On Monday, July 4, the Earth will be at its furthest distance from the Sun for 2016, at 152,103,776 kilometers, or almost 95 million miles. Don’t let the numbers make you overconfident; it’s still close enough to get a good sunburn from the Sun’s ultraviolet (UV) radiation.
Although the angle of the Sun in our summer means more when it comes to solar energy than its actual distance, the Sun is actually fundamentally different than it was a few years ago. As I wrote this (last weekend), the Sun was on its third consecutive day without sunspots and the accompanying solar activity that generates, among other things, our Northern Lights. The last few weeks are the quietest the Sun has been since 2010.
This sunspot drop off is nothing to be concerned about; it’s an indication that the Sun is heading for a period called The Solar Minimum.
The Sun, for reasons not fully understood but readily measured, goes through a roughly eleven year cycle with periods of heavy activity (sunspots, storms) and minimal activity (peace and quiet) at each extreme. Astronomers were aware we were in a ‘maximum’, and were waiting for the drop off in activity which shows we’re now heading the other way. The next Solar Minimum is expected to arrive in 2019-2020; between now and then, spotless Suns will be measured in days, and then weeks, and then months.
An example: in 2009, there were 260 days without sunspots, while 2012 through 2015 had sunspots every single day except one.
So, what does it mean to you and I trying to enjoy sunny weekends at the beach or in our back yards? In reality, not much. Local weather will have a far greater effect on your activities than this will. However, the drop in UV radiation will allow our upper atmosphere to cool somewhat, collapsing it a little and allowing cosmic rays from other places in the universe to penetrate. Measurements show levels to already be up 12 percent from last year. The effects of more cosmic rays vary from the interesting, like the formation of more clouds and increased chance of thunderstorms, to a little more scary: increased radiation exposure, especially for passengers on commercial jet liners.
Before you start to panic, keep in mind that we’ve been there many times before; this is an eleven year cycle, after all. Sure, this is guaranteed to generate all sorts of ‘the-sky-is-falling’ predictions, and the global warming crowd will undoubtedly attribute every unpleasant weather event to the Alberta oil patch causing the Solar Minimum. I just thought I’d get in my two cents worth published in that bastion of scientific thought, The News Review, before it hits the tabloids.
Enjoy the cycle. You’ll never notice the difference; just thought you should know.
