Editing IPCC:AR6/WGI/Chapter-Atlas (section)

=== Atlas.4.3 Assessment of Model Performance ===

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Model development has advanced in the world, but Africa still lags as a focus and in its contribution ( [[#James--2018|James et al., 2018]] ). None of the current generation of global climate models (GCMs) was developed in Africa ( [[#Watterson--2014|Watterson et al., 2014]] ), and the relevant processes in the continent have not been the priority for model development but treated in a one-size-fit-all approach ( [[#James--2018|James et al., 2018]] ) except for a few studies that focused on convective-permitting climate projections ( [[#Stratton--2018|Stratton et al., 2018]] ; [[#Kendon--2019|Kendon et al., 2019]] ). However, there are growing efforts to boost African climate science by running and evaluating climate models over Africa ( [[#Endris--2013|Endris et al., 2013]] ; [[#Kalognomou--2013|Kalognomou et al., 2013]] ; [[#Gbobaniyi--2014|Gbobaniyi et al., 2014]] ; [[#Engelbrecht--2015|Engelbrecht et al., 2015]] ; [[#Klutse--2016|Klutse et al., 2016]] ; [[#Gibba--2019|Gibba et al., 2019]] ).

The CMIP project previously did not result in improved performance for Africa ( [[#Flato--2013|Flato et al., 2013]] ; [[#Rowell--2013|Rowell, 2013]] ; [[#Whittleston--2017|Whittleston et al., 2017]] ) and culling ensembles based on existing metrics for Africa fails to reduce the range of uncertainty in precipitation projections ( [[#Roehrig--2013|Roehrig et al., 2013]] ; [[#Yang--2015|Yang et al., 2015]] ; [[#Rowell--2016|Rowell et al., 2016]] ), but biases over Africa are lower in CMIP6 compared to CMIP5 ( [[#Almazroui--2020c|Almazroui et al., 2020c]] ). Nonetheless, the CMIP5 ensemble has been evaluated over Africa to advance its application for climate research ( [[#Biasutti--2013|Biasutti, 2013]] ; [[#Rowell--2013|Rowell, 2013]] ; [[#Dike--2015|Dike et al., 2015]] ; [[#McSweeney--2016|McSweeney and Jones, 2016]] ; [[#Onyutha--2016|Onyutha et al., 2016]] ; [[#Wainwright--2019|Wainwright et al., 2019]] ) as has, more recently, the CMIP6 ensemble ( [[#Almazroui--2020c|Almazroui et al., 2020c]] ).

Coordinated Regional Downscaling Experiment (CORDEX) regional climate models have been widely evaluated over Africa. They capture the occurrence of the West African Monsoon jump and the timing and amplitude of the mean annual cycle of precipitation and temperature over the homogeneous sub-regions of West Africa ( [[#Gbobaniyi--2014|Gbobaniyi et al., 2014]] ), simulate eastern Africa rainfall adequately ( [[#Endris--2013|Endris et al., 2013]] ), and over southern Africa capture the observed climatological spatial patterns of extreme precipitation ( [[#Pinto--2016|Pinto et al., 2016]] ). They also effectively simulate the phasing and amplitude of monthly rainfall evolution and the spatial progression of the wet season onset over southern Africa ( [[#Shongwe--2015|Shongwe et al., 2015]] ). However, discrepancies and biases in present-day rainfall are reported over Uganda from the RCM-simulated rainfall compared to three gridded observational datasets ( [[#Kisembe--2019|Kisembe et al., 2019]] ). Specifically, they reported that the CORDEX models underestimate the annual rainfall in Uganda and struggle to reproduce the variability of the long and short rainy seasons.

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