For the last few weeks I’ve been studying and preparing for my Preliminary Exam, so I’m spending all of my time thinking about clouds and climate. Which, really, isn’t such a bad way to spend time. It’s also springtime in Colorado, so the weekends have been snowy and cold.
While we’re shivering in the mountains, the rest of the climate is going through the typical spring seasonal shift. The sun has risen over one pole and set over the other. The northern hemispheric land masses are beginning their seasonal carbon sequestration. And climatologists are starting to look at changes in sea ice cover.
Two interesting articles went by this week, one from each pole.
In the north, groups studying arctic ice coverage announced that the 2008-2009 winter saw the fifth lowest maximum ice extent since monitoring began in 1979. They also mention that seasonal ice, the sea ice which melts and refreezes each winter, is up from ~50% of all northern sea ice to about 70%.
When I was flying home from Israel last January, we flew into the polar night over Greenland. When the plane flew back into the light of day, we watched the sun “rise” over the arctic sea ice north of Canada. I had the rare opportunity to see the glowing pink light illuminate the beautiful crystalline world below, without any clouds blocking the view. I was surprised to see that the sea ice was not just a blank, white, plain of emptyness, but, even in the depth of winter, it was a patchwork of peaks and valleys, with what looked like ice-rivers flowing around millions of big and little chunks of ice. It really is amazing how dynamic the polar oceans are, even in the deepest freeze.
In the southern hemisphere, the sun set a few weeks ago, and the summer melt season is ending. Satellite groups are reporting on the danger of a possible “imminent breakup” of the rest of a large ice shelf in Antarctica. The pictures (shown above) are really beautiful, and wild. This shelf already lost more than 650 square miles of ice to break-up and calving in the last year (old story with great pics here, new CNN report here). There’s a great and very interesting discussion on the ice shelf over at RealClimate.Org. If you have questions, I can try to answer them, but the ice dynamicists are all over at RealClimate. I highly recommend checking out that site.
According to CNN, the Wilkins Ice Shelf is (or was) about the size of Connecticut. And the largest ice shelf to be threatened so far, that we are aware of.