R. K. Shivpuri^* and M. R. Cruty^†

• Physics Department, Clarkson College of Technology, Potsdam, New York 13676

P. J. McNulty^‡

• Space Physics Laboratory, Air Force Cambridge Research Laboratories, L. G. Hanscom Field, Bedford, Massachusetts 01730 and Physics Department, Clarkson College of Technology, Potsdam, New York

• ^*Present address: University of Delhi, Delhi, India.
• ^†Present address: University of San Francisco, San Francisco, California 94117.
• ^‡NAS-NRC Senior Resident Research Associate—Present address: Brookhaven National Laboratory, Upton, New York 11973.