Jimmy Westlake's Celestial News column appears monthly in the Steamboat Today.
Find more columns by Westlake here.
Steamboat Springs A year ago, I wrote in this column about the prolonged solar minimum we were in that seemed to have no end. Now, one year later, astronomers still are scratching their heads about the sun's paucity of sunspots. So far this year, according to the NASA Web site www.spaceweather.com, the sun has been spotless for 191 of 243 days. That's 80 percent of the days this year. Furthermore, as of Tuesday, the sun has gone 52 days straight without a single visible sunspot. This ties last year's equally long stretch of spotless days. What's going on with our sun, upon whose energy we depend for life?
No one knows.
The sun's ho-hum routine has been this: about every 11 years, the number of sunspots and other active regions on the sun reaches a fevered pitch, followed by a period of relative calm, as solar magnetic fields get all twisted up and then relax. Like a cosmic heartbeat, this 11-year rise and fall in solar activity has gone on for decades, even centuries, with few significant interruptions. The last solar maximum occurred in 2001 and 2002, when giant sunspots speckled the sun and record-breaking solar flares erupted into space. Clouds of charged particles from the sun generated brilliant displays of the Northern Lights over Colorado and points farther south. Since 2002, solar activity has waned, as expected when nearing the end of an active solar cycle.
The anomaly is that this solar minimum is lasting for an uncomfortably long time with no end in sight. The average solar cycle lasts for 131 months, or about 10.9 years. The current cycle has lasted for 156 months (13 years) and is still counting. Sunspots during the past three years have been scarcer than a hen's teeth, and the few that have appeared have been tiny and short-lived. Every morning, I check out the daily image of the sun on www.spaceweather.com and scan for sunspots, but every day, it's the same story: "The sun is blank today - 0 sunspots." The last time the sunspot cycle went into extended hibernation was during the so-called Maunder Minimum, between the years 1645 and 1715. This period coincided with Europe's "Little Ice Age," one of the most dramatic episodes of global cooling in recorded history. Although the sunspot-climate connection is poorly understood, there is little doubt that it exists. Since 1998, average global temperatures have been falling, not rising, according to an August 2008 Boston Globe editorial. This coincides with a decline in the sun's magnetic field strength, according to an American Geophysical Union report last month. If the sun's magnetic field continues to decline at its present rate, the sunspot cycle would disappear completely in 2015 - a la, Maunder Minimum No. 2. Now, no one is making this prediction yet because no one is sure about the internal workings of the sun or the sunspot-climate connection.
And, isn't that the important point? We aren't sure about any of this computer modeling of the sun's behavior or Earth's changing climate. In spite of our best computer models, the sun is doing its own thing. We have much to learn by just sitting back and watching.
Professor Jimmy Westlake teaches astronomy and physics at Colorado Mountain College's Alpine Campus. He is an avid astronomer whose photographs and articles have been published all around the world. His "Celestial News" column appears weekly in the Steamboat Pilot & Today, and his "Cosmic Moment" radio spots can be heard on local radio station KFMU. Also, check out Jimmy's astrophotography Web site at www.jwestlake.com.