R. Kwok et al., J. Geophys. Res., 114 (2009): Thinning and volume loss of the Arctic Ocean sea ice cover: 2003–2008

Journal of Geophysical Research - Oceans, 114 (2009) C07005; doi: 10.1029/2009JC005312.

Thinning and volume loss of the Arctic Ocean sea ice cover: 2003–2008

Thinning and volume loss of the Arctic Ocean sea ice cover: 2003–2008

R. Kwok, G. F. Cunningham (Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, U.S.A.), M. Wensnahan (Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, WA, U.S.A.), I. Rigor (Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, WA, U.S.A.), H. J. Zwally (Cryospheric Sciences Branch, NASA Goddard Space Flight Center, Greenbelt, MD, U.S.A.), and D. Yi (SGT, Inc., NASA Goddard Space Flight Center, Greenbelt, MD, U.S.A.)

Abstract

We present our best estimate of the thickness and volume of the Arctic Ocean ice cover from 10 Ice, Cloud, and land Elevation Satellite (ICESat) campaigns that span a 5-year period between 2003 and 2008. Derived ice drafts are consistently within 0.5 m of those from a submarine cruise in mid-November of 2005 and 4 years of ice draft profiles from moorings in the Chukchi and Beaufort seas. Along with a more than 42% decrease in multi-year (MY) ice coverage since 2005, there was a remarkable thinning of ∼0.6 m in MY ice thickness over 4 years. In contrast, the average thickness of the seasonal ice in midwinter (∼2 m), which covered more than two-thirds of the Arctic Ocean in 2007, exhibited a negligible trend. Average winter sea ice volume over the period, weighted by a loss of ∼3000 km³ between 2007 and 2008, was ∼14,000 km³. The total MY ice volume in the winter has experienced a net loss of 6300 km³ (>40%) in the 4 years since 2005, while the first-year ice cover gained volume owing to increased overall area coverage. The overall decline in volume and thickness are explained almost entirely by changes in the MY ice cover. Combined with a large decline in MY ice coverage over this short record, there is a reversal in the volumetric and areal contributions of the two ice types to the total volume and area of the Arctic Ocean ice cover. Seasonal ice, having surpassed that of MY ice in winter area coverage and volume, became the dominant ice type. It seems that the near-zero replenishment of the MY ice cover after the summers of 2005 and 2007, an imbalance in the cycle of replenishment and ice export, has played a significant role in the loss of Arctic sea ice volume over the ICESat record.

(Received 2 February 2009, accepted 22 April 2009, published 7 July 2009.)

Kwok, R., G. F. Cunningham, M. Wensnahan, I. Rigor, H. J. Zwally, & D. Yi (2009), Thinning and volume loss of the Arctic Ocean sea ice cover: 2003–2008, Journal of Geophysical Research, 114 (2009) C07005; doi:10.1029/2009JC005312.

Link to abstract: http://www.agu.org/pubs/crossref/2009/2009JC005312.shtml