Coupled modeling studies over East Asia during the KORUS-AQ field campaign

We use intense observations during the 2016 Korea-US Air Quality Field Study (KORUS-AQ) and a WRF-Chem modeling system configured over East Asia, which includes land-atmosphere and aerosol-chemistry-meteorology interactions, to investigate the benefits of satellite (land surface, weather, and atmospheric composition) data for understanding and enhancing WRF-Chem performance at process level via evaluating and/or constraining the model’s chemical initial/boundary conditions, meteorological fields, and sectoral emissions. Applications are conducted to address the following topics: 1) impacts of transboundary transport from outside of the East Asia domain and regional transport from China to the Korean Peninsula on carbon monoxide pollution in South Korea during selected episodes; 2) impacts of anthropogenic emissions of nitrogen oxides from urban and shipping sources on aerosol fields as well as their feedbacks to meteorological conditions and terrestrial ecosystem productivity over East Asia; and 3) soil moisture controls on spatiotemporal variability of nitrous acid and reactive nitrogen via directly regulating soil emissions as well as indirectly adjusting homogeneous/heterogeneous reactions and other processes. These applications all utilize products or/and modeling tools (e.g., CAMS, WRF-Chem) related to the new WMO initiative Global Air Quality Forecasting and Information System. They are in line with carbon-cycle- and nitrogen-cycle-related “ecosystem service” specified in the “WMO Global Atmosphere Watch Implementation Plan: 2016-2023”. Their implications for future applications will be discussed in relation to the recently launched GEMS which monitors East Asia as well as anticipated missions focusing on North America such as TEMPO and TRACER-AQ.