MEAN BAROCLINIC STRUCTURE OF POLAR FRONT IN STREAM COORDINATES NEAR SHACKLETON FRACTURE ZONE
The baroclinic structure of the Polar Front (PF) as it flows through Drake Passage is investigated in a stream coordinate system. A line of cPIES deployed during the cDrake experiment provides twice-daily records of acoustic travel time, which is converted into geopotential height using a Gravest Empirical Mode analysis. We find the maximum gradient in geopotential height (at the surface, referenced to the bottom) tends be to preferentially located north (downstream) or south (upstream) of the Shackleton Frature Zone (SFZ), rarely appearing directly over the ridge. The geopotential height is, on average, ~20cm higher at times when the PF is north of SFZ. Composite mean geostrophic velocity shears are referenced to the bottom, and even with such different core values, the general structure of the jet remains similar. Surface velocities reach speeds near 50cm/s and the core of the jet has a width of about 100km. Near-surface relative vorticity never exceeds 10% of the local Coriolis parameter. When downstream of SFZ, the magnitude of anticyclonic shear exceeds cyclonic shear, conversely when upstream, cyclonic shear exceeds anticyclonic shear.
Foppert, A., University of Rhode Island, USA, firstname.lastname@example.org
Donohue, K., University of Rhode Island, USA, email@example.com
Watts, D. R., University of Rhode Island, USA, firstname.lastname@example.org
Time: 16:00 - 18:00
Location: Poster/Exhibit Hall
Presentation is given by student: Yes