High interannual variability of sea ice thickness in the Arctic region

Possible future changes in Arctic sea ice cover and thickness, and consequent changes in the ice-albedo feedback, represent one of the largest uncertainties in the prediction of future temperature rise. Knowledge of the natural variability of sea ice thickness is therefore critical for its representation in global climate models. Numerical simulations suggest that Arctic ice thickness varies primarily on decadal timescales owing to changes in wind and ocean stresses on the ice, but observations have been unable to provide a synoptic view of sea ice thickness, which is required to validate the model results. Here we use an eight-year time-series of Arctic ice thickness, derived from satellite altimeter measurements of ice freeboard, to determine the mean thickness field and its variability from 65° N to 81.5° N. Our data reveal a high-frequency interannual variability in mean Arctic ice thickness that is dominated by changes in the amount of summer melt, rather than by changes in circulation. Our results suggest that a continued increase in melt season length would lead to further thinning of Arctic sea ice.

[1]  P. Lemke,et al.  On the decrease of Arctic sea ice volume , 2000 .

[2]  R. Bourke,et al.  Contour mapping of Arctic basin ice draft and roughness parameters , 1992 .

[3]  E. Hunke,et al.  Recent Arctic change simulated with a coupled ice‐ocean model , 2001 .

[4]  David Rind,et al.  The Role of sea ice in 2×CO2 climate model sensitivity: Part II: Hemispheric dependencies , 1997 .

[5]  P. Wadhams,et al.  An Analysis Of Ice Profiles Obtained By Submarine Sonar In The Beaufort Sea , 1980, Journal of Glaciology.

[6]  Walter B. Tucker,et al.  Indirect measurements of the mass balance of summer Arctic sea ice with an electromagnetic induction technique , 2001, Annals of Glaciology.

[7]  Tang Ze.  Achievements and prospects of the bioscience , 2000 .

[8]  Vladimir F. Radionov,et al.  Snow Depth on Arctic Sea Ice , 1999 .

[9]  Seymour W. Laxon,et al.  Sea surface height determination in the Arctic Ocean from ERS altimetry , 2004 .

[10]  Syukuro Manabe,et al.  Transient responses of a coupled ocean-atmosphere model to gradual changes of atmospheric CO2 , 1991 .

[11]  D. Rothrock,et al.  Thinning of the Arctic sea‐ice cover , 1999 .

[12]  Marvin L. Johnson,et al.  Seasonal cycles in two regimes of Arctic climate , 1999 .

[13]  V. F. Radionov,et al.  The snow cover of the Arctic basin , 1997 .

[14]  J. Houghton,et al.  Climate change 2001 : the scientific basis , 2001 .

[15]  P. Stott,et al.  Recent and future changes in Arctic sea ice simulated by the HadCM3 AOGCM , 2002 .

[16]  I. Polyakov,et al.  Arctic decadal and interdecadal variability , 2000 .

[17]  A. Pinder,et al.  Achievements and prospects. , 1985, Immunology today.

[18]  Peter Wadhams,et al.  Further evidence of ice thinning in the Arctic Ocean , 2000 .

[19]  Jinlun Zhang,et al.  The arctic ice thickness anomaly of the 1990s: A consistent view from observations and models , 2003 .

[20]  D. Rothrock,et al.  Role of rafting in the mechanical redistribution of sea ice thickness , 2002 .

[21]  Saibun Tjuatja,et al.  Laboratory measurements of radar backscatter from bare and snow-covered saline ice sheets , 1995 .

[22]  D. Rothrock,et al.  Recent Changes in Arctic Sea Ice: The Interplay between Ice Dynamics and Thermodynamics , 2000 .

[23]  Peter Wadhams,et al.  The freshwater budget of the Arctic Ocean , 2000 .

[24]  Peter Wadhams,et al.  Relationship between sea ice freeboard and draft in the Arctic Basin, and implications for ice thickness monitoring , 1992 .

[25]  Ron Lindsay,et al.  Arctic sea ice leads from advanced very high resolution radiometer images , 1995 .

[26]  Greg Holloway,et al.  Has Arctic Sea Ice Rapidly Thinned , 2002 .

[27]  J. Sacks,et al.  Artic sea ice variability: Model sensitivities and a multidecadal simulation , 1994 .

[28]  Douglas M. Smith.  Recent increase in the length of the melt season of perennial Arctic sea ice , 1998 .

[29]  R. E. Moritz,et al.  Do General Circulation Models Underestimate the Natural Variability in the Arctic Climate , 1997 .

[30]  M. Steele,et al.  Sea Ice Growth, Melt, and Modeling: A Survey , 2000 .

[31]  Hajo Eicken,et al.  Interannual variability of summer sea ice thickness in the Siberian and central Arctic under different atmospheric circulation regimes , 2001 .

[32]  Walter B. Tucker,et al.  Evidence for rapid thinning of sea ice in the western Arctic Ocean at the end of the 1980s , 2001 .

[33]  D. Carson,et al.  Climate modelling: Achievements and prospects , 1999 .