Meteotsunami Generation, Amplification and Occurrence in North-West Europe

Total Page:16

File Type:pdf, Size:1020Kb

Meteotsunami Generation, Amplification and Occurrence in North-West Europe University of Liverpool Doctoral Thesis Meteotsunami generation, amplification and occurrence in north-west Europe Thesis submitted in accordance with the requirements of the University of Liverpool for the degree of Doctor in Philosophy by David Alan Williams November 2019 ii Declaration of Authorship I declare that this thesis titled “Meteotsunami generation, amplification and occurrence in north-west Europe” and the work presented in it are my own work. The material contained in the thesis has not been presented, nor is currently being presented, either wholly or in part, for any other degree or qualification. Signed Date David A Williams iii iv Meteotsunami generation, amplification and occurrence in north-west Europe David A Williams Abstract Meteotsunamis are atmospherically generated tsunamis with characteristics similar to all other tsunamis, and periods between 2–120 minutes. They are associated with strong currents and may unexpectedly cause large floods. Of highest concern, meteotsunamis have injured and killed people in several locations around the world. To date, a few meteotsunamis have been identified in north-west Europe. This thesis aims to increase the preparedness for meteotsunami occurrences in north-west Europe, by understanding how, when and where meteotsunamis are generated. A summer-time meteotsunami in the English Channel is studied, and its generation is examined through hydrodynamic numerical simulations. Simple representations of the atmospheric system are used, and termed synthetic modelling. The identified meteotsunami was partly generated by an atmospheric system moving at the shallow- water wave speed, a mechanism called Proudman resonance. Wave heights in the English Channel are also sensitive to the tide, because tidal currents change the shallow-water wave speed. To explain meteotsunami growth in a wider range of conditions, a generalised understanding of Proudman resonance is developed through idealised simulations and analytical models. Most surprisingly, wave amplification near predictions of Proudman resonance can occur even if the instantaneous forcing speed deviates from the mean forcing speed by 18%. This amplification can happen if the atmospheric forcing remains over the meteotsunami. Broader context is given to meteotsunami case studies in north-west Europe through an 8-yr climatology. In total, 349 meteotsunamis are identified and 256 associated mesoscale atmospheric systems are classified. Of meteotsunamis between 2010–2017, 79% were smaller than 0.5 m and about half occurred in winter. Of the classified atmospheric systems, 46% were quasi-linear systems and 33% were open-cellular convection. For 45 meteotsunamis in France, the mesoscale atmospheric systems occurred within well-documented synoptic atmospheric conditions, and there is evidence of repeated favourable conditions for Proudman resonance. Finally, a new explanation of how open-cellular convection generates meteotsunamis is developed through synthetic models. Open-cellular convection is modelled as a repeating field of individual cells moving at the shallow-water wave speed. Each individual cell generates an individual wave. When these individual waves form a linear superposition, constructive interference of repeating waves can lead to a larger meteotsunami than would be expected from single individual cells. v vi Contents Declaration of Authorship iii Abstract v List of Figures xii List of Tables xv Acknowledgements xvii Chapter 1 – Introduction 1 1.1 Motivation, Problem and Solution 1 1.2 Thesis approach and structure 3 1.3 A general background of meteotsunamis 4 1.3.1 Addressing common misconceptions 4 1.3.2 Where do meteotsunamis happen? 