摘要
利用1981-2019年NCEP/NCAR再分析资料和观测降水资料,对山东5月降水多(少)雨年环流特征进行分型,分析前期海温影响大气环流进而影响降水的过程。结果表明:典型多(少)雨年,亚洲中高纬环流呈“-、+”(“+、-”)距平分布,盛行纬(经)向环流,东亚大槽偏弱(强)。前期冬春季黑潮区和热带印度洋海温是影响山东5月降水的关键外强迫因子,黑潮区海温偏暖(冷)时,其上空500 hPa高度场为明显正(负)距平,低层风场呈现异常反气旋(气旋),山东受异常东南风(偏西风)控制,加强(削弱)了水汽输送,利于降水偏多(少)。热带印度洋偏暖年,山东地区500 hPa高度场上表现为西低东高,低层处于异常反气旋后部的东南气流中,这与典型多雨年的环流特征基本一致,印度洋偏冷年对应环流特征与偏暖年大致相反。
Using the NCEP/NCAR Reanalysis and observed precipitation data from 1981 to 2019,the circulation characteristics of more(less)rainfall year in May in Shandong are classified,and the process of previous sea surface temperature(SST)affecting atmospheric circulation and further affecting precipitation is analyzed.The results show that in the typical more(less)rainfall year,the distribution of mid-high latitudinal circulations in Asia is“-,+”(“+,-”).With dominated latitudinal(meridional)circulations,the east Asian trough is weak(strong).Early winter Kuroshio area and the tropical Indian Ocean SST are the key external forced factors that affects the precipitation in May.When the Kuroshio area SST is warm(cold),the 500 hPa height field is significant positive(negative)anomaly distribution,and the low-level wind field renders anomalous anti-cyclonic(cyclonic).Controlled by the southeast wind anomalies(westerly)in Shandong,the water vapor transport is strengthened(weakened),which is beneficial to more(less)precipitation.In a warm year of the tropical Indian Ocean,the 500 hPa height field in Shandong region is low in the west and high in the east,and the lower layer is dominated by the southeast airflow behind the anomalous anticyclone,which is basically consistent with the circulation characteristics of a typical more rainfall year,while the circulation in a cold year of the Indian Ocean is roughly opposite.
作者
伯忠凯
胡桂芳
徐玮平
BO Zhongkai;HU Guifang;XU Weiping(Key Laboratory for Meteorological Disaster Prevention and Mitigation of Shandong,Jinan 250031,China;Shandong Climate Center,Jinan 250031,China)
出处
《海洋气象学报》
2021年第2期119-125,共7页
Journal of Marine Meteorology
基金
山东省气象局科研项目(2017sdqxm03,SDYBY2019-02,2020SDQN03)。
关键词
山东5月降水
异常环流型
黑潮区海温
热带印度洋海温
precipitation in May in Shandong
anomalous circulation pattern
SST in Kuroshio
SST of the tropical Indian Ocean
