【摘要】 为了更好地预报青藏高原及其邻近地区天气系统的发生、发展,我们进行了风场初始化方法的研究。本文比较了P—σ混合坐标下C型跳点网格的整层无辐散、各层无辐散、地转风等三种风场初始化方案,利用1979年6月2日12时—4日12时(GMT)FGCFⅡ_b资料作了试验。这三种方案初始化结果的统计分析及实例预报结果的天气学分析表明:整层无辐散方案在高原及其邻近地区优于其它方案;各层无辐散方案的动能损耗过大;地转风方案的流场在低层虽比较紊乱,但高层高度场形势预报较好。在此基础上又试验了高层采用地转风的整层无辐散的混合方案。36小时预报结果在高原地区有所改进。更多还原

【Abstract】 A study of initialization of observed wind data has been conducted recently to improve the forecast of the generation and development of weather systems over Qinghai-Xizang Plateau and its vicinity. Using the FGGE Ⅲb data of 1200 GMT 2 June 1979 as the initial input data, a comparative test is done for three kinds of initialization schemes, i.e., the mean nondivergence scheme, the scheme of nondivergent wind for each level and the geos trophic scheme.The statistical analysis and the map-discussion show that the forecast with the mean nondivergence scheme is superior to the others over Plateau and its vicinity. More serious loss of kinetic energy is found in the results of scheme of nondivergent wind for each level. The flow field simulated with the initial geostrophic wind is some-how noisy in the lower layers, though appears better than the others in the upper levels.Based on above analysis, we have tested a combined scheme which uses geostrophic wind at the upper layers and then repeats the whole procedure of mean nondivergence to the model atmosphere. The numerical simulation shows some improvements in the 36h forecast over Plateau.更多还原