HR: 1340h
AN: A23C-1466    [Abstracts]
TI: Applications of Satellite Remote Sensing Data for Biogenic Emission Estimates in Southeastern Texas
AU: * Feldman, M S
EM: feldman@che.utexas.edu
AF: Center for Energy and Environmental Resources University of Texas at Austin, 10100 Burnet Road, Bldg. 133, R7100, Austin, TX 78758,
AU: Howard, T
AF: Center for Space Research University of Texas at Austin, 3925 West Braker Lane, Suite 200, Austin, Tx 78759,
AU: Mullins, G
AF: Center for Space Research University of Texas at Austin, 3925 West Braker Lane, Suite 200, Austin, Tx 78759,
AU: McDonald-Buller, E
EM: ecmb@mail.utexas.edu
AF: Center for Energy and Environmental Resources University of Texas at Austin, 10100 Burnet Road, Bldg. 133, R7100, Austin, TX 78758,
AU: Allen, D T
EM: allen@che.utexas.edu
AF: Center for Energy and Environmental Resources University of Texas at Austin, 10100 Burnet Road, Bldg. 133, R7100, Austin, TX 78758,
AB: Biogenic hydrocarbons, including isoprene, monoterpenes, and oxygenated compounds, are emitted in substantial quantities by vegetation and dominate the overall volatile organic compound emission inventory in Southeastern Texas. Spatial distributions of biogenic emissions in Texas are heterogeneous, and biogenic emission processes are affected by the characterization of land cover, leaf area index, drought stress, and surface temperatures. On a regional scale, biogenic emissions, particularly isoprene, in the presence of high levels of nitrogen oxides (NOx), will produce elevated ground-level ozone concentrations. The sensitivity of biogenic emission estimates and air quality model predictions to the characterization of land use/land cover (LULC) in southeastern Texas is examined. A LULC database has been developed for the region based on source imagery collected by the Landsat 7 Enhanced Thematic Mapper-Plus sensor between 1999 and 2003, and data from field studies used for species identification and quantification of biomass densities. This database and the LULC database currently used in regulatory air quality models by the State of Texas are compared. Effects of the LULC data on biogenic emission estimates and modeled ozone concentrations are examined using the Global Biosphere Emissions and Interactions System and the Comprehensive Air Quality Model with extensions during an August 22-September 6, 2000 episode developed for the Houston/Galveston area. These results are also compared to biogenic emission estimates from the recently created Model of Emissions of Gases and Aerosols from Nature (MEGAN), which includes a global vegetation map compiled from recent satellite data and ecosystem inventories. Biogenic emissions estimated from the new LULC dataset showed good general spatial agreement with those from the currently used LULC dataset but significantly lower emissions (~40% less hourly emissions across the modeling domain), primarily due to differences in biomass density of key species like Quercus (Oak). Predicted ozone concentrations using the biogenic emissions produced from the new LULC dataset are as much as 25 ppb lower in some areas on some days, depending on meteorological conditions. Along with coordinated data collection during the Texas Air Quality Study II (TexAQS II), this study demonstrates how satellite remote sensing data can be applied in air quality models and assessments to provide new insights on the magnitude and spatial distribution of biogenic hydrocarbons. Satellite data and image classification techniques provide useful tools for mapping and monitoring changes in LULC. However, field validation is necessary to link species and biomass densities to the classification system used for accurate biogenic emissions estimates, especially in areas such as riparian corridors that contain concentrations of key species.
DE: 0315 Biosphere/atmosphere interactions (0426, 1610)
DE: 0322 Constituent sources and sinks
DE: 0480 Remote sensing
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting