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104-415: Optical diffusionmeters are devices used in meteorology to find the optical range or the horizontal visibility. They consist of a light source, usually a laser , and a receiver. Both are placed at a 35° angle downward, aimed at a common area. Lateral scattering by the air along the light beam is quantified as an attenuation coefficient . Any departure from the clear air extinction coefficient (e.g. in fog)

208-632: A GPS clock for data logging . Upper air data are of crucial importance for weather forecasting. The most widely used technique is launches of radiosondes . Supplementing the radiosondes a network of aircraft collection is organized 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. The common types of remote sensing are Radar , Lidar , and satellites (or photogrammetry ). Each collects data about

312-479: A CCD matrix to take images at nadir at different view angles as the image moved along the orbit track. A rotating filter wheel and polarizers will produce measurements in eight spectral bands at three different polarization directions (0.435, 0.670, and 0.880 microns at 3 polarization directions and 0.49, 0.52, 0.565, 0.765, and 0.95 microns at no polarization). The POLDER produced images in a swath width of 1,440 × 1,920 km (890 × 1,190 mi) at

416-606: 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

520-498: A Roman geographer, formalized the climatic zone system. In 63–64 AD, Seneca wrote Naturales quaestiones . It was a compilation and synthesis of ancient Greek theories. However, theology was of foremost importance to Seneca, and he believed that phenomena such as lightning were tied to fate. The second book(chapter) of Pliny 's Natural History covers meteorology. He states that more than twenty ancient Greek authors studied meteorology. He did not make any personal contributions, and

624-452: A UV polychromator and photomultiplier (PMT). The TOMS was a single Ebert-Fastie spectrometer with a fixed grating and an array of exit slits. The TOMS step-scanned across the orbital track 51° from the nadir in 3° steps with an FOV of approximately 0.052 rad . At each scan position, the Earth radiance was monitored at six wavelengths (0.304, 0.3125, 0.325, 0.3175, 0.3326, and 0.360 microns) to infer

728-466: 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

832-485: A gale was expected. FitzRoy coined the term "weather forecast" and tried to separate scientific approaches from prophetic ones. Over the next 50 years, many countries established national meteorological services. The India Meteorological Department (1875) was established to follow tropical cyclone and monsoon . The Finnish Meteorological Central Office (1881) was formed from part of Magnetic Observatory of Helsinki University . Japan's Tokyo Meteorological Observatory,

936-511: A ground resolution of 6 × 7 km (3.7 × 4.3 mi). The RIS experiment is provided by the Environment Agency (EA) of Japan on ADEOS. The RIS is a 50 cm (20 in) diameter passive corner cube laser retroreflector designed to provide data to infer the distribution of ozone and other trace gases in the atmosphere. A ground-based laser beam is reflected by the RIS to

1040-621: 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 . 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 . In

1144-473: A legitimate branch of physics. In the 18th century, the invention of the thermometer and barometer allowed for more accurate measurements of temperature and pressure, leading to a better understanding of atmospheric processes. This century also saw the birth of the first meteorological society, the Societas Meteorologica Palatina in 1780. In the 19th century, advances in technology such as

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1248-492: A period up to a year. His system was based on dividing the year by the setting and the rising of the Pleiad, halves into solstices and equinoxes, and the continuity of the weather for those periods. He also divided months into the new moon, fourth day, eighth day and full moon, in likelihood of a change in the weather occurring. The day was divided into sunrise, mid-morning, noon, mid-afternoon and sunset, with corresponding divisions of

1352-950: 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 . 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. Professional stations may also include air quality sensors ( carbon monoxide , carbon dioxide , methane , ozone , dust , and smoke ), ceilometer (cloud ceiling), falling precipitation sensor, flood sensor , lightning sensor , microphone ( explosions , sonic booms , thunder ), pyranometer / pyrheliometer / spectroradiometer (IR/Vis/UV photodiodes ), rain gauge / snow gauge , scintillation counter ( background radiation , fallout , radon ), seismometer ( earthquakes and tremors), transmissometer (visibility), and

1456-458: A swath 1,400 km (870 mi) wide with a ground resolution of 700 m (2,300 ft). OCTS realtime data was transmitted on 465.0 MHz at 20 kbs to local users (e.g. fishing industry ). The POLDER instrument is provided by the Laboratoire d'Études et de Recherches en Télédétection Spatiale (LERTS)/Centre National d'Études Spatiales (CNES) of France for ADEOS. The objective of POLDER

1560-638: A wind speed accuracy of 2 meter/sec and direction accuracy of 20° and a spatial resolution of 25 km (16 mi). NSCAT data was processed to science products directly from telemetry by the NSCAT Data Processing and Instrument Operations (DP&IO). The OCTS was one of the core instruments developed by NASDA for ADEOS. The OCTS is a multispectral radiometer designed to obtain measurements of global ocean color , sea surface temperature , distribution of phytoplankton and oceanic primary productivity, sediment , and suspended material. The OCTS scanned

1664-459: Is a branch of the atmospheric sciences (which include atmospheric chemistry and physics) with a major focus on weather forecasting . The study of meteorology dates back millennia , though significant progress in meteorology did not begin until the 18th century. The 19th century saw modest progress in the field after weather observation networks were formed across broad regions. Prior attempts at prediction of weather depended on historical data. It

1768-466: Is a constellation of eight small satellites utilizing a bistatic approach by analyzing the reflection from the Earth's surface of Global Positioning System (GPS) signals, rather than using an onboard radar transmitter. Scatterometers helped to prove the hypothesis, dating from mid-19th century, of the anisotropic (direction dependent) long distance dispersion by wind to explain the strong floristic affinities between landmasses. A work, published by

1872-648: Is a non-linear inversion procedure based on an accurate knowledge of the GMF (in an empirical or semi-empirical form) that relates the scatterometer backscatter and the vector wind. Retrieval requires an angular diversity scatterometer measurements with the GMF, which is provided by the scatterometer making several backscatter measurements of the same spot on the ocean's surface from different azimuth angles. Scatterometer wind measurements are used for air-sea interaction, climate studies and are particularly useful for monitoring hurricanes . Scatterometer backscatter data are applied to

1976-598: Is also responsible for twilight in Opticae thesaurus ; he estimated that twilight begins when the sun is 19 degrees below the horizon , and also used a geometric determination based on this to estimate the maximum possible height of the Earth's atmosphere as 52,000 passim (about 49 miles, or 79 km). Adelard of Bath was one of the early translators of the classics. He also discussed meteorological topics in his Quaestiones naturales . He thought dense air produced propulsion in

2080-433: Is measured and is inversely proportional to the visibility (the greater the loss, the lower is the visibility). These devices are found in automatic weather stations for general visibility, along airport runways for runway visual range , or along roads for visual conditions. Their main drawback is that the measurement is done over the very small volume of air between the transmitter and the receiver. The visibility reported

2184-487: Is not mandatory to be hired by the media. Each science has its own unique sets of laboratory equipment. In the atmosphere, there are many things or qualities of the atmosphere that can be measured. Rain, which can be observed, or seen anywhere and anytime was one of the first atmospheric qualities measured historically. Also, two other accurately measured qualities are wind and humidity. Neither of these can be seen but can be felt. The devices to measure these three sprang up in

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2288-407: Is therefore only representative of the general conditions around the instrument in generalized conditions ( synoptic fog for instance). This is not always the case (e.g. patchy fog). A radar scatterometer operates by transmitting a pulse of microwave energy towards the Earth 's surface and measuring the reflected energy. A separate measurement of the noise-only power is made and subtracted from

2392-454: The 22° and 46° halos . The ancient Greeks were the first to make theories about the weather. Many natural philosophers studied the weather. However, as meteorological instruments did not exist, the inquiry was largely qualitative, and could only be judged by more general theoretical speculations. Herodotus states that Thales predicted the solar eclipse of 585 BC. He studied Babylonian equinox tables. According to Seneca, he gave

2496-413: The Earth's magnetic field lines. In 1494, Christopher Columbus experienced a tropical cyclone, which led to the first written European account of a hurricane. In 1686, Edmund Halley presented a systematic study of the trade winds and monsoons and identified solar heating as the cause of atmospheric motions. In 1735, an ideal explanation of global circulation through study of the trade winds

2600-628: The Kitab al-Nabat (Book of Plants), in which he deals with the application of meteorology to agriculture during the Arab Agricultural Revolution . He describes the meteorological character of the sky, the planets and constellations , the sun and moon , the lunar phases indicating seasons and rain, the anwa ( heavenly bodies of rain), and atmospheric phenomena such as winds, thunder, lightning, snow, floods, valleys, rivers, lakes. In 1021, Alhazen showed that atmospheric refraction

2704-607: The Smithsonian Institution began to establish an observation network across the United States under the leadership of Joseph Henry . Similar observation networks were established in Europe at this time. The Reverend William Clement Ley was key in understanding of cirrus clouds and early understandings of Jet Streams . Charles Kenneth Mackinnon Douglas , known as 'CKM' Douglas read Ley's papers after his death and carried on

2808-571: The atmospheric sciences . Meteorology and hydrology compose the interdisciplinary field of hydrometeorology . The interactions between Earth's atmosphere and its oceans are part of a coupled ocean-atmosphere system. Meteorology has application in many diverse fields such as the military, energy production, transport, agriculture, and construction. The word meteorology is from the Ancient Greek μετέωρος metéōros ( meteor ) and -λογία -logia ( -(o)logy ), meaning "the study of things high in

