国家自然科学基金No.41275017;公益性行业气象科研专项No.GYHY201306042,GYHY201406031;中山大学高校基本科研业务费专项No.13lgjc09;Supported by the National Natural Science Foundation of ChinaNo.41275017,the China Special Fund for Meteorological Research in the Public InterestNo.GYHY201306042,GYHY201406031and the Fundamental Research Funds for the Central UniversitiesNo.13lgjc09