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A word about the duration of the Gore-Hansen Minimum.

First off, the day count was based the appearance of a Cycle 24 sunspot THAT MAY HAVE NEVER BEEN (it was not facing the Earth and it’s “detection” was by indirect means that are not accurate).

With that in mind, I’m bringing up the following data:

The current solar cycle, SC23, has been officially in progress since May of 1996 - or 147 months. The average length of solar cycles for the last 2 centuries is 133 months, so SC23 has been going on for 15 months LONGER than average (roughly 450 days).

However, each of the 5 previous cycles (SC18 to SC22) averaged only 125 months

There is a strong correlation between the length of solar cycles and global temperatures that I’ve heard expressed as “A cycle that is 4 months longer can be expected to yield a temperature lower by 0.1C .” Conversely, a shorter cycle correlates to global warming.

If you consider this correlation, you would expect a drop in global temperatures relative to the mean: not quite a .4C drop in mean temperature as things drag out.

This last is less than the observed drop in temperatures so the correlation may need adjustment or the relationship may be non-linear due to inherent time lag in the system (mainly because of the oceans).

In other words, both global warming and cooling may be predicted without considering the greenhouse effect as the principal cause.

Also, technically I could start saying that the Gore-Hansen Minimum is more than 450 days old ... if I wanted to.

My thanks to AFPhys for the heads up.

He posted a link to some discussion here: http://www.tmgnow.com/repository/solar/lassen1.html

Thank you for the ping. Sorry I’ve been away.

I’ve been interested in this correlation of cycle length to earth’s temp for some time now. I have to say that I was incredibly skeptical when I first ran across the suggestion that cycle length could even BE correlated, however, I’m now convinced that is the easiest and most accessible parameter we have now. I’ve been keeping track of this, and occasionally posting about it, for a couple years now. That Lassen paper I linked is a good summary, but not the only study of the cycle length vs. temp.

The one and only part that I’m really fuzzy about is the “lag time”, or “phase” relationship with temp vs. length. Clearly, the is one. I’m believing that using about a 25yr cycle length average, and a 5 yr lag of temp with that is on the order of reasonable. There are, however, definite VERY long time lags that get built in by the “Ocean Conveyor” and probably other ocean mechanisms as the heat that gets absorbed by the oceans is transported lower and then back up again. ... and who knows what other absorption/release mechanisms can result in delays or buffering of some type? Those really make it difficult to figure out what is going on. One certain thing is that this can be correlated to the bulk of the temperature changes seen the last two centuries.

Thanks for this thread, and the GoreHanson Minimum watch.