Publication Date:
2023-06-01
Description:
The ocean influences on mass loss at tidewater glaciers are poorly understood, leading to uncertainty in sea level rise projections. Subglacial discharge plumes drive mass loss via submarine melting and may also facilitate mass loss by modulating calving rates. However, current theories underpredict submarine melt rates at terminus regions that are far from discharge plumes, suggesting that they may miss key ocean processes. A new set of observations from autonomously deployed moorings less than 100 m from the terminus of LeConte Glacier, Alaska, and a high-resolution numerical model, reveal that the near-glacier ocean is filled with energetic internal waves. We find that the internal wave kinetic energy and frequency are correlated with subglacial discharge fluxes on weekly to seasonal timescales. The waves radiate away from the discharge plume and could enhance ice-ocean boundary layer fluxes of heat and salt along the terminus. Accounting for waves within current submarine melt rate parameterizations increases predicted melt rates by up to 70%. Because the dynamical ingredients - a buoyant plume rising through a stratified ocean - are common to many tidewater glacier systems, such internal waves are likely to be widespread.
Language:
English
Type:
info:eu-repo/semantics/conferenceObject
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