Relations between Surface Temperature and Air Temperature on a Local Scale during Winter Nights

Abstract

The relations between surface temperature and air temperature on clear winter nights were investigated with regard to spatial scale and the vegetation effect at a local meteorological scale. The study was based on nighttime images obtained from the Landsat Thematic Mapper and high-density meteorological data obtained from the Automated Meteorological Data Acquisition System (AMeDAS). The correlation coefficients between the air temperatures and the surface temperatures at the AMeDAS stations were relatively high despite the simple comparison. Surface temperature alone explained 80% of the observed variation in air temperature. The spatial scales of the effect of surface temperature on air temperature and the effect of vegetation density on air temperature were related to the mean lapse rate of the atmospheric boundary layer. Air temperature was more sensitive to vegetation density when the mean lapse rate of the atmospheric boundary layer was smaller. Accuracy in the estimation of air temperature from satellite-derived surface temperature data was improved by multiple regression using the spatially averaged surface temperature and normalized difference vegetation index.