FN Archimer Export Format PT J TI Generation of sub-surface anticyclones at Arctic surface fronts due to a surface stress BT AF Brannigan, Liam Johnson, Helen Lique, Camille Nycander, Jonas Nilsson, Johan AS 1:1;2:2;3:3;4:1;5:1; FF 1:;2:;3:PDG-ODE-LOPS-OH;4:;5:; C1 Dept. of Meteorology, Stockholm University, Sweden Earth Sciences, University of Oxford, UK Laboratoire d’Oceanographie Physique et Spatiale, UMR 6523, CNRS-IFREMER-IRD-UBO, Brest, France C2 UNIV STOCKHOLM, SWEDEN UNIV OXFORD, UK IFREMER, FRANCE SI BREST SE PDG-ODE-LOPS-OH UM LOPS IN WOS Ifremer jusqu'en 2018 copubli-europe IF 3.086 TC 11 UR https://archimer.ifremer.fr/doc/00396/50763/51476.pdf LA English DT Article AB Isolated anticyclones are frequently observed below the mixed layer in the Arctic Ocean. Some of these sub-surface anticyclones are thought to originate at surface fronts. However, previous idealized simulations with no surface stress show that only cyclone-anticyclone dipoles can propagate away from baroclinically unstable surface fronts. Numerical simulations of fronts subject to a surface stress presented here show that a surface stress in the same direction as the geostrophic flow inhibits dipole propagation away from the front. On the other hand, a surface stress in the opposite direction to the geostrophic flow helps dipoles to propagate away from the front. Regardless of the surface stress at the point of dipole formation, these dipoles can be broken up on a timescale of days when a surface stress is applied in the right direction. The dipole breakup leads to the deeper anticyclonic component becoming an isolated sub-surface eddy. The breakup of the dipole occurs because the cyclonic component of the dipole in the mixed layer is subject to an additional advection due to the Ekman flow. When the Ekman transport has a component oriented from the anticyclonic part of the dipole towards the cyclonic part then the cyclone is advected away from the anticyclone and the dipole is broken up. When the Ekman transport is in other directions relative to the dipole axis it also leads to deviations in the trajectory of the dipole. A scaling is presented for the rate at which the surface cyclone is advected that holds across a range of mixed layer depths and surface stress magnitudes in these simulations. The results may be relevant to other regions of the ocean with similar near-surface stratification profiles. PY 2017 PD NOV SO Journal of Physical Oceanography SN 0022-3670 PU American Meteorological Society VL 47 IS 11 UT 000417674100001 BP 2653 EP 2671 DI 10.1175/JPO-D-17-0022.1 ID 50763 ER EF