Wednesday, December 26, 2007

How Cold Is The Big Lake?

OK, so it's getting so I do this every year. Last year, on December 26th, and in 2005, on December 13th, I published pictures from NOAA, of the current Lake Michigan surface temps. This winter has been closer to normal, with snow cover since Thanksgiving an ice on the inland lakes for Christmas.

Still, a look at the big lake, our main weather maker, shows that it is warmer each year. This is bad news for lake levels, as a warmer lake loses more water to evaporation. Ideally, we would like to see the big lake freeze over early and keep all of its water for a month or so.

It is easy to look at lake temps and point to global warming, but there is more going on. Zebra mussels have filtered the water to a new clarity, and sunlight is now penetrating Lake Michigan to greater depths than we have ever seen before, changing the physical characteristics of the lake.

We could also consider the sun. We had a sunny day on Christmas, and a sunny dawn today. We have been treated to more of our usual share of sunny days this December, although the sun doesn't rise very high this time of year.

We watched the sun set over frozen Lake Leelanau last night as we exchanged presents at my brother's place. The sun descends at an oblique angle, reflecting back and shining onto the clouds long after it has disappeared beneath the snow and ice. I don't know how you could have a photo of that sort of sunset, as it is really a series of scenes, with new and more improbable colors every time you glance up.

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