Airborne Ground Penetrating Radar (GPR) for peat analyses in the Canadian Northern wetlands study

The study was conducted as part of the NASA Biospherics Research on Emissions from Wetlands (BREW) program. An important aspect of the program is to investigate the terrestrial production and atmospheric distribution of methane and other gases contributing to global warming. Multi-kilometer transects of airborne (helicopter) Ground Penetrating Radar (GPR) data were collected periodically along the 100 km distance from the coast inland so as to obtain a regional trend in peat depth and related parameters. Global Positioning System (GPS) data were simultaneously collected from the helicopter to properly georeference the GPR data. Additional 50 m ground-based transects of GPR data were also collected as a source of ground truthing, as a calibration aid for the airborne data sets, and as a source of higher resolution data for characterizing the strata within the peat. In situ peat depth probing and soil characterizations from excavated soil pits were used to verify GPR findings. Results from the ground-based data are presented

Emissions of sulfur gases from marine and freshwater wetlands of the Florida Everglades: Rates and extrapolation using remote sensing

Rates of emissions of the biogenic sulfur (S) gases carbonyl sulfide (COS), methyl mercaptan (MSH), dimethyl sulfide (DMS), and carbon disulfide (CS2) were measured in a variety of marine and freshwater wetland habitats in the Florida Everglades during a short duration period in October using dynamic chambers, cryotrapping techniques, and gas chromatography. The most rapid emissions of greater than 500 nmol/m(sup -2)h(sup -1) occurred in red mangrove-dominated sites that were adjacent to open seawater and contained numerous crab burrows. Poorly drained red mangrove sites exhibited lower fluxes of approximately 60 nmol/m(sup -2)h(sup -1) which were similar to fluxes from the black mangrove areas which dominated the marine-influenced wetland sites in the Everglades. DMS was the dominant organo-S gas emitted especially in the freshwater areas. Spectral data from a scene from the Landsat thematic mapper were used to map habitats in the Everglades. Six vegetation categories were delineated using geographical information system software and S gas emission were extrapolated for the entire Everglades National Park. The black mangrove-dominated areas accounted for the largest portion of S gas emissions to the area. The large area extent of the saw grass communities (42 percent) accounted for approximately 24 percent of the total S emissions