THE 73-DAY PERIODICITY OF THE FLARE INDEX DURING THE CURRENT SOLAR CYCLE-22

The flare index of the current solar cycle 22 is analysed to detect pe riodicities. Power spectral analysis of the time series of solar flare index data reveals a periodicity around 73 and 53 days. We find that a periodicity of 73 days was in operation from November 1988 to the en d of December 1991. We also find that when the 73-day periodicity or t he 154-day periodicity is in operation the flare index is well correla ted with the relative sunspot numbers.