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Oden Antarctic Expedition 2010

Hi Anne Marie! Merry Christmas, Happy New Year, and happy Santa Lucia Day! I enjoyed reading your Santa Lucia blog and thought it was so cool that your are part Swedish! What a wonderful memory to make :)

Looks like you're getting a real work out on the ice-you go girl!!! Can you explain what information the Lidar will give the ice team? And how long will it be on the ice? I think I might have missed the explanation. So in general, has the ice pack been more or less extensive than in years past at this point?

Wonderful penguin pics- but then, I've never seen a bad one, they're so photogenic :D Take care of yourself- don't let those 24 hrs of sunshine fool you! Cheers, Lollie

Wed, 01/05/2011 - 14:50

Anne Marie Wotkyns

Hi Lollie - Santa Lucia was fun, as were all the Christmas festivities. The next journal be about our Christmas Eve here on board.The LiDar is a camera/computer system with two types of reflectors (8 total) placed on the ice. The camera scans the scene, uses the reflectors as reference points and takes multiple pictures. Then we move the camera to a new location within the study site, carefully turn the reflectors(on a rotating base) to face the new camera location, then scan again. The challenging aspects are the reflectors (on large surveyor tripods) cannot move(side to side or up/down) at all or the camera cannot accurately merge the scans together for a 3-D picture. We place each tripod leg on a price of wood dug down into the snow, to the ice if possible, so it doesn't shift if the snow melts. We have to bring our a generator to run the computer/camera. It takes about 45 minutes for 2 of us to set up the tripods and 2 to set the camera. Then it takes about 45-60 min. per scan, then we move the camera, turn the reflectors (which are about 100-200 meters apart) and scan again. Yesterday we did the whole process with 7 scans. It took from 10:30 am to 9:30 pm, with breaks for lunch, coffee, and dinner. Then we brought everything back onto the ship. Now Blake will merge all the scans and have a 3D computer picture of an area of up to 2 km from the center of the scan area. The resolution accuracy at 100 meters will be 10 centimeters or better.
The LiDAR gives the sea ice team an accurate, 3D model of the sea ice surface (topography and elevation above sea level). Together with our EM measurements for ice thickness and our snow depth measurements (literally ruler stick measurements) we will ultimately build an accurate physical model of the sea ice to compare with and validate satellite measurements.
As far as what's happening with sea ice extent in recent years, Antarctic sea ice extent has actually increased slightly as a whole in the past couple decades. Although in the Antarctic peninsula area it has decreased dramatically with much higher atmospheric temperatures. The greatest regional increase in temps globally has been in the peninsula area. So the big question is why sea ice has increased (at least in extent - thickness unknown) in certain sectors of the continent.
Anne Marie and Blake