Clouds populate our skies continuously, but we tend to pay little attention to them and often we note their presence only when they are very colorful at dawn or dusk or when they are associated with intense or even destructive meteorological phenomena. However, they are always up there above our heads even when the sky is deep blue and cloudless. Don’t worry, a cloud is forming somewhere and it will soon be visible!
Observing clouds may seem a pointless exercise, not very useful, right? It is not true and Vincenzo Levizzani of the Institute of Atmospheric Sciences and Climate (Isac) of Cnr in Bologna says that he works with his “head in the clouds” every day. His life was spent observing and studying clouds in the lab, on an aircraft and using meteorological radars and satellites. Moreover, he teaches cloud physics at the University of Bologna.
As a further effort he just published the book “Il libro delle nuvole. Manuale pratico e teorico per leggere il cielo” (Il Saggiatore, 240 pagine, https://www.ilsaggiatore.com/libro/il-libro-delle-nuvole/). The book scope is to tell the reader what clouds are all about, how they form, what are their constituents, why they have different forms and colors. In a nutshell: why we talk about clouds instead of a single cloud.
The trip starts with a brief history of the relationship between man and the clouds both as physical objects and also as poetic and artistic concepts. We then go through the classification of clouds that allows us to distinguish between cirrus, cumulus, cumulonimbus and much more. The cloudy path continues by penetrating clouds while they are forming to understand how mountains, lakes and oceans largely determine cloud structure. When we are inside a cloud it is impossible not to notice that we are surrounded by its primary constituents, the hydrometeors, i.e. droplets, crystals, snowflakes, graupels and hailstones. The author explains in detail their formation entering a microscopic world that is behind the final aspect of the cloud and its evolution. Moving from hydrometeors the book brings us inside precipitating clouds to investigate how drops and crystals grow until they are large and heavy enough to fall on our heads as rain and snow. We are transported inside clouds with supersonic jets instrumented with very sophisticated equipment to study hydrometeors in their own environment; radars and satellites observe the inner structure of clouds to give reason of their continuous changes at all scales. Finally, the book examines applications of cloud science in meteorology and climate to understand why studying clouds is vital to correctly forecast weather and draw future climate scenarios.
The trip is intriguing and rigorous at the same time. We visit the skies meeting great scientists who dedicated their lives to a better understanding of cloudy skies and who applied physics and chemistry to describe cloud structure from the small cumulus to the giant tropical hurricane. Levizzani tells us that we can build our own personal cloud “library” out of the clouds above our heads and find out that each one of them is truly unique. At the same time, knowing clouds is not only for scientists, we can all study them: you only have to like them! Most probably, after reading this book, you will never look at the sky again without asking yourself several questions and wait for the next cloud…
To know more:
Levizzani, V., 2021: Il libro delle nuvole. Manuale pratico e teorico per leggere il cielo. Il Saggiatore, Milano, ISBN 9788842826828, 240 pp.
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