THE OPTIMAL SETTINGS FOR THE ONLINE-INTEGRATED MODEL ENVIRO-HIRLAM IN ORDER TO SIMULATE THE ATMOSPHERE-CHEMISTRY INTERACTION FOR THE UKRAINIAN TERRITORY

Abstract

The necessity of studying complicated feedbacks in the atmosphere and their further implementation in numerical models caused the development of online-integrated modelling. Due to the requirements of huge computer resources, this type of modelling is still not broadly available in Ukraine. The paper presents the analysis of optimal settings and input data towards the use of the online-integrated model Enviro-HIRLAM for the Ukrainian territory. Enviro-HIRLAM could be used to simulate the complicated atmosphere-chemistry interaction and include the role of direct and indirect aerosol effects on the atmospheric processes. Based on the numerous simulations using Enviro-HIRLAM while conducting two HPC-Europa3 projects, the optimal settings and input data for the Ukrainian territory were found. It is possible to define standard boundaries for a domain covering the entire Ukrainian territory with 5-km horizontal resolution. This domain does not depend on prevailing synoptic processes because it is used as a downscaling from the 15-km resolution domain, which covers large territories and considers atmospheric circulation. Further downscaling to 2 km and 1.5 km horizontal resolution allows studying the urbanization effects on the atmosphere. The paper describes settings which depend on available computer resources: dynamic time step, number of tasks and nodes, number of sub-domains, etc. We present the possible datasets which could be used for meteorological and atmospheric composition initial and boundary conditions for the Ukrainian territory. Moreover, the possible land-use/ land cover datasets and emission inventories are also given. Overall, this setting and input data allow users to run Enviro-HIRLAM using modes which include direct, indirect, or both (direct + indirect) aerosol effects. However, the control run is preferable for result comparison.