Effects of Clouds, Soil Moisture, Precipitation, and Water Vapor on Diurnal Temperature Range

Abstract

The diurnal range of surface air temperature (DTR) has decreased worldwide during the last 4-5 decades and changes in cloud cover are often cited as one of the likely causes. To determine how clouds and moisture affect DTR physically on daily bases, the authors analyze the 30-min averaged data of surface meteorological variables and energy fluxes from the the First International Satellite Land Surface Climatology Project Field Experiment and the synoptic weather reports of 1980-1991 from about 6500 stations worldwide. The statistical relationships are also examined more thoroughly in the historical monthly records of DTR, cloud cover, precipitation, and streamflow of this century.