Sunspot motions from a study of Kodaikanal and Mount Wilson observations

Abstract

Results are presented of a study of the daily motions of individual sunspots and of sunspot groups on the basis of Kodaikanal and Mount Wilson white-light observations. A comparison of the two data sets show a good agreement between them in spot areas and motions. Preliminary rotation and latitude drift reduction from the combined data set confirm earlier results from the Mount Wilson data alone.