Comparison of Global Ammonia and Ammonium Nitrate Budgets between the Models EMEP and UKCA-CLASSIC
Abstract
Large increases globally in fertiliser use and livestock have resulted in more reactive nitrogen being present in the Earth System, with effects including eutrophication and hypoxic zones, acidification, biodiversity loss, climate change, destruction of the ozone layer, and human health effects from aerosols and contaminated drinking water. Ammonia is a critical species in the nitrogen cycle as it volatilises from fertiliser and manure, and it is also the principal alkaline gas in the atmosphere. It therefore plays an important role in atmospheric chemistry, reacting with sulphuric and nitric acids to form ammonium aerosols, which serve as cloud condensation nuclei and negatively impact human health. Anthropogenic ammonia emissions are increasing rapidly on a global scale, and are set to continue to do so this century due to increasing global temperatures, animal feed, and food production. Sinks for ammonia and ammonium nitrate are strongly influenced by weather as precipitation patterns drive wet deposition. Weather and climate therefore affect the atmospheric lifetimes of ammonia and ammonium nitrate which contribute to regional and temporal differences in air quality. We present a comparison of global and regional ammonia and ammonium nitrate budgets as simulated by two global atmospheric models: the chemistry-climate model UKCA coupled to the Unified Model with the aerosol scheme CLASSIC, and the atmospheric chemistry transport model EMEP-WRF which is driven by meteorology from the WRF model. We compare global distributions, deposition fluxes and lifetimes of ammonia and ammonium nitrate, quantifying the important processes that control reduced nitrogen in the atmosphere and discuss regional and seasonal differences in the atmospheric budgets.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMA074...02S
- Keywords:
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- 3322 Land/atmosphere interactions;
- ATMOSPHERIC PROCESSES;
- 0402 Agricultural systems;
- BIOGEOSCIENCES;
- 0414 Biogeochemical cycles;
- processes;
- and modeling;
- BIOGEOSCIENCES;
- 0426 Biosphere/atmosphere interactions;
- BIOGEOSCIENCES