Taxonomy is the art of classification; it is the discipline of compiling in minute and esoteric detail what Keats described as "the dull catalogue of common things". And meteorologists are experts at it.
To ensure global uniformity in weather reports, every aspect of the weather must be defined, verified, validated and clarified down to the very smallest detail. Cloud taxonomy provides a case in point.
Now if the 19th century art critic, John Ruskin, were to be believed, there would be no possibility of classifying clouds. "Nature" in his view, "never lets one of the members of even her most disciplined groups of clouds be like another; but though each is adapted for the same function, and in its great features resembles all the others, not one out of the millions with which the sky is chequered is without a separate beauty and character".
But greater minds than Ruskin's, or minds, at any rate, whose focus was not quite the same, brought order into this aesthetic chaos. It was noted that while clouds indeed differed from each other in an infinite variety of detail, they assumed, nonetheless, a limited number of common shapes.
This was confirmed in 1887 by Ruskin's contemporary, the English meteorologist Ralph Abercromby, who travelled around the world apparently with no other objective in mind except to make sure that clouds looked everywhere the same.
And yet they differ. The first serious attempt to classify clouds was that by the French naturalist Jean Lamarck in 1802, who proposed five main divisions comprising hazy, massed, dappled, broom-like and grouped. This rather gauche nomenclature was superseded shortly afterwards by a Latin taxonomy suggested by the English meteorologist Luke Howard, and this proved to be more popular and more enduring.
Howard assigned to each cloud type a Latin name according to its general appearance. Cirrus meaning curl, was used to describe wispy, fibrous strands; cumulus or mass was ascribed to flat-based heapclouds extending upwards through the atmosphere; and stratus meaning spread out, was the label attached to low, horizontal sheets.
These three primary categories, in various combinations, became the basis for the ten main cloud families: cirrus, cirrocumulus, and cirrostratus; altocumulus, altostratus, and nimbostratus; and stratus, stra- tocumulus, cumulus and cumuonimbus.
Even today, the aspiring weatherperson must not only be able to distinguish easily these ten different types of cloud, but must be able to subdivide them further using words from a lengthy litany of Latin adjectives, in much the same way as botanists classify their plants.
And meteorologists further distinguish cloud-types by their height, which with quite disarming clarity they describe as simply low, medium or high.