Ozone and aerosol distributions over the Amazon basin during the wet season

Journal Article · Thu Sep 20 04:00:00 EDT 1990 · Journal of Geophysical Research; (USA)

DOI:https://doi.org/10.1029/JD095iD10p16887· OSTI ID:6100983

Browell, E V; Gregory, G L ^[1]; Harriss, R C ^[2]; Kirchhoff, V W.J.H. ^[3]

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1. NASA Langley Research Center, Hampton, VA (USA)
2. Univ. of New Hampshire, Durham (USA)
3. Instituto de Pesquisas Espaciais, Sao Paulo (Brazil)

Measurements of ozone (O{sub 3}) and aerosols were made over the tropical rain forest of Brazil during the wet season in April-May 1987 as part of the NASA Global Tropospheric Experiment to study the Amazon boundary layer. Remote and in situ measurements of O{sub 3} and aerosols were made from aircraft on flights over Brazil in the vicinity of Manaus and between Manaus and Belem. Ozonesonde data were also obtained near Manaus. Ozone mixing ratios of <12 ppbv were found in the mixed layer during the wet season with no significant evidence of O{sub 3} produced from biomass burning or photochemistry. These values are lower than those found during the 1985 dry season by 6-8 ppbv. These low O{sub 3} mixing ratios indicate a strong removal process near the surface during the wet season. The region from the mixed layer top to 3 km in altitude had a slowly increasing O{sub 3} profile from 12 to 20 ppbv. On long-range flights between Manaus and Belem, no significant difference was found in the distribution of O{sub 3} above the mixed layer between the inland tropical rain forest and the marine conditions near the coast. Within the mixed layer, there was a definite trend to lower O{sub 3} levels above the forest compared to over the ocean. This reflects the marked difference in the sinks for O{sub 3} over these two regions. The rate of growth of the mixed layer over the rain forest in the wet season was found to be {approximately}9 cm s{sup {minus}1}, which is within the 7-10 cm s{sup {minus}1} range found for the dry season. There was no evidence of the trade wind inversion that was seen during the dry season, and due to frequent precipitation, the background aerosol loading was lower in the wet season than in the dry season.

• OSTI ID: 6100983
• Journal Information: Journal of Geophysical Research; (USA), Journal Name: Journal of Geophysical Research; (USA) Vol. 95:D10; ISSN JGREA; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540120* -- Environment
Atmospheric-- Chemicals Monitoring &amp; Transport-- (1990-)
AEROSOLS
AIR POLLUTION MONITORING
AIR-BIOSPHERE INTERACTIONS
AIRCRAFT
ALTITUDE
AMAZON RIVER
ATMOSPHERIC CHEMISTRY
ATMOSPHERIC PRECIPITATIONS
BIOMASS
BOUNDARY LAYERS
BRAZIL
CHEMICAL REACTIONS
CHEMISTRY
COASTAL REGIONS
COLLOIDS
COMBUSTION
COMPARATIVE EVALUATIONS
DEVELOPING COUNTRIES
DISPERSIONS
DISTRIBUTION
EARTH ATMOSPHERE
ECOLOGICAL CONCENTRATION
ENERGY SOURCES
FORESTS
LATIN AMERICA
LAYERS
MIXING
OXIDATION
OZONE
PHOTOCHEMISTRY
REMOTE SENSING
RENEWABLE ENERGY SOURCES
RIVERS
SEAS
SEASONAL VARIATIONS
SINKS
SOLS
SOUTH AMERICA
STREAMS
SURFACE WATERS
THERMOCHEMICAL PROCESSES
TROPOSPHERE
VARIATIONS