ИСТИНА

The measurements of special wind parameters including vertical wind component velocity W and its standard deviation σw are connected with specific methodical problems, unlike measurements of full wind vector which reliability is usually high. In autumn of 2008 four sodars (‘M300C' produced by AeroVironment, ‘ECHO-1’ produced in GDR, ‘MODOS’ produced by METEK and ‘MFAS’ produced by Scintec) operated simultaneously during one month at close vicinity of the 310 m height meteorological mast (at distances from 100 to 800 m from it). Sodars ‘MODOS’ and ‘MFAS’ are Doppler (three-antennas and phase-array antenna correspondingly) whereas two others (‘ECHO-1’ and ‘AeroVironment’) are one-channel vertical sodars which are supplied by special Doppler add. The mast was equipped by sonic anemometers at three levels – 16, 217 and 265 m height. All collected data about W and σw were analyzed and compared with each other on a base of both 10 min and 1 hour temporal averaging. As a result any relations of measured W values between different data sources (four sodars and mast anemometers) are comparatively weak or middle (the highest correlation co-efficient is 0.62). Nevertheless, some of them are statistically significant. For the same sources of data (one of sodars and mast) the higher is a comparison level the closer as a rule relation is. For the data of W averaged on 1 hour relations are closer than for the data averaged on 10 min. Similar relations between σw data are in general closer than for W values but not excellent as well. The diurnal courses of both W and σw values are discussed; they demonstrates a weak daily maximum which seems to be not significant. Direct measurements are supposed to be more accurate than the remote ones. However, as it shown, in situ measurements of W are connected with some specific errors. Among others, a clear relation between W values by the data of mast anemometer and wind direction was found. Probably it is a result either of the mast body dynamical influence or of the anemometer axis incline. Moreover, non-flat terrain in vicinity of the mast (total relief incline) probably creates an additional systematic error of W measurements as well. Methodical analysis of real accuracy of the vertical wind component measurements is carried out. Besides a historical review about measurements of W by different tools since the 19th century has been presented at the report.