There are four main scales, or sizes of systems, dealt with in meteorology: the macroscale, the synoptic scale, the mesoscale, and the microscale. The macroscale deals with systems with global size, such as the Madden–Julian oscillation. Synoptic scale systems cover a portion of a continent, such as extratropical cyclones, with dimensions of across. The mesoscale is the next smaller scale, and often is divided into two ranges: meso-alpha phenomena range from across (the realm of the tropical cyclone), while meso-beta phenomena range from across (the scale of the mesocyclone). The microscale is the smallest of the meteorological scales, with a size under (the scale of tornadoes and waterspouts).
Meteorological scales
Cyclogenesis
Cyclogenesis | Meteorological scales
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we would expect what with low pressure in the northern hemisphere
user
234 significant extratropical cyclones form each winter
assistant
how does a low pressure area form?
user
Cyclogenesis is the development and strengthening of cyclonic circulations
assistant
what does the first word mean?
user
It  is the development and strengthening of cyclonic circulations in the atmosphere results in the formation of low pressure area
assistant
how is this associated with the weather?
user
Sorry. I cannot find the answer based on the context.
assistant
what are some of its related terms?
user
It is the opposite of cyclolysis
assistant
which scaled are used to measure it?
user
The macroscale, the synoptic scale, the mesoscale, and the microscale
assistant
what does the first one do?
user
It deals with systems with global size, such as the Madden–Julian oscillation
assistant
who invented the second one?
user
These horizontal dimensions are not rigid divisions but instead reflect typical sizes of phenomena having certain dynamic characteristics. For example, a system does not necessarily transition from meso-alpha to synoptic scale when its horizontal extent grows from .
Cyclogenesis | Meteorological scales
There are four main scales, or sizes of systems, dealt with in meteorology: the macroscale, the synoptic scale, the mesoscale, and the microscale. The macroscale deals with systems with global size, such as the Madden–Julian oscillation. Synoptic scale systems cover a portion of a continent, such as extratropical cyclones, with dimensions of across. The mesoscale is the next smaller scale, and often is divided into two ranges: meso-alpha phenomena range from across (the realm of the tropical cyclone), while meso-beta phenomena range from across (the scale of the mesocyclone). The microscale is the smallest of the meteorological scales, with a size under (the scale of tornadoes and waterspouts).
Cyclogenesis | Meteorological scales
In 1714, Gabriel Fahrenheit created a reliable scale for measuring temperature with a mercury-type thermometer. In 1742, Anders Celsius, a Swedish astronomer, proposed the "centigrade" temperature scale, the predecessor of the current Celsius scale. In 1783, the first hair hygrometer was demonstrated by Horace-Bénédict de Saussure. In 1802–1803, Luke Howard wrote "On the Modification of Clouds", in which he assigns cloud types Latin names. In 1806, Francis Beaufort introduced his system for classifying wind speeds. Near the end of the 19th century the first cloud atlases were published, including the "International Cloud Atlas", which has remained in print ever since.
Meteorology | Instruments and classification scales
In 1441, king Sejong's son, Prince Munjong, invented the first standardized rain gauge. These were sent throughout the Joseon Dynasty of Korea as an official tool to assess land taxes based upon a farmer's potential harvest. In 1450, Leone Battista Alberti developed a swinging-plate anemometer, and is known as the first "anemometer". In 1607, Galileo Galilei constructs a thermoscope. In 1643, Evangelista Torricelli invents the mercury barometer. In 1662, Sir Christopher Wren invented the mechanical, self-emptying, tipping bucket rain gauge. In 1714, Gabriel Fahrenheit creates a reliable scale for measuring temperature with a mercury-type thermometer. In 1742, Anders Celsius, a Swedish astronomer, proposed the 'centigrade' temperature scale, the predecessor of the current Celsius scale.
Meteorological instrumentation | History of meteorological instrument
Versions designed for climate applications with time scales of decades to centuries were originally created in 1969 by Syukuro Manabe and Kirk Bryan at the Geophysical Fluid Dynamics Laboratory in Princeton, New Jersey. When run for multiple decades, computational limitations mean that the models must use a coarse grid that leaves smaller-scale interactions unresolved.
Numerical weather prediction | Climate modeling
Kerry Emanuel created a mathematical model around 1988 to compute the upper limit of tropical cyclone intensity based on sea surface temperature and atmospheric profiles from the latest global model runs. Emanuel's model is called the "maximum potential intensity", or MPI. Maps created from this equation show regions where tropical storm and hurricane formation is possible, based upon the thermodynamics of the atmosphere at the time of the last model run. This does not take into account vertical wind shear.
Tropical cyclogenesis | Role of Maximum Potential Intensity (MPI)
In 1441, King Sejong's son, Prince Munjong of Korea, invented the first standardized rain gauge. These were sent throughout the Joseon dynasty of Korea as an official tool to assess land taxes based upon a farmer's potential harvest. In 1450, Leone Battista Alberti developed a swinging-plate anemometer, and was known as the first "anemometer". In 1607, Galileo Galilei constructed a thermoscope. In 1611, Johannes Kepler wrote the first scientific treatise on snow crystals: "Strena Seu de Nive Sexangula (A New Year's Gift of Hexagonal Snow)." In 1643, Evangelista Torricelli invented the mercury barometer. In 1662, Sir Christopher Wren invented the mechanical, self-emptying, tipping bucket rain gauge.
Meteorology | Instruments and classification scales
The Norwegian cyclone model is an idealized formation model of cold-core cyclonic storms developed by Norwegian meteorologists during the First World War. The main concept behind this model, relating to cyclogenesis, is that cyclones progress through a predictable evolution as they move up a frontal boundary, with the most mature cyclone near the northeast end of the front and the least mature near the tail end of the front.
Cyclogenesis | Norwegian cyclone model
Climate cycles such as ENSO and the Madden–Julian oscillation modulate the timing and frequency of tropical cyclone development. There is a limit on tropical cyclone intensity which is strongly related to the water temperatures along its path.
Tropical cyclogenesis | Introduction
In 1956, Charney left IAS to become a professor of meteorology and director of the Atmospheric and Ocean Dynamics Project at MIT, where for 25 years he contributed major contributions in dynamic meteorology and oceanography research, including large-scale atmospheric turbulence, feedback interactions between the oceans and atmosphere, the persistence of certain abnormal flow patterns in the atmosphere, and the relationship of such phenomena to droughts. Among his many fundamental contributions to the field, Charney identified “baroclinic instability,” the first convincing physical explanation for the development of mid-latitude cyclones. Charney identified the mechanism that explains the size, structure, and growth rate of mid-latitude weather systems, and is a ubiquitous phenomenon in rotating, stratified fluids like our oceans and atmosphere.
Jule Gregory Charney | Dynamic meteorology and oceanography
An inverse relationship exists between tropical cyclone activity in the western north Pacific basin and the north Atlantic basin, however. When one basin is active, the other is normally quiet, and vice versa. The main reason for this appears to be the phase of the MJO, which is normally in opposite modes between the two basins at any given time. While this relationship appears robust, the MJO is one of many factors that contribute to the development of tropical cyclones. For example, sea surface temperatures must be sufficiently warm and vertical wind shear must be sufficiently weak for tropical disturbances to form and persist.
Madden–Julian oscillation | Influence on tropical cyclogenesis
Paul Rowland Julian (born October 12, 1929), a Fellow of the American Meteorological Society, is an American meteorologist who served as a longtime staff scientist at the National Center for Atmospheric Research (NCAR), was co-author with Roland Madden of the study establishing the Madden–Julian oscillation (MJO), and contributed to the international, multi-institutional Global Atmospheric Research Program (GARP), Tropical Wind, Energy Conversion, and Reference Level Experiment (TWERLE), and Tropical Ocean-Global Atmosphere (TOGA) meteorology research programs. The MJO meteorologic phenomenon he co-discovered is the largest element of the intraseasonal variability in the tropical atmosphere, a traveling pattern arising from large-scale coupling between atmospheric circulation and tropical deep convection.
Paul Julian (meteorologist) | Introduction
Douglass found that tree rings could track past climatic changes but these were thought to only show random variations in the local region. It was only in the 1960s that accurate use of tree rings as climate proxies for reconstructions was pioneered by Harold C. Fritts. In 1965 Hubert Lamb, a pioneer of historical climatology, generalised from temperature records of central England by using historical, botanical and archeological evidence to popularise the idea of a Medieval Warm Period from around 900 to 1300, followed by a cold epoch culminating between 1550 and 1700. In 1972 he became the founding director of the Climatic Research Unit (CRU) in the University of East Anglia (UEA), which aimed to improve knowledge of climate history in both the recent and far distant past, monitor current changes in global climate, identify processes causing changes at different timescales, and review the possibility of advising about future trends in climate.
Hockey stick graph | Origins: the first paleoclimate reconstructions
However, the MJO also influences these conditions that facilitate or suppress tropical cyclone formation. The MJO is monitored routinely by both the USA National Hurricane Center and the USA Climate Prediction Center during the Atlantic hurricane (tropical cyclone) season to aid in anticipating periods of relative activity or inactivity.
Madden–Julian oscillation | Influence on tropical cyclogenesis
However, due to the low skill showed by the thermotropic model, the JNWPU reverted to the single-layer barotropic model in 1958. The Japanese Meteorological Agency became the third organization to initiate operational numerical weather prediction in 1959. The first real-time forecasts made by Australia's Bureau of Meteorology in 1969 for portions of the Southern Hemisphere were also based on the single-layer barotropic model. Later models used more complete equations for atmospheric dynamics and thermodynamics. In 1959, Karl-Heinz Hinkelmann produced the first reasonable primitive equation forecast, 37 years after Richardson's failed attempt. Hinkelmann did so by removing small oscillations from the numerical model during initialization.
History of numerical weather prediction | Early years
In 1955-56, Smagorinsky collaborated with John von Neumann, Jule Charney, and Norman Phillips to develop a 2-level, zonal hemispheric model using a subset of the primitive equations. Beginning in 1959, he proceeded to develop a nine-level primitive-equation General Circulation Model (still hemispheric). By the end of the next decade, GCMs emerged globally as a central tool in climate research. Other researchers who worked with Smagorinsky in Washington and Princeton included Isidoro Orlanski, Jerry Mahlman, Syukuro Manabe, Yoshio Kurihara, Kikuro Miyakoda, Rod Graham, Leith Holloway, Isaac Held, Garreth Williams, George Philander, and Douglas Lilly.
Joseph Smagorinsky | Leadership of Geophysical Fluid Dynamics Laboratory
Julian and Roland A. Madden co-authored a 1971 research publication entitled "Detection of a 40-50 day oscillation in the zonal wind in the tropical Pacific", which became the basis of the accepted Madden–Julian oscillation (MJO), a theory that remains in teaching and practice in climate research. The MJO is the largest element of intraseasonal variability of the atmosphere in the tropics; it is a traveling pattern arising from large-scale coupling between atmospheric circulation and tropical deep convection. (The El Niño–Southern Oscillation is a related phenomenon, but a standing pattern.) The ability to identify and forecast the MJO "is of considerable importance" in the ability of meteorologists to predict short-term variability in climate, and to perform long-term predictions of tropical and subtropical weather based on modeling.
Paul Julian (meteorologist) | Discovery of the Madden-Julian Oscillation
Vilhelm Bjerknes began the modern development of the general circulation model in the early 20th century. The progress of numerical modeling was slow due to the slow speed of early computers and the lack of adequate observations. It wasn't until the 1950s that the numerical models were getting close to being realistic. Hansen's first contribution to numerical climate models came with the 1974 publication of the GISS model. He and his colleagues claimed that the model was successful in simulating the major features of sea-level pressure and 500mb heights in the North American region. A 1981 "Science" publication by Hansen and a team of scientists at Goddard concluded that carbon dioxide in the atmosphere would lead to warming sooner than previously predicted.
James Hansen | Climate model development and projections
His major contribution was the primitive equations which are used in climate models. It was this work that inspired both V. Walfrid Ekman and Carl-Gustav Arvid Rossby to apply it to large-scale motions in the oceans and atmosphere and to make modern weather forecasting feasible. Bjerknes himself had foreseen the possible applications as early as 1904. This attack upon the meteorological problems from a hydrodynamical point of view was after 1906 supported by the Carnegie Institution of Washington, D.C., of which he became a research associate. Two introductory volumes, "Statics and Kinematics", of a greater work, "Dynamic Meteorology and Hydrography", were published in 1913 under the auspices of the Institution.
Vilhelm Bjerknes | Life and career
In the United Kingdom the Meteorological Office first numerical weather prediction was completed by F. H. Bushby and Mavis Hinds in 1952 under the guidance of John Sawyer. These experimental forecasts were generated using a 12 × 8 grid with a grid spacing of 260 km, a one-hour time-step, and required four hours of computing time for a 24-hour forecast on the EDSAC computer at the University of Cambridge and the LEO computer developed by J. Lyons and Co. Following these initial experiments, work moved to the Ferranti Mark 1 computer at the Manchester University Department of Electrical Engineering and in 1959 a Ferranti Mercury computer, known as 'Meteor', was installed at the Met Office.
History of numerical weather prediction | Background
Misoscale is an unofficial scale of meteorological phenomena that ranges in size from 40 meters to about 4 kilometers. This scale was proposed by Ted Fujita, the father of the Fujita scale, to classify phenomenon of the order of the rotation within a thunderstorm, the scale of the funnel cloud of a tornado, and the size of the swath of destruction of a microburst. It is a subdivision of the microscale.
