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.

► The distribution of small icebergs in the Southern Ocean was fully mapped for the first time, thanks to a novel technique.
► The distribution of icebers is quite variable.
► Icebergs have a strong impact on ocean waves.
► A parameterization of icebergs provides a much improved wave model for the Southern Ocean.
► Iceberg effects can be seen (through swells) a few thousands of kilometers away.