2912-417: The heat capacity of gases varies inversely with atomic weight . In 1824, Sadi Carnot analyzed the efficiency of steam engines using caloric theory; he developed the notion of a reversible process and, in postulating that no such thing exists in nature, laid the foundation for the second law of thermodynamics . In 1716, Edmund Halley suggested that aurorae are caused by "magnetic effluvia" moving along

3016-632: The phlogiston theory . In 1777, Antoine Lavoisier discovered oxygen and developed an explanation for combustion. In 1783, in Lavoisier's essay "Reflexions sur le phlogistique," he deprecates the phlogiston theory and proposes a caloric theory . In 1804, John Leslie observed that a matte black surface radiates heat more effectively than a polished surface, suggesting the importance of black-body radiation . In 1808, John Dalton defended caloric theory in A New System of Chemistry and described how it combines with matter, especially gases; he proposed that

3120-516: The Aristotelian method. The work of Theophrastus remained a dominant influence in weather forecasting for nearly 2,000 years. Meteorology continued to be studied and developed over the centuries, but it was not until the Renaissance in the 14th to 17th centuries that significant advancements were made in the field. Scientists such as Galileo and Descartes introduced new methods and ideas, leading to

3224-666: The Earth in the direction perpendicular to the satellite track with a rotating mirror. The OCTS employs a quantum detector and a large radiant cryogenic cooler for the infrared detectors. The rotating mirror was able to tilt 40° forward or backward along the ground track to minimize the effects of Sun glitter from the ocean surface. The OCTS consisted of three infrared channels (8.0-9.0, 10.5-11.5, 11.5-12.5 microns), one middle-IR channel (3.55-3.85 microns), two near-IR channels (0.745-0.785, 0.845-0.885 microns), and six visible channels (0.402-0.422, 0.433-0.453, 0.480-0.50, 0.51-0.53, 0.555-0.575, and 0.655-0.675 microns). The OCTS will provide data in

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3328-516: The Great was the first to propose that each drop of falling rain had the form of a small sphere, and that this form meant that the rainbow was produced by light interacting with each raindrop. Roger Bacon was the first to calculate the angular size of the rainbow. He stated that a rainbow summit cannot appear higher than 42 degrees above the horizon. In the late 13th century and early 14th century, Kamāl al-Dīn al-Fārisī and Theodoric of Freiberg were

3432-524: 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. The April 1960 launch of the first successful weather satellite , TIROS-1 , marked

3536-624: The NASDA ADEOS I satellite, a Ku-band fan-beam system. NASA launched the first scanning scatterometer, known as SeaWinds , on QuikSCAT in 1999. It operated at Ku-band. A second SeaWinds instrument was flown on the NASDA ADEOS-2 in 2002. The Indian Space Research Organisation launched a Ku-band scatterometer on their Oceansat-2 platform in 2009. ESA and EUMETSAT launched the first C-band ASCAT in 2006 onboard Metop -A. The Cyclone Global Navigation Satellite System (CYGNSS), launched in 2016,

3640-647: The Southern Hemisphere. Scatterometers are widely used in metrology for roughness of polished and lapped surfaces in semiconductor and precision machining industries. They provide a fast and non-contact alternative to traditional stylus methods for topography assessment. Scatterometers are compatible with vacuum environments, are not sensitive to vibration, and can be readily integrated with surface processing and other metrology tools. Examples of use on Earth observation satellites or installed instruments, and dates of operation: Meteorology Meteorology

3744-515: The TOMS-2 instrument on the Russian Meteor 3-5 spacecraft launched in 1991. The TOMS instrument was designed to measure total column atmospheric ozone, but also measured global distributions of sulfur dioxide and aerosols due to volcanic eruptions . Ozone concentrations were determined by observing the Earth's albedo at the top of the atmosphere in the ultraviolet (UV) portion of the spectrum using

3848-472: The advancement in weather forecasting and satellite technology, meteorology has become an integral part of everyday life, and is used for many purposes such as aviation, agriculture, and disaster management. In 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

3952-962: The air". Early attempts at predicting weather were often related to prophecy and divining , and were sometimes based on astrological ideas. Ancient religions believed meteorological phenomena to be under the control of the gods. The ability to predict rains and floods based on annual cycles was evidently used by humans at least from the time of agricultural settlement if not earlier. Early approaches to predicting weather were based on astrology and were practiced by priests. The Egyptians had rain-making rituals as early as 3500 BC. Ancient Indian Upanishads contain mentions of clouds and seasons . The Samaveda mentions sacrifices to be performed when certain phenomena were noticed. Varāhamihira 's classical work Brihatsamhita , written about 500 AD, provides evidence of weather observation. Cuneiform inscriptions on Babylonian tablets included associations between thunder and rain. The Chaldeans differentiated

