Observing arctic coastal hydrography using the REMUS AUV

The region offshore of Barrow, Alaska, between the coast and the eastern flank of Barrow Canyon is an important location along the pathway of Pacific Water flowing from the Bearing Strait to the Arctic Basin. In winter, the region is ice covered and hydrographic observations are difficult to obtain using conventional techniques. The length scales and water depths in this region are well suited to the capabilities of small, propeller driven autonomous underwater vehicles (AUVs). A series of activities were undertaken in preparation for use of an AUV to measure hydrographic conditions beneath the ice in winter: A pilot study using an AUV to measure temperature, salinity and currents offshore of Point Barrow was carried out over a period of two weeks in the summer of 2005, navigation trials were conducted to document the dead-reckoning performance of the AUV, and a field survey was conducted in March 2008 to assess surface ice conditions and subsurface acoustic ranging performance.