Additionally, land surface temperatures have a marked diurnal cycle. Based on experiences from evaluating sea surface temperature algorithms, a practical multiband LST hierarchical algorithm will be developed that will incorporate regional and seasonal characteristics, viewing angle and topographic effects, and land cover grouping according to spectral emissivity and reflectivity features. Fire Product Fire played a critical role in the development of existing patterns of global vegetation and continues to be an important process in several major biomes. In the boreal forest regions it is a primary agent in forest succession. In the tropics, fire plays an integral role in savanna ecosystem functioning and nutrient cycling, and is used extensively for agriculture.
Fire is also a major source of trace gases and particulates in the atmosphere.
Current estimates of trace gas emissions from biomass burning are severely constrained by the lack of reliable statistics on fire distribution and frequency, accurate estimates of area burned, fuel load, and fuel moisture content. Currently, no single remote sensing system provides the data needed for an effective global fire monitoring program. Estimates will be made of the total emitted energy from the fire and the ratio of smoldering to flaming components. Biophysical Variables A number of biophysical parameters are also required for use in advanced global models of climate, hydrology, biogeochemistry and ecology. These variables describe vegetation canopy structure, and are related to functional process rates of energy and mass exchange.