Nat.sci - wisley rait
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Published on: Mar 3, 2016
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In 350 BC, Aristotle wrote Meteorology. Aristotleis considered the founder of meteorology. One ofthe most impressive achievements described inthe Meteorology is the description of what is nowknown as the hydrologic cycle. The Greekscientist Theophrastus compiled a book onweather forecasting, called the Book of Signs.The work of Theophrastus remained a dominantinfluence in the study of weather and in weatherforecasting for nearly 2,000 years.
In 25 AD, Pomponius Mela, a geographer for the RomanEmpire, formalized the climatic zone system. Around the9th century, Al-Dinawari, a Kurdish naturalist, writes theKitab al-Nabat (Book of Plants), in which he deals with theapplication of meteorology to agriculture during theMuslim Agricultural Revolution. He describes themeteorological character of the sky, the planets andconstellations, the sun and moon, the lunar phasesindicating seasons and rain, the anwa (heavenly bodies ofrain), and atmospheric phenomena such as winds,thunder, lightning, snow, floods, valleys, rivers, lakes,wells and other sources of water.
In 1021, Ibn al-Haytham (Alhazen) wrote on the atmosphericrefraction of light. He showed that the twilight is due to atmosphericrefraction and only begins when the Sun is 19 degrees below thehorizon, and uses a complex geometric demonstration to measurethe height of the Earths atmosphere as 52,000 passuum (49 miles(79 km)), which is very close to the modern measurement of50 miles (80 km). He also realized that the atmosphere also reflectslight, from his observations of the sky brightening even before theSun rises. St. Albert the Great was the first to propose that eachdrop of falling rain had the form of a small sphere, and that this formmeant that the rainbow was produced by light interacting with eachraindrop. Roger Bacon was the first to calculate the angular size ofthe rainbow. He stated that the rainbow summit can not appearhigher than 42 degrees above the horizon.
In the late 13th century and early 14th century,Theodoric of Freiberg and Kamāl al-Dīn al-Fārisī continued the work of Ibn al-Haytham,and they were the first to give the correctexplanations for the primary rainbowphenomenon. Theoderic went further and alsoexplained the secondary rainbow. In 1716,Edmund Halley suggests that aurorae arecaused by "magnetic effluvia" moving along theEarths magnetic field lines.
In 1441, King Sejongs son, Prince Munjong, invented the firststandardized rain gauge. These were sent throughout the JoseonDynasty of Korea as an official tool to assess land taxes based upon afarmers potential harvest. In 1450, Leone Battista Alberti developed aswinging-plate anemometer, and is known as the first anemometer. In1607, Galileo Galilei constructs a thermoscope. In 1611, JohannesKepler writes the first scientific treatise on snow crystals: "Strena Seu deNive Sexangula (A New Years Gift of Hexagonal Snow)". In 1643,Evangelista Torricelli invents the mercury barometer. In 1662, SirChristopher Wren invented the mechanical, self-emptying, tipping bucketrain gauge. In 1714, Gabriel Fahrenheit creates a reliable scale formeasuring temperature with a mercury-type thermometer. In 1742,Anders Celsius, a Swedish astronomer, proposed the centigradetemperature scale, the predecessor of the current Celsius scale.
In 1783, the first hair hygrometer is demonstrated byHorace-Bénédict de Saussure. In 1802-1803, Luke Howardwrites On the Modification of Clouds in which he assignscloud types Latin names. In 1806, Francis Beaufortintroduced his system for classifying wind speeds. Near theend of the 19th century the first cloud atlases werepublished, including the International Cloud Atlas, whichhas remained in print ever since. The April 1960 launch ofthe first successful weather satellite, TIROS-1, marked thebeginning of the age where weather information becameavailable globally.
In 1648, Blaise Pascal rediscovers that atmospheric pressuredecreases with height, and deduces that there is a vacuumabove the atmosphere. In 1738, Daniel Bernoulli publishesHydrodynamics, initiating the kinetic theory of gases andestablished the basic laws for the theory of gases. In 1761,Joseph Black discovers that ice absorbs heat without changingits temperature when melting. In 1772, Blacks student DanielRutherford discovers nitrogen, which he calls phlogisticated air,and together they developed the phlogiston theory. In 1777,Antoine Lavoisier discovers oxygen and develops anexplanation for combustion. In 1783, in Lavoisiers bookReflexions sur le phlogistique, he deprecates the phlogistontheory and proposes a caloric theory.
In 1804, Sir John Leslie observes that a matte black surfaceradiates heat more effectively than a polished surface,suggesting the importance of black body radiation. In 1808,John Dalton defends caloric theory in A New System ofChemistry and describes how it combines with matter,especially gases; he proposes that the heat capacity of gasesvaries inversely with atomic weight. In 1824, Sadi Carnotanalyzes the efficiency of steam engines using caloric theory;he develops the notion of a reversible process and, inpostulating that no such thing exists in nature, lays thefoundation for the second law of thermodynamics.
