Transformation of wave height distribution

Thornton, Edward B.; Guza, R. T.

doi:10.1029/jc088ic10p05925

Cited by 746 publications

(594 citation statements)

References 27 publications

Supporting

Mentioning

574

Contrasting

Unclassified

Order By: Relevance

“…Also, overprediction of wave breaking dissipation by the analytical model is not surprising. The use of the bore dissipation formulation [Thornton and Guza, 1983] worked well for surf zone dissipation when weighted by a breaking wave height probability distribution that had been verified using surf zone data. It is not expected that the distribution would necessarily work well for greater depths where bottom-induced breaking seldom occurs.…”

Section: Dissipation Of Shoaling Swell: a Case Studymentioning

confidence: 99%

Airborne remote sensing applications to coastal wave research

Hwang¹,

Walsh²,

Krabill³

et al. 1998

J. Geophys. Res.

View full text Add to dashboard Cite

Abstract. Airborne sensors provide effective coverage of a broad region and are suitable for large-scale experiments. In this paper, two scanning sensors that use the direct ranging technique to measure surface wave displacement are described. On a NASA P-3 aircraft the sensors can complete one run across a 100-km continental shelf in 17 min. A case study is presented using radar-measured, two-dimensional surface topography to derive wave damping due to bottom friction. The results are in good agreement with an analytical model based on a quadratic formulation of bottom shear stress. This study demonstrates that remote sensing measurements can be used for rapid characterization of surface waves on the continental shelf and in coastal regions. Examples illustrated in this paper include the derivation of wavenumber spectra and estimation of the dissipation rate of shoaling ocean swell. IntroductionOcean wave research has placed emphasis either on the deep ocean to develop global wave modeling techniques or on the coastal waters to study wave effects on processes such as nearshore circulation and beach erosion. In terms of comprehensive and nearly simultaneous in situ measurements at a sufficient number of locations the continental shelf between deep water and the surf zone has been largely left out so that a critical gap obviously exists. For studying waves in the littoral environment the area of coverage reaches from the edge of the continental slope to the coastline. Because of the large expanse of the continental shelf (the shelf width along the East Coast of the United States is of the order of 100 km) the application of remote sensing for studying wave propagation on the continental shelf is an attractive option. With an airspeed of the order of 100 m/s, airborne sensors can provide very efficient two-dimensional surface wave measurements over a large oceanic area. For example, a NASA P-3 aircraft can cross the continental shelf's 100-km width near Duck, North Carolina, within 1000 s. Such broad-range coverage is impossible to achieve with in situ sensors. In this paper, the application of airborne remote sensing using scanning radar and scanning lidar is discussed. Section 2 describes the measurement principles of these remote sensing techniques and the relevant resolution issues. Section 3 presents examples of applications using spatial remote sensing data to study wave propagation and related phenomena in the coastal region. The spatial remote sensing data from the scanning radar are used to derive Remote Sensing by Radio and Optical RangingThe data analyzed in this paper were collected from a NASA P-3 aircraft using a scanning radar altimeter (SRA) and an airborne topographic mapper (ATM, a scanning lidar system).

show abstract

Section: Dissipation Of Shoaling Swell: a Case Studymentioning

confidence: 99%

Airborne remote sensing applications to coastal wave research

Hwang¹,

Walsh²,

Krabill³

et al. 1998

J. Geophys. Res.

View full text Add to dashboard Cite

show abstract

“…[17] The cross-shore distribution of physical wave parameters (wave energy, seabed orbital velocity, alongshore wave energy flux) for studying the influence of waves on the bottom sediments were calculated for the open coast sites following equations from Komar [1998] with the influence of breaking in the surf-zone modeled using the method presented by Thornton and Guza [1983]. The model was initialized using wave data over seven years (23 Sept. 2003-02 June 2010) from the Pukehina wave buoy located to the southeast of the study area (37.3812 S, 176.947 E) in 62 m water depth.…”

Section: Wave Parametersmentioning

confidence: 99%

Formation of magnetite‐enriched zones in and offshore of a mesotidal estuarine lagoon: An environmental magnetic study of Tauranga Harbour and Bay of Plenty, New Zealand

