为了研究中国西南雨季降水变化和海温的关系,利用西南地区1960~2022年81站共63年的逐日气象观测降水量资料、同期英国哈德莱中心月平均海表温度(SST)资料(格点分辨率为1˚ × 1˚)、欧洲气象资料中心(ERA-interim)的月平均降水再分析...为了研究中国西南雨季降水变化和海温的关系,利用西南地区1960~2022年81站共63年的逐日气象观测降水量资料、同期英国哈德莱中心月平均海表温度(SST)资料(格点分辨率为1˚ × 1˚)、欧洲气象资料中心(ERA-interim)的月平均降水再分析资料(格点分辨率为0.25˚ × 0.25˚)。通过相关分析、经验正交函数分解(EOF)和奇异值分解(SVD)等方法,对西南雨季降水变化与全球SST之间的关系进行了研究分析,结果表明:1) 西南地区63年的雨季降水空间分布不均,呈现东多西少,南多北少的态势,同时,其与前冬、春季澳大利亚东北部太平洋,夏、秋季北印度洋和同期5⁓10月份的北印度洋海温呈现显著负相关关系,即关键区海温异常偏暖(冷),西南雨季降水偏少(多)。2) EOF分析表明:在第1模态下,前一年冬季和当年春季关键区海域海温的分布形式多呈现出西高东低的形式,包括了东太平洋冷舌和西太平洋暖池形态,并且在千禧年之前大部分都是海温多为偏冷状态;而千禧年之后关键区海温由偏冷转为偏暖状态。而当年夏秋季和雨季同期关键区海域海温呈现出全区一致偏暖状态,并且在90年代之后海温从偏冷转变为偏暖状态,其第2空间模态为印度洋正偶极子分布形式。3) SVD分解表明:关键区海温与川西高原地区雨季降水存在正相关关系,而与川东、黔南和云南呈现出一个显著的负相关性,不同季节的海温关键区影响的降水大值区域可能略有不同,但总体来说,当关键区海温异常偏高(低),川西高原的雨季降水异常偏多(少),而其余大部分地区降水异常偏少(多);其分解结果与相关系数的分析结果基本一致并且近年来西南地区的雨季降水呈现出逐年减少的态势。In order to study the relationship between precipitation change and sea surface temperature in the rainy season in southwest China, the daily meteorological observations of 81 stations in Southwest China from 1960 to 2022 for a total of 63 years were used measured precipitation data, the monthly mean sea surface temperature (SST) data of the Hadley Center in the United Kingdom (grid resolution of 1˚ × 1˚) and the monthly mean precipitation reanalysis data of the European Meteorological Data Center (ERA-interim) (grid resolution of 0.25˚ × 0.25˚). The relationship between precipitation change in the rainy season in southwest China and global SST was analyzed by correlation analysis, empirical orthogonal function decomposition (EOF) and singular value decomposition (SVD). The results shows: 1) The spatial distribution of rainy season precipitation in southwest China in 63 years was uneven, showing a trend of more precipitation in the east and less in the west, and more in the south and less in the north, and at the same time, it was significantly negatively correlated with the sea surface temperature in the Pacific Ocean in northeast Australia in the early winter and spring, the northern Indian Ocean in summer and autumn, and the northern Indian Ocean in May and October in the same period, that is, the SST in the key areas was abnormally warm (cold), and the precipitation in the southwest rainy season was less (more). 2) EOF analysis shows that in the first mode, the distribution of sea surface temperature in the key areas in the winter and spring of the previous year mostly shows the form of high in the west and low in the east, including the cold tongue of the eastern Pacific and the warm pool of the western Pacific, and most of the SST is in a cold state before the millennium. After the turn of the millennium, the sea surface temperature in key areas changed from cold to warm. However, the SST in the key areas of the key area in the same period of summer, autumn and rainy season showed a uniform warming state in the whole region, and after the 90s, the SST changed from cold to warm, and the second spatial mode was the normal dipole distribution of the Indian Ocean. 3) SVD decomposition showed that the sea surface temperature in the key area and the rainy season in the western Sichuan Plateau. There is a positive correlation with precipitation, and there is a significant negative correlation with eastern Sichuan, southern Guizhou and Yunnan, and the influence of key areas of SST in different seasons is positive. The precipitation area may be slightly different, but in general, when the sea surface temperature in the key area is abnormally high (low), the rainy season precipitation in the western Sichuan Plateau is abnormally biased more (less), while most of the rest of the precipitation is abnormally low (more). The decomposition results are basically consistent with the analysis results of the correlation coefficient and in recent years. The rainy season precipitation in southwest China shows a decreasing trend year by year.展开更多
