| Abstract |
Five regional climate change projections conducted with the regional climate model REMO for the CORDEX-Africa domain (entire African continent).
INPUT DATA: In order to define the specific set of GCM simulations, to be downscaled, analyses of the full multi-model multi-scenario ensemble of GCM projec-tions from the CMIP5 database, as well as the sub-ensemble of global projections already downscaled within the CORDEX AFRICA initiative, were conducted. In total 78 climate projections from different GCMs and emission scenarios (RCP2.6, RCP4.5, RCP8.5) were analysed. For each RCP, the mean changes for temperature and precipitation over southern Africa were calculated for the far-future (2071-2100), respective to refer-ence period (1971-2000).
To obtain an overview of the projected temperature and precipitation changes from all global mod-el projections, the results of these simulations were merged into an annual scatterplot of mean changes, as depicted on the right. Thereby, each dot represents one GCM simulation; the coloured symbols indicate the global climate projections, which were already downscaled by RCMs from dif-ferent GCMs and different scenarios. The specific GCM simulations, which were identified to be downscaled by the regional climate model REMO, are marked by black framed symbols.
FINDINGS: The results depicted in the attached scatterplot show that the already downscaled global climate projections cover a wide range of climate change signals for the medium (RCP4.5) and high emission scenario (RCP8.5), but only a small number of downscaled global climate projections are available for the low emission scenario (RCP2.6), which were therefore in the focus of our downscaling activity.
Meanwhile, the identified five climate projections have al-ready been downscaled by the regional climate model REMO and have been made available at the Earth System Grid Feder-ation (ESGF).
The Figure depicts the projected precipitation change from REMO for the DJF season for the end of the century (2070-2099), respective to the reference period (1971-2000). In addition, the five new simulations, conducted within the SASSCAL project (framed in red) are included, as well as four already existing REMO projections. With respect to SASSCAL, the predominant patterns of projected change in DJF (December, January, February) precipitation tend towards a decrease in the region, encompassing southern Angola, Zambia, Namibia and Botswana, whereas for the south-eastern parts of South Africa and central Angola, an increase is projected. |
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