Experimental study of meteorological parameters variation using HF-signal during solar proton events

There are many experimental facts showing the influence of solar activity on weather and climate. Nevertheless, we still do not have a model explaining all the problems of solar-terrestrial links. This is due to the lack of experimental data about variations in meteorological conditions before, during and after a solar flare. This type of data could be obtained by use of, for example, weather balloon, rocket or aircraft sounding. However, achieving large arrays of continuous data by these methods is not possible due to their high cost. Refractive index, which plays a significant role in radiowave propagation, relates to the main meteorological parameters such as temperature, pressure and vapor pressure. Statistical studies of the signal level variation processes can therefore give some information about meteorological processes in the troposphere. An experimental radio link from the Asiasat-3S telecommunication satellite (elevation angle in Kharkov, Ukraine is 4.5/spl deg/) was constructed. The experiment was carried out from May 2002 to November 2003 at the frequency 3.6 GHz. More than 20 solar flare events were analyzed. The paper describes the scheme of the experiment and the results.