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Stochastic modeling of ocean dynamics
272 The translation is perfectly adequate, though one suspects that the style has suffered a little. Production is excellent with good diagrams, of proper size, well documented and laid out. J.S.A. GREEN (Norwich, Gt.Britain)
Stochastic Modeling of Ocean Dynamics. I.E. Timchenko. Translated from Russian by E.T. Premuzic. Harwood Academic Publishers, New York, 1984, viii + 311 pp., US$ 135.00, hardback. It is commendable that Dr Timchenko recognized quite early the need to combine dynamics, data acquisition and statistics of uncertainty in a systematic way as an important part of the maturing s~ience of oceanology. The need for such research, bringing in aspects of control and information theory, is becoming more widely appreciated. Dr Timchenko is to be credited with the foresight to prepare a monograph in this area. Discussion of a number of actual field applications enhances the work. Perhaps because of the importance of these topics, I found the book frustrating. Much as one may sympathize with the author's viewpoint, lengthy philosophical advertisements prove quite repetitive throughout the text. On the other side, important technical discussions can be terse to the point of undefined. More grievous is that the English production of the book is flawed throughout. Simpler errors of translation are only amusing, as the 'derivatization' of 'impartial equations', the 'inertion' of the 'turbulency' or the use of 'optical filter equations'. The greater difficulty is with garbled text in the course of technical development. Attempting tb circumvent text by proceeding from equation to equation, there appear to be mathematical errors, apart from typographic errors which also occur in equations. But it is difficult to say if errors are present in mathematical logic or if there's only ambiguity because some logical operations are recounted in garbled text. Symbols in equations sometimes differ from the symbols used in adjacent text. I don't know to what extent these difficulties occur in the original text or arise in translation and production. A feature of the text is discussion of field applications, particularly from the POLYMODE experiment and from a Bay of Lyons survey. Here, however, it is regrettable that figure labels are sometimes inadequate to identify what is plotted. Text suggests further confusion, as when POLYMODE zonal velocity spectra are described as limited to one minute periods. An item which may be significant but which is not addressed is the fidelity of numerical discretizations of partial differential equations. Results may depend upon aspects of finite differencing but specific methods and quality control are not described. Instead one encounters worrisome remarks
273 such as a calculation dependent upon 'utilization of a non-apparent scheme'. A point to mention is the reference list which may include items not widely known. Overall my view is that a reader seeking to learn about this field will be left frustrated. An advanced researcher thoroughly acquainted with the field may find an interesting challenge to interpret the book, likely uncovering some valuable points. G R E G HOLLOWAY (Sidney, B.C., Canada)
Ocean Wave Modeling. The SWAMP Group. Plenum Press, New York, 1985, vi + 256 pp., US$ 49.50, hardback. Accurate forecasting of wind waves has long been a major concern of the ocean engineer. In recent years, the availability of large computers and the considerable progress made in the understanding of the physics of wind waves have led to the elaboration of numerical models which allow calculation of waves over broad oceanic areas. Such models have been developed in many countries and adapted to local conditions. Each model is based on some compromise between operational requirements, such as speed of calculation, and the need to describe the physics of wave generation, interactions and dissipation as accurately as possible. Different models thus include different parameterizations of physical effects as well as different numerical schemes. Because of these differences, no two models yield identical sea-states, a source of confusion and dispute in establishing safety requirements and design criteria for offshore operations. To quote from Ocean Wave Modeling, 'Even for a specialist it is often difficult to distinguish between effects due to the more reliable features of a wave modek which are supported by theory and observations, and the less reliable properties, representing extrapolations of observations and parameterizations'. To progress beyond this labyrinth of specificity, designers and users of wave forecasting models joined forces in a Sea Wave Modeling Project (the SWAMP Group). Models from the U.K., Norway, the Netherlands and Italy (one from each country) and from the U.S., Japan and Germany (two per country) were compared in a series of tests designed to document their performance under simple wind conditions in order to explore the consequences of the various formulations and to suggest means of improving wave modeling in general. Ocean Wave Modeling presents the results of the tests and the conclusions drawn from them. The book is divided into two parts. The first part begins
Stochastic Modeling of Ocean Dynamics. I.E. Timchenko. Translated from Russian by E.T. Premuzic. Harwood Academic Publishers, New York, 1984, viii + 311 pp., US$ 135.00, hardback. It is commendable that Dr Timchenko recognized quite early the need to combine dynamics, data acquisition and statistics of uncertainty in a systematic way as an important part of the maturing s~ience of oceanology. The need for such research, bringing in aspects of control and information theory, is becoming more widely appreciated. Dr Timchenko is to be credited with the foresight to prepare a monograph in this area. Discussion of a number of actual field applications enhances the work. Perhaps because of the importance of these topics, I found the book frustrating. Much as one may sympathize with the author's viewpoint, lengthy philosophical advertisements prove quite repetitive throughout the text. On the other side, important technical discussions can be terse to the point of undefined. More grievous is that the English production of the book is flawed throughout. Simpler errors of translation are only amusing, as the 'derivatization' of 'impartial equations', the 'inertion' of the 'turbulency' or the use of 'optical filter equations'. The greater difficulty is with garbled text in the course of technical development. Attempting tb circumvent text by proceeding from equation to equation, there appear to be mathematical errors, apart from typographic errors which also occur in equations. But it is difficult to say if errors are present in mathematical logic or if there's only ambiguity because some logical operations are recounted in garbled text. Symbols in equations sometimes differ from the symbols used in adjacent text. I don't know to what extent these difficulties occur in the original text or arise in translation and production. A feature of the text is discussion of field applications, particularly from the POLYMODE experiment and from a Bay of Lyons survey. Here, however, it is regrettable that figure labels are sometimes inadequate to identify what is plotted. Text suggests further confusion, as when POLYMODE zonal velocity spectra are described as limited to one minute periods. An item which may be significant but which is not addressed is the fidelity of numerical discretizations of partial differential equations. Results may depend upon aspects of finite differencing but specific methods and quality control are not described. Instead one encounters worrisome remarks
273 such as a calculation dependent upon 'utilization of a non-apparent scheme'. A point to mention is the reference list which may include items not widely known. Overall my view is that a reader seeking to learn about this field will be left frustrated. An advanced researcher thoroughly acquainted with the field may find an interesting challenge to interpret the book, likely uncovering some valuable points. G R E G HOLLOWAY (Sidney, B.C., Canada)
Ocean Wave Modeling. The SWAMP Group. Plenum Press, New York, 1985, vi + 256 pp., US$ 49.50, hardback. Accurate forecasting of wind waves has long been a major concern of the ocean engineer. In recent years, the availability of large computers and the considerable progress made in the understanding of the physics of wind waves have led to the elaboration of numerical models which allow calculation of waves over broad oceanic areas. Such models have been developed in many countries and adapted to local conditions. Each model is based on some compromise between operational requirements, such as speed of calculation, and the need to describe the physics of wave generation, interactions and dissipation as accurately as possible. Different models thus include different parameterizations of physical effects as well as different numerical schemes. Because of these differences, no two models yield identical sea-states, a source of confusion and dispute in establishing safety requirements and design criteria for offshore operations. To quote from Ocean Wave Modeling, 'Even for a specialist it is often difficult to distinguish between effects due to the more reliable features of a wave modek which are supported by theory and observations, and the less reliable properties, representing extrapolations of observations and parameterizations'. To progress beyond this labyrinth of specificity, designers and users of wave forecasting models joined forces in a Sea Wave Modeling Project (the SWAMP Group). Models from the U.K., Norway, the Netherlands and Italy (one from each country) and from the U.S., Japan and Germany (two per country) were compared in a series of tests designed to document their performance under simple wind conditions in order to explore the consequences of the various formulations and to suggest means of improving wave modeling in general. Ocean Wave Modeling presents the results of the tests and the conclusions drawn from them. The book is divided into two parts. The first part begins