wmartin@brl-tgr.ARPA (Will Martin ) (05/23/85)
Those of us using the shortwave (HF) spectrum over the past few years have seen the solar flux decline and propagation conditions worsen as a result. Some comments in discussions of the sunspot cycle have mentioned fears that this low level is not just the normal trough of an eleven-year cycle, but the beginnings of a longer period of abnormally-low sunspot levels, with concomitant ill effects on our ionosphere. I know there have historically been periods of low sunspots and these have had effects on earth. What is the current astronomical thinking about this prospect? Is it likely that we are entering into an extended period of low sunspot or solar flux numbers? If so, what is predicted for the extent and severity of this decrease? (Or is it unpredictable?) Or is it just a supposition that this is happening, and the odds are in favor of this being just the trough of a regular 11-year cycle, soon to move back up to levels considered "normal" over the observational history? This has immediate economic consequences, in addition to the scientific interest. The glaciers might return, which would lower some property values and raise others. (:-) Also, if shortwave propagation is to continue to be as lousy as it has been recently, there is no reason to sink money into fancy and expensive radios, and we might as well wait for the turn of the century and see what technological marvels have been developed, instead of buying some now and watching them become obsolete while we get minimal usage from them... So, astronomers and solar physicists, what is the answer? What is going to happen on the sun in the next 20 or so years? Regards, Will Martin USENET: seismo!brl-bmd!wmartin or ARPA/MILNET: wmartin@almsa-1.ARPA
stephany.WBST@Xerox.ARPA (05/24/85)
Re: Sunspots in next 20 years The Mauder minimum was a period without any sunspots for a period of about 60 years to the point where scientists doubted that they ever existed. During this time the earth experienced the "little ice age". Look at those old book with the people clothed from head to foot in Dickens and others. Remember that picture of Dante with only his face sticking out from a mass of clothes, and that was in "sunny" Italy. The Black Death was not due to plague virus but due to the drop, by an estimated factor of 1/2, in the world's food supply due to the lack of solar activity. The Worlds temperature has been rising since this period where it reached a peak in 1945, then began to decrease, and by 1960 the growing season was shortened by 2 weeks in England. In the last 10 years the temperature has swung up again, probably mainly due to the extremely high sunspot activity, not the greenhouse effect with CO2 produced by man. Most of the world's CO2 is produced by termites digesting wood and by Ocean plankton, not by man. We have been seeing the highest solar activity in recorded history, with the peak sunspot count exceeding 200 for the first few times. A decrease is very likely, not to a low but to a more "average" condition. In otherwords we are accustommed to an excessively high sunspot count and are somewhat spoiled by it. Sudden cut offs of solar activity are unlikely, the usual condition being that the peaks die out over a period of many decades. So in all likelyhood the next peak will be similar to the last but probably may not break 200, although every other peak tends to be somewhat higher and wouldn tend to make this coming one bigger. I would not let this stop me from buying new equipment. Even during sunspot minimums DX is good even if it is not spectacular, but you have to shift to the Lower bands. But remember, in 1974, at almost the minimum, there was a solar flare that gave us the same conditions as were in effect during the 1969 peak for 2 weeks. Even without the flare you could work DX and make many contacts by selecting the right band at the right time. The guy that waits for a solar peak for his DX is missing all the challenge. As far as world wide climatic conditions, the only thing that bothers me is that there is an Ice Age every 25000 years. We have 10,000 years of no ice. The last ice age ended 12000 years ago (10,000BC), and we are 2000 years overdue for another one. As far as the ice coming gradually, it does not. Mammoths found in Siberia, frozen in the Ice, had buttercups in their stomachs. What happened so that a mammoth that was eating Buttercups was frozen in ice before the Buttercups digested and remained frozen for over 15000 years? But I would not let this stop me from buying a house. I hope that answers some of your Questions. Joe N2XS (spark forever)
jhs%Mitre-Bedford@d3unix.UUCP (05/24/85)
Speaking of reduced Solar activity, whatever happened to the reports I remember hearing in the eary Seventies that the Sun's thermonuclear reaction had ceased? Specifically, in the early Seventies, I read about some experiments that dealt with measuring neutrino flux from the Sun. As I recall, neutrino flux had been predicted theoretically and measured in the Fifties or so. Then somebody revised the theory and found that the actual flux should be a factor of two different from what they had thought earlier. So some universities set out to make some new measurements with higher precision, to see if the new theory was borne out by careful measurements. The new setup showed: ZERO neoutrino flux. They assumed that the instrumentation was malfunctioning and checked it all out. It was NOT malfunctioning. It still showed ZERO neutrino flux. According to the theory, if there were a thermonuclear reaction going on in the Sun, this would generate a measureable neutrino flux. In the absence of such a flux, it was concluded that there COULD NOT then be a thermonuclear reaction in the Sun. Since earlier measurements HAD shown the predicted neutrino flux, it was concluded that there HAD BEEN thermonuclear activity in the Sun in the Fifties, but that in the Seventies it had ceased. As I recall, the articles at that time went on to speculate whether it was a permanent change or just a cycle of periodic activity in the Sun. Does anybody remember these articles? Does anybody know how this disturbing matter was finally interpreted? Assuming that the Sun's thermonuclear power source is now defunct, how long would it take for things to get unpleasantly cool out our way? NOTE: I believe I can locate a copy of at least one article on this subject from the early Seventies, if anybody cares. 73, John Sangster, W3IKG
jhs%Mitre-Bedford@d3unix.UUCP (05/25/85)
Re: DXing during periods of low Solar flux. Gee, guys, all we have to do is have even a SMALL nuclear war once in a while and the ionization will go back up and give us some real nice band openings at VHF followed by several good days of DXing on 10, 15 and 20. (Not to mention the WARC bands.) Ya just gotta think positive, is all. -John, W3IKG