Low sunspot activity puzzling to scientists

Has the sun been feeling a little less hot lately? It might seem odd to ask that during what is usually the hottest part of the year. But the brightness of the sun is actually affected by things called sunspots – and they have been noticeably absent this year.

Sunspots, dark spots on the sun which can span as much as 50,000 miles in diameter, are caused by magnetic storms. The spots indicate areas of increased magnetic activity, which are commonly accompanied by solar flares. These flares can impact us on Earth by disrupting communications equipment and electrical power grids. They are responsible for the spectacular bright auroras which can sometimes be seen across the Inland Northwest nighttime sky.

But changes in solar activity may also have an impact on climate. Though it may sound counterintuitive, the brightness of the sun actually increases (by about 0.1 percent) with increased sunspot activity. That may not sound like a large amount, but when you consider that the quantity of energy emitted from the sun’s surface is approximately 63 million watts per square meter, a small percentage of that is still a big number.

What is really interesting about sunspots is that they seem to run on a see-saw cycle of 11 years, a cycle which has been documented and studied since the 1800s. Activity peaks in the middle of that 11-year cycle, which was back in 2001. Scientists expected a new cycle to start this year, with sunspot activity peaking again sometime in 2012, but so far nothing is happening.

The sun is as inactive as it was two years ago, and solar physicists don’t have an explanation why. There have been periods in past history where the level of sunspot activity was unusually low. The most extreme case occurred during what’s known as the “Maunder minimum”. This was a period from about 1645 to 1715, which happened to coincide with the Little Ice Age during which much of the world was subjected to bitterly cold winters. Of course there is plenty of ongoing debate about how much influence sunspot activity has on global climate.

August is the peak month for “fire weather” across Eastern Washington and North Idaho. Dry lightning has been a threat over the last couple of days. Though temperatures have cooled from the middle and upper 90s we saw this past Wednesday, it looks as if a ridge of high pressure will once again build over the Northwest for the upcoming week. This will bring us more hot and dry weather. The high heat and general lack of moisture will result in abundant dry vegetation across the area. Any subsequent “cold fronts,” with their potential for dry lightning storms and gusty winds will be bad news for the region.

I wanted to mention that this is the 100th weather column that I have written for The Spokesman-Review. My columns have appeared in Idaho’s Handle Extra since Fall of 2006 and most recently have also been included in Spokane’s Valley Voice. I hope you find the information interesting and educational. If there are any topics you would like to see covered, e-mail me at weatherboss@comcast.net.