Thursday, March 26, 2009

Out on the Sea Ice

Last night I had the opportunity to go out on the sea ice with a group of researchers from Environment Canada. They have some instrumentation set up at the edge of a refrozen lead, measuring things like mercury and halogens, which relate to ground level ozone depletion events being studied during this OASIS field campaign (all very fascinating to the atmopsheric chemistry type like me). In case you are wondering, a lead is an area of the sea ice that opens up to expose the water ... these are certainly not permanent and can close up, refreeze, or get bigger depending on the winds and ocean currents. This trip to the ice was mainly to check on the status of the instruments and to do some snow sampling.

The trip out is done on a snowmachine (snowmobile to those of you down south, or ski-doo to you Canadians) over a pretty bumpy trail that was "hand carved" through the ice with ice axes. You may envision the frozen ocean as a nice flat sheet of ice, but in fact it is quite the opposite. As the sheets of ice move and bump into each other, big piles of ice form, several stories tall in some places. It really is quite a sight. Here are a few pics:

A gorgeous sunset on the Arctic Ocean ...

A view of the "rubble ice", caused by ice sheets driving in to each other, raising up the ice in big chunks, some the size of a tractor trailer ...

Me (on left) helping Sandy Steffen (Environment Canada) sample frost flowers. This was how I justified my presence on the trip. :) This flat area of ice where we are at is a refrozen lead. The ice here is about 40 cm thick, or about 16 inches thick. It doesn't sound like a lot, but 16 inches of ice can hold a LOT of weight (you could pretty safely drive a tractor trailer over ice just a few inches thick).

Me about halfway up the climb on the rubble ice ...


As I write this blog entry, the Environment Canada team is racing out to their site to bring in their equipment. The winds are shifting and the area we were at last night will probably be a new pile of rubble ice soon, or may break off entirely from the ice closer to land and drift away ... the ice sheets are moving and it would not be in the best interest of the equipment to leave it out there to either be crushed, or fall in the ocean.

3 comments:

cammyeg said...

Is there a way to predict how the ice will move? I've been watching a site that has a radar of the land ice. It also shows the drifting ice farther out. I've noticed that the land fast ice changes, gets bigger, breaks off, changes. How can you safely go out on the ice with all these changes?

Dr G said...

Use of satellite images and knowing the meteorology helps a lot. What amazes me most though is the local knowledge amassed through generations of living in the area. We have native "guides" that go out on the ice with us and it is amazing how well they can "read" the ice. They can look at how the clouds above the water look, the way the wind is shifting, the way the ice is cracking in certain places, and using all their experience and knowledge do a darn good job of predicting just what will happen out on the ice. It really puts our scientific expertise to shame!

cammyeg said...

Do they see a big difference in the ice? I've read up on the polar bear struggles with regard to hunting and the ice shrinking to a point that the bears numbers are dangerously low. Do the native hunters feel the ice or lack of ice is effecting their way of life?