Role of the Hudson Bay Lowland as a source of atmospheric methane
- York Univ., Ontario (Canada)
- Ontario Centre for Remote Sensing, Ontario (Canada)
- Univ. of Manitoba, Winnipeg (Canada)
- National Center for Atmospheric Research, Boulder, CO (United States)
- McGill Univ., Quebec (Canada)
- Guelph Univ., Quebec (Canada)
- NASA Langley Research Center, Hampton, VA (United States)
- McMaster Univ., Hamilton (Canada)
Based on point measurements of methane flux from wetlands in the boreal and subarctic regions, northern wetlands are a major source of atmospheric methane. However, measurements have not been carried out in large continuous peatlands such as the Hudson Bay Lowland (HBL) (320,000 km{sup 2}) and the Western Siberian lowland (540,000 km{sup 2}), which together account for over 30% of the wetlands north of 40{degrees}N. To determine the role the Hudson Bay Lowland as a source of atmospheric methane, fluxes were measured by enclosure throughout the 1990 snow-free period in all the major wetland types and also by an aircraft in July. Two detailed survey areas were investigated: one ({approx} 900 km{sup 2}) was in the high subarctic region of the northern lowland and the second area ({approx} 4,800 km{sup 2}) straddled the Low Subarctic and High Boreal regions of the southern lowland. On a per unit area basis, 1.31 {+-} 0.11 and 2.79 {+-} 0.39 g CH{sub 4} m{sup {minus}2} yr{sup {minus}1} were emitted from the southern and northern survey areas, respectively. The extrapolated enclosure estimates for a 3-week period in July were compared to within 10% of the flux derived by airborne eddy correlation measurements made during the same period. The aircraft mean flux of 10 {+-} 9 mg CH{sub 4} m{sup {minus}2} d{sup {minus}1} was not statistically different from the extrapolated mean flux of 20 {+-} 16 mg CH{sub 4} m{sup {minus}2} d{sup {minus}1}. The annual habitat-weighted emission for the entire HBL using six wetland classes is estimated as 0.538 {+-} 0.187 Tg CH{sub 4} yr{sup {minus}1} (range of extreme cases is 0.057 to 2.112 Tg CH{sub 4} yr{sup {minus}1}). This value is much lower than expected, based on previous emission estimates from northern wetlands. 40 refs., 6 figs., 8 tabs.
- OSTI ID:
- 81543
- Journal Information:
- Journal of Geophysical Research, Vol. 99, Issue D1; Other Information: PBD: 20 Jan 1994
- Country of Publication:
- United States
- Language:
- English
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