Improved satellite altimetry in coastal systems: Case study of the Corsica Channel (Mediterranean Sea)

Vignudelli, Stefano; Cipollini, Paolo; Roblou, L.; Lyard, Florent; Gasparini, Gian Pietro; Manzella, G. M. R.; Astraldi, M.

doi:10.1029/2005gl022602

Cited by 110 publications

(87 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The magnitude of the geostrophic current is determined by (g/f )||∇ η ||, where g is the acceleration of gravity and f is the local Coriolis frequency). Note that the amplitudes of η from ROMS and Aviso are comparable in the domain, the larger discrepancies nearshore are at horizontal scales where Aviso is known to have limitations (Vignudelli et al 2005).…”

Section: Surface Circulationmentioning

confidence: 88%

Western boundary upwelling dynamics off Oman

et al. 2017

View full text Add to dashboard Cite

Despite its climatic and ecosystemic significance, the coastal upwelling that takes place off Oman is not well understood. A primitive-equation, regional model forced by climatological wind stress is used to investigate its dynamics and to compare it with the better-known Eastern Boundary Upwellings (EBUs). The solution compares favorably with existing observations, simulating well the seasonal cycles of thermal structure, surface circulation (mean and turbulent), and sea-surface temperature (SST). There is a 1.5-month lag between the maximum of the upwellingfavorable wind-stress-curl forcing and the oceanic response (minima in sea-surface height and SST), which we attribute to onshore-propagating Rossby waves. A southwestwardflowing undercurrent (opposite to the direction of the nearsurface flow) is also simulated with a core depth of 1000 m, much deeper than found in EBUs (150-200 m). An EKE budget reveals that, in contrast to EBUs, the upwelling jet is more prone to barotropic than baroclinic instability and the contribution of locally-generated instabilities to EKE is higher by an order of magnitude. Advection and redistribution of EKE by standing mesoscale features also play a significant role in EKE budget.

show abstract

Section: Surface Circulationmentioning

confidence: 88%

Western boundary upwelling dynamics off Oman

et al. 2017

View full text Add to dashboard Cite

show abstract

“…In the literature, the works that focus on sea-level variability and trends in the Mediterranean Sea by comparing tide-gauge and satellite altimetry data, usually consider a limited number of tide-gauge stations in sub-regional basins, using along-track satellite altimetry data (Vignudelli et al 2005;Pascual et al 2007;Fenoglio-Marc et al 2012;Birol and Delebecque 2014). In addition multi-mission gridded satellite altimetry data are used (Fenoglio-Marc 2002;Cazenave et al 2002;Pascual et al 2009), which in the version for the global ocean are not suitable for resolving the sea-level variability due to the meso-scale dynamics in the Mediterranean Sea (Robinson and Golnaraghi 1994;Robinson et al 2001;Pinardi et al 2015).…”

Section: Introductionmentioning

confidence: 99%

Sea-level variability in the Mediterranean Sea from altimetry and tide gauges

et al. 2016

View full text Add to dashboard Cite

mean sea-level and the coastal stations. From 1993 to 2012, the mean sea-level trend (2.44 ± 0.5 mm year −1 ) was found to be affected by the positive anomalies of 2010 and 2011, which were observed in all the cases analysed and were mainly distributed in the eastern part of the basin. Ensemble empirical mode decomposition showed that these events were related to the processes that have dominant periodicities of ∼10 years, and positive residual sea-level trend were generally observed in both data-sets. In terms of mean sea-level trends, a significant positive sea-level trend (>95 %) in the Mediterranean Sea was found on the basis of at least 15 years of data.

show abstract

“…Sea surface heights (SSHs) are the primary product of altimetry, which have greatly benefited studies of extensive scientific issues in geodesy, oceanography, geophysics and many other disciplines [1]. Despite the remarkable success of altimetry in the open ocean, which can provide SSHs with an accuracy of several centimeters, altimetry-derived SSHs in coastal zones are severely degraded due to inherent limitations of this technique [2][3][4]. The Altimeter emits pulse-limited radar signals and receives echoes from illuminated Earth surfaces in nadir.…”

Section: Introductionmentioning

confidence: 99%

Improving Jason-2 Sea Surface Heights within 10 km Offshore by Retracking Decontaminated Waveforms

et al. 2017

View full text Add to dashboard Cite

Abstract:It is widely believed that altimetry-derived sea surface heights (SSHs) in coastal zones are seriously degraded due to land contamination in altimeter waveforms from non-marine surfaces or due to inhomogeneous sea state conditions. Spurious peaks superimposed in radar waveforms adversely impact waveform retracking and hence require tailored algorithms to mitigate this problem. Here, we present an improved method to decontaminate coastal waveforms based on the waveform modification concept. SSHs within 10 km offshore are calculated from Jason-2 data by a 20% threshold retracker using decontaminated waveforms (DW-TR) and compared with those using original waveforms and modified waveforms in four study regions. We then compare our results with retracked SSHs in the sensor geophysical data record (SGDR) and with the state-of-the-art PISTACH (Prototype Innovant de Système de Traitement pour les Applications Côtières et l'Hydrologie) and ALES (Adaptive Leading Edge Subwaveform) products. Our result indicates that the DW-TR is the most robust retracker in the 0-10 km coastal band and provides consistent accuracy up to 1 km away from the coastline. In the four test regions, the DW-TR retracker outperforms other retrackers, with the smallest averaged standard deviations at 15 cm and 20 cm, as compared against the EGM08 (Earth Gravitational Model 2008) geoid model and tide gauge data, respectively. For the SGDR products, only the ICE retracker provides competitive SSHs for coastal applications. Subwaveform retrackers such as ICE3, RED3 and ALES perform well beyond 8 km offshore, but seriously degrade in the 0-8 km strip along the coast.

show abstract

Improved satellite altimetry in coastal systems: Case study of the Corsica Channel (Mediterranean Sea)

Cited by 110 publications

References 13 publications

Western boundary upwelling dynamics off Oman

Western boundary upwelling dynamics off Oman

Sea-level variability in the Mediterranean Sea from altimetry and tide gauges

Improving Jason-2 Sea Surface Heights within 10 km Offshore by Retracking Decontaminated Waveforms

Contact Info

Product

Resources

About