4056-498: The appendix Les Meteores , he applied these principles to meteorology. He discussed terrestrial bodies and vapors which arise from them, proceeding to explain the formation of clouds from drops of water, and winds, clouds then dissolving into rain, hail and snow. He also discussed the effects of light on the rainbow. Descartes hypothesized that all bodies were composed of small particles of different shapes and interwovenness. All of his theories were based on this hypothesis. He explained

4160-412: The atmosphere can be divided into distinct areas that depend on both time and spatial scales. At one extreme of this scale is climatology. In the timescales of hours to days, meteorology separates into micro-, meso-, and synoptic scale meteorology. Respectively, the geospatial size of each of these three scales relates directly with the appropriate timescale. Other subclassifications are used to describe

4264-456: 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. 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 . The study of

Scatterometer - Misplaced Pages Continue

4368-666: The beginning of the age where weather information became available globally. In 1648, Blaise Pascal rediscovered that atmospheric pressure decreases with height, and deduced that there is a vacuum above the atmosphere. In 1738, Daniel Bernoulli published Hydrodynamics , initiating the Kinetic theory of gases and established the basic laws for the theory of gases. In 1761, Joseph Black discovered that ice absorbs heat without changing its temperature when melting. In 1772, Black's student Daniel Rutherford discovered nitrogen , which he called phlogisticated air , and together they developed

4472-460: The best known products of meteorologists for the public, weather presenters on radio and television are not necessarily professional meteorologists. They are most often reporters with little formal meteorological training, using unregulated titles such as weather specialist or weatherman . The American Meteorological Society and National Weather Association issue "Seals of Approval" to weather broadcasters who meet certain requirements but this

4576-401: 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,

4680-444: The chaotic nature of the atmosphere. Mathematical models used to predict the long term weather of the Earth ( climate models ), have been developed that have a resolution today that are as coarse as the older weather prediction models. These climate models are used to investigate long-term climate shifts, such as what effects might be caused by human emission of greenhouse gases . Meteorologists are scientists who study and work in

4784-413: The church and princes. This was supported by scientists like Johannes Muller , Leonard Digges , and Johannes Kepler . However, there were skeptics. In the 14th century, Nicole Oresme believed that weather forecasting was possible, but that the rules for it were unknown at the time. Astrological influence in meteorology persisted until the eighteenth century. Gerolamo Cardano 's De Subilitate (1550)

4888-613: The climate with public health. During the Age of Enlightenment meteorology tried to rationalise traditional weather lore, including astrological meteorology. But there were also attempts to establish a theoretical understanding of weather phenomena. Edmond Halley and George Hadley tried to explain trade winds . They reasoned that the rising mass of heated equator air is replaced by an inflow of cooler air from high latitudes. A flow of warm air at high altitude from equator to poles in turn established an early picture of circulation. Frustration with

4992-422: The clouds and winds extended up to 111 miles, but Posidonius thought that they reached up to five miles, after which the air is clear, liquid and luminous. He closely followed Aristotle's theories. By the end of the second century BC, the center of science shifted from Athens to Alexandria , home to the ancient Library of Alexandria . In the 2nd century AD, Ptolemy 's Almagest dealt with meteorology, because it

5096-416: The concentration of ozone and other trace constituents (such as Nitric acid (HNO 3 ) and H 2 O ) in the stratosphere and to monitor ozone layer dynamics. The ILAS system consisted of two observation packages: One was a 12 cm (4.7 in) telescope containing 44 pyroelectric detectors linearly arrayed for observations in the infrared region of the spectrum (6.0-6.8, 7.3-11.8 microns). The other

5200-491: The description of what is now known as the hydrologic cycle . His work would remain an authority on meteorology for nearly 2,000 years. The book De Mundo (composed before 250 BC or between 350 and 200 BC) noted: After Aristotle, progress in meteorology stalled for a long time. Theophrastus compiled a book on weather forecasting, called the Book of Signs , as well as On Winds . He gave hundreds of signs for weather phenomena for

5304-626: The early study of weather systems. Nineteenth century researchers in meteorology were drawn from military or medical backgrounds, rather than trained as dedicated scientists. In 1854, the United Kingdom government appointed Robert FitzRoy to the new office of Meteorological Statist to the Board of Trade with the task of gathering weather observations at sea. FitzRoy's office became the United Kingdom Meteorological Office in 1854,

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5408-482: 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,

5512-467: The explanation that the cause of the Nile 's annual floods was due to northerly winds hindering its descent by the sea. Anaximander and Anaximenes thought that thunder and lightning was caused by air smashing against the cloud, thus kindling the flame. Early meteorological theories generally considered that there was a fire-like substance in the atmosphere. Anaximander defined wind as a flowing of air, but this

