The Experts below are selected from a list of 5868 Experts worldwide ranked by ideXlab platform
Xavier Bertin - One of the best experts on this subject based on the ideXlab platform.
-
Monitoring the topography of a dynamic Tidal Inlet using UAV imagery
Remote Sensing, 2016Co-Authors: Nathalie Long, Bastien Millescamps, Frédéric Pouget, Benoit Guillot, Xavier BertinAbstract:Unmanned Aerial Vehicles (UAVs) are being increasingly used to monitor topographic changes in coastal areas. Compared to Light Detection And Ranging (LiDAR) data or Terrestrial Laser Scanning data, this solution is low-cost and easy to use, while allowing the production of a Digital Surface Model (DSM) with a similar accuracy. Three campaigns were carried out within a three-month period at a lagoon-Inlet system (Bonne-Anse Bay, La Palmyre, France), with a flying wing (eBee) combined with a digital camera. Ground Control Points (GCPs), surveyed by the Global Navigation Satellite System (GNSS) and post-processed by differential correction, allowed georeferencing DSMs. Using a photogrammetry process (Structure From Motion algorithm), DSMs and orthomosaics were produced. The DSM accuracy was assessed against the ellipsoidal height of a GNSS profile and Independent Control Points (ICPs) and the root mean square discrepancies were about 10 and 17 cm, respectively. Compared to traditional topographic surveys, this solution allows the accurate representation of bedforms with a wavelength of the order of 1 m and a height of 0.1 m. Finally, changes identified between both main campaigns revealed erosion/accretion areas and the progradation of a sandspit. These results open new perspectives to validate detailed morphological predictions or to parameterize bottom friction in coastal numerical models.
-
morphological evolution of an ephemeral Tidal Inlet from opening to closure the albufeira Inlet portugal
Continental Shelf Research, 2014Co-Authors: A B Fortunato, Xavier Bertin, Guillaume Dodet, Alphonse Nahon, Ana Rita Pires, M C Freitas, Nicolas Bruneau, Alberto Azevedo, Pedro Benevides, Cesar AndradeAbstract:Abstract Like other similar coastal systems, the Albufeira lagoon is artificially opened every year to promote water renewal and closes naturally within a few months. The evolution of the Albufeira Lagoon Inlet from its opening in April 2010 to its closure 8 months later is qualitatively and quantitatively analyzed through a combination of monthly field surveys and the application of a process-based morphodynamic model. Field data alone would not cover the whole space–time domain of the morphology of the Inlet during its life time, whereas the morphodynamic model alone cannot reliably simulate the morphological development. Using a nudging technique introduced herein, this problem is overcome and a reliable and complete data set is generated for describing the morphological development of the Tidal Inlet. The new technique is shown to be a good alternative to extensive model calibration, as it can drastically improve the model performance. Results reveal that the lagoon imported sediments during its life span. However, the whole system (lagoon plus littoral barrier) actually lost sediments to the sea. This behavior is partly attributed to the modulation of Tidal asymmetry by the spring–neap cycle, which reduces flood dominance on spring tides. Results also allowed the assessment of the relationship between the spring Tidal prism and the cross-section of Tidal Inlets (the PA relationship). While this relationship is well established from empirical, theoretical and numerical evidences, its validity in Inlets that are small or away from equilibrium was unclear. Results for the Albufeira lagoon reveal an excellent match between the new data and the empirical PA relationship derived for larger Inlets and equilibrium conditions, supporting the validity of the relationship beyond its original scope.
-
wave current interactions in a wave dominated Tidal Inlet
Journal of Geophysical Research, 2013Co-Authors: Guillaume Dodet, Xavier Bertin, A B Fortunato, Alphonse Nahon, Nicolas Bruneau, Aron RolandAbstract:[1] Wave-current interactions play a major role in the dynamics of shallow Tidal Inlets. This study investigates these interactions at a natural Inlet, with a strong focus on current-induced changes on wave propagation. The analysis of hydrodynamic data collected at the Albufeira lagoon, Portugal, revealed spatiotemporal variations of water levels and wave heights along the Inlet, attributed to wave-current interaction processes. We compared the simulations of a coupled wave-circulation modeling system, computed with and without waves, and propagated with and without current feedback. The wave-induced setup inside the lagoon represented 7%–15% of the offshore significant wave height. The accuracy of the wave's predictions improved when current feedback was included. During ebb, the currents increased the wave height at the mouth of the Inlet (up to 20%) and decreased the wave height in the Inlet (up to 40%), due to current-induced refraction, steepness dissipation, and partial blocking. During flood, the currents decreased the wave height in the Inlet (up to 10%) and increased the wave height at the exterior parts of the ebb shoal (up to 10%), due to current-induced refraction. These effects significantly attenuate seaward sediment fluxes during ebb and contribute to the sediment accretion in the Inlet.
