Wavenumber Spectra in Drake Passage from models, altimetry, and ADCP: Connecting theory to observations

Sarah Gille (Scripps Institution of Oceanography, UC San Diego, United States)

CoAuthors

Teresa Chereskin (Scripps Institution of Oceanography, UC San Diego, United States); Bruce Cornuelle (Scripps Institution of Oceanography, UC San Diego, United States); Matthew Mazloff (Scripps Institution of Oceanography, UC San Diego, United States); Cesar Rocha (Scripps Institution of Oceanography, UC San Diego, United States); Jinbo Wang (Scripps Institution of Oceanography, UC San Diego, United States)

Event: 2014 Ocean Surface Topography Science Team Meeting

Session: Science Results from Satellite Altimetry: Finer scale ocean processes (mesoscale and coastal)

Presentation type: Type Oral

Wavenumber spectra in the upper ocean have been hypothesized to have slopes determined either by quasi-geostrophic (QG) or surface quasi-geostrophic (SQG) theory. In previous analyses of Gulf Stream observations, wavenumber spectra deviated from QG and SQG theory, and this was attributed in part to internal wave effects. The Southern Ocean offers a different environment for testing these theories: the first baroclinic Rossby radius in the Southern Ocean is estimated to be as small as 10 to 20 km (implying eddies with a typical diameter as small as 60 km), much smaller than in mid-latitudes. This study compares two high-resolution data sets with altimeter products with different intrinsic spatial resolution and different levels of smoothing. The region of focus is the Drake Passage. Shipboard acoustic Doppler current profiler (ADCP) observations with horizontal resolution of 5 km have been collected in all seasons from the US Antarctic supply vessel ARSV Laurence M. Gould since 1999, providing 288 velocity transects for use in this study. New 1-km resolution MITgcm model simulations are also considered for the Drake Passage region. We compare these with a series of high-wavenumber along-track altimeter products, including X-Track and PISTACH, which have been developed specifically to retain small scale structures for coastal studies.
 

Oral presentation show times:

RoomStart DateEnd Date
Red salon Wed, Oct 29 2014,14:15 Wed, Oct 29 2014,14:30
Sarah Gille
Scripps Institution of Oceanography, UC San Diego
United States
sgille@ucsd.edu