Atmospheric sciences [cat.]
Meteorology [cat.] weather [cat.] tropical cyclones [cat.]
Climatology [cat.] climate [cat.] climate change [cat.]
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Meteorology (from Greek: μετέωρον, metéōron, "high in the sky"; and λόγος, lógos, "knowledge") is the interdisciplinary scientific study of the atmosphere that focuses on weather processes and forecasting (in contrast with climatology). Atmospheric sciences is an umbrella term for the study of the atmosphere, its processes the effects other systems have on the atmosphere and the effects of the atmosphere The weather is a set of all the phenomena occurring in a given Atmosphere at a given Time. A tropical cyclone is a storm system characterized by a low pressure center and numerous Thunderstorms that produce strong winds and Flooding Climatology (from Greek grc κλίμα klima, "region zone" and grc -λογία -logia) is the study of Climate, scientifically Climate encompasses the temperatures humidity rainfall atmospheric particle count and numerous other meteorogical factors in a given region over long periods of Climate change is any long-term significant change in the “average weather” that a given region experiences In Academia, Pedagogy, Physical sciences, Earth sciences, Human sciences and Social sciences Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five The weather is a set of all the phenomena occurring in a given Atmosphere at a given Time. Climatology (from Greek grc κλίμα klima, "region zone" and grc -λογία -logia) is the study of Climate, scientifically Meteorological phenomena are observable weather events which illuminate and are explained by the science of meteorology. A meteorological phenomenon is a Weather event which can be explained by the principles of Meteorology. Those events are bound by the variables that exist in Earth's atmosphere. EARTH was a short-lived Japanese vocal trio which released 6 singles and 1 album between 2000 and 2001 They are temperature, pressure, water vapor, and the gradients and interactions of each variable, and how they change in time. Temperature is a physical property of a system that underlies the common notions of hot and cold something that is hotter generally has the greater temperature Pressure (symbol 'p' is the force per unit Area applied to an object in a direction perpendicular to the surface General properties of water vapor Evaporation/sublimation Whenever a water molecule leaves a surface it is said to have evaporated The majority of Earth's observed weather is located in the troposphere. The troposphere is the lowest portion of Earth's atmosphere. It contains approximately 75% of the atmosphere's mass and almost all of its Water vapor and ^{[1] [2]}

Meteorology, climatology, atmospheric physics, and atmospheric chemistry are sub-disciplines of the atmospheric sciences. Climatology (from Greek grc κλίμα klima, "region zone" and grc -λογία -logia) is the study of Climate, scientifically Atmospheric physics is the application of Physics to the study of the atmosphere. Atmospheric chemistry is a branch of Atmospheric science in which the Chemistry of the Earth's atmosphere and that of other planets is studied Atmospheric sciences is an umbrella term for the study of the atmosphere, its processes the effects other systems have on the atmosphere and the effects of the atmosphere Meteorology and hydrology compose the interdisciplinary field of hydrometeorology. Hydrology (from Greek Yδωρ hudōr, "water" and λόγος logos, "study" is the study of the movement distribution and quality of Hydrometeorology is a branch of Meteorology and Hydrology that studies the transfer of Water and Energy between the land surface and the lower

Interactions between Earth's atmosphere and the oceans are part of coupled ocean-atmosphere studies. Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five Meteorology has application in many diverse fields such as the military, energy production, transport, agriculture and construction.

Contents 1 Sub-classifications 2 History 2.1 Observation networks and weather forecasting 2.2 Coriolis effect 2.3 Numerical weather prediction 3 Equipment 4 Weather forecasting 5 See also 6 References 7 Further reading 8 External links

Sub-classifications

In the study of the atmosphere, meteorology can be divided into distinct areas of emphasis depending on the temporal scope and spatial scope of interest. 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, the geospatial size of each of these three scales relates directly with the appropriate timescale. Geospatial is a term widely used to describe the combination of Spatial software and Analytical methods with terrestrial or Geographic datasets

Other subclassifications are available based on the need by humans, or by the unique, local or broad effects that are studied within that sub-class.

Boundary layer meteorology

Boundary layer meteorology is the study of processes in the air layer directly above Earth's surface, known as the atmospheric boundary layer (ABL) or peplosphere. In Physics and Fluid mechanics, a boundary layer is that layer of Fluid in the immediate vicinity of a bounding surface Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five EARTH was a short-lived Japanese vocal trio which released 6 singles and 1 album between 2000 and 2001 The planetary boundary layer ( PBL) also known as the atmospheric boundary layer ( ABL) or peplosphere, is the lowest part of the Atmosphere The effects of the surface – heating, cooling, and friction – cause turbulent mixing within the air layer. Friction is the Force resisting the relative motion of two Surfaces in contact or a surface in contact with a fluid (e In Fluid dynamics, turbulence or turbulent flow is a fluid regime characterized by chaotic Stochastic property changes Significant fluxes of heat, matter, or momentum on time scales of less than a day are advected by turbulent motions. In the various subfields of Physics, there exist two common usages of the term flux, both with rigorous mathematical frameworks Sensible heat is Potential energy in the form of thermal energy or Heat. Matter is commonly defined as being anything that has mass and that takes up space. In Classical mechanics, momentum ( pl momenta SI unit kg · m/s, or equivalently N · s) is the product ^[3] Boundary layer meteorology includes the study of all types of surface-atmosphere boundary, including ocean, lake, urban land and non-urban land.

