BLOG: How does a cooler sun yield a warmer earth?

BLOG: How does a cooler sun yield a warmer earth?

CHARLOTTE, NC (WBTV) - For a long time I pondered why the earth tended to be warmer when we were experiencing an active sunspot cycle.

Sunspots are darker and cooler regions on the sun's surface (photosphere). So how is it that when the sun is pockmarked with cooler regions, it is producing more heat to warm the earth?  Well it isn't.

Those sunspots are indicative of intense magnetic storms, which also eject large magnetic fields toward earth. Now hold that thought.

We are also being bombarded by other stuff - I mean the list goes on and on – gamma rays, x-rays, cosmic rays, etc, etc.  I am going to focus on cosmic rays.  Scientists are still uncertain about the origin of these subatomic particles hurling through space, but the leading theory is they form from supernovas, which are exploding stars.

Cosmic rays are the highest-energy particles found in nature.

A strong theory by a number of scientists suggests that cosmic rays entering the earth's atmosphere actually ionize molecules and create particles and aerosols that act as seeds (condensation nuclei) for water droplets to form and grow into clouds.

With more clouds in our atmosphere, the planet is cooler as the clouds reflect the sun's light away preventing it from heating the earth.

So here is where the sunspots become important. The strong magnetic field they produce (sometimes called solar storms or coronal mass ejections) reach the earth and actually deflect or block the cosmic rays.

With the cosmic rays blocked, the theory proposes we have fewer clouds, therefore more sunshine and more heat and a warmer planet. Whether or not this theory is correct is still up for debate, but there is little question about the correlation between sunspots and the earth's rising and falling temperature.

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