为了研究西南地区雨季降水不同年代水汽输送的对比,选取了云南和四川的全部地区,以及贵州和重庆的部分地区共81个气象台站资料,从1960年伊始,到2022年的每年雨季的观测资料,还采用了ERA5从1940年至今的压力水平和单一水平的月平均数据,...为了研究西南地区雨季降水不同年代水汽输送的对比,选取了云南和四川的全部地区,以及贵州和重庆的部分地区共81个气象台站资料,从1960年伊始,到2022年的每年雨季的观测资料,还采用了ERA5从1940年至今的压力水平和单一水平的月平均数据,数据的分辨率是0.25˚ × 0.25˚。凭借天气学诊断分析、multiquadric插值算法、相关系数的显著性检验等方法,对西南地区的雨季不同年代水输送进行了详尽的对比分析,其研究结论表明:1) 西南地区整体水汽输送与全球气候变化紧密相关,水汽输送的基本形势是地形上西北方位弱,正东和正南方位强。拥有的若干传统高值区在近30年来均呈减弱趋势,其中云贵交界减弱最为明显,而传统低值区的水汽输送趋势与整体保持一致。2) 对于传统的高值区,水汽输送情况并不一致。对于传统高值区,近30年来减弱程度从高到低分别为云贵交界,雅安周边,云南南部,雅安周边和以及云南南部还将维持稳定的高值降水。3) 存在一个异常带,约位于104˚E附近,这些区域常与西南地区整体呈相反趋势,拥有独立的水汽输送通道,是异常水汽输送的高发区。异常带有向周围扩散的趋势,表现为沿104˚E线向外扩散,这一异常带更多受到来自孟湾向北方向的水汽输送,并引导产生异常降水,伴随西南整体周期性的水汽输送增强和异常降水增多,104˚E周边地区将易发异常低值。To study the contrast of water transport during the rainy season across different decades in Southwest China, data from 81 meteorological stations in Yunnan and Sichuan provinces, as well as parts of Guizhou and Chongqing, were selected. The observation data span from the rainy seasons of 1960 to 2022, and ERA5 monthly average data from pressure levels and single levels, with a resolution of 0.25˚ × 0.25˚, were used from 1940 to the present. Using synoptic diagnostic analysis, multiquadric interpolation algorithm, and significance tests of correlation coefficients, a detailed comparative analysis of water transport during the rainy seasons in different decades in Southwest China was conducted. The study concluded that: 1) The overall moisture transport in Southwest China is closely related to global climate change, with a basic pattern of weak transport in the northwest and strong transport in the east and south directions due to topography. Traditional high-value areas have shown a weakening trend in the past 30 years, with the Yunnan-Guizhou border weakening the most significantly, while the trend in traditional low-value areas remains consistent with the overall pattern. 2) For traditional high-value areas, the moisture transport situation is not uniform. In the past 30 years, the degree of weakening from highest to lowest is as follows: Yunnan-Guizhou border, around Ya’an, and southern Yunnan. Both around Ya’an and southern Yunnan will maintain stable high-value precipitation. 3) There is an anomalous belt approximately located near 104˚E, where these regions often show a trend opposite to the overall trend in Southwest China, having independent moisture transport channels and being high-incidence areas of anomalous moisture transport. This anomalous belt shows a tendency to spread outward along the 104˚E line, more influenced by moisture transport from the north of the Bay of Bengal, leading to anomalous precipitation. Accompanied by the periodic enhancement of moisture transport and increased anomalous precipitation in Southwest China, the areas around 104˚E are prone to anomalously low values.展开更多
