福建雨季降水时空非均匀分布特征分析

Analysis on N character of Precipitation During Rainy Season in Fujian Province

利用福建53年雨季（5～6月）66个常规气象站月降水资料、NCEP/NCAR月平均再分析格点资料及NOAA海温重建资料，使用经验正交函数分解（EOF）、奇异值分解（SVD）、相关分析等方法，分析福建雨季降水的时空分布特征，结果表明：福建雨季的降水在空间上表现一致，即全省旱或全省涝；但存在显著的空间非均匀分布的第二类分布特征，即南旱北涝或南涝北旱。通过分析南北不均匀分布异常年的同期、前期大气环流和海洋特征，发现南旱北涝年近地面层温度场分布呈显著的北冷南暖特征，西太平洋副热带高压偏西偏强，且位置偏南，副高北侧低层较强的西南风将暖湿水汽输送到较北位置，此时南海夏季风强度偏弱，赤道中东太平洋为异常冷水覆盖；前期冬季乌拉尔山阻高偏强、西太平洋副高面积偏大、强度偏强、西伸点偏西，赤道中东太平洋海温偏高而西风漂流区海温偏低。南涝北旱年则基本反之。研究结果揭示了福建省降水时空分布不均的气象基础，对农事安排与防旱抗涝工作具有指导意义。

Based on the data of monthly precipitation of 53 years from 66 conventional meteorological stations , monthly mean re-analysis lattice point data of NCEP/NCAR and re-established data of sea temperature from NOAA ,temporal and spatial characters of precipitation during rainy season in Fujian province were studied by using empirical orthogonal function decomposition （EOF） ,singular value decomposition （SVD） and correlation analysis methods .The results showed that the precipitation during rainy season in Fujian had an spatial character ,which was either drought or flood in all the provincial areas . In addition , the precipitation along with longitude direction presented a heterogeneous distributing character ,which was either flood in south and drought in north or flood in north and drought in south .With the analysis on general atmospheric circulation and ocean character in the abnormal years ,the distribution of temperature field at ground level presented a remarkable character of cold in north and warm in south .Whilst ,the western pacific subtropical high showed westerly direction and strong ,and the stronger southwest wind at lower layer in north of the western pacific subtropical high pushed moisture to far north location . Meanwhile ,summer wind in southern ocean became weaken ,the middle-east equator pacific ocean were covered with extremely cold water .The blocking high turned to be great during early period in winter at Urals ,and the western pacific subtropical high was in large scale ,great intensity and extending to far west .The temperature in the middle-east equator pacific ocean became high ,then became low in west wind drift region .The reverse was true in＆amp;nbsp;the years of flood in south and drought in north .The finding in this paper could provide a reference frame for short time climatic prediction and agricultural arrangement .