6 1.3.3 The north-west European continental shelf 12 1.3.4 How are meteotsunamis different to other waves? 15 Chapter 2 – Relevant meteotsunami dynamics 20 2.1 The Navier-Stokes equations and shallow-water equations 20 2.2 The ocean at equilibrium 22 2.3 Forced shallow-water waves 23 2.4 Meteotsunami generation mechanisms 26 2.4.1 Proudman resonance 26 2.4.2 Greenspan resonance 29 2.4.3 Reflection and transmission 30 2.4.4 Shoaling 31 2.4.5 Refraction 32 2.4.6 Currents 33 2.4.7 Seiching 33 vii Chapter 3 – Methods overview 35 3.1 Observational methods 35 3.1.1 Identifying meteotsunamis from sea-level records 35 3.1.2 Atmospheric measurements 38 3.2 Simulating meteotsunamis 41 3.2.1 Finite-difference models 42 3.2.2 Finite-element models 42 3.2.3 Applying boundary conditions and initial conditions 43 3.2.4 Applying an atmospheric forcing 46 Chapter 4 – Paper One 48 4.0 Preamble 48 4.1 Paper Abstract 50 4.2 Introduction 50 4.3 Observations 54 4.3.1 Sea surface observations 54 4.3.2 Atmospheric observations 57 4.3.3 Analysis of observations 60 4.4 Modeling 63 4.4.1 Telemac 63 4.4.2 Atmospheric forcing 63 4.4.3 Best-estimate model 64 4.4.4 Atmospheric forcing ensembles 70 4.4.5 Wind 75 4.4.6 Tides 76 4.5 Conclusions 79 viii Chapter 5 – Paper Two 81 5.0 Preamble 81 5.1 Paper Abstract 83 5.2 Introduction 83 5.3 Methods 86 5.3.1 Hydrodynamic models 86 5.3.2 Synthetic atmospheric forcing 86 5.4 Strict Proudman resonance simulation results and discussion 89 5.5 Oceanographic factors – results and discussion 91 5.5.1 Uniform elevation change (1D-FD) 91 5.5.2 Uniform current (2D-FE) 93 5.5.3 Uniform elevation and current (2D-FE) 96 5.5.4 Bathymetric slope (2D-FE) 97 5.5.5 M2 progressive tides (2D-FE) 100 5.6 Atmospheric factors – results and discussion 103 5.6.1 Average forcing speed (1D-FD) 103 5.6.2 Variable forcing speed (1D-FD) 104 5.6.3 Time-varying amplitude of atmospheric forcing (1D-FD) 107 5.6.4 Forcing aspect ratio (2D-FD) 109 5.7 Conclusions 111 Chapter 6 – Paper Three 117 6.0 Preamble 117 6.1 Paper abstract 119 6.2 Introduction 120 6.3 Data and methods 124 6.3.1 Tide-gauge data 124 6.3.2 Isolating tsunami-like waves 127 6.3.3 NSLOTT classification 128 6.3.4 Meteotsunami classification 129 6.3.5 Classifying atmospheric weather systems 130 ix 6.4 Results and discussion 133 6.4.1 Size-exceedance rates 133 6.4.2 Seasonal and diurnal variation 139 6.4.3 Analyses of coincident mesoscale weather systems 142 6.4.4 Analyses of coincident synoptic environments 146 6.5 Conclusions 155 Chapter 7 – Paper Four 158 7.0 Preamble 158 7.1 Paper Abstract 159 7.2 Introduction 159 7.3 Modelling sea-level pressure perturbations and resultant waves 164 7.4 Results and Discussion 165 7.5 Conclusion 171 Chapter 8 – Conclusions 173 8.1 The dissertation narrative 173 8.2 Study limitations 177 8.2.1 Models 177 8.2.2 Observations 178 8.3 Rising sea levels and a changing climate 179 A Travel-time solution for waves in the English Channel 181 B Supplementary figures to Chapter 5 183 C The finite-difference model 192 D Effective Proudman resonance from an idealised NWP model 195 E The stacking correction 206 F The effect of sub-sampling data 210 Bibliography 212 x xi List of Figures 1.1 Screenshots of May 2017 Dutch meteotsunami. 2 1.2 Reported meteotsunamis around the globe. 10 1.3 The north-west European continental shelf and meteorology. 13 1.4 Surface gravity waves grouped by period. 15 2.1 The inverted barometer effect and wind set-up. 23 2.2 Understanding forced wave dynamics as a forced oscillator. 25 2.3 The fundamentals of Proudman resonant wave growth. 28 2.4 Reflection, transmission, shoaling, refraction and seiching. 31 3.1 A schematic of isolating meteotsunami signals. 36 3.2 A comparison between finite-difference and finite-element domains. 