Although the world apparently did not end on Dec 21, 2012 the date triggers strong feelings for most Alaskans every year. Of course it is because it marks the winter solstice…the shortest day of the year…and the promise of longer days ahead. It’s a few weeks past the solstice before most Alaskans notice any change, and even longer for the increasing solar radiation to have any noticeable effect on the weather. So, congratulations, we’re about at that point, and in my psychological bag of tricks for keeping upbeat through the Alaskan winter, it is the point beyond which things have got to just keep getting better. My advice is to get outside as much as possible and ingest some of the increasing daylight. At this point in the cycle (January 12th) here are the daylight stats:
|city||day length (hr:min)||daily change (hr:min)|
Notice how the more northerly cities are compensated for the shorter days by the faster return of the light (the light-starved folks in Barrow aren’t scheduled to see the sun for another 10 days, at which point they will go from zero to 44 minutes that first day, then gain 28 minutes the next day, with progressively smaller gains after that–the opposite trend of places south of the Arctic Circle.) [If you are as fascinated about the sun-earth geometry as I am, you might want to check out the SunFinder graph I made a few years ago. Something different in this day of websites and handheld apps: a paper chart that reveals patterns and teaches principles the former can’t.]
News about the sun
Sunrise…sunset, sunrise…sunset… the epitome of constancy and reliability. But despite the repetitive and predictable nature of the sun’s movements (relative to Earth) from year to year, the sun itself is not unchanging. In fact, the latest trends and understandings about the sun are quite intriguing. First off, for those interested in looking for the aurora borealis, signs are hopeful for a big uptick in solar activity, which has been relatively low for a long time. A large and active group of sunspots has appeared on the sun, and as the sun rotates, will be on the earth-facing side soon, increasing the odds of solar flares that might impact the Earth. See http://www.spaceweather.com/ for more info.
This is significant now because as solar activity waxes and wanes over an 11-year tide-like cycle, the length and strength of these cycles changes on even longer time scales. The reasons and consequences of these changes are subject of many theories, but little demonstrable understanding. But they could be very important to our understanding of the climate. In the current situation, despite the current uptick, solar activity has apparently reached its peak and is dropping off toward the next minimum. The peak arrived earlier and at a lower level than what was forecast by NOAA’s space weather folks. This is strongly suggestive that the sun is dropping into a prolonged era of reduced activity. The following graphs tell the story much better than I can:
This graph shows monthly sunspot numbers since the year 2000. The sinusoidal pattern is evident, but with plenty of noise. The red line going into the future is the forecast, made well before the latest peak, which predicted the peak occurring around May 2013. It is looking clearer that the peak is behind us and was about 25% lower than forecast. For a longer view, here’s the sunspot graph (from NASA’s Marshall Space Flight Center) going back to Galileo’s day, when his new telescope enabled the discovery and recording of sunspots:
In your mind you can paste on the latest data from the first graph to the end of this one and see the trend of all the sunspots ever seen by humans. Two facts bear continued investigation: 1) the area mostly void of sunspots labeled Maunder Minimum and the weaker Dalton Minimum of the early 1800s coincide quite well with the Little Ice Age, a cold period experienced in at least the Northern Hemisphere if not globally. 2) The last couple cycles on the chart are eerily similar to the last couple cycles before both of these minima on the chart. Again, I’m not drawing any hard, fast conclusions here, but putting forth some possibilities to consider. This fits in with the other big solar news: the increasing acceptance by scientists of solar-climate connections once trumpeted only by a minority. A recent article by NASA summarizes information presented at a 2011 workshop on solar-climate connections by a large number of top researchers, and although the NASA reporting seems full of caveats not to turn from the orthodoxy that global temperatures are currently influenced more by man-made greenhouse gas emissions and less by natural factors (such as the sun), the underlying research may have more of a turning effect on the debate. The observed slowing/possibly stopping of the global warming trend gives a good reason to look again at the solar connections. [There is more on these topics, with lots of graphics, in a 2-page spread in my 2013 Alaska Weather Calendar, which is now on 1/2 off sale.]
I’d like to hear what’s in your psychological bag of tricks for staying healthy and happy through the winter, or your thoughts on solar cycles, auroras, climate connections, etc.