On Wed., March 25, two Dartmouth researchers came to LHS from third until fifth period to talk about their latest project, the Ice-MITT, and their recent trip to Barrow, Alaska.
Dr. Rachel Obbard, a professor at the Thayer School of Engineering, and one of her undergraduate students, Ellyn Golden, explained the significance of their research on sea ice to science classes ranging from biology to physics. Sea ice, a bumpy, permeable ice, has interesting characteristics that draw in researchers.
“[We set this up] through [my] connections in Polar TREC, that was the group I went to greenland with,” said physics teacher Mr. Mark Buesing. “The polar science community is pretty small. They sent out an email, [we accepted it.]”
Fresh water freezes, creating pockets of salt water, which are referred to as brines. It is these brines that make the ice worth researching. The brines create an almost sponge-like appearance in the ice.
One of the most interesting characteristics of sea ice is the fact that the two ends of the ice are different temperatures. The side that is closer to water is the “warmer side” (typically around 28.4°F) while the side exposed to the air is the cold side (air temperature in February is -4°F, at the warmest). The Ice-MITT is a special container that the researchers developed to keep the ice cold. Understanding the temperature difference between the ice is an essential part of this process.
The research of the sea ice can help in a multitude of ways. In terms of biology, the ice creates a thriving ecosystem. Plankton and algae breed in the cracks in the bottom of the ice, which, in turn, is eaten by fish. Bigger fish eat those fish and so on down the food chain.
The sea ice also holds cultural significance. If the ice melts, the hunting grounds for the area natives will be gone, so whale and polar bear hunting will cease.
Understanding what helps preserve the ice can help the fight against global warming as well. Sea ice provides a protective layer from the sun, preventing the rays from being absorbed by the earth. When the rays are absorbed, the temperature of the earth rises.
“Scientists are trying to model climate and the climate is changing the fastest in the polar regions,” Mr. Mark explained. “Earth science people are trying to model what is going on in the poles. In order to do that more precisely, make a model that is more accurate, they want to know what are the thermodynamic properties of this ice.”
