Blog Archive

Tuesday, March 20, 2012

"Regions of rapid sea ice change: An inter-hemispheric seasonal comparison" by Sharon Stammerjohn et al. GRL 39 (2012); doi: 10.1029/2012GL050874

Geophysical Research Letters, 39 (2012) L06501; doi: 10.1029/2012GL050874

Regions of rapid sea ice change: An inter-hemispheric seasonal comparison

Sharon Stammerjohn (Ocean Sciences Department, University of California, Santa Cruz, CA, and Institute of Arctic and Alpine Studies, University of Colorado at Boulder, Boulder, CO, USA), Robert Massom (Australian Antarctic Division, Channel Highway, Kingston, Tasmania, and Antarctic Climate and Ecosystems Cooperative Research Centre, University of Tasmania, Hobart, Tasmania, Australia), David Rind (NASA Goddard Institute for Space Studies, New York, NY, USA) and Douglas Martinson (Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA)


This bi-polar analysis resolves ice edge changes on space/time scales relevant for investigating seasonal ice-ocean feedbacks and focuses on spatio-temporal changes in the timing of annual sea ice retreat and advance over 1979/80 to 2010/11. Where Arctic sea ice decrease is fastest, the sea ice retreat is now nearly 2 months earlier and subsequent advance more than 1 month later (compared to 1979/80), resulting in a 3-month longer summer ice-free season. In the Antarctic Peninsula and Bellingshausen Sea region, sea ice retreat is more than 1 month earlier and advance 2 months later, resulting in a more than 3-month longer summer ice-free season. In contrast, in the western Ross Sea (Antarctica) region, sea ice retreat and advance are more than 1 month later and earlier respectively, resulting in a more than 2 month shorter summer ice-free season. Regardless of trend magnitude or direction, and at latitudes mostly poleward of 70° (N/S), there is strong correspondence between anomalies in the timings of sea ice retreat and subsequent advance, but little correspondence between advance and subsequent retreat. These results support a strong ocean thermal feedback in autumn in response to changes in spring sea ice retreat. Further, model calculations suggest different net ocean heat changes in the Arctic versus Antarctic where autumn sea ice advance is 1 versus 2 months later. Ocean-atmosphere changes, particularly in boreal spring and austral autumn (i.e., during ∼March-May), are discussed and compared, as well as possible inter-hemispheric climate connections.

Received 20 January 2012; accepted 17 February 2012; published 16 March 2012.

No comments: