Why Doesn't the 11-Year Solar Cycle Affect the Sun's Magnetic Field?

[Frank Einstein]

Hello everybody.

After reading about solar variability in the past I have found that the eleven year cycle of solar activity doen't affect the magnetic field of the sun so it is impossible to know the distribution of sunspots previous to 1610, when the observation started.

But on the other hand, the proxies of 14C and 10Be can be used to calculate the long term variability of the sun. I don't understand the reason of the lack of effect of the 11 year cycle on the solar magnetic field. I have read that is related to the fact that this cycle only affect to closed field lines and they compensate between each other, but I don't understand much else.

Can somebody please point me to some source where this is clearly explained?

Thanks for reading.

 

[davenn]

After reading about solar variability in the past I have found that the eleven year cycle of solar activity doen't affect the magnetic field of the sun so it is impossible to know the distribution of sunspots previous to 1610, when the observation started.

not sure what you have been reading ?? what do you mean ... "doesn't affect " ?
the magnetic field of the spots reverses every 11 years

every 22 years there is a complete reversal of the solar magnetic field

 

[Frank Einstein]

not sure what you have been reading ?? what do you mean ... "doesn't affect " ?
the magnetic field of the spots reverses every 11 years

every 22 years there is a complete reversal of the solar magnetic field

I have read that the amount of sunspots can only be known until 1610, when astronomers started to record them, that's why articles such as Lean et al (1995) only show roughly 400 years of sunspots and not a longer timescale.

Anyways. Thank for your anwser.

 

[davenn]

I have read that the amount of sunspots can only be known until 1610, when astronomers started to record them, that's why articles such as Lean et al (1995) only show roughly 400 years of sunspots and not a longer timescale.

Anyways. Thank for your anwser.

but that didn't answer my question
you said there isn't a magnetic cycle ( well what you were reading said...)
but there is one

 

[Ken G]

It sounds like you are trying to connect the long-term variations in the solar luminosity with long-term changes in the sunspot number (and you are saying "magnetic field" when you mean "sunspot number" because you know sunspots are regions of high magnetic field, but note that sunspots don't care about the direction of the field, whereas the field itself does, and what's more, sunspots only appear in the regions of highest field, they don't tell you about the average field, so you are assuming the sunspot number correlates with variations in the average field). That is indeed impossible, since we only have proxies for the solar luminosity variation, not the magnetic field variation. There would be no point in taking the correlations we have observed and extrapolate them into the past, because then you would only get out the assumptions you put in, and what purpose would that serve? Also, it's not clear why you care about the 11 year cycle at all, because it's a cycle-- the field repeats in strength and direction every 22 years, so what would that have to do with long-term changes? Whatever is causing the cycle could have nothing at all to do with long-term variations.