5616-443: The field of meteorology. The American Meteorological Society publishes and continually updates an authoritative electronic Meteorology Glossary . Meteorologists work in government agencies , private consulting and research services, industrial enterprises, utilities, radio and television stations , and in education . In the United States, meteorologists held about 10,000 jobs in 2018. Although weather forecasts and warnings are

5720-652: The first weather observing network, that consisted of meteorological stations in Florence , Cutigliano , Vallombrosa , Bologna , Parma , Milan , Innsbruck , Osnabrück , Paris and Warsaw . The collected data were sent to Florence at regular time intervals. In the 1660s Robert Hooke of the Royal Society of London sponsored networks of weather observers. Hippocrates ' treatise Airs, Waters, and Places had linked weather to disease. Thus early meteorologists attempted to correlate weather patterns with epidemic outbreaks, and

5824-547: The first mission, it ended after less than a year, also following solar panel malfunctions. ADEOS was designed to observe Earth's environmental changes, focusing on global warming , depletion of the ozone layer , and deforestation . On board the satellite are eight instruments developed by NASDA , NASA , and CNES . The Ocean Color and Temperature Scanner (OCTS) is a whisk broom radiometer developed by NASDA. The Advanced Visible and Near Infrared Radiometer (AVNIR), an optoelectronic scanning radiometer with CCD detectors,

5928-400: The first time, a practical method for quickly gathering surface weather observations from a wide area. 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

6032-407: The first to give the correct explanations for the primary rainbow phenomenon. Theoderic went further and also explained the secondary rainbow. By the middle of the sixteenth century, meteorology had developed along two lines: theoretical science based on Meteorologica , and astrological weather forecasting. The pseudoscientific prediction by natural signs became popular and enjoyed protection of

6136-633: The first weather forecasts and temperature predictions. In the 20th and 21st centuries, with the advent of computer models and big data, meteorology has become increasingly dependent on numerical methods and computer simulations. This has greatly improved weather forecasting and climate predictions. Additionally, meteorology has expanded to include other areas such as air quality, atmospheric chemistry, and climatology. The advancement in observational, theoretical and computational technologies has enabled ever more accurate weather predictions and understanding of weather pattern and air pollution. In current time, with

6240-582: The forerunner of the Japan Meteorological Agency , began constructing surface weather maps in 1883. The United States Weather Bureau (1890) was established under the United States Department of Agriculture . The Australian Bureau of Meteorology (1906) was established by a Meteorology Act to unify existing state meteorological services. In 1904, Norwegian scientist Vilhelm Bjerknes first argued in his paper Weather Forecasting as

6344-516: The form of wind. He explained thunder by saying that it was due to ice colliding in clouds, and in Summer it melted. In the thirteenth century, Aristotelian theories reestablished dominance in meteorology. For the next four centuries, meteorological work by and large was mostly commentary . It has been estimated over 156 commentaries on the Meteorologica were written before 1650. Experimental evidence

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6448-549: The ground station and the constituent gases derived from the spectral response. A differential type laser radar system was used to eliminate the attenuating effects of the atmosphere. The TOMS instrument, developed by NASA/ GSFC as part of the Mission to Planet Earth (MTPE), was flown on ADEOS. The TOMS instrument continued the long-term measurement of global total-column ozone begun with the TOMS instrument on Nimbus 7 launched in 1978 and

6552-483: The horizontal distribution of greenhouse effect gases (carbon dioxide , methane , nitrous oxide , etc.) and the vertical distribution of temperature and water vapor . The IMG used an interferometric spectrometer which scanned the spectrum from the middle infrared to thermal infrared (0.3 to 15 microns). A mechanical cryogenic coolant system will be used to regulate the temperature of the quantum detectors. An image motion compensation mirror will be used to compensate for

6656-521: The journal Science in May 2004 with the title "Wind as a Long-Distance Dispersal Vehicle in the Southern Hemisphere", used daily measurements of wind azimuth and speed taken by the SeaWinds scatterometer from 1999 to 2003. They found a stronger correlation of floristic similarities with wind connectivity than with geographic proximities, which supports the idea that wind is a dispersal vehicle for many organisms in

6760-413: The lack of discipline among weather observers, and the poor quality of the instruments, led the early modern nation states to organise large observation networks. Thus, by the end of the 18th century, meteorologists had access to large quantities of reliable weather data. In 1832, an electromagnetic telegraph was created by Baron Schilling . The arrival of the electrical telegraph in 1837 afforded, for

