Solar Science

A blog of solar physics

Archive for September 2007

Predictions of Solar Cycle 24: Clilverd et al

with 4 comments

A paper published in Space Weather in 2006 used a relatively simple numerical model to add together the known solar cycles of various lengths (including the true solar cycle which is ~22 years) to produce this result:

sunspots-clilverd-etal.JPG

Now from my perspective this is ho-hum in terms of solar modelling. The underlying cycles consisted of a wave groups with constant periodicity, something that really doesn’t happen in the real solar system.

underlyingcycles-clilverd-et-al.jpg

In the real solar cycle, the cycle itself varies in length, shorter cycles being associated with climatic warming on Earth, longer cycles (>12 years) associated with cooling.

The conclusion of the authors is clear. Both solar cycle 24 and 25 are likely to be weak, Dalton-minimum style affairs. But will we get Dalton-minimum style climate cooling? Only time will tell…

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Written by John A

September 10, 2007 at 12:22 pm

Posted in Solar Cycle 24

Still no sign of Solar Cycle 24

with 7 comments

Here’s the latest trend chart from NASA. Apparently the Sun knows nothing of the predictions of NASA solar scientists regarding solar cycle 24.

Today’s pictures of the Sun show an absolutely featureless disk:

featurelesssolardisk.gif

and the magnetogram shows absolutely no sign of any magnetic activity

feratureless-magnetogram.gif

I’ve no idea what this portends for the Earth’s climate so we’ll just have to see what happens next.

Written by John A

September 9, 2007 at 9:11 pm

Posted in Solar Cycle