Scale-size calculations, energy dissipation rates and height coverageof a 404 MHz wind profiler at IMD, Pune

摘要

The 404 MHz wind profiler at the India Meteorological Department, Pune, is the first wind profiler of thisfrequency in India. Therefore, it is necessary to achieve maximum possible height to get valuable data. UHFwind profilers have better height and time resolution, which enables us to make reliable and correct estimationsof the wind at various altitudes at regular spacing above the observational site. The height coverage ofthe profiler depends upon various factors like power aperture product and the operating wavelength vis-avisscale sizes available in the atmosphere. In this study, daily averaged second moment data archived duringclear-air conditions have been used to estimate the scale-size parameters in terms of eddy dissipationrates, which explicitly indicates that more height coverage of a profiler depends only on the availability ofthe scale sizes in the atmosphere to which the radar is sensitive, and that in turn depends on where in theinertial subrange the operating wavelength resides. Power aperture product at various C2nvalues has been estimated. This note explicitly explains why the height coverage of the wind profiler at Pune is limited to 6–8 km under clear-air conditions.