Comparison of the sea cover properties in eastern Canadian Beaufort Sea as observed with helicopter-borne sensors in April 2004 and April 2008.
Abstract
During April 2004 and April 2008, ice property data were collected by helicopter-borne sensors and satellite- tracked ice beacons. Ice property data was collected along helicopter flight paths over the land-fast ice and over the mobile pack ice in the eastern Canadian Beaufort Sea (Amunsden Gulf) using an Canadian Ice breaker over-wintering in the Arctic pack ice as a logistic base. Ice thickness, surface roughness data were collected with an Electromagnetic-Laser system and lead/floe distributions with a Video-Laser system. The data is used to validate algorithms to identify ice properties seen as ice signatures in SAR satellite imagery. September Arctic sea ice extent shows that 2004 and 2007 were respectively the start and the continuation of the rapid decline of ice extent within the Arctic. The April sea ice properties reflect this change in the Amunsden Gulf. The land-fast ice extent and thickness were less, mobile ice were thinner and the thin ice extent (0-20cm thick ice) rarely present in 2004 were extensively found in 2008 with areas of up to 50km in width. The 2008 pack ice (lower ice extent) was more mobile under the wind forcing. An thin (60cm thick) flaw lead 20km wide and 200km long was ridged into a 2km wide 10m rubble field and then open up again to 20km providing additional salt rejection to the ocean by renewed thin ice growth even though the air temperatures were below normal. So does the lower ice extent and more mobile first year ice conditions lead to a tempo rarely increase in first year ice ridging and ice volume (and salt rejection to the ocean).
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2008
- Bibcode:
- 2008AGUFMOS11D1147P
- Keywords:
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- 0726 Ice sheets;
- 0750 Sea ice (4540);
- 4540 Ice mechanics and air/sea/ice exchange processes (0700;
- 0750;
- 0752;
- 0754)