The influence of an Antarctic glacier tongue on near-field ocean circulation and mixing

• Published in: Journal of Geophysical Research: Oceans
• Main Authors: Stevens, CL, McPhee, MG, Forrest, AL, Leonard, GH, Stanton, T, Haskell, TG
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley-Blackwell Publishing, Inc. 2014
• Subjects: Earth Sciences; Oceanography; Physical oceanography; Antarctic; Erebus Glacier; Erebus Glacier Tongue; The Antarctic; Antarc*; Ice Sheet
• Online Access: https://doi.org/10.1002/2013JC009070; http://ecite.utas.edu.au/91376

In situ measurements of flow and stratification in the vicinity of the Erebus Glacier Tongue, a12 km long floating Antarctic glacier, show the significant influence of the glacier. Three ADCPs (75, 300,and 600 kHz) were deployed close (<50 m) to the sidewall of the glacier in order to capture near-field flowdistortion. Scalar (temperature and conductivity) and shear microstructure profiling captured small-scalevertical variability. Flow magnitudes exceeded 0.3 m s21 through a combination of tidal flow (~8 cm s -1 )and a background/residual flow (~4-10 cm s -1 ) flowing to the NW. Turbulence was dominated by deepermixing during spring tide, likely indicative of the role of bathymetric variation which locally forms an obstacleas great as the glacier. During the neap tide, near-surface mixing was as energetic as that seen in thespring tide, suggesting the presence of buoyancy-driven near-surface flows. Estimates of integrated dissipationrate suggest that these floating extensions of the Antarctic ice sheet alter energy budgets throughenhanced dissipation, and thus influence coastal near-surface circulation.