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World climatic systems
342
estimating soil thermal conductivity from soil texture, bulk density, and water content data, are scattered throughout the book and will no doubt prove very useful in many applications of soil physics. Ways of dealing with field variability in the deterministic models presented in this book are covered in a separate chapter. A discussion of infiltration and redistribution make up the longest chapter in the book (25 pages) and introduce the complexities of non-linear differential equations. The Newton-Raphson method used to solve these equations is described in considerable detail. I think it unfortunate that the Thomas Algorithm is not discussed in similar detail. Concepts developed in earlier parts of the book are applied in chapters on evaporation, solute movement, and water transport in the soil-plant-atmosphere continuum, and illustrate the strength of the approach adopted by the author in modeling soil physics phenomena. The final chapter emphasises the need for appropriate atmospheric boundary conditions if meaningful model output is to be obtained, and presents several equations for defining these. Although the programs presented in this book are generally short and relatively simple, I, like the author, encourage the reader to " . . . experiment with each model until both the working of the model and the concepts it teaches are familiar". This will be particularly important if they are to be used as submodels in large, general purpose predictive models. Blind application may give results, but the usefulness of the results will ultimately depend on the ability of the user to separate important and subordinate aspects. This will only come from a thorough understanding of the physics involved and the way computer programs are used to describe that physics. Careful study of this excellent book will help achieve that understanding and it is highly recommended to students, teachers, and researchers involved in the soil, plant, and environmental sciences. K E I T H L. B R I S T O W
(Townsville, Australia)
World Climatic Systems. John G. Lockwood, Edward Arnold, London, 1985, x + 292pp., £17.50. The reading to write this review was restarted several times. One of the reasons was that I could not get beyond the first sentence of the actual text, saying "A system may be defined as a structural set of objects and/or attributes, where these objects and attributes consist of components or variables that exhibit discernible relationships with one another and operate together as a complex whole, according to some observed pattern". Oughfff. It could discourage someone to continue reading. And indeed, the introductional sub-chapter which should explain the title of the book is the least successful. The too-short examples used give very inaccurate descriptions of the systems used as illustrations and there is no single reference in these pages. After that the author gets into the routine on the general atmospheric circulation (GAC). Perhaps a bit
343 too much in the routine, as most recent references are to other books on the subjects concerned. Apart from the 1978-paper of Hart, on which the three pages on the geological evolution of the GAC are based, there are only two recent journal paper references, from 1975 and 1981. And I could not locate either of these in the text. Such objections do not apply, at first sight, to the three following chapters on Oceanic, Glacial and Arid Subsystems, the first two of which I looked at rather superficially, but which all appear informative, up-to-date and well documented, given the level at which the book aims: a broad picture of the major climatic processes for second and third year University and Polytechnic students in geography, environmental sciences, and related subjects such as agriculture, and a background text for postgraduate students in the climatological sciences. A special feature of this book, unusual for books of this kind, is the large portion of historical climatology included in the last two abovementioned chapters, which bring features of climatic change, which receive perhaps a bit too much attention in this book, back into their proper perspective. What I sometimes missed in these three chapters is a more thorough attempt to draw some overall conclusions on some issues, which omission is not bad for a "background" course but will be less appreciated by those who require a "broad picture". The chapters on Grassland and Vegetated Subsystems and on Forest Subsystems are a short introduction to the essentials of microclimatology. These chapters may not always contain the best choices, even not from the most widely quoted basic literature, but certainly are in most cases sufficient for the purposes of this book. The large section on (tropical) forests is a very good application of recently developed models, and it is very up-to-date. Part II of this book, Impacts of the Climatic Systems, has two short very introductory chapters on the subjects Climate and Energy and Climate and Food. The former is perhaps better t h a n the latter, although the shortness of the sub-chapter "Climate as an energy source" is disappointing. My assessment of these two chapters may partly be due to my own biases, knowing more about the second subject. However, the purely macroclimatological approach to food production is a rather limiting one and the reasons for such limits do not become very clear. When I reviewed Lockwood's World Climatology (1974), more than ten years ago, I said near the end (I translate from the Dutch): "In this way it became a not very orderly but good review ( . . . ) " . The critical part of this statement does not apply to this book. It is much more orderly than the previous one, due to the use of the mentioned subsystems subdivision. However, because of the failure of the first Chapter, one cannot call this a systems approach. It has been written using a systematical approach, which is something else, but which makes it largely serve the stated educational purposes. c.J. STIGTER (TTMI-Project, Agricultural University of Wageningen, The Netherlands)
