Open Access

Fig. 1.

image

Download original image

Annual variations of the yearly averaged sunspot numbers (Solar Influences Data Analysis Center (SIDC) at the Royal Observatory of Belgium) (version 1.0) (blue solid line) and the HCS tilt angle, α, (green dashed line) for the period 1976–2014. The correlation coefficient between the two is .

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.