ORCID Profile
0000-0002-5570-3446
Current Organisations
University of California, San Francisco
,
University of Otago
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Theoretical and Applied Mechanics | Glaciology | Physical Geography and Environmental Geoscience | Earth Sciences not elsewhere classified
ANZSRC Socio-Economic Objective (SEO)
Expanding Knowledge in the Earth Sciences | Climate Change Models |
Related Links
Publications
Evolution of Directional Wave Spectra Through Finite Regular and Randomly Perturbed Arrays of Scatterers
Publisher: Society for Industrial & Applied Mathematics (SIAM)
Date: 2015
DOI: 10.1137/140973906
Wave–ice interactions in the marginal ice zone. Part 2: Numerical implementation and sensitivity studies along 1D transects of the ocean surface
Publisher: Elsevier BV
Date: 11-2013
Reflection and transmission of ocean wave spectra by a band of randomly distributed ice floes
Publisher: International Glaciological Society
Date: 2015
Abstract: A new ocean wave/sea-ice interaction model is proposed that simulates how a directional wave spectrum evolves as it travels through an arbitrary finite array of circular ice floes, where wave/ ice dynamics are entirely governed by wave-scattering effects. The model is applied to characterize the wave reflection and transmission properties of a strip of ice floes, such as an ice edge band. A method is devised to extract the reflected and transmitted directional wave spectra produced by the array. The method builds upon an integral mapping from polar to Cartesian coordinates of the scattered wave components. Sensitivity tests are conducted for a row of floes randomly perturbed from a regular arrangement. Results for random arrays are generated using ensemble averaging. A realistic ice edge band is then reconstructed from field experiment data. Simulations show good qualitative agreement with the data in terms of transmitted wave energy and directional spreading. In particular, it is observed that short waves become isotropic quickly after penetrating the ice field.
Ocean surface wave evolvement in the Arctic Basin
Publisher: American Geophysical Union (AGU)
Date: 11-2009
DOI: 10.1029/2009GL040676
An idealized wave–ice interaction model without subgrid spatial or temporal discretizations
Publisher: International Glaciological Society
Date: 2015
Abstract: A new numerical implementation is proposed for a wave-ice interaction model. It is applied to an idealized transect geometry. Wave attenuation due to ice floes and wave-induced ice fracture are both included in the model. The new method alleviates the need for subgrid spatial or temporal discretizations, thereby facilitating future integration of wave-ice interactions into large-scale coupled models.
A three‐dimensional model of wave attenuation in the marginal ice zone
Publisher: American Geophysical Union (AGU)
Date: 12-2010
DOI: 10.1029/2009JC005982
Abstract: A three‐dimensional model of wave scattering by a large array of floating thin elastic plates is used to predict the rate of ocean wave attenuation in the marginal ice zone in terms of the properties of the ice cover and the incoming wavefield. This is regarded as a small step toward assimilating interactions of ocean waves with areas of sea ice into oceanic general circulation models. Numerical results confirm previous findings that attenuation is predominantly affected by wave period and by the average thickness of the ice cover. It is found that the shape and distribution of the floes and the inclusion of an Archimedean draft has little impact on the attenuation produced. The model demonstrates a linear relationship between ice cover concentration and attenuation. An additional study is conducted into the directional evolvement of the wavefield, where collimation and spreading can both occur, depending on the physical circumstances. Finally, the attenuation predicted by the new three‐dimensional model is compared with an existing two‐dimensional model and with two sets of experimental data, with the latter producing convincing agreement.
An Autonomous Approach to Observing the Seasonal Ice Zone in the Western Arctic
Publisher: The Oceanography Society
Date: 06-2017
The decay of flexural-gravity waves in long sea ice transects
Publisher: The Royal Society
Date: 24-06-2009
Abstract: Flexural oscillations of floating sea ice sheets induced by ocean waves travelling at the boundary between the ice and the water below can propagate great distances. But, by virtue of scattering, changes of ice thickness and other properties encountered during the journey affect their passage, notwithstanding attenuation arising from several other naturally occurring agencies. We describe here a two-dimensional model that can simulate wave scattering by long (approx. 50 km) stretches of inelastic sea ice, the goal being to replicate heterogeneity accurately while also assimilating supplementary processes that lead to energy loss in sea ice at scales that are amenable to experimental validation. In work concerned with scattering from solitary or juxtaposed stylized features in the sea ice canopy, reflection and transmission coefficients are commonly used to quantify scattering, but on this occasion, we use the attenuation coefficient as we consider that it provides a more helpful description when dealing with long sequences of adjoining scatterers. Results show that scattering and viscosity both induce exponential decay and we observe three distinct regimes: (i) low period, where scattering dominates, (ii) high period, where viscosity dominates, and (iii) a transition regime. Each regime’s period range depends on the sea ice properties including viscosity, which must be included for the correct identification of decay rate.