为了更好地对西南雨季降水的时空变化特征进行研究,利用中国西南地区1960~2022年81个气象站点共63年的逐日降水量气象观测资料,通过旋转经验正交函数分解(REOF)、Mann-Kendall突变检验和Morlet小波分析等研究方法,揭示西南地区降水的时...为了更好地对西南雨季降水的时空变化特征进行研究,利用中国西南地区1960~2022年81个气象站点共63年的逐日降水量气象观测资料,通过旋转经验正交函数分解(REOF)、Mann-Kendall突变检验和Morlet小波分析等研究方法,揭示西南地区降水的时空分布特征、长期变化趋势以及周期变化特征。分析结果表明:1) 西南地区1960~2022年来主要有3个降水大值区,分别为云南南部、贵州西南部以及四川中东部地区,降水量分布自东、南向西、北逐渐递减。2) 在EOF分析的基础上进行REOF分解,将西南地区分为5个区:1区为云南区,2区为川西高原区,3区为川中区,4区为贵州区,5区为川东区。3) 5个区域的雨季降水除2区呈现缓慢上升趋势外,其余区域均呈现程度不同的下降趋势,5个区域的雨季降水突变主要集中在21世纪初期,且突变后呈现不同的变化趋势。变化周期主要以5~10a、准5a周期为主。In order to better study the spatio-temporal variation characteristics of rainy season precipitation in Southwest China, the day-by-day precipitation meteorological observations of 81 meteorological stations in Southwest China for a total of 63 years from 1960 to 2022 are utilized to reveal the spatio-temporal precipitation in Southwest China through the Rotated Empirical Orthogonal Function Decomposition (REOF), the Mann-Kendall Mutation Test, and the Morlet wavelet analysis and other research methods to reveal the spatial and temporal distribution characteristics of precipitation, long-term trends and cycle change characteristics in Southwest China. The analysis results show that: 1) there are three major precipitation areas in Southwest China from 1960 to 2022, namely, southern Yunnan, southwestern Guizhou, and east-central Sichuan, and the distribution of precipitation gradually decreases from east and south to west and north. 2) REOF decomposition is carried out on the basis of EOF analysis, and the southwest region is divided into 5 zones: zone 1 is Yunnan, zone 2 is the western Sichuan plateau zone, zone 3 is the central Sichuan zone, zone 4 is the Guizhou zone, and zone 5 is the eastern Sichuan zone. 3) The rainy season precipitation in the five regions shows a decreasing trend in varying degrees, except for region 2, which shows a slowly increasing trend. The sudden changes in rainy season precipitation in the five regions are mainly concentrated at the beginning of the 21st century and show different trends after the sudden changes. The change cycles are mainly 5~10a and quasi 5a cycles.展开更多
文摘为了研究西南地区雨季降水不同年代水汽输送的对比,选取了云南和四川的全部地区,以及贵州和重庆的部分地区共81个气象台站资料,从1960年伊始,到2022年的每年雨季的观测资料,还采用了ERA5从1940年至今的压力水平和单一水平的月平均数据,数据的分辨率是0.25˚ × 0.25˚。凭借天气学诊断分析、multiquadric插值算法、相关系数的显著性检验等方法,对西南地区的雨季不同年代水输送进行了详尽的对比分析,其研究结论表明:1) 西南地区整体水汽输送与全球气候变化紧密相关,水汽输送的基本形势是地形上西北方位弱,正东和正南方位强。拥有的若干传统高值区在近30年来均呈减弱趋势,其中云贵交界减弱最为明显,而传统低值区的水汽输送趋势与整体保持一致。2) 对于传统的高值区,水汽输送情况并不一致。对于传统高值区,近30年来减弱程度从高到低分别为云贵交界,雅安周边,云南南部,雅安周边和以及云南南部还将维持稳定的高值降水。3) 存在一个异常带,约位于104˚E附近,这些区域常与西南地区整体呈相反趋势,拥有独立的水汽输送通道,是异常水汽输送的高发区。异常带有向周围扩散的趋势,表现为沿104˚E线向外扩散,这一异常带更多受到来自孟湾向北方向的水汽输送,并引导产生异常降水,伴随西南整体周期性的水汽输送增强和异常降水增多,104˚E周边地区将易发异常低值。To study the contrast of water transport during the rainy season across different decades in Southwest China, data from 81 meteorological stations in Yunnan and Sichuan provinces, as well as parts of Guizhou and Chongqing, were selected. The observation data span from the rainy seasons of 1960 to 2022, and ERA5 monthly average data from pressure levels and single levels, with a resolution of 0.25˚ × 0.25˚, were used from 1940 to the present. Using synoptic diagnostic analysis, multiquadric interpolation algorithm, and significance tests of correlation coefficients, a detailed comparative analysis of water transport during the rainy seasons in different decades in Southwest China was conducted. The study concluded that: 1) The overall moisture transport in Southwest China is closely related to global climate change, with a basic pattern of weak transport in the northwest and strong transport in the east and south directions due to topography. Traditional high-value areas have shown a weakening trend in the past 30 years, with the Yunnan-Guizhou border weakening the most significantly, while the trend in traditional low-value areas remains consistent with the overall pattern. 