Observation and parameterization of small icebergs: Drifting breakwaters in the southern ocean

The variability of small-size iceberg distributions is revealed from a novel analysis of satellite altimeter data. A strong annual cycle is modulated by pulse-like events confined to single ocean basins, with dense iceberg populations in the South Atlantic in 2004–2005, and in the South Pacific in 2008. Anomalies in sea surface temperatures of the order of 1 °C may be related to the iceberg distribution. Icebergs also appear very strongly associated with anomalies in the heights of ocean waves. A preliminary parameterization of wave blocking by icebergs significantly reduces wave model errors in the region south of 45° South, and has a perceptible influence on all the west coasts of the Southern hemisphere.

[1]  Jean Tournadre,et al.  Iceberg detection in open water by altimeter waveform analysis. , 2008 .

[2]  Tiago H. Silva,et al.  Contribution of giant icebergs to the Southern Ocean freshwater flux , 2006 .

[3]  Kenneth L. Smith,et al.  Free-Drifting Icebergs: Hot Spots of Chemical and Biological Enrichment in the Weddell Sea , 2007, Science.

[4]  P. Wadhams.  Winter observations of iceberg frequencies and sizes in the south Atlantic Ocean , 1988 .

[5]  Hendrik L. Tolman,et al.  A mosaic approach to wind wave modeling , 2008 .

[6]  E. Rogers,et al.  Semiempirical Dissipation Source Functions for Ocean Waves. Part I: Definition, Calibration, and Validation , 2009, 0907.4240.

[7]  Steve Neshyba,et al.  On the size distribution of Antarctic icebergs , 1980 .

[8]  D. Holland.  Computing marine-ice thickness at an ice-shelf base , 2002, Journal of Glaciology.

[9]  W. Munk,et al.  Wind, sea, and swell : Theory of relations for forecasting , 1947 .

[10]  Fabrice Ardhuin,et al.  Observation and estimation of Lagrangian, Stokes and Eulerian currents induced by wind and waves at the sea surface , 2008, 0810.3537.

[11]  Rupert Gladstone,et al.  Iceberg trajectory modeling and meltwater injection in the Southern Ocean , 2001 .

[12]  Thomas M. Smith,et al.  An Improved In Situ and Satellite SST Analysis for Climate , 2002 .

[13]  D. J. Goodman,et al.  The Flexural Response of a Tabular Ice Island to Ocean Swell , 1980, Annals of Glaciology.

[14]  Fabrice Ardhuin,et al.  A global wave parameter database for geophysical applications. Part 1: Wave-current turbulence interaction parameters for the open ocean based on traditional parameterizations , 2008 .

[15]  W. G. Rees,et al.  A technique for the identification and analysis of icebergs in synthetic aperture radar images of Antarctica , 1999 .

[16]  T. H. Jacka,et al.  Antarctic iceberg distribution and dissolution from ship-based observations , 2007 .

[17]  M. Meylan.  Wave response of an ice floe of arbitrary geometry , 2002 .

[18]  B. Chapron,et al.  Extraction of coastal ocean wave fields from SAR images , 2005, IEEE Journal of Oceanic Engineering.

[19]  Peter Wadhams,et al.  Of Ocean Waves and Sea Ice , 1995 .

[20]  Bertrand Chapron,et al.  Observation of swell dissipation across oceans , 2008, 0809.2497.

[21]  C. Fox,et al.  Toward realism in modeling ocean wave behavior in marginal ice zones , 1997 .

[22]  Hendrik L. Tolman,et al.  Treatment of unresolved islands and ice in wind wave models , 2003 .