Wave–ice interactions in the marginal ice zone. Part 1: Theoretical foundations
Publisher: Elsevier BV
Date: 11-2013
Oxygen Perfusion (Persufflation) of Human Pancreata Enhances Insulin Secretion and Attenuates Islet Proinflammatory Signaling
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 2019
On the calculation of an attenuation coefficient for transects of ice-covered ocean
Publisher: The Royal Society
Date: 24-08-2011
Abstract: Exponential attenuation of ocean surface waves in ice-covered regions of the polar seas is modelled in a two-dimensional, linear setting, assuming that the sea ice behaves as a thin-elastic plate. Attenuation is produced by natural features in the ice cover, with three types considered: floes, cracks and pressure ridges. An inelastic d ing parameterization is also incorporated. Efficient methods for obtaining an attenuation coefficient for each class of feature, involving an investigation of wave interaction theory and averaging methods, are sought. It is found that (i) the attenuation produced by long floes can be obtained from the scattering properties of a single ice edge and (ii) wave interaction theory in ice-covered regions requires evanescent and d ed-propagating motions to be included when scattering sources are relatively nearby. Implications for the integration of this model into an oceanic general circulation model are also discussed.
Model sensitivity analysis of scattering-induced attenuation of ice-coupled waves
Publisher: Elsevier BV
Date: 2012
The transient response of floating elastic plates to wavemaker forcing in two dimensions
Publisher: Elsevier BV
Date: 2012
Attenuation and directional spreading of ocean wave spectra in the marginal ice zone
Publisher: Cambridge University Press (CUP)
Date: 09-02-2016
DOI: 10.1017/JFM.2016.21
Abstract: A theoretical model is used to study wave energy attenuation and directional spreading of ocean wave spectra in the marginal ice zone (MIZ). The MIZ is constructed as an array of tens of thousands of compliant circular ice floes, with randomly selected positions and radii determined by an empirical floe size distribution. Linear potential flow and thin elastic plate theories model the coupled water–ice system. A new method is proposed to solve the time-harmonic multiple scattering problem under a multidirectional incident wave forcing with random phases. It provides a natural framework for tracking the evolution of the directional properties of a wave field through the MIZ. The attenuation and directional spreading are extracted from ensembles of the wave field with respect to realizations of the MIZ and incident forcing randomly generated from prescribed distributions. The averaging procedure is shown to converge rapidly so that only a small number of simulations need to be performed. Far-field approximations are investigated, allowing efficiency improvements with negligible loss of accuracy. A case study is conducted for a particular MIZ configuration. The observed exponential attenuation of wave energy through the MIZ is reproduced by the model, while the directional spread is found to grow linearly with distance. The directional spreading is shown to weaken when the wavelength becomes larger than the maximum floe size.
Antarctic ice shelf disintegration triggered by sea ice loss and ocean swell
Publisher: Springer Science and Business Media LLC
Date: 06-2018
DOI: 10.1038/S41586-018-0212-1
Abstract: Understanding the causes of recent catastrophic ice shelf disintegrations is a crucial step towards improving coupled models of the Antarctic Ice Sheet and predicting its future state and contribution to sea-level rise. An overlooked climate-related causal factor is regional sea ice loss. Here we show that for the disintegration events observed (the collapse of the Larsen A and B and Wilkins ice shelves), the increased seasonal absence of a protective sea ice buffer enabled increased flexure of vulnerable outer ice shelf margins by ocean swells that probably weakened them to the point of calving. This outer-margin calving triggered wider-scale disintegration of ice shelves compromised by multiple factors in preceding years, with key prerequisites being extensive flooding and outer-margin fracturing. Wave-induced flexure is particularly effective in outermost ice shelf regions thinned by bottom crevassing. Our analysis of satellite and ocean-wave data and modelling of combined ice shelf, sea ice and wave properties highlights the need for ice sheet models to account for sea ice and ocean waves.
