Monday, April 27, 2009

A Clean Sun

Yes. Space Weather Dot Com says the sun is still very clean. That is to say spotless. The spotlessness of the sun has become so interesting to the general public that they have added some new numbers about spotless days to their daily sunspot number. Which is zero today. The added information looks like this today:

Current Stretch: 6 days
2009 total: 103 days (88%)
Since 2004: 614 days
Typical Solar Min: 485 days

So what to expect next? No one knows for sure since, like climate, the exact nature of what is going on in the sun is not fully understood. And even if we thought we understood it, new information could turn up that would invalidate our current understanding. Because - unlike colonies - science is never settled.


rumcrook said...

when I was a kid we used to have some doozies when it came to cold winters with lots of snow...

if the sun is the culprit for much of the warming that has now been disapating for the last few years, than a few of my friends who think millions will die becuase of global warming and the economy will be destroyed are gonna have egg on thier faces,....

less sun activity less radiation? less heat? cooler winters and summers?

LarryD said...

Total insolation varies by a minuscule amount, however the UV output difference is big enough to be significant.

Also, a quiet sun generates a slower, weaker solar wind. And there are major differences in the solar magnetosphere.

The hypothesis that this quiet sun is allowing us to put to the test, is that an active sun deflects galactic cosmic rays (GCRs) and a quiet sun lets more through. GCRs are believed to promote clouds in the lower atmosphere, which would increase Earths's albedo, resulting in cooling.

I'm old enough to remember the "coming ice age" hysteria accompanying a cooling trend back in the 1970s. And what do you expect after a cooling trend? Right, a warming trend. Which has ended, and we're cooling again. And the "impending ice age" meme has resurfaced already. A reasonable concern, however, is that we might be entering a multi-decade cooling period like the Dalton Minimum. We just don't know enough about solar cycles to to be sure.

Tom Cuddihy said...

And now for the apocalyptic literalist minded:

Rev 8:12 "When the fourth angel blew his trumpet, a third of the sun, a third of the moon, and a third of the stars were struck, so that a third of them became dark. The day lost its light for a third of the time, as did the night."

How large an increase in cosmic radiation flux would be required to increase lower troposphere cloud cover by 1/3 from 1990s optimums?