42 4.1 The English Channel study region. 52 4.2 Tide gauge measurements on 23 June 2016. 55 4.3 Radar derived precipitation rates on 23 June 2016. 56 4.4 Surface pressure and 10-m wind speed measurements on 23 June 2016. 58 4.5 Time series of observed and modelled surface pressure anomalies. 65 4.6 Plan view of simulated sea-level elevations. 67 4.7 Time series of observed and modelled sea-level elevations. 69 4.8 Idealised simulations for coastal wave generation mechanisms. 71 xii 4.9 Sea-surface elevation sensitivity to forcing angles and speeds. 72 4.10 Sea-surface elevation sensitivity to wind, amplitude and period. 74 4.11 Sensitivity of the meteotsunami to tides in the model. 77 5.1 Synthetic atmospheric pressure forcings. 88 5.2 Strict Proudman resonance simulation results. 91 5.3 Wave growth when uniformly changing elevation. 93 5.4 Analytical envelopes when including constant currents. 96 5.5 Analytical envelopes including constant currents and elevation. 97 5.6 Sea-level elevation simulations with sloping bottoms. 100 5.7 Sea-level elevation simulations with a dynamic progressive tide. 103 5.8 Sea-level elevation simulations with a variable speed forcing. 106 5.9 Analytical envelopes for a moving forcing that changes amplitude. 109 5.10 Maximum wave amplifications with two-dimensional forcings. 111 6.1 The north-west European continental shelf study region. 126 6.2 The mesoscale atmospheric system classification scheme. 132 6.3 NSLOTT annual size-exceedance rates, grouped by country. 137 6.4 Seasonal variation of meteotsunamis, grouped by country. 140 6.5 Seasonal and diurnal NSLOTT variation across all tide gauges. 141 6.6 Mesoscale atmospheric systems grouped by season and country. 144 6.7 Synoptic composite analyses. 150 6.8 The percentile distribution of Proudman-resonant regions. 152 xiii 7.1 Radar-derived precipitation of isolated cells and open cells. 161 7.2 Simulations with open cells and isolated cells.
Recommended publications
  • Nearshore Currents and Safety to Swimmers in Xai-Xai Beach Correntes Costeiras E Segurança De Banhistas Na Praia De Xai-Xai
    Antonio Mubango Hoguane et al. Journal of Integrated Coastal Zone Management / Revista de Gestão Costeira Integrada 19(4):209-220 (2019) http://www.aprh.pt/rgci/pdf/rgci-n148_Hoguane.pdf | DOI:10.5894/rgci-n148 Nearshore currents and safety to swimmers in Xai-Xai Beach Correntes costeiras e segurança de banhistas na Praia de Xai-Xai Antonio Mubango Hoguane1, @, Tor Gammelsrød2, Kai H. Christensen3, Noca Bernardo Furaca1, Bilardo António da Silva Nharreluga1, Manuel Victor Poio4 @ Corresponding author, [email protected], Tel: +258823152860 1 Centre for Marine Research and Technology, Eduardo Mondlane University, Mozambique 2 Geophysical Institute, University of Bergen, Bergen, Norway, [email protected] 3 Research and Development Department, Norwegian Meteorological Institute, Oslo, Norway, [email protected] 4 Centre for Sustainable Development for Coastal Zone, Xai-Xai, Mozambique, [email protected], Tel: +258843110000 ABSTRACT: Xai-Xai Beach is a shallow semi-enclosed lagoon, about 2,000m long, 200m wide and 3m average depth, protected from ocean swell by a reef about 0.75m above the Mean Sea Level, with small gaps along its extension. Despite being protected from ocean waves, the lagoon, which is popular with tourists, is a dangerous place to swim, with an average of 8-9 drownings each year. The present paper examines the longshore and rip currents in the lagoon as the potential cause for these fatalities. Drifters were deployed for measuring the magnitude and direction of the nearshore currents. Unidirectional, northwards, longshore currents, with velocity up to 1.4ms-1 and strong rip currents, with velocity up to 3.4ms-1, 5-10m width and duration of less than 5 minutes, were observed.
