Guest Author - Anita Grace Simpson
The Book of Clouds by John A. Day is one of the best cloud reference books I have ever seen. Its large format does make it less appropriate for cloud watching on hikes and camping trips, but for home or car based cloud identification, this book is ideal. Its stunning photographs give several examples for each type of cloud that Day lists. With such gorgeous picture quality, it could even be a coffee table book!
However, The Book of Clouds is more than just a collection of cloud photos. The book begins with a discussion of the water cycle and how clouds form. Day mentions the roles of water and air, as well as factors that influence cloud formations. These include particles in the atmosphere, temperature, hot air rising, physical barriers, and surface fronts. He compares clouds to galaxies in order to explain the deceptive structure of a cloud.
Day divides clouds and other optical atmospheric phenomena into six categories: cumulus family, stratus family, cumulus / stratus mixtures, precipitating clouds, optical effects, and unusual clouds. The bulk of the book consists of photos and supporting information for subtypes in each category. He finishes with a chapter on the man who first named cloud, Luke Howard, and another on forecasting weather using clouds. A glossary and index support the text.
The book gives extra information for each cloud subtype in the first four categories. This includes base altitude, top altitude, stability of the surrounding airmass, buoyancy, moisture content, temperature, and precipitation type (if any). For example, cirrocumulus clouds are mixtures of cumulus and stratus that have a base altitude of 20,000-23,000 feet and top altitude of 23,000-27,000 feet (approximately five miles). They indicate air that is slightly unstable, with positive buoyancy (tendency to rise) and a low moisture content. The temperature is usually at or below freezing, so these clouds are primarily composed of ice crystals. Typically they do not produce precipitation.
According to Day, Luke Howard, who developed the cloud-naming system, used Latin words such as “cumulus” (heap), “stratus” (layer), and “nimbus” (rain), following the example of the famous taxonomist of living things, Linnaeus. It was Linnaeus who devised the well-known scheme of naming life forms by their genus and species (also based on Latin in most cases). Howard took this idea and applied it to clouds, noting their similarities and differences in shape, as well as in the weather phenomena associated with them.
Finally, Day gives tips on using cloud formations as predictors of upcoming weather. He includes a list of 10 reliable cloud indicators, such as “cumulus congestus clouds, thickening with towers rising, mean showers in the next few hours,” and “darkening and lowering cumulonimbus with falling barometer indicates severe storms approaching.”
I highly recommend this book to anyone who is interested in clouds, from the casual cloud watcher to the serious amateur meteorologist.
Buy The Book of Clouds at Amazon