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熊敏诠. 近60年中国日降水量分区及气候特征[J]. 大气科学, 2017, 41(5): 933-948. DOI: 10.3878/j.issn.1006-9895.1703.16169
引用本文: 熊敏诠. 近60年中国日降水量分区及气候特征[J]. 大气科学, 2017, 41(5): 933-948. DOI: 10.3878/j.issn.1006-9895.1703.16169
Minquan XIONG. Climate Regionalization and Characteristics of Daily Precipitation in China in Recent 60 Years[J]. Chinese Journal of Atmospheric Sciences, 2017, 41(5): 933-948. DOI: 10.3878/j.issn.1006-9895.1703.16169
Citation: Minquan XIONG. Climate Regionalization and Characteristics of Daily Precipitation in China in Recent 60 Years[J]. Chinese Journal of Atmospheric Sciences, 2017, 41(5): 933-948. DOI: 10.3878/j.issn.1006-9895.1703.16169

近60年中国日降水量分区及气候特征

Climate Regionalization and Characteristics of Daily Precipitation in China in Recent 60 Years

  • 摘要: 根据中国国家级地面气象站均一化降水数据集,使用1956~2015年512个台站的日降水量资料,通过旋转经验正交函数(REOF)得到七个分区。比较了各分区平均日降水量的年内变化和多年倾向率差异:我国偏南分区的小雨日数减少,大雨、暴雨日数、日降水量的区域年均值增加;偏北分区的小雨、大雨、暴雨日数、降水量年均值为递减;长江中下游区(东北区)日降水量、小雨日数、暴雨日数的年均值的近60年倾向率分别是0.0071 mm a-1(-0.0010 mm a-1)、-0.0729 d a-1(-0.0615 d a-1)、0.0132 d a-1(-0.0007 d a-1)。100°E以西地区:小雨、中雨日数在增加,无雨日数显著减少,日降水量的年均值呈递增特点。通过自相关函数和小波功率谱估计,揭示了七个分区的日降水量年均值普遍存在2~4 a周期震荡。使用NCEP/NCAR月均再分析资料,以区域日降水量年均值为指数得到500 hPa、700 hPa、850 hPa回归风系数场、旱涝年整场水汽通量和水汽通量散度差异场相结合分析,结果表明:"东高西低,南高北低"环流型和区域降水有密切关系,水汽差异场是上述环流特点的反映。

     

    Abstract: Rotated empirical orthogonal function (REOF) analysis was applied in this study to daily precipitation from 1956 to 2015 collected at 512 China national weather stations. These daily precipitation data were extracted from the homogeneous precipitation dataset of China weather station. Seven climate divisions were identified based on the 512 stations data. The long-term annual average precipitation for each station and the average for all stations within each division were compared. The overall climate regimes of the individual stations within all the divisions are generally consistent. In South China, the linear precipitation trend and number trends of heavy rain and rainstorm during 1956-2015 were positive, while the trend of light sprinkle frequency reduced in the past 60 years. In North China, precipitation trend and number trends of light rain, heavy rain and rainstorm were negative. In the middle-lower reaches of the Yangtze River division (Northeast division), the linear precipitation trend and number trends of light rain, heavy rain and rainstorm during 1956-2015 were 0.0071 mm a-1 (-0.0010 mm a-1), -0.0729 d a-1 (-0.0615 d a-1), and 0.0132 d a-1 (-0.0007 d a-1), respectively. To the west of 100°E, precipitation trend and number trend of light-medium rain increased with no significant decrease in rainy days in the past 60 years. Characteristics of annual rainfall change on different time scales were analyzed using the PAUL (Morlet) wavelet analysis, the autocorrelation function, and power spectrum analysis method. The most significant variation of precipitation in China shows a periodic oscillation of 2-4 a. Based on National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis data, wind fields at 500 hPa, 700 hPa, and 850 hPa were regressed on annual average daily precipitation in each division. Differences in moisture flux and moisture flux divergence between dry and wet years were analyzed and compared. Results indicate that the circulation patterns characterized by "east high and west low, south high and north low" between mainland China and the western Pacific in the surface were closely related to precipitation in each division. Moisture distribution was generally consistent with various circulation patterns.

     

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