Visualization Vednesdays highlights graphics and movies created by professional scientists and explains the science behind the visual. I’ll be focusing on physical oceanography cause they be my peeps, but if you know of another great ocean visualization please send it my way. But, there are some rules. These videos have to be made by the researchers themselves. No graphics department, just the pure creativity of scientists. Because really, who doesn’t enjoy beautiful things?
There are oodles of movies about the loss of sea ice in the Arctic. But I heart this one because it shows the pathway by which sea ice is leaving the Arctic. As the movie progresses from 1980 to 1995 (I totally admit the data is a little old), we can see really old and thick ice (white regions) leaving the Arctic on the bottom right hand corner of the screen just east of Greenland via a constriction called Fram Strait. The blue regions show younger and thinner ice. The dancing red worms are drifter tracks, which are really just large buoys imbedded in the ice and whose positions are tracked via satellites. And just like the ice, they too are getting the hell out of dodge via the same pathway.
The movie was created by Ignatius Rigor, a sea ice scientist at the University of Washington. It combines sea ice extent from satellites, with sea ice motion and age obtained from the satellite tracked drifters. I personally think the drifters are pretty awesome, not only because I am currently working on a project using the data from these buoys. They are part of a program to track Arctic ice that has been going on since 1979! So long that the buoys dance across the Arctic has changed from disco to moshing to dubstep.
Ice leaving the Arctic isn’t anything new. Transpolar drift has existed for a long time and pushes ice towards Fram Strait and eventually into the North Atlantic, creating various sorts of aquatic hazards for mariners (along with the scores of icebergs that come from Greenland). The problem now is that not enough thick ice is being produced to replenish the ice that drifts out of the Arctic. It is the loss of this old thick ice that worries scientists.
There are two different categories of ice that scientists like to talk about: first year ice and multiyear ice. Or as I like to call them, baby and grandpappy ice. First year ice is the baby of the Arctic, having just been created when it gets cold, dark and stormy in Autumn. Baby ice proliferates, covering not only the entire Arctic but more southern basins such as Baffin Bay (between Greenland and Canada) and the Bering Sea (between Alaska and Russia). Baby ice’s other name is seasonal ice. It forms every year, but a large part will melt in the spring and summer when the sun and warmth return. Only in the Arctic Ocean, usually far from the coasts, will baby ice survive the summer and become thick, old grandpappy ice, the multiyear ice we care about.
When it’s there, sea ice protects the interior of the Arctic Ocean. It insulates against the effects of surface heating, giant Arctic storms and even precipitation. It is an excellent platform for polar bears and walruses to have polar parties on. There are even entire microbial communities within brine channels in sea ice! In the movie above, we can clearly see there is less and less multiyear ice in the Arctic. This means that less of the Arctic will be ice covered in the summer, since ice that could have hung around all summer long is being flushed out to the North Atlantic. It’s a little unclear what the effect of less multiyear ice will be, but we do know it will change seasonal and long term patterns in the Arctic. Whether these are good and bad we will eventually find out.