利用1967—2009年的逐月海表温度(Sea Surface Temperature,SST)资料和降水资料,以及经验正交函数(Empirical Orthogonal Function,EOF)和相关分析方法,探讨了亚印太交汇区(Joining Area of Asia and Indian-Pacific Ocean,AIPO)SST的...利用1967—2009年的逐月海表温度(Sea Surface Temperature,SST)资料和降水资料,以及经验正交函数(Empirical Orthogonal Function,EOF)和相关分析方法,探讨了亚印太交汇区(Joining Area of Asia and Indian-Pacific Ocean,AIPO)SST的时空分布及其对中国降水的影响。结果表明:海表温度EOF分析第1主分量(即EOF1)的空间分布在整个AIPO区为均一分布,时间系数呈现出明显的年代际变化特征。在年代际尺度上,当AIPO区的SST升高后,北太平洋地区SST开始降低,在11个月后达到最低。另外,AIPO区的SST升高会使南海季风区和东亚季风区的降水增加,使青藏高原西部降水减少。第2主分量(即EOF2)的空间分布在西太平洋基本与东印度洋(包括南海地区)为反相变化,时间系数呈现出明显的2 a和4~5 a为主的年际振荡周期。当Ni o 3.4区SST出现正异常后4个月左右,东印度洋地区有SST正异常,而西太平洋地区有SST负异常。西太平洋地区的SST升高及东印度洋地区的SST降低将导致西北太平洋地区降水增加,东北和华北地区降水减少。而且,AIPO区SST第二模态影响华北和东北的降水要比西北太平洋地区至少超前3个月。展开更多
The climatological characteristics of the moisture budget over the joining area of Asia and the IndianPacific Ocean (AIPO) and its adjacent regions as well as their anomalies have been estimated in this study. The m...The climatological characteristics of the moisture budget over the joining area of Asia and the IndianPacific Ocean (AIPO) and its adjacent regions as well as their anomalies have been estimated in this study. The main results are as follows. In the winter, the northeasterly moisture transport covers the extensive areas at the lower latitudes of the AIPO. The westerly and northerly moisture transport is the major source and the South Indian Ocean (SIO) is the moisture sink. In the summer, influenced by the southwesterly monsoonal wind, the crossequatorial southwesterly moisture transport across Somali originating from the SIO is transported through the Arabian Sea (AS), the Bay of Bengal (BOB), and the South China Sea (SCS) to eastern China. The AIPO is controlled by the southwesterly moisture transport. The net moisture influx over the AIPO has obvious interannual and interdecadal variations. From the mid- or late 1970s, the influxes over the SIO, the AS, the northern part of the western North Pacific (NWNP), and North China (NC) as well as South China (SC) begin to decrease abruptly, while those over Northeast China (NEC) and the Yangtze River-Huaihe River basins (YHRB) have increased remarkably. As a whole, the net moisture influxes over the BOB and the southern part of the western North Pacific (SWNP) in the recent 50 years take on a linear increasing trend. However, the transition timing for these two regions is different with the former being at the mid- or late 1980s and the latter occurring earlier, approximately at the early stage of the 1970s. The anomalous moisture source associated with the precipitation anomalies is different from the normal conditions of the summer precipitation. For the drought or flood years or the years of E1 Nifio and its following years, the anomalous moisture transport originating from the western North Pacific (WNP) is the vital source of the anomalous precipitation over eastern China, which is greatly related with the variat展开更多
文摘利用1967—2009年的逐月海表温度(Sea Surface Temperature,SST)资料和降水资料,以及经验正交函数(Empirical Orthogonal Function,EOF)和相关分析方法,探讨了亚印太交汇区(Joining Area of Asia and Indian-Pacific Ocean,AIPO)SST的时空分布及其对中国降水的影响。结果表明:海表温度EOF分析第1主分量(即EOF1)的空间分布在整个AIPO区为均一分布,时间系数呈现出明显的年代际变化特征。在年代际尺度上,当AIPO区的SST升高后,北太平洋地区SST开始降低,在11个月后达到最低。另外,AIPO区的SST升高会使南海季风区和东亚季风区的降水增加,使青藏高原西部降水减少。第2主分量(即EOF2)的空间分布在西太平洋基本与东印度洋(包括南海地区)为反相变化,时间系数呈现出明显的2 a和4~5 a为主的年际振荡周期。当Ni o 3.4区SST出现正异常后4个月左右,东印度洋地区有SST正异常,而西太平洋地区有SST负异常。西太平洋地区的SST升高及东印度洋地区的SST降低将导致西北太平洋地区降水增加,东北和华北地区降水减少。而且,AIPO区SST第二模态影响华北和东北的降水要比西北太平洋地区至少超前3个月。
基金sponsored by "973" Program No. 2006CB403604National Technol-ogy Support Program (2007BAC03A01)the National Natural Science Foundation of China under Grant Nos.40531006 and 40576012
文摘The climatological characteristics of the moisture budget over the joining area of Asia and the IndianPacific Ocean (AIPO) and its adjacent regions as well as their anomalies have been estimated in this study. The main results are as follows. In the winter, the northeasterly moisture transport covers the extensive areas at the lower latitudes of the AIPO. The westerly and northerly moisture transport is the major source and the South Indian Ocean (SIO) is the moisture sink. In the summer, influenced by the southwesterly monsoonal wind, the crossequatorial southwesterly moisture transport across Somali originating from the SIO is transported through the Arabian Sea (AS), the Bay of Bengal (BOB), and the South China Sea (SCS) to eastern China. The AIPO is controlled by the southwesterly moisture transport. The net moisture influx over the AIPO has obvious interannual and interdecadal variations. From the mid- or late 1970s, the influxes over the SIO, the AS, the northern part of the western North Pacific (NWNP), and North China (NC) as well as South China (SC) begin to decrease abruptly, while those over Northeast China (NEC) and the Yangtze River-Huaihe River basins (YHRB) have increased remarkably. As a whole, the net moisture influxes over the BOB and the southern part of the western North Pacific (SWNP) in the recent 50 years take on a linear increasing trend. However, the transition timing for these two regions is different with the former being at the mid- or late 1980s and the latter occurring earlier, approximately at the early stage of the 1970s. The anomalous moisture source associated with the precipitation anomalies is different from the normal conditions of the summer precipitation. For the drought or flood years or the years of E1 Nifio and its following years, the anomalous moisture transport originating from the western North Pacific (WNP) is the vital source of the anomalous precipitation over eastern China, which is greatly related with the variat