    [Show full text]
  • Destructive Meteotsunamis Along the Eastern Adriatic Coast: Overview
    Physics and Chemistry of the Earth 34 (2009) 904–917 Contents lists available at ScienceDirect Physics and Chemistry of the Earth journal homepage: www.elsevier.com/locate/pce Destructive meteotsunamis along the eastern Adriatic coast: Overview Ivica Vilibic´ *, Jadranka Šepic´ Institute of Oceanography and Fisheries, Šetalište I. Meštrovic´a 63, 21000 Split, Croatia article info abstract Article history: The paper overviews meteotsunami events documented in the Adriatic Sea in the last several decades, by Received 10 December 2008 using available eyewitness reports, documented literature, and atmospheric sounding and meteorologi- Accepted 24 August 2009 cal reanalysis data available on the web. The source of all documented Adriatic meteotsunamis was Available online 28 August 2009 examined by assessing the underlying synoptic conditions. It is found that travelling atmospheric distur- bances which generate the Adriatic meteotsunamis generally appear under atmospheric conditions doc- Keywords: umented also for the Balearic meteotsunamis (rissagas). These atmospheric disturbances are commonly Meteotsunami generated by a flow over the mountain ridges (Apennines), and keep their energy through the wave-duct Atmospheric disturbance mechanism while propagating over a long distance below the unstable layer in the mid-troposphere. Resonance Long ocean waves However, the Adriatic meteotsunamis may also be generated by a moving convective storm or gravity Adriatic Sea wave system coupled in the wave-CISK (Conditional Instability of the Second Kind) manner, not docu- mented at other world meteotsunami hot spots. The travelling atmospheric disturbance is resonantly pumping the energy through the Proudman resonance over the wide Adriatic shelf, but other resonances (Greenspan, shelf) are also presumably influencing the strength of the meteotsunami waves, especially in the middle Adriatic, full of elongated islands and with a sloping bathymetry.
    [Show full text]
  • James T. Kirby, Jr
    James T. Kirby, Jr. Edward C. Davis Professor of Civil Engineering Center for Applied Coastal Research Department of Civil and Environmental Engineering University of Delaware Newark, Delaware 19716 USA Phone: 1-(302) 831-2438 Fax: 1-(302) 831-1228 [email protected] http://www.udel.edu/kirby/ Updated September 12, 2020 Education • University of Delaware, Newark, Delaware. Ph.D., Applied Sciences (Civil Engineering), 1983 • Brown University, Providence, Rhode Island. Sc.B.(magna cum laude), Environmental Engineering, 1975. Sc.M., Engineering Mechanics, 1976. Professional Experience • Edward C. Davis Professor of Civil Engineering, Department of Civil and Environmental Engineering, University of Delaware, 2003-present. • Visiting Professor, Grupo de Dinamica´ de Flujos Ambientales, CEAMA, Universidad de Granada, 2010, 2012. • Professor of Civil and Environmental Engineering, Department of Civil and Environmental Engineering, University of Delaware, 1994-2002. Secondary appointment in College of Earth, Ocean and the Environ- ment, University of Delaware, 1994-present. • Associate Professor of Civil Engineering, Department of Civil Engineering, University of Delaware, 1989- 1994. Secondary appointment in College of Marine Studies, University of Delaware, as Associate Professor, 1989-1994. • Associate Professor, Coastal and Oceanographic Engineering Department, University of Florida, 1988. • Assistant Professor, Coastal and Oceanographic Engineering Department, University of Florida, 1984- 1988. • Assistant Professor, Marine Sciences Research Center, State University of New York at Stony Brook, 1983- 1984. • Graduate Research Assistant, Department of Civil Engineering, University of Delaware, 1979-1983. • Principle Research Engineer, Alden Research Laboratory, Worcester Polytechnic Institute, 1979. • Research Engineer, Alden Research Laboratory, Worcester Polytechnic Institute, 1977-1979. 1 Technical Societies • American Society of Civil Engineers (ASCE) – Waterway, Port, Coastal and Ocean Engineering Division.
