Bob H left me the following comment on a recent post, and by the time I was done responding, I decided that I’d make it a post. May as well reward my long-windedness with another blog entry:
EDITED COMMENT: Upon a re-read of this, I realized that Bob refers to the Solar Retrograde cycle in the comment, and for some reason my brain read that as precession of the earth’s axis. Why I saw that, I have no idea, since it’s not even close. I blame Brett Favre. In any case, I’ve revisited some of the cycles and my understanding of them below. it really is kind of a random post.
Also, Bob… one of these days I still intend to get to your guest post submissions.
“Good Morning Joe,
I remember Robert Felix referring to the solar retrograde cycle. It’s length has been measured at (correct me if I’m wrong) about 180 years, and he referred to another cycle at 360 years. Your analysis matches well with this time scale, especially since it is based on 60 years of data. It’s a little short, but by the same token it excludes some obvious other periods, such as a 10 or 20 year cycle. Longer cycles can’t of course be excluded, but are not as probable as a cycle that nearly matches a known solar system cycle.
By the way, how are the Packers and the weather doing in Wisconsin?”
My response:
Bob, thanks for the comment. It’s my understanding that the axis has a number of cycles within it. There is the longer term cycle of 23,000 years where the tilt of the earth traces a complete circle about a vertical line through the earth as one would observe it against the solar plane (or something like that). That means that, every 11,500 years or so, our seasons would be completely flipped on a calendar year basis, which is kind of an interesting thought. I never really considered that before, but I think that means that our seasons will shift by a day every 35 years or so. Depending on the direction of the precession, our seasons have shifted by a week earlier or later from when our country was founded.
Sorry for the random ADD moment.
Anyway, within that cycle, the axis doesn’t trace a perfect circle, but “wobbles” with an axial tilt that ranges from 21.5 degrees to 24.5 degrees. We are currently at 23.5 degrees. A complete cycle here is estimated at 41,000 years.
A third Milankovitch cycle is the elliptical nature of the earth’s orbit, which ranges a smaller degree of elliptical (more circular) to more elliptical in cyucles of 100,000 years.
Then, there is Chandler’s wobble, which is a slight wobble of the axis due to the fact that earth is not a sphere and there are slight changes in the center of gravity. This is 433 days, but it combines with other factors so that a full “wobble” period is about 7 years. It’s myt understanding that this is very slight (around 15 meters).
I’m not familiar with a 180 or 360 year period as it relates to the earth’s axis or precession. Those numbers sound more in line with the cycle of the Sun’s position in the solar system relative to the Center of Mass, which Landscheidt believes is key in understanding the sunspot cycles and potential ramifications to our climate. And of course, we are all familiar with the average cycle of sunspots of 11 years. Most of these cycles aren’t perfectly defined, and it’s likely that they vary directly in relation to the interaction caused by the other cycles.
And then, we have all these different Ocean Cycles to consider, as well.
It’s very intriguing, all these cycles, and I am personally a firm believer that all these things are far and away the primary explanatory vehicle in discussing long-term as well as short-term climate changes on earth. I don’t dismiss some contributory aspect of short-term effects from things such as human activity, but when looked at in relation to everything else, I think it’s really a stretch to give us much credit or blame for much of anything. One may even call it a kind of egoism.
As for the Packers, it’s been a mixed review. There is a lot of expectation here given the talent of the offensive skill position and the early cohesiveness of the 3-4 defense (which we all expected to have more growing pains than there has been so far). But the offensive line is really struggling, which is messing up a lot of what they want to do on offense. I’m not sure if it will get to where it needs to be to compete as we’d like. But they looked better yesterday – admittedly against a subpar Rams team (on the road, though).
Gotta admit, I never expected the Broncos to be 3-0 at this point. Must be a nice surprise.
As for the weather, the entire last month has been our summer. The entire summer looked like a lost cause, but since the end of August, we have had very sweet weather. It finally looks to be coming to an end this week, and the normal fall weather is going to be setting in, but it was nice getting a reprieve from the cold and rainy weather that plagued us through mid-August.
Still looking at the ENSO index and seeing positive anomalies, so I’m hoping all these things I’m hearing of a nasty winter are wrong. My own guess would be average to mild based on the ENSO index. But I’m also being wishful when I focus on that and ignore other predictions/evidence.
Here’s an interesting question on the upcoming Winter weather: Do Oak Trees know something we don’t? I’m talking about Acorns.
A couple years ago, we got hit with our most severe winter in memory, both in terms of bitter cold and snow cover. Our wildlife suffers during these years because they run out of food. A friend of mine – a hunter – commented to me at that time that he could see a harsh winter coming because there were so many acorns on the ground. Puzzled at that, I asked him what that had to do with anything. His point was that nature has a way of taking care of its own, and this was the most acorns he could remember seeing. Plenty of food for the small scavengers to tuck away for a long, cold winter. I was skeptical of this, but I could not argue the fact that his prediction bore itself out. And then again last year there were a lot of acorns and we had the most snowfall on record during the first half of the winter.
Well, this year’s crop of acorns is probably the most I’ve ever seen!
To be fair, I’ve searched around a bit to see if there have been correlation analyses done on this, and the resutls – at best – are mixed. It seems more likely that different Oaks produce in cycles, and it is unclear whether or not those cycles correspond with weather cycles. It is possible that the crops do correlate with the weather in the months leading up to winter, which may in itself be a forecaster for the winter weather.
But it’s fun to speculate, even if there’s nothing to it. Kind of makes me feel like one of those farmers who can tell that it’s about to rain because the dog’s eating grass.
