High‐frequency fluctuations in Denmark Strait transport

Abstract

Denmark Strait ocean current transport exhibits quasi‐regular fluctuations immediately south of the sill with periods of 2–4 days. The transport variability is similar to the mean transport itself. Using a circulation model we explore prospects to monitor the fluctuations. The model has realistic transport and shows water leaving Denmark Strait in equivalent‐barotropic cyclones that are nearly geostrophic and correlate with sea‐surface height (SSH). Existing satellite altimeter observations of SSH have adequate space/time sampling to reconstruct the transport fluctuations using a regression developed from the model results, but measurement error overwhelms the signal. From the model results, the pending Surface Water and Ocean Topography (SWOT) wide‐swath altimeter appears accurate enough, and with good‐enough coverage, to allow the transport fluctuations to be reconstructed. Bottom pressure recorders at the exit of the Denmark Strait can also reproduce the transport variability.