-
future evolution of a Tidal Inlet due to changes in wave climate sea level and lagoon morphology obidos lagoon portugal
Continental Shelf Research, 2011Co-Authors: Nicolas Bruneau, Guillaume Dodet, A B Fortunato, P Freire, Anabela Oliveira, Xavier BertinAbstract:Abstract Tidal Inlets are extremely dynamic, as a result of an often delicate balance between the effects of tides, waves and other forcings. Since the morphology of these Inlets can affect navigation, water quality and ecosystem dynamics, there is a clear need to anticipate their evolution in order to promote adequate management decisions. Over decadal time scales, the position and size of Tidal Inlets are expected to evolve with the conditions that affect them, for instance as a result of climate change. A process-based morphodynamic modeling system is validated and used to analyze the effects of sea level rise, an expected shift in the wave direction and the reduction of the upper lagoon surface area by sedimentation on a small Tidal Inlet (Obidos lagoon, Portugal). A new approach to define yearly wave regimes is first developed, which includes a seasonal behavior, random inter-annual variability and the possibility to extrapolate trends. Once validated, this approach is used to produce yearly time series of wave spectra for the present and for the end of the 21st century, considering the local rotation trends computed using hindcast results for the past 57 years. Predictions of the mean sea level for 2100 are based on previous studies, while the bathymetry of the upper lagoon for the same year is obtained by extrapolation of past trends. Results show, and data confirm, that the Obidos lagoon Inlet has three stable configurations, largely determined by the inter-annual variations in the wave characteristics. Both sea level rise and the reduction of the lagoon surface area will promote the accretion of the Inlet. In contrast, the predicted rotation of the wave regime, within foreseeable limits, will have a negligible impact on the Inlet morphology.
-
modelling of the gold coast seaway Tidal Inlet australia
Journal of Coastal Research, 2007Co-Authors: Gilles Sennes, Xavier Bertin, Bruno Castelle, Hamid Mirfenderesk, Rodger Benson TomlinsonAbstract:SENNES, G., CASTELLE, B., BERTIN, X., MIRFENDERESK, H. AND TOMLINSON, R.B., 2007. Modelling of the Gold Coast Seaway Tidal Inlet, Australia. Journal of Coastal Research, SI 50 (Proceedings of the 9th International Coastal Symposium), 1086 – 1091. Gold Coast, Australia, ISSN 0749.0208 The Seaway entrance is a Tidal Inlet located on the Gold Coast (Queensland, Australia). Before the 80s, the entrance was highly variable in terms of Inlet location and sand bar characteristics. The Seaway stabilisation with two training walls combined with an artificial sand bypassing system were completed in 1986 with the aims of fixing the entrance, maintaining a safe navigable channel, preventing shoreline erosion to the north and a buildup of sand to the south. Despite these training works, the dynamics of the Seaway is still poorly understood: channel infilling problems and navigation issues remain. For these reasons, the present study aims to develop a comprehensive model of the entrance to be used for further dredging and training work issues. The present investigation is carried out in two stages. The first stage is based on historic aerial photograph analysis of the Seaway before training works. It shows that the mouth was periodically driven northward by the longshore drift, with an average cycle time of 10 years. The second stage is based on numerical modelling after training works. Refined Delft3D modelling is undertaken with a 2DH approach on the Seaway area, taking into account the training walls and the sand bypassing system. This local model is coupled with MIKE21 implemented on a regional scale to provide accurate tide and flow forcing at the boundaries. After calibration, the analysis of flow patterns shows that the Gold Coast Seaway is ebb-dominated and that the more intense flow velocities are observed in the northern channel. Morphological evolution of the Inlet is also investigated with a qualitative approach. Results indicate the pathways and rate of the sand movement within the Tidal Inlet in its current configuration and provide information about a planned 400 m extension of the southern training wall. A significant calibration work, involving sediment transport and bathymetry measurement, is required for the model to be used as a comprehensive tool for further dredging and dumping strategies within the entrance.
Robert T. Guza - One of the best experts on this subject based on the ideXlab platform.