2) For traditional high-value areas, the moisture transport situation is not uniform. In the past 30 years, the degree of weakening from highest to lowest is as follows: Yunnan-Guizhou border, around Ya’an, and southern Yunnan. Both around Ya’an and southern Yunnan will maintain stable high-value precipitation. 3) There is an anomalous belt approximately located near 104˚E, where these regions often show a trend opposite to the overall trend in Southwest China, having independent moisture transport channels and being high-incidence areas of anomalous moisture transport. This anomalous belt shows a tendency to spread outward along the 104˚E line, more influenced by moisture transport from the north of the Bay of Bengal, leading to anomalous precipitation. Accompanied by the periodic enhancement of moisture transport and increased anomalous precipitation in Southwest China, the areas around 104˚E are prone to anomalously low values.
文摘为了更好地对西南雨季降水的时空变化特征进行研究,利用中国西南地区1960~2022年81个气象站点共63年的逐日降水量气象观测资料,通过旋转经验正交函数分解(REOF)、Mann-Kendall突变检验和Morlet小波分析等研究方法,揭示西南地区降水的时空分布特征、长期变化趋势以及周期变化特征。分析结果表明:1) 西南地区1960~2022年来主要有3个降水大值区,分别为云南南部、贵州西南部以及四川中东部地区,降水量分布自东、南向西、北逐渐递减。2) 在EOF分析的基础上进行REOF分解,将西南地区分为5个区:1区为云南区,2区为川西高原区,3区为川中区,4区为贵州区,5区为川东区。3) 5个区域的雨季降水除2区呈现缓慢上升趋势外,其余区域均呈现程度不同的下降趋势,5个区域的雨季降水突变主要集中在21世纪初期,且突变后呈现不同的变化趋势。变化周期主要以5~10a、准5a周期为主。In order to better study the spatio-temporal variation characteristics of rainy season precipitation in Southwest China, the day-by-day precipitation meteorological observations of 81 meteorological stations in Southwest China for a total of 63 years from 1960 to 2022 are utilized to reveal the spatio-temporal precipitation in Southwest China through the Rotated Empirical Orthogonal Function Decomposition (REOF), the Mann-Kendall Mutation Test, and the Morlet wavelet analysis and other research methods to reveal the spatial and temporal distribution characteristics of precipitation, long-term trends and cycle change characteristics in Southwest China. The analysis results show that: 1) there are three major precipitation areas in Southwest China from 1960 to 2022, namely, southern Yunnan, southwestern Guizhou, and east-central Sichuan, and the distribution of precipitation gradually decreases from east and south to west and north. 2) REOF decomposition is carried out on the basis of EOF analysis, and the southwest region is divided into 5 zones: zone 1 is Yunnan, zone 2 is the western Sichuan plateau zone, zone 3 is the central Sichuan zone, zone 4 is the Guizhou zone, and zone 5 is the eastern Sichuan zone. 3) The rainy season precipitation in the five regions shows a decreasing trend in varying degrees, except for region 2, which shows a slowly increasing trend. The sudden changes in rainy season precipitation in the five regions are mainly concentrated at the beginning of the 21st century and show different trends after the sudden changes. The change cycles are mainly 5~10a and quasi 5a cycles.
