Sea ice thickness and iceberg distribution in the Southern Ocean

• Main Author: Banks, Christopher J.
• Format: Thesis
• Language: unknown
• Published: The Open University 2007
• Subjects: Amundsen Sea; Antarctic; Southern Ocean; The Antarctic; Antarc*; Iceberg*; Sea ice
• Online Access: https://dx.doi.org/10.21954/ou.ro.0000d56b; http://oro.open.ac.uk/id/eprint/54635

The sea ice thickness distribution, represented by the probability density function (PDF), is critical to Earth's climate system and knowledge of the distribution in the Antarctic is limited. A novel methodology, using an acoustic Doppler current profiler, was developed to measure sea ice draft based on measurements taken from Autosub (an autonomous underwater vehicle). The PDF has been derived for three missions undertaken in the eastern Amundsen Sea during March 2003. The PDFs for all missions were found to have a single mode although there is evidence for variability in mean thickness along the ice front, as the most western mission has a lower mean draft. Geostatistical analyses of the data have allowed the derivation of PDFs to account for the spatial sampling. A factor on the thickness of ice measured is the presence of icebergs within a study region. This thesis reports on work carried out to investigate whether a correction to the sea ice thickness PDF can be made to account for icebergs and over what scale(s) this correction is valid. To answer this question data from Autosub and satellite images were used to investigate whether icebergs were randomly distributed both in open ocean and within sea ice. In conclusion, it was found that icebergs do cluster on the scale of typical Autosub missions (~few km). However, there are differences between icebergs in sea ice compared with open water. Therefore, icebergs should be accounted for in the sea ice thickness PDF.