-
Observations and Modeling of a Tidal Inlet Dye Tracer Plume
Journal of Geophysical Research, 2016Co-Authors: Falk Feddersen, Robert T. Guza, Dylan Winters, Britt Raubenheimer, Maitane Olabarrieta, Steve ElgarAbstract:A 9 km long tracer plume was created by continuously releasing Rhodamine WT dye for 2.2 h during ebb tide within the southern edge of the main Tidal channel at New River Inlet, NC on 7 May 2012, with highly obliquely incident waves and alongshore winds. Over 6 h from release, COAWST (coupled ROMS and SWAN, including wave, wind, and Tidal forcing) modeled dye compares well with (aerial hyperspectral and in situ) observed dye concentration. Dye first was transported rapidly seaward along the main channel and partially advected across the ebb-Tidal shoal until reaching the offshore edge of the shoal. Dye did not eject offshore in an ebb-Tidal jet because the obliquely incident breaking waves retarded the Inlet-mouth ebb-Tidal flow and forced currents along the ebb shoal. The dye plume largely was confined to
-
observations and modeling of a Tidal Inlet dye tracer plume
Journal of Geophysical Research, 2016Co-Authors: Falk Fedderse, Robert T. Guza, Dyla Winters, I Raubenheime, Maitane Olabarrieta, Steve ElgaAbstract:A 9 km long tracer plume was created by continuously releasing Rhodamine WT dye for 2.2 h during ebb tide within the southern edge of the main Tidal channel at New River Inlet, NC on 7 May 2012, with highly obliquely incident waves and alongshore winds. Over 6 h from release, COAWST (coupled ROMS and SWAN, including wave, wind, and Tidal forcing) modeled dye compares well with (aerial hyperspectral and in situ) observed dye concentration. Dye first was transported rapidly seaward along the main channel and partially advected across the ebb-Tidal shoal until reaching the offshore edge of the shoal. Dye did not eject offshore in an ebb-Tidal jet because the obliquely incident breaking waves retarded the Inlet-mouth ebb-Tidal flow and forced currents along the ebb shoal. The dye plume largely was confined to <4 m depth. Dye was then transported downcoast in the narrow (few 100 m wide) surfzone of the beach bordering the Inlet at 0.3 m s−1 driven by wave breaking. Over 6 h, the dye plume is not significantly affected by buoyancy. Observed dye mass balances close indicating all released dye is accounted for. Modeled and observed dye behaviors are qualitatively similar. The model simulates well the evolution of the dye center of mass, lateral spreading, surface area, and maximum concentration, as well as regional (“Inlet” and “ocean”) dye mass balances. This indicates that the model represents well the dynamics of the ebb-Tidal dye plume. Details of the dye transport pathways across the ebb shoal are modeled poorly perhaps owing to low-resolution and smoothed model bathymetry. Wave forcing effects have a large impact on the dye transport.
-
observed and modeled drifters at a Tidal Inlet
Journal of Geophysical Research, 2015Co-Authors: Matthew S Spydell, Robert T. Guza, Falk Feddersen, Britt Raubenheimer, Maitane Olabarrieta, Jialin Chen, Steve ElgarAbstract:Material transport and dispersion near the mouth of a Tidal Inlet (New River Inlet, NC) are investigated using GPS-tracked drifters and numerical models. For ebb tide releases, velocities are largest (>1 m s−1) in two approximately 30 m wide channels that bisect the 1–3 m deep ebb shoal. In the channels, drifter and subsurface current meter velocities are similar, consistent with strong vertical mixing and 2-D hydrodynamics. Drifters were preferentially entrained in the channelized jets where drifter cluster lateral spreading rates μin were small ( μin≈0.5 m2 s−1). At the seaward edge of the ebb shoal, jet velocities decrease linearly with distance (to ≤0.2 m s−1, about 1 km from shore), and cluster spreading rates are larger with μout≈3 m2 s−1. Although the models COAWST and NearCom generally reproduce the observed trajectory directions, certain observed drifter properties are poorly modeled. For example, modeled mean drifter velocities are smaller than observed, and upon exiting the Inlet, observed drifters turn north more than modeled drifters. The model simulations do reproduce qualitatively the spreading rates observed in the inner Inlet, the flow deceleration, and the increase in μout observed in the outer Inlet. However, model spreading rates increase only to μout<1 m2 s−1. Smaller modeled than observed μout may result from using unstratified models. Noncoincident (in space) observations show evidence of a buoyant plume ( Δρ=1 kg m−3) in the outer Inlet, likely affecting drifter lateral spreading. Generally, drifter-based model performance is good within the Inlet channels where Tidal currents are strongest, whereas model-data differences are significant farther offshore.
