On the relationships between sfe (crochet) and solar X-ray and microwave bursts

Abstract

Geomagnetic crochets (sfe) observed at Kodaikanal over the period 1966-71 have been studied in relation to solar X-ray bursts observed by NRL satellite (SOLRAD-9) in the 0.5-3 A, 1-8 A and 8-20 A bands and radio bursts observed in the frequency range 1000-17000 MHz. The amplitude of sfe is linearly correlated with the peak intensities of X-ray bursts in the 1-8 A and 8-20 A bands. The single frequency correlation of sfe with radio bursts is a flat maximum in the frequency range 2000-3750 MHz. Following the spectral classification of AFCRL for microwave bursts, it is noticed that sfe are mostly associated with the 'A' type burst spectra and are very poorly correlated with bursts with the 'G', 'C' and 'M' type spectra. These features differ from those of other SID's reported earlier.