DYNAMICS OF OCEAN TIDES OCEANOGRAPHIC SCIENCES LIBRARY VOLUME 3 G.1. MARCHUK and B. A. KAGAN P. P. Shirshov Institute o/Oceanology, Moscow, U.S.SR. Dynamics of Ocean Tides Translated/rom the Russian by V. M. DIVID, N. N. PROTSENKO and YU. U. RAJABOV Kluwer Academic Publishers Dordrecht I Boston I London Library of Congress Cataloging in Publication Data Marchuk, G. 1. (Gur;! 1vanovich), 1925- [Oinalllika okeanskiKh prilivov. Englishi Oynalllics of ocean tides I G.1. Marchuk and B.A. Kagan. p. c~. -- (Oceanographic sciences library) Translation of: Oinalllika okeanskikh prilivov. Bibliography: p. Inc 1u des index. ISBN 90-277-2552-7 1. Tides. I. Kagan, B. A. (Boris Abralllovich) II. Title. III. Series: Oceanographic sciences library (Kluwer Acadelllic Pub 11 shers ) GC301.2.M3713 1989 551.47·08--dc20 89-8049 ISBN-13: 978-94-010-7661-6 e-ISBN-13: 978-94-009-2571-7 DOl: 10.1007/978-94-009-2571-7 Translated from the 1983 Russian edition of .1lHHAMHKA OKEAHCKHX nPHJlI1BOB published by Gidrometeoizdat, Leningrad. Published by Kluwer Academic Publishers, P.O. Box 17,3300 AA Dordrecht, The Netherlands. Kluwer Academic Publishers incorporates the publishing programmes of D. Reidel, Martinus Nijhoff, Dr W. Junk and MTP Press. Sold and distributed in the U.S.A. and Canada by Kluwer Academic Publishers, 101 Philip Drive, Norwell, MA 02061, U.S.A. In all other countries, sold and distributed by Kluwer Academic Publishers Group, P.O. Box 322, 3300 AH Dordrecht, The Netherlands. All Rights Reserved © 1989 by Kluwer Academic Publishers Softcover reprint of the hardcover lst edition 1989 No part of the material protected by this copyright notice may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without written permission from the copyright owner. TABLE OF CONTENTS FOREWORD TO THE RUSSIAN EDITION ix FOREWORD TO THE ENGLISH EDmON xi CHAPTER 1: TIDAL POTENTIAL 1 1.1. The Tide-Generating Forces in the Ocean 1 1.2. Tidal Potential 4 1.3. Harmonie Analysis of the Tidal Potential 7 1.4. Additional Potentials of Deformation 12 CHAPTER 2: METHODS AND RESULTS OF EXPERIMENTAL STUDIES OF OCEAN TIDES 18 2.1. Direct Measurements of Tidal Elevations 18 2.1.1. Semidiurnal Tides 20 2.1.2. Diurnal Tides 24 2.1.3. Long-Period Tides 26 2.1.4. The Nature of the Ocean's Response to External Action 27 2.2. Satellite Data 29 2.3. Determination of Ocean Tides from Gravimetric Data 39 CHAPTER 3: QUALITATIVE STUDIES OF THE TIDAL DYNAMICS EQUATIONS 42 3.1. Tidal Dynamics Equations 42 3.2. Simplification of the Tidal Dynamics Equations, Boundary Conditions 45 3.3. Basic Notions and Definitions 47 3.4. Uniqueness Theorem 49 3.5. A Priori Estimates 51 3.6. Existence Theorem 57 3.7. Solvability of the Three-Dimensional Boundary Value Problem of Tidal Dynamics: Homogeneous Ocean 62 3.8. Solvability of the Three-Dimensional Boundary Value Problem of Tidal Dynamics: Stratified Ocean 71 3.9. Asymptotic Behavior of the Solution of Tidal Dynamics Equations when t ...... 00 84 vi Table of Contents CHAPTER 4: FREE OSCILLATIONS IN THE WORLD OCEAN 88 4.1. Rayleigh's Ratio 88 4.2. Analytical Solutions 92 4.2.1. Spherical Ocean of Constant Depth 93 4.2.2. Ocean Bounded by Two Meridians 95 4.2.3. A Flat Basin 98 4.3. Numerical Solutions 100 4.3.1. Proudman's Method 102 4.3.2. Finite Difference Method 104 4.3.3. Results 107 4.4. Elementary Modes of Free Oscillations 112 4.4.1. Sverdrup Waves 114 4.4.2. Kelvin Waves 118 4.4.3. Poincare Waves 122 CHAPTER 5: FORCED TIDAL OSCILLATIONS IN THE WORLD OCEAN 128 5.1. Analytical Solutions 128 5.2. Numerical Solutions 135 5.2.1. The Semi-Emperical Approach 135 5.2.2. The Theoretical Approach 136 5.2.3. Semidiurnal Tides 137 5.2.4. Diurnal Tides 141 5.2.5. Long-Period Tides 142 5.3. Numerical Experiments 144 5.3.1. Tides in the World Ocean of Real Configuration 144 5.3.2. Tides in the World Ocean of Idealized Configuration 144 5.3.3. Tides in the Oceans Separated by Barriers 147 5.3.4. Tides in the World Ocean in the Absence of the Earth's Rotation 148 CHAPTER 6: TIDES IN THE OCEAN-SHELF SYSTEM 151 6.1. Preliminary Remarks 151 6.2. The Existing Methods of Shelf-Effect Parameterization 153 6.2.1. Local Methods of Parameterization 153 6.2.2. Integral Approaches to Parameterization 160 6.3. The Influence of Shelf Effects on the Tides in an Idealized Ocean 164 6.4. The Influence of Shelf Effects on the Tides in the World Ocean 174 CHAPTER 7: GLOBAL INTERACTION OF OCEAN AND TERRESTRIAL TIDES 1M 7.1. Solvability Conditions of the Problem 184 7.2. Difference Methods of Solution 186 7.3. Results of Numerical Experiments 192 7.3.1. Ocean Tides 192 Table of Contents vii 7.3.2. Terrestrial Tides 194 7.3.3. Tidal Variations of Gravity 198 CHAPTER 8: ENERGETICS OF OCEAN TIDES 205 8.1. Energy Equation 205 8.2. Astronomical, Geophysical, and Satellite Estimations of Tidal Energy Dissipation 207 8.2.1. Astronomical Estimations 207 8.2.2. Geophysical Estimations 213 8.2.3. Satellite Estimations 219 