SURFATM-NH3: a model combining the surface energy balance and bi-directional exchanges of ammonia applied at the field scale 1UMR Environment et Grandes Cultures/INRA – AgroParisTech, 78850 Thiverval Grignon, France
2Agroscope Reckenholz-Tänikon Research Station ART, Reckenholzstrasse 191, 8046 Zürich, Switzerland
3Plant and Soil Science Laboratory, University of Copenhagen, Faculty of Life Sciences, Thorvaldsensvej 40, 1871 Frederiksberg C, Copenhagen, Denmark
4Centre for Ecology and Hydrology, Edinburgh Research Station, Bush Estate, Penicuik, Midlothian, EH26 0QB, UK
Received: 30 Sep 2008 – Published in Biogeosciences Discuss.: 06 Jan 2009 – Published: 04 Aug 2009Abstract. A new biophysical model SURFATM-NH3, simulating the ammonia (NH3)
exchange between terrestrial ecosystems and the atmosphere is presented.
SURFATM-NH3 consists of two coupled models: (i) an energy budget model and
(ii) a pollutant exchange model, which distinguish the soil and plant
exchange processes. The model describes the exchanges in terms of adsorption
to leaf cuticles and bi-directional transport through leaf stomata and soil.
The results of the model are compared with the flux measurements over
grassland during the GRAMINAE Integrated Experiment at Braunschweig,
Germany. The dataset of GRAMINAE allows the model to be tested in various
meteorological and agronomic conditions: prior to cutting, after cutting and
then after the application of mineral fertilizer. The whole comparison shows
close agreement between model and measurements for energy budget and ammonia
fluxes. The major controls on the ground and plant emission potential are
the physicochemical parameters for liquid-gas exchanges which are integrated
in the compensation points for live leaves, litter and the soil surface.
Modelled fluxes are highly sensitive to soil and plant surface temperatures,
highlighting the importance of accurate estimates of these terms. The model
suggests that the net flux depends not only on the foliar (stomatal)
compensation point but also that of leaf litter. SURFATM-NH3 represents a
comprehensive approach to studying pollutant exchanges and its link with
plant and soil functioning. It also provides a simplified generalised
approach (SVAT model) applicable for atmospheric transport models.
Citation: Personne, E., Loubet, B., Herrmann, B., Mattsson, M., Schjoerring, J. K., Nemitz, E., Sutton, M. A., and Cellier, P.: SURFATM-NH3: a model combining the surface energy balance and bi-directional exchanges of ammonia applied at the field scale, Biogeosciences, 6, 1371-1388, doi:10.5194/bg-6-1371-2009, 2009.