Mesoscale meteorology

Mesoscale meteorology is the study of atmospheric phenomena that has horizontal scales ranging from microscale limits to synoptic scale limits and a vertical scale that starts at the Earth's surface and includes the atmospheric boundary layer, troposphere, tropopause, and the lower section of the stratosphere. Mesoscale Meteorology is the study of Weather systems smaller than Synoptic scale systems but larger than microscale and Storm-scale cumulus The troposphere is the lowest portion of Earth's atmosphere. It contains approximately 75% of the atmosphere's mass and almost all of its Water vapor and The tropopause is in the atmosphere between the Troposphere and the Stratosphere. The stratosphere is the second major layer of Earth's atmosphere, just above the Troposphere, and below the Mesosphere. Mesoscale timescales last from less than a day to the lifetime of the event, which in some cases can be weeks. 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. A squall line is a line of severe thunderstorms that can form along and/or ahead of a Cold front. A weather front is a boundary separating two masses of air of different densities, and is the principal cause of meteorological phenomena. A tropical cyclone is a storm system characterized by a low pressure center and numerous Thunderstorms that produce strong winds and Flooding Extratropical cyclones, sometimes called mid-latitude cyclones or wave cyclones, are a group of Cyclones defined as synoptic scale low ^[4]

Synoptic scale

Synoptic scale meteorology is generally large area dynamics referred to in horizontal coordinates and with respect to time. The synoptic scale in Meteorology (also known as large scale or cyclonic scale) is a horizontal length scale of the order of 1000 kilometres (about 620 The phenomena typically described by synoptic meteorology include events like extratropical cyclones, baroclinic troughs and ridges, frontal zones, and to some extent jets. The synoptic scale in Meteorology (also known as large scale or cyclonic scale) is a horizontal length scale of the order of 1000 kilometres (about 620 A weather front is a boundary separating two masses of air of different densities, and is the principal cause of meteorological phenomena. All of these are typically given on weather maps for a specific time. A weather map is a tool used to display information quickly showing the analysis of various meteorological quantities at various levels of the atmosphere The minimum horizontal scale of synoptic phenomena are limited to the spacing between surface observation stations. A weather station is a facility with instruments and equipment to make observations of atmospheric conditions in order to provide information to make weather forecasts ^[5]

Global scale

Global scale meteorology is study of weather patterns related to the transport of heat from the tropics to the poles. The Tropics are centered on the Equator and limited in Latitude by the Tropic of Cancer in the northern hemisphere at approximately 23°26' (23 A geographical pole, or geographic pole, is either of two fixed points on the surface of a spinning body or Planet, at 90 degrees from the Equator, based Also, very large scale oscillations are of importance. Those oscillations have time periods typically longer than a full annual seasonal cycle, such as ENSO, PDO, MJO, etc. El Niño-Southern Oscillation ( ENSO; commonly referred to as simply El Niño) is a global coupled ocean-atmosphere phenomenon The Pacific Decadal Oscillation (PDO is a pattern of Pacific Climate variability that shifts phases on at least inter-decadal time scale usually about 20 to 30 years Global scale pushes the thresholds of the perception of meteorology into climatology. The traditional definition of climate is pushed in to larger timescales with the further understanding of how the global oscillations cause both climate and weather disturbances in the synoptic and mesoscale timescales.

Numerical Weather Prediction is a main focus in understanding air-sea interaction, tropical meteorology, atmospheric predictability, and tropospheric/stratospheric processes. ^[6]. Currently (2007) Naval Research Laboratory in Monterey produces the atmospheric model called NOGAPS, a global scale atmospheric model, this model is run operationally at Fleet Numerical Meteorology and Oceanography Center. There are several other global atmospheric models.

Dynamic meteorology

Dynamic meteorology generally focuses on the physics of the atmosphere. Physics (Greek Physis - φύσις in everyday terms is the Science of Matter and its motion. The idea of air 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 an imaginary volume of air used by Meteorologists to conceptualize the Thermodynamic Fluid motions of the atmosphere for use An air parcel is defined as a point in the fluid continuum 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. ^[7]

Aviation meteorology

Aviation meteorology deals with the impact of weather on air traffic management. Air traffic control ( ATC) is a service provided by ground-based controllers who direct Aircraft on the ground and in the air It is important for air crews to understand the implications of weather on their flight plan as well as their aircraft, as noted by the Aeronautical Information Manual^[8]:

The effects of ice on aircraft are cumulative-thrust is reduced, drag increases, lift lessens, and weight increases. In United States Aviation, the Aeronautical Information Manual (AIM is the Federal Aviation Administration 's official guide to basic flight information The results are a decrease 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. ^[9]

Agricultural meteorology

Meteorologists, soil scientists, agricultural hydrologists, and agronomists are persons 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. Soil science is the study of Soil as a Natural resource on the surface of the Earth including soil formation, classification and mapping Agronomy is the science and technology of using plants for food fuel feed and fiber In Agriculture, crop yield (also known as "agricultural output" is not only a measure of the Yield of cereal per unit area of land under cultivation Phenology is the study of the times of recurring natural phenomena Conversely, they are interested in the role of vegetation on climate and weather. ^[10]

Hydrometeorology

Hydrometeorology is the branch of meteorology that deals with the hydrologic cycle, the water budget, and the rainfall statistics of storms. Hydrometeorology is a branch of Meteorology and Hydrology that studies the transfer of Water and Energy between the land surface and the lower The Earth 's Water is always in movement and the water cycle, also known as the hydrologic cycle, describes the continuous movement of water on above A storm is any disturbed state of an astronomical body's atmosphere, especially affecting its surface and strongly implying Severe weather. ^[11] 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. ^[12]

History

Main article: Timeline of meteorology

Observation networks and weather forecasting

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. The timeline of meteorology contains events of scientific and technological advancements in the area of Atmospheric sciences. The electrical telegraph is a telegraph that uses electric signals The electromagnetic telegraph is a device for human-to-human transmission Surface weather observations are the fundamental data used for safety as well as climatological reasons to forecast weather and issue warnings worldwide 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 the Smithsonian Institution began to establish an observation network across the United States under the leadership of Joseph Henry ^[13]. The Smithsonian Institution (smɪθsoʊnɪən is an educational and research institute and associated Museum complex administered and funded by the Government of The United States of America —commonly referred to as the Joseph Henry ( December 17 1797 &ndash May 13 1878) was an American scientist who served as the first Secretary of the Smithsonian Similar observation networks were established in Europe at this time. In 1854, the United Kingdom government appointed Robert FitzRoy to the new office of Meteorological Statist to the Board of Trade with the role of gathering weather observations at sea. The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located Vice-Admiral Robert FitzRoy ( 5 July 1805 – 30 April 1865) achieved lasting fame as the captain of HMS ''Beagle'' FitzRoy's office became the United Kingdom Meteorological Office in 1854, the first national meteorological service in the world. The first daily weather forecasts made by FitzRoy's Office were published in The Times newspaper in 1860. The Times is a daily national Newspaper published in the United Kingdom since 1785 when it was known as The Daily Universal Register. The following year a system was introduced of hoisting storm warning cones at principal ports when a gale was expected.

Over the next 50 years many countries established national meteorological services: Finnish Meteorological Central Office (1881) was formed from part of Magnetic Observatory of Helsinki University; India Meteorological Department (1889) established following tropical cyclone and monsoon related famines in the previous decades; United States Weather Bureau (1890) was established under the United States Department of Agriculture; Australian Bureau of Meteorology (1905) established by a Meteorology Act to unify existing state meteorological services. The University of Helsinki (Helsingin yliopisto Helsingfors universitet is a University located in Helsinki, Finland since 1829 but founded The India Meteorological Department (IMD also referred to as the Met Office is a Government of India organisation that is responsible for meteorological observations weather A monsoon is a seasonal prevailing wind which lasts for several months A famine is a widespread shortage of food that may apply to any Faunal species which phenomenon is usually accompanied by regional Malnutrition, Starvation The National Oceanic and Atmospheric Administration ( NOAA) is a scientific agency within the United States Department of Commerce focused on the conditions of the The Bureau of Meteorology is an Executive Agency of the Australian Government responsible for providing weather services to Australia and surrounding areas

Coriolis effect

Understanding the kinematics of how exactly the rotation of the Earth affects airflow was partial at first. Late in the 19th century the full extent of the large scale interaction of pressure gradient force and deflecting force that in the end causes air masses to move along isobars was understood. Early in the 20th century this deflecting force was named the Coriolis effect after Gaspard-Gustave Coriolis, who had published in 1835 on the energy yield of machines with rotating parts, such as waterwheels. In physics the Coriolis effect is an apparent deflection of moving objects when they are viewed from a Rotating frame of reference. Gaspard-Gustave de Coriolis or Gustave Coriolis (21 May 1792 – 19 September 1843 was a French Mathematician, Mechanical engineer and In 1856, William Ferrel proposed the existence of a circulation cell in the mid-latitudes with air being deflected by the Coriolis force to create the prevailing westerly winds. This page is about the meteorologist for the Comedian, see Will Ferrell. Atmospheric circulation is the large-scale movement of air and the means (together with the smaller Ocean circulation) by which Heat is distributed on the surface

Numerical weather prediction

In 1904, Norwegian scientist Vilhelm Bjerknes first postulated that prognostication of the weather is possible from calculations based upon natural laws. Vilhelm Friman Koren Bjerknes ( March 14, 1862 - April 9, 1951) was a Norwegian Physicist and Meteorologist A physical law or scientific law is a Scientific generalization based on empirical Observations of physical behavior (i

Early in the 20th century, advances in the understanding of atmospheric physics led to the foundation of modern numerical weather prediction. Numerical weather prediction uses current weather conditions as input into Mathematical models of the atmosphere to predict the weather. In 1922, Lewis Fry Richardson published "Weather prediction by numerical process," which described how small terms in the fluid dynamics equations governing atmospheric flow could be neglected to allow numerical solutions to be found. However, the sheer number of calculations required was too large to be completed without the use of computers.

At this time in Norway a group of meteorologists led by Vilhelm Bjerknes developed the model that explains the generation, intensification and ultimate decay (the life cycle) of mid-latitude cyclones, introducing the idea of fronts, that is, sharply defined boundaries between air masses. Vilhelm Friman Koren Bjerknes ( March 14, 1862 - April 9, 1951) was a Norwegian Physicist and Meteorologist Extratropical cyclones, sometimes called mid-latitude cyclones or wave cyclones, are a group of Cyclones defined as synoptic scale low A surface weather analysis is a special type of Weather map that provides a view of Weather elements over a geographical area at a specified time based on information For airmass in Astronomy, see Airmass. In Meteorology, an air mass is a large volume of Air that 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 the mechanism by which rain forms) and Jacob Bjerknes. Carl-Gustaf Arvid Rossby ( Stockholm 28 December, 1898 &ndash Stockholm 19 August, 1957) was a Swedish - U Fluid dynamics is the sub-discipline of Fluid mechanics dealing with fluid flow: Fluids ( Liquids and Gases in motion Tor Bergeron ( 1891 August 15 - 1977 June 13) is the Swedish Meteorologist who proposed a mechanism for the formation of Jacob Aall Bonnevie Bjerknes ( November 2, 1897, Stockholm Sweden &ndash July 7, 1975, Los Angeles California) was a

Starting in the 1950s, numerical experiments with computers became feasible. The 1950s Decade refers to the years of 1950 to 1959 inclusive A number is an Abstract object, tokens of which are Symbols used in Counting and measuring. The first weather forecasts derived this way used barotropic (that means, 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. Weather forecasting is the application of science and technology to predict the state of the atmosphere for a future time and a given location In Meteorology, a barotropic atmosphere is one in which the pressure depends only on the density and vice versa so that isobaric surfaces (constant pressure surfaces Rossby (or planetary) waves are giant Meanders in high-altitude winds that are a major influence on Weather. A low pressure area, or " low " is a region where the Atmospheric pressure is lower in relation to the surrounding area A high pressure area (also called a high or high-pressure is a region where the Atmospheric pressure is greater than surrounding areas

In the 1960s, the chaotic nature of the atmosphere was first observed and understood by Edward Lorenz, founding the field of chaos theory. Chaos (derived from the Ancient Greek, Chaos) typically refers to Unpredictability, and is the antithesis of Cosmos. Edward Norton Lorenz ( May 23, 1917) was an American Mathematician and meteorologist, and a pioneer of Chaos theory. In Mathematics, chaos theory describes the behavior of certain dynamical systems – that is systems whose state evolves with time – that may exhibit dynamics that These advances have led to the current use of ensemble forecasting in most major forecasting centers, to take into account uncertainty arising from the chaotic nature of the atmosphere. Ensemble forecasting is a numerical prediction method that is used to attempt to generate a representative sample of the possible future states of a dynamical system

Equipment

Main article: List of weather instruments

Generally speaking, each science has its own unique sets of laboratory equipment. This is a list of devices used for recording various aspects of the Weather. However, meteorology is a science which does not use much lab equipment but relies more on field-mode observation equipment. In some aspects this can make simple observations slide on the erroneous side.

In science, an observation, or observable, is an abstract idea that can be measured and data can be taken. 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 ones to be 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 the rain gauge, the anemometer, and the hygrometer. A rain gauge (also known as a udometer or a pluviometer or a cup) is a type of instrument used by meteorologists and Hydrologists An anemometer is a device for measuring wind speed and is one instrument used in a Weather station. Hygrometers are instruments used for measuring Humidity. A simple form of a hygrometer is specifically known as a "psychrometer" and consists of two Thermometers ^[14]

Sets of surface measurements are important data to meteorologists. They give a snapshot of a variety of weather conditions at one single location and are usually at a weather station, a ship or a weather buoy. A weather station is a facility with instruments and equipment to make observations of atmospheric conditions in order to provide information to make weather forecasts A ship /ʃɪp/ is a large vessel that floats on water Ships are generally distinguished from Boats based on size Weather buoys are instruments which collect Weather and Ocean data within the world's oceans The measurements taken at a weather station can include any number of atmospheric observables. Usually, temperature, pressure, wind measurements, and humidity are the variables that are measured by a thermometer, barometer, anemometer, and hygrometer, respectively. Temperature is a physical property of a system that underlies the common notions of hot and cold something that is hotter generally has the greater temperature Wind is the flow of Air or other Gases that compose an Atmosphere (including but not limited to the Earth's) Humidity is the amount of water vapor in the air In daily language the term "humidity" is normally taken to mean Relative humidity. The thermometer is a device that measures Temperature or Temperature gradient using a variety of different principles it comes from the Greek roots History The first barometer is thought to have been built unintentionally by Gasparo Berti, sometime between 1640 and 1643 An anemometer is a device for measuring wind speed and is one instrument used in a Weather station. Hygrometers are instruments used for measuring Humidity. A simple form of a hygrometer is specifically known as a "psychrometer" and consists of two Thermometers

Upper air data are of crucial importance for weather forecasting. The most widely used technique is launches of radiosondes. A radiosonde ( Sonde is French for Probe) is a unit for use in Weather balloons that measures various atmospheric parameters Supplementing the radiosondes a network of aircraft collection is organized by the World Meteorological Organization. Aircraft Meteorological Data Relay (AMDAR is a program initiated by the World Meteorological Organization.

Remote sensing, as used in meteorology, is the concept of collecting data from remote weather events and subsequently producing weather information. Remote sensing is the small or large-scale acquisition of information of an object or phenomenon by the use of either recording or real-time sensing device(s that is not in physical The common types of remote sensing are Radar, Lidar, and satellites (or photogrammetry). Radar is a system that uses electromagnetic waves to identify the range altitude direction or speed of both moving and fixed objects such as Aircraft, ships LIDAR ( Li ght D etection a nd R anging is an optical remote sensing technology that measures properties of scattered light to find range and/or This article is about artificial satellites For natural satellites also known as moons see Natural satellite. Photogrammetry is the first Remote sensing technology ever developed in which geometric properties about objects are determined from photographic images 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 use EM radiation to illuminate a specific portion of the atmosphere. Electromagnetic radiation takes the form of self-propagating Waves in a Vacuum or in Matter. ^[15]

The 1960 launch of the first successful weather satellite, TIROS-1, marked the beginning of the age where weather information became available globally. A weather satellite is a type of Satellite that is primarily used to monitor the Weather and Climate of the Earth. TIROS I (or TIROS-1) was the first successful Weather satellite, and the first of a series of Television Infrared Observation Satellites It was launched 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 to El Niño. El Niño-Southern Oscillation ( ENSO; commonly referred to as simply El Niño) is a global coupled ocean-atmosphere phenomenon

In recent years, climate models have been developed that feature a resolution comparable to older weather prediction models. This article is about the theories and mathematics of climate modeling These climate models are used to investigate long-term climate shifts, such as what effects might be caused by human emission of greenhouse gases. Climate encompasses the temperatures humidity rainfall atmospheric particle count and numerous other meteorogical factors in a given region over long periods of Greenhouse gases are gaseous constituents of the atmosphere bothnatural and anthropogenic that absorb and emit radiation at specific wavelengths within the spectrum of thermal infrared

Weather forecasting

Main article: Weather forecasting

Part of the Nature series on Weather
Seasons
Temperate Spring · Summer Autumn · Winter
Tropical Dry season Wet season
Storms
Thunderstorm · Tornado Tropical cyclone (Hurricane) Extratropical cyclone Winter storm · Blizzard Ice storm
Precipitation
Fog · Drizzle · Rain Freezing rain · Ice pellets Hail · Snow · Graupel
Topics
Meteorology Weather forecasting Climate · Air pollution
Weather Portal
v • d • e

Although meteorologists now rely heavily on computer models (numerical weather prediction), it is still relatively common to use techniques and conceptual models that were developed before computers were powerful enough to make predictions accurately or efficiently (generally speaking, prior to around 1980). Nature, in the broadest sense is equivalent to the natural world, physical universe, material world or material universe. The weather is a set of all the phenomena occurring in a given Atmosphere at a given Time. A season is one of the major divisions of the Year, generally based on yearly periodic changes in Weather. Spring is one of the four Temperate Seasons Spring marks the transition from Winter into Summer. Summer is one of the four Temperate Seasons Summer marks the warmest time of year with the longest days Autumn (also known as fall in North American English) is one of the four Temperate Seasons Autumn marks the transition from Summer Winter is one of the four Seasons of Temperate zones Calculated astronomically, it begins on the Solstice and ends on the Equinox The Tropics are centered on the Equator and limited in Latitude by the Tropic of Cancer in the northern hemisphere at approximately 23°26' (23 The dry season is a term commonly used when describing the weather in the Tropics. A wet season or rainy season is a Season in which the average Rainfall in a region is significantly increased A storm is any disturbed state of an astronomical body's atmosphere, especially affecting its surface and strongly implying Severe weather. A tornado is a violent rotating column of air which is in contact with both the surface of the earth and a Cumulonimbus cloud or in rare cases the base of a Cumulus A tropical cyclone is a storm system characterized by a low pressure center and numerous Thunderstorms that produce strong winds and Flooding Extratropical cyclones, sometimes called mid-latitude cyclones or wave cyclones, are a group of Cyclones defined as synoptic scale low A winter storm is an event in which the dominant varieties of precipitation are forms that only occur at cold Temperatures such as Snow or A blizzard is a severe Winter storm condition characterized by low Temperatures strong Winds and heavy blowing Snow Blizzards are formed when An ice storm is a type of Winter storm characterized by Freezing rain. In Meteorology, precipitation (also known as one class of hydrometeors, which are atmospheric water phenomena is any product of the condensation of atmospheric Fog is a cloud that is in contact with the ground Stratus clouds are usually the only clouds that touch the ground Drizzle (also called mizzle) is light precipitation consisting of liquid water drops smaller than that of Rain, and generally smaller than 0 Rain is Liquid precipitation. On Earth it is the condensation of atmospheric Water vapor into drops heavy enough to fall often making it to Freezing rain is a type of precipitation that begins as Snow at higher altitude falling from a Cloud towards earth melts completely on its way down while passing Ice pellets are a form of precipitation consisting of small Translucent ice balls Hail is a form of precipitation which consists of balls or irregular lumps of ice (hailstones "Snowfall" redirects here For other uses see Snow (disambiguation or Snowfall (disambiguation. Graupel (also called snow pellets) refers to precipitation that forms when supercooled Droplets of Water condense on a Snowflake forming This is a list of meteorology topics. The terms relate to Meteorology, the Interdisciplinary scientific study of the atmosphere that focuses on Weather forecasting is the application of science and technology to predict the state of the atmosphere for a future time and a given location Climate encompasses the temperatures humidity rainfall atmospheric particle count and numerous other meteorogical factors in a given region over long periods of Air pollution is the human introduction into the atmosphere of Chemicals Particulate matter, or Biological materials that cause harm or discomfort Numerical weather prediction uses current weather conditions as input into Mathematical models of the atmosphere to predict the weather. Many of these methods are used to determine how much skill a forecaster has added to the forecast (for example, how much better than persistence or climatology did the forecast do?). Similarly, they could also be used to determine how much skill the industry as a whole has gained with emerging technologies and techniques.

Persistence method

The persistence method assumes that conditions will not change. Often summarised as "Tomorrow equals today". This method works best over short periods of time in stagnant weather regimes. ^[16]

Extrapolation method

The extrapolation method assumes that atmospheric systems will propagate at similar speeds in the near future to those seen in the past. This method achieves the best results when diurnal changes in the pressure and precipitation patterns are taken into account.

Numerical forecasting method

The numerical weather prediction or NWP^[17] method uses computers to take into account a large number of variables and creates a computer model of the atmosphere. Numerical weather prediction uses current weather conditions as input into Mathematical models of the atmosphere to predict the weather. This is most successful when used with the methods below, and when model biases and relative skill are taken into account.

Consensus/ensemble methods of forecasting

Statistically, it is difficult to beat the mean solution, and the consensus and ensemble methods of forecasting take advantage of the situation by only favoring models that have the greatest support with their ensemble means or other pieces of global model guidance. A local Hydrometeorological Prediction Center study showed that using this method alone verifies 50-55% of the time. The Hydrometeorological Prediction Center (HPC is one of nine Service Centers under the umbrella of the National Centers for Environmental Prediction (NCEP operating under

Trends method

The trends method involves determining the change in fronts and high and low pressure centers in the model runs over various lengths of time. If the trend is seen over a long enough time frame (24 hours or so), it is more meaningful. The forecast models have been known to overtrend however, so use of this method verifies 55-60% the time, more so in the surface pattern than aloft. ^[18]

Climatology/Analog method

The climatology or analog method involves using historical weather data collected over long periods of time (years) to predict conditions on a given date. A variation on this theme is the use of teleconnections, which rely upon the date and the expected position of other positive or negative 500 hPa height anomalies to give someone an impression of what the overall pattern would look like with this anomaly in place, and is of more significant help than a model trend since it verifies roughly 75 percent of the time, when used properly and with a stable anomaly center. Teleconnection in Atmospheric science refers to climate anomalies being related to each other at large distances (typically thousands of kilometers Another variation is the use of standard deviations from climatology in various meteorological fields. Once the pattern deviates more than 4-5 sigmas from climatology, it becomes an improbable solution. ^[19]

See also

References

Further reading

• Byers, Horace. General Meteorology. New York: McGraw-Hill, 1994.

• Garret, J. R. [1992]. The atmospheric boundary layer. Cambridge University Press. ISBN 0-521-38052-9.  

• [2000] Glossary of Meteorology, American Meteorological Society, 2nd Ed. , Allen Press.  

• Bluestein, H [1992]. Synoptic-Dynamic Meteorology in Midlatitudes: Principles of Kinematics and Dynamics, Vol. 1. Oxford University Press. ISBN 0-19-506267-1.  

• Bluestein, H [1993]. Synoptic-Dynamic Meteorology in Midlatitudes: Volume II: Observations and Theory of Weather Systems. Oxford University Press. ISBN 0-19-506268-X.  

• Reynolds, R [2005]. Guide to Weather. Buffalo, New York: Firefly Books Inc, 208. ISBN 1-55407-110-0.  

• Holton, J. R. [2004]. An Introduction to Dynamic Meteorology, 4th Ed. , Burlington, Md: Elsevier Inc. . ISBN 0-12-354015-1.  

Links to other keywords in meteorology

Atmospheric conditions: Absolute stable air | Temperature inversion | Dine's compensation | precipitation | Cyclone | anticyclone | Thermal | Tropical cyclone (hurricane or typhoon) | Vertical draft | Extratropical cyclone Weather forecasting: atmospheric pressure | Low pressure area | High pressure area | dew point | weather front | jet stream | windchill | heat index | Theta-e | primitive equations | Pilot Reports Storm: thunderstorm | lightning | thunder | hail | tornado | convection | blizzard | supercell Climate: El Niño | monsoon | flood | drought | Global warming | Effect of sun angle on climate. The lapse rate is defined as the negative of the rate of change in an atmospheric variable usually Temperature, with height in an atmosphere In meteorology an inversion is a deviation from the normal change of an atmospheric property with altitude In Meteorology, Dine's compensation states that net mass convergence into a given column of air must be balanced by a net mass divergence from the same column of air In Meteorology, precipitation (also known as one class of hydrometeors, which are atmospheric water phenomena is any product of the condensation of atmospheric In Meteorology, a cyclone refers to an area of closed circular fluid motion rotating in the same direction as the Earth. In Meteorology, an anticyclone (that is opposite to a Cyclone) is a Weather phenomenon in which there is a descending movement of the air and A thermal column (or thermal) is a column of rising Air in the lower altitudes of the Earth's atmosphere. A tropical cyclone is a storm system characterized by a low pressure center and numerous Thunderstorms that produce strong winds and Flooding An updraft or downdraft ( air pocket) is the vertical movement of Air as a Weather related phenomenon Extratropical cyclones, sometimes called mid-latitude cyclones or wave cyclones, are a group of Cyclones defined as synoptic scale low Weather forecasting is the application of science and technology to predict the state of the atmosphere for a future time and a given location A low pressure area, or " low " is a region where the Atmospheric pressure is lower in relation to the surrounding area A high pressure area (also called a high or high-pressure is a region where the Atmospheric pressure is greater than surrounding areas The dew point (sometimes spelled dewpoint) is the Temperature to which a given parcel of Air must be cooled at constant Barometric pressure, A weather front is a boundary separating two masses of air of different densities, and is the principal cause of meteorological phenomena. Jet streams are fast flowing relatively narrow air currents found at the Tropopause, the transition between the Troposphere (where temperature decreases This page is for the movie "Wind Chill" For the term see Wind chill. The heat index ( HI) is an index that combines Air Temperature and Relative humidity in an attempt to determine the human-perceived equivalent Equivalent potential temperature, commonly referred to as Theta-e \left( \theta_e \right is a quantity related to the stability of a column of The primitive equations are a set of nonlinear differential equations that are used to approximate global atmospheric flow and are used in most atmospheric models A pilot report or PIREP is a report of actual Weather conditions encountered by an Aircraft in flight A storm is any disturbed state of an astronomical body's atmosphere, especially affecting its surface and strongly implying Severe weather. Lightning is an atmospheric discharge of Electricity, which typically occurs during Thunderstorms and sometimes during volcanic eruptions or Thunder is the sound made by Lightning. Depending on the nature of the lightning and distance of the listener it can range from a sharp Hail is a form of precipitation which consists of balls or irregular lumps of ice (hailstones A tornado is a violent rotating column of air which is in contact with both the surface of the earth and a Cumulonimbus cloud or in rare cases the base of a Cumulus Convection in the most general terms refers to the movement of molecules within Fluids (i A blizzard is a severe Winter storm condition characterized by low Temperatures strong Winds and heavy blowing Snow Blizzards are formed when A supercell is a severe thunderstorm with a deep continuously rotating updraft (a Mesocyclone) Climate encompasses the temperatures humidity rainfall atmospheric particle count and numerous other meteorogical factors in a given region over long periods of El Niño-Southern Oscillation ( ENSO; commonly referred to as simply El Niño) is a global coupled ocean-atmosphere phenomenon A monsoon is a seasonal prevailing wind which lasts for several months A flood is an overflow of an expanse of water that submerges land a deluge A drought is an extended period of months or years when a region notes a deficiency in its water supply Global warming is the increase in the average measured temperature of the The amount of heat energy received at any location on the globe is a direct effect of sun angle of climate, as the angle at which Sunlight strikes the earth Air Pollution: Air pollution dispersion modeling | Compilation of atmospheric dispersion models | Smog Other phenomena: deposition | dust devil | fog | tide | wind | cloud | air mass | evaporation | sublimation | ice | crepuscular rays | anticrepuscular rays Weather-related disasters: weather disasters | extreme weather Climatic or Atmospheric Patterns: Alberta clipper | El Niño | Derecho | Gulf Stream | La Niña | Jet stream | North Atlantic Oscillation | Madden-Julian oscillation | Pacific decadal oscillation | Pineapple Express | Sirocco | Siberian Express | Walker circulation

External links

Please see weather forecasting for weather forecast sites. Air pollution is the human introduction into the atmosphere of Chemicals Particulate matter, or Biological materials that cause harm or discomfort Atmospheric dispersion modeling is the mathematical simulation of how air pollutants disperse in the ambient atmosphere. Atmospheric dispersion models are computer programs that use mathematical Algorithms to simulate how Pollutants in the ambient atmosphere disperse Smog is a kind of Air pollution; the word "smog" is a Portmanteau of Smoke and Fog. Deposition is a process in which gas transforms into solid (also known as desublimation A dust devil is a strong well-formed and relatively long-lived whirlwind, ranging from small (half a meter wide and a few meters tall to large (over 10 meters wide and over Fog is a cloud that is in contact with the ground Stratus clouds are usually the only clouds that touch the ground Characteristics A tide is a repeated cycle of sea level changes in the following stages Over several hours the water rises or advances up a beach in the flood Wind is the flow of Air or other Gases that compose an Atmosphere (including but not limited to the Earth's) A cloud is a visible mass of droplets or frozen crystals floating in the atmosphere above the surface of the Earth or another Planetary body For airmass in Astronomy, see Airmass. In Meteorology, an air mass is a large volume of Air that Evaporation is the process by which Molecules in a Liquid state (e Sublimation of an element or compound is a transition from the Solid to Gas phase with no intermediate liquid stage Ice is a Solid phase, usually crystalline, of a Non-metalic substance that is liquid or gas at Room temperature, such as Ammonia Crepuscular rays, in atmospheric Optics, also known as sun rays, cloud breaks, sunburst, God's rays, Fingers of God Anticrepuscular rays are similar to Crepuscular rays, but seen opposite the sun in the sky Weather disasters are Natural disasters caused by rain drought snow extreme heat or cold ice or wind See also List of extreme weather events Extreme weather includes Weather phenomena that are at the extremes of the historical distribution especially Alberta clipper (also known as a Canadian Clipper) is a fast moving Low pressure area which generally affects the central provinces of Canada El Niño-Southern Oscillation ( ENSO; commonly referred to as simply El Niño) is a global coupled ocean-atmosphere phenomenon derecho ( from Spanish: " derecho " meaning "right" is a widespread and long-lived violent convectively induced straight-line windstorm that is The Gulf Stream, together with its northern extension towards Europe the North Atlantic Drift, is a powerful warm and swift Atlantic Ocean current that El Niño-Southern Oscillation ( ENSO; commonly referred to as simply El Niño) is a global coupled ocean-atmosphere phenomenon Jet streams are fast flowing relatively narrow air currents found at the Tropopause, the transition between the Troposphere (where temperature decreases The North Atlantic oscillation (NAO is a climatic phenomenon in the North Atlantic Ocean of fluctuations in the difference of Sea-level pressure between The Pacific Decadal Oscillation (PDO is a pattern of Pacific Climate variability that shifts phases on at least inter-decadal time scale usually about 20 to 30 years Pineapple Express (also known as Pineapple Connection) is a non-technical shorthand term popular in the news media for a meteorological phenomenon which is characterized by Sirocco, scirocco, jugo or rarely siroc is a Mediterranean Wind that comes from Siberian Express is a shorthand meteorological term in the United States describing the arrival of an extremely cold Air mass of Arctic origins The Walker circulation (or Walker cell is an idealized air flow which forms on average Zonal Atmospheric circulation of air at the Equator and Weather forecasting is the application of science and technology to predict the state of the atmosphere for a future time and a given location

• Air Quality Meteorology - 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 Program - (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 Meteorology - From the American Meteorological Society, an excellent reference of nomenclature, equations, and concepts for the more advanced reader.
• JetStream - An Online School for Weather - National Weather Service
• Learn About Meteorology - Australian Bureau of Meteorology
• Meteorology Education and Training (MetEd) - The COMET Program
• NOAA Central Library - National Oceanic & Atmospheric Administration
• The World Weather 2010 Project The University of Illinois at Urbana-Champaign
• NOAA Weather Navigator Plot and download archived data from thousands of worldwide weather stations
• Ogimet - online data from meteorological stations of the world, obtained through NOAA free services

Satellite imagery:

• Geostationary Satellite Imagery - NOAA National Environmental Satellite, Data, and Information Service
• Satellite Imagery - UK Met Office

Base Reflectivity (Radar):

• Find and click with NWS
• Reflectivity mosaic

Meteorology during Solar Eclipse

• Solar Eclipse Meteorological Measurement

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