Integrated modelling for assessment the influence of aerosol feedbacks on a regional scale as a result of accidental wildfires and land cover changes in Ukraine

The study presents the analysis of regional atmospheric condition changes in Ukraine caused by direct and indirect aerosol effects performed by a series of simulations using the Environment – High Resolution Limited Area Model (Enviro-HIRLAM). The research is based on two case studies. The first case study includes a severe wildfire event in the Chornobyl Exclusion Zone (northern part of Ukraine) which was observed in April 2020. The second case study analyzed the influence of hypothetical total deforestation in Ukraine during the extreme heat wave and heavy rain episodes in August 2010. Enviro-HIRLAM model was run for the domain with 15-km resolution and further downscaling to 5 and 2-km resolution. The simulations include 4 running modes: reference run with no aerosol effects (CTRL); including direct (DAE), indirect (IDAE) and both (DAE+IDAE) aerosol effects. The study analyzes the aerosol impact on thermal and moisture regimes at the surface and on the model levels up to 5 km above the ground. It is emphasized the role of anthropogenic and natural processes at the surface (like wildfires, land cover changes, etc.) on the enhancing of aerosol effects during extreme and unfavorable weather conditions. This study is supported by the grants of HPC-Europa3 Transnational Access Programme for projects HPC17TRLGW IMA-WFires “Integrated Modelling for Assessment of Potential Pollution Regional Atmospheric Transport as Result of Accidental Wildfires” and HPC17ENAVF MALAWE “Integrated Modelling and Analysis of Influence of Land Cover Changes on Regional Weather Conditions/ Patterns”. The CSC - IT Center for Science Computing (Finland) is acknowledged for computational resources.