Swell and Wave Forecasting
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Dispersion of Tsunamis: Does It Really Matter? and Physics and Physics Discussions Open Access Open Access S
EGU Journal Logos (RGB) Open Access Open Access Open Access Advances in Annales Nonlinear Processes Geosciences Geophysicae in Geophysics Open Access Open Access Nat. Hazards Earth Syst. Sci., 13, 1507–1526, 2013 Natural Hazards Natural Hazards www.nat-hazards-earth-syst-sci.net/13/1507/2013/ doi:10.5194/nhess-13-1507-2013 and Earth System and Earth System © Author(s) 2013. CC Attribution 3.0 License. Sciences Sciences Discussions Open Access Open Access Atmospheric Atmospheric Chemistry Chemistry Dispersion of tsunamis: does it really matter? and Physics and Physics Discussions Open Access Open Access S. Glimsdal1,2,3, G. K. Pedersen1,3, C. B. Harbitz1,2,3, and F. Løvholt1,2,3 Atmospheric Atmospheric 1International Centre for Geohazards (ICG), Sognsveien 72, Oslo, Norway Measurement Measurement 2Norwegian Geotechnical Institute, Sognsveien 72, Oslo, Norway 3University of Oslo, Blindern, Oslo, Norway Techniques Techniques Discussions Open Access Correspondence to: S. Glimsdal ([email protected]) Open Access Received: 30 November 2012 – Published in Nat. Hazards Earth Syst. Sci. Discuss.: – Biogeosciences Biogeosciences Revised: 5 April 2013 – Accepted: 24 April 2013 – Published: 18 June 2013 Discussions Open Access Abstract. This article focuses on the effect of dispersion in 1 Introduction Open Access the field of tsunami modeling. Frequency dispersion in the Climate linear long-wave limit is first briefly discussed from a the- Climate Most tsunami modelers rely on the shallow-water equations oretical point of view. A single parameter, denoted as “dis- of the Past for predictions of propagationof and the run-up. Past Some groups, on persion time”, for the integrated effect of frequency dis- Discussions the other hand, insist on applying dispersive wave models, persion is identified. -
NANOOS Asset List 1 National Oceanic and Atmospheric
NANOOS Asset List 2008 NANOOS Asset List 1 National Oceanic and Atmospheric Administration 1.1 The CoastWatch West Coast Regional Node http://coastwatch.pfel.noaa.gov Daily – Monthly composites of satellite observations Sea Surface Temperature (GOES & POES) Ocean Color (MODIS and SeaWiFS) Ocean Winds (QuikSCAT) 1.2 The National Data Buoy Center http://seaboard.ndbc.noaa.gov/maps/Northwest.shtml 6 Minute – Hourly buoy observations Meteorological Observations (Air Temp., Pressure, Wind Speed and Direction) Ocean Observations (Water Temp., Wave Height, Period and Direction) 1.3 The Center for Operational Oceanographic Products and Services http://tidesandcurrents.noaa.gov http://opendap.co-ops.nos.noaa.gov/content 6 Minute near-shore station observations Meteorological Observations (Air Temp., Pressure, Wind Speed and Direction) Ocean Observations (Water Temp., Water Level) 1.4 NOAAWatch http://www.noaawatch.gov Information related to ongoing environmental events NOAAWatch themes include Air Quality, Droughts, Earthquakes, Excessive Heat, Fire, Flooding, Harmful Algal Blooms (HABs), Oil Spills, Rip Currents, Severe Weather, Space Weather, Tsunamis, and Volcanoes 1.5 National Weather Service http://www.weather.gov Environmental observations and forecasts Coastal and Marine Forecasts Weather Warnings 1 NANOOS Asset List 2008 Surface Pressure Maps Coastal and Marine Observations (Wind, Visibility, Sky Conditions, Temperature, Dew Point, Relative Humidity, Atmospheric Pressure, Pressure tendency) GOES Satellite Observations (Visible, -
Part II-1 Water Wave Mechanics
Chapter 1 EM 1110-2-1100 WATER WAVE MECHANICS (Part II) 1 August 2008 (Change 2) Table of Contents Page II-1-1. Introduction ............................................................II-1-1 II-1-2. Regular Waves .........................................................II-1-3 a. Introduction ...........................................................II-1-3 b. Definition of wave parameters .............................................II-1-4 c. Linear wave theory ......................................................II-1-5 (1) Introduction .......................................................II-1-5 (2) Wave celerity, length, and period.......................................II-1-6 (3) The sinusoidal wave profile...........................................II-1-9 (4) Some useful functions ...............................................II-1-9 (5) Local fluid velocities and accelerations .................................II-1-12 (6) Water particle displacements .........................................II-1-13 (7) Subsurface pressure ................................................II-1-21 (8) Group velocity ....................................................II-1-22 (9) Wave energy and power.............................................II-1-26 (10)Summary of linear wave theory.......................................II-1-29 d. Nonlinear wave theories .................................................II-1-30 (1) Introduction ......................................................II-1-30 (2) Stokes finite-amplitude wave theory ...................................II-1-32 -
NWS Melbourne Marine Web Letter August 2013 (For Marine Forecast Questions 24/7: Call 321-255-0212, Ext
NWS Melbourne Marine Web Letter August 2013 (For Marine Forecast Questions 24/7: call 321-255-0212, ext. 2) Marine Links relevant to East Central Florida Buoy 41010 It is hoped that this buoy, which went adrift in February, will be redeployed by mid to late September. Additional Marine Observations I’ve added a web page that has most of the marine observations along the east coast. http://www.srh.noaa.gov/mlb/?n=marob Note that wind/wave data became available at Sebastian Inlet via the National Data Buoy Center earlier this year. There are also some web cams with wind data. One, at Jensen Beach, has wave data too. Upwelling Some on again, off again upwelling occurred over the continental shelf this summer. This is not unusual. South to southeast winds (near shore parallel) are the primary cause of periodic upwelling. In some years, these winds are persistent and stronger than normal, which produces more prolific upwelling. In 2003, water temps in the upper 50s occurred in mid August at Daytona Beach! Typically the upwelling diminishes by late August or September. Nearshore Wave Prediction System We will soon upgrade our nearshore wave model (SWAN) to the Nearshore Wave Prediction System (NWPS). One enhancement is that Gulf Stream data will be incorporated back into the wave model. This will allow us to give better estimates for the position of the west wall of the Gulf Stream. The wave model will again be able to generate higher wave heights in the Gulf Stream during northerly wind surges. Hopefully, this functionality will be ready by Fall when cold fronts start moving through again. -
Waves and Weather
Waves and Weather 1. Where do waves come from? 2. What storms produce good surfing waves? 3. Where do these storms frequently form? 4. Where are the good areas for receiving swells? Where do waves come from? ==> Wind! Any two fluids (with different density) moving at different speeds can produce waves. In our case, air is one fluid and the water is the other. • Start with perfectly glassy conditions (no waves) and no wind. • As wind starts, will first get very small capillary waves (ripples). • Once ripples form, now wind can push against the surface and waves can grow faster. Within Wave Source Region: - all wavelengths and heights mixed together - looks like washing machine ("Victory at Sea") But this is what we want our surfing waves to look like: How do we get from this To this ???? DISPERSION !! In deep water, wave speed (celerity) c= gT/2π Long period waves travel faster. Short period waves travel slower Waves begin to separate as they move away from generation area ===> This is Dispersion How Big Will the Waves Get? Height and Period of waves depends primarily on: - Wind speed - Duration (how long the wind blows over the waves) - Fetch (distance that wind blows over the waves) "SMB" Tables How Big Will the Waves Get? Assume Duration = 24 hours Fetch Length = 500 miles Significant Significant Wind Speed Wave Height Wave Period 10 mph 2 ft 3.5 sec 20 mph 6 ft 5.5 sec 30 mph 12 ft 7.5 sec 40 mph 19 ft 10.0 sec 50 mph 27 ft 11.5 sec 60 mph 35 ft 13.0 sec Wave height will decay as waves move away from source region!!! Map of Mean Wind -
Sea State in Marine Safety Information Present State, Future Prospects
Sea State in Marine Safety Information Present State, future prospects Henri SAVINA – Jean-Michel LEFEVRE Météo-France Rogue Waves 2004, Brest 20-22 October 2004 JCOMM Joint WMO/IOC Commission for Oceanography and Marine Meteorology The future of Operational Oceanography Intergovernmental body of technical experts in the field of oceanography and marine meteorology, with a mandate to prepare both regulatory (what Member States shall do) and guidance (what Member States should do) material. TheThe visionvision ofof JCOMMJCOMM Integrated ocean observing system Integrated data management State-of-the-art technologies and capabilities New products and services User responsiveness and interaction Involvement of all maritime countries JCOMM structure Terms of Reference Expert Team on Maritime Safety Services • Monitor / review operations of marine broadcast systems, including GMDSS and others for vessels not covered by the SOLAS convention •Monitor / review technical and service quality standards for meteo and oceano MSI, particularly for the GMDSS, and provide assistance and support to Member States • Ensure feedback from users is obtained through appropriate channels and applied to improve the relevance, effectiveness and quality of services • Ensure effective coordination and cooperation with organizations, bodies and Member States on maritime safety issues • Propose actions as appropriate to meet requirements for international coordination of meteorological and related communication services • Provide advice to the SCG and other Groups of JCOMM on issues related to MSS Chair selected by Commission. OPEN membership, including representatives of the Issuing Services for GMDSS, of IMO, IHO, ICS, IMSO, and other user groups GMDSS Global Maritime Distress & Safety System Defined by IMO for the provision of MSI and the coordination of SAR alerts on a global basis. -
Sea State Effect on the Sea Surface Emissivity at L-Band
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by UPCommons. Portal del coneixement obert de la UPC IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, VOL. 41, NO. 10, OCTOBER 2003 2307 Sea State Effect on the Sea Surface Emissivity at L-Band Jorge José Miranda, Mercè Vall-llossera, Member, IEEE, Adriano Camps, Senior Member, IEEE, Núria Duffo, Member, IEEE, Ignasi Corbella, Member, IEEE, and Jacqueline Etcheto Abstract—In May 1999, the European Space Agency (ESA) temperature images will provide looks of the same pixel under selected the Earth Explorer Opportunity Soil Moisture and incidence angles from 0 to almost 65 , which requires the Ocean Salinity (SMOS) mission to obtain global and frequent soil development of soil and sea emission models in the whole moisture and ocean salinity maps. SMOS single payload is the Microwave Imaging Radiometer by Aperture Synthesis (MIRAS), range of incidence angles, and suitable geophysical parameters an L-band two-dimensional aperture synthesis radiometer with retrieval algorithms. multiangular observation capabilities. At L-band, the brightness The dielectric permittivity for seawater is determined, among temperature sensitivity to the sea surface salinity (SSS) is low, other variables, by salinity. Therefore, in principle, it is possible approximately 0.5 K/psu at 20 C, decreasing to 0.25 K/psu at to retrieve SSS from passive microwave measurements as long 0 C, comparable to that to the wind speed 0.2 K/(m/s) at nadir. However, at a given time, the sea state does not depend only as the variables influencing the brightness temperature (TB) on local winds, but on the local wind history and the presence signal (sea surface temperature, roughness, and foam) can be of waves traveling from far distances. -
Circulation-Wave Coupling with a Wave Parameterization for the Idealized California Coastal Region
Circulation-Wave Coupling With a Wave Parameterization For the Idealized California Coastal Region Le Ly and Curt Collins Dept. of Oceanography Naval Postgraduate School Monterey, CA 93043 1. Introduction atmospheric model), POM (Princeton Ocean Momentum and energy transfers across the air- Model; Blumberg and Mellor, 1987), and WAM sea interface under realistic ocean conditions are wave model (Wilczak et al., 1999), and an important not only in theoretical studies, but also atmosphere-POM-WAM for the Mediterranean in many applications including marine region (Lionello et al., 1999). atmospheric and oceanic forecasts and climate Based on a new concept of oceanic turbulence modeling on all scales. Surface breaking waves and a wave breaking condition of the linear wave are believed to be an important supplier of theory, a surface wave parameterization is turbulent energy besides shear production of the developed and presented. This wave classical turbulence theory. Waves contain a parameterization with wave-dependent roughness considerable amount of momentum and energy, is tested against available data on wave- and they redistribute these quantities over great dependent turbulence dissipation, roughness distances. Wind waves supply energy for length, drag coefficient, and momentum fluxes turbulence due to breaking. Ocean waves strongly using a coupled air-wave-sea model. We also effect the air-sea system on all scale. A part of the present a circulation-wave coupling study using a energy and momentum is transferred directly wave dependent roughness (Ly and Garwood, from the atmosphere to ocean currents while 2000) and taking the wind-wave-turbulence- another part is transferred to surface waves. The current relationship into account. -
Marine Forecasting at TAFB [email protected]
Marine Forecasting at TAFB [email protected] 1 Waves 101 Concepts and basic equations 2 Have an overall understanding of the wave forecasting challenge • Wave growth • Wave spectra • Swell propagation • Swell decay • Deep water waves • Shallow water waves 3 Wave Concepts • Waves form by the stress induced on the ocean surface by physical wind contact with water • Begin with capillary waves with gradual growth dependent on conditions • Wave decay process begins immediately as waves exit wind generation area…a.k.a. “fetch” area 4 5 Wave Growth There are three basic components to wave growth: • Wind speed • Fetch length • Duration Wave growth is limited by either fetch length or duration 6 Fully Developed Sea • When wave growth has reached a maximum height for a given wind speed, fetch and duration of wind. • A sea for which the input of energy to the waves from the local wind is in balance with the transfer of energy among the different wave components, and with the dissipation of energy by wave breaking - AMS. 7 Fetches 8 Dynamic Fetch 9 Wave Growth Nomogram 10 Calculate Wave H and T • What can we determine for wave characteristics from the following scenario? • 40 kt wind blows for 24 hours across a 150 nm fetch area? • Using the wave nomogram – start on left vertical axis at 40 kt • Move forward in time to the right until you reach either 24 hours or 150 nm of fetch • What is limiting factor? Fetch length or time? • Nomogram yields 18.7 ft @ 9.6 sec 11 Wave Growth Nomogram 12 Wave Dimensions • C=Wave Celerity • L=Wave Length • -
Basin Scale Tsunami Propagation Modeling Using Boussinesq Models: Parallel Implementation in Spherical Coordinates
WCCE – ECCE – TCCE Joint Conference: EARTHQUAKE & TSUNAMI BASIN SCALE TSUNAMI PROPAGATION MODELING USING BOUSSINESQ MODELS: PARALLEL IMPLEMENTATION IN SPHERICAL COORDINATES J. T. Kirby1, N. Pophet2, F. Shi1, S. T. Grilli3 ABSTRACT We derive weakly nonlinear, weakly dispersive model equations for propagation of surface gravity waves in a shallow, homogeneous ocean of variable depth on the surface of a rotating sphere. A numerical scheme is developed based on the staggered-grid finite difference formulation of Shi et al (2001). The model is implemented using the domain decomposition technique in conjunction with the message passing interface (MPI). The efficiency tests show a nearly linear speedup on a Linux cluster. Relative importance of frequency dispersion and Coriolis force is evaluated in both the scaling analysis and the numerical simulation of an idealized case on a sphere. 1 INTRODUCTION The conventional models in the global-scale tsunami modeling are based on the shallow water equations and neglect frequency dispersion effects in wave propagation. Recent studies on tsunami modeling revealed that such tsunami models may not be satisfactory in predicting tsunamis caused by nonseismic sources (Løvholt et al., 2008). For seismic tsunamis, the frequency dispersion effects in the long distance propagation of tsunami fronts may become significant. The numerical simulations of the 2004 Indian Ocean tsunami by Glimsdal et al. (2006) and Grue et al. (2008) indicated the undular bores may evolve in shallow water, as the phenomenon evidenced in observations (Shuto, 1985). In the simulation for the same tsunami by Grilli et al. (2007), the dispersive effects were quantified by running the dispersive Boussinesq model FUNWAVE (Kirby et al., 1998) and the NSWE solver. -
Shallow Water Waves and Solitary Waves Article Outline Glossary
Shallow Water Waves and Solitary Waves Willy Hereman Department of Mathematical and Computer Sciences, Colorado School of Mines, Golden, Colorado, USA Article Outline Glossary I. Definition of the Subject II. Introduction{Historical Perspective III. Completely Integrable Shallow Water Wave Equations IV. Shallow Water Wave Equations of Geophysical Fluid Dynamics V. Computation of Solitary Wave Solutions VI. Water Wave Experiments and Observations VII. Future Directions VIII. Bibliography Glossary Deep water A surface wave is said to be in deep water if its wavelength is much shorter than the local water depth. Internal wave A internal wave travels within the interior of a fluid. The maximum velocity and maximum amplitude occur within the fluid or at an internal boundary (interface). Internal waves depend on the density-stratification of the fluid. Shallow water A surface wave is said to be in shallow water if its wavelength is much larger than the local water depth. Shallow water waves Shallow water waves correspond to the flow at the free surface of a body of shallow water under the force of gravity, or to the flow below a horizontal pressure surface in a fluid. Shallow water wave equations Shallow water wave equations are a set of partial differential equations that describe shallow water waves. 1 Solitary wave A solitary wave is a localized gravity wave that maintains its coherence and, hence, its visi- bility through properties of nonlinear hydrodynamics. Solitary waves have finite amplitude and propagate with constant speed and constant shape. Soliton Solitons are solitary waves that have an elastic scattering property: they retain their shape and speed after colliding with each other. -
Estimation of Significant Wave Height Using Satellite Data
Research Journal of Applied Sciences, Engineering and Technology 4(24): 5332-5338, 2012 ISSN: 2040-7467 © Maxwell Scientific Organization, 2012 Submitted: March 18, 2012 Accepted: April 23, 2012 Published: December 15, 2012 Estimation of Significant Wave Height Using Satellite Data R.D. Sathiya and V. Vaithiyanathan School of Computing, SASTRA University, Thirumalaisamudram, India Abstract: Among the different ocean physical parameters applied in the hydrographic studies, sufficient work has not been noticed in the existing research. So it is planned to evaluate the wave height from the satellite sensors (OceanSAT 1, 2 data) without the influence of tide. The model was developed with the comparison of the actual data of maximum height of water level which we have collected for 24 h in beach. The same correlated with the derived data from the earlier satellite imagery. To get the result of the significant wave height, beach profile was alone taking into account the height of the ocean swell, the wave height was deduced from the tide chart. For defining the relationship between the wave height and the tides a large amount of good quality of data for a significant period is required. Radar scatterometers are also able to provide sea surface wind speed and the direction of accuracy. Aim of this study is to give the relationship between the height, tides and speed of the wind, such relationship can be useful in preparing a wave table, which will be of immense value for mariners. Therefore, the relationship between significant wave height and the radar backscattering cross section has been evaluated with back propagation neural network algorithm.