Assessment of physical schemes for WRF model in convection-permitting mode over southern Iberian Peninsula

TL;DR

This study evaluates how different physical schemes in the WRF model affect precipitation and temperature simulations over southern Iberian Peninsula, identifying optimal configurations for convection-permitting modeling in complex terrain.

Contribution

It provides a comprehensive assessment of 12 physics scheme combinations in WRF for convection-permitting simulations over Andalusia, highlighting the most suitable configurations for regional climate modeling.

Findings

GF and OFF schemes outperform others in precipitation simulation.

WSM7-GF configuration is most suitable for Andalusia.

THOMPSON microphysics performs better in high mountain areas.

Abstract

Convection-permitting models (CPMs) enable the representation of meteorological variables at horizontal high resolution spatial scales (higher than 4 km), where convection plays a significant role. Physical schemes need to be evaluated considering factors in the studied region such as orography and climate variability. This study investigates the sensitivity of the WRF model as CPM to the use of different physics schemes on Andalusia, a complex orography region in southern Iberian Peninsula (IP). A set of 1-year WRF simulations was completed based on two one-way nested domains: the parent domain (d01) spanning the entire IP with 5 km spatial resolution and the nested domain (d02) for the region of Andalusia at 1 km of spatial resolution. 12 physic schemes were examined from combinations of microphysics (MP) schemes including THOMPSON, WRF single moment 6-class (WSM6), and WRF single moment 7-class (WSM7), and different options for the convection in d01, the Grell 3D (G3), Grell-Freitas (GF), Kain-Fritsch (KF), and deactivated cumulus parameterization (OFF). The simulated precipitation and 2-m temperature for the year 2018, a very wet year, were compared with observational datasets to determine the optimal WRF configuration, including point-to-point and station-point comparisons at different time aggregations. In general, greater differences were shown when comparing the results of convection schemes in d01. Simulations completed with GF or OFF presented better performance compared to the reference datasets. Concerning the MP, although THOMPSON showed a better fit in high mountain areas, it generally presents a worse agreement with the reference datasets. In terms of temperature, the results were very similar and, therefore, the selection of the best configuration was based mainly on the precipitation results with the WSM7-GF scheme being suitable for Andalusia region.