| 摘要: |
| 该文应用NCEP/NCAR逐日2.5°×2.5°再分析资料、中国1 089个测站的24 h降水资料以及NOAA 2°×2°月平均的SST资料，对2016年梅雨期降水、大尺度环流、水汽输送流函数和势函数及相对应的非辐散分量和辐散分量以及海温异常特征进行分析，结果发现2016年梅雨期降水较常年偏多约40%，且降水区域更偏向长江流域附近，梅雨期间所示特征与其相应环流背景、水汽输送及源汇以及海温异常信号有密不可分的关系：①梅雨期间副高逐渐北抬，后期副高脊线较常年显著偏北约7°，东西进退较明显；②高层南亚高压异常偏东；③江淮附近是水汽辐合的大值区；④由于SSTA（海表面温度异常）等因素影响，江淮附近的汇入气流显著增强。这些原因为该年梅雨提供有利的背景条件，是造成降水偏多，降水区域略偏北的主要因素。 |
| 关键词: 江淮梅雨；海温；高低空急流；副热带高压 |
| DOI： |
| 投稿时间：2019-01-11 |
| 基金项目: |
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| Analysis on the characteristics of Jianghuai mould rain in 2016 |
| MO Yidong,LI Qingjian,WU Liangbiao,YANG Fan |
| (Qiannan Meteorological Bureau,Duyun 558000 , China;Duyun Municipal Meteorological Bureau,Duyun 558000 ,China) |
| Abstract: |
| NCEP/NCAR daily 2.5°×2.5° reanalysis data, observed precipitation data over 1089 weather stations in China and the monthly average 2°×2° SST data of NOAA were used in the paper to analyze the anomalous characteristics of precipitation, large scale circulation, water vapor transport flow function as well as the corresponding non-radiative and divergent components and sea surface temperature in the 2016 mould rain period. The results have shown that precipitation amount during 2016 mould rain period was about 40% above the normal, and the major precipitation area was located along the Changjiang River basin for a longer period abnormally as well. The meteorological characteristics exhibited during the mould rain period were most closely related to their corresponding atmospheric circulation background, water vapor transport and source sinks, and sea surface temperature anomalies as described as follows. ①During the 2016 mould rain period, the western Pacific subtropical anticyclone (WPSA) was gradually moving northward, and the late secondary high ridge line was obviously located about 7° further north in the later period than the normal years. It was also more frequently moving westward and retreating eastward than the normal years. ②The South Asian high pressure system at the upper troposphere was abnormally toward the east.③During the 2016 mould rain period, the center of the maximum water vapor convergence over the world was located in Jianghuai River Basin. ④Due to the influence of sea surface temperature anomalies and other factors, the airflow in the Jianghuai River Basin in the 2016 mould rain period was significantly enhanced. All the factors described above provided promising atmospheric circulation conditions to produce much more precipitation amount during the 2016 mould rain period,and major precipitation area was abnormally located in the northern area. |
| Key words: Jianghuai mould rain； sea surface temperature； high and low jet； subtropical high |
