history of meteorology and weather instrumentPresentation Transcript
History of meteorologyandinventions of weather instruments
is the scientific study of the atmosphere that focuses on weather processes and forecasting. There is also broad discussion of atmospheric physics and atmospheric chemistry, including such topics as air pollution, tropical cyclones, mid latitude weather. Meteorology is also the interdisciplinary scientific study of the atmosphere that focuses on weather processes and short term forecasting (in contrast with climatology). Studies in the field stretch back millennia, though significant progress in meteorology did not occur until the eighteenth century. The nineteenth century saw breakthroughs occur after observing networks developed across several countries. Breakthroughs in weather forecasting were achieved in the latter half of the twentieth century, after the development of the computer.
are scientists who study meteorology. Meteorologists work in government agencies, private consulting and research services, industrial enterprises, utilities, radio and television stations, and in education.
Visual atmospheric phenomena
In 1021, Ibn al-Haytham (Alhazen) wrote on the atmospheric refraction of light. He showed that the twilight is due to atmospheric refraction and only begins when the Sun is 19 degrees below the horizon, and uses a complex geometric demonstration to measure the height of the Earth's atmosphereas 52,000 passuum (49 miles (79 km),which is very close to the modern measurement of 50 miles (80 km). He also realized that the atmosphere also reflects light, from his observations of the sky brightening even before the Sunrises.
In 1648, Blaise Pascal rediscovers that atmospheric pressure decreases with height, and deduces that there is a vacuum above the atmosphere.In 1738, Daniel Bernoulli publishes Hydrodynamics, initiating the kinetic theory of gases and established the basic laws for the theory of gases. In 1761, Joseph Black discovers that ice absorbs heat without changing its temperature when melting. In 1772, Black's student Daniel Rutherford discovers nitrogen, which he calls phlogisticated air, and together they developed the phlogiston theory. In 1777, Antoine Lavoisier discovers oxygen and develops an explanation for combustion. In 1783, in Lavoisier's book Reflexions sur le phlogistique, he deprecates the phlogiston theory and proposes a caloric theory. In 1804, Sir John Leslie observes that a matte black surface radiates heat more effectively than a polished surface, suggesting the importance of black body radiation..
Cyclones and air flow
In 1494, Christopher Columbus experiences a tropical cyclone, leads to the first written European account of a hurricane. In 1686, Edmund Halley presents a systematic study of the trade winds and monsoons and identifies solar heating as the cause of atmospheric motions. In 1735, an ideal explanation of global circulation through study of the Trade winds was written by George Hadley. In 1743, when Benjamin Franklin is prevented from seeing a lunar eclipse by a hurricane, he decides 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 the existence of a circulation cell in the mid-latitudes with air being deflected by the Coriolis force to create the prevailing westerly winds. Late in the 19th century the full extent of the large scale interaction of pressure gradient force and deflecting force that in the end causes air masses to move alongisobars was understood. By 1912, this deflecting force was named the Coriolis effect. Just after World War II, 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, introducing 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 the mechanism by which rain forms) and Jacob Bjerknes.
Observation networks and weather forecasting
In 1654, Ferdinando II de Medici establishes the first weather observing network, that consisted of meteorological stations in Florence, Cutigliano, Vallombrosa, Bologna, Parma,Milan,Innsbruck,Osnabrück, Paris and Warsaw. Collected data was centrally sent to Florence at regular time intervals. In 1832, an electromagnetic telegraph was created by Baron Schilling. The arrival of the electrical telegraphin 1837 afforded, for the first time, a practical method for quickly gathering surface weather observations froma 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 the Smithsonian Institutionbegan to establish an observation network across the United States under the leadership of Joseph Henry.
is the study of atmospheric phenomena that has horizontal scales ranging from micro-scale limits to synoptic scale limits and a vertical scale that starts at the Earth's surface and includes the atmospheric boundary layer, troposphere, tropopause, and the lower section of thestratosphere. Meso-scale timescales last from less than a day to the lifetime of the event, which in some cases can be weeks.
meteorology can be divided into distinct areas of emphasis depending on the temporal scope and spatial scope of interest. At one extreme of this scale is climatology. In the timescales of hours to days, meteorology separates into micro-, meso-, and synoptic scale meteorology. Respectively, the geospatial size of each of these three scales relates directly with the appropriate timescale. Other sub-classifications are available based on the need by or by the unique, local or broad effects that are studied within that sub-class.
micro-scale meteorology is the study of atmospheric phenomena of about 1 km or less. Individual thunderstorms, clouds, and local turbulence caused by buildings and other obstacles, such as individual hills fall within this category.
is generally large area dynamics referred to in horizontal coordinates and with respect to time. The phenomena typically described by synoptic meteorologyinclude events like extratropical cyclones, baroclinic troughs and ridges, frontal zones, and to some extent jet streams. All of these are typically given on weather mapsfor a specific time. The minimum horizontal scale of synoptic phenomena is limited to the spacing between surface observation stations.
is study of weather patterns related to the transport of heat from the tropics to the poles. Also, very large scale oscillations are of importance. Global scale pushes the thresholds of the perception of meteorology into climatology. The traditional definition of climate is pushed in to larger timescales with the further understanding of how the global oscillations cause both climate and weather disturbances in the synoptic and meso-scale timescales.
Invention of Weather Instruments
measure temperature, by using materials that change in some way when they are heated or cooled. In a mercury or alcohol thermometer the liquid expands as it is heated and contracts when it is cooled, so the length of the liquid column is longer or shorter depending on the temperature. Modern thermometersare calibrated in standard temperature units such as Fahrenheit or Celsius.
are instruments used for measuring the pressure of the air in the atmosphere. They weren't invented until the 1840s—years after Franklin's time. High or rising pressure means that clear, sunny weather is expected, while falling or low pressure is a sign of rain or an approaching storm. As air pressure increases, it pushes down on a metal diaphragm, which in turn causes the indicating needle to move. This aneroid barometer was made in Germany and sits on an octagonal wooden base.
was invented in the fourth month of 1441. The invention of the rain gauge in Korea came two hundred years before inventor Christopher Wren created a rain gauge (tipping bucket rain gauge circa 1662) in Europe. One source has is that the son of King Sejong the Great, who reigned the Choson Dynasty from 1418 to 145, invented the first rain gauge. King Sejong sought ways to improve agricultural technology to provide his subjects with adequate food and clothing.
In improving agricultural technology, Sejong contributed to the sciences of astronomy and meteorology (weather). He invented a calendar for the Korean people and ordered the development of accurate clocks. Droughts plagued the kingdom and King Sejong directed every village to measure the amount of rainfall.
is an instrument used to measure the moisture content or the humidity of air or any gas. The best known type of hygrometer is the "dry and wet-bulb psychrometer", best described as two mercury thermometers, one with a wetted base, one with a dry base. The water from the wet base evaporates and absorbs heat causing the thermometer reading to drop. Using a calculation table, the reading from the dry thermometer and the reading drop from the wet thermometer are used to determine the relative humidity.
Evangelista Torricelli is credited with inventing the barometer in 1643 to measure air pressure, but both Giovanni Battista Baliani in 1630 and René Descartes in 1631 had postulated a version of the barometer even earlier than that. GasperoBerti, who had heard from Galileo about the design written down by Baliani, attempted to experiment with water in a vacuum between 1639 and 1641 to explain why pumps would not draw water above a certain height. Torricelli, however, approached it from a different angle and recognized that air had weight; he also recognized that mercury in a barometer was a suitable replacement for water. Years later, Blaise Pascal and Florin Périer refined the design.