The Sunspot Observer - Visual indices of solar activity

Statistics of sunspot activity

Visual indices of solar activity


N - number of observes for month
W - Wolf number
Wn - Wolf number of northern hemisphere
Ws - Wolf number of southern hemisphere
n - number of spot groups
A - Waldmeier class of unipolar spot groups without penumbra
B - class of bipolar spot groups without penumbra
C - class of bipolar spot groups with one penumbra pole
D - class of small bipolar spot groups with two penumbra poles
E - class of middle bipolar spot groups with two penumbra poles
F - class of big bipolar spot groups with two penumbra poles
G - class of old bipolar spot groups with isolated poles
H - class of unipolar penumbrated spot groups
I - class of small unipolar penumbrated spot groups
x - class of spots without penumbra
r - class of rudimentar penumbrated spots
s - class of small symmetrical penumbrated spots
a - class of small asymmetrical penumbrated spots
h - class of big symmetrical penumbrated spots
k - class of big asymmetrical penumbrated spots
x - class of unipolar spot groups
o - class of open bipolar spot groups
i - class of half-open bipolar spot groups
c - class of close bipolar spot groups
CV - Classification Values after Malde
gr - Inter-Sol number of spot groups
grfp - number of penumbrated spots as group members
grf - nubmer of spots without penumbra as group members
efp - number of single penumbrated spots (out of groups)
ef - number of single spots without penumbra (out of groups)
Cond - observing conditions