Today is our last trip out on to the ice. WHOI is deploying their last ITP, Dave Meldrum is putting in his third SAMS-IMBS and Alice & Kristina are directing an ice-sampling team. The day starts out warm and sunny (OK, the air temperature is 2C. This is the Arctic after all).
A *warm and sunny* day in the Arctic!
After the ITP hole is drilled, Sarah Zimmermann puts a CTD down the hole to profile the water under the ice. They are interested in the freshwater content of this water. To them, freshwater does not mean "drinking water" but instead water of lower salinity that comes from ice melting.
Sarah Zimmermann drops a CTD sensor into the ITP hole before the ITP is deployed to measure the salinity of the water near the surface under the ice. Photo by Gary Morgan.
It is difficult to sample this surface layer from the ship because the ship is moving around and mixing this water up. One of the results to come out of the multi-year BGE project is that the freshwater layer is increasing in the Beaufort Sea. The cause of this increase is not well-understood.
I have been on the LSSL for 3 weeks. The ship has been moving, breaking ice, rolling with waves and all the while the engines have been running. By stark contrast, the ice is quiet. We are moving -- this floe has drifted over 4 miles since yesterday afternoon -- but the motion is not perceptible. Ice feels firm underfoot, and today there is a crunch of ice and snow. We look ahead of where we walk: low spots, darker ice (where the dark water below is showing through) and melt pond edges are avoided. Attached is an ice safety guide that can give you an idea of how thick ice should be for various activities. As part of the deployment process, holes are drilled in the ice to be sure it is thick enough (see 17 July Journal Deploying an ITP? and 30 July Journal Ice Recon from Helo).
The first thing noticed when stepping on the ice is Q U I E T. Then, we see the shapes.
Here in the Beaufort Sea we are seeing sea ice -- ice that is made from frozen ocean water. We are not seeing icebergs. Icebergs are formed from frozen fresh water and are formed on land. Icebergs are formed when chunks of ice break off form these glaciers and are found in the sea and on land. Attached is more information on icebergs from Environment Canada.
Do *you* see a heart in this ice? Being out on the ice gives us an opportunity to notice fine details in the ice structure that often cannot be appreciated from the ship.
The isolation is dramatic. When I look back at the ship, I think of astronauts looking back at Earth.
Though we are in constant daylight here, the clouds give an appearance of *Northern Lights*
Our helicopter is their LEM.
My Arctic Friends in front of the helicopter. Much like the LEM was the way off the moon for the astronauts, the helicopter is the way back to the ship for us.
As our work ended, the clouds rolled in and the ice camp looked quite desolate from on board.
The last helicopter ride off the ice. The buoys stay behind to collect the data.
The next time we will be off the ship is in Kugluktuk on 21 August.
So long, for now, from the Louis!