Does High-Latitude Solar Activity Lead Low-Latitude Solar Activity in Time Phase?

Using data from the Carte Synoptique solar filaments archive, we investigate whether there is a time lag between high-latitude solar activity and low-latitude solar activity. The cross-correlation analysis of the number of high-latitude filaments per Carrington rotation (NHF) and that of low-latitude filaments per Carrington rotation (NLF) shows, although inconclusively, that NLF possibly lags behind NHF. The periodic characteristics of both NHF and NLF clearly indicate that the activity of high-latitude filaments is evidently leading the activity of low-latitude filaments. Thus, the present study suggests that high-latitude solar activity leads low-latitude solar activity in time phase.