Badesab

Dobeneck

Bryan

et al. 2012

Geochem Geophys Geosyst

View full text Add to dashboard Cite

[1] Magnetic iron minerals are widespread and indicative sediment constituents in estuarine, coastal and shelf systems. We combine environmental magnetic, sedimentological and numerical methods to identify magnetite-enriched placer-like zones in a complex coastal system and delineate their formation mechanisms. Magnetic susceptibility and remanence measurements on 245 surficial sediment samples collected in and around Tauranga Harbour, the largest barrier-enclosed tidal estuary of New Zealand, reveal several discrete enrichment zones controlled by local hydrodynamic conditions. Active magnetite enrichment takes place in tidal channels, which feed into two coast-parallel nearshore magnetite-enriched belts centered at water depths of 6-10 m and 10-20 m. A close correlation between magnetite content and magnetic grain size was found, where higher susceptibility values are associated within coarser magnetic crystal sizes. Two key mechanisms for magnetite enrichment are identified. First, tide-induced residual currents primarily enable magnetite enrichment within the estuarine channel network. A coast-parallel, fine sand magnetite enrichment belt in water depths of less than 10 m along the barrier island has a strong decrease in magnetite ©2012. American Geophysical Union. All Rights Reserved.1 of 20 content away from the southern tidal inlet and is apparently related to active coast-parallel transport combined with mobilizing surf zone processes. A second, less pronounced, but more uniform magnetite enrichment belt at 10-20 m water depth is composed of non-mobile, medium-coarse-grained relict sands, which have been reworked during post-glacial sea level transgression. We demonstrate the potential of magnetic methods to reveal and differentiate coastal magnetite enrichment patterns and investigate their formative mechanisms.

show abstract

“…Given an arbitrary depth profile and offshore wave statistics, a simple wave transformation model [e.g., Thornton and Guza, 1983] can be used to predict the rms wave height over the entire profile. Thus it is possible to predict the values of o-, (via (5)) and y (via (7) Bagnold [1963] assumed that the mean normal stress exerted by the weight of the bed load is supported, on average, by the mean tangential stress.…”

Section: Sediment Transportmentioning

confidence: 99%

Morphologic properties derived from a simple cross‐shore sediment transport model

Plant¹,

Ruessink²,

Wijnberg³

2001

J. Geophys. Res.

View full text Add to dashboard Cite

Abstract. This paper builds on the now classical discussions by Bowen [1980] and Bailard [1981] on the applicability and implications of Bagnold's [1963] sediment transport model to nearshore profile modeling. We focus on the morphologic implications of both the strengths and weaknesses of Bagnold's model, isolating the transport terms that are well predicted (i.e., mean flow terms) from those that are not well predicted (i.e., transport due to correlations between flow and sediment load). We factor Bagnold's model into a dimensional transport magnitude and a nondimensional term. The nondimensional term describes the relative importance of transport due to undertow, gravity, and correlations between flow and sediment load. The transport magnitude largely determines the response time of nearshore profiles. For typical nearshore environments this response time was estimated to vary as a function of incident rms wave height (Hrms) from ----500 years (Hrm s "• 0.5 m) to 2 years (Hrm s '-" 3 m). The relative importance of competing transport mechanisms is shown to depend strongly on the relative wave height (defined as the ratio of the rms wave height to the local depth). Simplified nearshore transport parameterizations that are a function of this variable were derived and were interrogated for the existence and form of equilibrium profiles. Several differences from previously computed equilibrium profiles were noted. First, because the relative wave height saturates in natural surf zones, equilibrium profiles converge to a relatively flat profile near the shoreline. Second, under some situations a seaward sloping equilibrium profile may not exist. Third, the long response times combined with unknown stability of an equilibrium profile make it difficult to assess the physical connection between theoretical equilibrium profiles and profiles observed in nature. IntroductionAt present, accurate prediction of nearshore bathymetric change at all relevant scales is impossible. Part of the difficulty is that the relevant scales span a very broad range, from millimeters (individual sand grains) to kilometers (the cross-shore width of the surfzone) and tens of kilometers (alongshore extent of littoral cells). The largest spatial scales are particularly important because they contain the majority of the spatial and temporal variability of nearshore bathymetric change [Lippmann and Holman, 1990; Plant et al., 1999]. These are also the spatial and temporal scales that characterize human interactions with the coast. Unfortunately, the difficulty in modeling and prediction is acute at the largest scales, since evolution at this scale requires the integration over all smaller scales [Roelvink and BrOker, 1993].Ideally, the interaction between the large-scale morphology (e.g., surf zone sandbars or the cross-shore profile as a whole) and small-scale processes (e.g., wave-driven hydrodynamics and sediment transport) can be described in terms of param- The advantage of a purely large-scale model is its transparency, which allows di...

show abstract

Transformation of wave height distribution

Cited by 746 publications

References 27 publications

Airborne remote sensing applications to coastal wave research

Airborne remote sensing applications to coastal wave research

Formation of magnetite‐enriched zones in and offshore of a mesotidal estuarine lagoon: An environmental magnetic study of Tauranga Harbour and Bay of Plenty, New Zealand

Morphologic properties derived from a simple cross‐shore sediment transport model

Contact Info

Product

Resources

About