In the poster we provide details on the content of the developed dataset and summarize the results of the study of Antarctic icebergs mean distribution and variability based on the collected data. The focus of the work is on small and medium sized icebergs ranging from 15m to several km in length. Since most observations in the dataset have been collected in the south of the Atlantic and Indian Ocean, the available statistics on the iceberg occurrence in these parts of the Southern Ocean was much more extensive than in the Pacific sector. The analysis of the dataset revealed an overall highly uneven distribution of the icebergs across the Southern Ocean. The iceberg concentration generally increases towards the coast reaching 50-100 icebergs within a circle of 15 nautical miles radius (equivalent to one iceberg per 25 -50 km²) in the vicinity of the coastal line. The mean iceberg concentration below 50°S in the Atlantic and Indian Ocean sectors of the Southern Ocean and below 54°S in the Pacific sector amounts to about 8 icebergs observed within a circle of 15 nm radius (which is equivalent to one iceberg per ~ 311 km²). The estimated variability of the iceberg concentration amounts to about 100% of the mean iceberg concentration value at a particular location. There are three well pronounced clusters of elevated values of the iceberg concentration in the Atlantic Ocean within 0°–60° W, in the Indian Ocean within 40°–120° E and in the Southern Pacific within 90°–170°W (see the map of the mean iceberg concentration below). The area in the Atlantic Ocean corresponding to the Weddell Sea has the maximum northward extension with large numbers of icebergs north of 50°S. We explain the development of these clusters by the location and productivity of outlet glaciers and ice fields, prevailing ocean currents, specifics of the ocean floor topography and atmospheric circulation. It is shown that at least in the Atlantic and Indian Ocean the iceberg distribution pattern experiences long-term variations well-correlated with El Nino/Southern Oscillation (ENSO) events. The strongest effect is observed in the region east of the Drake Passage where the iceberg concentration increases by about 50% during years of the negative ENSO phase.
We further combined the iceberg concentration data combined with information on the iceberg size and shape distribution to estimate the area-wide cumulative characteristics of Antarctic icebergs. The instantaneous number of icebergs in the Southern Ocean was estimated as 132 269 with an uncertainty of 7%. The area and volume of icebergs were equal correspondingly to 55 805 km² and 16 893 km³ with uncertainties of 32–33%. Our estimates of the total number and area of Antarctic icebergs are generally within the range of values obtained by other authors; however the estimated total volume of ice in the icebergs is mostly larger than earlier estimates.