Solar minumim...

[astromark]

Not a sunspot for months. We had a observing the sun by daylight, ( Oddly enough its hard to find at night.) Understandably some of the public were disappointed. ' Its just white.' and it was. but I see today the BBC ran a article claiming this in-activity might sagest good old Sol is dimming... NOT SO I would argue. Sunspot activity and solar prominences are not signs of extra heat. The opposite would be the case. Sun spots are cooler areas. So if there are none would that suggest cooling ? I do not think so. Could this be discussed,?
Can the output be measured,?

[grant hutchison]

We've now tracked solar irradiance very precisely through a couple of solar cycles, and the energy output of the sun does seem to increase at sunspot maxima and decrease at sunspot minima.
IIRC, the suggestion is that the concentration of faculae around each sunspot puts out more energy than is "lost" because of the cool sunspot itself.

Grant Hutchison

[tusenfem]

tomorrow at the JENAM (http://www.jenam2009.eu) meeting there are two sessions about the "The unusual (?) solar minimum" and on friday a session on solar dynamo processs. looks like it's going to be interesting. if I find the time I will report later.

[Cougar]

...if I find the time I will report later.

We're counting on you, Tusie. :)

[dgruss23]

Not a sunspot for months. We had a observing the sun by daylight, ( Oddly enough its hard to find at night.) Understandably some of the public were disappointed. ' Its just white.' and it was. but I see today the BBC ran a article claiming this in-activity might sagest good old Sol is dimming... NOT SO I would argue. Sunspot activity and solar prominences are not signs of extra heat. The opposite would be the case. Sun spots are cooler areas. So if there are none would that suggest cooling ? I do not think so. Could this be discussed,?
Can the output be measured,?

As Grant explained, Total Solar Irradiance (TSI) actually increases at sunspot maximum. The change is not much, but it does correlate with climate fluctuations on Earth. The reason for the increase in TSI does have to do with faculae - which are regions of higher energy output on the suns surface. The suns magnetic activity overall increases at sunspot maximum and this may have some indirect effects on the Earth's climate.

[astromark]

Thanks for this information... to be informed is good.

[tusenfem]

Tusie????????

Okay, this morning was the first session, and it all became rather specialistic at a point. However, several points that struck me as interesting were:


Looking at the magnetic field strength on the surface of the sun, there is little difference with "normal" cycles, but there ARE differences, and as expected, they are at the end of the cycle
Looking at bands at the middle of both hemispheres and comparing the magnetic field in it with the region around the equator shows that the northern hemisphere is basically the same but there is a significant difference in the southern hemispere
This also comes out clearly in the butterfly diagrams of the magnetic field, where the northern "wing" is the same (basicaly) for 21 22 and 23, however, the southern "wing" is longer and more intense for 23 as compared with 21 and 22
Also, the solar magnetic field has not yet returned to a dipole field, which is usual for the real solar minimum
What could be important is that the sun is on its way to exit the period of GSM (Grand Solar Maximum). As the last time this occurred was before the space age, we do not know what "is supposed to happen" at that point. The estimate was that the GSM would end in 9 +/- 8 years, so it could be happening soon
The UV emission of the Sun has not changed at all, which is interesting as the other parameters have changed a lot (being "dimmer", solar wind less magnetic field strength and less ram pressure because of lower density). The ratio of He of H has not changed.


Basically, the feeling was that we are in a very very interesting time of solar physics. Everything is being measures, and this is the first time in the space age that we have an anomalous minimum and that we are leaving a GSM (if I am not mistaken, the entry into GSM was before the space age), so let's see what happens.

Another interesting topic was about global warming and the sun, which was basically inconclusive and now someone is talking about cloud cover and solar parameters and cosmic rays (he denies that there is a link with the latter).

Okay, gotta listen now.