Empirical model of global soil-biogenic NO{sub x} emissions
- Princeton Univ., NJ (United States)
The authors construct a global, temperature and precipitation dependent, empirical model of soil-biogenic NO{sub x} emissions using 6-hour general circulation model forcing. New features of this source relative to the latest published ones by Dignon et al. and Muller include synoptic-scale modeling of {open_quotes}pulsing{close_quotes} (the emissions burst following the wetting of a dry soil), a biome dependent scheme to estimate canopy recapture of NO{sub x}, and an explicit linear dependence of emission on N fertilizer rate for agricultural soils. Their best estimate for annual above-canopy emissions is 5.5 Tg N (NO{sub x}) with a range of 3.3-7.7 Tg N. Globally, the strongest emitters are agriculture, grasslands, and tropical rain forests, accounting for 41%, 35%, and 16% of the annual budget, respectively. {open_quotes}Pulsing{close_quotes} contributes 1.3 Tg N annually. In temperate regions, agriculture dominates emission, and in tropical regions, grassland dominates. Canopy recapture is significant, consuming, on average, possibly 50% of soil emissions. In temperate regions, periodic temperature changes associated with synoptic-scale disturbances can cause emission fluctuations of up to 20 ng N m{sup {minus}2}s{sup {minus}1}, indicating a close correlation between emission and warm weather events favorable to O{sub 3}/smog formation. By the year 2025, increasing use of nitrogen fertilizer may raise total annual emissions to 6.9 Tg N with agriculture accounting for more than 50% of the global source. Finally, biomass burning may add up to an additional 0.6 Tg N globally by stimulating emissions for a short period after the burn. 74 refs., 4 figs., 9 tabs.
- OSTI ID:
- 136174
- Journal Information:
- Journal of Geophysical Research, Journal Name: Journal of Geophysical Research Journal Issue: D6 Vol. 100; ISSN JGREA2; ISSN 0148-0227
- Country of Publication:
- United States
- Language:
- English
Similar Records
Hourly and daily rainfall intensification causes opposing effects on C and N emissions, storage, and leaching in dry and wet grasslands
Nitrogen oxide emissions from soils following clearing of secondary tropical forest