47261 – the peak maximum

51127 – the peak

maximum

Cycle 19

Cycle 18

Transition region Nr 19

47614 – the Gauss maximum

51216 – the Gauss maximum

48566 - the first spotless day

50329 - the last spotless day

49842 – the day in the middle of the longest (30 days) spotless segment.

Some definitions

The transition region is defined as the distance (denoted as d00) from the first spotless day after a cycle maximum to the last spotless day before the next maximum. This is the same definition as it was use to define so called the passive interval of solar activity in our paper Zięba et. al. ApJ 653:1517-1530, 2006. The name transition region is probably more adequate. The transition region number is taken from the number of the cycle before which this region is chosen.

Days are numerated from

the January 1, 1818.

The position of the longestspotless segment can be measured as a distance (ds0) from the first spotless day or as

a distance from the chosen maximum. Two different definition of a maximum are recognised. The peak maximum is

determined by the day with the maximal sunspot number while the Gauss maximum is described by the day in which

values obtained from observations after filtering using the 1080 day Gauss filter (presented as the red line) has the

maximal value. From the above defined points the following distances can be calculated:

dpx, dGx – the distances between the two successive maximums, peak or 1080 Gauss, respectively;

dp0, dG0 – the distances of the longest spotless segment from the left peak or 1080 Gauss maximum.

For the presented fragment of the data:

d00=1764 ; ds0=1277 ; dpx=3867 ; dGx=3603 ; dp0=2582 ; dG0=2229, which allows to calculate

the three different ratio r00=ds0/d00=0.724 ; rp0=dp0/dpx=0.668 ; rG0=dG0/dGx=0.619