70 likes | 191 Views
Progress in Reconstructing Solar Wind Magnetic Field back to 1840s. Svalgaard 2014. Using u -measure. Even using only ONE station, the ‘IDV’ signature is strong enough to show the effect. As the Sunspot Number is used as Model input it is important to get that right.
E N D
Progress in Reconstructing Solar Wind Magnetic Field back to 1840s Svalgaard 2014 Using u-measure Even using only ONE station, the ‘IDV’ signature is strong enough to show the effect
As the Sunspot Number is used as Model input it is important to get that right • Four recent Sunspot Number Workshops (2011-2014) have critically examined the historical sunspot number record(s) • There is now broad consensus among the participants that we have identified the major problems with the SSN series: • A) Error (65%) in Wolf-Wolfer calibration for the GSN before ~1882 • B) Weighting of sunspot counts (20%) for the Int. SSN starting in 1940s
Counting with no Weighting 1 6 2 9 1 xx 19 5x10+44=94 5x10+19=69 94/69 = 1.36 Recounted 2003-2014: ~55,000 spots
Effect on the Wolf Number Factor to remove weighting 0.8535 [inverse of 1.17]
SSN4: No Modern Grand Maximum The preliminary new sunspot record expressed in terms of the number of sunspot groups. Of note is that there is a maximum in every century, none of them particularly ‘Grand’. The new Wolf Number should be used as model input and we should understand the behavior and the fit of the model to the new perspective and to HMF B before we can extrapolate with any degree of confidence to the Maunder Minimum.
No Rising Background ‘Base Level’ Open Flux TSI (LASP) Corr. SSN GSN
Perhaps the Maunder Minimum was Less Extreme than we Thought The emergence of ‘ephemeral regions’ does not show any solar cycle dependence [e.g. Hagenaar, 2008], thus no ever-increasing background