Development of a Forecast Process for Meteotsunami Events in the Gulf of Mexico Leilani D

Total Page:16

File Type:pdf, Size:1020Kb

Development of a Forecast Process for Meteotsunami Events in the Gulf of Mexico Leilani D University of South Florida Scholar Commons Graduate Theses and Dissertations Graduate School 11-4-2016 Development of a Forecast Process for Meteotsunami Events in the Gulf of Mexico Leilani D. Paxton University of South Florida, [email protected] Follow this and additional works at: http://scholarcommons.usf.edu/etd Part of the Environmental Sciences Commons, and the Meteorology Commons Scholar Commons Citation Paxton, Leilani D., "Development of a Forecast Process for Meteotsunami Events in the Gulf of Mexico" (2016). Graduate Theses and Dissertations. http://scholarcommons.usf.edu/etd/6564 This Thesis is brought to you for free and open access by the Graduate School at Scholar Commons. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Scholar Commons. For more information, please contact [email protected]. Development of a Forecast Process for Meteotsunami Events in the Gulf of Mexico by Leilani D. Paxton A thesis submitted in partial fulfillment of the requirements for the degree of Master of Environmental Science and Policy School of Geosciences College of Arts and Sciences University of South Florida Major Professor: Jennifer Collins, Ph.D. Kamal Alsharif, Ph.D. Mark Luther, Ph.D. Date of Approval: November 4, 2016 Keywords: Seiche, Frontal Systems, Barometric Pressure Anomaly Copyright © 2016, Leilani D. Paxton DEDICATION I dedicate this to my loving family and my dog Bořivoj. ACKNOWLEDGMENTS First, I would like to thank my committee: Dr. Jennifer Collins, Dr. Kamal Alsharif, and Dr. Mark Luther. I would also like to thank others that provided support and suggestions including Dr. Steve Meyers, Dr. Thomas Wahl, Dr. Ivica Vilibić and Heather Key. Finally many thanks to my supportive parents for their insight and guidance through this process. TABLE OF CONTENTS LIST OF TABLES ......................................................................................................................... iii LIST OF FIGURES ....................................................................................................................... iv ABSTRACT .................................................................................................................................. vii CHAPTER 1: INTRODUCTION ................................................................................................... 1 1.1 Meteotsunami Description and Identification .......................................................... 1 1.2 Distribution and Abundance .................................................................................... 2 1.3 Formation and Propagation ..................................................................................... 5 1.4 The West Florida Continental Shelf ........................................................................ 8 CHAPTER 2: RESEARCH DESIGN ........................................................................................... 10 2.1 Problem Statement ................................................................................................. 10 2.2 Research Objectives ............................................................................................... 10 2.3 Research Questions ................................................................................................ 11 2.4 Study Area ............................................................................................................. 12 2.5 Methodology .......................................................................................................... 15 CHAPTER 3: RESULTS AND DISCUSSION ............................................................................ 21 3.1 Introduction ............................................................................................................ 21 3.2 Statistical Analysis ................................................................................................. 22 3.2.1 Temporal Analysis ........................................................................................... 24 3.2.2 Physical Analysis ............................................................................................. 26 3.2.3 Geographical Analysis ..................................................................................... 28 3.2.4 Regression Analysis ......................................................................................... 29 3.3 Case Studies ........................................................................................................... 29 3.3.1 Naples, 12 March 2010 .................................................................................... 30 3.3.2 Naples 9 June 2012 .......................................................................................... 33 3.3.3 Naples 27 March 2015 ..................................................................................... 36 3.3.4 Naples 11 January 2012 ................................................................................... 39 3.3.5 Naples 15 April 2009 ....................................................................................... 42 3.3.6 Clearwater 15 April 2013................................................................................. 45 3.3.7 Clearwater 17 November 2014 ........................................................................ 48 3.3.8 Clearwater 27 February 2010........................................................................... 51 3.3.9 Clearwater 15 February 2013........................................................................... 54 3.3.10 Clearwater 12 February 2010......................................................................... 57 3.3.11 Cedar Key 15 July 2010 ................................................................................. 60 CHAPTER 4: DEVELOPING A FORECAST PROCESS .......................................................... 63 i 4.1 Introduction ............................................................................................................ 63 4.2 Long Term Detection ............................................................................................. 63 4.3 Short Term Detection ............................................................................................. 65 CHAPTER 5: SUMMARY AND CONCLUSIONS .................................................................... 68 5.1 Summary ................................................................................................................ 68 5.3 Conclusions ............................................................................................................ 70 REFERENCES ............................................................................................................................. 72 APPENDIX A: DATA LISTING ................................................................................................. 75 ii LIST OF TABLES Table 1. Optimal speeds for meteotsunami formation. ............................................................... 9 Table 2. A comparison of the 1990 and 2014 populations in the study area (US Census Bureau 2014, US Census Bureau 1990). .................................................................... 11 Table 3. Tide gauge location, ID, latitude, longitude, mean range and diurnal range. ............. 15 Table 4. Missing water level data. ............................................................................................ 16 Table 5. Selected cases (See Appendix for all cases). .............................................................. 23 Table 6. Meteotsunami height change (m) decision matrix for pressure and wind forcing in development areas. ..................................................................................... 66 iii LIST OF FIGURES Figure 1. A representation of the generation of the catastrophic meteotsunami in Nagasaki Bay, 31 March 1979 (Monserrat, Vilibic, and Rabinovic 2006) from: Nat. Hazards Earth Syst. Sci., 6, 1035-1051, 2006 http://www.nat- hazards-earth-syst-sci.net/6/1035/2006/ doi:10.5194/nhess-6-1035-2006 © Author(s) 2006. This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 2.5 License. ................................................. 3 Figure 2. West Florida Continental Shelf Bathymetry with nearshore depths indicted in 20 m increments (black) and optimal speed of the pressure disturbance for that depth (white) to produce a meteotsunami. .................................................................... 8 Figure 3. Florida Gulf of Mexico coastal counties in the area of study. .................................... 13 Figure 4. NOAA Tide Gauge Locations in the Florida Gulf of Mexico coastal area of study. ........................................................................................................................... 14 Figure 5. Examples of raw tide data, de-tided data, and filtered data from Clearwater Beach which include cases A and B. .......................................................................... 18 Figure 6. Predicted astronomical tides and measured water levels at Clearwater Beach. The blue line shows the predicted astronomical tide as calculated by NOAA, the green line shows the observed water levels, and the red line shown in the legend refers to any preliminary data not yet verified (no preliminary data exists in this graph). .................................................................................................... 19 Figure 7. Example of a possible meteotsunami
Recommended publications
  • 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.
    [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]
  • Hurricane Waves in the Ocean
    WAVE-INDUCED SURGES DURING HURRICANE OPAL Chung-Sheng Wu*, Arthur A. Taylor, Jye Chen and Wilson A. Shaffer Meteorological Development Laboratory National Weather Service/NOAA, Silver Spring, Maryland 1. INTRODUCTION Hurricanes storm surges and waves at the coastline Holliday (1977) developed a simple formula relating the have been the cause of damages in the coastal zone. cyclone’s pressure drop to maximum sustained wind for On the U.S. Gulf Coast, for example, Hurricane Opal the Western Pacific. A more general form was (1995) made landfall near the time of low tide and proposed by Holland (1980). The merit of these models resulted in severe flooding by storm surges and waves. is that they are analytical models for the surface wind Storm surge can penetrate miles inland from the coast. profile in a hurricane. A similar formulation was applied Waves ride above the surge levels, causing wave runup to the wave model in the present work. The framework and mean water level set-up. These wave effects are of the hurricane wave model is described below. significant near the landfall area and are affected by the process that hurricane approaches the coastline. 2.1 HURRICANE WIND AND STORM SURGES During 1950-1977, hurricane wave models based on Holland (1980) employed a standard pressure profile for significant wave height and period were developed (e.g. a tropical cyclone and obtained the popular gradient Bretschneider, 1957; Ross, 1976) for marine weather wind profile. Jelesnianski and Taylor (1976) assumed a prediction and offshore oil industry design. Cardone surface wind profile in the pressure equation.
    [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]
  • Chart Datum and Bathymetry Correction to Support Managing Coral Grouper in Lepar and Pongok Island Waters, South Bangka Regency
    ILMU KELAUTAN Desember 2018 Vol 23(4):179-186 ISSN 0853-7291 Chart Datum and Bathymetry Correction to Support Managing Coral Grouper in Lepar and Pongok Island Waters, South Bangka Regency Sudirman Adibrata1,2*, Fredinan Yulianda3, Mennofatria Boer3, and I Wayan Nurjaya4 1Program of Coastal and Marine Resource Management, Bogor Agricultural University Jl. Agatis Campus IPB Darmaga Bogor 16680, Indonesia 2Program of Aquatic Resource Management, Faculty Agriculture, Fishery and Biology, Bangka Belitung Unversity Jl. Balunijuk Merawang District, Bangka, Bangka Belitung, Indonesia 3Department of Aquatic Resource Management, Fisheries and Marine Science Faculty, Bogor Agricultural University; Jl. Agatis Campus IPB Darmaga Bogor 16680, Indonesia 4Department of Marine Science and Technology, Fisheries and Marine Science, Bogor Agricultural University, Jl. Agatis Campus IPB Darmaga Bogor 16680, Indonesia Email: [email protected] Abstract Corrected bathimetry data is highly required to improve the quality of sea floor map, for a range of purposes including coastal environmental monitoring and management. This research was aimed to know chart datum values used for correctting bathymetry data at Bar-cheeked coral trout grouper (Plectropomus maculates) fishing ground in Lepar and Pongok Island waters 02o57’00”S and 106o50’00”E and 02o53’00”S and 107o03’00”E, respectively, South Bangka Regency, Indonesia. The study was carried out from November 2016 to October 2017, tidal data used for 15 days from September 16–30, 2017 using simple random sampling technique with the total of 845 points of measurements. To calculate tyde harmonic constituents values this study employed admiralty method resulting 10 major components. Results of this research indicated that harmonic coefficient values of M2, M2, S2, N2, K1, O1, M4, MS4, K2, and P1, were 0.0345 m, 0.0608 m, 0.0276 m, 0.4262 m, 0.2060 m, 0.0119 m, 0.0082 m, 0.0164 m, and 0.1406 m, respectively.
