WASCAL WRF60km with GFDL-ESM r1i1p1 forcing from the CMIP5 historical experiment

Project: West African Science Service Centre on Climate Change and Adapted Land Use - With climate change being one of the most severe challenges to Africa in the 21st century, West Africa is facing an urgent need to develop effective adaptation and mitigation measures. WASCAL (West African Science Service Centre on Climate Change and Adapted Land Use, http://www.wascal.org) is a large-scale research-focused Climate Service Centre designed to help tackle this challenge and thereby enhance the resilience of human and environmental systems to climate change and increased variability. It does so by strengthening the research infrastructure and capacity in West Africa related to climate change and by pooling the expertise of ten West African countries and Germany. Funded by the German Federal Ministry of Education and Research (BMBF), WASCAL is implemented in a collaborative effort by West African and German partners. An integral part of its climate services is the provisioning of a new set of high resolution, ensemble-based regional climate change scenarios for the region of West Africa. An ensemble approach is chosen to address model uncertainties and provide statistical estimates on possible future climate change scenarios. The ensemble is composed of three regional climate models, WRFV3.5.1, COSMO-CLM 4.18, and REGCM4. Three Earth System Models from the CMIP5 project are downscaled by each of the regional models, MPI-ESM, GFDL-ESM2M, and HadGEM2-ES for the historical period from 1980 to 2010 and for the RCP4.5 scenario from 2020 to 2050 and from 2070 to 2100. Control runs are created by downscaling the European Centre for Medium-Range Weather Forecasts ERA-Interim re-analysis from 1980 to 2014. Two sets of resolutions are made available, 60km and 12km, for a large domain covering the greater region of West Africa from 25W to 25E and 5S to 25N. Summary: This experiment uses 'CMIP5 GFDL r1i1p1 historical' forcing data for downscaling to 60km resolution by the regional model WRFV3.5.1 for the region of West Africa. 'historical' is an experiment of the CMIP5 - Coupled Model Intercomparison Project Phase 5 (https://pcmdi.llnl.gov/mips/cmip5). 3.2 historical (3.2 Historical) - Version 1: Simulation of recent past (1850 to 2005). Experiment design:https://cera-www.dkrz.de/WDCC/ui/Entry.jsp?acronym=Taylor_CMIP5_design.pdf . This experiment is divided into several time slices of 11 years. The first year of each time slice is used as a spin-up phase and should not be used in the analysis. All experiments with GFDL forcing refer to a calendar with 365 days (noleap). The 60 km resolution of this experiment is an intermediate step to the 12km downscaling WRF experiment.

项目：西非气候变化与土地利用适应科学服务中心（West African Science Service Centre on Climate Change and Adapted Land Use，WASCAL）
气候变化是21世纪非洲面临的最严峻挑战之一，西非地区亟需制定有效的适应与减缓措施。WASCAL是一家大型以研究为导向的气候服务中心，旨在应对这一挑战，进而提升人类与环境系统应对气候变化及变异加剧的韧性。该中心通过强化西非地区与气候变化相关的研究基础设施与能力，整合西非十国与德国的专业科研力量。本中心由德国联邦教育与研究部（Bundesministerium für Bildung und Forschung，BMBF）资助，由西非与德国合作伙伴联合实施。
其气候服务的核心组成部分之一，是为西非地区提供一套全新的、基于集合模拟的高分辨率区域气候变化情景。研究团队采用集合模拟方法以应对模式不确定性，并为未来可能的气候变化情景提供统计估算。该集合模拟包含3种区域气候模式：WRFV3.5.1、COSMO-CLM 4.18与REGCM4。每种区域模式均对耦合模式比较计划第五阶段（Coupled Model Intercomparison Project Phase 5，CMIP5）项目下的3个地球系统模式进行降尺度处理，分别为MPI-ESM、GFDL-ESM2M与HadGEM2-ES，模拟时段涵盖1980年至2010年的历史时期，以及典型浓度路径4.5（Representative Concentration Pathway 4.5，RCP4.5）情景下的2020年至2050年与2070年至2100年。控制试验则通过对1980年至2014年的欧洲中期天气预报中心（European Centre for Medium-Range Weather Forecasts，ECMWF）ERA-Interim再分析数据进行降尺度生成。
本数据集提供两种分辨率版本：60km与12km，覆盖的大区域范围为西经25°至东经25°、南纬5°至北纬25°的西非全域。

试验摘要：
本试验采用“CMIP5 GFDL r1i1p1 historical”强迫数据，利用区域模式WRFV3.5.1对西非地区开展60km分辨率的降尺度模拟。其中“historical”是CMIP5（耦合模式比较计划第五阶段，https://pcmdi.llnl.gov/mips/cmip5）的一类试验，即3.2 Historical（3.2历史试验）版本1：用于模拟近现代时期（1850年至2005年）。试验设计详见：https://cera-www.dkrz.de/WDCC/ui/Entry.jsp?acronym=Taylor_CMIP5_design.pdf。本试验被划分为若干个11年的时间切片，每个时间切片的首年作为自旋调整（spin-up）阶段，不应纳入数据分析。所有采用GFDL强迫的试验均使用365天历法（noleap，即无闰年历法）。本试验的60km分辨率降尺度模拟，是后续12km分辨率WRF试验的前置中间步骤。