Seasonal dynamics in methane emissions from the Amazon River floodplain to the troposphere

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

DOI:https://doi.org/10.1029/JD095iD10p16417· OSTI ID:6100361

Devol, A H; Richey, J E ^[1]; Forsberg, B R ^[2]; Martinelli, L A ^[3]

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1. Univ. of Washington, Seattle (USA)
2. Instituto Nacional de Pesquisas da Amazonia, Manaus (Brazil)
3. Centro de Energia Nuclear na Agricultura, Piracicaba (Brazil)

Methane fluxes to the troposphere from the three principal habitats of the floodplain of the Amazon River main stem (open waters, emergent macrophyte beds, and flooded forests) were determined along a 1,700-km reach of the river during the low-water period of the annual flood cycle (November-December 1988). Overall, emissions averaged 68 ({plus minus} 20) mg CH{sub 4} m{sup {minus}2} d{sup {minus}1} and were significantly lower than similar emissions determined previously for the high-water period, 184 ({plus minus} 41) mg CH{sub 4} m{sup {minus}2} d{sup {minus}1} (July-August 1986). This difference was due to significantly lower emissions from floating macrophyte environments. Low-water emissions from open waters and flooded forest areas were not significantly different than at high water. A monthly time series of methane emissions from eight lakes located in the central Amazon basin showed similar results. Average annual emission from the lakes was 125 ({plus minus} 28) mg CH{sub 4} m{sup {minus}2} d{sup {minus}1}. Methane emissions from lakes were significantly higher during the high water period, again primarily due to an increase in emissions from macrophyte habitats. The data were used to calculate a seasonally weighted annual emission to the troposphere from the Amazon River main stem floodplain of 5.1 Tg yr{sup {minus}1}, which indicates the importance of the area in global atmospheric chemistry.

• OSTI ID: 6100361
• Journal Information: Journal of Geophysical Research; (USA), Vol. 95:D10; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
METHANE
ENVIRONMENTAL TRANSPORT
SURFACE WATERS
DEGASSING
TROPOSPHERE
ATMOSPHERIC CHEMISTRY
AMAZON RIVER
BRAZIL
ECOLOGICAL CONCENTRATION
EMISSION
FLOODS
FORESTS
GLOBAL ASPECTS
SEASONAL VARIATIONS
ALKANES
CHEMISTRY
DEVELOPING COUNTRIES
DISASTERS
EARTH ATMOSPHERE
HYDROCARBONS
LATIN AMERICA
MASS TRANSFER
ORGANIC COMPOUNDS
RIVERS
SOUTH AMERICA
STREAMS
VARIATIONS
540120* - Environment
Atmospheric- Chemicals Monitoring & Transport- (1990-)
540320 - Environment
Aquatic- Chemicals Monitoring & Transport- (1990-)