Vol. 22, issue 03, article # 7

Abstract:

The results of measurements of the carbon monoxide total content are given for the period 1993-2007 using the absorption of solar radiation in the atmospheric column over Moscow. This method makes it possible to separate an urban part of the CO content by virtue of a comparison of the CO content measured at two observation sites, one of which being situated in the rural zone and the other one being situated in the city center. Two identical grating spectrometers of medium resolution (0.2 cm-1) are used with appropriate solar tracking systems. Starting from 2005 the permanent sounding of boundary layer has been carried out using acoustic locator (SODAR) LATAN-3 intended to determine the boundary layer parameters. Variations in the CO content depend mainly on the variations of the wind-velocity or temperature inversions. Correlation coefficients were obtained for the urban part of the CO content with the average wind speed for cold and warm seasons. The use of SODAR data demonstrates preeminent influence of the wind in certain boundary layer (up to 500 m) in conditions of the CO extension. Over this measurement period the urban part of the CO content in the surface air layer over the city did not increase in spite of more than tripled number of motor-vehicles in Moscow.

Keywords:

carbon oxide; spectroscopy method; acoustic sensing; boundary layer