    [Show full text]
  • A High-Amplitude Atmospheric Inertia–Gravity Wave-Induced
    A high-amplitude atmospheric inertia– gravity wave-induced meteotsunami in Lake Michigan Eric J. Anderson & Greg E. Mann Natural Hazards ISSN 0921-030X Nat Hazards DOI 10.1007/s11069-020-04195-2 1 23 Your article is protected by copyright and all rights are held exclusively by This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply. This e-offprint is for personal use only and shall not be self- archived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com”. 1 23 Author's personal copy Natural Hazards https://doi.org/10.1007/s11069-020-04195-2 ORIGINAL PAPER A high‑amplitude atmospheric inertia–gravity wave‑induced meteotsunami in Lake Michigan Eric J. Anderson1 · Greg E. Mann2 Received: 1 February 2020 / Accepted: 17 July 2020 © This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply 2020 Abstract On Friday, April 13, 2018, a high-amplitude atmospheric inertia–gravity wave packet with surface pressure perturbations exceeding 10 mbar crossed the lake at a propagation speed that neared the long-wave gravity speed of the lake, likely producing Proudman resonance.
    [Show full text]
  • Infragravity Wave Energy Partitioning in the Surf Zone in Response to Wind-Sea and Swell Forcing
    Journal of Marine Science and Engineering Article Infragravity Wave Energy Partitioning in the Surf Zone in Response to Wind-Sea and Swell Forcing Stephanie Contardo 1,*, Graham Symonds 2, Laura E. Segura 3, Ryan J. Lowe 4 and Jeff E. Hansen 2 1 CSIRO Oceans and Atmosphere, Crawley 6009, Australia 2 Faculty of Science, School of Earth Sciences, The University of Western Australia, Crawley 6009, Australia; [email protected] (G.S.); jeff[email protected] (J.E.H.) 3 Departamento de Física, Universidad Nacional, Heredia 3000, Costa Rica; [email protected] 4 Faculty of Engineering and Mathematical Sciences, Oceans Graduate School, The University of Western Australia, Crawley 6009, Australia; [email protected] * Correspondence: [email protected] Received: 18 September 2019; Accepted: 23 October 2019; Published: 28 October 2019 Abstract: An alongshore array of pressure sensors and a cross-shore array of current velocity and pressure sensors were deployed on a barred beach in southwestern Australia to estimate the relative response of edge waves and leaky waves to variable incident wind wave conditions. The strong sea 1 breeze cycle at the study site (wind speeds frequently > 10 m s− ) produced diurnal variations in the peak frequency of the incident waves, with wind sea conditions (periods 2 to 8 s) dominating during the peak of the sea breeze and swell (periods 8 to 20 s) dominating during times of low wind. We observed that edge wave modes and their frequency distribution varied with the frequency of the short-wave forcing (swell or wind-sea) and edge waves were more energetic than leaky waves for the duration of the 10-day experiment.
