Alibag Magnetic Observatory July to September, 1948

(Latitude 18° 38′.3 N., longitude 72° 52′.3 or 4 h 51 m .5 E. of Gr.) August 7–11 —A magnetic storm of moderate intensity commenced suddenly at 22 h 59 m GMT, August 7, with a sharp rise of 25 gammas in H , an insignificant rise followed by a fall of 7 gammas in Z , and an increase of 0′.7 in westerly D , all in about two minutes. After a period of slight intensity lasting for about four hours, H decreased rapidly till about 10 h , August 8, and thereafter recorded some rapid fluctuations for about five hours. This was followed by a laboured rise which was interrupted by frequent rise and fall. Throughout August 9 the intensity of the storm was slight but at about 05 h , August 10, it became more intense and rapid fluctuations were recorded till about 09 h 30 m ; after about 12 h , large‐amplitude fluctuations were recorded till about 20 h .