Tides in the Indonesian Seas

Total Page:16

File Type:pdf, Size:1020Kb

Tides in the Indonesian Seas or collective redistirbution of any portion article of any by of this or collective redistirbution Th THE INDONESIAN SEAS articleis has been in published A BRIEF OVERVIEW OF Oceanography , Volume 18, Number journal of Th 4, a quarterly , Volume Tides in the permitted only w is photocopy machine, reposting, means or other Indonesian Seas BY RICHARD D. RAY, GARY D. EGBERT, AND SVETLANA Y. EROFEEVA 2005 by Th e Oceanography Copyright Society. Tidal phenomena in the Indonesian Gross characteristics of the Indone- portance of tidally generated residual seas are among the most complex in the sian tides were worked out during the circulation, especially east of Sulawesi, of Th approval the ith world. Complicated coastal geometries colonial period in the early twentieth for horizontal mixing. with narrow straits and myriad small is- century. Summary descriptions of coast- Ffi eld and Gordon (1996) and Hata- lands, rugged bottom topography next to al tides were published by both Krüm- yama (2004) noted the important role gran e Oceanography is Society. All rights reserved. Permission wide shelves of shallow water, and large mel and Van der Stok in 1911, and tidal of tides in vertical mixing, a fact that or Th e Oceanography [email protected] Society. Send to: all correspondence quantities of tidal power input from the phase charts were published by Dietrich calls for development of high-resolution, adjoining Indian and Pacifi c Oceans—all during the war in 1944. Given the dif- three-dimensional tidal models in order combine to form a complex system of fi culties of collecting in situ data, it is to investigate the sources and variability interfering three-dimensional waves. worth noting that those early measure- of internal tides. Some initial steps in The seas feature multiple amphidromes ments still form the bulk of the avail- that direction are presented in this issue (points in the sea where there is zero able station data in the International by Robertson and Ffi eld. See also related tidal amplitude due to canceling of tidal Hydrographic Bureau’s tidal archives. work by Schiller (2004). waves), strong tidal currents, residual Much of that early work was subse- The charts we show here are based on circulations, internal waves, and solitons. quently recompiled and synthesized by the data-assimilation work of Egbert and ted to copy this article Repu for use copy this and research. to in teaching ted Diurnal tides are unusually strong and Wyrtki (1961), who constructed diurnal Erofeeva (2002). Data assimilation is es- are dominant along some coastlines. and semidiurnal cotidal charts based pecially attractive in regions such as the e Oceanography Society, PO Box 1931, Rockville, MD 20849-1931, USA. The tides are known to affect local mix- on all available coastal and island infor- Indonesian Archipelago where numeri- ing and circulation, but the tidal energy mation. Owing to lack of data, Wyrtki available for these processes is not yet re- could draw no contours in the adjoining Richard D. Ray ([email protected]) is liably determined. And while mapping of Indian and Pacifi c waters, but his (sub- Geophysicist, Space Geodesy Laboratory, the Indonesian tides has benefi ted mark- jective) interpolations over the region of NASA Goddard Space Flight Center, Green- edly by assimilating satellite altimeter enclosed seas were—and still are—emi- belt, MD, USA. Gary D. Egbert is Professor, measurements into numerical models, nently reasonable. College of Oceanic & Atmospheric Sciences, improvements to the energy budget will More recently, Hatayama et al. (1996) Oregon State University, Corvallis, OR, USA. blication, systemmatic reproduction, reproduction, systemmatic blication, likely require higher-resolution analyses computed two major diurnal and semi- Svetlana Y. Erofeeva is Research Associate, and a densifi ed network of satellite tidal diurnal tides with a numerical baro- College of Oceanic & Atmospheric Sciences, measurements. tropic model; they emphasize the im- Oregon State University, Corvallis, OR, USA. 74 Oceanography Vol. 18, No. 4, Dec. 2005 Figure 1. Topographic chart, 1BDJmD with isobaths drawn at 100, 200, 4PVUI$IJOB 4VMV 1000, 2000, 4000, 6000 m. Red 0DFBO lines denote the groundtracks of the Topex/Poseidon satellite. Although these tracks are too widely spaced to support a pure- $FMFCFT ly empirical mapping of the tides in this region, the satellite data provide critically valuable data for assimilation. , #PS O F P B .PMVDDBD S S J N B T B T U B B L B . +BWB #BOEB 'MPSFT PS JN 4BXV 5 5JNPS *OEJBO0DFBO "VTUSBMJB cal modeling efforts are hindered by in- inated by the large tide from the Indian the tide from the Indian Ocean, with adequate knowledge of bathymetry and Ocean, where amplitudes are well over increased amplitudes in the Flores Sea stratifi cation and by uncertainties con- a meter off northwest Australia. This and with markedly increased amplitudes cerning dissipation. Data assimilation wave is delayed slightly (about 2 hours) westward in the Java Sea. The diurnal can compensate for some of these mod- as it passes into the Banda and Flores tide propagates westward around both eling diffi culties. Our charts are based on Seas. Those seas are suffi ciently deep that the northern and southern coasts of Bor- ten years of sea-level measurements from high tide occurs almost simultaneously neo, intersecting to form a complicated the Topex/Poseidon satellite altimeter. throughout both basins. From the Banda system of large-amplitude, nearly amp- The altimeter data are used to compute Sea, the semidiurnal tide passes slowly hidromic systems west of Borneo. linearized inverse adjustments to a prior, northwards through the Molucca Sea From Figures 2 and 3 it is evident that multi-constituent, nonlinear, barotropic, region. From the Flores, it propagates the tides throughout the eastern archi- time-stepping model (for details, see slowly northwards into Makassar Strait pelago, as well as in the adjoining Pacifi c, Egbert and Erofeeva, 2002). The satellite and also westwards, but more weakly, are predominantly semidiurnal but with track pattern is shown in Figure 1. across the Java Sea. signifi cant diurnal inequality, whereas Cotidal charts of the largest semidi- The diurnal tide, in contrast to the the tides west of about 118°E are mixed urnal tide M2 and diurnal tide K1 are semidiurnal, passes southwards through diurnal, and west of Borneo almost shown in Figures 2 and 3, respectively. Makassar Strait and Molucca Sea. In the wholly diurnal. The large M2 amplitude The semidiurnal response is clearly dom- Banda and Flores Seas this wave meets on the coast of west-northwest Borneo is Oceanography Vol. 18, No. 4, Dec. 2005 75 a localized shelf resonance, but not well most part, with shallow water giving Timor and in the Molucca Sea and its determined because it falls almost per- rise to rapid currents. A few exceptions boundaries. These are regions of intense fectly between two satellite tracks. where relatively strong currents appear barotropic energy fl uxes, as can be seen The M2 tidal current velocities, shown in deeper water are along the southern explicitly in Figure 5. Figure 6 shows in Figure 4, refl ect bathymetry for the and northern coasts of the island of similar fl uxes for K1. These diagrams re- Figure 2. Amplitude (top) and Green- wich phase lags (bottom) of the M2 tide, based on assimilation of ten years of Topex/Poseidon satellite altimetry into a nonlinear hydrodynamic model (Egbert and Erofeeva, 2002). Phase-lag contour interval is 30°, equivalent to . 1 lunar hour. Inverse theoretic error estimates suggest that these charts are accurate to a few centimeters, except in a few high-amplitude locations that fall between satellite tracks (e.g., the large tides on the west coast of Borneo and off Australia). DN 76 Oceanography Vol. 18, No. 4, Dec. 2005 inforce the notion that the Indian Ocean What becomes of all this tidal energy the estimated tidal dissipation in the tide governs the regional energetics of in the Indonesian seas is a topic of some Indonesian region was the most poorly M2, and the Pacifi c governs K1. The baro- importance, but dissipation estimates are determined of any region in the world tropic M2 fl uxes either side of Timor are not well determined. In fact, in the global oceans, with estimates for M2 ranging very large, exceeding 500 kW m-1. compilation by Egbert and Ray (2001), from 20 GW to 250 GW. A somewhat de- Figure 3. Amplitude (top) and Green- wich phase lags (bottom) of the diur- nal K1 tide. Phase-lag contour interval is 30°, equivalent to 2 sidereal hours. Th ese diurnal tides are unusually large, and they dominate the semidiurnal tides in some regions, such as the Java , Sea and much of the South China Sea (extending also into the Gulf of Th ai- land, just off the chart). DN Oceanography Vol. 18, No. 4, Dec. 2005 77 Figure 4. Maximum barotropic current velocity of M tide 2 (equivalent to length of semi- major axes of tidal current el- lipses). Note nonlinear color bar. Units are cm s-1. In general, these velocities refl ect bathymetry, with shallow water giving rise to rapid currents. Currents in the Banda, Timor, and part of the Flores Seas tend to rotate anti- clockwise; currents elsewhere are generally close to rectilinear, although the deep Pacifi c cur- rents rotate clockwise. DNT fendable upper bound is 150 GW, which budget for the energetics is of consider- REFERENCES is about 6 percent of the global total. able importance to understanding the Egbert, G.D., and S.Y. Erofeeva. 2002. Effi cient inverse modeling of barotropic ocean tides. Journal of At- The uncertainty is a refl ection of several effects of tides on circulation and mix- mospheric and Oceanic Technology 19:183-204.
Recommended publications
  • Basic Concepts in Oceanography
    Chapter 1 XA0101461 BASIC CONCEPTS IN OCEANOGRAPHY L.F. SMALL College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, Oregon, United States of America Abstract Basic concepts in oceanography include major wind patterns that drive ocean currents, and the effects that the earth's rotation, positions of land masses, and temperature and salinity have on oceanic circulation and hence global distribution of radioactivity. Special attention is given to coastal and near-coastal processes such as upwelling, tidal effects, and small-scale processes, as radionuclide distributions are currently most associated with coastal regions. 1.1. INTRODUCTION Introductory information on ocean currents, on ocean and coastal processes, and on major systems that drive the ocean currents are important to an understanding of the temporal and spatial distributions of radionuclides in the world ocean. 1.2. GLOBAL PROCESSES 1.2.1 Global Wind Patterns and Ocean Currents The wind systems that drive aerosols and atmospheric radioactivity around the globe eventually deposit a lot of those materials in the oceans or in rivers. The winds also are largely responsible for driving the surface circulation of the world ocean, and thus help redistribute materials over the ocean's surface. The major wind systems are the Trade Winds in equatorial latitudes, and the Westerly Wind Systems that drive circulation in the north and south temperate and sub-polar regions (Fig. 1). It is no surprise that major circulations of surface currents have basically the same patterns as the winds that drive them (Fig. 2). Note that the Trade Wind System drives an Equatorial Current-Countercurrent system, for example.
    [Show full text]
  • Chapter 10. Thermohaline Circulation
    Chapter 10. Thermohaline Circulation Main References: Schloesser, F., R. Furue, J. P. McCreary, and A. Timmermann, 2012: Dynamics of the Atlantic meridional overturning circulation. Part 1: Buoyancy-forced response. Progress in Oceanography, 101, 33-62. F. Schloesser, R. Furue, J. P. McCreary, A. Timmermann, 2014: Dynamics of the Atlantic meridional overturning circulation. Part 2: forcing by winds and buoyancy. Progress in Oceanography, 120, 154-176. Other references: Bryan, F., 1987. On the parameter sensitivity of primitive equation ocean general circulation models. Journal of Physical Oceanography 17, 970–985. Kawase, M., 1987. Establishment of deep ocean circulation driven by deep water production. Journal of Physical Oceanography 17, 2294–2317. Stommel, H., Arons, A.B., 1960. On the abyssal circulation of the world ocean—I Stationary planetary flow pattern on a sphere. Deep-Sea Research 6, 140–154. Toggweiler, J.R., Samuels, B., 1995. Effect of Drake Passage on the global thermohaline circulation. Deep-Sea Research 42, 477–500. Vallis, G.K., 2000. Large-scale circulation and production of stratification: effects of wind, geometry and diffusion. Journal of Physical Oceanography 30, 933–954. 10.1 The Thermohaline Circulation (THC): Concept, Structure and Climatic Effect 10.1.1 Concept and structure The Thermohaline Circulation (THC) is a global-scale ocean circulation driven by the equator-to-pole surface density differences of seawater. The equator-to-pole density contrast, in turn, is controlled by temperature (thermal) and salinity (haline) variations. In the Atlantic Ocean where North Atlantic Deep Water (NADW) forms, the THC is often referred to as the Atlantic Meridional Overturning Circulation (AMOC).
