及其环流差异。结果表明:近60 a来黑龙江省ECIW呈显著上升趋势,且在1987年前后发生了年代际突变,突变后冬季冷事件强度显著减小。回归分析表明,突变前的1961—1985年,当ECIW强度偏强时,环流呈现北极涛动负位相和弱的欧亚遥相关型正位相分布特征,西北高东南低的环流配置下东亚中高纬环流经向度加大,影响黑龙江省的冷空气较强。而突变后的1991—2020年,环流呈现典型的欧亚遥相关型正位相分布,东亚温带急流显著偏弱,北高南低的配置下黑龙江上空低值系统活跃。对北极涛动、欧亚遥相关型、西伯利亚高压、东亚冬季风等指数与ECIW的相关和偏相关分析表明,北极涛动和欧亚遥相关型是影响ECIW的重要环流因子,1961—1985年北极涛动是主导因子,1991—2020年欧亚遥相关型是主导因子。展开更多
文摘过去的研究表明北大西洋多年代际变化(AMV)对南亚夏季风(SASM)有显著的影响。为进一步研究热带和中高纬北大西洋海温多年代际变化(AMV_Trop和AMV_SPG)对SASM的影响是否存在差异,本文基于地球系统模式(CESM)的大集合数据集(CESM-LE) 1800年的工业革命前参照试验(PiControl)和1920~2005年的42组成员的历史试验(Historical)数据集,通过与观测和再分析资料进行对比,对模式模拟的不同区域AMV、SASM进行了评估,以及对不同区域AMV与SASM之间的联系进行了对比分析,结果显示:1) CESM模式能较好地模拟出观测AMV在热带和热带外区域的主要时空特征,以及SASM区域降水和大气环流的基本特征。2) 在观测结果中,不同区域的正位相AMV均对应于南亚中部区域降水的增加和温度的降低,北部区域降水的减少和温度的升高。3) 在工业革命前参照试验中,AMV、AMV_SPG在正位相时,对应于南亚区域南端降水的增加和北部区域不显著的降水减少,温度变化在AMV正位相时偏暖,在AMV_SPG中表现出大面积偏冷异常;正位相AMV_Trop对应于南亚地区降水的减少和温度的升高。4) 42组历史试验的平均结果与观测相反,不同区域的正位相AMV均对应于南亚地区降水减少。但是,42组试验中有30组表现与观测一致的变化,有12组表现出相反的变化。这表明AMV与SASM的联系具有不稳定性。Past studies have shown that the North Atlantic multiyear intergenerational variability (AMV) has a significant effect on the South Asian summer monsoon (SASM). To further investigate whether there is a difference in the effect of multi-year intergenerational variability of SST (AMV_Trop and AMV_SPG) on SASM between the tropical and mid- to high-latitude North Atlantic, this paper is based on the large ensemble dataset of the Center for Earth System Modeling (CESM) (CESM-LE) Pre-Industrial Revolutionary Reference Experiment (PiControl) of 1800 and the 1920~2005 42 The CESM large ensemble dataset (CESM-LE) 1800 pre-Industrial Revolution Reference Experiment (PiControl) and the Historical Experiment (Historical) dataset from 1920 to 2005 of 42 members of the PiControl group were used to evaluate the model-simulated AMVs and SASMs in different regions by comparing them with the observations and reanalyses as well as to compare and analyze the linkages between AMVs and SASMs in different regions. The results show that: 1) CESM model can simulate the main spatial and temporal characteristics of AMV in tropical and subpolar regions, as well as the basic characteristics of precipitation and atmospheric circulation in SASM region. 2) In the observations, the positive-phase AMV in different regions corresponds to an increase in precipitation and decrease in temperature in the central region of South Asia, and a decrease in precipitation and increase in temperature in the northern region. 3) In the pre-industrial revolution reference experiments, AMV and AMV_SPG in ortho-phase corresponded to an increase in precipitation in the southern end of the South Asian region and a non-significant decrease in precipitation in the northern region, and the temperature change was warm in the ortho-phase of AMV and exhibits large cold-biased anomalies in AMV_SPG;the ortho-phase AMV_Trop corresponded to a decrease in precipitation and an increase in temperature in the South Asian region. 4) The average results of the 42 sets of historical experiments are contrary to the observations, and the ortho-phase AMV in different regions corresponds to a decrease in precipitation in South Asia. However, 30 of the 42 sets of experiments show variations consistent with observations, and 12 sets show opposite variations. This suggests instability in the linkage between AMV and SASM.
