PARENT SESSION
Poster Session 14: GIS and Remote Sensing
Tuesday, August 9, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal
Developing a disturbance index and extreme land surface temperature in the western United States.
Mildrexler, David*,1, Zhao, Maosheng*,1, Running, Steve*,1, 1 University of Montana, Missoula
ABSTRACT- Land surface temperature (LST) is one of the key parameters in the physics of land surface processes, combining surface-atmosphere interactions and the energy fluxes between the atmosphere and the ground. Increases in LST could produce profound changes in the forests at high and temperate latitudes, and result in increased carbon dioxide emissions from terrestrial disturbance events such as drought and wildfire. The timing, location and magnitude of major disturbance events is currently a major uncertainty in the global carbon cycle. The Aqua sensor, aboard the Terra Spacecraft, was launched in 2002 and has yet to be tested for its full capacity as a land surface remote sensor. The MODIS/Aqua 11 LST product provides global estimates of radiometric LST with continuous spatial coverage. We analyze the sensitivity of the LST estimates at the fine scale by comparing the maximum LST of a poplar tree plantation in the desert of eastern Oregon to the adjacent natural land cover types. At the coarse scale, a strong negative correlation was observed between the mean-maximum LST and the mean-maximum enhanced vegetation index (EVI) over all biomes in the western United States. Based on this relationship we develop a disturbance index using LST and the EVI. Our results indicate that the LST/EVI interannual disturbance index is capable of detecting relatively large disturbances with good accuracy, such as wildfire, and the impacts of interannual weather variability on vegetation. LST maps highlighting physiologically defined potentially lethal LST were created and compared to biome distribution. The extreme temperature maps provide a fresh look into the spatial distribution and interannual variability of these temperatures.
Key words: land surface temperature, extreme temperature, disturbance monitoring