Submitted by Anonymous on Sun, 05/27/2007 - 18:05
Forums
Greenland Ice Studies

Ms. Dodds, I have enjoyed reading about your journey and shared the entry about the new food storage facility with a visiting student. Marc asks:what  is the temperature down in the freezer, and what keeps the walls from caving in!My question is about the Uv intensity testing. You stated that sunlight provides the energy for chemical reactions in the snow, but the sunlight doesn't penetrate very deep. Can you explain what this means and the importance to the area?Also, on a recent CNN telecast, it was stated that 100 billion tons of ice per year melts off of Greenland . Is that accurate? Thanks, and stay warm!Lollie, Redd School,Hou Tx.

Mon, 05/28/2007 - 10:13

Jo Dodds

Hi to all at Redd School.The freezer is 9 feet deep and is essentially the temperature of the firn at that depth, approximately -20 to -22C. And since there is movement in the firn and ice, the freezer won't last forever. The old one is four years old. I had the opportunity to go down into the Science Trench which is below the surface, similar to the freezer. Many steps have been added to the entry into the trench as the yearly snow accumulates (approx 60-65 cm per year). Not much is going on there now since the old stairs are angled, the shelving is bowing and the roof support is uncertain.
So many chemcal reactions occur in the first few centimeters of snow, but it does depend on the energy from the sun. Look at my current journal postings (two on May 28) for more information. Plus we are having a webinar on Friday, June 1, with the photochemistry scientists. If you haven't signed up, it isn't too late.
Many of the measurements that the photochemistry scientists do here are also done in populated areas, such as Houston. They can have a better idea of what is happening in the atmosphere by studying the chemicals here is a pristine environment.
The 100 billion tons of ice melting per year may also include calving of the ice at the edges of the ice sheet. I am not sure where they obtained their data, but when I asked your question to one of the scientists here, they seemed to think that was reasonable.
I hoped I answered your questions. Email more!
Jo Dodds