Low-Level Jets in the Moscow Region in Summer and Winter Observed with a Sodar Network |
| |
Authors: | Margarita A Kallistratova Rostislav D Kouznetsov |
| |
Institution: | 1.A.M. Obukhov Institute of Atmospheric Physics,Moscow,Russia;2.Finnish Meteorological Institute,Helsinki,Finland |
| |
Abstract: | We evaluate the statistical properties of low-level jets (LLJs) observed by means of a network of Doppler sodars in the Moscow
region, Russia. Continuous long-term measurements of the echo-signal intensity and wind-velocity profiles were carried out
in July 2005 and in 2008–2010 synchronously in the centre of Moscow and at a rural site. The summertime nocturnal LLJs have
a very clear diurnal cycle and exhibit features predicted by the Blackadar mechanism. In contrast, the long-lasting wintertime
jets do not have any clear diurnal variability. The urban environment strongly influences LLJs in both seasons: above the
city LLJs are higher, weaker and observed more rarely than at the rural site. In very cold periods (air temperature below
−8°C) no LLJs were observed over the city, instead convection emerged in the urban boundary layer. The results are based on
observations made in July 2005, January and December 2009, and January 2011. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|