Emission of nitric oxide (NO) from tropical forest soils and exchange of NO between the forest canopy and atmospheric boundary layers
- Harvard Univ., Cambridge, MA (USA)
- Princeton Univ., NJ (USA)
- Lamont-Doherty Geophysical Observatory, Palisades, NY (USA)
Emissions of NO from soils in the Amazon rain forest were measured at 66 locations (224 measurements) using an enclosure technique, and continuous vertical profiles of NO and O{sub 3} were measured between the ground and 41-m altitude. Fluxes of NO averaged 8.9 ({plus minus}1.5) {times} 10{sup 9} molecules cm{sup {minus}2} s{sup {minus}1} from the dominant (yellow clay) soils of the region, with larger fluxes (33.7 ({plus minus}6.5) {times} 10{sup 9} molecules cm{sup {minus}2} s{sup {minus}1}) observed from adjacent white sand soils. Fluxes from clay soils were lower by more than a factor of 5 than fluxes observed during the dry season at a nearby site. Low soil emission rates were reflected in lower concentrations of NO at the top of the forest canopy in the west season, only 30-50 pptv (parts per trillion by volume) during the daytime. The measured fluxes are consistent with chemical mass balances for NO within the forest canopy, calculated from the NO and O{sub 3} profiles taken at night, and with observations of NO between 150 and 5,000 m altitude. Measurements of NO emission rates from soil plots fertilized using NaNO{sub 3}, NH{sub 4}Cl or sucrose indicated that a reductive pathway (denitrification) may have been primarily responsible for production of the NO released by both clay and sand soils.
- OSTI ID:
- 6100421
- Journal Information:
- Journal of Geophysical Research; (USA), Journal Name: Journal of Geophysical Research; (USA) Vol. 95:D10; ISSN 0148-0227; ISSN JGREA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
540120* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
540220 -- Environment
Terrestrial-- Chemicals Monitoring & Transport-- (1990-)
AIR POLLUTION
ALTITUDE
AMAZON RIVER
BOUNDARY LAYERS
BRAZIL
CANOPIES
CHALCOGENIDES
CHEMICAL REACTIONS
CLAYS
DAILY VARIATIONS
DEGASSING
DENITRIFICATION
DEVELOPING COUNTRIES
EARTH ATMOSPHERE
ECOLOGICAL CONCENTRATION
EMISSION
ENVIRONMENTAL TRANSPORT
FERTILIZERS
FORESTS
LATIN AMERICA
LAYERS
MASS BALANCE
MASS TRANSFER
NITRIC OXIDE
NITROGEN COMPOUNDS
NITROGEN OXIDES
OXIDES
OXYGEN COMPOUNDS
OZONE
POLLUTION
RIVERS
SAND
SEASONAL VARIATIONS
SOILS
SOUTH AMERICA
STREAMS
SURFACE WATERS
VARIATIONS