Quick search Find article
Quick search
Find article

A Robust Correlation between Growth Rate and Amplitude of Solar Cycles: Consequences for Prediction Methods

FREE ISSUE

R. Cameron1 and M. Schüssler1

Show affiliations


We consider the statistical relationship between the growth rate of activity in the early phase of a solar cycle with its subsequent amplitude on the basis of four data sets of global activity indices (Wolf sunspot number, group sunspot number, sunspot area, and 10.7 cm radio flux). In all cases, a significant correlation is found: stronger cycles tend to rise faster. Owing to the overlapping of sunspot cycles, this correlation leads to an amplitude-dependent shift of the solar minimum epoch. We show that this effect explains the correlations underlying various so-called precursor methods for the prediction of solar cycle amplitudes and also affects the prediction tool of Dikpati et al. based on a dynamo model. Inferences as to the nature of the solar dynamo mechanism resulting from predictive schemes which (directly or indirectly) use the timing of solar minima should therefore be treated with caution.

Subject headings

Sun: activity


Dates

Issue 2 (2008 October 1)

Received 2008 May 19, accepted for publication 2008 June 14



View by subject




Export






Please login to access our web services, or create an account if you don't yet have one.

You must have cookies enabled in your web browser to be able to login.

Username
Password

Forgotten your password? Get a new one here.