On 3 to 6 year cycles in the time of geomagnetic storm sudden commencement occurrence and ENSO climate cycles

Abstract. The geographic longitude of the subsolar meridian (SML) evaluated at the time of geomagnetic Storm Sudden Commencement (SSC) occurrence shows an unexpected organized longitudinal progression with time, for successive SSC events. The progression includes, in particular, quasi-periodic cycles of about 3 to more than 6 year duration which show a close relationship with the sunspot cycles. The 3 to 6 year SML cycles also show a surprising agreement with the naturally occurring climate cycles known as El Nino/Southern Oscillations (ENSO). On the basis of SSC and El Niño records from 1968 to 2003, it is found that a warm ENSO phase (El Niño) takes place at about the middle of each of seven identified SML cycles.