为研究西南雨季降水的时空变化特征,利用1960~2022年西南地区81个气象站点的逐日气象降水量观测资料,通过EOF分解、Morlet小波分析和EEMD分析等方法,对西南地区雨季降水量的多尺度变化特征进行了详细研究。结果表明:1) 西南地区63年来...为研究西南雨季降水的时空变化特征,利用1960~2022年西南地区81个气象站点的逐日气象降水量观测资料,通过EOF分解、Morlet小波分析和EEMD分析等方法,对西南地区雨季降水量的多尺度变化特征进行了详细研究。结果表明:1) 西南地区63年来雨季降水量空间分布不均匀,大体有由东向西逐渐递减,以及由南向北逐渐递减的变化趋势。川西高原为降水量低值区,雅安、峨眉以及云南南部为降水量高值区。西南地区趋势系数正值区和负值区交错分布,正值区主要在川西高原以及川东和贵州,负值区在云南地区。2) EOF分析表明:西南地区雨季降水量第1模态为全区一致型,大值中心位于云南地区以及四川中南部。西南地区雨季降水量第2模态显示为北负南正型,正值大值中心位于云南地区,负值大值区位于川西和川东。西南地区雨季降水量第3模态显示为东北到西南正负交错的分布类型。西南地区雨季降水量第4模态为西负东正的分布类型。西南地区雨季降水量第5模态显示为东北到西南呈正负交错的分布类型。3) 小波分析表明西南地区雨季降水量主要有3~4年、7~8年、10~14年、15~23年的变化周期;EEMD分解表明西南地区雨季降水量主要有2.66年、5.33年、10年、21.3年的变化周期。由此可知,西南地区主要存在4年、8年和20年左右的周期。In order to study the spatio-temporal variation of rainy season precipitation in Southwest China, the multi-scale variation of rainy season precipitation in Southwest China was studied in detail by means of EOF decomposition, Morlet wavelet analysis and EEMD analysis, based on the daily meteorological precipitation observation data of 81 meteorological stations in Southwest China during 1960~2022. The results show that: 1) The spatial distribution of rainy season precipitation in Southwest China in the past 63 years is uneven, with a gradual decline from east to west and from south to north. The West Sichuan Plateau has a low precipitation value, while Ya’an, E’mei and southern Yunnan have a high precipitation value. The positive and negative regions of the trend coefficient in Southwest China are interleaved, the positive regions are mainly in the west Sichuan Plateau, the east Sichuan and Guizhou, and the negative regions are in Yunnan. 2) The EOF analysis shows that the first mode of precipitation in the rainy season in southwest China is the uniform type in the whole region, and the large value center is located in Yunnan and central and southern Sichuan. The second mode of rainy season precipitation in Southwest China shows that the north is negative and the south is positive. The positive value center is located in Yunnan, and the negative value area is located in west and east Sichuan. The third mode of precipitation in the rainy season in Southwest China shows the distribution type of positive and negative interleaving from northeast to southwest. The fourth mode of precipitation in the rainy season in Southwest China is the distribution type of west negative and east positive. The fifth mode of precipitation of rainy season in Southwest China shows the distribution type of positive and negative from northeast to southwest. 3) Wavelet analysis shows that the rainy season precipitation in Southwest China mainly has a change cycle of 3~4 years, 7~8 years, 10-14 years and 15~23 years. The EEMD decomposition shows that the rainy season precipitation in Southwest China mainly has a change cycle of 2.66 years, 5.33 years, 10 years and 21.3 years. It can be seen that there are cycles of about 4 years, 8 years and 20 years in Southwest China.展开更多
