基于CFSv2对夏季西太平洋副高逐日预测能力的检验评估

Testing and Assessment of Capabilities of Day-to-Day Predicting of Summertime West Pacific Subtropical High Based on CFS v2

利用NCEP的气候预报系统第2版（CFSv2）提供的2000-2010年夏季逐日500hPa位势高度历史回报试验结果，通过均方根误差分析等方法，检验评估了该系统对夏季500hPa西太平洋副高的预测能力，发现CFSv2对夏季西太平洋500hPa位势高度场的整体相关性较高。CFSv2对副高西脊点和脊线位置的1～7d的预报准确率存61．8％以上，对副高面积指数、强度指数以及北界位置6～42h预报时效的预报准确率在60％以上。此外，对副高面积指数、强度值和北界位置的预测结果作功率谱分析，得出CFSv2对500hPa副高强度指数1～7d预测能力的变化在6—8月存在着显著的2．2～3．3d的变化周期。

Using historical hindcasts of day-to-day 500-hPa geopotential heights from 2000 to 2010 given by the second version of Climate Forecasting System of NCEP （CFSv2） and with the methods such as the root mean square analysis, we tested and assessed its capabilities of predicting summertime day-to-day 500- hPa geopotential heights, with the finding that CFSv2 has high overall correlation with the geopotential field for the same level. Its accuracy is more than 61.8% in predicting the westernmost point and position of the subtropical high ridge one to seven days ahead and more than 60% in predicting the area and intensity indexes as well as the position of the northern boundary of the subtropical high for the coming 6 - 42 h. Besides, CFSv2 varies with a significant period of 2.2 to 3.3 d in June to August when it is used to predict the intensity index at 500 hPa.