Dynamics of the Kinetic Energy in the Atmospheric Boundary Layer from the Results of Minisodar Measurements

Abstract

Based on acoustic remote measurements of vertical profiles of three wind velocity components in a 200-meter boundary layer of the atmosphere, values of the kinetic energy of the atmosphere and its components: kinetic energy of ordered motion E_MKE (with average wind velocity) and turbulent kinetic energy E_TKE are estimated. An analysis of their vertical profiles has demonstrated that at altitudes up to ~25–50 m, the turbulent kinetic energy values and their spreads are very small and sharply increase with altitude. The maximum E_TKE values are observed at midnight, as well as the maximum E_MKE values. In the morning, the contribution of the kinetic energy of the ordered motion in the lower 100-meter layer of the atmosphere exceeds that of the turbulent motion, which can be caused by the presence of a wind shear in the corresponding wind velocity profiles. The vertical E_MKE profile increases in the morning, reaches maximum values by noon, and then decreases by midnight. The diurnal variations of the kinetic energy are characterized by the presence of several minima and maxima whose values and times of occurrence depend on the meteorological conditions during sounding session, the presence and characteristics of cloudiness, and the solar radiation intensity.