    [Show full text]
  • World Ocean Thermocline Weakening and Isothermal Layer Warming
    applied sciences Article World Ocean Thermocline Weakening and Isothermal Layer Warming Peter C. Chu * and Chenwu Fan Naval Ocean Analysis and Prediction Laboratory, Department of Oceanography, Naval Postgraduate School, Monterey, CA 93943, USA; [email protected] * Correspondence: [email protected]; Tel.: +1-831-656-3688 Received: 30 September 2020; Accepted: 13 November 2020; Published: 19 November 2020 Abstract: This paper identifies world thermocline weakening and provides an improved estimate of upper ocean warming through replacement of the upper layer with the fixed depth range by the isothermal layer, because the upper ocean isothermal layer (as a whole) exchanges heat with the atmosphere and the deep layer. Thermocline gradient, heat flux across the air–ocean interface, and horizontal heat advection determine the heat stored in the isothermal layer. Among the three processes, the effect of the thermocline gradient clearly shows up when we use the isothermal layer heat content, but it is otherwise when we use the heat content with the fixed depth ranges such as 0–300 m, 0–400 m, 0–700 m, 0–750 m, and 0–2000 m. A strong thermocline gradient exhibits the downward heat transfer from the isothermal layer (non-polar regions), makes the isothermal layer thin, and causes less heat to be stored in it. On the other hand, a weak thermocline gradient makes the isothermal layer thick, and causes more heat to be stored in it. In addition, the uncertainty in estimating upper ocean heat content and warming trends using uncertain fixed depth ranges (0–300 m, 0–400 m, 0–700 m, 0–750 m, or 0–2000 m) will be eliminated by using the isothermal layer.
    [Show full text]
  • Introduction to Oceanography
    Introduction to Oceanography Introduction to Oceanography Lecture 14: Tides, Biological Productivity Memorial Day holiday Monday no lab meetings Go to any other lab section this week (and let the TA know!) Bay of Fundy -- low tide, Photo by Dylan Kereluk, . Creative Commons A 2.0 Generic, Mudskipper (Periophthalmus modestus) at low tide, photo by OpenCage, Wikimedia Commons, Creative http://commons.wikimedia.org/wiki/File:Bay_of_Fundy_-_Tide_Out.jpg Commons A S-A 2.5, http://commons.wikimedia.org/wiki/File:Periophthalmus_modestus.jpg Tides Earth-Moon-Sun System Planet-length waves Cyclic, repeating rise & fall of sea level • Earth-Sun Distance – Most regular phenomenon in the oceans 150,000,000 km Daily tidal variation has great effects on life in & around the ocean (Lab 8) • Earth-Moon Distance 385,000 km Caused by gravity and Much closer to Earth, but between Earth, Moon & much less massive Sun, their orbits around • Earth Obliquity = 23.5 each other, and the degrees Earth’s daily spin – Seasons Photos by Samuel Wantman, Creative Commons A S-A 3.0, http://en.wikipedia.org/ wiki/File:Bay_of_Fundy_Low_Tide.jpg and Figure by Homonculus 2/Geologician, Wikimedia Commons, http://en.wikipedia.org/wiki/ Creative Commons A 3.0, http://en.wikipedia.org/wiki/ File:Bay_of_Fundy_High_Tide.jpg File:Lunar_perturbation.jpg Tides are caused by the gravity of the Moon and Sun acting on Scaled image of Earth-Moon distance, Nickshanks, Wikimedia Commons, Creative Commons A 2.5 Earth and its ocean. Pluto-Charon mutual orbit, Zhatt, Wikimedia Commons, Public
    [Show full text]
  • Exploration of the Deep Gulf of Mexico Slope Using DSV Alvin: Site Selection and Geologic Character
    Exploration of the Deep Gulf of Mexico Slope Using DSV Alvin: Site Selection and Geologic Character Harry H. Roberts1, Chuck R. Fisher2, Jim M. Brooks3, Bernie Bernard3, Robert S. Carney4, Erik Cordes5, William Shedd6, Jesse Hunt, Jr.6, Samantha Joye7, Ian R. MacDonald8, 9 and Cheryl Morrison 1Coastal Studies Institute, Louisiana State University, Baton Rouge, Louisiana 70803 2Department of Biology, Penn State University, University Park, Pennsylvania 16802-5301 3TDI Brooks International, Inc., 1902 Pinon Dr., College Station, Texas 77845 4Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, Louisiana 70803 5Department of Organismic and Evolutionary Biology, Harvard University, 16 Divinity Ave., Cambridge, Massachusetts 02138 6Minerals Management Service, Office of Resource Evaluation, New Orleans, Louisiana 70123-2394 7Department of Geology, University of Georgia, Athens, Georgia 30602 8Department of Physical and Environmental Sciences, Texas A&M – Corpus Christi, Corpus Christi, Texas 78412 9U.S. Geological Survey, 11649 Leetown Rd., Keameysville, West Virginia 25430 ABSTRACT The Gulf of Mexico is well known for its hydrocarbon seeps, associated chemosyn- thetic communities, and gas hydrates. However, most direct observations and samplings of seep sites have been concentrated above water depths of approximately 3000 ft (1000 m) because of the scarcity of deep diving manned submersibles. In the summer of 2006, Minerals Management Service (MMS) and National Oceanic and Atmospheric Admini- stration (NOAA) supported 24 days of DSV Alvin dives on the deep continental slope. Site selection for these dives was accomplished through surface reflectivity analysis of the MMS slope-wide 3D seismic database followed by a photo reconnaissance cruise. From 80 potential sites, 20 were studied by photo reconnaissance from which 10 sites were selected for Alvin dives.
    [Show full text]
  • Ocean Wind and Current Retrievals Based on Satellite SAR Measurements in Conjunction with Buoy and HF Radar Data
    remote sensing Article Ocean Wind and Current Retrievals Based on Satellite SAR Measurements in Conjunction with Buoy and HF Radar Data He Fang 1, Tao Xie 1,* ID , William Perrie 2, Li Zhao 1, Jingsong Yang 3 and Yijun He 1 ID 1 School of Marine Sciences, Nanjing University of Information Science and Technology, Nanjing 210044, Jiangsu, China; [email protected] (H.F.); [email protected] (L.Z.); [email protected] (Y.H.) 2 Fisheries & Oceans Canada, Bedford Institute of Oceanography, Dartmouth, NS B2Y 4A2, Canada; [email protected] 3 State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, State Oceanic Administration, Hangzhou 310012, Zhejiang, China; [email protected] * Correspondence: [email protected]; Tel.: +86-255-869-5697 Received: 22 September 2017; Accepted: 13 December 2017; Published: 15 December 2017 Abstract: A total of 168 fully polarimetric synthetic-aperture radar (SAR) images are selected together with the buoy measurements of ocean surface wind fields and high-frequency radar measurements of ocean surface currents. Our objective is to investigate the effect of the ocean currents on the retrieved SAR ocean surface wind fields. The results show that, compared to SAR wind fields that are retrieved without taking into account the ocean currents, the accuracy of the winds obtained when ocean currents are taken into account is increased by 0.2–0.3 m/s; the accuracy of the wind direction is improved by 3–4◦. Based on these results, a semi-empirical formula for the errors in the winds and the ocean currents is derived.
    [Show full text]
  • Ocean Circulation and Climate: an Overview
    ocean-climate.org Bertrand Delorme Ocean Circulation and Yassir Eddebbar and Climate: an Overview Ocean circulation plays a central role in regulating climate and supporting marine life by transporting heat, carbon, oxygen, and nutrients throughout the world’s ocean. As human-emitted greenhouse gases continue to accumulate in the atmosphere, the Meridional Overturning Circulation (MOC) plays an increasingly important role in sequestering anthropogenic heat and carbon into the deep ocean, thus modulating the course of climate change. Anthropogenic warming, in turn, can influence global ocean circulation through enhancing ocean stratification by warming and freshening the high latitude upper oceans, rendering it an integral part in understanding and predicting climate over the 21st century. The interactions between the MOC and climate are poorly understood and underscore the need for enhanced observations, improved process understanding, and proper model representation of ocean circulation on several spatial and temporal scales. The ocean is in perpetual motion. Through its DRIVING MECHANISMS transport of heat, carbon, plankton, nutrients, and oxygen around the world, ocean circulation regulates Global ocean circulation can be divided into global climate and maintains primary productivity and two major components: i) the fast, wind-driven, marine ecosystems, with widespread implications upper ocean circulation, and ii) the slow, deep for global fisheries, tourism, and the shipping ocean circulation. These two components act industry. Surface and subsurface currents, upwelling, simultaneously to drive the MOC, the movement of downwelling, surface and internal waves, mixing, seawater across basins and depths. eddies, convection, and several other forms of motion act jointly to shape the observed circulation As the name suggests, the wind-driven circulation is of the world’s ocean.
