Vertical and Horizontal Wind Variations in Troposphere and Lower Stratosphere

Abstract

The results of analysis of a sample data tape obtained from Poker Flat (Alaska) MST radar covering 4-day period from 31 Jan. to 3 Feb. 1982 for studying the spatial and temporal variations of vertical and horizontal wind in troposphere and lower stratosphere are presented. The three radial velocities, measured by the two 'oblique' and one 'vertical' beams, as recorded on the tape, were converted to zonal (<i>U</i>), meridional (<i>V</i>) and vertical (<i>W</i>) components. These components of velocities were then averaged over 1-hr interval and their temporal and spatial variations studied. It was-found that the time series of vertical velocity with time resolution of about 2 min showed evidence of periodic, though less regular, oscillations with amplitudes of 0.5-1.0 m s^-1. The diurnal plot of 1-hr averaged vertical velocity showed a value very close to zero. The zonal velocity averaged over 1-hr period generally showed an eastward trend with magnitude of variation in the range 5-20 m s^-1at heights of 12.5, 14.7 and 16.9 km with more variability at 10.3 km. The meridional velocity generally remained southward at higher heights with magnitude of fluctuations varying between 1 and 10 m s^-1 and again with more variability at 10.3 km altitude. This variability of zonal and meridional velocities suggests that the lower regions are more unstable than the higher regions.