    [Show full text]
  • Baroclinic Instability, Lecture 19
    19. Baroclinic Instability In two-dimensional barotropic flow, there is an exact relationship between mass 2 streamfunction ψ and the conserved quantity, vorticity (η)given by η = ∇ ψ.The evolution of the conserved variable η in turn depends only on the spatial distribution of η andonthe flow, whichisd erivable fromψ and thus, by inverting the elliptic relation, from η itself. This strongly constrains the flow evolution and allows one to think about the flow by following η around and inverting its distribution to get the flow. In three-dimensional flow, the vorticity is a vector and is not in general con­ served. The appropriate conserved variable is the potential vorticity, but this is not in general invertible to find the flow, unless other constraints are provided. One such constraint is geostrophy, and a simple starting point is the set of quasi-geostrophic equations which yield the conserved and invertible quantity qp, the pseudo-potential vorticity. The same dynamical processes that yield stable and unstable Rossby waves in two-dimensional flow are responsible for waves and instability in three-dimensional baroclinic flow, though unlike the barotropic 2-D case, the three-dimensional dy­ namics depends on at least an approximate balance between the mass and flow fields. 97 Figure 19.1 a. The Eady model Perhaps the simplest example of an instability arising from the interaction of Rossby waves in a baroclinic flow is provided by the Eady Model, named after the British mathematician Eric Eady, who published his results in 1949. The equilibrium flow in Eady’s idealization is illustrated in Figure 19.1.
    [Show full text]
  • Assessment of Tsunami Hazard to the U.S. Atlantic Margin
    Marine Geology 353 (2014) 31–54 Contents lists available at ScienceDirect Marine Geology journal homepage: www.elsevier.com/locate/margeo Review article Assessment of tsunami hazard to the U.S. Atlantic margin U.S. ten Brink a,⁎,J.D.Chaytora, E.L. Geist b,D.S.Brothersa,1, B.D. Andrews a a U.S. Geological Survey, 384 Woods Hole Rd., Woods Hole, MA 02543, USA b U.S. Geological Survey, 345 Middlefield Rd., Menlo Park, CA 94025, USA article info abstract Article history: Tsunami hazard is a very low-probability, but potentially high-risk natural hazard, posing unique challenges to Received 23 May 2013 scientists and policy makers trying to mitigate its impacts. These challenges are illustrated in this assessment Received in revised form 19 February 2014 of tsunami hazard to the U.S. Atlantic margin. Seismic activity along the U.S. Atlantic margin in general is low, Accepted 22 February 2014 and confirmed paleo-tsunami deposits have not yet been found, suggesting a very low rate of hazard. However, Available online 22 March 2014 the devastating 1929 Grand Banks tsunami along the Atlantic margin of Canada shows that these events continue Communicated by: D.J.W. Piper to occur. Densely populated areas, extensive industrial and port facilities, and the presence of ten nuclear power plants along the coast, make this region highly vulnerable to flooding by tsunamis and therefore even low- Keywords: probability events need to be evaluated. submarine landslides We can presently draw several tentative conclusions regarding tsunami hazard to the U.S. Atlantic coast. Land- meteo-tsunami slide tsunamis likely constitute the biggest tsunami hazard to the coast.
    [Show full text]
  • Meteotsunami Occurrence in the Gulf of Finland Over the Past Century Havu Pellikka1, Terhi K
    https://doi.org/10.5194/nhess-2020-3 Preprint. Discussion started: 8 January 2020 c Author(s) 2020. CC BY 4.0 License. Meteotsunami occurrence in the Gulf of Finland over the past century Havu Pellikka1, Terhi K. Laurila1, Hanna Boman1, Anu Karjalainen1, Jan-Victor Björkqvist1, and Kimmo K. Kahma1 1Finnish Meteorological Institute, P.O. Box 503, FI-00101 Helsinki, Finland Correspondence: Havu Pellikka (havu.pellikka@fmi.fi) Abstract. We analyse changes in meteotsunami occurrence over the past century (1922–2014) in the Gulf of Finland, Baltic Sea. A major challenge for studying these short-lived and local events is the limited temporal and spatial resolution of digital sea level and meteorological data. To overcome this challenge, we examine archived paper recordings from two tide gauges, Hanko for 1922–1989 and Hamina for 1928–1989, from the summer months of May–October. We visually inspect the recordings to 5 detect rapid sea level variations, which are then digitized and compared to air pressure observations from nearby stations. The data set is complemented with events detected from digital sea level data 1990–2014 by an automated algorithm. In total, we identify 121 potential meteotsunami events. Over 70 % of the events could be confirmed to have a small jump in air pressure occurring shortly before or simultaneously with the sea level oscillations. The occurrence of meteotsunamis is strongly connected with lightning over the region: the number of cloud-to-ground flashes over the Gulf of Finland were on 10 average over ten times higher during the days when a meteotsunami was recorded compared to days with no meteotsunamis in May–October.
