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Can any of the physics gurus here offer an explanation of how sunspot activity is related to heat output? It doesn't really explain that in the article. Less he

Can any of the physics gurus here offer an explanation of how sunspot activity is related to heat output? It doesn't really explain that in the article. Less heat output means less fusion reaction, means less magnetic activity, means lack of sunspots, I presume?

ajju 18y ago
I know. Without even speculation on how they are related except some temporal correlation, I am inclined to discount this as idle fearmongering
- hugh 18y ago
  From the wikipedia article on sunspots: Since sunspots are darker than the surrounding photosphere it might be expected that more sunspots would lead to less solar radiation and a decreased solar constant. However, the surrounding margins of sunspots are hotter than the average, and so are brighter; overall, more sunspots increase the sun's solar constant or brightness.
  - river_styx 18y ago
    But if this were the cause, wouldn't sunspots put our global temperature in constant flux as the spots themselves migrate and as we orbit and move toward/away from them?
    - ars 18y ago
      The earth is a tremendous heat sink. The oceans especially will buffer huge amounts of change in temperature.
ars 18y ago
The sun is actually a very good insulator. All the heat is generated in the middle and takes millennia to reach the top. So anything that basically "mixes" the sun will cause more heat to be emitted. No sun spots=no mixing, and all the heat remains trapped. I think that after trapping heat for so long, the sun gets hotter and generates more sun spots because of all the extra energy. The sun spots bleed it out, and the cycle continues.
- ced 18y ago
  Uh, what? Sun spots come from the magnetic flux tubes from the inner layers becoming unstable and rising to the surface, forming loops. If anything, I'd guess that sunspots inhibit the flow. The mixing happens mostly because of the persistent convection cells in the sun and of course the turbulence. I don't know offhand the answer to the parent's question, but in my experience, the above doesn't make sense.
  - ars 18y ago
    Convection cells are the baseline mixing, but any activity in the sun, and sun spots are far from quiet areas, despite being dark, would cause additional mixing. Why would you say sunspots would inhibit the flow? "magnetic flux tubes" would not arise from nothing, they would arise from large amounts of ions moving (making an electrical current), and therefor mixing the suns layers.
ced 18y ago
The magnetic activity doesn't come from the fusion reaction directly. The sun has a differential rotation profile. Some layers rotate faster than others. This stretches the magnetic flux tubes as they pass through these layers, increasing their strength. If you drop some oil in a river which is not moving at a uniform speed, the oil spot will get deformed and stretched. (it sounds like voodoo magic, I hate that explanation, but it's the textbook version as far as I can remember)

ajju 18y ago

I know. Without even speculation on how they are related except some temporal correlation, I am inclined to discount this as idle fearmongering

hugh 18y ago
From the wikipedia article on sunspots: Since sunspots are darker than the surrounding photosphere it might be expected that more sunspots would lead to less solar radiation and a decreased solar constant. However, the surrounding margins of sunspots are hotter than the average, and so are brighter; overall, more sunspots increase the sun's solar constant or brightness.
- river_styx 18y ago
  But if this were the cause, wouldn't sunspots put our global temperature in constant flux as the spots themselves migrate and as we orbit and move toward/away from them?
  - ars 18y ago
    The earth is a tremendous heat sink. The oceans especially will buffer huge amounts of change in temperature.

ars 18y ago

The sun is actually a very good insulator. All the heat is generated in the middle and takes millennia to reach the top. So anything that basically "mixes" the sun will cause more heat to be emitted. No sun spots=no mixing, and all the heat remains trapped. I think that after trapping heat for so long, the sun gets hotter and generates more sun spots because of all the extra energy. The sun spots bleed it out, and the cycle continues.

ced 18y ago
Uh, what? Sun spots come from the magnetic flux tubes from the inner layers becoming unstable and rising to the surface, forming loops. If anything, I'd guess that sunspots inhibit the flow. The mixing happens mostly because of the persistent convection cells in the sun and of course the turbulence. I don't know offhand the answer to the parent's question, but in my experience, the above doesn't make sense.
- ars 18y ago
  Convection cells are the baseline mixing, but any activity in the sun, and sun spots are far from quiet areas, despite being dark, would cause additional mixing. Why would you say sunspots would inhibit the flow? "magnetic flux tubes" would not arise from nothing, they would arise from large amounts of ions moving (making an electrical current), and therefor mixing the suns layers.

ced 18y ago

The magnetic activity doesn't come from the fusion reaction directly. The sun has a differential rotation profile. Some layers rotate faster than others. This stretches the magnetic flux tubes as they pass through these layers, increasing their strength. If you drop some oil in a river which is not moving at a uniform speed, the oil spot will get deformed and stretched. (it sounds like voodoo magic, I hate that explanation, but it's the textbook version as far as I can remember)