Monday, September 17, 2007

History of Aerosol Science


The first time my interest in aerosol science picked up was when I learnt about nuclear winter -- a phenomena which refers to possible climatic impact of all-out nuclear war. What really fascinated me was the idea that if one wants to control climate or weather in predictive manner, aerosols are going to be the best tool; for a reason that they have relatively short life-time giving control over their introduction and removal in the atmosphere. Well! this is not the subject of today's post. Thinking of my own interests in this field led me to think about history of aerosol science. Couple of years before I read Spencer Weart's "The Discovery of Global Warming". I am fascinated by its content and writing style. Experience was not less than reading suspense thriller. Later on, I come across a comment that book is weighted toward contributions of American scientists than European scientists. I do not know the truth as my knowledge in the history of climate science is limited. But if asked Weart's book is my first recommendation.

The climate scientist J. Murray Mitchell, Jr. took up the question, with the help of improved data on how minuscule particles (aerosols) moved through the upper atmosphere. Studies of fallout from nuclear bomb tests had shown that fine dust injected into the stratosphere would linger for a few years, but would not cross from one hemisphere to the other. With that in mind, Mitchell pored over global temperature statistics and put them alongside the record of volcanic eruptions. In 1961, he announced that large eruptions caused a significant part of the irregular variations in average annual temperature in a given hemisphere. On the other hand, average temperatures had fallen since 1940, a period in which the world had seen few major eruptions. Mitchell concluded that the recent cooling was an "enigma." He thought it might signal a new phase of a decades-long "rhythm," the sort of cycle that generations of climatologists had tried to winkle out of their data
While thinking of Weart's book, I started searching what resources are available on Internet about history of aerosol science and to my delight I found that Weart has created web-pages to supplement his book. On his web-page you can read history of aerosol science and global warming with full references, illustrations and pictures of scientists. A link is available to download whole web-site in zip file so one can burn his/her own CD, or one can download PDF file and print it and of cause one can read it online. Following is the link to table of content.

Climate Change: Discovery of Global Warming
http://aip.org/history/climate/

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