    [Show full text]
  • Coastal Upwelling Revisited: Ekman, Bakun, and Improved 10.1029/2018JC014187 Upwelling Indices for the U.S
    Journal of Geophysical Research: Oceans RESEARCH ARTICLE Coastal Upwelling Revisited: Ekman, Bakun, and Improved 10.1029/2018JC014187 Upwelling Indices for the U.S. West Coast Key Points: Michael G. Jacox1,2 , Christopher A. Edwards3 , Elliott L. Hazen1 , and Steven J. Bograd1 • New upwelling indices are presented – for the U.S. West Coast (31 47°N) to 1NOAA Southwest Fisheries Science Center, Monterey, CA, USA, 2NOAA Earth System Research Laboratory, Boulder, CO, address shortcomings in historical 3 indices USA, University of California, Santa Cruz, CA, USA • The Coastal Upwelling Transport Index (CUTI) estimates vertical volume transport (i.e., Abstract Coastal upwelling is responsible for thriving marine ecosystems and fisheries that are upwelling/downwelling) disproportionately productive relative to their surface area, particularly in the world’s major eastern • The Biologically Effective Upwelling ’ Transport Index (BEUTI) estimates boundary upwelling systems. Along oceanic eastern boundaries, equatorward wind stress and the Earth s vertical nitrate flux rotation combine to drive a near-surface layer of water offshore, a process called Ekman transport. Similarly, positive wind stress curl drives divergence in the surface Ekman layer and consequently upwelling from Supporting Information: below, a process known as Ekman suction. In both cases, displaced water is replaced by upwelling of relatively • Supporting Information S1 nutrient-rich water from below, which stimulates the growth of microscopic phytoplankton that form the base of the marine food web. Ekman theory is foundational and underlies the calculation of upwelling indices Correspondence to: such as the “Bakun Index” that are ubiquitous in eastern boundary upwelling system studies. While generally M. G. Jacox, fi [email protected] valuable rst-order descriptions, these indices and their underlying theory provide an incomplete picture of coastal upwelling.
    [Show full text]
  • WOODS HOLE OCEANOGRAPHIC INSTITUTION Deep-Diving
    NEWSLETTER WOODS HOLE OCEANOGRAPHIC INSTITUTION AUGUST-SEPTEMBER 1995 Deep-Diving Submersible ALVIN WHOI Names Paul Clemente Sets Another Dive Record Chief Financial Officer The nation's first research submarine, the Deep Submergence Paul CI~mente, Jr., a resident of Hingham Vehicle (DSV) Alvin. passed another milestone in its long career and former Associate Vice President for September 20 when it made its 3,OOOth dive to the ocean floor, a Financial Affairs at Boston University, as· record no other deep-diving sub has achieved. Alvin is one of only sumed his duties as Associate Director for seven deep-diving (10,000 feet or more) manned submersibles in the Finance and Administration at WHOI on world and is considered by far the most active of the group, making October 2. between 150 and 200 dives to depths up to nearly 15,000 feet each In his new position Clemente is respon· year for scientific and engineering research . sible for directing all business and financial The 23-1001, three-person submersible has been operated by operations of the Institution, with specifIC Woods Hole Oceanographic Institution since 1964 for the U.S. ocean resp:>nsibility for accounting and finance, research community. It is owned by the OffICe of Naval Research facilities, human resources, commercial and supported by the Navy. the National Science Foundation and the affairs and procurement operations. WHOI, National Oceanic and Atmospheric Administration (NOAA). Alvin the largest private non· profit marine research and its support vessel, the 21 0-100t Research Vessel Atlantis II, are organization in the U.S., has an annual on an extended voyage in the Pacific which began in January 1995 operating budget of nearly $90 million and a with departure from Woods Hole.
