THE SPATIAL AND TEMPORAL VARIABILITY OF THE WIND SPEED WITHIN THE URBAN BOUNDARY LAYER

The mesoscale wind velocity variance at two sites within the Moscow megalopolis was studied.. Two identical sodars – one in the center of the city, the other in the south-west district 7 km apart from the center synchronously have been operating during 3 years. The sites differ in altitude a.s.l., landscape and urban building density. Comparison of mean wind speed profiles made between the sites for different time of day and seasons has shown a rather good agreement provided all the data were given to the altitude of the same mean velocity. Comparison of variance distributions also confirms the need to bring the data to the appropriate altitude. Concurrent in situ measurements of wind speed variability with ultrasonic anemometer are carried out at one of the sites since May 2007. Relation between the values of the turbulent kinetic energy (TKE) and variance of the vertical wind component obtained by in situ measurements were compared with sodar ones. Variability of w2 is compared with other characteristics variability