TY - JOUR
T1 - Enduring Lagrangian coherence of a Loop Current ring assessed using independent observations
AU - Beron-Vera, Francisco J.
AU - Olascoaga, María J.
AU - Wang, Yan
AU - Triñanes, Joaquín
AU - Pérez-Brunius, Paula
N1 - Funding Information:
The altimeter products were produced by SSALTO/DUCAS and distributed by AVISO with support from CNES (http://www.aviso.oceanobs). The ocean color products were produced and distributed by NASA OBPG. The surface drifters were deployed as part of Horizon Marine Inc.‘s EddyWatch program. The data have been provided as a part of a data exchange agreement between Horizon Marine Inc. and PEMEX under CICESE–PEMEX SAP contracts 428217896, 428218855, and 428229851. The quality control and post-processing of these data were carried out by Paula Garca and Argelia Ronquillo. The NCOM simulation was produced at the Naval Research Laboratory and can be obtained from the Gulf of Mexico Research Initiative Information & Data Cooperative (GRIIDC) at https://data.gulfresearchinitiative.org (dx.doi.org/10.7266/N7FQ9TJ6, dx.doi.org/10.7266/ N76Q1V5G, and dx.doi.org/ 10.7266/N72Z13F4). This research was made possible in part by a grant from the Gulf of Mexico Research Initiative (MJO, FJBV, and YW); SENER–CONACyT grant 201441 (MJO, FJBV, PPB) as part of the Consorcio de Investigación del Golfo de México (CIGoM); and NOAA/AOML and UM/CIMAS (JT).
Publisher Copyright:
© 2018, The Author(s).
PY - 2018/12/1
Y1 - 2018/12/1
N2 - Ocean flows are routinely inferred from low-resolution satellite altimetry measurements of sea surface height assuming a geostrophic balance. Recent nonlinear dynamical systems techniques have revealed that surface currents derived from altimetry can support mesoscale eddies with material boundaries that do not filament for many months, thereby representing effective transport mechanisms. However, the long-range Lagrangian coherence assessed for mesoscale eddy boundaries detected from altimetry is constrained by the impossibility of current altimeters to resolve ageostrophic submesoscale motions. These may act to prevent Lagrangian coherence from manifesting in the rigorous form described by the nonlinear dynamical systems theories. Here we use a combination of satellite ocean color and surface drifter trajectory data, rarely available simultaneously over an extended period of time, to provide observational evidence for the enduring Lagrangian coherence of a Loop Current ring detected from altimetry. We also seek indications of this behavior in the flow produced by a data-assimilative system which demonstrated ability to reproduce observed relative dispersion statistics down into the marginally submesoscale range. However, the simulated flow, total surface and subsurface or subsampled emulating altimetry, is not found to support the long-lasting Lagrangian coherence that characterizes the observed ring. This highlights the importance of the Lagrangian metrics produced by the nonlinear dynamical systems tools employed here in assessing model performance.
AB - Ocean flows are routinely inferred from low-resolution satellite altimetry measurements of sea surface height assuming a geostrophic balance. Recent nonlinear dynamical systems techniques have revealed that surface currents derived from altimetry can support mesoscale eddies with material boundaries that do not filament for many months, thereby representing effective transport mechanisms. However, the long-range Lagrangian coherence assessed for mesoscale eddy boundaries detected from altimetry is constrained by the impossibility of current altimeters to resolve ageostrophic submesoscale motions. These may act to prevent Lagrangian coherence from manifesting in the rigorous form described by the nonlinear dynamical systems theories. Here we use a combination of satellite ocean color and surface drifter trajectory data, rarely available simultaneously over an extended period of time, to provide observational evidence for the enduring Lagrangian coherence of a Loop Current ring detected from altimetry. We also seek indications of this behavior in the flow produced by a data-assimilative system which demonstrated ability to reproduce observed relative dispersion statistics down into the marginally submesoscale range. However, the simulated flow, total surface and subsurface or subsampled emulating altimetry, is not found to support the long-lasting Lagrangian coherence that characterizes the observed ring. This highlights the importance of the Lagrangian metrics produced by the nonlinear dynamical systems tools employed here in assessing model performance.
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U2 - 10.1038/s41598-018-29582-5
DO - 10.1038/s41598-018-29582-5
M3 - Article
C2 - 30050052
AN - SCOPUS:85050685478
VL - 8
JO - Scientific Reports
JF - Scientific Reports
SN - 2045-2322
IS - 1
M1 - 11275
ER -