    [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]
  • Coastal Tide Gauge Tsunami Warning Centers
    Products and Services Available from NOAA NCEI Archive of Water Level Data Aaron Sweeney,1,2 George Mungov, 1,2 Lindsey Wright 1,2 Introduction NCEI’s Role More than just an archive. NCEI: NOAA's National Centers for Environmental Information (NCEI) operates the World Data Service (WDS) for High resolution delayed-mode DART data are stored onboard the BPR, • Quality controls the data and Geophysics (including tsunamis). The NCEI/WDS provides the long-term archive, data management, and and, after recovery, are sent to NCEI for archive and processing. Tide models the tides to isolate the access to national and global tsunami data for research and mitigation of tsunami hazards. Archive gauge data is delivered to NCEI tsunami waves responsibilities include the global historic tsunami event and run-up database, the bottom pressure recorder directly through NOS CO-OPS and • Ensures meaningful data collected by the Deep-ocean Assessment and Reporting of Tsunami (DART®) Program, coastal tide gauge Tsunami Warning Centers. Upon documentation for data re-use data (analog and digital marigrams) from US-operated sites, and event-specific data from international receipt, NCEI’s role is to ensure • Creates standard metadata to gauges. These high-resolution data are used by national warning centers and researchers to increase our the data are available for use and enable search and discovery understanding and ability to forecast the magnitude, direction, and speed of tsunami events. reuse by the community. • Converts data into standard formats (netCDF) to ease data re-use The Data • Digitizes marigrams Data essential for tsunami detection and warning from • Adds data to inventory timeline the Deep-ocean Assessment and Reporting of to ensure no gaps in data Tsunamis (DART®) stations and the coastal tide gauges.
    [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]
  • SC1 Some Comments on 'Bardsey – an Island in a Strong Tidal Stream
    SC1 Some comments on ’Bardsey – an island in a strong tidal stream Underestimating coastal tides due to unresolved topography’ by Green and Pugh I am not the topical editor or one of the reviewers for this paper, but I gave it a read and have some detailed comments that I hope are useful. I thought it was an interesting paper but the text is not very good and there are many minor problems, especially in the first half. I list these below. I will leave the official reviewers to comment more on the science. 19, 21, 24, 25 and many other places in the text - there are often mentions of ’altimeter data’ or ’altimetry database’ but the authors do not use that but instead use the outputs of a hydrodynamic tide model (TPXO9) in which altimeter data (and possibly tide gauge data) have been assimilated. There is a difference between these things and ’altimeter data’ is a complete misnomer. On the other hand, sometimes the language is correct e.g. line 18 ’altimetry constrained product’. Fine. - Corrected to “altimetry constrained product” or, more specifically, “TPXO9” throughout. Also everyone knows that altimetry has a coarse spatial (and temporal) sampling and provides elevations and not currents. But on line 14 we read about tidal streams and next line says they will be unresolved by altimetry. Well, yes, of course they will, whatever the spatial resolution. - This sentence (on line 19) has been rewritten: “…and that even in this latest [TPXO9] altimetry constrained product the derived tidal stream is seriously under-represented due to the island not being resolved.” So I think the text has to be gone through and the misleading language corrected.