-
Lagrangian Tracer Transport and Dispersion in Shallow Tidal Inlets & River Mouths
2011Co-Authors: Robert T. Guza, Falk FeddersenAbstract:Abstract : Long-term objectives are developing and field testing numerical models of shallow water breaking waves and wave-driven processes including mixing, currents, and transport and dispersion of tracers. Calibrated models will provide improved prediction of the fate of tracers (e.g. pollution, fine sediment, chemicals) in very shallow water. Objectives during the past year included continued analysis of existing data sets, and extending our existing field capability in preparation for participation in the Tidal Inlet/river mouth DRI.
Falk Feddersen - One of the best experts on this subject based on the ideXlab platform.
-
Observations and Modeling of a Tidal Inlet Dye Tracer Plume
Journal of Geophysical Research, 2016Co-Authors: Falk Feddersen, Robert T. Guza, Dylan Winters, Britt Raubenheimer, Maitane Olabarrieta, Steve ElgarAbstract:A 9 km long tracer plume was created by continuously releasing Rhodamine WT dye for 2.2 h during ebb tide within the southern edge of the main Tidal channel at New River Inlet, NC on 7 May 2012, with highly obliquely incident waves and alongshore winds. Over 6 h from release, COAWST (coupled ROMS and SWAN, including wave, wind, and Tidal forcing) modeled dye compares well with (aerial hyperspectral and in situ) observed dye concentration. Dye first was transported rapidly seaward along the main channel and partially advected across the ebb-Tidal shoal until reaching the offshore edge of the shoal. Dye did not eject offshore in an ebb-Tidal jet because the obliquely incident breaking waves retarded the Inlet-mouth ebb-Tidal flow and forced currents along the ebb shoal. The dye plume largely was confined to
-
observed and modeled drifters at a Tidal Inlet
Journal of Geophysical Research, 2015Co-Authors: Matthew S Spydell, Robert T. Guza, Falk Feddersen, Britt Raubenheimer, Maitane Olabarrieta, Jialin Chen, Steve ElgarAbstract:Material transport and dispersion near the mouth of a Tidal Inlet (New River Inlet, NC) are investigated using GPS-tracked drifters and numerical models. For ebb tide releases, velocities are largest (>1 m s−1) in two approximately 30 m wide channels that bisect the 1–3 m deep ebb shoal. In the channels, drifter and subsurface current meter velocities are similar, consistent with strong vertical mixing and 2-D hydrodynamics. Drifters were preferentially entrained in the channelized jets where drifter cluster lateral spreading rates μin were small ( μin≈0.5 m2 s−1). At the seaward edge of the ebb shoal, jet velocities decrease linearly with distance (to ≤0.2 m s−1, about 1 km from shore), and cluster spreading rates are larger with μout≈3 m2 s−1. Although the models COAWST and NearCom generally reproduce the observed trajectory directions, certain observed drifter properties are poorly modeled. For example, modeled mean drifter velocities are smaller than observed, and upon exiting the Inlet, observed drifters turn north more than modeled drifters. The model simulations do reproduce qualitatively the spreading rates observed in the inner Inlet, the flow deceleration, and the increase in μout observed in the outer Inlet. However, model spreading rates increase only to μout<1 m2 s−1. Smaller modeled than observed μout may result from using unstratified models. Noncoincident (in space) observations show evidence of a buoyant plume ( Δρ=1 kg m−3) in the outer Inlet, likely affecting drifter lateral spreading. Generally, drifter-based model performance is good within the Inlet channels where Tidal currents are strongest, whereas model-data differences are significant farther offshore.
-
Lagrangian Tracer Transport and Dispersion in Shallow Tidal Inlets & River Mouths
2011Co-Authors: Robert T. Guza, Falk FeddersenAbstract:Abstract : Long-term objectives are developing and field testing numerical models of shallow water breaking waves and wave-driven processes including mixing, currents, and transport and dispersion of tracers. Calibrated models will provide improved prediction of the fate of tracers (e.g. pollution, fine sediment, chemicals) in very shallow water. Objectives during the past year included continued analysis of existing data sets, and extending our existing field capability in preparation for participation in the Tidal Inlet/river mouth DRI.
Steve Elgar - One of the best experts on this subject based on the ideXlab platform.
