Correlation of coronal and geomagnetic Observations, 1944–1946

Abstract

Observations of the solar corona in 1944–1946 are analyzed with reference to geomagnetic disturbance, extending an earlier investigation by Shapley and Roberts [1946] for the period 1942–1944. Coronagraphic data from Climax are now supplemented by observations from two European observatories. The intensity scales of the green emission‐line of the coronal spectrum at the three observatories are intercompared, and the regions of activity in the corona are identified from the combined observations. The coronal‐geomagnetic correlation has become weaker since minimum epoch of the sunspot cycle in 1944 and the apparent time relationship has shifted.