How are air and land temperatures affected by the horizontal resolution and the bulk urban parametrisation in WRF model simulations over the eastern Mediterranean and the Middle East?

Urbanization alters land surface properties and the local surface energy balance and, therefore, land and near surface air temperature. Urban morphology and processes are represented in climate models using urban land-surface models with varying levels of complexity, which parameterise the effects of urban environments on surface fluxes without representing buildings explicitly.

This study focuses on the eastern Mediterranean and the Middle East (EMME) area over which the effect of urban parameterisation and resolution difference on simulated 2-meter air and land surface temperatures is investigated. Two high-resolution simulations at 16 km and 4 km are performed over the EMME domain using the Weather Research and Forecasting (WRF) model coupled with NoahMP land surface scheme for the period of 2000-2002. The bulk urban parameterisation scheme is implemented, which assigns fixed values for land properties such as surface albedo, roughness length etc., appropriate for the resolved urban areas. Focusing on several cities of the region of interest for the summer season (June-July-August, JJA), the effect of the model horizontal resolution and the grid-box land type on air (minimum and maximum) and land temperatures is examined. The temperature difference of the urban-characterised grid-boxes compared to their rural surroundings is also studied. Station (Integrated Surface Dataset - ISD) and satellite (MODIS-TERRA) observations together with reanalysis data (ERA5-LAND) are used for the evaluation of the simulation output.