宁夏高温多、少年平均环流及OLR场特征分析

Analysis on Features of Average Circulation and OLR Field During the Years with More and Less High Temperature Weather in Ningxia

利用NCEP/NCAR(1979～1999年)月平均再分析资料和OLR(1971～1999年)月平均资料,结合宁夏1960～2000年各站逐日最高气温实况资料,对宁夏高温天气的主要气候特征以及7月高温天气典型偏多年和偏少年的大气环流和OLR特征进行对比诊断分析。结果表明:宁夏高温天气偏多和偏少年中,极涡的强度及位置、大陆高压、副热带高压的强度和位置具有明显差异;中高纬地区的温度场在偏多和偏少年份也有相反的分布。不仅如此,高温天气的偏多和偏少还与低纬和热带地区大气环流变化有关。

NCEP/NCAR reanalyzed monthly average data of 1979～1999,monthly average OLR fields of 1971～1999 and daily maximum temperatures of 1960～2000 obtained from every meteorological station in Ningxia were applied to conduct a comparative diagnosis on major climate features of atmosphere circulation and OLR fields in typical years with more and less high temperature weather in July.Results show that the intensity and location of polar vortex,continent high pressure and subtropical high pressure are distinctively different in July with more and less high temperature weather,and the temperature field distributions are on contrary at middle and high latitude.And the high temperature weather is also related to variation of atmosphere at low latitude and tropical zone.