Will Sun Spots Heat Up an Already Hot Earth?
News from NASA this week brings up an interesting issue in solar science and a possible problem for those of us feeling the heat on Earth. It seems that the current solar minimum may be coming to an end, and the next Solar Cycle is just beginning, on its way to a solar maximum. Minimal sun spot activity has been correlated to cooler temperatures on Earth, which presently would be a nice relief from the increased temperatures we have been seeing as of late, but unfortunately, even during the last minimum, we saw very little relief in terms of degrees, which doesn’t bode that well for the now just-beginning solar maximum.
Nov. 7, 2008: After two-plus years of few sunspots, even fewer solar flares, and a generally eerie calm, the sun is finally showing signs of life.
“I think solar minimum is behind us,” says sunspot forecaster David Hathaway of the NASA Marshall Space Flight Center.
His statement is prompted by an October flurry of sunspots. “Last month we counted five sunspot groups,” he says. That may not sound like much, but in a year with record-low numbers of sunspots and long stretches of utter spotlessness, five is significant. “This represents a real increase in solar activity.”
A close-up of one of the October 2008 sun spots, taken by Alan Friedman.
Ok, so minimums and maximums aside, what do sun spots have to do with the Earth and its neighbors?
Sun spots appear when the Sun’s magnetic field becomes tangled on itself, during the Sun’s rather turbulent rotation of the gaseous surface, and when the magnetic field becomes tangled, it can poke through the surface gases, exposing the darker core of the Sun. The Sun’s equatorial region “rotates” faster than the poles, so sun spots usually appear around the Sun’s equator, as this is the region which exhibits the most turbulent activity of the magnetic fields. Oh, and if that weren’t chaotic enough, the poles then reverse themselves, corresponding it seems to the solar maximums.
The Sun spots produce extra ultraviolet light as well as x-ray radiation, which finds its way to Earth. The extra UV and X-ray radiation causes the Earth to heat up, and the heat causes the atmosphere to expand. Hmm, I wonder if the atmosphere expands, if that won’t allow more room for all that extra carbon we keep pumping into it? Doesn’t matter, as the UV and X-rays also creates more ozone in the upper atmosphere, which we all know traps more heat in the atmosphere.
An image of the Sun’s x-ray radiation.
Sooo, if there are more sun spots, does that mean that the Sun will be hotter? Sun spots cool the Sun’s surface, but really have no net effect on the gazillion degrees that the Sun is. But increased numbers of sun spots may heat up the Earth. Not so good news, eh? The last maximum was around 2000, and that year is among the hottest on record, and guess what, even with the minimum lately, the years are still getting hotter, so who knows how hot things will get when the Sun starts spotting up?
The Japanese have a probe orbiting the Earth right now that is focused on the Sun (the image at left was taken by the Hinode probe). The probe is studying sun flares, related to sun spots. NASA also has the Stereo mission that is studying coronal mass ejections and creating 3D images of the Sun. Not that these missions will shed light on how hot the Earth can get from sun spots, but it is a good start in studying the most important body in our Solar System.
On the opposite side of that coin, the period between 1645 and 1715, known as the Little Ice Age, was an extended period of low sun spot activity. Maybe if we can figure out how to discourage sun spots, we can in effect cool our planet? Just an idea.
NASA, sun spots, sun, solar minimum, solar maximum, global warming, increased temperatures, UV, X-ray, radiation, solar flares, coronal mass ejections, Japan, Hinode, Stereo mission, magnetic fields, Little Ice Age
