Forecast of the Decadal Average Sunspot Number |
| |
| Authors: | D M Volobuev N G Makarenko |
| |
| Institution: | (1) Pulkovo Observatory, St.-Petersburg, Russia |
| |
| Abstract: | The forecast of the decadal average sunspot number (SN) becomes possible with an extension of telescopic observations based
on proxy reconstructions using the tree ring radiocarbon data during the Holocene. These decadal numbers (SNRC) provide a powerful statistic to verify the forecasting methods. Complicated dynamics of long-term solar activity and noise
of proxy-based reconstruction make the one-step-ahead forecast challenging for any forecasting method. Here we construct a
continuous data set of SNRC which extends the group sunspot number and the international sunspot number. The known technique of nonlinear forecast, the
local linear approximation, is adapted to estimate the coming SN. Both the method and the continuous data set were tested
and tuned to obtain the minimum of a normalized average prediction error (E) during the last millennium using several past millennia as a training data set. E=0.58σ
D is achieved to forecast the SN successive differences whose standard deviation is σ
D=7.39 for the period of training. This corresponds to the correlation (r=0.97) between true and forecasted SN. This error is significantly smaller than the prediction error when the surrogate data
were used for the training data set, and proves the nonlinearity in the decadal SN. The estimated coming SN is smaller than
the previous one. |
| |
| Keywords: | Solar activity Nonlinear forecast Radiocarbon |
| 本文献已被 SpringerLink 等数据库收录！ |
