The Elephant's Trunk: Meteorology and the Origins of Climatology

by Michael Tobis     Department: Earth

I really am convinced that climatology is the most important science around, and not because of the climate change problem. Yes, the climate change problem is important, but science is important too.

Climatology is intellectually important because it brings so many existing branches of knowledge together into a testable formal framework or "model". Its work lies at the frontier of complexity, a frontier with purely formalizable knowledge behind it (physics, chemistry) and heuristics ahead of it (physiology, ecology).

In other words it is exactly at the limits of hard science. It's an exciting place to be, if (and only if) you are armed with a good grasp of how to manage complexity. Perhaps, like physics was in the past, it is the model of scientific investigation for the future.

Telling the story of this amazing science is what I'm trying to do here. I'd like climate science to be appreciated for itself, not just for its role in a controversy. Because of its complexity, it's hard to know where to start, which of the many threads to pick up first. Different climate workers see different aspects of the beast, as in the parable of the blind men and the elephant.

Image by Schuyler Shepherd in the Ngorongoro crater, Tanzania licensed under Creative Commons Attribution 2.5 License;  details here.

Still, I think the study of the atmosphere is clearly the aspect that best gets the story of climate started. It's the trunk of the elephant, the most notable feature, aside perhaps, from the hugeness of the beast.

You could say that the history of meteorology is as long as the history of humanity. Early peoples did not distinguish between astronomy and meteorology. It was all the study of the sky.  That's why when little chunks of deep space fall on our cornfields we call them "meteorites". The "meteor" root of both words is the same, originally meaning "stuff that falls out of the sky". Qualitative daily records of weather can be found far back in the past,  for example those of Willam Merle at Oxford from 1337 through 1344. Of course, weather forecasting lore ("red sky at night...") is ancient.

Things changed substantially in the 1600s, when thermometers and barometers were perfected. Formal measurements of rainfall and wind velocity also began about that time. This was in the early days of science, when the connections between mathematics and nature were becoming apparent, so of course in the light of the newly rich data, a search for laws of the atmosphere began in earnest.

Early successes came from the widely traveled British Navy. Sir Edmund Halley, famed for the discovery of the comet that bears his name, created a map of the entire tropics showing the prevailing winds. This was a new kind of observation, requiring a new kind of explanation. It became clear from these sorts of pictures that the weather could be treated as a local manifestation of a very large scale flow of air, but it wasn't immediately obvious how to analyze that flow.

A contemporary of Halley, who had the double misfortune of having a name similar to Halley's and an illustrious older brother James, was George Hadley. Though not especially celebrated in his time, he was a Fellow of the Royal Society. Today he is regarded as arguably the first scientific meteorologist, with a major feature of the atmosphere (the Hadley Circulation) and a major research institution (the Hadley Centre in Exeter, England) named after him. Hadley's main contribution was a connection of a physics principle, conservation of angular momentum, to an atmospheric feature, predominantly westward ("easterly") winds in the tropics and predominantly eastward ("westerly") winds in the high latitudes. Important in itself, this also constitutes the first application of quantitative thinking to the atmosphere, and thus the birth of meteorology as a branch of physics.

Unfortunately, this promising beginning did not lead to the sorts of intellectual momentum that other fields achieved in the 1700s and 1800s. A great deal of data was amassed, and the sky remained interesting of course.

Some progress was made in other fields that feed into our present science, but the science of atmospheric motion eluded the sorts of generalization that other sciences triumphantly achieved, the finest example being James Clerk Maxwell's codification of electromagnetics in the 1840s.

I think Maxwell's astonishing (and perhaps underappreciated) achievement sets the bar too high for the rest of human knowledge and leads to some misunderstanding of how we can go about understanding other aspects of nature. Maybe that's a topic for another essay. Meteorology was one of the disciplines that sought for a comparable synthesis, with limited progress until the turn of the twentieth century.

The development of the telegraph did enable a new approach to weather prediction, as it became possible to assemble observations from remote sites and draw a weather map. Such a weather map was called "synoptic" at the time, meaning "seeing at the same time", since prior to the telegraph seeing simultaneous information from many sites was by contrast impossible. There is nothing "optical" involved so it's something of a misnomer, but the word "synoptics" persists to this day for regional weather prediction.

This allowed a new form of weather prediction lore to emerge. Experts could become familiar with the structure of the synoptic maps and make educated guesses as to how they would evolve. This skill became a profession, with newspapers and shipping interests, and eventually airlines, hiring synopticians.

By the end of the nineteenth century, three very distinct activities and subcultures split the attentions of meteorologists. Those collecting statistics and seeking patterns among them without much reference to physics were called "climatologists". Those attempting to make economically useful predictions were "synopticians" or "operational meteorologists" and those attempting to understand what they were seeing were "theoretical meteorologists" or "physical meteorologists".

Today's computational climatology emerges from all three threads and others. Next in this series, we'll look at the aspirations and controversies of the theoretical school, how they broke the logjam, what they achieved in the early twentieth century, and what eluded them.

The next chapter of our saga takes place mostly in Norway, as a good saga ought to do.

(Many of the facts in this essay are from the book "Calculating the Weather" by Frederik Nebeker, but you can blame me for most of the ideas.)

Tags: climate, history

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