文摘为了研究中国西南雨季降水变化和海温的关系,利用西南地区1960~2022年81站共63年的逐日气象观测降水量资料、同期英国哈德莱中心月平均海表温度(SST)资料(格点分辨率为1˚ × 1˚)、欧洲气象资料中心(ERA-interim)的月平均降水再分析资料(格点分辨率为0.25˚ × 0.25˚)。通过相关分析、经验正交函数分解(EOF)和奇异值分解(SVD)等方法,对西南雨季降水变化与全球SST之间的关系进行了研究分析,结果表明:1) 西南地区63年的雨季降水空间分布不均,呈现东多西少,南多北少的态势,同时,其与前冬、春季澳大利亚东北部太平洋,夏、秋季北印度洋和同期5⁓10月份的北印度洋海温呈现显著负相关关系,即关键区海温异常偏暖(冷),西南雨季降水偏少(多)。2) EOF分析表明:在第1模态下,前一年冬季和当年春季关键区海域海温的分布形式多呈现出西高东低的形式,包括了东太平洋冷舌和西太平洋暖池形态,并且在千禧年之前大部分都是海温多为偏冷状态;而千禧年之后关键区海温由偏冷转为偏暖状态。而当年夏秋季和雨季同期关键区海域海温呈现出全区一致偏暖状态,并且在90年代之后海温从偏冷转变为偏暖状态,其第2空间模态为印度洋正偶极子分布形式。3) SVD分解表明:关键区海温与川西高原地区雨季降水存在正相关关系,而与川东、黔南和云南呈现出一个显著的负相关性,不同季节的海温关键区影响的降水大值区域可能略有不同,但总体来说,当关键区海温异常偏高(低),川西高原的雨季降水异常偏多(少),而其余大部分地区降水异常偏少(多);其分解结果与相关系数的分析结果基本一致并且近年来西南地区的雨季降水呈现出逐年减少的态势。In order to study the relationship between precipitation change and sea surface temperature in the rainy season in southwest China, the daily meteorological observations of 81 stations in Southwest China from 1960 to 2022 for a total of 63 years were used measured precipitation data, the monthly mean sea surface temperature (SST) data of the Hadley Center in the United Kingdom (grid resolution of 1˚ × 1˚) and the monthly mean precipitation reanalysis data of the European Meteorological Data Center (ERA-interim) (grid resolution of 0.25˚ × 0.25˚). The relationship between precipitation change in the rainy season in southwest China and global SST was analyzed by correlation analysis, empirical orthogonal function decomposition (EOF) and singular value decomposition (SVD). The results shows: 1) The spatial distribution of rainy season precipitation in southwest China in 63 years was uneven, showing a trend of more precipitation in the east and less in the west, and more in the south and less in the north, and at the same time, it was significantly negatively correlated with the sea surface temperature in the Pacific Ocean in northeast Australia in the early winter and spring, the northern Indian Ocean in summer and autumn, and the northern Indian Ocean in May and October in the same period, that is, the SST in the key areas was abnormally warm (cold), and the precipitation in the southwest rainy season was less (more). 2) EOF analysis shows that in the first mode, the distribution of sea surface temperature in the key areas in the winter and spring of the previous year mostly shows the form of high in the west and low in the east, including the cold tongue of the eastern Pacific and the warm pool of the western Pacific, and most of the SST is in a cold state before the millennium. After the turn of the millennium, the sea surface temperature in key areas changed from cold to warm. However, the SST in the key areas of the key area in the same period of summer, autumn and rainy season showed a uniform warming state in the whole region, and after the 90s, the SST changed from cold to warm, and the second spatial mode was the normal dipole distribution of the Indian Ocean. 3) SVD decomposition showed that the sea surface temperature in the key area and the rainy season in the western Sichuan Plateau. There is a positive correlation with precipitation, and there is a significant negative correlation with eastern Sichuan, southern Guizhou and Yunnan, and the influence of key areas of SST in different seasons is positive. The precipitation area may be slightly different, but in general, when the sea surface temperature in the key area is abnormally high (low), the rainy season precipitation in the western Sichuan Plateau is abnormally biased more (less), while most of the rest of the precipitation is abnormally low (more). The decomposition results are basically consistent with the analysis results of the correlation coefficient and in recent years. The rainy season precipitation in southwest China shows a decreasing trend year by year.
