Interdisciplinary scientific study of the atmosphere focusing on weather forecasting
This article is about the study of weather. For the treatise by Aristotle, seeMeteorology (Aristotle). For the science of measurement, seeMetrology. For the study of meteors, seeMeteoritics.
Meteorology,climatology (long-term study and modelling of weather events),atmospheric physics (study of dynamics, thermodynamics and radiative transfer within atmosphere), andatmospheric chemistry (study ofair quality,aerosol interactions andpollutant dispersion) are sub-disciplines of theatmospheric sciences. The interactions between Earth's atmosphere and its oceans as part of a coupled ocean-atmosphere system (notablyEl Niño andLa Niña) are studied in the interdisciplinary field ofhydrometeorology, which draws from meteorology andhydrology. Other interdisciplinary areas includebiometeorology (weather's effects on living systems),space weather (solar activity's influence on Earth's upper atmosphere and technological infrastructure) and planetary meteorology (study of atmospheric phenomena on othercelestial bodies). An important branch of weather forecasting ismarine weather forecasting as it relates to maritime and coastal safety, in which weather effects also include atmospheric interactions with large bodies of water.
The study of meteorology dates backmillennia. Ancient civilizations, including Egyptians, Indians, Babylonians, and Greeks, attempted to predict weather through folklore, astrology, religious rituals, and early observations, resulting in the treatise namedMeteorology byAristotle, who is considered the founder of the discipline. After limited advancement during early medieval times, meteorology experienced a resurgence during theRenaissance. Figures likeAlhazen andDescartes challenged Aristotelian theories, emphasizingobservation andscientific methods. In the 18th century, accurate measurement tools (e.g. barometer and thermometer) made quantifiable atmospheric measurements possible and the first meteorological society (Societas Meteorologica Palatina) was founded. The 19th century saw modest progress in the field after weather observation networks were formed across broad regions with the help oftelegraph.[2] In the 20th century, the development ofnumerical weather prediction (NWP), coupled with advancements in satellite and radar technology, applied the laws offluid dynamics andthermodynamics to build sophisticated forecasting models.[3] The advent ofcomputers in the mid-20th century revolutionized forecasting, allowing for real-time processing of vast atmospheric datasets and automatic solution of modelling equations. 21st-century meteorology is driven bybig data andsupercomputing,[4] which dramatically improved prediction accuracy. Innovations likemachine learning,ensemble forecasting (running multiple model simulations with slightly varied initial conditions), and high-resolution global climate modeling[5] can enhance forecast precision.Climate change poses new challenges for forecasting and research as the frequency and intensity ofextreme weather events increase.[6] Furthermore, the atmosphere'schaotic nature, exemplified by thebutterfly effect, means inherent uncertainty remains.[7]
Early attempts at predicting weather were often related to prophecy anddivining, and were sometimes based on astrological ideas.Ancient religions believed meteorological phenomena to be under the control of the gods.[8] The ability to predictrains andfloods 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 onastrology and were practiced by priests. TheEgyptians hadrain-making rituals as early as 3500 BC.[8]
Ancient IndianUpanishads contain mentions of clouds andseasons.[9] The Samaveda mentions sacrifices to be performed when certain phenomena were noticed.[10]Varāhamihira's classical workBrihatsamhita, written about 500 AD,[9] provides evidence of weather observation.
Theancient Greeks were the first to make theories about the weather. Manynatural philosophers studied the weather. However, asmeteorological instruments did not exist, the inquiry was largely qualitative, and could only be judged by more general theoretical speculations.[11]Herodotus states thatThales predicted thesolar eclipse of 585 BC. He studied Babylonian equinox tables.[12] According to Seneca, he explained that the cause of theNile's annual floods was due to northerly winds hindering its descent by the sea.[13]Anaximander andAnaximenes 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.[14] A theory to explain summer hail was first proposed byAnaxagoras. 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.[15]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.[16]Hippocrates inquired into the effect of weather on health.Eudoxus claimed that bad weather followed four-year periods, according to Pliny.[17]
These early observations would form the basis forAristotle'sMeteorology, written in 350 BC.[18][19] Aristotle is considered the founder of meteorology.[20] One of the most impressive achievements described in theMeteorology is the description of what is now known as thehydrologic cycle. His work would remain an authority on meteorology for nearly 2,000 years.[21]
The bookDe Mundo (composed before 250 BC or between 350 and 200 BC) noted:[22]
If the flashing body is set on fire and rushes violently to the Earth it is called a thunderbolt; if it is only half of fire, but violent also and massive, it is called ameteor; if it is entirely free from fire, it is called a smoking bolt. They are all called 'swooping bolts' because they swoop down upon the Earth. Lightning is sometimes smoky and is then called 'smoldering lightning"; sometimes it darts quickly along and is then said to bevivid. At other times, it travels in crooked lines, and is calledforked lightning. When it swoops down upon some object it is called 'swooping lightning'
After Aristotle, progress in meteorology stalled for a long time.Theophrastus compiled a book on weather forecasting, called theBook of Signs, as well asOn Winds. He gave hundreds of signs for weather phenomena for a period up to a year.[23] 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.[24] 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.[25] The work of Theophrastus remained a dominant influence in weather forecasting for nearly 2,000 years.[26]
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 whenEratosthenes, according toProclus, 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.[27]
During the era ofRoman 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, butPosidonius 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 toAlexandria, home to the ancientLibrary of Alexandria. In the 2nd century AD,Ptolemy'sAlmagest dealt with meteorology, because it was considered a subset of astronomy. He gave several astrological weather predictions.[28] 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.[29] Ptolemy wrote on theatmospheric refraction of light in the context of astronomical observations.[30]
In 25 AD,Pomponius Mela, a Roman geographer, formalized the climatic zone system.[31] In 63–64 AD,Seneca wroteNaturales 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.[32] The second book(chapter) ofPliny'sNatural 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.[33]
From 400 to 1100, scientific learning in Europe was preserved by the clergy.Isidore of Seville devoted a considerable attention to meteorology inEtymologiae,De ordine creaturum andDe natura rerum.Bede the Venerable was the first Englishman to write about the weather inDe Natura Rerum in 703. The work was a summary of then extant classical sources. However, Aristotle's works were largely lost until the twelfth century, includingMeteorologica. Isidore and Bede were scientifically minded, butthey adhered to the letter of Scripture.[34]
In 1021,Alhazen showed that atmospheric refraction is also responsible fortwilight inOpticae thesaurus; he estimated that twilight begins when the sun is 19 degrees below thehorizon, and also used a geometric determination based on this to estimate the maximum possible height of theEarth's atmosphere as 52,000passim (about 49 miles, or 79 km).[38]
Adelard of Bath was one of the early translators of the classics. He also discussed meteorological topics in hisQuaestiones naturales. He thought dense air produced propulsion in the form of wind. He explained thunder by saying that it was due to ice colliding in clouds, and in Summer it melted. In the thirteenth century, Aristotelian theories reestablished dominance in meteorology. For the next four centuries, meteorological work by and large was mostlycommentary. It has been estimated over 156 commentaries on theMeteorologica were written before 1650.[39]
Experimental evidence was less important than appeal to the classics and authority in medieval thought. In the thirteenth century,Roger Bacon advocated experimentation and the mathematical approach. In hisOpus majus, he followed Aristotle's theory on the atmosphere being composed of water, air, and fire, supplemented by optics and geometric proofs. He noted that Ptolemy's climatic zones had to be adjusted fortopography.[40]
St. Albert the Great was the first to propose that each drop of falling rain had the form of a small sphere, and that this form meant that the rainbow was produced by light interacting with each raindrop.[41]Roger Bacon was the first to calculate the angular size of the rainbow. He stated that a rainbow summit cannot appear higher than 42 degrees above the horizon.[42]
By the middle of the sixteenth century, meteorology had developed along two lines: theoretical science based onMeteorologica, and astrological weather forecasting. The pseudoscientific prediction by natural signs became popular and enjoyed protection of the church and princes. This was supported by scientists likeJohannes Muller,Leonard Digges, andJohannes Kepler. However, there were skeptics. In the 14th century,Nicole Oresme believed that weather forecasting was possible, but that the rules for it were unknown at the time. Astrological influence in meteorology persisted until the eighteenth century.[44]
Gerolamo Cardano'sDe Subilitate (1550) was the first work to challenge fundamental aspects of Aristotelian theory. Cardano maintained that there were only three basic elements- earth, air, and water. He discounted fire because it needed material to spread and produced nothing. Cardano thought there were two kinds of air: free air and enclosed air. The former destroyed inanimate things and preserved animate things, while the latter had the opposite effect.[45]
Rene Descartes'sDiscourse on the Method (1637) typifies the beginning of thescientific revolution in meteorology. His scientific method had four principles: to never accept anything unless one clearly knew it to be true; to divide every difficult problem into small problems to tackle; to proceed from the simple to the complex, always seeking relationships; to be as complete and thorough as possible with no prejudice.[46]
In the appendixLes Meteores, he applied these principles to meteorology. He discussed terrestrial bodies and vapors which arise from them, proceeding to explain the formation of clouds from drops of water, and winds, clouds then dissolving into rain, hail and snow. He also discussed the effects of light on the rainbow. Descartes hypothesized that all bodies were composed ofsmall particles of different shapes and interwovenness. All of his theories were based on this hypothesis. He explained the rain as caused by clouds becoming too large for the air to hold, and that clouds became snow if the air was not warm enough to melt them, or hail if they met colder wind. Like his predecessors, Descartes's method was deductive, asmeteorological instruments were not developed and extensively used yet. He introduced theCartesian coordinate system to meteorology and stressed the importance of mathematics in natural science. His work established meteorology as a legitimate branch of physics.[47]
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. This century also saw the birth of the first meteorological society, the Societas Meteorologica Palatina in 1780.[48]
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. Additionally, scientists began to use mathematical models to make predictions about the weather. The 20th century saw the development of radar and satellite technology, which greatly improved the ability to observe and track weather systems. In addition, meteorologists and atmospheric scientists started to create the first weather forecasts and temperature predictions.[49]
In the 20th and 21st centuries, with the advent of computer models and big data, meteorology has become increasingly dependent on numerical methods and computer simulations. This has greatly improved weather forecasting and climate predictions. Additionally, meteorology has expanded to include other areas such as air quality, atmospheric chemistry, and climatology. The advancement in observational, theoretical and computational technologies has enabled ever more accurate weather predictions and understanding of weather pattern and air pollution. 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.[citation needed]
In 1648,Blaise Pascal rediscovered thatatmospheric pressure decreases with height, and deduced that there is a vacuum above the atmosphere.[57] In 1738,Daniel Bernoulli publishedHydrodynamics, initiating theKinetic theory of gases and established the basic laws for the theory of gases.[58] In 1761,Joseph Black discovered that ice absorbs heat without changing its temperature when melting. In 1772, Black's studentDaniel Rutherford discoverednitrogen, which he calledphlogisticated air, and together they developed thephlogiston theory.[59] In 1777,Antoine Lavoisier discoveredoxygen and developed an explanation for combustion.[60] In 1783, in Lavoisier's essay "Reflexions sur le phlogistique,"[61] he deprecates the phlogiston theory and proposes acaloric theory.[62][63] In 1804,John Leslie observed that a matte black surface radiates heat more effectively than a polished surface, suggesting the importance ofblack-body radiation. In 1808,John Dalton defended caloric theory inA New System of Chemistry and described how it combines with matter, especially gases; he proposed that theheat capacity of gases varies inversely withatomic weight. In 1824,Sadi Carnot analyzed the efficiency ofsteam engines using caloric theory; he developed the notion of areversible process and, in postulating that no such thing exists in nature, laid the foundation for thesecond law of thermodynamics. In 1716, Edmund Halley suggested thataurorae are caused by "magnetic effluvia" moving along theEarth's magnetic field lines.
In 1494,Christopher Columbus experienced a tropical cyclone, which led to the first written European account of a hurricane.[64] In 1686,Edmund Halley presented a systematic study of thetrade winds andmonsoons and identified solar heating as the cause of atmospheric motions.[65] In 1735, anideal explanation ofglobal circulation through study of thetrade winds was written byGeorge Hadley.[66] In 1743, whenBenjamin Franklin was prevented from seeing a lunar eclipse by ahurricane, he decided that cyclones move in a contrary manner to the winds at their periphery.[67] Understanding the kinematics of how exactly the rotation of the Earth affects airflow was partial at first. Gaspard-Gustave Coriolis published a paper in 1835 on the energy yield of machines with rotating parts, such as waterwheels.[68] In 1856,William Ferrel proposed the existence of acirculation cell in the mid-latitudes, and the air within deflected by the Coriolis force resulting in the prevailing westerly winds.[69] Late in the 19th century, the motion of air masses alongisobars was understood to be the result of the large-scale interaction of thepressure gradient force and the deflecting force. By 1912, this deflecting force was named the Coriolis effect.[70] Just after World War I, a group of meteorologists in Norway led byVilhelm Bjerknes developed theNorwegian cyclone model that explains the generation, intensification and ultimate decay (the life cycle) ofmid-latitude cyclones, and introduced the idea offronts, that is, sharply defined boundaries betweenair masses.[71] The group includedCarl-Gustaf Rossby (who was the first to explain the large scale atmospheric flow in terms offluid dynamics),Tor Bergeron (who first determined how rain forms) andJacob Bjerknes.
Cloud classification by altitude of occurrenceThis "Hyetographic or Rain Map of the World" was first published 1848 byAlexander Keith Johnston.This "Hyetographic or Rain Map of Europe" was also published in 1848 as part of "The Physical Atlas".
In the late 16th century and first half of the 17th century a range of meteorological instruments were invented – thethermometer,barometer,hydrometer, as well as wind and rain gauges. In the 1650s natural philosophers started using these instruments to systematically record weather observations. Scientific academies established weather diaries and organised observational networks.[72] In 1654,Ferdinando II de Medici established the firstweather observing network, that consisted of meteorological stations inFlorence,Cutigliano,Vallombrosa,Bologna,Parma,Milan,Innsbruck,Osnabrück, Paris andWarsaw. The collected data were sent to Florence at regular time intervals.[73] In the 1660sRobert Hooke of theRoyal Society of London sponsored networks of weather observers.Hippocrates' treatiseAirs, Waters, and Places had linked weather to disease. Thus early meteorologists attempted to correlate weather patterns with epidemic outbreaks, and the climate with public health.[72]
During theAge of Enlightenment meteorology tried to rationalise traditional weather lore, including astrological meteorology. But there were also attempts to establish a theoretical understanding of weather phenomena.Edmond Halley andGeorge Hadley tried to explaintrade winds. They reasoned that the rising mass of heated equator air is replaced by an inflow of cooler air from high latitudes. A flow of warm air at high altitude from equator to poles in turn established an early picture of circulation. Frustration with the lack of discipline among weather observers, and the poor quality of the instruments, led the early modernnation states to organise large observation networks. Thus, by the end of the 18th century, meteorologists had access to large quantities of reliable weather data.[72] In 1832, an electromagnetic telegraph was created byBaron Schilling.[74] The arrival of theelectrical telegraph in 1837 afforded, for the first time, a practical method for quickly gatheringsurface weather observations from a wide area.[75]
This data could be used to produce maps of the state of the atmosphere for a region near the Earth's surface and to study how these states evolved through time. To make frequent weather forecasts based on these data required a reliable network of observations, but it was not until 1849 that theSmithsonian Institution began to establish an observation network across the United States under the leadership ofJoseph Henry.[76] Similar observation networks were established in Europe at this time. The ReverendWilliam Clement Ley was key in understanding of cirrus clouds and early understandings ofJet Streams.[77]Charles Kenneth Mackinnon Douglas, known as 'CKM' Douglas read Ley's papers after his death and carried on the early study of weather systems.[78]Nineteenth century researchers in meteorology were drawn from military or medical backgrounds, rather than trained as dedicated scientists.[79] In 1854, the United Kingdom government appointedRobert FitzRoy to the new office ofMeteorological Statist to the Board of Trade with the task of gathering weather observations at sea. FitzRoy's office became theUnited Kingdom Meteorological Office in 1854, the second oldest national meteorological service in the world (theCentral Institution for Meteorology and Geodynamics (ZAMG) in Austria was founded in 1851 and is the oldest weather service in the world). The first daily weather forecasts made by FitzRoy's Office were published inThe Times newspaper in 1860. The following year a system was introduced of hoisting storm warning cones at principal ports when a gale was expected.
FitzRoy coined the term "weather forecast" and tried to separate scientific approaches from prophetic ones.[80]
A meteorologist at the console of the IBM 7090 in the Joint Numerical Weather Prediction Unit,c. 1965
In 1904, Norwegian scientistVilhelm Bjerknes first argued in his paperWeather Forecasting as a Problem in Mechanics and Physics that it should be possible to forecast weather from calculations based uponnatural laws.[86][87]
It was not until later in the 20th century that advances in the understanding of atmospheric physics led to the foundation of modernnumerical weather prediction. In 1922,Lewis Fry Richardson published "Weather Prediction By Numerical Process,"[88] 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. Richardson envisioned a large auditorium of thousands of people performing the calculations. However, the sheer number of calculations required was too large to complete without electronic computers, and the size of the grid and time steps used in the calculations led to unrealistic results. Though numerical analysis later found that this was due tonumerical instability.
Starting in the 1950s,numerical forecasts with computers became feasible.[89] The firstweather forecasts derived this way usedbarotropic (single-vertical-level) models, and could successfully predict the large-scale movement of midlatitudeRossby waves, that is, the pattern ofatmospheric lows andhighs.[90] In 1959, the UK Meteorological Office received its first computer, aFerranti Mercury.[91]
In the 1960s, thechaotic nature of the atmosphere was first observed and mathematically described byEdward Lorenz, founding the field ofchaos theory.[92] These advances have led to the current use ofensemble forecasting in most major forecasting centers, to take into account uncertainty arising from the chaotic nature of the atmosphere.[93] Mathematical models used to predict the long term weather of the Earth (climate models), have been developed that have a resolution today that are as coarse as the older weather prediction models. These climate models are used to investigate long-termclimate shifts, such as what effects might be caused by human emission ofgreenhouse gases.
Meteorologists are scientists who study and work in the field of meteorology.[94] The American Meteorological Society publishes and continually updates an authoritative electronicMeteorology Glossary.[95] Meteorologists work ingovernment agencies, private consulting andresearch services, industrial enterprises, utilities, radio andtelevision stations, and ineducation. In the United States, meteorologists held about 10,000 jobs in 2018.[96]
Although weather forecasts and warnings are the best known products of meteorologists for the public,weather presenters on radio and television are not necessarily professional meteorologists. They are most oftenreporters with little formal meteorological training, using unregulated titles such asweather specialist orweatherman. TheAmerican Meteorological Society andNational Weather Association issue "Seals of Approval" to weather broadcasters who meet certain requirements but this is not mandatory to be hired by the media.
Each science has its own unique sets of laboratory equipment. In the atmosphere, there are many things or qualities of the atmosphere that can be measured. Rain, which can be observed, or seen anywhere and anytime was one of the first atmospheric qualities measured historically. Also, two other accurately measured qualities are wind and humidity. Neither of these can be seen but can be felt. The devices to measure these three sprang up in the mid-15th century and were respectively therain gauge, the anemometer, and the hygrometer. Many attempts had been made prior to the 15th century to construct adequate equipment to measure the many atmospheric variables. Many were faulty in some way or were simply not reliable. EvenAristotle noted this in some of his work as the difficulty to measure the air.
Remote sensing, as used in meteorology, is the concept of collecting data from remote weather events and subsequently producing weather information. The common types of remote sensing areRadar,Lidar, andsatellites (orphotogrammetry). Each collects data about the atmosphere from a remote location and, usually, stores the data where the instrument is located. Radar and Lidar are not passive because both useEM radiation to illuminate a specific portion of the atmosphere.[98] Weather satellites along with more general-purpose Earth-observing satellites circling the earth at various altitudes have become an indispensable tool for studying a wide range of phenomena from forest fires toEl Niño.
The study of the atmosphere can be divided into distinct areas that depend on both time and spatial scales. At one extreme of this scale is climatology. In the timescales of hours to days, meteorology separates into micro-, meso-, and synoptic scale meteorology. Respectively, thegeospatial size of each of these three scales relates directly with the appropriate timescale.
Other subclassifications are used to describe the unique, local, or broad effects within those subclasses.
Microscale meteorology is the study of atmospheric phenomena on a scale of about 1 kilometre (0.62 mi) or less. Individual thunderstorms, clouds, and local turbulence caused by buildings and other obstacles (such as individual hills) are modeled on this scale.[100]Misoscale meteorology is an informal subdivision.
Mesoscale meteorology is the study of atmospheric phenomena that has horizontal scales ranging from 1 km to 1000 km and a vertical scale that starts at the Earth's surface and includes the atmospheric boundary layer, troposphere,tropopause, and the lower section of thestratosphere. 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 byIsidoro Orlanski.[101] Mesoscale timescales last from less than a day to multiple weeks. The events typically of interest arethunderstorms,squall lines,fronts,precipitation bands intropical andextratropical cyclones, and topographically generated weather systems such as mountain waves andsea and land breezes.[102]
Synoptic scale meteorology predicts atmospheric changes at scales up to 1000 km and 105 sec (28 days), in time and space. At the synoptic scale, theCoriolis acceleration acting on moving air masses (outside of the tropics) plays a dominant role in predictions. The phenomena typically described bysynoptic meteorology include events such as extratropical cyclones, baroclinic troughs and ridges,frontal zones, and to some extentjet streams. All of these are typically given onweather maps for a specific time. The minimum horizontal scale of synoptic phenomena is limited to the spacing betweensurface observation stations.[103]
Global scale meteorology is the study of weather patterns related to the transport of heat from thetropics to thepoles. Very large scale oscillations are of importance at this scale. These oscillations have time periods typically on the order of months, such as theMadden–Julian oscillation, or years, such as theEl Niño–Southern Oscillation and thePacific decadal oscillation. Global scale meteorology pushes into the range of climatology. The traditional definition of climate is pushed into larger timescales and with the understanding of the longer time scale global oscillations, their effect on climate and weather disturbances can be included in the synoptic and mesoscale timescales predictions.
Numerical Weather Prediction is a main focus in understanding air–sea interaction, tropical meteorology, atmospheric predictability, and tropospheric/stratospheric processes.[104] TheNaval Research Laboratory in Monterey, California, developed a global atmospheric model calledNavy Operational Global Atmospheric Prediction System (NOGAPS). NOGAPS is run operationally atFleet Numerical Meteorology and Oceanography Center for the United States Military. Many other global atmospheric models are run by national meteorological agencies.
Boundary layer meteorology is the study of processes in the air layer directly above Earth's surface, known as theatmospheric boundary layer (ABL). The effects of the surface – heating, cooling, andfriction – causeturbulent mixing within the air layer. Significant movement ofheat,matter, ormomentum on time scales of less than a day are caused by turbulent motions.[105] Boundary layer meteorology includes the study of all types of surface–atmosphere boundary, including ocean, lake, urban land and non-urban land for the study of meteorology.
Dynamic meteorology generally focuses on thefluid dynamics of the atmosphere. The idea ofair parcel is used to define the smallest element of the atmosphere, while ignoring the discrete molecular and chemical nature of the atmosphere. An air parcel is defined as an infinitesimal region in the fluidcontinuum of the atmosphere. The fundamental laws of fluid dynamics, thermodynamics, and motion are used to study the atmosphere. The physical quantities that characterize the state of the atmosphere are temperature, density, pressure, etc. These variables have unique values in the continuum.[99]
Forecast of surface pressures five days into the future for the north Pacific, North America, and north Atlantic Ocean
Weather forecasting is the application of science and technology to predict the state of theatmosphere at a future time and given location. Humans have attempted to predict the weather informally for millennia and formally since at least the 19th century.[106][107] Weather forecasts are made by collecting quantitativedata about the current state of the atmosphere and using scientific understanding of atmospheric processes to project how the atmosphere will evolve.[108]
Once an all-human endeavor based mainly upon changes inbarometric pressure, current weather conditions, and sky condition,[109][110]forecast models are now used to determine future conditions. Human input is still required to pick the best possible forecast model to base the forecast upon, which involves pattern recognition skills,teleconnections, knowledge of model performance, and knowledge of model biases. Thechaotic nature of the atmosphere, the massive computational power required to solve the equations that describe the atmosphere, error involved in measuring the initial conditions, and an incomplete understanding of atmospheric processes mean that forecasts become less accurate as the difference in current time and the time for which the forecast is being made (therange of the forecast) increases. The use of ensembles and model consensus help narrow the error and pick the most likely outcome.[111][112][113]
There are a variety of end uses to weather forecasts. Weather warnings are important forecasts because they are used to protect life and property.[114] Forecasts based on temperature andprecipitation are important to agriculture,[115][116][117][118] and therefore to commodity traders within stock markets. Temperature forecasts are used by utility companies to estimate demand over coming days.[119][120][121] On an everyday basis, people use weather forecasts to determine what to wear. Since outdoor activities are severely curtailed by heavy rain, snow, andwind chill, forecasts can be used to plan activities around these events, and to plan ahead and survive them.
Aviation meteorology deals with the impact of weather onair traffic management.[122] It is important for air crews to understand the implications of weather on their flight plan as well as their aircraft, as noted by theAeronautical Information Manual:[123]
The effects of ice on aircraft are cumulative—thrust is reduced, drag increases, lift lessens, and weight increases. The results are an increase in stall speed and a deterioration of aircraft performance. In extreme cases, 2 to 3 inches of ice can form on the leading edge of the airfoil in less than 5 minutes. 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.[124]
Meteorologists,soil scientists, agricultural hydrologists, andagronomists are people concerned with studying the effects of weather and climate on plant distribution,crop yield, water-use efficiency,phenology of plant and animal development, and the energy balance of managed and natural ecosystems. Conversely, they are interested in the role of vegetation on climate and weather.[125]
Hydrometeorology is the branch of meteorology that deals with thehydrologic cycle, the water budget, and the rainfall statistics ofstorms.[126] A hydrometeorologist prepares and issues forecasts of accumulating (quantitative) precipitation, heavy rain, heavy snow, and highlights areas with the potential for flash flooding. Typically the range of knowledge that is required overlaps with climatology, mesoscale and synoptic meteorology, and other geosciences.[127]
The multidisciplinary nature of the branch can result in technical challenges, since tools and solutions from each of the individual disciplines involved may behave slightly differently, be optimized for different hard- and software platforms and use different data formats. There are some initiatives – such as the DRIHM project[128] – that are trying to address this issue.[129]
Maritime meteorology deals with air and wave forecasts for ships operating at sea. Organizations such as theOcean Prediction Center, HonoluluNational Weather Service forecast office, United KingdomMet Office,KNMI andJMA prepare high seas forecasts for the world's oceans.
Environmental meteorology mainly analyzes industrial pollution dispersion physically and chemically based on meteorological parameters such as temperature, humidity, wind, and various weather conditions.
Meteorology applications in renewable energy includes basic research, "exploration," and potential mapping of wind power and solar radiation for wind and solar energy.
^Aristotle (2004) [350 BCE].Meteorology. The University of Adelaide Library, University of Adelaide, South Australia 5005. Archived fromthe original on 17 February 2007.Translated by E.W. Webster{{cite book}}: CS1 maint: location (link) CS1 maint: location missing publisher (link)
^Aristotle; Forster, E. S. (Edward Seymour), 1879–1950; Dobson, J. F. (John Frederic), 1875–1947 (1914).De Mundo. Oxford : The Clarendon Press. p. Chapter 4.{{cite book}}: CS1 maint: multiple names: authors list (link) CS1 maint: numeric names: authors list (link)
^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.
^abJacobson, Mark Z. (June 2005).Fundamentals of Atmospheric Modeling (paperback) (2nd ed.). New York: Cambridge University Press. p. 828.ISBN978-0-521-54865-6.
^Grigull, U., Fahrenheit, a Pioneer of Exact Thermometry. Heat Transfer, 1966, The Proceedings of the 8th International Heat Transfer Conference, San Francisco, 1966, Vol. 1.
^"Sur la combustion en général" ("On Combustion in general", 1777) and "Considérations Générales sur la Nature des Acides" ("General Considerations on the Nature of Acids", 1778).
^Johnson, Shaye (2003)."The Norwegian Cyclone Model"(PDF).weather.ou.edu. The University of Oklahoma. Archived fromthe original(PDF) on 1 September 2006. Retrieved11 October 2006.
^abcJohn L. Heilbron (2003).The Oxford Companion to the History of Modern Science. Oxford University Press. p. 518.ISBN9780199743766.
^Raymond S. Bradley, Philip D. Jones,Climate Since A.D. 1500, Routledge, 1992,ISBN0-415-07593-9, p.144
^Berknes, V. (1904) "Das Problem der Wettervorhersage, betrachtet vom Standpunkte der Mechanik und der Physik" (The problem of weather prediction, considered from the viewpoints of mechanics and physics),Meteorologische Zeitschrift,21 : 1–7. Available in English on-line at:Schweizerbart science publishersArchived 11 April 2018 at theWayback Machine.
^Richardson, Lewis Fry,Weather Prediction by Numerical Process (Cambridge, England: Cambridge University Press, 1922). Available on-line at:Internet Archive.org.
^Orlanski, Isidoro (1975). "A Rational Subdivision of Scales for Atmospheric Processes".Bulletin of the American Meteorological Society.56 (5):527–530.ISSN0003-0007.JSTOR26216020.
^Bluestein, H.,Synoptic-Dynamic Meteorology in Midlatitudes: Principles of Kinematics and Dynamics, Vol. 1, Oxford University Press, 1992;ISBN0-19-506267-1
^Wragg, David W. (1973).A Dictionary of Aviation (first ed.). Osprey. p. 190.ISBN9780850451634.
^An international version called theAeronautical Information Publication contains parallel information, as well as specific information on the international airports for use by the international community.
^Tsitskishvili, M. S.; Trusov, A. G. (February 1974). "Modern research in nuclear meteorology".Atomic Energy.36 (2):197–198.doi:10.1007/BF01117823.S2CID96128061.
Glossary of Meteorology. American Meteorological Society (2nd ed.). Allen Press. 2000.Archived from the original on 21 May 2006. Retrieved13 October 2004.{{cite book}}: CS1 maint: others (link)
Bluestein, H (1993) [1993].Synoptic-Dynamic Meteorology in Midlatitudes: Volume II: Observations and Theory of Weather Systems. Oxford University Press.ISBN978-0-19-506268-7.
Air Quality MeteorologyArchived 25 July 2009 at theWayback Machine – Online course that introduces the basic concepts of meteorology and air quality necessary to understand meteorological computer models. Written at a bachelor's degree level.
The GLOBE ProgramArchived 11 May 2023 at theWayback Machine – (Global Learning and Observations to Benefit the Environment) An international environmental science and education program that links students, teachers, and the scientific research community in an effort to learn more about the environment through student data collection and observation.
Glossary of MeteorologyArchived 13 May 2023 at theWayback Machine – From the American Meteorological Society, an excellent reference of nomenclature, equations, and concepts for the more advanced reader.
MeteorologyArchived 29 January 2018 at theWayback Machine, BBC Radio 4 discussion with Vladimir Janković, Richard Hambyn and Iba Taub (In Our Time, 6 March 2003)
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