Divine Wind: The History and Science of Hurricanes

  • Kerry Emanuel
Oxford University Press: 2005. 304 pp. $45, £26.99 0195149416 | ISBN: 0-195-14941-6

The tropical atmosphere has recently been surpassing itself. In late August, Hurricane Katrina, following an encounter with South Florida, devastated parts of the US Gulf coast and led to the inundation of New Orleans. This hurricane has been called the worst natural disaster ever to hit the United States. The total number of fatalities has not yet been tallied, but it is expected to be high, and the number of people displaced, damage to property, and economic loss from the disappearance of businesses and interruption of oil and gas production are staggering. Hurricane Ophelia, which came soon after Katrina, brushed the Carolina coasts, and Hurricane Rita struck Louisiana and Texas. During the previous hurricane season, Florida was struck by a record number of hurricanes.

Divine Wind by Kerry Emanuel is therefore timely. Whereas other books on hurricanes focus on history, such as Erik Larson's Isaac's Storm (Little Brown, 1999), or on science, like Rick Anthes' Tropical Cyclones (American Meteorological Society, 1982), Divine Wind addresses both. Emanuel deftly interweaves an exposition of the science of hurricanes with historical accounts of major tropical cyclones and artists' impressions of the feelings that these tropical tempests instil. He also describes the challenge of predicting and understanding hurricanes. The book does a remarkable job of covering the history, science and terrible beauty of hurricanes, which makes it tempting not only to the storm aficionado and professional scientist, but also to the general public.

Emanuel's inclusion of art has a welcome humanizing effect. A scientific discussion of what happens when a hurricane makes landfall is framed within Richard Strauss's tone poem Death and Transfiguration. Technical figures such as satellite and radar images are intermixed with historical photographs and realistic, abstract and sometimes apocalyptic paintings. There are poems of the regular, not tone, variety, and colourful and easy-to-interpret figures illustrating scientific principles. Instrumentation such as radar, satellites, aircraft, remotely piloted aircraft and scatterometers is also described and explained. Throughout, Emanuel achieves a perfect balance between the scientific and non-scientific aspects of hurricanes.

Tossed and blown: ships take a battering in Engel Hoogerheyden's 1795 painting The Eye of the Hurricane. Credit: KARSTEN BUCHHOLZ/KG HAMBURG

My favourite chapter is a photo essay depicting the inside of a hurricane or typhoon. Hurricanes are dangerous, but they are beautiful too, if observed from the safety of an aircraft inside the eye of the storm or from space. One photograph, taken during a US Air Force reconnaissance flight, shows the eye of a typhoon viewed from below. Others have views looking straight down at the turbulent ocean surface and windblown spray, and there is even one image from the space shuttle. Emanuel compares a view of the eye of a typhoon with a scene from Dante's Inferno.

There are accounts of major historical hurricanes and typhoons. Some of them affected the course of history, such as the typhoons that struck Japan in the thirteenth century (the ‘divine wind’, or kamikaze, that saved Japan from Kublai Khan), and a hurricane in the sixteenth century that interfered with an attempt by the French to settle Florida. The ‘great hurricane’ of 1780 in the Caribbean was one of the deadliest hurricanes ever to strike in that part of the world. The book also covers the 1900 Galveston hurricane, the New England hurricane of 1938, Hurricane Camille in 1969, Cyclone Tracy in Australia in Christmas 1974 and Hurricane Andrew in 1992. The effects of Katrina are likely to be as long lasting, politically, socially and economically, as those of its predecessors. Other books have dealt with the historical accounts in more depth, but the overall effect of those in Divine Wind is unique.

Emanuel notes a similarity between The Tempest and an account of a hurricane in 1609 given by William Strachey, an acquaintance of William Shakespeare. Many scholars say this rules out Edward De Vere as a possible author of The Tempest, because he died before Strachey told his tale. Strachey's account itself is poetic:

For four and twenty hours the storm in a restless tumult, had blown so exceedingly, as we could not apprehend in our imagination any possibility of greater violence, yet did we still find it, not more terrible, but more constant, fury added to fury, and one storm urging a second more outrageous than the former...The Sea swelled above the clouds, and gave battle unto heaven.

A pioneering hurricane researcher, Emanuel presents the science at a level that is not too technical for non-specialists, yet is sufficient to describe the basic physics with few equations. Hurricane formation, energetics and ocean interaction are all clearly explained. The fundamentals of numerical weather prediction using computers, including chaos theory and its relevance to forecasting, are also well treated. The only minor criticism I have is that each of the forces that control the behaviour of hurricanes is treated separately. It would have been nice if the effects of all the forces had been summarized, particularly in the section on numerical weather prediction, where only the sum of all the forces is noted.

Emanuel has recently been in the public eye as a result of his recent letter in Nature (436, 686–688, 2005), in which he suggested that any further warming of the troposphere might increase the destructive potential of tropical cyclones. His book ends with some further provocative thoughts on hurricanes and climate.