    [Show full text]
  • Numerical Modeling of Meteotsunami–Tide Interaction in the Eastern Yellow Sea
    atmosphere Article Numerical Modeling of Meteotsunami–Tide Interaction in the Eastern Yellow Sea Ki-Young Heo 1, Jae-Seon Yoon 2, Jae-Seok Bae 3 and Taemin Ha 4,* 1 Marine Disaster Research Center, Korea Institute of Ocean Science & Technology, Busan 49111, Korea 2 Rural Research Institute, Korea Rural Community Corporation, Ansan 15634, Korea 3 Emergency Management Office, Korea Hydro & Nuclear Power Co., Ltd., Gyeongju 38120, Korea 4 Department of Civil Engineering, Kangwon National University, Samcheok 25913, Korea * Correspondence: [email protected]; Tel.: +82-033-570-6514 Received: 24 May 2019; Accepted: 1 July 2019; Published: 2 July 2019 Abstract: Meteotsunamis originating from atmospheric pressure disturbances have frequently occurred in oceans worldwide and their destructive long waves have recently threatened local coastal communities. In particular, meteotsunamis occurring in the Yellow Sea caused unexpected casualties and property damage to local communities on the western coast of the Korean Peninsula in 2007 and 2008. These events attracted the attention of many engineers and scientists because abrupt extreme waves have struck several coasts and ports even under fine weather conditions. Furthermore, the Yellow Sea has the highest tide and most powerful tidal currents in the world, and consequently, meteotsunami events there could be more destructive and harmful to local coastal communities when such events occur during high tide or a critical phase with strong tidal currents. In this study, numerical experiments were conducted to identify the qualitative effect of the interaction between a meteotsunami and the tide on the generation and amplification mechanisms of meteotsunamis occurring in the Yellow Sea. In general, small-scale meteotsunamis, such as those that occur in the Yellow Sea, should be analyzed using a high-resolution modeling system because water motions can be affected by local terrain.
    [Show full text]
  • HEC-25 3Rd Ed
    Publication No. FHWA-HIF-19-059 January 2020 Hydraulic Engineering Circular No. 25 Highways in the Coastal Environment Third Edition Page Intentionally Left Blank Technical Report Documentation Page 1. Report No. 2. Government Accession No. 3. Recipient’s Catalog No. FHWA HIF-19-059 4. Title and Subtitle 5. Report Date HIGHWAYS IN THE COASTAL ENVIRONMENT January 2020 Hydraulic Engineering Circular Number 25 6. Performing Organization Code Third Edition 7. Author(s) 8. Performing Organization Report No. Scott L. Douglass and Bret M. Webb 9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) South Coast Engineers PO Box 72 Fairhope, AL 36533 11. Contract or Grant No. DTFH61-16-D-00033 12. Sponsoring Agency Name and Address 13. Type of Report and Period Covered Office of Bridges and Structures Technical Report Federal Highway Administration November 2017-December 2019 1200 New Jersey Avenue, S.E. 14. Sponsoring Agency Code Washington, D.C. 20590 15. Supplementary Notes Project Manager: Brian Beucler, FHWA Office of Bridges and Structures Technical Reviewers: Joe Krolak, Tina Hodges, Rob Kafalenos, Kornel Kerenyi, Rob Hyman, Paul Sharp, Eric Brown, Jia-Dzan (Jerry) Shen, Stephanie Smallegan, Thomas (Beau) Buhring Technical Editor: Valarie Arms 16. Abstract This manual presents tools for the planning, design, and operation of highways in the coastal environment. It focuses on roads near the coast that are influenced by coastal tides and waves constantly, or occasionally during storms. FHWA estimates that there are more than 60,000 miles of these “coastal highways” in the US. A primary goal is the integration of coastal engineering principles and practices in the planning and design of these roads and bridges to make them more resilient.