-
Observations and Modeling of a Tidal Inlet Dye Tracer Plume
Journal of Geophysical Research, 2016Co-Authors: Falk Feddersen, Robert T. Guza, Dylan Winters, Britt Raubenheimer, Maitane Olabarrieta, Steve ElgarAbstract:A 9 km long tracer plume was created by continuously releasing Rhodamine WT dye for 2.2 h during ebb tide within the southern edge of the main Tidal channel at New River Inlet, NC on 7 May 2012, with highly obliquely incident waves and alongshore winds. Over 6 h from release, COAWST (coupled ROMS and SWAN, including wave, wind, and Tidal forcing) modeled dye compares well with (aerial hyperspectral and in situ) observed dye concentration. Dye first was transported rapidly seaward along the main channel and partially advected across the ebb-Tidal shoal until reaching the offshore edge of the shoal. Dye did not eject offshore in an ebb-Tidal jet because the obliquely incident breaking waves retarded the Inlet-mouth ebb-Tidal flow and forced currents along the ebb shoal. The dye plume largely was confined to
-
observed and modeled drifters at a Tidal Inlet
Journal of Geophysical Research, 2015Co-Authors: Matthew S Spydell, Robert T. Guza, Falk Feddersen, Britt Raubenheimer, Maitane Olabarrieta, Jialin Chen, Steve ElgarAbstract:Material transport and dispersion near the mouth of a Tidal Inlet (New River Inlet, NC) are investigated using GPS-tracked drifters and numerical models. For ebb tide releases, velocities are largest (>1 m s−1) in two approximately 30 m wide channels that bisect the 1–3 m deep ebb shoal. In the channels, drifter and subsurface current meter velocities are similar, consistent with strong vertical mixing and 2-D hydrodynamics. Drifters were preferentially entrained in the channelized jets where drifter cluster lateral spreading rates μin were small ( μin≈0.5 m2 s−1). At the seaward edge of the ebb shoal, jet velocities decrease linearly with distance (to ≤0.2 m s−1, about 1 km from shore), and cluster spreading rates are larger with μout≈3 m2 s−1. Although the models COAWST and NearCom generally reproduce the observed trajectory directions, certain observed drifter properties are poorly modeled. For example, modeled mean drifter velocities are smaller than observed, and upon exiting the Inlet, observed drifters turn north more than modeled drifters. The model simulations do reproduce qualitatively the spreading rates observed in the inner Inlet, the flow deceleration, and the increase in μout observed in the outer Inlet. However, model spreading rates increase only to μout<1 m2 s−1. Smaller modeled than observed μout may result from using unstratified models. Noncoincident (in space) observations show evidence of a buoyant plume ( Δρ=1 kg m−3) in the outer Inlet, likely affecting drifter lateral spreading. Generally, drifter-based model performance is good within the Inlet channels where Tidal currents are strongest, whereas model-data differences are significant farther offshore.
-
radar remote sensing estimates of waves and wave forcing at a Tidal Inlet
Journal of Atmospheric and Oceanic Technology, 2015Co-Authors: Guillermo Diaz M Mendez, Britt Raubenheimer, Steve Elgar, Merrick C Haller, David A HoneggerAbstract:ThetimeandspacevariabilityofwavetransformationthroughaTidalInletis investigatedwithradarremote sensing. The frequency of wave breaking and the net wave breaking dissipation at high spatial resolution is estimated using image sequences acquired with a land-based X-band marine radar. Using the radar intensity data, transformed to normalized radar cross section s 0 , the temporal and spatial distributions of wave breaking are identified using a threshold developed via the data probability density function. In addition, the Inlet bathymetry is determined via depth inversion of the radar-derived frequencies and wavenumbers of the surface waves using a preexisting algorithm (cBathy). Wave height transformation is calculated through the 1D cross-shore energy flux equation incorporating the radar-estimated breaking distribution and bathymetry.Theaccuracyofthemethodologyistestedbycomparisonwithinsituwaveheightobservationsover a9-dayperiod,obtainingcorrelationvaluesR50.68to0.96,androot-mean-squareerrorsfrom0.05to0.19m. Predicted wave forcing, computed as the along-Inlet gradient of the cross-shore radiation stress ›Sxx/›x was onshore during high-wave conditions, in good agreement (R 5 0.95) with observations.
Arnoldo Vallelevinson - One of the best experts on this subject based on the ideXlab platform.
