From Dr. Roger Pielke Senior, one more paper saying what we’ve been reporting on since 2007 – Arctic sea ice extent is a significant function of wind and currents, not just temperature.
In 2007, when I was but a wee blogger, I wrote:
A science blogger named Tamino, in a post he made here, challenged me to “explain it or shut up” related to the loss of northern hemisphere Arctic ice this season which he claimed was …” undeniable, that it’s not natural variation” in contrast to the southern hemisphere Antarctic setting a new record for ice extent. While I suspect that sea ice is not his specialty, nor is it mine, I will bring some things to the attention of my readers available from literature.
Just last Monday, NASA was quietly issuing a press release explaining why Arctic sea ice loss was so great this year. (h/t Douglas Hoyt).
Full story: Arctic Sea ice loss – “it’s the wind” says NASA
In fact, in 2009, in further factual explanation for Tamino’s demand that I “explain it or shut up”, I did another post that showed a movie of wind pushing the ice out of the Arctic. See Watching the 2007 historic low sea ice flow out of the Arctic Sea What is interesting about this video is that you can watch sea ice being flushed out of the Arctic sea and pushed along Greenland’s east coast, where it then finds its way into warmer waters and melts.
Fast forward to today, now we have a peer reviewed paper on the issue. And, guess what, in this new paper they quantify it with a nice graph. It seems wind driven export of sea ice has been on the rise.
Dr. Roger Pielke Sr. writes:
New Paper “Recent Wind Driven High Sea Ice Export In The Fram Strait Contributes To Arctic Sea Ice Decline” By Smedsrud Et Al 2011
In response to the post
Peter Williamson alerted us to a related paper that highlights the major role of regional circulation patterns on climate (this time for the Arctic). The paper is
Smedsrud, L. H., Sirevaag, A., Kloster, K., Sorteberg, A., and Sandven, S.: Recent wind driven high sea ice export in the Fram Strait contributes to Arctic sea ice decline, The Cryosphere Discuss., 5, 1311-1334, doi:10.5194/tcd-5-1311-2011, 2011
Arctic sea ice area decrease has been visible for two decades, and continues at a steady rate. Apart from melting, the southward drift through Fram Strait is the main loss. We present high resolution sea ice drift across 79° N from 2004 to 2010. The ice drift is based on radar satellite data and correspond well with variability in local geostrophic wind. The underlying current contributes with a constant southward speed close to 5 cm s−1, and drives about 33 % of the ice export. We use geostrophic winds derived from reanalysis data to calculate the Fram Strait ice area export back to 1957, finding that the sea ice area export recently is about 25 % larger than during the 1960′s. The increase in ice export occurred mostly during winter and is directly connected to higher southward ice drift velocities, due to stronger geostrophic winds. The increase in ice drift is large enough to counteract a decrease in ice concentration of the exported sea ice. Using storm tracking we link changes in geostrophic winds to more intense Nordic Sea low pressure systems. Annual sea ice export likely has a significant influence on the summer sea ice variability and we find low values in the 60′s, the late 80′s and 90′s, and particularly high values during 2005–2008. The study highlight the possible role of variability in ice export as an explanatory factor for understanding the dramatic loss of Arctic sea ice the last decades.
The full paper is open access, and available here (PDF)