surfatm : a model combining the surface energy balance and the bi-directional exchanges of pollutant to quantify the deposition and the emission of ammonia at the field scale.
Abstract
A knowledge of the exchanges between the terrestrial surface and the atmosphere is essential to quantify the emission and the deposition of the gaseous pollutants in the rural and natural areas. The << SURFATM >> model results from the coupling between a model of energy balance and a bi-directional model for ammonia exchanges. The general scheme we used to represent the mass and energy exchange allows to separate the flux from the soil from that from the vegetation. As parameterised for the ammonia exchanges, this coupled model allows to calculate the ammonia flux between the surface and the atmosphere at the field scale, by using the classical micrometeorological inputs (net radiation, wind speed, air temperature, air vapour pressure) and the atmospheric ammonia concentration. The database used to validate the model comes from the European project GRAMINAE. Model simulation results show a good agreement with the measurements for the various experimental conditions of the GRAMINAE experiment in Braunschweig (Germany). Despite of the simplicity of the scheme used to represent the soil and the vegetation, the model was able to explain the bi-directional nature of the flux. Sensitivity analysis of the model emphasise the importance of the stomatal and soil compensation point, which govern the pollutant flux.
- Publication:
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EGS - AGU - EUG Joint Assembly
- Pub Date:
- April 2003
- Bibcode:
- 2003EAEJA.....2755P