Thursday, June 30, 2011

Looking at Sunspots

Long before climate change became a catch-phrase, I got interested in sunspot activity. Back then (around about Kennedy’s assassination), my interest was triggered by understanding ice ages. It struck me then that the most plausible, indeed the sort of obvious, explanation of these strange periods had to have something to do with solar activity—rather than sudden shifts of the earth’s upper crust or tectonic plates sliding to the wrong or right places on the planet. Hence my interest in the sun—revisited time and again on the old LaMarotte and also, once, on this new edition.

Today I happened across a reference to raw data on sunspots on this NASA site. It points at this file; it holds averaged sunspot counts per month from 1749 through May 2011. I find such data irresistible; soon I had the values formatted well enough for uploading into Excel. Here, then is a graphic that shows 262 years of sunspot activity, plus five additional months for this year.

Fascinating image—the sun’s cardiogram, you might say. After staring at it for a minute or two and noting that, perhaps, the trend was up, I asked Excel to insert the trend line of these data; it is shown in red. Yes. An upward trend based on 2,887 data points. Just for the fun of it, I also plotted two subsets of these data, each for 20 years, one for the beginning and the other for the end of the period shown above. Those graphics follow, done to the same scale as the first image:

Interesting again. In the last half of the eighteenth century, all three peaks are lower than the two shown for the 1989-2011 period. Right now, to be sure, we are at the beginning of a build-up to a peak that won’t arrive until about the middle of 2014—a peak projected by NASA to be much lower than the last one in 2001.

I love these long, long data sets. They are much more reliable than the Here, Now, Today. In 2007 and 2008, for instance, we’ve had record (2008) and near-record (2007) quiet solar years; and the next peak will also be low. Will it be followed by another deep, wide trough in the 2020s? We don’t know for sure. Is climate change sun-caused of man-caused? If the former, do recent events portend a change in trend? Wait another two-and-a-half centuries to pronounce on that probability. Boy are we little—and is our life short—in contrast to that blaze in the sky that gives it to us—life, that is.

The projections I mention are also from NASA, here:

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