Latitude migration of solar activity at high latitudes

Utilized here is the Carte Synoptique solar filament archive, namely the catalogue of solar filaments from March 1919 to December 1989, corresponding to solar rotation numbers 876 to 1823 to study latitudinal migration of solar activity at high latitudes. Except the well-known poleward migration of solar activity from middle latitudes to the poles, an equatorward migration is found from the solar poles toward middle latitudes (about 40°) within a normal cycle, which is neglected before, and the time interval for the former migration (4.4 years) is about 2.2 years shorter than that for the latter (6.6 years), indicating that the change from one migration to the other takes place around the maximum time of a normal cycle. In the future, a dynamo model should represent the migration from the poles toward middle latitudes of the Sun, besides the migration in “butterfly diagrams” and the “rush to the poles”. The traditional extended activity cycle is actually a part of the period of the successive migration from the poles toward the solar equator. Supported by the National Natural Science Foundation of China (Grant Nos. 40636031 and 10573034), the State Key Development Program for Basic Research of China (Grant No. 2006CB806300), and the Chinese Academy of Sciences Project (Grant No. KJCX2-YW-T04)