6864-500: The lakes and the Nile. Hippocrates inquired into the effect of weather on health. Eudoxus claimed that bad weather followed four-year periods, according to Pliny. These early observations would form the basis for Aristotle 's Meteorology , written in 350 BC. Aristotle is considered the founder of meteorology. One of the most impressive achievements described in the Meteorology is

6968-437: The late 16th century and first half of the 17th century a range of meteorological instruments were invented – the thermometer , barometer , hydrometer , as well as wind and rain gauges. In the 1650s natural philosophers started using these instruments to systematically record weather observations. Scientific academies established weather diaries and organised observational networks. In 1654, Ferdinando II de Medici established

7072-443: The mechanical, self-emptying, tipping bucket rain gauge. 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

7176-448: The mid-15th century and were respectively the rain gauge , the anemometer, and the hygrometer. Many attempts had been made prior to the 15th century to construct adequate equipment to measure the many atmospheric variables. Many were faulty in some way or were simply not reliable. Even Aristotle noted this in some of his work as the difficulty to measure the air. Sets of surface measurements are important data to meteorologists. They give

7280-413: The near-surface wind vector over the ocean's surface can be determined using a geophysical model function (GMF) which relates wind and backscatter. Over the ocean, the radar backscatter results from scattering from wind-generated capillary-gravity waves, which are generally in equilibrium with the near-surface wind over the ocean. The scattering mechanism is known as Bragg scattering , which occurs from

7384-549: The night, with change being likely at one of these divisions. Applying the divisions and a principle of balance in the yearly weather, he came up with forecasts like that if a lot of rain falls in the winter, the spring is usually dry. Rules based on actions of animals are also present in his work, like that if a dog rolls on the ground, it is a sign of a storm. Shooting stars and the Moon were also considered significant. However, he made no attempt to explain these phenomena, referring only to

7488-507: The opposite effect. Rene Descartes 's Discourse on the Method (1637) typifies the beginning of the scientific revolution in meteorology. His scientific method had four principles: to never accept anything unless one clearly knew it to be true; to divide every difficult problem into small problems to tackle; to proceed from the simple to the complex, always seeking relationships; to be as complete and thorough as possible with no prejudice. In

7592-516: The pattern of atmospheric lows and highs . In 1959, the UK Meteorological Office received its first computer, a Ferranti Mercury . In the 1960s, the chaotic nature of the atmosphere was first observed and mathematically described by Edward Lorenz , founding the field of chaos theory . These advances have led to the current use of ensemble forecasting in most major forecasting centers, to take into account uncertainty arising from

7696-415: The prognostic fluid dynamics equations that govern atmospheric flow could be neglected, and a numerical calculation scheme that could be devised to allow predictions. Richardson envisioned a large auditorium of thousands of people performing the calculations. However, the sheer number of calculations required was too large to complete without electronic computers, and the size of the grid and time steps used in

7800-521: The rain as caused by clouds becoming too large for the air to hold, and that clouds became snow if the air was not warm enough to melt them, or hail if they met colder wind. Like his predecessors, Descartes's method was deductive, as meteorological instruments were not developed and extensively used yet. He introduced the Cartesian coordinate system to meteorology and stressed the importance of mathematics in natural science. His work established meteorology as

7904-584: The satellite orbital motion. Measurements was made in 20 km (12 mi) swaths at 8 km (5.0 mi) resolution. The NSCAT, an active microwave satellite scatterometer, was developed by NASA / JPL as part of the NASA's Earth Probe Mission To Planet Earth (MTPE) program and flown on the Japanese ADEOS. The NSCAT instrument is intended to be a follow-on to the Seasat scatterometer (SASS) flown in 1978. The NSCAT

8008-475: The science of meteorology. Meteorological phenomena are described and quantified by the variables of Earth's atmosphere: temperature, air pressure, water vapour , mass flow , and the variations and interactions of these variables, and how they change over time. Different spatial scales are used to describe and predict weather on local, regional, and global levels. Meteorology, climatology , atmospheric physics , and atmospheric chemistry are sub-disciplines of

8112-442: The scientific revolution in meteorology. Speculation on the cause of the flooding of the Nile ended when Eratosthenes , according to Proclus , stated that it was known that man had gone to the sources of the Nile and observed the rains, although interest in its implications continued. During the era of Roman Greece and Europe, scientific interest in meteorology waned. In the 1st century BC, most natural philosophers claimed that

8216-440: The seasons. He believed that fire and water opposed each other in the atmosphere, and when fire gained the upper hand, the result was summer, and when water did, it was winter. Democritus also wrote about the flooding of the Nile. He said that during the summer solstice, snow in northern parts of the world melted. This would cause vapors to form clouds, which would cause storms when driven to the Nile by northerly winds, thus filling

8320-578: The second oldest national meteorological service in the world (the Central Institution for Meteorology and Geodynamics (ZAMG) in Austria was founded in 1851 and is the oldest weather service in the world). The first daily weather forecasts made by FitzRoy's Office were published in The Times newspaper in 1860. The following year a system was introduced of hoisting storm warning cones at principal ports when

8424-527: The signal+noise measurement to determine the backscatter signal power. Sigma-0 (σ⁰) is computed from the signal power measurement using the distributed target radar equation. Scatterometer instruments are very precisely calibrated in order to make accurate backscatter measurements. The primary application of spaceborne scatterometry has been measurements of near-surface winds over the ocean . Such instruments are known as wind scatterometers. By combining sigma-0 measurements from different azimuth angles,

8528-578: The study of vegetation , soil moisture , polar ice , tracking Antarctic icebergs and global change . Scatterometer measurements have been used to measure winds over sand and snow dunes from space. Non-terrestrial applications include study of Solar System moons using space probes. This is especially the case with the NASA/ESA Cassini mission to Saturn and its moons. Several generations of wind scatterometers have been flown in space by NASA , ESA , and NASDA . The first operational wind scatterometer

8632-579: The surface was used to derive the backscattered radiation as a function of both wind speed and direction and to determine the wind vector. The NSCAT consisted of three major subsystems: the Radio Frequency Subsystem (RFS), the antenna subsystem, and the Digital Data Subsystem (DSS). Transmitted pulses at 13.995 GHz are generated by the RFS to each antenna beam. A low-noise amplifier of 3 dB

8736-427: The telegraph and photography led to the creation of weather observing networks and the ability to track storms. Additionally, scientists began to use mathematical models to make predictions about the weather. The 20th century saw the development of radar and satellite technology, which greatly improved the ability to observe and track weather systems. In addition, meteorologists and atmospheric scientists started to create

8840-422: The total ozone amount. The TOMS completed a cross scan in eight seconds, with one second for retrace, to record 37 scenes per scan. At each scene, a chopper sequentially sampled all six wavelengths four times. The TOMS used a PMT and a separate mercury-argon lamp for wavelength calibration and a depolarizer. On 28 August 1996, the satellite adjusted its attitude to control its orbit. As a result of this maneuver,

8944-456: The unique, local, or broad effects within those subclasses. ADEOS I ADEOS I ( Advanced Earth Observing Satellite 1 ) was an Earth observation satellite launched by NASDA in 1996. The mission's Japanese name, Midori means "green". The mission ended in July 1997 after the satellite sustained structural damage to the solar panel . Its successor, ADEOS II , was launched in 2002. Like

9048-572: The value of his work is in preserving earlier speculation, much like Seneca's work. From 400 to 1100, scientific learning in Europe was preserved by the clergy. Isidore of Seville devoted a considerable attention to meteorology in Etymologiae , De ordine creaturum and De natura rerum . Bede the Venerable was the first Englishman to write about the weather in De Natura Rerum in 703. The work

9152-405: The waves that are in resonance with the microwaves. The backscattered power depends on the wind speed and direction. Viewed from different azimuth angles, the observed backscatter from these waves varies. These variations can be exploited to estimate the sea surface wind, i.e. its speed and direction. This estimate process is sometimes termed ' wind retrieval' or ' model function inversion' . This

9256-480: Was a multispectral radiometer for observing the Earth in the visible and near-IR wavelengths at high spatial resolution. The AVNIR employs a Schmidt optical system and an electronic scanning CCD silicon array. The AVNIR consisted of three visible channels (0.40-0.50, 0.52-0.62, 0.62-0.72 microns) and one near-IR channel (0.82-0.92 micron). In addition, the AVNIR also had a panchromatic channel at 0.52-0.72 micron. The AVNIR

9360-470: Was a 3 cm (1.2 in) telescope consisting of a photodiode array for observations in the visible region (0.753-0.784 microns). Sunrise and sunset observations was made at 2 km (1.2 mi) resolution over the 10–60 km (6.2–37.3 mi) vertical range. The IMG instrument was provided by the Ministry of International Trade and Industry (MITI) of Japan for ADEOS. The IMG is designed to monitor

9464-417: Was a summary of then extant classical sources. However, Aristotle's works were largely lost until the twelfth century, including Meteorologica . Isidore and Bede were scientifically minded, but they adhered to the letter of Scripture . Islamic civilization translated many ancient works into Arabic which were transmitted and translated in western Europe to Latin. In the 9th century, Al-Dinawari wrote

9568-466: Was able to tilt 40° on either side of the ground track producing a 5.7° field of view and an 60 km (37 mi) swath width . The ground resolution was 16 m (52 ft) for the multispectral bands and 8 m (26 ft) for the panchromatic band. The ILAS instrument was provided by the Environment Agency of Japan for ADEOS mission. The ILAS was designed to measure the variability of

9672-502: Was also launched on ADEOS II . The Improved Limb Atmospheric Spectrometer (ILAS) was developed by NASDA and the Environment Agency of Japan , and used grating spectrometers to measure the properties of trace gases using solar occultation . The Retroreflector in Space (RIS) and Interferometric Monitor for Greenhouse Gases (IMG) were both developed by Japan, and studied atmospheric trace gases and greenhouse gases respectively. The AVNIR

9776-481: Was also produced by NASDA. The NASA Scatterometer (NSCAT), developed with the Jet Propulsion Laboratory (JPL), used fan-beam Doppler signals to measure wind speeds over bodies of water. The Total Ozone Mapping Spectrometer (TOMS) was built by CNES to study changes to Earth's ozone layer . The Polarization and Directionality of the Earth's Reflectance (POLDER) device was also developed by CNES, and

9880-468: Was considered a subset of astronomy. He gave several astrological weather predictions. He constructed a map of the world divided into climatic zones by their illumination, in which the length of the Summer solstice increased by half an hour per zone between the equator and the Arctic. Ptolemy wrote on the atmospheric refraction of light in the context of astronomical observations. In 25 AD, Pomponius Mela ,

9984-435: Was designed to measure the ocean surface wind velocity and provided data on air-sea interactions, calculations for large-scale fluxes between atmosphere and ocean, air-sea coupling and interannual variability of the Earth's climate. The NSCAT was a 13.995 GHz ( Ku-band ) active microwave radar that transmitted continuous pulses to the ocean surface and received backscattered radiation from the Earth. The radar cross section of

10088-714: Was known as the Seasat Scatterometer (SASS) and was launched in 1978. It was a fan-beam system operating at Ku-band (14 GHz). In 1991 ESA launched the European Remote-Sensing Satellite ERS-1 Advanced Microwave Instrument (AMI) scatterometer, followed by the ERS-2 AMI scatterometer in 1995. Both AMI fan-beam systems operated at C-band (5.6 GHz). In 1996 NASA launched the NASA Scatterometer (NSCAT), on board

10192-428: Was less important than appeal to the classics and authority in medieval thought. In the thirteenth century, Roger Bacon advocated experimentation and the mathematical approach. In his Opus majus , he followed Aristotle's theory on the atmosphere being composed of water, air, and fire, supplemented by optics and geometric proofs. He noted that Ptolemy's climatic zones had to be adjusted for topography . St. Albert

10296-406: Was not generally accepted for centuries. A theory to explain summer hail was first proposed by Anaxagoras . He observed that air temperature decreased with increasing height and that clouds contain moisture. He also noted that heat caused objects to rise, and therefore the heat on a summer day would drive clouds to an altitude where the moisture would freeze. Empedocles theorized on the change of

10400-589: Was not until after the elucidation of the laws of physics, and more particularly in the latter half of the 20th century, the development of the computer (allowing for the automated solution of a great many modelling equations) that significant breakthroughs in weather forecasting were achieved. An important branch of weather forecasting is marine weather forecasting as it relates to maritime and coastal safety, in which weather effects also include atmospheric interactions with large bodies of water. Meteorological phenomena are observable weather events that are explained by

10504-399: Was the first work to challenge fundamental aspects of Aristotelian theory. Cardano maintained that there were only three basic elements- earth, air, and water. He discounted fire because it needed material to spread and produced nothing. Cardano thought there were two kinds of air: free air and enclosed air. The former destroyed inanimate things and preserved animate things, while the latter had

10608-404: Was to observe the Earth's radiation budget under different view angles and polarizations to study the optical and physical properties of clouds and the interactions of solar radiation with the Earth atmosphere system. POLDER was equipped with a wide angle objective taking two dimensional images at various wavelengths in the visible and near-infrared at different polarizations. The instrument will use

10712-537: Was used to amplify the return echo. The antenna subsystem consisted of 6 identical, dual-polarization fan beam antennas, approximately 3 m (9.8 ft) long. The six antennas were calibrated to 0.25 dB prior to launch. The NSCAT was the first spaceborne scatterometer to employ on-board digital processing of the Doppler-shifted signal. The NSCAT measured two swaths, each 600 km (370 mi) wide at nadir and radar cross sections in three azimuth angles for

10816-531: Was written by George Hadley . In 1743, when Benjamin Franklin was prevented from seeing a lunar eclipse by a hurricane , he decided that cyclones move in a contrary manner to the winds at their periphery. Understanding the kinematics of how exactly the rotation of the Earth affects airflow was partial at first. Gaspard-Gustave Coriolis published a paper in 1835 on the energy yield of machines with rotating parts, such as waterwheels. In 1856, William Ferrel proposed

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