Nitrogen cycling in land-atmosphere: soil microbiological processes, surface gases flux, and atmospheric impacts (co-sponsored by ILEAPS) 
Convener: Dianming Wu  | Co-convener: Ming Chang 
Exchange of nitrogen gases between land and atmosphere are strongly affecting Earth’s atmospheric composition, air quality, climate change and human health. Atmospheric dinitrogen can be fixed by symbiotic nitrogen-fixers or free-living microbes, and further be converted to nitrite and nitrate through nitrification process. During nitrogen transformation in soil, various nitrogen gases are released to atmosphere as intermediate or by-products, for example nitrous acid (HONO), nitric oxide (NO), nitrogen dioxide (NO2), nitrous oxide (N2O) and ammonia (NH3). These reactive nitrogen gases involve in chemical reactions with ozone, volatile organic compounds, free radicals as well as aerosols, and further impact on air quality. Parts of these oxidised nitrogen (NO, HNO3 and NO2) and reduced N (NHx) are deposited in land surface by dry and wet deposition, which might in one hand clean the air, and in other hand influence nitrogen cycling in soil.
This session seeks to link soil microbiological nitrogen processes and surface nitrogen gases flux with air quality and atmospheric chemistry. It is open to a wide range of studies including methods development and application of new devices, laboratory incubation and field campaigns, process and model studies. Contributions from recent studies on modelling gases flux on air quality are especially encouraged.