文摘文章利用中国气象局发布的热带气旋(TC)最佳路径数据资料,以及NCEP/NCAR大气再分析数据,分析了盛季(7~9月份)、后季(10~11月份)西北太平洋(WNP)TC累积气旋能量(ACE)与ENSO事件相关性的年代际变化。发现WNP TC盛季ACE与ENSO的相关性在1980年发生了年代际的突变,二者相关性由不显著变为显著的正相关。TC后季ACE与ENSO的相关性在1990年前后发生了年代际的突变,相关性由不相关变为显著的正相关。盛季、后季二者相关性年代际转变发生的事件不同,影响机制也不同。盛季ACE与ENSO相关性发生转变的主要原因是连续型ENSO在1980年之前发生频次较高,减弱了ENSO对ACE的影响。后季ACE与ENSO相关性发生转变的原因主要是1990年之前,El Niño多为东太平洋型,在WNP激发的环流异常为偶极子型分布,不能影响ACE的总量,1990年之后,El Niño发生时异常对流的位置偏西,WNP大部分区域被气旋式异常环流控制,有利于TC的生成和加强,因此TC ACE与ENSO有较好的相关性。This paper utilizes the best track data of tropical cyclones from the China Meteorological Administration, along with NCEP/NCAR reanalysis atmospheric data, to analyze the decadal shift in the relationship between the Accumulated Cyclone Energy (ACE) of tropical cyclones (TC) in the Northwest Pacific (WNP) during the peak (July-September) and late (October-November) seasons and ENSO events. It was found that the correlation between WNP TC ACE during the peak season and ENSO underwent a decadal shift in 1980, changing from non-significant to a significant positive correlation. The correlation between late-season TC ACE and ENSO also experienced a decadal shift around 1990, changing from no correlation to a significant positive correlation. The decadal shifts in correlation during the peak and late seasons occurred at different times and were driven by different mechanisms. The shift in the correlation between peak season TC ACE and ENSO is primarily due to the high frequency of continuous-type ENSO events before 1980, which weakened the influence of ENSO on ACE. The reason for the shift in the correlation between late-season TC ACE and ENSO is mainly because before 1990, El Niño was predominantly of the Eastern Pacific type, and the circulation anomalies it triggered in the WNP were of a dipole distribution, which did not affect the total ACE. After 1990, the position of anomalous convection during El Niño events shifted westward, and most of the WNP was controlled by cyclonic anomaly circulation, which was conducive to the generation and strengthening of TCs, hence the better correlation between TC ACE and ENSO.
文摘利用1961—2020年黑龙江省冬季逐日气温资料,以连续5 d日平均气温低于一个标准差来判定极端冷事件,进而利用冷事件的持续天数和气温累计距平构建冬季极端寒冷指数(Extreme Cold Index of Winter,ECIW)。在此基础上深入研究了ECIW的年代际变化特征及其环流差异。结果表明:近60 a来黑龙江省ECIW呈显著上升趋势,且在1987年前后发生了年代际突变,突变后冬季冷事件强度显著减小。回归分析表明,突变前的1961—1985年,当ECIW强度偏强时,环流呈现北极涛动负位相和弱的欧亚遥相关型正位相分布特征,西北高东南低的环流配置下东亚中高纬环流经向度加大,影响黑龙江省的冷空气较强。而突变后的1991—2020年,环流呈现典型的欧亚遥相关型正位相分布,东亚温带急流显著偏弱,北高南低的配置下黑龙江上空低值系统活跃。对北极涛动、欧亚遥相关型、西伯利亚高压、东亚冬季风等指数与ECIW的相关和偏相关分析表明,北极涛动和欧亚遥相关型是影响ECIW的重要环流因子,1961—1985年北极涛动是主导因子,1991—2020年欧亚遥相关型是主导因子。