8.3. The Problem of Tidal Energy Dissipation in the Ocean-Earth System 223 8.4. Tidal Energy Dissipation in the Paleoocean 229 CHAPTER 9: BOTTOM BOUNDARY LAYER IN TIDAL FLOW: EXPERIMENTAL DATA 235 9.1. Motion Regime in the Bottom Boundary Layer 235 9.1.1. The Method of Small Perturbations 236 9.1.2. The Energy Method 240 9.2. Hydrodynamic Properties of the Sea Bottom 244 9.3. Mean Velocity Profiles 247 9.4. Statistical Characteristics of Turbulent Fluctuations 253 9.5. Unidimensional and Co-Spectra of Velocity Fluctuations, Reynolds Stress 259 9.6. Similarity of Turbulence Structures in Boundary Layers of Different Origin 264 CHAPTER 10: BOTTOM BOUNDARY LAYER IN TIDAL FLOW: THEORETICAL MODELS 266 10.1. Qualitative Considerations Regarding the Vertical Distribution of the Tidal Velocity in the Bottom Boundary Layer 266 10.2. Bottom Boundary Layer Models Based on A Priori Assignment of the Vertical Turbulent Viscosity Coefficient 268 10.3. Bottom Boundary Layer Models Based on the Closure of Equations with the Help of Semi-Emperical Hypotheses 274 10.3.1. Bottom Boundary Layer with Neutral Stratification 275 10.3.2. Stratified Bottom Boundary Layer 285 10.4. The Resistance Law in Tidal Flow 295 10.4.1. Jonsson's Solution 298 10.4.2. Kajiura's Solution 301 10.4.3. Kagan's Solutions 304 REFERENCES 309 INDEX 325 FOREWORD TO TIlE RUSSIAN EDITION Applications of ocean-tide information have expanded considerably in recent years. These data are now being used not only to solve vital problems in oceanography, but also, in the adjacent fields of geophysics, to study earth tides, elastic properties of the Earth's crust and tidal gravity variations. They are also used, in space stu dies to calculate the trajectories of man-made satellites of the Earth and to inter pret the results of satellite measurements. New prospects have also opened up for the use of data on tidal currents. Even now, the shelf zones are intensively utilized, and there are plans to com mence, in the near future, the construction of major industrial structures such as nuclear reactors, oil storage facilities and ports. Next in turn is the prospecting for oil and gas on the floor of the open ocean, which entails performing deep-sea dril ling and organizing oil and gas production, storage and transportation. The neces sity of appraising the possible economic, social and ecological consequences of all these projects imposes increasingly stringent demands on the comprehensiveness and accuracy of information concerning tides and tidal currents. These demands were partially taken into account in the program of deep-sea tidal measurements, prepared in 1966 by Working Group No. 27 of the Scientific Committee on Ocean Research (SCOR). This program invisaged the recording of tidal elevations on a network of stations covering the deep part of the open ocean and the continental slope region. Seventeen years have passed, but the end of the work is not in Sight. Satellite measurements seem to be the only source of new empirical ocean-tide data to be realistically contemplated in future. Observations of the perturbations in satellite orbit elements now make it pos sible to determine the parameters of the second spherical harmonic of ocean tides. This is sufficient to estimate the global dissipation of tidal energy but not enough to reproduce the tidal pattern in the World Ocean. In the latter case, the use of satellite altimetry may prove to be highly successful; but here, unfortunately, things are not as simple as one would wish them to be. Firstly, the tidal elevations usually observed in the open ocean lie within the limits of error in determining the mean ocean level. Secondly, satellite trajectories vary in space, so that a continuous series of measurements cannot be obtained for a fixed point but only for a certain region in its vicinity. Thirdly, the possibilities of satellite altimetry are limited by the accuracy of determining satellite orbits. Consequently, in the accuracy of measurements, satellite altimetry is still inferior to deep-sea and standard observa tions of tidal level oscillations. It is, however, vastly superior for conducting x Foreword to the Russian Edition extensive measurements in the open ocean and, therefore, is the method that will be used in the future. So far, almost all information on the open ocean tides is obtained from calcu lations based on more or less trustworthy theoretical models. Quite understand ably the quality of these calculations is to a considerable extent, determined by the comprehensiveness and accuracy of the description of the numerous factors taking part in the formation of the phenomenon in question and, therefore, by the general level of the development of theory. Noticeable progress has been made in recent years in elaborating the theory of ocean tides. In this connection we should like to mention the solution of the prob lem of global interaction between ocean and terrestrial tides. Important steps have been made in solving the problem of the parameterization of shelf effects, which has become the stumbling block of every attempt at a numerical simulation of ocean tides. The spectral problem of the World Ocean of the real configuration is now solved, which has at last made it possible to give an exhaustive answer to the question regarding the nature of ocean tides. Investigations in the benthic boundary layer of the ocean have been developed further. The structure of the benthic boundary layer produces a significant effect on the dynamics of the ocean as a whole: it is through this layer that the thermal and dynamical interaction between the water mass and the underlying ocean bottom is realized. In this layer the processes of sedimentation and sediment transport, the chemical reactions and vital activity of benthal organisms are taking place. These processes are controlled by the dynamics of the benthic boundary layer and, in their turn, exert their influence upon it. The simplest example of such an interac tion is the relationship between the biological activity and the regime of motion in the benthic layer. The flow structure determines the conditions in the habitat of living organisms, and they, after dying off, determine the hydrodynamical proper ties of the ocean floor and its influence of the adjacent flow motion. The interrela tion between the dynamics and the ecology of the benthic layer is almost com pletely unknown at present. In this book we have tried to present systematically the current state of knowledge on ocean tides and, after a critical interpretation, to focus attention on questions as yet unsolved, the purposeful and systematic study of which would faCilitate a speedy progress in ascertaining the dynamics of ocean tides - an impor tant and intensively developing component part of the science of the ocean. We are sincerely grateful to S.S. Voit, Ye.N. Dvorkin, A.V. Nekrasov, and A.S. Sarkisyan for their valuable comments, and to V.B. Zalesny for his participation in writing Sections 3.7 - 3.9. January, 1982. G.I. MARCHUK. B.A. KAGAN FOREWORD TO TIlE ENGLISH EDITION Six years have passed since this book was written. These years have been marked by rapid progress in theoretical and experimental studies of ocean tides and by the expansion of their applications, particularly in satellite navigation and space geo desy. In their turn, improvements in the methods of space navigation and space geodesy have resulted in the development of new technology to obtain empirical information and in the ever-increasing use of the data of satellite altimetry. Apart of this purely experimental aspect, comprehensively discussed in the publications of recent years, important results have also been obtained in the field of the theory of ocean tides. These are, firstly, the solution of the problem that has remained in the background for a long time, regarding the parameterization of soli tary islands, island chainS, and archipelagoes, secondly, the conclusion of the investigations into the global interaction of oceanic and atmospheric gravitational tides and the establishment of the nature of the latter; thirdly, intensive develop ment of investigations into the vertical structure of tidal flow, based on the high level models in the hierarchy of the planetary boundary-level models, fourthly, the appearance of the results produced by modelling the evolution of the spectrum of natural oscillations and global tides in the Paleoocean and their use in construct ing the theory of the tidal evolution of the Earth-Moon system; and, finally, the development of new combined methods to calculate the global ocean tides. It is this latter point that we should like to dwell on in greater detail. It is well known that the scarcity of initial empirical data results in the World Ocean tides being most often appraised by the results of numerical model ling. This situation will possibly change only in the future, when the traditional terrestrial measurements of the level are replaced by satellite altimetry. Even this, however, will be unable to do without the results of the numerical modelling of ocean tides. This is so because the accuracy of isolating the legitimate signal from the data of altimetric measurements depends on a priori information on ocean tides; and, even if the required accuracy is reached, it will still be necessary to interpolate the altimetric measurement data between the far spaced intersection points of satellite trajectories. The future progress in describing the ocean tides is therefore modelling results and the altimetric and terrestrial (coastal, insular, deep-sea) level measurement data. The data of terrestrial measurements are not by chance mentioned here. The matter is that level perturbations, obtained with the help of satellite altimetry, constitute a small difference between larger quantities (the altitude of the