An improved correlation between maximum sunspot number (SSNM) and the preceding minimum (SSNm) is reported when the monthly mean sunspot numbers are smoothed with a 13-month running window. This relation allows prediction ...

It is well known that the daily international magnetic character figure Ci constitutes a valuable index for classifying days according to their magnetic activity averaged over a large part of the earth. As a measure of the ...

The `sunspot occurrence probability' defined in Paper 1 is used to determine the Legendre-Fourier (LF) terms in the `rate of emergence of toroidal magnetic flux, Q(theta, t), above the photosphere per unit latitude interval, ...

The solar equatorial rotation rate, determined from sunspot group data during the period 1879 2004, decreased over the last century, whereas the level of activity has increased considerably. The latitude gradient term of ...

Using ionogram data at Kodaikanal (geomagnetic lat. 06 deg N, Dip 3.5 deg N) over a seven year period, Jan. 1957-Dec. 1963, a study is made of the seasonal and sunspot cycle variations in the nocturnal occurrence of amplitude ...