Timo Niroma's answers on the"SolarCycle24" blog, November 2008

Answers I have given during November in the solarcycle24 blog:

Q: What is ahead?

A: The Sun glided into a chaotic phase between 1996.4-1996.8. The smoothed SSN in May 2000 was 121. So was cut the row of high maxima of cycle 21 and 22 with SSN 165 and 159. Actually this level had continued from the 1940's. Correcting the Jovian disturbance for cycles 19 and 20 (both had their minima 0.8 years after the Jovian perihelion) by taking the mean SSN for them as 156 and adding the maximum for the cycle 18 with SSN=152, the level dropped now from the 160 level with 25%. 

This is connected to the Gleissberg cycle, which waited with its minimum in 2005.8. The Gleissberg minimum cannot go below 72 years, so that was the last chance for cycle 23 to give way to the cycle 24. But then the cycle 23 would have lasted only 9.4 years which was not possible for a cycle which had already waisted 4 years to climb from minimum to maximum. 

So the cycle 23 had to continue, which changed the direction of the Gleissberg cycle from shortening to lenghtening. The shortening had began from the cycle 4, the cycle just before the Dalton minimum. The previous lengthening had began with cycle minus 9, just the cycle that began the Maunder Minimum.

In this way I leave the answer open. The past is not always a good basis for prediction, but sometimes it is.

Q: What do you see as the symptoms that would reverse the low trend in the Sun and cooling climate on Eart?

A: If the phenomenon that Penn and Livingston found (no sunspots in 2015 if the recent trend continues), reverse, if Ap index drop in 2005 will be temporary, if the solar conveyor belt gets a bit more speed, if the Gleissberg cycle has enough capability to say, this is enough, if that happens before the cycle change 23/24 is too near Jovian perihelion, if the TSI has an unexpected reverse from its downward trend (from 2005 continuous decrease below any observed during the satellite measurements since 1979), if the solar wind increases (2008 has had a 50 years mean low), then there are possibilities for decent cycles 24 and 25. But in case cows do not fly (at least a Finnish proverb), the cycles 24 and 25 are below Dalton level and the cooling of the Earth continues.

Q: How does the recent behaviour of the Sun compare how it has earlier behaved?

A: Every now and then there is a change in the mood of the Sun. Without going too far in the past I classify the most recent moods and their influence on our temperature as follows:

1645-1699 Maunder Minimum, virtually no spots for 55 years. Increasing cold here on Earth, the coldest period at least in 400 years, the coldest decade was the 1690's. The longer the minimum lasted, the colder it there was. Justin Schove has found similar occasions in the centuries AD200 and AD600, no spots, very cold.

1700-1766 Recovering Sun. Period begins most probably with a long cycle (13.5 years) and continues with only slightly disturbed cycles (estimated length 10.8 years). 

1766-1856 Restless Sun. Begins with two ultrashort cycles (about 9 years) which give for some years at least in the 1770's and at least in the Northern Europe temperatures achieved next only in the 1930's. According to 10Be measurements the 1770's is the least cloudy (most sunny) decade after 1700. Then follows the long cycle (13.6 years), which leads to Dalton Minimum (1798-1823, cold temperatures between 1801 and 1820). Oscillation continues to 1856.

1856-1913 Jovian dominated Sun. Of the five cycles 4 have a length of one Jupiter year. Colder than after 1913 and partly during the latter part of the 1700's.

1913-1996 Sun on its own. With one exception the cycles last as near 10.3 years as the circumstances allow (more appropriate measure methods would show this more clearly). Also the last cycle (cycle 22) is somehow disturbed in 1996. Warm, warmest in the 1930's and about 1985-2005. There are indications that the 1930's were warmer than the later period. The 1945-1975 period equals quite well with the 1770's at least in Uppsala, which I have used as a baseline on many occasions (not however after 1990 when UHI destroyed the continuity of one of the oldest and most reliable series of measurements (set up by Celsius himself in the first part of 1700's)). The heavy spottiness (I mean SSN(max) about 160) gives the possibility to warm climate, but as above in many posts have clearly been shown, PDO (at least) modulates effectively the end result. 

1996- Sun is in trouble in thinking how to behave now (more seriously: different influences upon Sun conflict with each other at the moment). On Earth the changing mood is seen as cooling. Oceans began to cool after 2003, atmosphere from 2005.

Timo Niroma