Using remotely sensed data to monitor land surface climatology variations in a semi-arid grassland

Long-term overgrazing in Mexico has caused a sharp discontinuity in surface properties along the international border in the semiarid Sonoran Desert. The United States side, protected from overgrazing by the Taylor Act since 1934, exhibits longer, more plentiful grasses, less bare soil, and lower albedo than adjoining Mexican lands. The difference in surface properties affects evapotranspiration rates and evokes a temperature gradient between the two countries. The more exposed Mexican landscape tends to dry more rapidly than the United States following summer convective precipitation. Depletion of soil moisture causes higher surface and air temperatures in Mexico. Several satellite datasets, along with supporting ground and aircraft data, were used to detect and monitor differences between the two semiarid grassland regimes.