Wave scattering by multiple rows of circular ice floes
Publisher: Cambridge University Press (CUP)
Date: 09-10-2009
DOI: 10.1017/S0022112009991017
Abstract: A three-dimensional model of ocean-wave scattering in the marginal ice zone is constructed using linear theory under time-harmonic conditions. In idual floes are represented by circular elastic plates and are permitted to have a physically realistic draught. These floes are arranged into a finite number of parallel rows, and each row possesses an infinite number of identical floes that are evenly spaced. The floe properties may differ between rows, and the spacing between the rows is arbitrary. The vertical dependence of the solution is expanded in a finite number of modes, and through the use of a variational principle, a finite set of two-dimensional equations is generated from which the full-linear solution may be retrieved to any desired accuracy. By dictating the periodicity in each row to be identical, the scattering properties of the in idual rows are combined using transfer matrices that take account of interactions between both propagating and evanescent waves. Numerical results are presented that investigate the differences between using the three-dimensional model and using a two-dimensional model in which the rows are replaced with strips of ice. Furthermore, Bragg resonance is identified when the rows are identical and equi-spaced, and its reduction when the inhomogeneities, that are accommodated by the model, are introduced is shown.
Linear wave forcing of an array of axisymmetric ice floes
Publisher: Oxford University Press (OUP)
Date: 04-12-2009
Hydroelastic response of floating elastic discs to regular waves. Part 2. Modal analysis
Publisher: Cambridge University Press (CUP)
Date: 16-04-2013
DOI: 10.1017/JFM.2013.124
Abstract: Validation of a linear numerical model of wave interactions with floating compliant discs is sought using data obtained from the wave basin experiments reported in Part 1 (Montiel et al. J. Fluid Mech. , vol. 723, 2013, pp. 604–628). Comparisons are made for both single-disc tests and the two-disc tests in which wave interactions between discs are observed. The deflection of the disc or discs is separated into the natural modes of vibration in vacuo . The decomposition allows the rigid-body motions and flexural motions to be analysed separately. Rigid-body motions are accurately replicated by the numerical model but, although passable agreement is found, the litudes of flexural modes are consistently overestimated. Extensions of the numerical model are used to discount the experimental configuration as a source of the discrepancies. An enhanced viscoelastic model for the discs is also proposed, which results in improved model/data agreement for the flexural motions but cannot account for all of the disagreement.
Hydroelastic response of floating elastic discs to regular waves. Part 1. Wave basin experiments
Publisher: Cambridge University Press (CUP)
Date: 16-04-2013
DOI: 10.1017/JFM.2013.123
Abstract: A series of wave basin experiments is reported that investigates the flexural response of one or two floating thin elastic discs to monochromatic waves. The work is motivated by numerical model validation. Innovative techniques are used to ensure the experimental configuration is consistent with the model. This demands linear motions, time-harmonic conditions, homogeneity of the plate and the restriction of horizontal motions of the disc or discs. An optical remote sensing device is employed to record the deflection of the discs accurately. Tests involving a single disc and two discs are conducted for a range of disc thicknesses, incident wave steepnesses, frequencies and, in the case of two discs, geometrical arrangements. A data processing technique is used to decompose the raw data into its spectral harmonics and filter the higher-order components. Pointwise comparisons of the linear first-order component of the experimental deflection with numerical predictions are presented. Satisfying agreement is found, although the model consistently over predicts the deflection. Disc–disc interactions are observed in the two-disc tests. A brief discussion of the shortcomings of the pointwise analysis, with associated possible sources of discrepancy, provides a link to the study reported in Part 2 (Montiel et al. J. Fluid Mech. , vol. 723, 2013, pp. 629–652).
Related Organisations
University Of California, San Francisco
Location: United States of America
Massachusetts General Hospital-Harvard University
Location: United States of America
Related Funding Activities
Discovery Projects - Grant ID: DP200102828
Start Date: 06-2020
End Date: 06-2024
Amount: $349,000.00
Funder: Australian Research Council
View Funded Activity