A Model-based Investigation of Climate Variability and Climate Change: Focus on the West African Monsoon System

该项目将根据对哥伦比亚大学气候系统研究中心区域模式第3版（RM 3）模拟的分析，评估西非夏季风的气候变率和气候变化。研究人员将（i）确定RM 3的最佳配置，以模拟预测西澳大利亚州气候变化，（ii）调查西澳大利亚州季风爆发和非洲东风波活动的年际变化，以及它们如何与干旱相关，（iii）计算西澳大利亚州降水，温度和季风爆发日期的趋势。世纪的气候变化模型预测将受到几个全球气候模型的影响，分别针对两种温室气体排放情景。将在非洲上空0.44°（~50公里）网格上对2011-2040年和2041-2070年两个30年期的RM 3气候预测进行分析，并将这些结果与1981-2010年基期的平行模拟结果进行比较。结果将在一项新的国际合作中分享，即联合国世界气候研究项目（WCRP）倡议的协调区域气候降尺度实验（CORDEX）。 这项工作将提供更可靠的预测西澳气候趋势，在预测水的可用性将如何在整个世纪由目前的气候模型演变的大的不确定性。它将为当代和未来气候提供RM 3区域模式模拟的第一个连续多年气候学。关于季风爆发和非洲东风波分析的拟议研究将推动季节预报技术的发展。参加WCRP CORDEX将促进区域范围内分析气候变化的科学。从更广泛的影响角度来看，该项目将有助于实现CORDEX的目标，即加强全球气候建模者、缩小尺度群体和最终用户之间的互动和沟通，以更好地支持有利于非洲弱势人口的影响/适应活动。由CORDEX存档的RM 3模拟结果将为模型的相互比较研究提供数据。模型开发成果将与尼日尔尼亚美的非洲气象应用促进发展中心分享，并用于推广非洲气象应用促进发展中心RM 3天气和气候指导模拟，该模拟将提供给非洲各地的用户。

The project will assess climate variability and climate change of the West Africa (WA) summer monsoon, based on the analysis of simulations of Regional Model version #3 (RM3) of the Columbia University Center for Climate Systems Research. The investigators will (i) determine the optimum configuration of the RM3 for simulating projections of WA climate change, (ii) investigate the interannual variability of WA monsoon onset and African easterly wave activity and how they relate to droughts, and (iii) compute trends in WA precipitation, temperature and monsoon onset date. Model climate change projections during the 21st century will be forced by several global climate models, for each of two greenhouse gas emissions scenarios. RM3 climate projections will be analyzed on a 0.44° (~50 km) grid over Africa for two 30-year periods, 2011-2040 and 2041-2070 by comparing these results to a parallel simulation for a base period, 1981-2010. Results will be shared in a new international collaboration, a COordinated Regional climate Downscaling Experiment (CORDEX), an initiative of the World Climate Research Project (WCRP) of the United Nations. This work will provide more credible projections of WA climate trends, given large uncertainties in projecting how water availability in WA will evolve throughout the 21st century by current climate models. It will provide the first continuous multi-year climatologies of RM3 regional model simulations, for the contemporary and future climate. The proposed research on monsoon onset and on the analysis of African easterly waves will advance the development of seasonal forecasting techniques. The participation in WCRP CORDEX will advance the science of analyzing climate change on a regional scale. From the perspective of broader impacts, this project will contribute to the CORDEX objective of greater interaction and communication between global climate modelers, the downscaling community and end-users, to better support impact/adaptation activities benefiting Africa's vulnerable population. RM3 simulation results archived by CORDEX will provide data for model intercomparison studies. Model development achievements will be shared with the African Center of Meteorological Applications for Development (ACMAD) in Niamey, Niger, and applied to promote ACMAD RM3 weather and climate guidance simulations, which are made available to users throughout Africa.