    [Show full text]
  • Deep Ocean Wind Waves Ch
    Deep Ocean Wind Waves Ch. 1 Waves, Tides and Shallow-Water Processes: J. Wright, A. Colling, & D. Park: Butterworth-Heinemann, Oxford UK, 1999, 2nd Edition, 227 pp. AdOc 4060/5060 Spring 2013 Types of Waves Classifiers •Disturbing force •Restoring force •Type of wave •Wavelength •Period •Frequency Waves transmit energy, not mass, across ocean surfaces. Wave behavior depends on a wave’s size and water depth. Wind waves: energy is transferred from wind to water. Waves can change direction by refraction and diffraction, can interfere with one another, & reflect from solid objects. Orbital waves are a type of progressive wave: i.e. waves of moving energy traveling in one direction along a surface, where particles of water move in closed circles as the wave passes. Free waves move independently of the generating force: wind waves. In forced waves the disturbing force is applied continuously: tides Parts of an ocean wave •Crest •Trough •Wave height (H) •Wavelength (L) •Wave speed (c) •Still water level •Orbital motion •Frequency f = 1/T •Period T=L/c Water molecules in the crest of the wave •Depth of wave base = move in the same direction as the wave, ½L, from still water but molecules in the trough move in the •Wave steepness =H/L opposite direction. 1 • If wave steepness > /7, the wave breaks Group Velocity against Phase Velocity = Cg<<Cp Factors Affecting Wind Wave Development •Waves originate in a “sea”area •A fully developed sea is the maximum height of waves produced by conditions of wind speed, duration, and fetch •Swell are waves
    [Show full text]
  • Indonesian Marine Fisheries Development and Strategy Under Extended Maritime Jurisdiction
    East-West Environment and Policy Institute Research Report No. 13 Indonesian Marine Fisheries Development and Strategy under Extended Maritime Jurisdiction by Salvatore Comitini Sutanto Hardjolukito East-West Center Honolulu, Hawaii THE EAST-WEST CENTER is an educational institution established in Hawaii in 1960 by the United States Congress. The Center's mandate is "to promote better relations and understanding among the nations of Asia, the Pacific, and the United States through cooperative study, training, and research." Each year more than 1,500 graduate students, scholars, professionals in business and government, and visiting specialists engage in research with the Center's interna• tional staff on major issues and problems facing the Asian and Pacific region. Since 1960, more than 30,000 men and women from the region have participated in the Center's cooperative programs. The Center's research and educational activities are conducted in five institutes- Communication, Culture Learning, Environment and Policy, Population, and Re• source Systems—and in its Pacific Islands Development Program, Open Grants, and Center-wide programs. Although principal funding continues to come from the U.S. Congress, more than 20 Asian and Pacific governments, as well as private agencies and corporations, have provided contributions for program support. The East-West Center is a public, nonprofit corporation with an international board of governors. THE EAST-WEST ENVIRONMENT AND POLICY INSTITUTE was established in October 1977 to increase understanding of the interrelationships among policies designed to meet a broad range of human and societal needs over time and the nat• ural systems and resources on which these policies depend or impact.
    [Show full text]
  • In Wind and Ocean Currents
    PAPERS IN PHYSICAL OCEANOGRAPHY AND METEOROLOGY PUBLISHED BY MASSACHUSETTS INSTITUTE OF TECHNOLOGY AND WOODS HOLE OCEANOGRAPHIC INSTITUTION (In continuation of Massachusetts Institute of Technology Meteorological Papers) VOL. III, NO.3 THE LAYER OF FRICTIONAL INFLUENCE IN WIND AND OCEAN CURRENTS BY c.-G. ROSSBY AND R. B. MONTGOMERY Contribution No. 71 from the Woods Hole Oceanographic Institution .~ J~\ CAMBRIDGE, MASSACHUSETTS Ap~il, 1935 CONTENTS i. INTRODUCTION 3 II. ADIABATIC ATMOSPHERE. 4 1. Completion of Solution for Adiabatic Atmosphere 4 2. Light Winds and Residual Turbulence 22 3. A Study of the Homogeneous Layer at Boston 25 4. Second Approximation 4° III. INFLUENCE OF STABILITY 44 I. Review 44 2. Stability in the Boundary Layer 47 3. Stability within Entire Frictional Layer 56 IV. ApPLICATION TO DRIFT CURRENTS. 64 I. General Commen ts . 64 2. The Homogeneous Layer 66 3. Analysis of Material 67 4. Results of Analysis . 69 5. Scattering of the Observations and Advection 72 6. Oceanograph Observations 73 7. Wind Drift of the Ice 75 V. LENGTHRELATION BETWEEN THE VELOCITY PROFILE AND THE VALUE OF THE85 MIXING ApPENDIX2.1. StirringTheoretical in Shallow Comments . Water 92. 8885 REFERENCESSUMMARYModified Computation of the Boundary Layer in Drift Currents 9899 92 1. INTRODUCTION The purpose of the present paper is to analyze, in a reasonably comprehensive fash- ion, the principal factors controlling the mean state of turbulence and hence the mean velocity distribution in wind and ocean currents near the surface. The plan of the in- vestigation is theoretical but efforts have been made to check each major step or result through an analysis of available measurements.
    [Show full text]