Dewpoint Temperature Inversions

Abstract

A study was made of the diurnal and seasonal variations of the vertical dewpoint gradient based on measurements taken at 1.2, 9.4 and 131 ft above ground at the Argonne National Laboratory during the period 1 December 1960 through 30 November 1965. The results of this study are used to assess the effects of the dewpoint temperature inversion on vegetative growth, dew formation and corrosion. Case studies employing time series presentations are used to relate the magnitude and direction of the dewpoint gradient with other meteorological variables such as air and soil temperature, pressure, solar radiation, net radiation flux, wind speed and direction, relative humidity and stability. These analyses illustrate the processes operating to influence the magnitude and direction of moisture flux in the lower atmospheric layers. Joint frequency distributions are presented relating the vertical dewpoint temperature gradient with each of the variables—air temperature between 144 and 5.5 feet, relative humidity, net radiation flux and wind speed. Also, a multivariate study is presented showing the relations among the occurrence frequency of dewpoint inversion, wind speed, relative humidity and net radiation flux. From this study, it is possible to determine the relation between the occurrence frequency of the dewpoint inversion and any one of the above variables with the other two held constant. A similar study is presented with the air temperature difference between 144 and 5.5 ft replacing net radiation flux as one of the variables.