Measurements of the surface layer turbulence in the urban area

Abstract

The turbulence characteristics measured in the surface layer over a real underlying surface are presented. The measurements are carried out at the 3-and 16-m levels using acoustic anemometers; at the lower level, the measurements are doubled. The diurnal cycle is obtained of the temperature flux and friction velocity. To obtain the temperature flux, so-called "acoustic" temperature is used as calculated from the sound speed data with corrections for air humidity and pressure. The normalized characteristics of turbulence are presented as dependent on dimensionless height z/L. The values of temperature flux and friction velocity increase with height: their day-integral values at 16-m level exceed those at 3-m level for about 20 and 35%, respectively.

Turbulence characteristics in the coastal zone with breeze circulation

“…The measurements of wind speed parameters up to the height of 1000 m were carried out using the MFAS ultrasonic radar (sodar) of Scintec production [1]. The latter is installed on the roof of the main office building of the testing area; its initial (lower) measurement level above the Earth's surface is 40 m. For measuring the meteorological variables and turbulence characteristics in the surface layer, an MK-15 automatic complex [2] was used developed and produced at the Research and Production Association Taifun (Obninsk, Russia). The three-component ultrasonic anemometer and other sensors of MK-15 complex are placed on the meteorolo-gical site located at the distance of about 500 m from the shore at the height of about 30 m above sea level.…”