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Zoltan Szuts

Senior Oceanographer





Department Affiliation

Ocean Physics


B.A. Biology, Oberlin College, 2001

M.S. Oceanography, University of Washington, 2004

Ph.D. Oceanography, University of Washington, 2008


2000-present and while at APL-UW

Salinity transport in the Florida Straits

Szuts, Z.B., and C. Meinen, "Salinity transport in the Florida Straits," J. Atmos. Oceanic Technol., 30, 971-983, doi:10.1175/JTECH-D-12-00133.1, 2013.

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1 May 2013

A submarine cable across the Florida Straits yields a time series of volume and temperature transports using previously determined calibrations, and here a calibration is defined for salinity transport using data not yet compared to the cable. Since 2001, 32 transects were collected with conductivity-temperature-depth (CTDs) sensors and lowered acoustic Doppler current profilers (LADCPs). Calibrations for volume and temperature transports using CTD/LADCP data are consistent with previous studies. A salinity calibration is obtained by regressing salinity transport against volume transport, where salinity transport is calculated relative to the basin-averaged salinity at 26°N (Sref = 35.156 psu). On average, the transect-derived salinity transport is 33.0 Sv psu (1 Sv ≡ 106 m3 s-1), has a standard deviation of 2.8 Sv psu, and has a 90th percentile range of 29.1–37.4 Sv psu. The cable-derived salinity transport has a root-mean-square error of 2.2 Sv psu compared to the CTD/LADCP transects. Inherent spatial fluctuations and their covariability in the Florida Straits are responsible for noise in the calibrations and for slight increases in accuracy from salinity to temperature to volume calibrations. Salinity fluctuations are strongest in middepth waters of intermediate salinity, where velocity is neither particularily fast nor variable. In contrast, temperature is highly stratified and warm near-surface waters coincide with fast and variable velocities. Temperature additionally exhibits seasonality near the surface, whereas no robust seasonality is found for salinity or velocity. Temperature and salinity transports are largely driven by volume transport, which in turn, because of a large average electrical conductivity, is closely related to the conductivity-weighted velocity that generates the cable-measured voltage.

Vertically averaged velocities in the North Atlantic Current from field trials of a Lagrangian electric-field float

Szuts, Z.B., and T.B. Sanford, "Vertically averaged velocities in the North Atlantic Current from field trials of a Lagrangian electric-field float," Deep Sea Res. II, 85, 210-219, doi:10.1016/j.dsr2.2012.07.022, 2013.

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1 Jan 2013

A subsurface Lagrangian float that utilizes motional induction to calculate vertically averaged velocities was tested in the North Atlantic Current (NAC), taking advantage of existing cruises and infrastructure. The Electric Field Float (EFF) is a RAFOS float with horizontal electrodes that measures its own velocity by RAFOS tracking and calculates vertically averaged velocities when merged with the electrode system. The observations showed depth-averaged velocities that were fast in the core of the NAC (0.6 – 0.9 m s-1) and moderate in adjacent recirculations and eddies (0.3 – 0.4 m s-1). A float at 850 dbar moved at close to the depth-averaged velocity, while shallower floats followed surface intensified flow on top of the depth-averaged motion. Integral time scales of depth-averaged velocity (1.3 – 1.6 ± 0.4 d) are slightly shorter than time scales of float velocity (1.6 – 2.0 ± 0.3 d), while integral length scales of depth-averaged water velocity (35 ± 10 km for u, 18 ± 6 km for v) are slightly shorter than length scales of float motion (53 ± 12 km for u, 28 ± 6 km for v). Velocity spectra of depth-averaged velocity show significant variance at inertial periods. Quantitative and qualitative validation with multiple independent data sets confirms the accuracy of the instrument and sampling strategy in the NAC, advancing the limited observational knowledge of depth-averaged circulation in subpolar regions.

A vertical-mode decomposition to investigate low-frequency internal motion across the Atlantic at 26°N

Szuts, Z.B., J.R. Blundell, M.P. Chidichimo, and J. Marotzke, "A vertical-mode decomposition to investigate low-frequency internal motion across the Atlantic at 26°N," Ocean Sci., 8, 345-367. doi:10.5194/os-8-345-2012, 2012.

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7 Jun 2012

Hydrographic data from full-depth moorings maintained by the Rapid/-MOCHA project and spanning the Atlantic at 26° N are decomposed into vertical modes in order to give a dynamical framework for interpreting the observed fluctuations. Vertical modes at each mooring are fit to pressure perturbations using a Gauss-Markov inversion. Away from boundaries, the vertical structure is almost entirely described by the first baroclinic mode, as confirmed by high correlation between the original signal and reconstructions using only the first baroclinic mode. These first baroclinic motions are also highly coherent with altimetric sea surface height (SSH). Within a Rossby radius (45 km) of the western and eastern boundaries, however, the decomposition contains significant variance at higher modes, and there is a corresponding decrease in the agreement between SSH and either the original signal or the first baroclinic mode reconstruction. Compared to the full transport signal, transport fluctuations described by the first baroclinic mode represent <25 km of the variance within 10 km of the western boundary, in contrast to 60 km at other locations. This decrease occurs within a Rossby radius of the western boundary. At the eastern boundary, a linear combination of many baroclinic modes is required to explain the observed vertical density profile of the seasonal cycle, a result that is consistent with an oceanic response to wind-forcing being trapped to the eastern boundary.

More Publications

Acoustics Air-Sea Interaction & Remote Sensing Center for Environmental & Information Systems Center for Industrial & Medical Ultrasound Electronic & Photonic Systems Ocean Engineering Ocean Physics Polar Science Center