Standard deviation of the wind vertical component and its dynamics in Moscow by the sodar data

Abstract

For the first time long-term data on standard deviation of the vertical wind component in the lower 250 m air layer in Moscow are presented. They have been received by results of continuous sodar measurements during six last years. The climatologic features of its diurnal and annual course for various seasons have been discussed. In average this parameter varies usually from 0.6 to 0.8 m/s, in the afternoon in summer - up to 1 m/s. The diurnal course is flat in winter and has a clear daily maximum in the other seasons connected with the thermal convection. The annual course is characterized by a maximum in June and the lowest values in autumn and in winter. Clear asymmetry between the transitional seasons (spring and autumn) are detected. The values of this parameter are clearly depending on the synoptic conditions. They are highest in the rear of cyclones after the passing of the cold front and in cold air masses due to the intense development of thermal convection there.