Relation between the Visibility of Jupiter's Red Spot and Solar Activity

Abstract

THE visibility of Jupiter's red spot in relation to solar activity has recently been widely discussed in a series of letters. The original claim of dependence of the red spot on ultraviolet radiation from the Sun noted by Graf, Smith and McDevitt¹ for the period 1892–1947 was discarded by Argyle² on the basis of very low value of correlation coefficient (r = 0.27) between the visibility (V) and Zurich relative sunspot number (R_z). The inclusion of recent observations of Jupiter by Reese in the analysis of Solberg and Chapman³ extends the data to 1967 and shows even a lower value of the coefficient of correlation (r = 0.16). The use of some other aspect of solar activity instead of sunspot numbers—such as solar particles, suggested by Scott Smith⁴—is not suitable, for necessary data are not available as far back as 1892. Because the sunspot is known as the index of both wave as well as particle radiations from the Sun, however, a re-investigation of the relationship with the only available sunspot data was considered worthwhile.