Boundary Layer Velocity Structure in a Coldwater Coral Area of Haddock Channel, Southwest Grand Banks

William Fowler

MSc. Candidate Environmental Science

Memorial University of Newfoundland

Large Gorgonian Distribution

Coldwater Coral off Newfoundland and Labrador, WWF 2007

Characterization of Local Current Regime Corals occurring on the

bottom in deep water are located in the benthic boundary layer

Layer extends above seafloor anywhere from 5-20 meters

Dr. Len Zedel / Dr. Evan Edinger, ROPOS 2007

Boundary Layers

Idealized boundary layer

Bottom drag, sea floor roughness important factor

NASA 2008

Methods

ROPOS/Hudson 2007 Cruise

Survey of deepwater coral

Multiple sites along slope of continental shelf

2008 Dr. Evan Edinger

ADCP

Profiler 1: Area without Coral

Dr. Len Zedel / Dr. Evan Edinger, ROPOS 2007

Current Profiler 2: Coral Thicket

Dr. Len Zedel / Dr. Evan Edinger, ROPOS 2007

Deployment Parameters

Depth 700 meters 1 profile every 30 seconds Uncertainty in velocity time series ~ 0.5 cm/s Profiling over 4 meters 1 meter cell size

Location of ADCP in Coral Thicket (site 2)

ROPOS Transact and location of coral

Mean normalized velocity profile

Comparison of Site 1 and 2

Directional Velocity Profile: Inst. 1

Coral Thicket varies relative to site 1

Directional Velocity Profile w/ time series

Directional subplots Inst. 1 shown (use inst. 2 plots in presentation)