宁夏近44年水汽时空分布及环流差异特征分析  

Characteristics of Spacial-temporal Distribution of Water Vapor and Circulation Difference in Ningxia in the Past 44 Years

作　　者：陈楠[1] 陈豫英[1] 彭维耿 邵建[1] 

机构地区：[1]宁夏气象防灾减灾重点实验室,银川750002 [2]宁夏民航气象台,银川750021

出　　处：《干旱区资源与环境》2008年第7期49-54,共6页Journal of Arid Land Resources and Environment

基　　金：科技部社会公益研究专项(2004DIB3J121)"宁夏气候对全球气候变化的响应及其机制";宁夏自然科学基金(NZ0648)资助

摘　　要：利用NCEP/NCAR(1961-2004年)月平均再分析资料,对宁夏水汽含量(通量)的年际、年代际演变特征及不同区域和不同季节的分布特征进行分析;同时,结合同期宁夏24个气象站降水实况资料,通过对夏季水汽输送偏多年和偏少年环流差异特征的合成对比诊断分析,结果表明:1961年以来,宁夏水汽含量呈明显减小趋势,2001年后有所增加,中部干旱带水汽含量最小,固原市水汽含量最大;从60年代到70年代中期,不同区域纬向水汽通量总体为增加趋势,之后,均在波动中减少;引黄灌区和固原市60年代到70年代经向水汽通量有所增加,之后显著减小,中部干旱带近40多年经向水汽通量为逐渐减少趋势。同时,水汽输送偏多年,宁夏处于东高西低的环流背景下,河套地区受纬向西风控制,南风偏强,且从太平洋到孟加拉湾上有较大的水汽由南向北输送;水汽输送偏少年,河套地区处于平直气流里,东风气流较强,水汽输送较偏多年显著偏弱。NCEP/NCAR（ 1961-2004Y） monthly average reanalysed data was used to analysis the annual and decadal variation of evolutive characteristics of water vapor content and flux and seasonal distributed characteristics; Diagnosis about circulation difference characteristics were contrasted between years in which there were more water vapor transfer and less. The results indicated that the water vapor content was obviously declined since 1961 and increased since 2001. Guyuan has the most content and the arid belt in middle has the least. From 1960s to the medium of 1070s the trends of zonal water vapor flux have been generally positive and undulatorily reduced later, and the longitude water vapor flux of Yellow River diversion irrigated areas and Guyuan increased and obviously reduced later as the trends of the middle arid belt have been negative. On the other hand, in years when therere more water vapor transfer Ningxia is under the ＂high east and low west＂ circulation and the mid - reaches of the Yellow River is under the westerly zonal circulation, and then south wind is stronger than normal so that there are more vapor transfer from Pacific to Bay of Bengal, which transports from south to north; and in years when there re less water vapor transfer Mid - reaches of the Huanghe River is under the straight zonal circulation, and then easterly is stronger so that there are distinct weaker vapor transfer than normal.

关 键 词：水汽含量(通量) 环流 分析 宁夏 

分 类 号：P426[天文地球—大气科学及气象学]