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
为探究东亚夏季风(EASM,East Asian summer monsoon)和南亚夏季风(SASM,South Asian summer monsoon)相互作用及其强弱变化对西南地区夏季降水的影响,利用1979—2019年西南地区161站逐日降水观测资料和ERA-5提供的1979—2019年全球再分...为探究东亚夏季风(EASM,East Asian summer monsoon)和南亚夏季风(SASM,South Asian summer monsoon)相互作用及其强弱变化对西南地区夏季降水的影响,利用1979—2019年西南地区161站逐日降水观测资料和ERA-5提供的1979—2019年全球再分析资料,通过对比西南地区夏季标准化降水指数与东亚和南亚夏季风强度指数的相关,提出了东亚夏季风和南亚夏季风的4类协同作用,并分析了4类季风协同作用对西南地区降水的影响。结果表明:(1)EASM和SASM存在强EASM-强SASM、强EASM-弱SASM、弱EASM-弱SASM和弱EASM-强SASM 4类季风协同作用,其对应的协同年降水特征分别为四川盆地西部型、西南全区一致型、四川全盆地型及西南东部型。(2)强EASM-强SASM年,西太平洋副热带高压偏东偏弱,伊朗高压偏西偏弱,印度半岛东北部与中国南海存在两个气旋式环流,EASM将中国南海—西太平洋的水汽输送至西南地区,西南地区整体水汽辐合较弱,多下沉运动,降水较少,成都平原存在较明显的水汽辐合,上升运动明显,降水较多。强EASM-弱SASM年,西太平洋副热带高压偏东偏弱,伊朗高压偏东偏强,反气旋式环流与气旋式环流位于印度半岛南部与西太平洋,EASM将中国南海—西太平洋的水汽输送至西南地区,西南地区有明显的水汽辐合和上升运动,降水较多。弱EASM-弱SASM年,西太平洋副热带高压西伸与东伸的伊朗高压打通,低纬度地区无明显的环流圈,孟加拉湾西侧水汽向北输送至四川盆地,并伴有明显的上升运动,其余地区水汽辐散,气流下沉,降水较少。弱EASM-强SASM年则与强EASM-弱SASM年基本相反。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.
文摘为探究东亚夏季风(EASM,East Asian summer monsoon)和南亚夏季风(SASM,South Asian summer monsoon)相互作用及其强弱变化对西南地区夏季降水的影响,利用1979—2019年西南地区161站逐日降水观测资料和ERA-5提供的1979—2019年全球再分析资料,通过对比西南地区夏季标准化降水指数与东亚和南亚夏季风强度指数的相关,提出了东亚夏季风和南亚夏季风的4类协同作用,并分析了4类季风协同作用对西南地区降水的影响。结果表明:(1)EASM和SASM存在强EASM-强SASM、强EASM-弱SASM、弱EASM-弱SASM和弱EASM-强SASM 4类季风协同作用,其对应的协同年降水特征分别为四川盆地西部型、西南全区一致型、四川全盆地型及西南东部型。(2)强EASM-强SASM年,西太平洋副热带高压偏东偏弱,伊朗高压偏西偏弱,印度半岛东北部与中国南海存在两个气旋式环流,EASM将中国南海—西太平洋的水汽输送至西南地区,西南地区整体水汽辐合较弱,多下沉运动,降水较少,成都平原存在较明显的水汽辐合,上升运动明显,降水较多。强EASM-弱SASM年,西太平洋副热带高压偏东偏弱,伊朗高压偏东偏强,反气旋式环流与气旋式环流位于印度半岛南部与西太平洋,EASM将中国南海—西太平洋的水汽输送至西南地区,西南地区有明显的水汽辐合和上升运动,降水较多。弱EASM-弱SASM年,西太平洋副热带高压西伸与东伸的伊朗高压打通,低纬度地区无明显的环流圈,孟加拉湾西侧水汽向北输送至四川盆地,并伴有明显的上升运动,其余地区水汽辐散,气流下沉,降水较少。弱EASM-强SASM年则与强EASM-弱SASM年基本相反。
