SC 24

When in some very distant future the sun goes into nova, it will expand in size. Quite what will happen no one knows. One version of events is that the sun’s expansion will “push” the inner planets “out.” Another is that the sun will “engulf” all of the inner planets, out to the Earth’s orbit, so that we will be inside the sun. We have about 5 billion years to make our plans for escape.

All this, of course, is interesting, but what I would underline here is that we already have our being in the solar environment. As the third planet from the surface, we are quite close to this blazing giant with a mass a million times that of our little sphere of rock.

Back in 1963, at the time of President Kennedy’s assassination—and we do remember, if we’re old enough, what we were doing then—I was reading an article in a magazine suggesting that we were (believe it or not) on the edge of a new period of major global cooling. Yes. And that, in turn, got me interested in ice ages. And in turn then—in the solar cycle. It seemed to me that if the earth either heats or cools, the sun must be causing that change.

The sun has cycles of activity, the recurring solar cycle. It is measured by the appearance of sunspots. Their average number per month has been charted carefully since 1749 and they form peaks (lots of spots) and troughs (few or none). Each cycle is measured from trough to trough; cycles average about 11 years. Astronomers began to number them in the eighteenth century. The first sun cycle (SC 1) was the one extending from 1755 to 1766. We are now in SC 24. It began on January 4, 2008, when astronomers noted the appearance of a sunspot, high on the sun, with reversed polarity. Both are necessary to signal the change from cycle to cycle—appearance of a sunspot at high latitudes as well as magnetic reversal. Sunspots are magnetic fields and, like all magnets, have a N-S polarity. The spots of a cycle always have the same alignment. When a spot appears high on the sun with reversed polarity, S-N, that signals the start of a new cycle.

SC 24 is now beginning to peak. Above I show an image from NASA (link) of SC 23 and SC 24, the latter as far as it has gone. In an article that appeared in March 29 (link), NASA predicted that SC 24 will be “weak,” producing about 90 sunspots at its peak, the lowest observed since 1928. This follows SC 23 which had an unusually enduring and inactive trough. What this might mean is that the sun is going into a cooler period—and that, at least based on common-sense logic, should also mean that the Earth will echo that back. Is such speculation heterodox?

Well, let’s just see. Precise measurement of cycles began in 1749, but pretty good measurements go much farther back. And looking back, we see earlier periods of very low solar activity. The most pronounced of these was the Maunder Minimum, a seventy-year period extending from 1645 to 1715. That period was experienced on Earth, and has been referred to since, as the coldest period of the Little Ice Age, which began earlier. Another, later dip, which lasted 40 years, is known as the Dalton Minimum, 1790-1830. Significant global cooling took place then as well. These two minima are named after astronomers, Edward Maunder (1851-1928) and John Dalton (1766-1844). Measurement during the Maunder Minimum, as shown below in little red crosses, was not quite as systematic as it later became, but the extremely low activity of the sun was noted by a handful of expert astronomers at the time, and the Little Ice Age is well documented (see, for instance, The Little Ice Age: How Climate Made History, 1300-1850, by Brian M. Fagan). During the Dalton Minimum, lower-than-average temperatures were noted, and one observatory in Germany, Oberlach Station, observed a 2° C drop in temperature over a twenty-year period. Herewith a look at 400 years of sunspot observations from Wikipedia (link). The colored lines show the sun cycles; the black line is not identified in the source but may be carbon-14 measurements, an indirect indicator of sunspot activity. More on that on Ghulf Genes (link).

The modern scientific consensus rejects the idea that the solar cycle has a direct effect on global temperature. Climate is a massively complex phenomenon, not well understood even today. And the heat-production of the sun at its minimum (in the troughs) is only about 0.1 percent lower then its output at the maximum (in peaks). But then, of course, I wonder why we speak of the Little Ice Age—which had drastic consequences at least as recorded in Europe—and the cooling during the Dalton Minimum. Could the modern consensus have something to do with excessive caution in a day and age when Global Warming is a major socio-political issue? If the experienced global warming is due to what, in the chart above, is labeled the Modern Maximum, i.e., of solar activity, and may be followed by a lessening of solar heat production in due time (a “weak” SC 24 followed by others), let us hope that that period won’t last long either. Cooling periods are much worse for humanity than periodic warmings.

Dust Bowl Remembered

Click to enlarge; Esc returns to post.

We are experiencing a significant drought this year. It prompted me to look back to the Dust Bowl days, 1934 and 1936. The maps above show the conditions that prevailed in July of 1934 and July of 2012. It tells me that conditions in 1934 were a whole lot worse. Agricultural practices put in place after the Dust Bowl days, to prevent future recurrence, were still in the future. The over-farmed regions turned into dust. We were also in the midst of the Great Depression.

The 2012 map, above, is instructive. I learned today that in the nineteenth century people called the region now known as the Great Plains (a map of that is shown as well) “the Great American Desert.” The land in those regions was considered very poor. But it was developed for agriculture nonetheless. On the 2012 map that is the region exhibiting the worst drought. The patterns between the two periods are very similar. The inset image is from Wikipedia’s article on The Great Plains.

No. This is not an attempt to question Global Warming. What the maps reveal is the fundamental geological characteristic of the North American continent. With masses of oil available, much water can be pumped—and poor soil can be made to yield crops by artificial fertilization. Changes in climate, whether temporary or permanent, can test marginal regions to the limit. This is happening now—but that test in 2012 is relatively mild. It was a whole lot worse in 1934.

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: