Meteorology is the scientific study of the Earth's atmosphere and short-term atmospheric phenomena (i.e., weather), with a focus on weather forecasting. It has applications in the military, aviation, energy production, transport, agriculture, construction, weather warnings, and disaster management.
Along with climatology, atmospheric physics, atmospheric chemistry, and aeronomy, meteorology forms the broader field of the atmospheric sciences. The interactions between Earth's atmosphere and its oceans (notably El Niño and La Niña) are studied in the interdisciplinary field of hydrometeorology. Other interdisciplinary areas include biometeorology, space weather, and planetary meteorology. Marine weather forecasting relates meteorology to maritime and coastal safety, based on atmospheric interactions with large bodies of water.
Meteorologists study meteorological phenomena driven by solar radiation, Earth's rotation, ocean currents, and other factors. These include everyday weather like clouds, precipitation, and wind patterns, as well as severe weather events such as tropical cyclones and severe winter storms. Such phenomena are quantified using variables like temperature, pressure, and humidity, which are then used to forecast weather at local (microscale), regional (mesoscale and synoptic scale), and global scales. Meteorologists collect data using basic instruments like thermometers, barometers, and weather vanes (for surface-level measurements), alongside advanced tools like weather satellites, balloons, reconnaissance aircraft, buoys, and radars. The World Meteorological Organization (WMO) ensures international standardization of meteorological research.
The study of meteorology dates back millennia. Ancient civilizations tried to predict weather through folklore, astrology, and religious rituals. Aristotle's treatise Meteorology sums up early observations of the field, which advanced little during early medieval times but experienced a resurgence during the Renaissance, when Alhazen and René Descartes challenged Aristotelian theories and emphasized scientific methods. In the 18th century, accurate measurement tools (e.g., barometer and thermometer) were developed, and the first meteorological society was founded. In the 19th century, telegraph-based weather observation networks were formed across broad regions. In the 20th century, numerical weather prediction (NWP), coupled with advanced satellite and radar technology, introduced sophisticated forecasting models. Later, computers revolutionized forecasting by processing vast datasets in real time and automatically solving modeling equations. 21st-century meteorology is highly accurate and driven by big data and supercomputing. It is adopting innovations like machine learning, ensemble forecasting, and high-resolution global climate modeling. Climate change–induced extreme weather poses new challenges for forecasting and research, while inherent uncertainty remains because of the atmosphere's chaotic nature (see butterfly effect).
Etymology The word meteorology is from the Ancient Greek μετέωρος metéōros (meteor) and -λογία -logia (-(o)logy).
Aristotle's ancient book Meteorologica covers anything suspended in or falling from the sky, which included both shooting stars and weather phenomena. The word's first appearance in English was in 1563, in William Fulke's book Goodly Gallerye Causes of Meteors. Fulke uses the term "meteors" to include shooting stars, rain, snow, clouds, and even earthquakes. In modern usage, meteor typically refers to a shooting star, which is studied in astronomy rather than meteorology. However, meteor is still used in a meteorological context meaning any phenomenon "observed in the atmosphere or on the surface of the Earth".
History
Ancient meteorology up to the time of Aristotle
Early attempts at predicting weather were often related to prophecy and divining, and were sometimes based on astrological ideas. Ancient religions believed meteorological phenomena to be under the control of the gods. 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. Early approaches to predicting weather were based on astrology and were practiced by priests. The Egyptians had rain-making rituals as early as around 3500 BC.
Ancient Indian Upanishads contain mentions of clouds and seasons. The Samaveda mentions sacrifices to be performed when certain phenomena were noticed. Varāhamihira's classical work Brihatsamhita, written about 500 AD, provides evidence of weather observation.
Cuneiform inscriptions on Babylonian tablets included associations between thunder and rain. The Chaldeans differentiated the 22° and 46° halos.
The ancient Greeks were the first to make theories about the weather. Many natural philosophers studied the weather. However, as meteorological instruments did not exist, the inquiry was largely qualitative, and could only be judged by more general theoretical speculations. Herodotus states that Thales predicted the solar eclipse of 585 BC. He studied Babylonian equinox tables. According to Seneca, he explained that the cause of the Nile's annual floods was due to northerly winds hindering its descent by the sea. Anaximander and Anaximenes thought that thunder and lightning was caused by air smashing against the cloud, thus kindling the flame. Early meteorological theories generally considered that there was a fire-like substance in the atmosphere. Anaximander defined wind as a flowing of air, but this was not generally accepted for centuries. A theory to explain summer hail was first proposed by Anaxagoras. He observed that air temperature decreased with increasing height and that clouds contain moisture. He also noted that heat caused objects to rise, and therefore the heat on a summer day would drive clouds to an altitude where the moisture would freeze. Empedocles theorized on the change of the seasons. He believed that fire and water opposed each other in the atmosphere, and when fire gained the upper hand, the result was summer, and when water did, it was winter. Democritus also wrote about the flooding of the Nile. He said that snow in northern parts of the world melted during the summer solstice. This would cause vapors to form clouds, which would cause storms when driven to the Nile by northerly winds, thus filling the lakes and the Nile. Hippocrates inquired into the effect of weather on health. Eudoxus claimed that bad weather followed four-year periods, according to Pliny.
Aristotelian meteorology These early observations would form the basis for Aristotle's Meteorology, written in 350 BC. Aristotle is considered the founder of meteorology. One of the most impressive achievements described in the Meteorology is the description of what is now known as the hydrologic cycle. His work would remain an authority on meteorology for nearly 2,000 years.
The treatise On the Universe (composed before 250 BC or between 350 and 200 BC) noted:
After Aristotle, progress in meteorology stalled for a long time. Theophrastus compiled a book on weather forecasting, called the Book of Signs, as well as On Winds. He gave hundreds of signs for weather phenomena for a period up to a year. 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. He also divided months into the new moon, fourth day, eighth day and full moon, in likelihood of a change in the weather occurring. The day was divided into sunrise, mid-morning, noon, mid-afternoon and sunset, with corresponding divisions of the night, with change being likely at one of these divisions. 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. Rules based on actions of animals are also present in his work, like that if a dog rolls on the ground, it is a sign of a storm. Shooting stars and the Moon were also considered significant. However, he made no attempt to explain these phenomena, referring only to the Aristotelian method. The work of Theophrastus remained a dominant influence in weather forecasting for nearly 2,000 years.
Meteorology after Aristotle Meteorology continued to be studied and developed over the centuries, but it was not until the Renaissance in the 14th to 17th centuries that significant advancements were made in the field. Scientists such as Galileo and Descartes introduced new methods and ideas, leading to the scientific revolution in meteorology.
Speculation on the cause of the flooding of the Nile ended when Eratosthenes, according to Proclus, stated that it was known that man had gone to the sources of the Nile and observed the rains, although interest in its implications continued.
During the era of Roman Greece and Europe, scientific interest in meteorology waned. In the 1st century BC, most natural philosophers claimed that the clouds and winds extended up to 111 miles, but Posidonius thought that they reached up to five miles, after which the air is clear, liquid and luminous. He closely followed Aristotle's theories. By the end of the second century BC, the center of science shifted from Athens to Alexandria, home to the ancient Library of Alexandria. In the 2nd century AD, Ptolemy's Almagest dealt with meteorology, because it was considered a subset of astronomy. He gave several astrological weather predictions. He constructed a map of the world divided into climatic zones by their illumination, in which the length of the Summer solstice increased by half an hour per zone between the equator and the Arctic. Ptolemy wrote on the atmospheric refraction of light in the context of astronomical observations.Smith AM, 1996. "Ptolemy's Theory of Visual Perception: An English Translation of the Optics", pp. 46. Transactions of the American Philosophical Society vol. 86, part 2.
In 25 AD, Pomponius Mela, a Roman geographer, formalized the climatic zone system. In 63–64 AD, Seneca wrote Naturales quaestiones. It was a compilation and synthesis of ancient Greek theories. However, theology was of foremost importance to Seneca, and he believed that phenomena such as lightning were tied to fate. The second book (chapter) of Pliny the Elder's Natural History covers meteorology. He states that more than twenty ancient Greek authors studied meteorology. He did not make any personal contributions, and the value of his work is in preserving earlier speculation, much like Seneca's work.
From 400 to 1100, scientific learning in Europe was preserved by the clergy. Isidore of Seville devoted a considerable attention to meteorology in Etymologiae, De ordine creaturum and De natura rerum. Bede the Venerable was the first Englishman to write about the weather in De natura rerum in 703. The work was a summary of then extant classical sources. However, Aristotle's works were largely lost until the 12th century, including Meteorologica. Isidore and Bede were scientifically minded, but they adhered to the letter of Scripture.
Islamic civilization translated many ancient works into Arabic which were transmitted and translated in western Europe to Latin.
In the 9th century, Al-Dinawari wrote the Kitab al-Nabat (Book of Plants), in which he deals with the application of meteorology to agriculture during the Arab Agricultural Revolution. He describes the meteorological character of the sky, the planets and constellations, the sun and moon, the lunar phases indicating seasons and rain, the anwa (heavenly bodies of rain), and atmospheric phenomena such as winds, thunder, lightning, snow, floods, valleys, rivers, lakes.