陕西省冬季典型湿冷型与干暖型气候对比分析

The comparative analysis between the typical wet cold climate and the typical warm dry climate in winter in Shaanxi Province

目的通过陕西冬季历史典型湿冷型气候与典型干暖型气候的对比分析,为冬季的短期气候预测提供思路。方法采用气候统计诊断分析及天气气候动力学分析方法。结果典型湿冷型与干暖型气候在环流背景、海平面气压场、低层风场等方面表现出几乎相反的特征。结论典型湿冷型500 hPa乌拉尔山阻塞高压、咸海低槽长时间维持,青藏高原低值系统活跃,咸海低槽分裂冷空气与暖湿气流在陕西交汇,蒙古高压偏强,伴随有强冷空气南下;典型干暖型500 hPa欧亚地区中高纬度为两槽一脊型,欧洲西北部、鄂霍茨克海分别为一低槽,西伯利亚至巴尔喀什湖为强大的高压脊,形成"西高东低"的环流形势,蒙古高压系统偏弱。

Aim To analyze climatic causes between the situation in winter of historic typical wet cold pattern and that of historic typical dry warm pattern so as to provide basis of short-term climatic trend forecast in winter.Methods Use the climatic statistical diagnosis analysis and climatic dynamics analysis method.Results Typical wet cold pattern and typical dry warm pattern in winter have contrary features in the circulation situation,surface pressure field,the horizontal wind field at lower layer and so on.Conclusion The typical wet cold pattern has the 500hPa general circulation characteristics of the long stable existence of the blocking high over Ural mountain and Aral Sea low trough,the activity of lower pressure in Tibetan Plateau,Aral sea low trough splitting cold sir converged with warm humid air in Shaanxi Province,stronger Mongolia high,accompanying continuous southward intrusion of cold air.The typical warm dry pattern has 500hPa general circulation features of two troughs one ridge distribution in mid-latitude Europe and Asia,low trough over the northwest Europe and Okhotsk,stronger pressure ridge over Siberia and Balkhash,which formed ＂high east low west＂ circulation situation,weaker Mongolia high-pressure system.