山东夏季降水异常的环流特征及降尺度解释应用预测方法研究

Research on circulation characteristics of anomalous summer precipitation in Shandong and prediction by downscaling interpretation and application

基于山东省123个国家级气象观测站1961—2015年夏季降水资料、1991—2015年NCEP再分析资料,分析了山东夏季降水变化特征及其与大气环流的关系。结果表明,在山东夏季降水偏多(少)时,乌拉尔山阻塞高压偏弱(强),副热带高压偏强(弱),南亚高压偏强(弱),并且200 hPa经向风场有明显的类似丝绸之路遥相关型的波列结构。利用国家气候中心第二代海气耦合模式3月起报的未来夏季海平面气压场建立降尺度预测模型,该模型对山东夏季降水的预测符号一致率达到64%,有一定的预测能力,进一步分析发现,模式对关键区环流因子的模拟预测能力显著影响降尺度预测方法的准确率。

The variation characteristics of summer precipitation in Shandong and their relationship with atmospheric circulation are studied based on summer precipitation data of 123 national meteorological stations from 1961 to 2015 and NCEP reanalysis data from 1991 to 2015.The results indicate that when the summer precipitation in Shandong is more(less),Ural blocking high is weaker(stronger),the subtropical high is stronger(weaker),South Asia high is stronger(weaker),and an obvious wave train that resembles the Silk Road Pattern appears on the meridional wind field at 200 hPa.The downscaling prediction model is established utilizing the second generation of National Climate Center coupled ocean-atmosphere model to predict the future summer sea-level pressure from March,and the sign consistency of prediction by downscaling interpretation method and observation can reach 64%.The downscaling method has predictive ability for the ability of summer precipitation in Shandong.Further analysis shows that the simulation and prediction ability of the model on circulation factor of key region has significant influence on the skill of downscaling method.