Assessment of Seasonal Rainfall Prediction in Ethiopia: Evaluating a Dynamic Recurrent Neural Network to Downscale ECMWF-SEAS5 Rainfall  

作　　者：Abebe KEBEDE Kirsten WARRACH-SAGI Thomas SCHWITALLA Volker WULFMEYER Tesfaye ABEBE Markos WARE 

机构地区：[1]Hawassa University College of Agriculture,P.O.Box 05,Hawassa,Ethiopia [2]Institute of Physics and Meteorology,University of Hohenheim,P.O.Box 70599,Stuttgart,Germany [3]Arba Minch University Water Institute of Technology,Faculty of Meteorology and Hydrology,P.O.Box 21,Arba Minch,Ethiopia

出　　处：《Advances in Atmospheric Sciences》2024年第11期2230-2244,共15页大气科学进展（英文版）

基　　金：the funding provided by the “German–Ethiopian SDG Graduate School: Climate Change Effects on Food Security (CLIFOOD)”, established by the Food Security Center of the University of Hohenheim (Germany) and Hawassa University (Ethiopia);provided by the German Academic Exchange Service (DAAD) through funds from the Federal Ministry for Economic Cooperation and Development (BMZ)。

摘　　要：Seasonal rainfall plays a vital role in both environmental dynamics and decision-making for rainfed agriculture in Ethiopia, a country often impacted by extreme climate events such as drought and flooding. Predicting the onset of the rainy season and providing localized rainfall forecasts for Ethiopia is challenging due to the changing spatiotemporal patterns and the country's rugged topography. The Climate Hazards Group Infra Red Precipitation with Station Data(CHIRPS), ERA5-Land total precipitation and temperature data are used from 1981–2022 to predict spatial rainfall by applying an artificial neural network(ANN). The recurrent neural network(RNN) is a nonlinear autoregressive network with exogenous input(NARX), which includes feed-forward connections and multiple network layers, employing the Levenberg Marquart algorithm. This method is applied to downscale data from the European Centre for Medium-range Weather Forecasts fifth-generation seasonal forecast system(ECMWF-SEAS5) and the Euro-Mediterranean Centre for Climate Change(CMCC) to the specific locations of rainfall stations in Ethiopia for the period 1980–2020. Across the stations, the results of NARX exhibit strong associations and reduced errors. The statistical results indicate that, except for the southwestern Ethiopian highlands, the downscaled monthly precipitation data exhibits high skill scores compared to the station records, demonstrating the effectiveness of the NARX approach for predicting local seasonal rainfall in Ethiopia's complex terrain. In addition to this spatial ANN of the summer season precipitation, temperature, as well as the combination of these two variables, show promising results.

关 键 词：STATION PREDICTION DOWNSCALING artificial neural networks RAINFALL 

分 类 号：P457.6[天文地球—大气科学及气象学]