Climate projections over CORDEX Africa domain using the fifth-generation Canadian Regional Climate Model (CRCM5)

Abstract

Following the CORDEX experimental protocol, climate simulations and climate-change projections for Africa were made with the new fifth-generation Canadian Regional Climate Model (CRCM5). The model was driven by two Global Climate Models (GCMs), one developed by the Max-Planck-Institut für Meteorologie and the other by the Canadian Centre for Climate Modelling and Analysis, for the period 1950-2100 under the RCP4.5 emission scenario. The performance of the CRCM5 simulations for current climate is discussed first and compared also with a reanalysis-driven CRCM5 simulation. It is shown that errors in lateral boundary conditions and sea-surface temperature from the GCMs have deleterious consequences on the skill of the CRCM5 at reproducing specific regional climate features such as the West African Monsoon and the annual cycle of precipitation. For other aspects of the African climate however the regional model is able to add value compared to the simulations of the driving GCMs. Climate-change projections for periods until the end of this century are also analysed. All models project a warming throughout the twenty-first century, although the details of the climate changes differ notably between model projections, especially for precipitation changes. It is shown that the climate changes projected by CRCM5 often differ noticeably from those of the driving GCMs.

3-Step dynamical downscaling with empirical correction of sea-surface conditions: application to a CORDEX Africa simulation

“…A detailed description of CRCM5 is given in Hernández-Díaz et al (2013, hereinafter HD13) and Laprise et al (2013). CRCM5 is based on a limited-area configuration of the Global Environment Multiscale (GEM) model (Bélair et al 2005(Bélair et al , 2009) employed for numerical weather prediction by the Canadian Meteorological Centre (CMC).…”

“…The land-surface scheme however is changed from ISBA used in GEM for the Canadian LAnd Surface Scheme (CLASS; Verseghy 2000Verseghy , 2008 in its most recent version, CLASS 3.5. For these simulations 26 soil layers are used, reaching to a depth of 60 m as in Laprise et al (2013). Otherwise, as in HD13 and Laprise et al (2013), the standard CLASS distributions of sand and clay fields as well as the bare soil albedo values were replaced by data from the ECOCLIMAP database (Masson et al 2003).…”

“…Moreover, both CGCMs (MPI-ESM-LR and CanESM2) exhibited strong SSTs biases in tropical and equatorial Atlantic Ocean (Fig. 3 in Laprise et al 2013). The 3-step DD over the CORDEX Africa domain reveals the extent to which the modified SSTs can improve the simulation of the West African Monsoon (WAM) precipitation.…”

Evaluation of CORDEX-Arctic daily precipitation and temperature-based climate indices over Canadian Arctic land areas

“…Both the historical CMIP5 GCM-and ERAI-driven CORDEX simulations were evaluated. This allowed us to assess the RCM structural biases as well as the effect of GCM errors on the RCM simulations Laprise et al 2013). The evaluation was carried out by comparing simulated values to station records across the Canadian Arctic.…”

Dynamical downscaling with the fifth-generation Canadian regional climate model (CRCM5) over the CORDEX Arctic domain: effect of large-scale spectral nudging and of empirical correction of sea-surface temperature

“…The Canadian Regional Climate Model, version 5 (CRCM5) has contributed to the CORDEX program over three CORDEX domains so far: North America Šeparović et al 2013), Africa Laprise et al 2013) and South Asia (Alexandru and Sushama 2014). Paquin and Sushama (2014) have carried some experiments with CRCM5 over the Arctic.…”