Radar Doppler and Faraday polarization measurements of the cislunar medium during the July 20, 1963, solar eclipse

Abstract

During the solar eclipse of July 20, 1963, changes in the columnar content of electrons in the total cislunar medium and in the earth's ionosphere were measured using radar Doppler and Faraday polarization techniques. At Stanford, where the maximum solar disk area covered by the moon was 23 per cent, the ionosphere decreased in content about 2 × 1016 electrons m−2 as compared with adjacent noneclipse days. The maximum eclipse effect occurred about an hour after maximum obscuration. A larger absolute change in electron content (2.8 × 1016 m−2) occurred beyond the ionosphere, but it is not yet possible to specify whether the cause was a blocking of the solar wind by the moon or some effect in the earth's magnetosphere above several thousand kilometers.