estimating soil thermal conductivity from soil texture, bulk density, and water content data, are scattered throughout the book and will no doubt prove very useful in many applications of soil physics. Ways of dealing with field variability in the deterministic models presented in this book are covered in a separate chapter. A discussion of infiltration and redistribution make up the longest chapter in the book (25 pages) and introduce the complexities of non-linear differential equations. The Newton-Raphson method used to solve these equations is described in considerable detail. I think it unfortunate that the Thomas Algorithm is not discussed in similar detail. Concepts developed in earlier parts of the book are applied in chapters on evaporation, solute movement, and water transport in the soil-plant-atmosphere continuum, and illustrate the strength of the approach adopted by the author in modeling soil physics phenomena. The final chapter emphasises the need for appropriate atmospheric boundary conditions if meaningful model output is to be obtained, and presents several equations for defining these. Although the programs presented in this book are generally short and relatively simple, I, like the author, encourage the reader to " . . . experiment with each model until both the working of the model and the concepts it teaches are familiar". This will be particularly important if they are to be used as submodels in large, general purpose predictive models. Blind application may give results, but the usefulness of the results will ultimately depend on the ability of the user to separate important and subordinate aspects. This will only come from a thorough understanding of the physics involved and the way computer programs are used to describe that physics. Careful study of this excellent book will help achieve that understanding and it is highly recommended to students, teachers, and researchers involved in the soil, plant, and environmental sciences. K E I T H L. B R I S T O W
(Townsville, Australia)
World Climatic Systems. John G. Lockwood, Edward Arnold, London, 1985, x + 292pp., £17.50. The reading to write this review was restarted several times. One of the reasons was that I could not get beyond the first sentence of the actual text, saying "A system may be defined as a structural set of objects and/or attributes, where these objects and attributes consist of components or variables that exhibit discernible relationships with one another and operate together as a complex whole, according to some observed pattern". Oughfff. It could discourage someone to continue reading. And indeed, the introductional sub-chapter which should explain the title of the book is the least successful. The too-short examples used give very inaccurate descriptions of the systems used as illustrations and there is no single reference in these pages. After that the author gets into the routine on the general atmospheric circulation (GAC). Perhaps a bit
343 too much in the routine, as most recent references are to other books on the subjects concerned. Apart from the 1978-paper of Hart, on which the three pages on the geological evolution of the GAC are based, there are only two recent journal paper references, from 1975 and 1981. And I could not locate either of these in the text. Such objections do not apply, at first sight, to the three following chapters on Oceanic, Glacial and Arid Subsystems, the first two of which I looked at rather superficially, but which all appear informative, up-to-date and well documented, given the level at which the book aims: a broad picture of the major climatic processes for second and third year University and Polytechnic students in geography, environmental sciences, and related subjects such as agriculture, and a background text for postgraduate students in the climatological sciences. A special feature of this book, unusual for books of this kind, is the large portion of historical climatology included in the last two abovementioned chapters, which bring features of climatic change, which receive perhaps a bit too much attention in this book, back into their proper perspective. What I sometimes missed in these three chapters is a more thorough attempt to draw some overall conclusions on some issues, which omission is not bad for a "background" course but will be less appreciated by those who require a "broad picture". The chapters on Grassland and Vegetated Subsystems and on Forest Subsystems are a short introduction to the essentials of microclimatology. These chapters may not always contain the best choices, even not from the most widely quoted basic literature, but certainly are in most cases sufficient for the purposes of this book. The large section on (tropical) forests is a very good application of recently developed models, and it is very up-to-date. Part II of this book, Impacts of the Climatic Systems, has two short very introductory chapters on the subjects Climate and Energy and Climate and Food. The former is perhaps better t h a n the latter, although the shortness of the sub-chapter "Climate as an energy source" is disappointing. My assessment of these two chapters may partly be due to my own biases, knowing more about the second subject. However, the purely macroclimatological approach to food production is a rather limiting one and the reasons for such limits do not become very clear. When I reviewed Lockwood's World Climatology (1974), more than ten years ago, I said near the end (I translate from the Dutch): "In this way it became a not very orderly but good review ( . . . ) " . The critical part of this statement does not apply to this book. It is much more orderly than the previous one, due to the use of the mentioned subsystems subdivision. However, because of the failure of the first Chapter, one cannot call this a systems approach. It has been written using a systematical approach, which is something else, but which makes it largely serve the stated educational purposes. c.J. STIGTER (TTMI-Project, Agricultural University of Wageningen, The Netherlands)