Sunday, December 29, 2013

December 29 ABN News

I awoke this morning after a late night chasing the drilling problem in the firn tent, and thought how well I was acclimatizing to the cold. Actually though, it wasn’t me acclimatizing to the weather: just some amazingly warm weather. Our maximum today was -1.5C in the shade. Drilling tent doors were open to try and keep them cool enough to work and the processing tent was not used. Some outdoor shallow coring was done instead, and even this required some care and shading to keep the ice from melting in the sun.

We tried a few things with the firn drilling in order to get it to retrieve core, initially without success, but eventually a combination of things seemed to do the trick, and we were back in action. We had expected a long ‘lock in’ zone (as explained in an earlier post), but we are finding that the pores are closing very fast (with increasing depth) and it is proving difficult to get large air volumes. This is disappointing for the firn air science, as it won't provide as extensive a record as we had hoped. There is a bright side, however as understanding the unexpected properties of this site and the way the snow turns to firn and then ice will be useful in the broader interpretation of ice core results. Such unknowns are part of the territory of course with research.

Tomorrow six of the first half team change out from camp, and six second halfers arrive. Those of us in the firn air team will spend a bit of time hunting for the last dregs of air at depth, and pack up for a return to Casey the day after. It will be a strange feeling to end my personal ABN chapter after nearly two months. Still, I am jumping the gun â€" there will be more to report in the next couple of days, and that is without even considering what the weather might do to plans.