-
overtide generation by wind induced waves in a Tidal Inlet of sw france
Continental Shelf Research, 2019Co-Authors: Aldo Sottolichio, Fernanda P S Nascimento, Arnoldo Vallelevinson, Nadia SenechalAbstract:Abstract Quarter-diurnal Tidal constituents are linked to Tidal asymmetries and play a role in the morphodynamic evolution of Inlets, estuaries and lagoons. A two-year non-continuous dataset of current velocities and waves was used to improve understanding on the generation of quarter-diurnal harmonics. Data analysis provides evidence for the generation of quarter-diurnal harmonics by wind-induced waves. Data were collected at the entrance to the Arcachon Lagoon, a mixed-energy Tidal Inlet in Southwest France. Temporal variability of the quarter-diurnal Tidal current was identified through wavelet analysis of the main velocity component (alongshore velocity). Quarter-diurnal velocity amplitudes, bottom and wave stresses, and significant wave height suggested a linkage between quarter-diurnal amplification and wave action. Both significant wave height and wave stress were coherent with quarter-diurnal current amplitudes at synoptic frequencies, most markedly in winter months of both years observed. These coherences corroborated the hypothesis that wind-induced waves enhance bottom stresses that can generate and augment quarter-diurnal currents in this region.
-
Tidal and subTidal exchange flows at an Inlet of the wadden sea
Estuarine Coastal and Shelf Science, 2018Co-Authors: Arnoldo Vallelevinson, Emil V Stanev, Thomas H BadewienAbstract:Abstract Observations of underway velocity profiles during complete spring and neap Tidal cycles were used to determine whether the spatial structures of Tidal and subTidal flows at a Tidal Inlet in a multiple-Inlet embayment are consistent with those observed at single-Inlet embayments. Measurements were obtained at the Otzumer Balje, one of the multiple Inlets among the East Frisian Islands of the Wadden Sea. The 1.5 km-wide Inlet displayed a bathymetric profile consisting of a channel ∼15 m deep flanked by
-
influence of two tropical storms on the residual flow in a subtropical Tidal Inlet
Estuaries and Coasts, 2013Co-Authors: Arnoldo Vallelevinson, Amy F Waterhouse, Bilge Tutak, Peter Y ShengAbstract:The mechanisms responsible for the modulation of laterally sheared non-Tidal (residual) exchange flow in a subtropical Inlet, with special emphasis on tropical storm influence, are studied using a combination of current velocity profiles and hydrographic and meteorological data. The mouth of the Inlet, St. Augustine Inlet in northeast Florida, is characterized by a 15-m-deep channel flanked by shoals (<6 m deep). Residual flows across the Inlet mouth were laterally sheared with inflow in the channel and outflow over the shoals. This pattern persisted during four separate semi-diurnal Tidal cycle surveys effected over 3 years. During spring tides, residual exchange flows intensified relative to neap tides. Residual inflow in the channel only reversed immediately after tropical storms because of their extreme winds and major temporal changes in water level. After the residual flow reversed in the channel, along-channel baroclinicity drove gravitational circulation that persisted for 4.5 days and was enhanced by offshore winds. A depth-averaged along-basin momentum budget highlighted the importance of bottom friction to help balance the barotropic pressure gradient. The rest of the momentum budget was likely provided by advective terms. During and after tropical storms, accelerations from wind stress and baroclinic pressure gradients also became influential in the along-basin momentum budget.
-
transverse structure of subTidal flow in a weakly stratified subtropical Tidal Inlet
Continental Shelf Research, 2010Co-Authors: Amy F Waterhouse, Arnoldo VallelevinsonAbstract:The transverse structure of exchange flows and lateral flows as well as their relationship to the subTidal variability are investigated in a subtropical Inlet, Ponce de Leon Inlet, Florida. Two surveys were executed during different phases of the Tidal month to determine the spatial structure of subTidal exchange flows. Data from fixed moorings were used to depict the temporal variability of the spatial structure established in the surveys. The data suggested a Tidally rectified pattern of net outflow in the channel and inflow over shoals with a negligible influence of streamwise baroclinic pressure gradients on the dynamics and slight modifications due to the wind. Onshore winds strengthened net inflows but weakened net outflows, rarely reversing them, while offshore winds increased net outflows and weakened net inflows. Curvature effects were found to be important in modifying secondary circulations. Slight modifications to the secondary flows were also caused by stream-normal baroclinicity during one survey. Most important, the intensity of the exchange flows was modulated by tides, with the largest exchange flows developing in response to the strongest Tidal rectification of spring tides.