Submarine Upward Looking Sonar
Ice draft profile data and statistics

Processing and analysis of ice draft profile data from Royal Navy submarine cruises to the Arctic Ocean was carried out during the period 1971 to the present. These datasets have been released to us from the UK Hydrographic Office, Taunton and have been processed to allow their declassification and release. Older data is held in the form of paper chart records which have required digitising. This project was started when the group was based in the Scott Polar Research Institute.

The project was a collaboration with the US Army Cold Regions Research & Engineering Laboratory (CRREL) in Hanover, New Hampshire, USA, which has been working on the release of US Navy data.

The data set consists of upward looking sonar draft data collected by submarines in the Arctic Ocean from cruises in 1976, 1987 and 1991. The data set will be augmented by data from additional cruises dating back to 1971, as the data becomes available. Also available is the data collected by US Navy submarines in 1992 and 1994, and the 1993, 1996 and 1997 data sets from the SCICEX programme. See the map showing the submarine tracks.

A public copy of this dataset (including data from U.S. Navy submarines) is available from the National Snow & Ice Data Center (NSIDC) in Boulder, Colorado, USA.

Data in this dataset are saved in two types of files: one for ice draft profiles and the other for statistics derived from the profile data. Ice draft files include a header that gives date and location information followed by a sequential list of drafts spaced at 1.0 m intervals that comprise the bottom-side sea-ice roughness profile. The length of the profile in any given file can be up to 50.0 km, but may be shorter if data dropouts create gaps greater than 0.25 km, or if changes in course cause deviations from a straight-line track. Statistics files that include information concerning ice draft characteristics, keels, level ice, leads, and undeformed- and deformed-ice are provided for all draft profiles that exceed 10.0 km in length.

The upward-looking sonar data from the U.S. Navy was interpolated and processed for release as unclassified data at the US Army Cold Regions Research and Engineering Laboratory (CRREL) in Hanover, New Hampshire. Data from the SCICEX-97 cruise was provided by the Polar Science Center, Applied Physics Laboratory, University of Washington. All data sources used the same basic processing methods in order to ensure a consistent data set.

This project was initially funded by grants from the UK Natural Environment Research Council (NERC), the US National Science Foundation (NSF) and the US Army. It is now part of the AICSEX project.