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

• Main Authors: Stevens, C.L., McPhee, M.G., Forrest, A.L., Leonard, G.H., Stanton, Timothy P., Haskell, T.G.
• Other Authors: Oceanography
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: AGU Publications 2014
• Subjects: Antarctic; Erebus Glacier; Erebus Glacier Tongue; Marsden; New Zealand; Stanton; The Antarctic; Antarc*; Antarctica; Antarctica New Zealand; Ice Sheet
• Online Access: https://hdl.handle.net/10945/46142

The article of record as published may be located at http://dx.doi.org/10.1002/2013JC009070 In situ measurements of flow and stratification in the vicinity of the Erebus Glacier Tongue, a 12 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 flow distortion. Scalar (temperature and conductivity) and shear microstructure profiling captured small-scale vertical variability. Flow magnitudes exceeded 0.3 m s21 through a combination of tidal flow ( 8 cm s21) and a background/residual flow ( 4–10 cm s21) flowing to the NW. Turbulence was dominated by deeper mixing during spring tide, likely indicative of the role of bathymetric variation which locally forms an obstacle as great as the glacier. During the neap tide, near-surface mixing was as energetic as that seen in the spring tide, suggesting the presence of buoyancy-driven near-surface flows. Estimates of integrated dissipation rate suggest that these floating extensions of the Antarctic ice sheet alter energy budgets through enhanced dissipation, and thus influence coastal near-surface circulation. The work was funded by The New Zealand Royal Society administered Marsden Fund, and US NSF support to Stanton and McPhee. Logistic support was provided by Antarctica New Zealand and travel funding from Air New Zealand.