Observations from 38 bottom‐moored Current and Pressure Recording Inverted Echo Sounders (CPIES) ... more Observations from 38 bottom‐moored Current and Pressure Recording Inverted Echo Sounders (CPIES) deployed in Drake Passage during the 2007–2008 International Polar Year provide unprecedented coverage of near‐bottom currents and pressures spanning the entire Antarctic Circumpolar Current. Year‐long‐mean currents exceed 10 cm s−1 north of the Polar Front, and mean directions are not, in general, aligned with the surface fronts. Topographic steering is most evident at the continental margins. Deep eddy kinetic energy (EKE) is maximum at about 200 cm2 s−2 between the Subantarctic and Polar Fronts, coinciding with the location but about one quarter of the value of a maximum in surface EKE. Multiple high‐speed current events, with peak speeds of 60–70 cm s−1 and lasting 30 to 70 days, are coherent across sites separated by 45 km. The observed spinup of eddies coinciding with meanders in the surface fronts is consistent with deep cyclogenesis.
Using acoustic Doppler current profiler (ADCP) observations made between 1999 and 2002, we examin... more Using acoustic Doppler current profiler (ADCP) observations made between 1999 and 2002, we examine the mean jets and mesoscale variability in the surface layer velocity structure of the Antarctic Circumpolar Current (ACC) in Drake Passage. The data were acquired from an ongoing sampling program of underway ADCP observations from the U.S. Antarctic icebreakers, RVIB Laurence M. Gould and RVIB Nathaniel B. Palmer, supported by the NSF Office of Polar Programs. The L. M. Gould crosses Drake Passage approximately 2-4 times per month, and its track across the passage varies although the duration of each crossing is about 2 days. The northern starting point is always Isla de los Estados at the southeast tip of Tierra del Fuego, but the southern end point varies, exiting Drake Passage between 55-65 degrees W. We examine the Eulerian velocity statistics both by spatial binning as well as projected onto a mean section. The ACC is characterized by a series of relatively narrow eastward jets, ...
Internal wavewave interaction theories and observations support a parameterization for the turbu... more Internal wavewave interaction theories and observations support a parameterization for the turbulent dissipation rate ε and eddy diffusivity K that depends on internal wave shear V z 2 and strain ξ z 2 variances. Its latest incarnation is applied to about 3500 lowered ADCP/CTD ...
Page 1. Journal of Marine Research, 65, 2758, 2007 Mean jets, mesoscale variability and eddy mom... more Page 1. Journal of Marine Research, 65, 2758, 2007 Mean jets, mesoscale variability and eddy momentum fluxes in the surface layer of the Antarctic Circumpolar Current in Drake Passage by Y.-D. Lenn1,2, TK Chereskin1, J. Sprintall1, and E. Firing3 ...
The structure of the Antarctic Circumpolar Current (ACC) in Drake Passage is examined using 4.5 y... more The structure of the Antarctic Circumpolar Current (ACC) in Drake Passage is examined using 4.5 years of shipboard acoustic Doppler current profiler (ADCP) velocity data. The extended 1000 m depth range available from the 38 kHz ADCP allows us to investigate the vertical structure of the current. The mean observed current varies slowly with depth, while eddy kinetic energy and shear variance exhibit strong depth dependence. Objectively mapped streamlines are self-similar with depth, consistent with an equivalent barotropic ...
Deep Sea Research Part II: Topical Studies in Oceanography, 2002
... Permissions & Reprints. The JADE and WOCE I10/IR6 Throughflow sections in the... more ... Permissions & Reprints. The JADE and WOCE I10/IR6 Throughflow sections in the southeast Indian Ocean. ... The square boxes mark the locations of the JADE and WOCE hydrographic stations used to form the reference curves for the normalized salinity anomalies (see text). ...
Observations from 38 bottom‐moored Current and Pressure Recording Inverted Echo Sounders (CPIES) ... more Observations from 38 bottom‐moored Current and Pressure Recording Inverted Echo Sounders (CPIES) deployed in Drake Passage during the 2007–2008 International Polar Year provide unprecedented coverage of near‐bottom currents and pressures spanning the entire Antarctic Circumpolar Current. Year‐long‐mean currents exceed 10 cm s−1 north of the Polar Front, and mean directions are not, in general, aligned with the surface fronts. Topographic steering is most evident at the continental margins. Deep eddy kinetic energy (EKE) is maximum at about 200 cm2 s−2 between the Subantarctic and Polar Fronts, coinciding with the location but about one quarter of the value of a maximum in surface EKE. Multiple high‐speed current events, with peak speeds of 60–70 cm s−1 and lasting 30 to 70 days, are coherent across sites separated by 45 km. The observed spinup of eddies coinciding with meanders in the surface fronts is consistent with deep cyclogenesis.
Using acoustic Doppler current profiler (ADCP) observations made between 1999 and 2002, we examin... more Using acoustic Doppler current profiler (ADCP) observations made between 1999 and 2002, we examine the mean jets and mesoscale variability in the surface layer velocity structure of the Antarctic Circumpolar Current (ACC) in Drake Passage. The data were acquired from an ongoing sampling program of underway ADCP observations from the U.S. Antarctic icebreakers, RVIB Laurence M. Gould and RVIB Nathaniel B. Palmer, supported by the NSF Office of Polar Programs. The L. M. Gould crosses Drake Passage approximately 2-4 times per month, and its track across the passage varies although the duration of each crossing is about 2 days. The northern starting point is always Isla de los Estados at the southeast tip of Tierra del Fuego, but the southern end point varies, exiting Drake Passage between 55-65 degrees W. We examine the Eulerian velocity statistics both by spatial binning as well as projected onto a mean section. The ACC is characterized by a series of relatively narrow eastward jets, ...
Internal wavewave interaction theories and observations support a parameterization for the turbu... more Internal wavewave interaction theories and observations support a parameterization for the turbulent dissipation rate ε and eddy diffusivity K that depends on internal wave shear V z 2 and strain ξ z 2 variances. Its latest incarnation is applied to about 3500 lowered ADCP/CTD ...
Page 1. Journal of Marine Research, 65, 2758, 2007 Mean jets, mesoscale variability and eddy mom... more Page 1. Journal of Marine Research, 65, 2758, 2007 Mean jets, mesoscale variability and eddy momentum fluxes in the surface layer of the Antarctic Circumpolar Current in Drake Passage by Y.-D. Lenn1,2, TK Chereskin1, J. Sprintall1, and E. Firing3 ...
The structure of the Antarctic Circumpolar Current (ACC) in Drake Passage is examined using 4.5 y... more The structure of the Antarctic Circumpolar Current (ACC) in Drake Passage is examined using 4.5 years of shipboard acoustic Doppler current profiler (ADCP) velocity data. The extended 1000 m depth range available from the 38 kHz ADCP allows us to investigate the vertical structure of the current. The mean observed current varies slowly with depth, while eddy kinetic energy and shear variance exhibit strong depth dependence. Objectively mapped streamlines are self-similar with depth, consistent with an equivalent barotropic ...
Deep Sea Research Part II: Topical Studies in Oceanography, 2002
... Permissions & Reprints. The JADE and WOCE I10/IR6 Throughflow sections in the... more ... Permissions & Reprints. The JADE and WOCE I10/IR6 Throughflow sections in the southeast Indian Ocean. ... The square boxes mark the locations of the JADE and WOCE hydrographic stations used to form the reference curves for the normalized salinity anomalies (see text). ...
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Papers by Teresa Chereskin