文摘为研究西南雨季降水的时空变化特征,利用1960~2022年西南地区81个气象站点的逐日气象降水量观测资料,通过EOF分解、Morlet小波分析和EEMD分析等方法,对西南地区雨季降水量的多尺度变化特征进行了详细研究。结果表明:1) 西南地区63年来雨季降水量空间分布不均匀,大体有由东向西逐渐递减,以及由南向北逐渐递减的变化趋势。川西高原为降水量低值区,雅安、峨眉以及云南南部为降水量高值区。西南地区趋势系数正值区和负值区交错分布,正值区主要在川西高原以及川东和贵州,负值区在云南地区。2) EOF分析表明:西南地区雨季降水量第1模态为全区一致型,大值中心位于云南地区以及四川中南部。西南地区雨季降水量第2模态显示为北负南正型,正值大值中心位于云南地区,负值大值区位于川西和川东。西南地区雨季降水量第3模态显示为东北到西南正负交错的分布类型。西南地区雨季降水量第4模态为西负东正的分布类型。西南地区雨季降水量第5模态显示为东北到西南呈正负交错的分布类型。3) 小波分析表明西南地区雨季降水量主要有3~4年、7~8年、10~14年、15~23年的变化周期;EEMD分解表明西南地区雨季降水量主要有2.66年、5.33年、10年、21.3年的变化周期。由此可知,西南地区主要存在4年、8年和20年左右的周期。In order to study the spatio-temporal variation of rainy season precipitation in Southwest China, the multi-scale variation of rainy season precipitation in Southwest China was studied in detail by means of EOF decomposition, Morlet wavelet analysis and EEMD analysis, based on the daily meteorological precipitation observation data of 81 meteorological stations in Southwest China during 1960~2022. The results show that: 1) The spatial distribution of rainy season precipitation in Southwest China in the past 63 years is uneven, with a gradual decline from east to west and from south to north. The West Sichuan Plateau has a low precipitation value, while Ya’an, E’mei and southern Yunnan have a high precipitation value. The positive and negative regions of the trend coefficient in Southwest China are interleaved, the positive regions are mainly in the west Sichuan Plateau, the east Sichuan and Guizhou, and the negative regions are in Yunnan. 2) The EOF analysis shows that the first mode of precipitation in the rainy season in southwest China is the uniform type in the whole region, and the large value center is located in Yunnan and central and southern Sichuan. The second mode of rainy season precipitation in Southwest China shows that the north is negative and the south is positive. The positive value center is located in Yunnan, and the negative value area is located in west and east Sichuan. The third mode of precipitation in the rainy season in Southwest China shows the distribution type of positive and negative interleaving from northeast to southwest. The fourth mode of precipitation in the rainy season in Southwest China is the distribution type of west negative and east positive. The fifth mode of precipitation of rainy season in Southwest China shows the distribution type of positive and negative from northeast to southwest. 3) Wavelet analysis shows that the rainy season precipitation in Southwest China mainly has a change cycle of 3~4 years, 7~8 years, 10-14 years and 15~23 years. The EEMD decomposition shows that the rainy season precipitation in Southwest China mainly has a change cycle of 2.66 years, 5.33 years, 10 years and 21.3 years. It can be seen that there are cycles of about 4 years, 8 years and 20 years in Southwest China.