    [Show full text]
  • IHO-TWCWG Inventory of Tide Gauges and Current Meters Used by Member States – Correct to 13 June 2018
    IHO-TWCWG Inventory of Tide gauges and Current meters used by Member States – Correct to 13 June 2018 Long Term (National 3 Analogue gauges type A- Operated by the Hydrographic Service of the Algerian Navy. Float gauges recording to paper. Algeria Network) OTT-R16 Digital gauges not yet installed and there is no real time data transmission. Casey, Davi and Mawson Pressure 600-kg concrete moorings containing gauges in areas relatively free of icebergs have operated Stations for eight years at Mawson and Davis and at Casey for five. A new shore gauge at Mawson Antarctica will use an inclined borehole to the sea, heated to stop the water from freezing. (Australia) Macquarie Island Acoustic and Pressure Access to the sea was gained via an inclined bore hole, with the gauge and electronics in a sealed fibre glass dome at the top of the hole SEAFRAME Operated by Bureau of Meteorology, Australia. Long Term (National Electromagnetic Tide Pole, Please see www.icsm.gov.au Network) Acoustic, Float, Pressure, publication “Australian Tides Manual” State Operated- Bubbler, Radar (in most Australia cases Vegapuls), Gas purge, For details of which type deployed where. Radar with Shaft encoder As most of the permanent gauges are installed by other Agencies details can be sought. InterOcean S4 Pressure Short Term (AHS) gauge Bottom mounted and usually installed with a tide staff Or RBR TGR-1050 Mina’ Salman at HSD The whole system was installed May – June 2014 and is still under trial especially with data Jetty. Network connected transfer to SLRB’s database. Therefore the BTN system has not yet been released for public to web base hosted by SLRB.
    [Show full text]
  • V32n04 1991-04.Pdf (1.129Mb)
    NEWSLETTER WOODS HOLE OCEANOGRAPHlC INSTITUTION APRIL 1991 DSL christens new JASON testbed HYLAS, a new shallow-water ROV (rerrotely operated vehicle) was S christened with a bottle of cham­ pagne last month at the Coastal Research Lab (CRL) tank. A Like other vehicles developed by l WHOl's Deep Submergence Lab, HYLAS gets its name from a figure in Greek mythology. The tradition started when Bob Ballard named JASON after the legendary seeker of the Golden Fleece. DSL's Nathan Ulrich was responsible for naming HYLAS. According to myth, Hylas was an Argonaut and the pageboy 01 Her­ cules. When the ARGO stopped on the way to retrieve the Golden Fleece, Hylas was sent for water. A nymph at the spring thought he was so beautifullhat she came from the DSL Staff Assistant Anita Norton christens HYLAS by pouring champagne water, wrapped her arms around him, over it in the Coastal Research Lab tank. and dragged him down into the pool to live with her forever. Hercules was designed to be compatible with those JASON precisely in the critical areas so upset that he wandered off into on JASON. JASON's manipulator that will be used for testing, the the forest looking for Hylas, and was arm and electronics will be used on testbed vehicle was built ~ss expen­ left behind when Jason and the initial experiments with HYLAS to test sively. For instance, HYLAS uses ARGO put to sea. methods of vehicle/manipulator light, inexpensive foam instead of the Like its namesake, the ROV control. An improved manipulator costly syntactic foam used on HYLAS will spend its life in a pool.
    [Show full text]
  • Annual Sea Level Amplitude Analysis Over the North Pacific Ocean Coast by Ensemble Empirical Mode Decomposition Method
    remote sensing Technical Note Annual Sea Level Amplitude Analysis over the North Pacific Ocean Coast by Ensemble Empirical Mode Decomposition Method Wen-Hau Lan 1 , Chung-Yen Kuo 2 , Li-Ching Lin 3 and Huan-Chin Kao 2,* 1 Department of Communications, Navigation and Control Engineering, National Taiwan Ocean University, Keelung 20224, Taiwan; [email protected] 2 Department of Geomatics, National Cheng Kung University, Tainan 70101, Taiwan; [email protected] 3 Department of System Engineering and Naval Architecture, National Taiwan Ocean University, Keelung 20224, Taiwan; [email protected] * Correspondence: [email protected]; Tel.: +886-06-275-7575 (ext. 63833-818) Abstract: Understanding spatial and temporal changes of seasonal sea level cycles is important because of direct influence on coastal systems. The annual sea level cycle is substantially larger than semi-annual cycle in most parts of the ocean. Ensemble empirical mode decomposition (EEMD) method has been widely used to study tidal component, long-term sea level rise, and decadal sea level variation. In this work, EEMD is used to analyze the observed monthly sea level anomalies and detect annual cycle characteristics. Considering that the variations of the annual sea level variation in the Northeast Pacific Ocean are poorly studied, the trend and characteristics of annual sea level amplitudes and related mechanisms in the North Pacific Ocean are investigated using long-term tide gauge records covering 1950–2016. The average annual amplitude of coastal sea level exhibits interannual-to-decadal variability within the range of 14–220 mm. The largest value of ~174 mm is observed in the west coast of South China Sea.
    [Show full text]