Dr. Svalgaard, Do you know of any datasets on rotational rates by latitude as solar cycle progresses? Do eddy current wax/wane over the cycle? Does differential rotation change through the cycle like TSI?
On the 15th of this month, sunspot number 2239 has gained notoriety for exhibiting 'negative polarity' characteristics. It is being suggested this is a symptom of magnetic values falling below 1500 gauss.
Could you offer a scientific observation on this event?
Kind regards, and many thanks for your resource page, your openness with your research is appreciated!
Dr. Leif, are you aware of this actual paper www.csnsm.in2p3.fr/IMG/pdf/science-2015-cameron-1333-5_solar_dynamo.pdf which gives the statistical method of forcast the SSN-max of the next SC with the help of the polar fields during the SSN min before more physical basics? In this context: We are now about 2 years after the reversal of the smoothed fields according to this data: wso.stanford.edu/Polar.html and I made a comparison with historical data from 1900 on ( doi:10.1088/0004-637X/753/2/146 ) about the strength of N-S/2 two years after the reversal ( SSN-max) with the result that the latest data ( mean October 14- March 15) reach only about 40% of the lowest values since 1900. ( SC 14,16,18) and are well below the st.dev. of this data. I know, I asked this question some month ago, anyway...time is running for the development of the polar fields for the next SSN-minimum as a proxy for the Max. of SC25. Do you habe a look at this phenomena? best Frank
The Cameron paper cites our 1978 paper as giving the best method for prediction of the sunspot number. The physical bases has already long been firm: Leighton, Choudhuri, etc. Cameron et al. agree with this which is nice. As for prediction of the next cycle, it is a bit too early. The polar fields should first stabilize and the North polar fields are not quite there yet.
Hello Dr Svalgaard, just wondering where your thoughts are regarding the L&p effect, during the recent solar maximum the curve noticeably flattened and it initially appeared that it may reverse....is this what you'd expect or may it continue its previous course as we proceed to the next minimum?