NSFGEO-NERC: Toward a New Picture of the Multifaceted Meteotsunami

Lead Research Organisation: Keele University
Department Name: Faculty of Natural Sciences


As awareness of the meteotsunami (MT) (tsunami-like wave of meteorological origin) threat to human life and coastal infrastructure is growing (e.g., >100/year MT events just on the Great Lakes), so is the need for understanding and forecasting it. However, knowledge acquired in the study of seismic tsunami is not readily transferable to MT research, because MT evolution is in important aspects qualitatively different: it is much more nonlinear and more strongly affected by bottom friction. Moreover, a realistic reconstruction of MT evolution is almost impossible because of the current poor spatial and temporal resolution MT observations, overwhelmingly confined to the shoreline. Therefore, the picture of the nonlinear transformation of a MT from generation to its shoreline manifestation is substantially incomplete. Since the MTs tend to disintegrate into very short (down to ~10s) pulses, even modern tidal gauges (1 min resolution) fail to capture essential features of its evolution. This fundamental knowledge gap is evident in our recently-published high-resolution MT observations off the Louisiana coast, which show a highly-complex, multi-scale non-linear disintegration of the MT wave. Together with other gaps identified in the literature, the observations strongly suggest revising of the current MT paradigm.

Field experiment:

A 3-year field experiment will be conducted to collect unprecedented high-resolution (up to 4 Hz) MT observations off the Louisiana coast, to capture fully the details of MT evolution. The site is a unique "natural laboratory": (i) it experiences 20-30 frontal passages per cold season (high MT probability); (ii) allows for the study of bottom-induced dissipation over a range of sedimentary types (coarse sands to mud); (iii) crucially, it is already monitored by WAVCIS (http://www.wavcis.lsu.edu/, Coastal Studies Institute, LSU), an ocean-observing system network sponsored by NOAA and BOEM. WAVCIS will be enhanced with high-resolution capabilities and five new stations located both on the coast and offshore. The observations will be organized into a public database.

Modelling: The proposed work is based on the hypothesis that in a generic Proudman-resonated MT event trapped waves are also excited. Although usually less dangerous, they might represent an important part of the process, and behave as precursors to the main wave. The work focuses on the propagation stage of MT: a theoretical description of the nonlinear evolution of both free and trapped components of MT will be developed, including solitary waves, and will be validated for the real topography, and accounting for realistic bottom friction.

MT warning: Data analysis and model development will be integrated into an evaluate-learn-correct cycle that will improve our representation of the process and our ability to anticipate MT events. Effective numerical models and early-warning strategies will be developed and tested. Presently, MT early-warning systems mostly rely on interpreting atmospheric data. The new high-resolution observations will be used to incorporate in this cycle elements of real-time ocean response.

Planned Impact

The public database of high-resolution observations will provide indispensable information for advancing and validating our understanding of MT phenomenon. It will also produce unique statistics and allow for testing of all future theoretical and numerical developments. Understanding the MT evolution and improving MT early-warning strategies to mitigate the MT hazard. The project will support the education of two Ph.D. students. The project will rely on the UF K-12 outreach programme to actively involve high-school teachers and underserved student communities in the research, and to disseminate results.

Coastal communities:

More efficient and accurate alerts will translate into better MT hazard mitigation. Reliable forecast of MT processes such as solibore cascades and the formation of dangerous Mach-stem solitons, as well as forecasts of coastal-damage hot spots will warn and protect small fishing vessels and coastal communities.

K-12 education:

The PIs of the project will collaborate with UF's Centre for Pre-collegiate Education and Training (CPET) to educate and disseminate the methods and findings of the project, by actively involve high-school students from Florida underserved communities in the research. This goal will be achieved in two ways. (i) In each year of the project, a high-school teacher selected by CPET will intern with the project team for three weeks during summer, participating in the development of the MT database. The teacher will study the MT phenomenon and the methods and criteria used to identify MT events; will develop a curriculum, and implement it in their high school; select and guide his/her students in the collection of NOAA NEXRAD and HRRR data, and identification of MT events; present the results with the students every year at a scientific symposium organized by CPET. (ii) Independent of this project, UF CPET offers the Student Science Training Programme (SSTP), a 7-week residential research programme for high school students who have completed their junior year and are considering medicine, maths, computer, science, or engineering careers. The programme's emphasis is research participation with a UF faculty research scientist and his or her research team. The project will select one or more students who will: engage in research associated with the project for 30 hours each week; attend a lecture series on current research topics; and participate in a UF honours seminar class. Students enrolled in a Florida high school have the option to earn dual enrolment credit.

