Title
Benefits of simulating precipitation characteristics over Africa with a regionally-coupled atmosphere–ocean model
Date Issued
01 January 2022
Access level
open access
Resource Type
journal article
Author(s)
Publisher(s)
Springer Science and Business Media Deutschland GmbH
Springer Nature
Abstract
High-quality climate information at appropriate spatial and temporal resolution is essential to develop and provide tailored climate services for Africa. A common method to produce regional climate change data is to dynamically downscale global climate projections by means of regional climate models (RCMs). Deficiencies in the representation of the sea surface temperatures (SSTs) in earth system models (ESMs) and missing atmosphere–ocean interactions in RCMs contribute to the precipitation bias. This study analyzes the influence of the regional atmosphere–ocean coupling on simulated precipitation and its characteristics over Africa, and identifies those regions providing an added value using the regionally coupled atmosphere–ocean model ROM. For the analysis, the MPI-ESM-LR historical simulation and emission scenario RCP8.5 were dynamically downscaled with ROM at a spatial resolution of 0.22° × 0.22° for the whole African continent, including the tropical Atlantic and the Southwest Indian Ocean. The results show that reduced SST warm biases in both oceans lead to more realistic simulated precipitation over most coastal regions of Sub-Saharan Africa and over southern Africa to varying degrees depending on the season. In particular, the annual precipitation cycles over the coastal regions of the Atlantic Ocean are closer to observations. Moreover, total precipitation and extreme precipitation indices in the coupled historical simulation are significantly lower and more realistic compared to observations over the majority of the analyzed sub-regions. Finally, atmosphere–ocean coupling can amplify or attenuate climate change signals from precipitation indices or even change their sign in a regional climate projection.
OCDE Knowledge area
Investigación climática
Subjects
Scopus EID
2-s2.0-85132135499
Source
Climate Dynamics
ISSN of the container
09307575
Sponsor(s)
The authors would like to thank the Copernicus Climate Change Service (C3S) Climate Data Store (CDS) for providing the ERA5 reanalysis data set ( https://climate.copernicus.eu/climate-reanalysis ). We acknowledge that this work contains modified Copernicus Climate Change Service Information and neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains. In addition, we would like to thank the European Centre for Medium-Range Weather Forecasts (ECMWF) for providing the ERA-Interim reanalysis data set ( https://www.ecmwf.int/en/forecasts/datasets/reanalysis-datasets/era-interim ). We acknowledge the Global Precipitation Climatology Centre (GPCC) ( https://www.dwd.de/EN/ourservices/gpcc/gpcc.html ), the Climate Hazards Center of the University of California ( https://www.chc.ucsb.edu/data/chirps ) and the Climatic Research Unit of the University of East Anglia ( https://sites.uea.ac.uk/cru/ ) for the provision of their observational precipitation data sets. NOAA High Resolution SST data was provided by the NOAA/OAR/ESRL PSL, Boulder, Colorado, USA, from their web site at https://downloads.psl.noaa.gov/Datasets/noaa.oisst.v2.highres/ . The model simulations were performed at the German Climate Computing Center (Deutsches Klimarechenzentrum, DKRZ) in Hamburg. Dmitry Sein was supported in the framework of the state assignment of the Ministry of Science and Higher Education of Russia (№ FMWE-2021-0014). Finally, the authors would like to thank the anonymous reviewers and the colleagues of the Climate Service Center Germany (GERICS) for their constructive support.
Sources of information:
Directorio de Producción Científica
Scopus