    [Show full text]
  • The Life Cycle of Baroclinic Eddies in a Storm Track Environment
    3498 JOURNAL OF THE ATMOSPHERIC SCIENCES VOLUME 57 The Life Cycle of Baroclinic Eddies in a Storm Track Environment ISIDORO ORLANSKI AND BRIAN GROSS Geophysical Fluid Dynamics Laboratory, Princeton, New Jersey (Manuscript received 15 April 1999, in ®nal form 1 March 2000) ABSTRACT The life cycle of baroclinic eddies in a controlled storm track environment has been examined by means of long model integrations on a hemisphere. A time-lagged regression that captures disturbances with large me- ridional velocities has been applied to the meteorological variables. This regressed solution is used to describe the life cycle of the baroclinic eddies. The eddies grow as expected by strong poleward heat ¯uxes at low levels in regions of strong surface baroclinicity at the entrance of the storm track, in a manner similar to that of Charney modes. As the eddies evolve into a nonlinear regime, they grow deeper by ¯uxing energy upward, and the characteristic westward tilt exhibited in the vorticity vanishes by rotating into a meridional tilt, in which the lower-level cyclonic vorticity center moves poleward and the upper-level center moves equatorward. This rather classical picture of baroclinic evolution is radically modi®ed by the simultaneous development of an upper-level eddy downstream of the principal eddy. The results suggest that this eddy is an integral part of a self-sustained system here named as a couplet, such that the upstream principal eddy in its evolution ¯uxes energy to the upper-level downstream eddy, whereas at lower levels the principal eddy receives energy ¯uxes from its downstream companion but grows primarily from baroclinic sources.
    [Show full text]
  • Meteorological Tsunami of 19 March 2017 in the Persian Gulf: Observations and Analyses
    Pure Appl. Geophys. Ó 2019 The Author(s) https://doi.org/10.1007/s00024-019-02263-8 Pure and Applied Geophysics Meteorological Tsunami of 19 March 2017 in the Persian Gulf: Observations and Analyses 1 2 3,4 5 MOHAMMAD HEIDARZADEH, JADRANKA Sˇ EPIC´ , ALEXANDER RABINOVICH, MOHAMMADREZA ALLAHYAR, 6 7 ALI SOLTANPOUR, and FAROKH TAVAKOLI Abstract—On 19 March 2017, destructive tsunami-like waves is highly vulnerable to extreme, weather-induced tsunami-like impacted the northeast shore of the Persian Gulf (PG). The maxi- waves. mum surveyed runup of about 3 m was observed at Dayyer in southern Iran, where damaging waves inundated the land for a Key words: Persian Gulf, meteotsunami, extreme waves, at- distance of * 1 km and resulted in the deaths of five people. mospheric waves, tide gauge data, wavelet analysis, remote Because the PG has always been considered safe from extreme sensing. oceanic waves, the event was totally unexpected. In this study, we examined sea level data from 12 stations across the PG and a variety of meteorological information, including satellite imagery, high-altitude isohypse maps and high-resolution air pressure records from 47 instruments along the PG. Our results show that 1. Introduction the event was very local, with recorded maximum trough-to-crest wave heights of 197 cm at Dayyer and 234 cm at Asaluyeh, near- field cities in Iran located * 80 km apart. The dominant wave The Persian Gulf (PG) is an extensive inland sea, periods were in the range of 15–20 min. At all distant tide gauges, located between the Arabian Peninsula and Iran, that the observed wave heights were \ 35 cm.
    [Show full text]