{'fraction_non_alphanumeric': 0.022844827586206897, 'fraction_numerical': 0.006681034482758621, 'mean_word_length': 4.859848484848484, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
High Latitude Climate and Remote Sensing K.Ya. Kondratyev, O.M. Johannessen and V.V. Melentyev John Wiley & Sons, Chichester (1996). 200 pages + viii + 8 colour plates. £50. ISBN 0 471 96093 4

Readers of this journal will undoubtedly be aware of the significant role played by high-latitude regions in the global climate system, for example through the albedo feedback and thermohaline convection, and of the sensitivity of both polar regions, particularly the Arctic, to climate impacts. The interactions between the major components (land, ocean, ice, atmosphere, biota) have begun to receive detailed scrutiny over the last ten years or so, but our understanding of them is still somewhat limited. This lack of detail is strikingly revealed by the inability of global climate models to account for such climatological data as are available for the polar regions. It is clear that remote sensing, especially from space and especially at microwave frequencies, will increasingly contribute to the ‘climate observing system’ that is so urgently required. Space borne observations can collect spatial data on a regional scale in a time scale that is short compared to that of what are currently believed to be the climatologically important processes; and microwave observations have the great advantage that, unlike optical observations, they can be made throughout the year. These remarks serve to place this book in some sort of context. Having said that, however, I find it rather difficult to characterize it accurately. The first third, divided into two chapters, mostly provides a review of the main issues in highlatitude climate studies. Though comprehensive and stimulating, both of these chapters seem somewhat lacking in perspective. Perhaps this is a consequence of the limited state of knowledge regarding the interactions between the main components of the polar climate systems; it is certainly rather frustrating. The remainder of the book treats the application of remote sensing to high-latitude regions, with a strong bias towards passive microwave techniques applied to polar oceans. Chapter 3 presents a table of spatial and temporal requirements for remote sensing of ice and snow (in fact mainly of sea ice). This is a useful summary, though its value would have been greatly increased if some attempt had been made to relate the requirements to the performance of existing and planned instruments. The second part of this chapter is a short (three page) essay on the use of optical and infrared satellite remote sensing. In such a small space it is hardly possible to do justice to the subject, and one can find fuller treatments of most of this topic elsewhere. Chapter 4 is mainly a review of the microwave dielectric properties of water, ice and snow. Chapter 5, which I found one of the most interesting and potentially useful parts of the book, presents theory and results of numerical modelling of the microwave emissivity of water, ice, snow and (to a very limited extent) frozen soil. Chapter 6 reviews the use of passive microwave data and, in less detail, imaging radar, in the study of polar environments. Most of this material is readily available elsewhere, and its organization here is not particularly clear. Chapter 7 describes various Russian experimental investigations carried out between 1973-85, into the use of passive microwave radiometry and imaging radar for determining sea ice concentration, type and thickness. The results are not really presented in sufficient detail to enable the reader to assess the claims made for them. It may be true that the technology and innovation displayed here represented significant advances at the time; if so, it is another example of the unhappy effect of the limited possibilities for communication between Russian and western scientists at that time. However, the material must now be mainly of historical interest since the field of microwave remote sensing of sea ice has developed rapidly in the last ten years. In summary, I have to say that I found this a rather disappointing book. The coverage is more limited than the title suggests, and the linkage between the discussion of highlatitude climate and of remote sensing techniques is less well developed than I would have liked (the use of the word ‘and’ in the title is quite proper). The ‘Anglicization’ of the text is also less than perfect in places. Nevertheless, I am sure the book will be read with interest by anyone working in the fields of high-latitude climate researchor microwave remote sensing of sea ice, not least for the list of four or five hundred references. W. GARETH REES