Delineation of Cold-Prone Areas Using Nighttime SMS/GOES Thermal Data: Effects of Soils and Water

Abstract

Infrared digital data from geostationary satellites were used to demonstrate the usefulness of remotely sensed surface temperature data to delineate microscale and mesoscale climates. Nocturnal winter data (December-February) from 1976–77 to 1978–79 over Florida revealed noticeable contrasts in surface temperature patterns. Colder areas were associated with low soil moisture content in the upper layers of excessively-drained and well-drained sandy soils, whereas warmer areas were associated with bodies of water, wetlands, or poorly drained soils. An unexpected surface temperature pattern for one night where the north-central Florida climatic zone was colder than the north Florida climatic zone was found to be caused by differences in antecedent frontal rainfall. Differences in surface radiant energy fluxes over these two areas at 0200 EST 20 December 1977, based on average satellite-sensed surface temperatures, were compared with differences in soil heat fluxes that were computed from 1.5 m climatological temperatures and soil thermal properties by use of a simplified surface energy balance equation. The difference in computed soil heat fluxes was in reasonable agreement with the difference in radiant energy fluxes from the surface of the two areas. It was therefore concluded that this method could be used to compute differences in thermal inertia of the surface layer of different areas based on satellite and climatological temperature data.