Convection‐permitting modeling with regional climate models: Latest developments and next steps

Abstract

Approximately 10 years ago, convection-permitting regional climate models (CPRCMs) emerged as a promising computationally affordable tool to produce fine resolution (1-4 km) decadal-long climate simulations with explicitly resolved deep convection. This explicit representation is expected to reduce climate projection uncertainty related to deep convection parameterizations found in most climate models. A recent surge in CPRCM decadal simulations over larger domains, sometimes covering continents, has led to important insights into CPRCM advantages and limitations. Furthermore, new observational gridded datasets with fine spatial and temporal ($1 km; $1 h) resolutions have leveraged additional knowledge through evaluations of the added value of CPRCMs. With an improved coordination in the frame of ongoing international initiatives, the production of ensembles of CPRCM simulations is expected to provide more robust climate projections and a better identification of their associated uncertainties. This review paper presents an overview of the methodology to produce CPRCM simulations and the latest research on the related added value in current and future climates. Impact studies that are already taking advantage of these new CPRCM simulations are highlighted. This review paper ends by proposing next steps that could be accomplished to continue exploiting the full potential of CPRCMs.

Evaluation of the convection-permitting regional climate model CNRM-AROME41t1 over northwestern Europe

“…Despite the satisfactory performance of CNRM-AROME, this model suffers of systematic biases, also common to many other CPRCMs (Ban et al 2021), that could be reduced such as the wet bias in winter and spring, the warm bias in summer, and the overestimation of the amplitude of the diurnal cycle of precipitation in summer. CPRCMs are still in their infancy (Lucas-Picher et al 2021) and faces many challenges in the developments of their land-surface scheme and sub-kilometer scale processes that still need to be parametrized, with existing parameterization schemes often requiring further development or to be adapted for specific use in CPRCMs (Kendon et al 2021). The model presented in this paper is the first operational CPRCM developed at Meteo-France.…”

“…Another feature that is generally improved by CPRCMs is the summer precipitation diurnal cycle (Argueso et al 2016;Brisson et al 2016;Berthou et al 2020;Lucas-Picher et al 2021) illustrated in Fig. 12 for the four climatic regions of interest.…”

“…However, as for their GCMs counterpart, conventional RCMs using grid meshes of 10 km and above suffer from the use of deep convection parameterization that is a known source of modeling uncertainty (Kendon et al 2012;Fosser et al 2020). Recent progress in high performance computing and in efficient non-hydrostatic atmospheric dynamical cores led to the development of convection-permitting RCMs (CPRCM) capable to perform long-climate simulations with grid meshes finer than 4 km in which deep convection can be explicitly simulated, allowing the removal of deep convective parameterizations (Leutwyler et al 2016;Lucas-Picher et al 2021). Following those developments, over the last years, many CPRCMs have emerged in different climate research institutes (Prein et al 2013;2015;Ban et al 2021;Belusic et al 2020;Coppola et al 2020Coppola et al , 2021Pichelli et al 2021).…”

Characteristics of precipitation extremes over the Nordic region: added value of convection-permitting modeling

“…Due to increased computer capacity, running convectionpermitting regional climate models (CPRCMs) with explicit deep convection and a high grid resolution (typically < 4 km) has recently become affordable on a climatic scale (see, e.g., Coppola et al, 2020;Lucas-Picher et al, 2021;Pichelli et al, 2021). Since short-duration extreme events are often associated with smaller-scale spatial structures, there is a strong indication that these events are better represented using an increased model resolution.…”

Characteristics of precipitation extremes over the Nordic region: added value of convection-permitting modeling

“…Due to increased computer capacity, running convection-permitting regional climate models (CPRCMs) with explicit convection and a high grid resolution (typically < 4 km) has recently become affordable on a climatic scale (see e.g., Coppola et al, 2020;Lucas-Picher et al, 2021;Pichelli et al, 2021). Since short-duration extreme events are often associated with smaller-scale spatial structures, there is a strong indication that these events are better represented using an increased model resolution.…”