A Study of Field Aligned Irregularities from Three Observation Points

摘要

An investigation of field aligned irregularities was performed using 18 Mc/s backscatter radar data from Washington State University, Stanford University, and the Plum Island Site of the Air Force Cambridge Laboratories. Differences were found in the field aligned echo occurrence patterns at the three stations. A definite latitudinal difference of diurnal variation existed. WSU and AFCRL had peaks of field aligned activity in 1964 at a time near sunset while Stanford University's peak occurred at the time of midnight. Seasonal variation of FAE activity at WSU and AFCRL indicated peaks of activity during the summer for the quiet period of the solar cycle. Solar cycle variations at WSU included changes in the daily and seasonal times of peak occurrence of recorded FAE's. In 1958, WSU had the diurnal peak of activity at midnight and the seasonal peaks at the time of the equinoxes. Field aligned echo observations at these three stations are in general agreement with other methods of observing field aligned irregularities, particularly previous high-latitude Spread-F observations. (Author)