Long-term impact of urban areas on meteorological conditions: focus on cloud/rain microphysics and convection

Urban environments not only affect the warming rate over cities through the so-called urban heat island (UHI) but also induce changes in other relevant meteorological variables. This study aims to evaluate the impact that different combinations of urban, microphysics and convective parameterizations have on a number of meteorological variables, including temperature, wind, and those related to cloud/rain microphysics. Simulations were performed using the WRF model with a domain at 9km horizontal resolution centered over Prague covering central Europe for the 2008-2017 period. The urban schemes used include bulk, the single-layer urban canopy model (SLUCM), and the multilayer urban models (BEP-BEM) with a building energy model including anthropogenic heat due to air conditioning. We further consider another scenario in which the urban land use category is fully replaced by a rural one (NO URBAN). Besides, we also used two different options for the microphysics and convective schemes. These parameterizations are the Purdue and Lin and the WRF Double moment 6-class scheme for the microphysics option, and the Grell3D and the Grell and Freitas schemes for the convective scheme. Our results show that the inclusion of urban canopy schemes leads to an increase in temperature and a decrease in wind speed as well as to changes in other relevant meteorological values such as cloudiness and precipitation, which also depend on the microphysics and convective scheme used.