Intraseasonal oscillation of the rainfall variability over Rwanda and evaluation of its subseasonal forecasting skill

作     者：Xuan Zhou Lin Chen Janet Umuhoza Yifeng Cheng Lu Wang Ran Wang Xuan Zhou;Lin Chen;Janet Umuhoza;Yifeng Cheng;Lu Wang;Ran Wang

作者机构：Key Laboratory of Meteorological DisasterMinistry of Education(KLME)/Joint International Research Laboratory of Climate and Environmental Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)Nanjing University of Information Science and TechnologyNanjingChina College of Atmospheric ScienceNanjing University of Information Science and TechnologyNanjingChina Rwanda Meteorology AgencyKigaliRwanda 

出 版 物：《Atmospheric and Oceanic Science Letters》 (大气和海洋科学快报（英文版）)

年 卷 期：2021年第14卷第6期

页      面：60-65页

核心收录：

学科分类：07[理学] 070601[理学-气象学] 0706[理学-大气科学] 

基　　金：jointly supported by the National Key Research and Development Program of China[grant number 2019YFC1510004]and the LASG Open Project 

主　　题：Intraseasonal oscillation Rwanda Intraseasonal rainfall variability Subseasonal forecast 

摘      要：Rwanda is a landlocked country in central-eastern *** a country highly dependent on rain-fed agriculture,Rwanda is vulnerable to rainfall *** data show that there are two rainy seasons in Rwanda,i.e.,the long rainy season and the short rainy *** study mainly focuses on the dominant intraseasonal rainfall mode during the long rainy season(February-May),and evaluates the forecast skill for the intraseasonal variability(ISV)over Rwanda and its surrounding regions in a state-of-the-art dynamic *** the long rainy season,observational results reveal that the dominant intraseasonal rainfall mode in Rwanda exhibits a significant variability on the 10-25-day time ***-point-correlation analysis further unveils that the 10-25-day intraseasonal rainfall variability in Rwanda co-varies with that in its adjacent areas,indicating that the overall 10-25-day rainfall variability in Rwanda and its adjacent regions(8°S-3°N,29°-37°E)should be considered collectively when studying the dominant intraseasonal rainfall variability in *** results show that the development of the 10-25-day rainfall variability is associated with the anomalous westerly wind in Rwanda and its surrounding regions,which may trace back to a pair of westward-propagating equatorial Rossby *** on the observational findings,an ISO_rainfall_index and an ISO_wind_index are proposed for quantitatively evaluating the forecast *** ECMWF model has a comparable skill in predicting the wind index and the rainfall index,with both indices showing a skill of 18 days.