In 1494, Christopher Columbus experiences a tropical cyclone,leads to the first written European account of a hurricane. In1686, Edmund Halley presents a systematic study of the tradewinds and monsoons and identifies solar heating as the cause ofatmospheric motions. In 1735, an ideal explanation of globalcirculation through study of the Trade winds was written byGeorge Hadley.[ In 1743, when Benjamin Franklin is preventedfrom seeing a lunar eclipse by a hurricane, he decides thatcyclones move in a contrary manner to the winds at theirperiphery. Understanding the kinematics of how exactly therotation of the Earth affects airflow was partial at first. Gaspard-Gustave Coriolis published a paper in 1835 on the energy yieldof machines with rotating parts, such as waterwheels. In 1856,William Ferrel proposed the existence of a circulation cell in themid-latitudes with air being deflected by the Coriolis force tocreate the prevailing westerly winds.
In 1654, Ferdinando II de Medici establishes the first weather observingnetwork, that consisted of meteorological stations in Florence,Cutigliano, Vallombrosa, Bologna, Parma, Milan, Innsbruck, Osnabrück,Paris and Warsaw. Collected data was centrally sent to Florence atregular time intervals. In 1832, an electromagnetic telegraph wascreated by Baron Schilling. The arrival of the electrical telegraph in1837 afforded, for the first time, a practical method for quickly gatheringsurface weather observations from a wide area. This data could beused to produce maps of the state of the atmosphere for a region nearthe Earths surface and to study how these states evolved through time.To make frequent weather forecasts based on these data required areliable network of observations, but it was not until 1849 that theSmithsonian Institution began to establish an observation networkacross the United States under the leadership of Joseph Henry.
Europe at this time. In 1854, the United Kingdom governmentappointed Robert FitzRoy to the new office of MeteorologicalStatist to the Board of Trade with the role of gathering weatherobservations at sea. FitzRoys office became the UnitedKingdom Meteorological Office in 1854, the first nationalmeteorological service in the world. The first daily weatherforecasts made by FitzRoys Office were published in TheTimes newspaper in 1860. The following year a system wasintroduced of hoisting storm warning cones at principal portswhen a gale was expected.
In 1904, Norwegian scientist Vilhelm Bjerknes first argued in his paper WeatherForecasting as a Problem in Mechanics and Physics that it should be possibleto forecast weather from calculations based upon natural laws.It was not until later in the 20th century that advances in the understanding ofatmospheric physics led to the foundation of modern numerical weatherprediction. In 1922, Lewis Fry Richardson published "Weather Prediction ByNumerical Process", after finding notes and derivations he worked on as anambulance driver in World War I. He described therein how small terms in theprognostic fluid dynamics equations governing atmospheric flow could beneglected, and a finite differencing scheme in time and space could bedevised, to allow numerical prediction solutions to be found. Richardsonenvisioned a large auditorium of thousands of people performing thecalculations and passing them to others. However, the sheer number ofcalculations required was too large to be completed without the use ofcomputers, and the size of the grid and time steps led to unrealistic results indeepening systems. It was later found, through numerical analysis, that thiswas due to numerical instability.
Starting in the 1950s, numerical forecasts with computersbecame feasible. The first weather forecasts derived this wayused barotropic (that means, single-vertical-level) models, andcould successfully predict the large-scale movement ofmidlatitude Rossby waves, that is, the pattern of atmosphericlows and highs..In the 1960s, the chaotic nature of the atmosphere was firstobserved and mathematically described by Edward Lorenz,founding the field of chaos theory. These advances have led tothe current use of ensemble forecasting in most majorforecasting centers, to take into account uncertainty arising fromthe chaotic nature of the atmosphere. Climate models have beendeveloped that feature a resolution comparable to older weatherprediction models. These climate models are used to investigatelong-term climate shifts, such as what effects might be caused byhuman emission of greenhouse gases.
Measuring theWeatherIn the early days of the Weather Bureau numerousclever mechanical devices were invented to measureand record any and every meteorological (weather)parameter conceivable: ombroscope or rainfallrecorder, mechanical anemometer or wind speedindicator, remote readout wind vane, pole starrecorder.
•Wind velocity or speed is measured by a cupanemometer, an instrument with three or four smallhollow metal hemispheres set so that they catch thewind and revolve about a vertical rod. An electricaldevice records the revolutions of the cups andcalculates the wind velocity. The word anemometercomes from the Greek word for wind, "anemos."
•Barometer - Pronunciation: [b u rom u t u r] - abarometer is an instrument for measuringatmospheric pressure. The barometer wasinvented by Evangelista Torricelli in 1643.
•A hygrometer is an instrument used to measurethe moisture content or the humidity of air or anygas.
•A rain gauge measures how much rain has fallen.
•Thermometers measure temperature by usingmaterials that change in some way when they areheated or cooled. The first thermometers werecalled thermoscopes, and while several inventorsinvented a version of the thermoscope at thesame time, Italian inventor Santorio Santorio wasthe first inventor to put a numerical scale on theinstrument. In 1724, Gabriel Fahrenheit inventedthe first mercury thermometer.