Spatial variability of bottum turbulence over a linear sand ridge mooring deployment and AUTOSUB AUV survey cruise report R/V RRS Challenger, cruise number 146, Broken Bank, North Sea, U.K., 17th-28th August 1999 cruise report
Two successful AUTOSUB deployments were carried out during August 1999 as part of the AUTOSUB
Thematic Program project titled “Spatial Variability of Bottom Turbulence over a Linear Sand Ridge,” funded
by the Natural Environment Research Council (NERC), U.K. The AUTOSUB Autonomous Underwater Vehicle
(AUV) was deployed and used to survey flow patterns at a location near the Broken Bank, southern North Sea,
U.K. The AUV was equipped with acoustic flow and turbulence sensors and its surveys aimed at mapping the
spatial variation of flow and turbulence near the bed and over topographic features.
Three instrumented bottom mounted frames were also deployed, around the AUV survey area, for a period of
approximately 5 days. The purpose of this array was to gather information on the temporal variability of the flow
and turbulence near the seabed and to identify the important terms that drive circulation around the bank.
Additional data were gathered including CTD casts, seabed samples and acoustic images of the seabed (side-scan
The purpose of this data collection was to help identify the flow patterns around ridges and to understand the
mechanisms controlling the maintenance and evolution of such features.
This report describes the operations carried out by researchers from the University of South Carolina, Woods
Hole Oceanographic Institution, Southampton Oceanography Centre and the AUTOSUB Team on the R.V. RRS
Challenger during the period 17th –28th August 1999.