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.
The solar cycle is important because it is a indicator of solar activity. There is correlation between earth temperatures and solar activity and as you note a time lag is involved, but sometimes there is deviation from the solar activity rhythms. There are additional Earth based factors. For example, volcanic eruptions on land can cool the lower atmosphere, while volcanic eruptions under water can warm the oceans.