Journal ArticleDOI
Near-surface structure of the Antarctic Circumpolar Current derived from World Ocean Circulation Experiment drifter data
Reads0
Chats0
TLDR
In this paper, the mean surface current field was derived using natural bicubic splines, whose application yielded a high-resolution mean flow which allowed a detailed description for ACC meridional shear as well as its jets.Abstract:
[1] In this work, the dynamics of the Antarctic Circumpolar Currrent (ACC) are investigated on the basis of near-surface Lagrangian observations carried out under the framework of the World Ocean Circulation Experiment (WOCE) and contained within the WOCE drifter data set. Approximately 440 drifters that were deployed in the Southern Ocean, between 1995 and 2002, were considered during the study. The mean surface current field was derived using natural bicubic splines, whose application yielded a high-resolution mean flow which allowed a detailed description for ACC meridional shear as well as its jets. ACC volume transport was estimated using a novel approach that was based upon the surface transport that was computed on the basis of drifter data and by assuming an exponential form for vertical current shear. The volume transport was determined to be 133 Sv for an e folding depth of 1000 m. Lagrangian diffusivities and integral parameters were derived by assuming a broadly homogenous eddy field. The zonal and meridional diffusivity components were determined to be 9 × 107 and 2 × 107 cm2 s−1, respectively. The eddy field is described in terms of the eddy kinetic energy distribution.read more
Citations
More filters
Journal ArticleDOI
Global ocean surface velocities from drifters: Mean, variance, El Niño–Southern Oscillation response, and seasonal cycle
Rick Lumpkin,Gregory C. Johnson +1 more
Abstract: [1] Global near-surface currents are calculated from satellite-tracked drogued drifter velocities on a 0.5° × 0.5° latitude-longitude grid using a new methodology. Data used at each grid point lie within a centered bin of set area with a shape defined by the variance ellipse of current fluctuations within that bin. The time-mean current, its annual harmonic, semiannual harmonic, correlation with the Southern Oscillation Index (SOI), spatial gradients, and residuals are estimated along with formal error bars for each component. The time-mean field resolves the major surface current systems of the world. The magnitude of the variance reveals enhanced eddy kinetic energy in the western boundary current systems, in equatorial regions, and along the Antarctic Circumpolar Current, as well as three large “eddy deserts,” two in the Pacific and one in the Atlantic. The SOI component is largest in the western and central tropical Pacific, but can also be seen in the Indian Ocean. Seasonal variations reveal details such as the gyre-scale shifts in the convergence centers of the subtropical gyres, and the seasonal evolution of tropical currents and eddies in the western tropical Pacific Ocean. The results of this study are available as a monthly climatology.
Journal ArticleDOI
An improved near-surface velocity climatology for the global ocean from drifter observations
TL;DR: In this article, an improved near-surface velocity climatology for the global ocean using observations from undrogued and 15m drogued Global Drifter Program (GDP) drifters is presented.
Journal ArticleDOI
Advection in polar and sub-polar environments: Impacts on high latitude marine ecosystems
George L. Hunt,Kenneth F. Drinkwater,Kevin R. Arrigo,Jørgen Berge,Kendra L. Daly,Seth L. Danielson,Malin Daase,Malin Daase,Haakon Hop,Haakon Hop,Enrique Isla,Nina J. Karnovsky,Kristin L. Laidre,Franz Mueter,Eugene J. Murphy,Paul E. Renaud,Walker O. Smith,Philip N. Trathan,John Turner,Dieter Wolf-Gladrow +19 more
TL;DR: In this paper, the authors compare and contrast the ecological impacts of atmospheric and oceanic circulation patterns on polar and sub-polar marine ecosystems and show that circulation patterns differ strikingly between the north and south.
Journal ArticleDOI
Lagrangian Transport of Marine Litter in the Mediterranean Sea
TL;DR: In this article, the authors utilized the largest available set of historical Lagrangian data gathered in the Mediterranean Sea to estimate the probability of debris particles to reach different subareas of the basin, with the main objective of singling out possible retention areas.
Journal ArticleDOI
Rapid cross-density ocean mixing at mid-depths in the Drake Passage measured by tracer release
Andrew J. Watson,Andrew J. Watson,James R. Ledwell,Marie-José Messias,Marie-José Messias,Brian A. King,Neill Mackay,Michael P. Meredith,Michael P. Meredith,Benjamin J. W. Mills,Benjamin J. W. Mills,Alberto C. Naveira Garabato +11 more
TL;DR: Diapycnal mixing of mid-depth waters undergoes a sustained 20-fold increase as the Antarctic Circumpolar Current flows through the Drake Passage, between the southern tip of South America and Antarctica, based on an open-ocean tracer release of trifluoromethyl sulphur pentafluoride.
References
More filters
Journal ArticleDOI
On the meridional extent and fronts of the Antarctic Circumpolar Current
TL;DR: In this article, large-scale features of the Antarctic Circumpolar Current (ACC) were described using all historical hydrographic data available from the Southern Ocean, and the geopotential anomaly of the sea surface relative to 1000 db reveals the highly-sheared eastward flow of the ACC and the strong steering of the current by the ridge system around Antarctica.
Journal ArticleDOI
Diffusion by Continuous Movements
TL;DR: The influence of velocity distribution on one-particle dispersion is studied in this article, where the ensemble of particle releases is subdivided into subensembles characterized by particle velocity at the instant of release.
Journal ArticleDOI
Transport and variability of the Antarctic Circumpolar Current in Drake Passage
TL;DR: The average yearlong absolute transport is 134 Sv, and the standard deviation of the average is 11.2 Sv, consistent with previous estimates of variability in the Antarctic Circumpolar Current.
Journal ArticleDOI
Statistics from Lagrangian observations
TL;DR: In this article, a review of statistical analyses of Lagrangian data from the ocean is presented, which can be grouped into studies involving single particles and those with pairs or groups of particles.
Related Papers (5)
Lagrangian Analysis and Prediction of Coastal and Ocean Dynamics: Measuring surface currents with Surface Velocity Program drifters: the instrument, its data, and some recent results
Rick Lumpkin,Mayra Pazos +1 more