Isopycnal Lagrangian statistics from the North Atlantic Current RAFOS float observations

Zhang, Huai‐Min; Prater, Mark D.; Rossby, T.

doi:10.1029/1999jc000101

Cited by 74 publications

(97 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We note that the integral timescale (about 1.71 days) and the diffusivity K (1.17 × 10 3 m 2 s −1 ) are of the same order of magnitude as those found for ocean drifters (e.g., Poulain and Niiler, 1989;Zhang et al, 2001).…”

Section: Discussionmentioning

confidence: 63%

“…This is done here by following the classical approach used to study Lagrangian particle trajectories (see for example Zhang et al, 2001). This consists of splitting each trajectory into mean and fluctuating parts by using appropriate averaging scales L and T to compute the Lagrangian mean motion at any given location and time.…”

Section: Decomposition Of the Sea-ice Motionmentioning

confidence: 99%

“…The appropriate averaging scales (about 400 km and 5.5 months for winter conditions) were found small enough to clearly separate the interannual variability of the mean circulation from the fluctuating motion due to passing atmospheric perturbations, local oceanic eddies and inertial and tidal motion. This approach, based on the analysis of single particle trajectories, has been widely used to study diffusion properties of Lagrangian drifters in the ocean (see, e.g., Zhang et al, 2001;Poulain and Niiler, 1989) and is now becoming a standard analysis tool for sea-ice dynamics (Lukovich et al, 2011(Lukovich et al, , 2015Gabrielski et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Arctic sea-ice diffusion from observed and simulated Lagrangian trajectories

et al. 2016

View full text Add to dashboard Cite

Abstract. We characterize sea-ice drift by applying a Lagrangian diffusion analysis to buoy trajectories from the International Arctic Buoy Programme (IABP) dataset and from two different models: the standalone Lagrangian sea-ice model neXtSIM and the Eulerian coupled ice-ocean model used for the TOPAZ reanalysis. By applying the diffusion analysis to the IABP buoy trajectories over the period 1979-2011, we confirm that sea-ice diffusion follows two distinct regimes (ballistic and Brownian) and we provide accurate values for the diffusivity and integral timescale that could be used in Eulerian or Lagrangian passive tracers models to simulate the transport and diffusion of particles moving with the ice. We discuss how these values are linked to the evolution of the fluctuating displacements variance and how this information could be used to define the size of the search area around the position predicted by the mean drift. By comparing observed and simulated sea-ice trajectories for three consecutive winter seasons (2007)(2008)(2009)(2010)(2011), we show how the characteristics of the simulated motion may differ from or agree well with observations. This comparison illustrates the usefulness of first applying a diffusion analysis to evaluate the output of modeling systems that include a sea-ice model before using these in, e.g., oil spill trajectory models or, more generally, to simulate the transport of passive tracers in sea ice.

show abstract

Section: Discussionmentioning

confidence: 63%

Section: Decomposition Of the Sea-ice Motionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Arctic sea-ice diffusion from observed and simulated Lagrangian trajectories

et al. 2016

View full text Add to dashboard Cite

show abstract

“…This is different from other regions such as the surface over the California Current (Swenson and Niiler 1996) and subsurface in the Newfoundland Basin (Zhang et al 2001).…”

Section: A the Pdf Of Residual Velocitymentioning

confidence: 99%

Eulerian and Lagrangian Statistics in the South China Sea as Deduced from Surface Drifters

Qian

Peng

2013

Journal of Physical Oceanography

View full text Add to dashboard Cite

Eulerian and Lagrangian statistics of the surface flows over the South China Sea (SCS) are investigated based on observations of satellite-tracked Lagrangian drifters of the Surface Velocity Program. Although the dataset contains the most recent observations up to 2011, the spatial and temporal distributions of the data are quite inhomogeneous. The Luzon Strait as well as the northern and western parts of the SCS are heavily sampled by drifters whereas the internal SCS is less sampled. The overall Eulerian mean circulation derived from all drifter observations resembles the wintertime circulations because of the seasonal sampling bias toward wintertime. It is found that the calculation of the diffusivity may be misled by the low-frequency temporal variabilities such as annual cycle, which could be removed using the Gauss-Markov decomposition. In the regions around Luzon Strait, typical values of diffusivity, time scale, and length scale are 3.7-11.9 3 10 7 cm 2 s 21 , 0.8-1.9 days, and 16.4-44.4 km, respectively. In the regions around Hainan Island and the western boundary of the SCS, the typical estimated diffusivity and length scale are slightly smaller, that is, 2.3-6.9 3 10 7 cm 2 s 21 and 12.8-33.7 km while the time scale (0.8-2.0 days) is approximately the same as that in the regions around Luzon Strait. Although these regions are close to the coast, the ''flux versus gradient'' relationship is still valid in these coastal regions.

show abstract

“…However this rule is not universal. In fact, subsequent studies showed that a constant-T rule did not apply elsewhere and suggested that the diffusivity scales with the rms velocity (Krauss and Boning 1987;Brink et al 1991;Zhang et al 2001). Thus, in the future remains to determine what are the dynamical regimes that make the constant-T rule regionally applicable.…”

Section: Discussionmentioning

confidence: 99%

Eddy diffusivity derived from drifter data for dispersion model applications

et al. 2012

View full text Add to dashboard Cite

Ocean transport and dispersion processes are at the present time simulated using Lagrangian stochastic models coupled with Eulerian circulation models that are sup- plying analyses and forecasts of the ocean currents at unprecedented time and space resolution. Using the Lagrangian approach, each particle displacement is described by an average motion and a fluctuating part. The first one represents the advection associated with the Eulerian current field of the circulation models while the second one describes the sub-grid scale diffusion. The focus of this study is to quantify the sub-grid scale diffusion of the Lagrangian models written in terms of a horizontal eddy diffusivity. Using a large database of drifters released in different regions of the Mediterranean Sea, the Lagrangian sub-grid scale diffusion has been computed, by considering different regimes when averaging statistical quantities. In addition, the real drifters have been simulated using a trajectory model forced by OGCM currents, focusing on how the Lagrangian properties are reproduced by the simulated trajectories. © Springer-Verlag 2012

show abstract

Isopycnal Lagrangian statistics from the North Atlantic Current RAFOS float observations

Cited by 74 publications

References 37 publications

Arctic sea-ice diffusion from observed and simulated Lagrangian trajectories

Arctic sea-ice diffusion from observed and simulated Lagrangian trajectories

Eulerian and Lagrangian Statistics in the South China Sea as Deduced from Surface Drifters

Eddy diffusivity derived from drifter data for dispersion model applications

Contact Info

Product

Resources

About