Meteorology

It was not until after the elucidation of the laws of physics, and more particularly in the latter half of the 20th century, the development of the computer (allowing for the automated solution of a great many modelling equations) that significant breakthroughs in weather forecasting were achieved.

The word meteorology is from the Ancient Greek μετέωρος metéōros (meteor) and -λογία -logia (-(o)logy), meaning "the study of things high in the air".

[1] The ability to predict rains and floods based on annual cycles was evidently used by humans at least from the time of agricultural settlement if not earlier.

[5] According to Seneca, he gave the explanation that the cause of the Nile's annual floods was due to northerly winds hindering its descent by the sea.

[16] His system was based on dividing the year by the setting and the rising of the Pleiad, halves into solstices and equinoxes, and the continuity of the weather for those periods.

[17] Applying the divisions and a principle of balance in the yearly weather, he came up with forecasts like that if a lot of rain falls in the winter, the spring is usually dry.

In his Opus majus, he followed Aristotle's theory on the atmosphere being composed of water, air, and fire, supplemented by optics and geometric proofs.

[36] By the middle of the sixteenth century, meteorology had developed along two lines: theoretical science based on Meteorologica, and astrological weather forecasting.

[40] In the 18th century, the invention of the thermometer and barometer allowed for more accurate measurements of temperature and pressure, leading to a better understanding of atmospheric processes.

[41] In the 19th century, advances in technology such as the telegraph and photography led to the creation of weather observing networks and the ability to track storms.

In current time, with the advancement in weather forecasting and satellite technology, meteorology has become an integral part of everyday life, and is used for many purposes such as aviation, agriculture, and disaster management.

In 1824, Sadi Carnot analyzed the efficiency of steam engines using caloric theory; he developed the notion of a reversible process and, in postulating that no such thing exists in nature, laid the foundation for the second law of thermodynamics.

[57] In 1686, Edmund Halley presented a systematic study of the trade winds and monsoons and identified solar heating as the cause of atmospheric motions.

[59] In 1743, when Benjamin Franklin was prevented from seeing a lunar eclipse by a hurricane, he decided that cyclones move in a contrary manner to the winds at their periphery.

[61] In 1856, William Ferrel proposed the existence of a circulation cell in the mid-latitudes, and the air within deflected by the Coriolis force resulting in the prevailing westerly winds.

[64] The group included Carl-Gustaf Rossby (who was the first to explain the large scale atmospheric flow in terms of fluid dynamics), Tor Bergeron (who first determined how rain forms) and Jacob Bjerknes.

[65] In 1654, Ferdinando II de Medici established the first weather observing network, that consisted of meteorological stations in Florence, Cutigliano, Vallombrosa, Bologna, Parma, Milan, Innsbruck, Osnabrück, Paris and Warsaw.

[67] The arrival of the electrical telegraph in 1837 afforded, for the first time, a practical method for quickly gathering surface weather observations from a wide area.

[72] In 1854, the United Kingdom government appointed Robert FitzRoy to the new office of Meteorological Statist to the Board of Trade with the task of gathering weather observations at sea.

The following year a system was introduced of hoisting storm warning cones at principal ports when a gale was expected.

In 1922, Lewis Fry Richardson published "Weather Prediction By Numerical Process,"[81] after finding notes and derivations he worked on as an ambulance driver in World War I.

He described how small terms in the prognostic fluid dynamics equations that govern atmospheric flow could be neglected, and a numerical calculation scheme that could be devised to allow predictions.

[82] The first weather forecasts derived this way used barotropic (single-vertical-level) models, and could successfully predict the large-scale movement of midlatitude Rossby waves, that is, the pattern of atmospheric lows and highs.

[84] In the 1960s, the chaotic nature of the atmosphere was first observed and mathematically described by Edward Lorenz, founding the field of chaos theory.

[88] Meteorologists work in government agencies, private consulting and research services, industrial enterprises, utilities, radio and television stations, and in education.

The terms meso-alpha, meso-beta, and meso-gamma to classify the horizontal scales of atmospheric processes were introduced to the field of mesoscale meteorology by Isidoro Orlanski.

The events typically of interest are thunderstorms, squall lines, fronts, precipitation bands in tropical and extratropical cyclones, and topographically generated weather systems such as mountain waves and sea and land breezes.

At the synoptic scale, the Coriolis acceleration acting on moving air masses (outside of the tropics) plays a dominant role in predictions.

The phenomena typically described by synoptic meteorology include events such as extratropical cyclones, baroclinic troughs and ridges, frontal zones, and to some extent jet streams.

It takes but 1/2 inch of ice to reduce the lifting power of some aircraft by 50 percent and increases the frictional drag by an equal percentage.

Twilight at Baker Beach
A hemispherical cup anemometer
General circulation of the Earth's atmosphere: The westerlies and trade winds are part of the Earth's atmospheric circulation.
Cloud classification by altitude of occurrence
This "Hyetographic or Rain Map of the World" was first published 1848 by Alexander Keith Johnston .
This "Hyetographic or Rain Map of Europe" was also published in 1848 as part of "The Physical Atlas".
A meteorologist at the console of the IBM 7090 in the Joint Numerical Weather Prediction Unit, c. 1965
Satellite image of Hurricane Hugo with a polar low visible at the top of the image
NOAA : Synoptic scale weather analysis
Annual mean sea surface temperatures
Forecast of surface pressures five days into the future for the north Pacific, North America, and north Atlantic Ocean