Misoscale meteorology | Introduction
Gaspard-Gustave Coriolis published a paper in 1835 on the energy yield of machines with rotating parts, such as waterwheels. In 1856, William Ferrel proposed the existence of a circulation cell in the mid-latitudes, and the air within deflected by the Coriolis force resulting in the prevailing westerly winds. Late in the 19th century, the motion of air masses along isobars was understood to be the result of the large-scale interaction of the pressure gradient force and the deflecting force. By 1912, this deflecting force was named the Coriolis effect. Just after World War I, a group of meteorologists in Norway led by Vilhelm Bjerknes developed the Norwegian cyclone model that explains the generation, intensification and ultimate decay (the life cycle) of mid-latitude cyclones, and introduced the idea of fronts, that is, sharply defined boundaries between air masses.
Meteorology | Research into cyclones and air flow
The Renaissance brought significant development of instruments to measure atmospheric phenomena and scales to compare them. Subsequent developments in atmospheric science in the 18th Century confirmed the need for widespread measurement and uniform transnational measurement scales. In the early 19th Century countries began to share meteorological data, and on this basis a conference was held in Cambridge in 1845 with representation by the leading British and European meteorologists, including: Matthew Fontaine Maury, of the US Navy, initiated the convening of the first true International Meteorological conference from late August through early September 1853. The Conference opened its proceedings at Brussels, Belgium, on the 23d August 1853, in the residence of M.
International Meteorological Organization | History
In 1783, the first hair hygrometer is demonstrated by Horace-Bénédict de Saussure. In 1806, Francis Beaufort introduced his system for classifying wind speeds. The April 1960 launch of the first successful weather satellite, TIROS-1, marked the beginning of the age where weather information became available globally. This was also used to measure the temperature of the surrounding air.
Meteorological instrumentation | History of meteorological instrument
One of the earliest type of calculations resembling modern CFD are those by Lewis Fry Richardson, in the sense that these calculations used finite differences and divided the physical space in cells. Although they failed dramatically, these calculations, together with Richardson's book "Weather prediction by numerical process", set the basis for modern CFD and numerical meteorology. In fact, early CFD calculations during the 1940s using ENIAC used methods close to those in Richardson's 1922 book.
Computational fluid dynamics | Background and history
The group included Carl-Gustaf Rossby (who was the first to explain the large scale atmospheric flow in terms of fluid dynamics), Tor Bergeron (who first determined how rain forms) and Jacob Bjerknes.
Meteorology | Research into cyclones and air flow
In 1956, Norman A. Phillips developed a mathematical model which could realistically depict monthly and seasonal patterns in the troposphere, which became the first successful climate model. Following Phillips's work, several groups began working to create general circulation models. The first general circulation climate model that combined both oceanic and atmospheric processes was developed in the late 1960s at the NOAA Geophysical Fluid Dynamics Laboratory. By the early 1980s, the United States' National Center for Atmospheric Research had developed the Community Atmosphere Model; this model has been continuously refined into the 2000s. In 1986, efforts began to initialize and model soil and vegetation types, which led to more realistic forecasts.
History of numerical weather prediction | Global climate models
During the first half of the twentieth century, the astronomer A. E. Douglass founded the Laboratory of Tree-Ring Research at the University of Arizona. Douglass sought to better understand cycles of sunspot activity and reasoned that changes in solar activity would affect climate patterns on earth, which would subsequently be recorded by tree-ring growth patterns ("i.e.", sunspots → climate → tree rings).
Dendrochronology | History
In the second week of June, a large cyclonic gyre developed in the western Caribbean Sea during a positive phase of the Madden–Julian oscillation. Convection was enhanced by two tropical waves, with the first emerging into the Atlantic Ocean from the west coast of Africa on June 4 and reached the gyre between June 14 and June 15. As early as June 13, the National Hurricane Center (NHC) anticipated that a broad low pressure area would develop in the northwestern Caribbean Sea, which had the potential for tropical cyclogenesis. The second tropical wave began interacting with the gyre on June 17, resulting in the development of a broad low pressure area later that day.
Tropical Storm Cindy (2017) | Meteorological history
In 1956, Norman Phillips developed a mathematical model that could realistically depict monthly and seasonal patterns in the troposphere. It became the first successful climate model. Following Phillips's work, several groups began working to create GCMs. The first to combine both oceanic and atmospheric processes was developed in the late 1960s at the NOAA Geophysical Fluid Dynamics Laboratory. By the early 1980s, the United States' National Center for Atmospheric Research had developed the Community Atmosphere Model; this model has been continuously refined. In 1996, efforts began to model soil and vegetation types. Later the Hadley Centre for Climate Prediction and Research's HadCM3 model coupled ocean-atmosphere elements.
General circulation model | History
Among Dr. Smagorinsky's many talents was attracting creative scientists to the staff of the GFDL. Two of them were climate modeler Syukuro Manabe in 1959 and ocean modeler Kirk Bryan in 1961, who spearheaded the development of the first climate model in 1969, a general circulation model that was the first approach to take into account the interactions of oceans and atmosphere. Smagorinsky assigned Manabe to the General Circulation Model (GCM) coding and development effort. By 1963, Smagorinsky, Manabe, and their collaborators had completed a nine-level, hemispheric primitive-equation General Circulation Model. Manabe was given a large programming staff and was thus able to focus on mathematical structure of the models, without becoming overly involved in coding.
Joseph Smagorinsky | Leadership of Geophysical Fluid Dynamics Laboratory
Both of these two atmospheric scientists continued research on the MJO phenomenon throughout their careers, and it has continued to be broadly referenced and studied into the new millennium.
Paul Julian (meteorologist) | Discovery of the Madden-Julian Oscillation
Charney began his career at his alma mater, UCLA, as an instructor in physics and meteorology from 1941 to 1946. In 1946, Charney became a research associate at the University of Chicago under Carl-Gustav Rossby, a Swedish-born American meteorologist whose theories of large-scale air movements helped revolutionize meteorology. From 1947 to 1948, Charney held a National Research Council postgraduate fellowship at the University of Oslo in Norway. During this year, he developed a technique known as the “quasi-geostrophic approximation” for calculating the large-scale motions of planetary-scale waves. Charney's quasi-geostrophic vorticity equations allowed for concise mathematical description of large-scale atmospheric and oceanic circulations, enabling future numerical weather prediction work.
Jule Gregory Charney | Career and legacy
With the introduction of the computer, meteorologists in the United States began numerical experiments to develop quantitative measurement methods to study circulation and climate of the earth. In 1959 and 1960, Möller came to the United States to work with Syukuro Manabe on the numerical determination of radiative fluxes. Moller's second visit to the United States was the evaluation of measurement data from meteorological satellites. He was the only German belonging to the governing body of the Global Atmospheric Research Program. In 1963, he published a paper in the Journal of Geophysical Research which purported to disprove Gilbert Plass's influential 1953 article on the warming influence of industrial carbon dioxide.
Fritz Möller | Climate modeling
Mikhail Ivanovich Budyko (; 20 January 1920 – 10 December 2001) was a Russian climatologist and one of the founders of physical climatology. He pioneered studies on global climate and calculated temperature of Earth considering simple physical model of equilibrium in which the incoming solar radiation absorbed by the Earth's system is balanced by the energy re-radiated to space as thermal energy. Budyko's groundbreaking book, "Heat Balance of the Earth's Surface", published in 1956, transformed climatology from a qualitative into a quantitative physical science. These new physical methods based on heat balance were quickly adopted by climatologists around the world.
Mikhail Budyko | Introduction
In 1954, Carl-Gustav Rossby's group at the Swedish Meteorological and Hydrological Institute used the same model to produce the first operational forecast (i.e., a routine prediction for practical use). Operational numerical weather prediction in the United States began in 1955 under the Joint Numerical Weather Prediction Unit (JNWPU), a joint project by the U.S. Air Force, Navy and Weather Bureau. In 1956, Norman Phillips developed a mathematical model which could realistically depict monthly and seasonal patterns in the troposphere; this became the first successful climate model. Following Phillips' work, several groups began working to create general circulation models. The first general circulation climate model that combined both oceanic and atmospheric processes was developed in the late 1960s at the NOAA Geophysical Fluid Dynamics Laboratory.
Numerical weather prediction | History
As part of his research into weather forecasting, von Neumann founded the "Meteorological Program" in Princeton in 1946, securing funding for his project from the US Navy. Von Neumann and his appointed assistant on this project, Jule Gregory Charney, wrote the world's first climate modelling software, and used it to perform the world's first numerical weather forecasts on the ENIAC computer; von Neumann and his team published the results as "Numerical Integration of the Barotropic Vorticity Equation" in 1950. Together they played a leading role in efforts to integrate sea-air exchanges of energy and moisture into the study of climate.
John von Neumann | Weather systems and global warming
In 1946, Fjørtoft published a treatise on the stability of circular vortices, which gained international recognition. In the same year, he was appointed meteorologist at the Norwegian Meteorological Institute, where he came in contact with Arnt Eliassen. In 1949, Fjørtoft was invited to the Institute for Advanced Study in Princeton, United States. Here, he joined a team composed of the American meteorologists Jule Charney, Philip Thomson, Larry Gates, and applied mathematician John von Neumann, who performed the first successful numerical prediction using the ENIAC electronic computer with the assistance of ENIAC programmer Klara Dan von Neumann. They published their work on numerical weather prediction in the periodical "Tellus" in November 1950.
Ragnar Fjørtoft | Biography
Richardson's interest in meteorology led him to propose a scheme for weather forecasting by solution of differential equations, the method used nowadays, though when he published "Weather Prediction by Numerical Process" in 1922, suitable fast computing was unavailable. He described his ideas thus (his "computers" are human beings): "After so much hard reasoning, may one play with a fantasy? Imagine a large hall like a theatre, except that the circles and galleries go right round through the space usually occupied by the stage. The walls of this chamber are painted to form a map of the globe. The ceiling represents the north polar regions, England is in the gallery, the tropics in the upper circle, Australia on the dress circle and the Antarctic in the pit.
Lewis Fry Richardson | Weather forecasting
Further instruments created at Kew included an improved version of Regnault's aspirated hygrometer that was employed for many years; an early meteorological kite; and the storm clock used to monitor rapid changes in meteorological parameters during extreme events. To observe atmospheric electricity, Ronalds created a sophisticated collecting apparatus with a suite of electrometers; the equipment was later manufactured and sold by London instrument-makers. A dataset of five years' duration was analysed and published by his observatory colleague William Radcliffe Birt. The phenomenon now known as geomagnetically induced current was observed on telegraph lines in 1848 during the first sunspot peak after the network began to take shape.
Francis Ronalds | Meteorological instruments and observations
Svante Arrhenius, in the 19th century, was the first person to quantify global warming as a consequence of a doubling of concentration. In his first paper on the matter, he estimated that global temperature would rise by around if the quantity of was doubled. In later work, he revised this estimate to . Arrhenius used Samuel Pierpont Langley's observations of radiation emitted by the full moon to estimate the amount of radiation that was absorbed by water vapour and . To account for water vapour feedback, he assumed that relative humidity would stay the same under global warming. The first calculation of climate sensitivity using detailed measurements of absorption spectra, and the first to use a computer to numerically integrate the radiative transfer through the atmosphere, was performed by Syukuro Manabe and Richard Wetherald in 1967.
Climate sensitivity | Historical estimates
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 to numerical instability. Starting in the 1950s, numerical forecasts with computers became feasible. The first weather forecasts derived this way used barotropic (single-vertical-level) models, and could successfully predict the large-scale movement of midlatitude Rossby waves, that is, the pattern of atmospheric lows and highs. In 1959, the UK Meteorological Office received its first computer, a Ferranti Mercury.
Meteorology | Numerical weather prediction
In , a working group of climatologists including Raymond S. Bradley, Malcolm K. Hughes, Jean Jouzel, Wibjörn Karlén, Jonathan Overpeck and Tom Wigley proposed a project to improve understanding of natural climatic variations over the last two thousand years so that their effect could be allowed for when evaluating human contributions to climate change. Climate proxy temperature data was needed at seasonal or annual resolution covering a wide geographical area to provide a framework for testing the part climate forcings had played in past variations, look for cycles in climate, and find if debated climatic events such as the Little Ice Age and Medieval Warm Period were global.
Hockey stick graph | IPCC First Assessment Report, 1990, supplement, 1992
Using a hydrostatic variation of Bjerknes's primitive equations, Richardson produced by hand a 6-hour forecast for the state of the atmosphere over two points in central Europe, taking at least six weeks to do so. His forecast calculated that the change in surface pressure would be , an unrealistic value incorrect by two orders of magnitude. The large error was caused by an imbalance in the pressure and wind velocity fields used as the initial conditions in his analysis. The first successful numerical prediction was performed using the ENIAC digital computer in 1950 by a team composed of American meteorologists Jule Charney, Philip Thompson, Larry Gates, and Norwegian meteorologist Ragnar Fjørtoft, applied mathematician John von Neumann, and computer programmer Klara Dan von Neumann.
History of numerical weather prediction | Background
In 1904, Norwegian scientist Vilhelm Bjerknes first argued in his paper "Weather Forecasting as a Problem in Mechanics and Physics" that it should be possible to forecast weather from calculations based upon natural laws. It was not until later in the 20th century that advances in the understanding of atmospheric physics led to the foundation of modern numerical weather prediction. In 1922, Lewis Fry Richardson published "Weather Prediction By Numerical Process," 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.
Meteorology | Numerical weather prediction
In 2020, a study showed that the process of relaxation (adjustment) of localized large-scale pressure anomalies in the lower equatorial troposphere, generates structures strongly resembling the Madden Julian Oscillation (MJO) events, as seen in vorticity, pressure, and moisture fields. Indeed it is demonstrated that baroclinicity and moist convection substantially change the scenario of the quasi-barotropic “dry” adjustment, which was established in the framework of one-layer shallow water model and consists, in the long-wave sector, in the emission of equatorial Rossby waves, with dipolar meridional structure, to the West, and of equatorial Kelvin waves, to the East. If moist convection is strong enough, a dipolar cyclonic structure, which appears in the process of adjustment as a Rossby-wave response to the perturbation, transforms into a coherent modon-like structure in the lower layer, which couples with a baroclinic Kelvin wave through a zone of enhanced convection and produces, at initial stages of the process, a self-sustained slowly eastward-propagating zonally- dissymmetrical quadrupolar vorticity pattern.
Madden–Julian oscillation | Generation of MJO-like structure by geostrophic adjustment in the lower troposphere
Working with students who provided coding expertise as well as original scientific insights (including Chaing Chen, Piotr J. Flatau, Michael D. Moran, Jerome Schmidt, Craig J. Tremback, Gregory Tripoli) he developed one of the first comprehensive mesoscale weather forecast models in the U.S. – the Regional Atmospheric Modeling System (RAMS). This modelling system was subsequently merged with a smaller subset of the code based on the mesoscale model developed independently by Roger A. Pielke for his Ph.D. research related to sea breeze studies and subsequently with his students at the Colorado State University. RAMS has been used as a basis for other weather forecasting systems.
William R. Cotton | Mesoscale modeling
In 1916, to accommodate the growth of steam power, the descriptions were changed to how the sea, not the sails, behaved and extended to land observations. Rotations to scale numbers were standardized only in 1923. George Simpson, CBE (later Sir George Simpson), director of the UK Meteorological Office, was responsible for this and for the addition of the land-based descriptors. The measures were slightly altered some decades later to improve its utility for meteorologists. Nowadays, meteorologists typically express wind speed in kilometers per hour or miles per hour, but Beaufort scale terminology is still used for weather forecasts for shipping and the severe weather warnings given to the public.
Beaufort scale | History
A case study of the Manual of Synoptic Satellite Meteorology featured by the Austrian Meteorological Institute (ZAMG) identified an area of secondary cyclogenesis which brought gusts in excess of 90 km/h to Northern France, Belgium and Southwestern Germany. The system formed in the wake of Lothar, and crossed Europe before the arrival of the later Cyclone Martin. The identification of this secondary area and its frontal systems contrasts with the analysis of the German Weather Service which suggested that solely a 'trough line' crossed Germany.
Cyclone Lothar | Lothar successor
In the 1940s and 1950s, meteorologists at the Bergen School of Meteorology began informally calling some storms that grew over the sea "bombs" because they developed with a great ferocity rarely seen over land. By the 1970s, the terms "explosive cyclogenesis" and even "meteorological bombs" were being used by MIT professor Fred Sanders (building on work from the 1950s by Tor Bergeron), who brought the term into common usage in a 1980 article in the "Monthly Weather Review". In 1980, Sanders and his colleague John Gyakum defined a "bomb" as an extratropical cyclone that deepens by at least (24 sin φ/ sin 60°)mb in 24 hours, where φ represents latitude in degrees.
Explosive cyclogenesis | History
1965). They used the model to simulate for the first time the three-dimensional response of temperature and the hydrologic cycle to increased carbon dioxide(Manabe and Wetherald, 1975). In 1969 Manabe and Bryan published the first simulations of the climate by a coupled ocean-atmosphere models, in which the general circulation model of the atmosphere is combined with that of ocean. Throughout the 1990s early 2000s, Manabe's research group published seminal papers using the coupled atmosphere ocean models to investigate the time-dependent response of climate to changing greenhouse gas concentrations of the atmosphere (Stouffer et al.,1989; Manabe et al., 1991 & 1992).
Syukuro Manabe | Scientific accomplishments
The invention of the thermometer and the barometer during the Scientific Revolution allowed for systematic recordkeeping, that began as early as 1640-1642 in England. Early climate researchers include Edmund Halley, who published a map of the trade winds in 1686 after a voyage to the southern hemisphere. Benjamin Franklin (1706–1790) first mapped the course of the Gulf Stream for use in sending mail from the United States to Europe. Francis Galton (1822–1911) invented the term "anticyclone". Helmut Landsberg (1906–1985) fostered the use of statistical analysis in climatology, which led to its evolution into a physical science. In the early 20th century, climatology was mostly focused on the description of regional climates.
Climatology | History
The April 1960 launch of the first successful weather satellite, TIROS-1, marked the beginning of the age where weather information became available globally.
Meteorology | Instruments and classification scales
With low wind shear and diffluence aloft, the JTWC remarked the system had a fair chance of developing. While the system was organizing, the center crossed the equator to reach about 0.5° S, thus becoming an anticyclonic circulation in the southern hemisphere. This was unusual, as the Coriolis effect is nonexistent along the equator—the Coriolis effect refers to planetary vorticity, which provides the spin in a cyclone. The JTWC later assessed the system as remaining in the northern hemisphere, reaching as far south as 0.7° N, or about 80 km (50 mi) from the equator. After the circulation organized further beneath the convection, the JTWC issued another TCFA at 0300 UTC on November 28.
Cyclone Agni | Meteorological history
In general, westerly wind increases associated with the Madden–Julian oscillation lead to increased tropical cyclogenesis in all basins. As the oscillation propagates from west to east, it leads to an eastward march in tropical cyclogenesis with time during that hemisphere's summer season. There is an inverse relationship between tropical cyclone activity in the western Pacific basin and the north Atlantic basin, however. When one basin is active, the other is normally quiet, and vice versa. The main cause appears to be the phase of the Madden–Julian oscillation, or MJO, which is normally in opposite modes between the two basins at any given time.
Tropical cyclogenesis | Influence of the MJO
In 1956, Norman Phillips developed a mathematical model that realistically depicted monthly and seasonal patterns in the troposphere. This was the first successful climate model. Several groups then began working to create general circulation models. The first general circulation climate model combined oceanic and atmospheric processes and was developed in the late 1960s at the Geophysical Fluid Dynamics Laboratory, a component of the U.S. National Oceanic and Atmospheric Administration. By the early 1980s, the U.S. National Center for Atmospheric Research had developed the Community Atmosphere Model (CAM), which can be run by itself or as the atmospheric component of the Community Climate System Model.
Atmospheric model | Climate modeling
Sir William Napier Shaw (4 March 1854 – 23 March 1945) was a British meteorologist. He introduced the tephigram, a diagram for evaluating convective instability in the atmosphere. He also served as president of the International Meteorological Committee and Royal Meteorological Society.
Napier Shaw | Introduction
Under a cold cyclone, 500 hPa temperatures can fall as low as −30 °C, which can initiate convection even in the driest atmospheres. This also explains why moisture in the mid-levels of the troposphere, roughly at the 500 hPa level, is normally a requirement for development. However, when dry air is found at the same height, temperatures at 500 hPa need to be even colder as dry atmospheres require a greater lapse rate for instability than moist atmospheres. At heights near the tropopause, the 30-year average temperature (as measured in the period encompassing 1961 through 1990) was −77 °C (−105 °F).
Tropical cyclogenesis | Warm waters, instability, and mid-level moisture
Enthusiasts in this formula have created a website that allows visitors to submit data to replicate de Jager's experiment. According to Kendrick Frazier who attended the 1998 Second World Skeptics Congress in Heidelberg, Germany de Jager's "dead-pan" description of how he took measurements throughout his house showing the "absurdities of those who attach great mystical significance to measurements of the Great Pyramid" had the audience "in stitches" Apparently "His home is in an astronomical observatory, a location, he said, 'that may be very close to the cosmos and well receptive to its incredible powers.'”
Cornelis de Jager | Cyclosophy
Until the end of the 19th century, weather prediction was entirely subjective and based on empirical rules, with only limited understanding of the physical mechanisms behind weather processes. In 1901 Cleveland Abbe, founder of the United States Weather Bureau, proposed that the atmosphere is governed by the same principles of thermodynamics and hydrodynamics that were studied in the previous century. In 1904, Vilhelm Bjerknes derived a two-step procedure for model-based weather forecasting. First, a "diagnostic step" is used to process data to generate initial conditions, which are then advanced in time by a "prognostic step" that solves the initial value problem.
History of numerical weather prediction | Background
[1] https://web.archive.org/web/20110716201457/http://meteoriticalsociety.org/simple_template.cfm?code=home_awardees
Jörn Koblitz | References
He is credited as being the first to empirically confirm that cyclone winds blow in a spiral towards the centre of a storm, rather than in a circular motion. This observation was crucial for mariners navigating tropical seas.
Charles Meldrum | Introduction
Since 1984, Colorado State University has been issuing seasonal tropical cyclone forecasts for the north Atlantic basin, with results that are better than climatology. The university has found several statistical relationships for this basin that appear to allow long range prediction of the number of tropical cyclones. Since then, numerous others have followed in the university's steps, with some organizations issuing seasonal forecasts for the northwest Pacific and the Australian region. The predictors are related to regional oscillations in the global climate system: the Walker circulation which is related to the El Niño-Southern Oscillation; the North Atlantic oscillation (NAO); the Arctic oscillation (AO); and the Pacific North American pattern (PNA).
Tropical cyclogenesis | Seasonal forecasts
Grazulis is a Fellow of the American Meteorological Society (AMS) and was on the Fujita Scale Forum of the Fujita Scale Enhancement Project; which developed the Enhanced Fujita Scale to supplant the original Fujita Scale.
Thomas P. Grazulis | Affiliations
Numerical Weather Prediction is a main focus in understanding air–sea interaction, tropical meteorology, atmospheric predictability, and tropospheric/stratospheric processes. The Naval Research Laboratory in Monterey, California, developed a global atmospheric model called Navy Operational Global Atmospheric Prediction System (NOGAPS). NOGAPS is run operationally at Fleet Numerical Meteorology and Oceanography Center for the United States Military. Many other global atmospheric models are run by national meteorological agencies.
Meteorology | Global scale
The history of numerical weather prediction began in the 1920s through the efforts of Lewis Fry Richardson who utilized procedures developed by Vilhelm Bjerknes. It was not until the advent of the computer and computer simulation that computation time was reduced to less than the forecast period itself. ENIAC created the first computer forecasts in 1950, and more powerful computers later increased the size of initial datasets and included more complicated versions of the equations of motion. In 1966, West Germany and the United States began producing operational forecasts based on primitive-equation models, followed by the United Kingdom in 1972 and Australia in 1977.
Atmospheric model | History
In 1963, Edward Lorenz discovered the chaotic nature of the fluid dynamics equations involved in weather forecasting. Extremely small errors in temperature, winds, or other initial inputs given to numerical models will amplify and double every five days, making it impossible for long-range forecasts—those made more than two weeks in advance—to predict the state of the atmosphere with any degree of forecast skill. Furthermore, existing observation networks have poor coverage in some regions (for example, over large bodies of water such as the Pacific Ocean), which introduces uncertainty into the true initial state of the atmosphere. While a set of equations, known as the Liouville equations, exists to determine the initial uncertainty in the model initialization, the equations are too complex to run in real-time, even with the use of supercomputers.
Numerical weather prediction | Ensembles
The short term forecast is as old as weather forecasting itself. During the nineteenth century, the first modern meteorologists were using extrapolation methods for predicting the movement of low pressure systems and anticyclones on surface maps. The researchers subsequently applied the laws of fluid dynamics to the atmosphere and developed the NWP as we know it today. However, the data resolution and parameterization of meteorological primitive equations still leave uncertainty about the small-scale projections, in time and space. The arrival of remote sensing means, such as radar and satellite, and more rapid development of the computer, greatly help to fill that gap.
Nowcasting (meteorology) | Research
For "Rees's Cyclopædia" he contributed articles on meteorology, but the titles are not known. Luke Howard also published the first textbook in meteorology in 1837, "Seven Lectures in Meteorology". In the fifth lecture, Howard included the same classification scheme he proposed in 1802, slightly changing his descriptions. Howard notes again the importance of cloud studies for meteorology in the introduction of his work, claiming clouds to be "the subjects of grave theory and practical research...shewn to be governed, in their production, suspension, and destruction, by... fixed Laws."
Luke Howard | Later meteorological work
This pressure is known as one standard atmosphere. The BIPM's 10th General Conference on Weights and Measures (CGPM) later defined one standard atmosphere to equal precisely 1,013,250 dynes per square centimeter (101.325 kPa). In 1743, the Lyonnais physicist Jean-Pierre Christin, permanent secretary of the "", working independently of Celsius, developed a scale where zero represented the freezing point of water and 100 represented the boiling point of water. On 19 May 1743 he published the design of a mercury thermometer, the "Thermometer of Lyon" built by the craftsman Pierre Casati that used this scale. In 1744, coincident with the death of Anders Celsius, the Swedish botanist Carl Linnaeus (1707–1778) reversed Celsius's scale.
Celsius | History
A preexisting frontal boundary, as defined in surface weather analysis, is required for the development of a mid-latitude cyclone. The cyclonic flow begins around a disturbed section of the stationary front due to an upper level disturbance, such as a short wave or an upper-level trough, near a favorable quadrant of the upper level jet. However, enhanced along-frontal stretching rates in the lower troposphere can suppress the growth of extratropical cyclones.
Cyclogenesis | Precursors for development
The synoptic scale in meteorology (also known as large scale or cyclonic scale) is a horizontal length scale of the order of 1000 kilometers (about 620 miles) or more. This corresponds to a horizontal scale typical of mid-latitude depressions (e.g., extratropical cyclones). Most high- and low-pressure areas seen on weather maps (such as surface weather analyses) are synoptic-scale systems, driven by the location of Rossby waves in their respective hemisphere. Low-pressure areas and their related frontal zones occur on the leading edge of a trough within the Rossby wave pattern, while high-pressure areas form on the back edge of the trough.
Synoptic scale meteorology | Introduction
As Kohler and Reed put it, Korotayev and Turchin have demonstrated that "human population movements and sociopolitical strife play the roles of sometimes endogenous, sometimes exogenous, factors that on small spatial scales may seem inexplicable but which on longer temporal and wider spatial scales may have understandable rhythms".
Andrey Korotayev | Cliodynamics and the study of the Arab Spring
The three succeeded in creating the first geomagnetic polarity time scale. This work made possible the first test, by Frederick Vine and Drummond Matthews, of the seafloor spreading hypothesis. Cox was hired as a professor at Stanford University in 1967. He became Dean of the School of Earth Sciences in 1979 and demonstrated a talent for administration that was widely acknowledged by his colleagues.
Allan V. Cox | Biography
Such upward motions decrease the mass of local atmospheric columns of air, which lower surface pressure.
Cyclogenesis | Modes of development
Related rigorous statistical methods had been developed for tree ring data, with Harold C. Fritts publishing a 1991 study and a 1991 book showing methodology and examples of how to produces maps showing climate developments in North America over time. These methods had been used for regional reconstructions of temperatures, and other aspects such as rainfall. As part of his Phd research, Michael E. Mann worked with seismologist Jeffrey Park on developing statistical techniques for find long term oscillations of natural variability in the instrumental temperature record of global surface temperatures over the last 140 years; showed patterns relating to the El Niño–Southern Oscillation, and found what was later termed the Atlantic multidecadal oscillation.
Hockey stick graph | Climate field reconstruction (CFR) methods; MBH 1998 and 1999
1. Holton, J. R. (2004). An introduction to dynamic meteorology. (4 ed., Vol. 88, pp. 269–276). San Diego, CA: Academic Press. 2. Hoskins, B. J., & Bretherton, F. P. (1972). Atmospheric frontogenesis models: Mathematical formulation and solution. J. Atmos. Sci., 29, 11-13. 3. Martin, J. E. (2006). Mid-latitude atmospheric dynamics. (1 ed., pp. 189–194). England: Wiley.
Frontogenesis | References
Their study was featured in the IPCC Second Assessment Report, and in the United States House Committee on Science its findings were disputed by Pat Michaels. In 1998 Michael E. Mann, Raymond S. Bradley and Malcolm K. Hughes developed new statistical techniques to produce (MBH98), which showed global patterns of annual surface temperature, and included a graph of average hemispheric temperatures back to 1400 with shading emphasising that uncertainties (to two standard error limits) were much greater in earlier centuries. independently produced a CPS reconstruction extending back for a thousand years, and (MBH99) used the MBH98 methodology to extend their study back to 1000.
Wegman Report | Background
As proposed by Edward Lorenz in 1963, it is impossible for long-range forecasts—those made more than two weeks in advance—to predict the state of the atmosphere with any degree of skill, owing to the chaotic nature of the fluid dynamics equations involved. Extremely small errors in temperature, winds, or other initial inputs given to numerical models will amplify and double every five days. Furthermore, existing observation networks have limited spatial and temporal resolution (for example, over large bodies of water such as the Pacific Ocean), which introduces uncertainty into the true initial state of the atmosphere. While a set of equations, known as the Liouville equations, exists to determine the initial uncertainty in the model initialization, the equations are too complex to run in real-time, even with the use of supercomputers.
History of numerical weather prediction | Ensembles
In 1848, William Thomson, 1st Baron Kelvin, asked (and immediately answered) the question With the benefit of the hindsight contained in equation (3), we are able to understand the historical impact of Kelvin's idea on physics. Kelvin suggested that the best temperature scale would describe a constant ability for a unit of temperature in the surroundings to alter the available work from Carnot's engine. From equation (3): Rudolf Clausius recognized the presence of a proportionality constant in Kelvin's analysis and gave it the name entropy in 1865 from the Greek for "transformation" because it describes the quantity of energy lost during transformation from heat to work.
Exergy | A historical and cultural tangent
Weber. In 1867, when he came back from the world exhibition in Paris and brought the first chromic acid cell with him, he also met the astronomer Wilhelm Klinkerfues. Klinkerfues had developed a bifilar-hygrometer which was widely used but did not prove in laymen's hands. After that Lambrecht built a hair hygrometer, "Model Klinkerfues". In 1873, after separation from Klinkerfues, Lambrecht started to build new meteorological instruments such as polymeters, dew point monitors, and aspiration psychrometers. His weather telegraphs, weather columns and combinations of different meteorological instruments were in use at several bigger cities and foreign health resorts before World War I.
Wilhelm Lambrecht | Introduction
For his postdoctoral research Mann joined Bradley and tree ring specialist Malcolm K. Hughes to develop a new statistical approach to reconstruct underlying spatial patterns of temperature variation combining diverse datasets of proxy information covering different periods across the globe, including a rich resource of tree ring networks for some areas and sparser proxies such as lake sediments, ice cores and corals, as well as some historical records. Their global reconstruction was a major breakthrough in evaluation of past climate dynamics, and the first eigenvector-based climate field reconstruction (CFR) incorporating multiple climate proxy data sets of different types and lengths into a high-resolution global reconstruction.
Hockey stick graph | Mann, Bradley and Hughes 1998
It covers the clash of ideas in the 1950s between observationalists including Robert Simpson comparing hurricanes to "heat engines" and theorists and early computer modelers who advocated a mathematical theory Conditional Instability of the Second Kind (CISK). These early disputes set the stage for the current debate. Mooney details William Gray's changing role from groundbreaking theorist to climate change denying anti-theorist set against the background of the increasing public spotlight and urgency to develop a working understanding of storms and global warming in the aftermath of Hurricane Katrina.
Storm World | Overview
Charles Warren Thornthwaite (March 7, 1899 – June 11, 1963) was an American geographer and climatologist. He is best known for devising a climate classification system in 1948 that is still in use worldwide, and also for his detailed water budget computations of potential evapotranspiration. He was Professor of Climatology at Johns Hopkins University, adjunct professor at Drexel University, President of the Commission for Climatology of the World Meteorological Organization, a recipient of the Outstanding Achievement Award of the Association of American Geographers, and the Cullum Geographical Medal from the American Geographical Society.
C. W. Thornthwaite | Introduction
It was not until the 20th century that advances in the understanding of atmospheric physics led to the foundation of modern numerical weather prediction. In 1922, English scientist Lewis Fry Richardson published "Weather Prediction By Numerical Process", after finding notes and derivations he worked on as an ambulance driver in World War I. He described therein how small terms in the prognostic fluid dynamics equations governing atmospheric flow could be neglected, and a finite differencing scheme in time and space could be devised, to allow numerical prediction solutions to be found. Richardson envisioned a large auditorium of thousands of people performing the calculations and passing them to others.
Weather forecasting | Numerical prediction
Paltridge was involved in studies on stratospheric electricity, the effect of the atmosphere on plant growth and the radiation properties of clouds. Paltridge researched topics such as the optimum design of plants and the economics of climate forecasting, and worked on atmospheric radiation and the theoretical basis of climate. Paltridge introduced the subsequently disputed hypothesis that the earth/atmosphere climate system adopts a format that maximises its rate of thermodynamic dissipation, i.e., entropy production. This suggests a governing constraint by a principle of maximum rate of entropy production. According to this principle, prediction of the broad-scale steady-state distribution of cloud, temperature and energy flows in the ocean and atmosphere may be possible when one has sufficient data about the system for that purpose, but does not have fully detailed data about every variable of the system.
Garth Paltridge | Career
In his studies of electricity, he designed sine and tangent galvanometers. Pouillet developed and corrected Joseph Fourier's work on the surface temperature of the earth, developing the first real mathematical treatment of the greenhouse effect. He speculated that water vapour and carbon dioxide might trap infrared radiation in the atmosphere, warming the earth enough to support plant and animal life.
Claude Pouillet | Scientific research
These warm core cyclones tend to form over the oceans between 10 and 30 degrees of the equator.
Cyclogenesis | Tropical cyclones
Models were developed to predict and explain the lack of ice during the warm periods of the Cretaceous and Eocene. Models are developed according to the fundamental principle that they should be kept as simple as possible. Consequently, the first models attempted to explain the lack of ice using solely the different continental configuration. These could not produce an ice-free state without using an increased atmospheric concentration of ; this assumption was checked against the evidence and found to be valid. This introduced a new difficulty: more would produce warmer tropical sea temperatures, and the evidence suggested they were the same or even colder than today's.
Cool tropics paradox | Models
This effect can take up to a century to set in and its strength is dependent on the exact pattern of ocean mixing. It is also subject to positive feedback, as the warming of the eastern Pacific in turn increases tropical cyclone activity; eventually a climate state featuring a permanent El Niño and a weaker El Niño Southern Oscillation can arise. During the mid-Piacenzian where carbon dioxide concentrations were close to present-day levels, Earth was about warmer than present and simulations indicate that tropical cyclones were more intense; the modelled distribution of tropical cyclones however was different from the one reconstructed for other stages of the Pliocene.
Cyclonic Niño | Computer simulations concerning the Pliocene
Qin Jiushao (, ca. 1202–1261), courtesy name Daogu (道古), was a Chinese mathematician, meteorologist, inventor, politician, and writer. He is credited for discovering Horner's method as well as inventing Tianchi basins, a type of rain gauge instrument used to gather meteorological data.
Qin Jiushao | Introduction
The Madden–Julian oscillation (MJO) is the largest element of the intraseasonal (30- to 90-day) variability in the tropical atmosphere. It was discovered in 1971 by Roland Madden and Paul Julian of the American National Center for Atmospheric Research (NCAR). It is a large-scale coupling between atmospheric circulation and tropical deep atmospheric convection. Unlike a standing pattern like the El Niño–Southern Oscillation (ENSO), the Madden–Julian oscillation is a traveling pattern that propagates eastward, at approximately 4 to 8 m/s (14 to 29 km/h, 9 to 18 mph), through the atmosphere above the warm parts of the Indian and Pacific oceans. This overall circulation pattern manifests itself most clearly as anomalous rainfall.
Madden–Julian oscillation | Introduction
This version was featured in the IPCC First Assessment Report of 1990, figure 7.1c on p. 202, as a "Schematic diagram of global temperature variations for the last thousand years."
Hubert Lamb | Medieval warm epoch
The existence of the greenhouse effect, while not named as such, was proposed by Joseph Fourier in 1824. The argument and the evidence were further strengthened by Claude Pouillet in 1827 and 1838. John Tyndall was the first to measure the infrared absorption and emission of various gases and vapours. From 1859 onwards, he showed that the effect was due to a very small proportion of the atmosphere, with the main gases having no effect, and was largely due to water vapour, though small percentages of hydrocarbons and carbon dioxide had a significant effect. The effect was more fully quantified by Svante Arrhenius in 1896, who made the first quantitative prediction of global warming due to a hypothetical doubling of atmospheric carbon dioxide.
Greenhouse effect | History
Beginning with the work of Moritz Cantor and Siegmund Günther, scholars now assign priority to French mathematician Charles de Bovelles based on his description of the cycloid in his "Introductio in geometriam", published in 1503. In this work, Bovelles mistakes the arch traced by a rolling wheel as part of a larger circle with a radius 120% larger than the smaller wheel. Galileo originated the term "cycloid" and was the first to make a serious study of the curve. According to his student Evangelista Torricelli, in 1599 Galileo attempted the quadrature of the cycloid (determining the area under the cycloid) with an unusually empirical approach that involved tracing both the generating circle and the resulting cycloid on sheet metal, cutting them out and weighing them.
Cycloid | History
Simulations using the CESM climate model conducted in 2018 showed a reduced temperature gradient between the East and West Pacific and a deeper thermocline in response to tropical cyclone driven mixing and anomalous eastward sea currents in the Pacific; this is accompanied by a cooling of the areas where mixing is strongest and a warming of the Eastern Pacific. There are also effects on the East Asian monsoon such as a stronger winter monsoon but in the simulations the background climate of the Piacenzian was more significant than the tropical cyclone effects.
Cyclonic Niño | Computer simulations concerning the Pliocene
In 1921, the president of the Commonwealth of Catalonia of that time, Josep Puig i Cadafalch, explained to Eduard Fontserè his concerns about the need for a method to measure the intensity of rainfall. A huge downpour had fallen in Barcelona not long before. Fontserè commissioned Jardí to construct a pluviometer that could record a similar rainfall. Before the end of that year, his device was already working in the Meteorological Service of Catalonia. Patented copies of this pluviometer were mass-produced by two international companies: Richard (Paris) and Casella (London). In June 1927, two pluviometers entered into operation, one in the Department of Meteorology and one in the Fabra Observatory.
Ramón Jardí i Borrás | History
Petar Gburčik (Cyrillic: Петар Гбурчик) (30 October 1931 - 29 October 2006) was a Serbian scientist and a professor of meteorology at the University of Belgrade. He was the author of mathematical models of numerical weather prediction, which were used operationally in the Weather Service of Yugoslavia from 1970 to 1977. In the same period he began modelling the atmospheric diffusion of air pollution and created the first model of the spatial distribution of air pollution. The output of this model was used for the elaboration of the urban plan of Pančevo. For the actual research of the three-dimensional distribution of wind energy (on the territories of Belgrade and Serbia) he applied the integration of classic models with GIS technology.
Petar Gburčik | Introduction
A 2015 simulation of tropical cyclogenesis did not show increased tropical cyclone genesis in the Pliocene, although the simulation did not obtain a decreased East-West Pacific temperature gradient and it did obtain increased tropical cyclone activity in the parts of the Central Pacific most critical for the occurrence of Cyclonic Niño effects. A 2018 simulation implied that adding tropical cyclone mixing induced climate phenomena to simulations of mid-Piacenzian climate can in some aspects improve and in others reduce the match between the modelled climate and the climate reconstructed from paleoclimate data. A 2019 study concluded that tropical cyclone activity in the Western Pacific is correlated to El Niño-associated temperature anomalies months later.
Cyclonic Niño | Subsequent findings
Du Crest believed that the temperature of the Earth was fundamentally fixed, based on the supposition that cellars and mines maintained an equal temperature. He used this "temperature of the terrestrial globe" as one fixed point, measured in a cellar below Paris Observatory, and the temperature of boiling water as a second fixed point. His scale between these points was then divided into one hundred equal degrees.
Jacques-Barthélemy Micheli du Crest | Temperature scale