METEOSAT-2

Courtesy the European Space Agency

The first visual image received from the geostationary satellite METEOSAT-2, the second in theseries ofexperimental satellitesput into operation by the European Space Agency. The picturewas taken on 28 July 1981

BOOK REVIEW

RAINBOWS, HALOS AND GLORIES. By Robert Greenler. Cambridge UniversityPress, 1980. 195 pp. Price £15·00On looking back through past issues of Weather it is obvious that there is a keen

interest amongst readers in optical phenomena in the atmosphere. Within the last yearor so a photograph and explanation of a striking anomalous rainbow led to severalletters and alternative explanations. Other articles and correspondence have related tohalo phenomena caused by the scattering of sunlight through ice crystals. The article

371

by Robert Greenler and others in last December's issue brought the subject up to date,by showing how complex ice crystal halo displays may be understood with the help of acomputer simulation technique. This new book by Greenler should therefore havewide appeal, as it covers the whole range of such phenomena in a highly readable andinformative style.

The book contains chapters describing rainbows, ice crystal halos and othereffects, which together may lead to complex displays covering the whole sky. There arealso descriptions of light scattering and refraction by the atmosphere and diffractioneffects such as coronae and glories. For all these phenomena explanations are given innon-technical language so as not to restrict the readership; those seeking themathematical details are referred elsewhere by a carefully chosen list of specialistbooks and technical papers. The author is particularly interested in the diverse rangeof effects produced by ice crystals and this is reflected in the amount of space devotedto them. Some of the detail may seem out of place here, but it is necessary in order tounderstand the dazzling displays seen in polar regions. A very useful table illustratesthe ray paths through the crystals which are responsible for each component of suchdisplays and this helps the casual reader to circumvent the more esoteric parts of thesechapters.

The most attractive aspect of the book is undoubtedly the large number of excel­lent colour photographs. These are bound together on high quality paper in the centreof the book, which is presumably necessary for reasons of economy, although thisinevitably increases the amount of page turning required to follow the text. This can beirritating of course, especially when many photographs seem rather unnecessarily tohave been set on their sides. Many illustrate phenomena which are rarely seen, yet allare of high quality and include several taken by the author. Some are extraordinarilydetailed records of ice crystal displays and apart from many photographs of rainbowsand glories there are also examples of some bizarre mirage effects. The text itself isalso liberally provided with diagrams and monochrome photographs. Each chapterincludes at least one 'puzzle-picture', which is left for the reader to explain, althoughthankfully all are discussed in detail in an appendix.

The author's enthusiasm for his subject results in a free-flowing narrative stylewhich communicates a sense of wonder and delight in the enormous range of opticaleffects which may be seen. Altogether this is an excellent book which can be recom­mended as a spur to a greater awareness and understanding of these beautifulphenomena.

A. SUNGO

LEITERS TO THE EDITORCorrespondents are requested to observe the following rules when submitting letters

for publication: the material should be typed or clearly written on one side ofthe paperonly: it should carry ample margins at top and bottom as well as each side of the text:typed matter should be double line-spaced.

The winters of 1962163 and 1978179

I found the notes from Mr R Heape (Weather, 36, pp. 31, 344) concerningobservations made at Stapenhill in Burton on Trent extremely interesting, and theycertainly helped to put the comparison between these two winters in better perspec­tive.

While appreciating all along that the severity of the 1962/63 winter was greaterthan that of 1978/79, some of the individual events of the latter were of greatersignificance. May I refer to my letter (Weather, 34(5), p. 205) where some of the moreextreme temperature details were given. Since that time, my researches into the verylow temperatures of 3 January 1979 (-16.2°C minimum and -1l.5°C maximum)seem to point to only three other similar instances since 1879 when temperatures are

372