Graduate education:

The project will support two Ph.D. graduate students and provide the material for two Ph.D. theses.
Description Edge waves are the infragravity surface waves trapped by nearshore topography, They are important in dynamics of sediments and flooding on mildly sloping beaches, and might be linked with meteotsunamis. The only established mechanism of their generation is by swell via nonlinear interactions. We showed that edge waves might be also
generated directly by wind and put forward a mathematical model describing the novel mechanism of their excitation. The main conclusion of this direction of our work is paradigm changing: wind should be always taken into acount for modelling edge waves.
Exploitation Route The insight and the proposed mathematical model of edge wave generation can be implemented in engineering models of nearshore dynamics.
Sectors Environment

Title Reanalisys of "SandyDuck'97" dataset 
Description The most comprehensive edge wave dataset produced as a result of the "SandyDuck'97" field experiment has been subjected to reanalysys from the viewpoint of eqge wave generation by wind. Now, the reorganised data set enables one to identify the situations where edge waves are likely to be generated by wind. 
Type Of Material Improvements to research infrastructure 
Year Produced 2022 
Provided To Others? Yes  
Impact The paradigm breaking idea that edge wave can be also generated directly by wind has to be implemented into the nearshore modelling routines. The re-organised data base is the only one which could be used for testing and tuning of the new models accounting for wind generation of edge waves. 
Description EPSRC funded Network "Maths Foresees" 
Organisation University of Leeds
Department Maths Foresees
Country United Kingdom 
Sector Academic/University 
PI Contribution "Maths Foresees", a Network funded by EPSRC (PI : Prof. Onno Bohove, Leeds University) is aimed at bringing together mathematicians and people from various UK industries to address UK challnges in the areas broadly described as environmental fluid dynamics (floods, climate dynamics, ship safety). I participated in the activities of the network (the last meetings in September 2017 and January 2018) to share the results obtained as a result of the Nerc grants ( NE/R012202/1, NE/M016269/1) and look for new collaborations and partnerships. The Network served as a forum for echanging ideas, results (including preliminary ones) and informal discussions with academics and industry.
Collaborator Contribution The Network funded my participation in the meetings. I had very valuable interactions which are are impossible to characterise in monetary terms. It also provided funding for a feaibility study carried out in Hull.
Impact http://www1.maths.leeds.ac.uk/mathsforesees/
Start Year 2015
Description TAU 
Organisation Tel Aviv University
Country Israel 
Sector Academic/University 
PI Contribution We had intense discussions on how to interpret observations of short wind waves under sharply increased wind carried out in the Prof. Shemer wind wave tank. Our simulations could be used for qualitative understanding only, since we did not model the capillary effects important for the TA tank.
Collaborator Contribution Several visits of the PI were supported via Sackler Scholar Fellowship and TAU. Prof. Shemer carried experiments with instantly increasing wind which were helpful for our understanding and progress of the project. There is also a collaboration with Dr Toledo and his group on the issues concerned with the fundamentals of nonlinear wave interactions and infra-gravity waves. Dr Toledo visited Keele several times. VS visited TAU in January 2020.
Impact No immediate tangible outcomes have resulted from the collaboration with the Shemer group. Both sides have better understood limitations of the models and what is possible to observe in a relatively small facility. Collaboration with Dr Toledo resulted in a joint paper (Ocean Modelling 2017 http://dx.doi.org/10.1016/j.ocemod.2017.03.003) and advance in our understanding of dynamics of infra-gravity waves in coastal waters.
Start Year 2016