Approach:

Monthly NASA-CASA model estimates of NO emissions from soils were simulated for a nine-state region of the southeastern USA, as part of the Southern Oxidants Study (SOS). Simulations used a regional geographic information system (GIS) as the data source for climate drivers, satellite images, land cover, and soil properties over a 8-km grid resolution. The simulated emissions were used to place the relative magnitude of soil NO emissions into perspective with other regional sources of NOx, and to examine spatial and temporal patterns of soil NO emissions across the region.

Major findings:

• Fertilized soil sources of NO predicted by the model were large enough to have an adverse impact on local air quality in rural areas.
• Model estimates of NO emission rates from farmed and forest soils were consistent with measured emission rates.

References:

Davidson, E. A., C. S. Potter, S. A. Klooster, and P. Schlesinger. 1998. Model estimates of regional nitric oxide emissions from soils of the southeastern United States. Ecological Applications. 8:748-759.

Soil NO emission estimated at 8-km cell resolution by the NASA-CASA model for the nine-state SOS region of the southeastern USA.

Soil NO emission

Produced in collaboration with E. Davidson (Woods Hole Research Center), with grant support from the Southern Oxidants Study.