Submitted to: American Geophysical Union
Publication Type: Abstract Only
Publication Acceptance Date: September 5, 2000
Publication Date: November 28, 2000
Interpretive Summary: With the launch of NASA's Terra satellite in December 1999 a new tool for studying the earth's surface has become available multispectral thermal infrared. These data can be used for the emissivity of the land surface on a global basis. The emissivity of the surface has a major effect on the radiation energy balance at the earth's surface. Therefore, knowledge of the spatial variation of the surface emissivity is important for quantifying the radiation balance at the earth's surface. This paper presents preliminary results of a technique for observing this spatial variation. While these results were obtained using data from an aircraft sensor, it is extendable to data from satellite platforms and thus could be used on a global basis.
In June and September 2000, the Advanced Spaceborne Thermal Emission and Reflection radiometer (ASTER) on the Terra satellite obtained data over several test sites along the Rio Grande river in New Mexico. ASTER has 14 channels from the VNIR through the TIR with 15 m resolution in VNIR and 90 m in the thermal. The multispectral TIR data from ASTER provides the opportunity to separate the temperature and emissivity effects observed in the thermal emission from the land surface. The sites include the Sevilleta and Bosque del Apache National Wildlife Refuges, the Elephant Butte reservoir and the Jornada Experimental Range. Ground measurements during these overflights included surface temperature, vegetation type and condition and surface flux measurements. There was also an aircraft flight with the MODIS/ASTER simulator on June 14, 2000, unfortunately not coincident with a satellite overpass. Preliminary results indicate good agreement between ASTER brightness temperatures and ground measures at the reservoir. Analysis of earlier aircraft data have show that the multispectral TIR data are very effective for estimating both the surface temperature and emissivity. These results will be compared with the ASTER data.