History of Meteorology Three General Historical Periods Ancient Times: 600 B.C. to 1500 A.D. 1500...
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Transcript of History of Meteorology Three General Historical Periods Ancient Times: 600 B.C. to 1500 A.D. 1500...
History of MeteorologyHistory of Meteorology
Three General Historical Three General Historical PeriodsPeriods
Ancient Times: 600 B.C. to 1500 A.D.
1500 A.D. to 1800 A.D.1800 A.D. to Modern Times
MeteorologyMeteorology
Word was invented by the Greeks over 200 years ago (Aristotle)
meta = beyondeora = suspensionMeteoros = high in the airAristotle meant atmospheric elements such as
rain, snow, hail, wind, thunder or lightning, and also earthquakes, comets and the Milky Way
Don’t confuse this with the astronomical terms for meteors which are extraterrestrial objects
AtmosphereAtmosphere
Also comes from the Greek
Atmos = Vapor
The atmosphere is a region of vapor
Ancient Period 600 B.C. to Ancient Period 600 B.C. to 1500 A.D.1500 A.D.
Meteorology part of general science
Based on pseudo-scientific speculations
Scientific discoveries from all parts of the world: Babylonians, Sumerians, Chinese, Hindus, Egyptians, Greeks, Romans, and Arabs
Ancient PeriodAncient Period
Babylonians – foundations of early mathematics and the four cardinal directions
Egyptians – defined weights and measures, invented ingenious water-clocks, and introduced the 365 day year
Chinese – invented the compass and made astronomical as well as meteorological observations
Ancient PeriodAncient Period
Greeks – developed geometry, logic and philosophy – also performed meteorological observations and created physical theories
Hippocrates: study of climate
Aristotle: Meteorologica
Theophrastus: meteorological treatise
Ancient PeriodAncient Period
Romans – didn’t contribute much except in the field of organization, law, medicine, agriculture and the building of aqueducts
Seneca – interested in meteorologyMiddle Ages – stagnation in the arts and
sciences – burned the library in AlexandriaArabs – mathematics, optics and astronomy
and the number system
A Water-ClockA Water-Clock
1500 – 1800 1500 – 1800
Age of Genius and the Age of ReasonCopernicus – heliocentric theory of the
universeFoundations of modern meteorology laid in
Europe with the invention of meteorological instruments and the introduction of meteorological observations
1500 – 18001500 – 1800
Galileo – invented the gas thermometer Toricelli – invented the mercury barometer Pascal and Descartes – showed pressure decreases
with increasing altitude Robert Hooke – swing-type anemometer for wind
speed Boyle – formulated the gas laws Newton – the laws of mechanics Euler – equations of fluid motion Lavoisier – foundations of chemistry
1500 – 18001500 – 1800
Daniel Fahrenheit – temperature scale George Hadley – influence of Earth’s rotation on
winds in the tropics Celsius – centigrade temperature scale Ben Franklin – nature of lightning Horace deSaussure – hair hygrometer for
measuring humidity Jacques Charles – relationship between
temperature and the volume of air
1800 to the present1800 to the present Ekman - Mathematical models for atmospheric motion 1821 – First crude weather maps 1835 – George Coriolis – affect of Earth’s rotation on atmospheric motion 1843 - Telegraph invented – transmission of weather observations 1920 – concept of air masses 1940’s – upper air balloon observations and discovery of the jet stream Post World War II – surplus radars used for weather 1950 – the first computer weather predictions by high speed computers 1960 – First weather satellite Tiros I 1990’s – Doppler Radar Investigations of the vertical structure of the atmosphere Sodars, lidars, radar, airplanes, satellites Super computers
Ancient ExperimentersAncient Experimenters
Eratosthenes – 330 BC – calculated the circumference of the Earth as 41, 660 km (today we know it to be 40,000 km)
Ancient ExperimentersAncient Experimenters
Ptolemy (100 – 160) sexagesimal system of one hour equal to 60 minutes and each minute equal to 60 seconds
Fostered the advancement of science and established the great library in Alexandria.
Founded a university dedicated to Muses (Goddess of the Arts) called the Museum
Ancient ExperimentersAncient Experimenters
Thales of Miletus – olive crop predictions based on weather observations (620 – 540 B.C.)
Genghis Khan defeated by Kublai Khan because a typhoon came along and destroyed his warships (the word Kamikaze which means “divine wind” came from this storm.
More StoriesMore Stories
Napoleon defeated at Waterloo because of bad weather that turned the battlefield into a swamp
Meteorology and the artsmany connectionssongs and lyrics (Vivaldi’s Four
Seasons)works of artliterature – Romeo and Juliet story hinged on the influence of a hot daymovies
Monitoring the WeatherMonitoring the Weather
Sources of Weather Sources of Weather InformationInformation
The media: radio, television, newspapers, cell phones, iPods, the internet
Our senses: observation and feelingWord of mouthEducated UnderstandingThe “Weather Channel” – 24- hours a dayNOAA Weather Radio – 24-hours a day
– Need a special radio
Weather Systems and Weather Systems and Weather MapsWeather Maps
National and Regional weather mapsSatellite or radar imagesData on current and past weather conditionsShort term weather forecasts (24-48 hours)Long term weather forecasts (up to 5 days
or longer)
What’s included on a weather What’s included on a weather map?map?
TemperatureDewpointWindAir pressurePrinciple weather maker (pressure systems
and fronts)
Pressure SystemsPressure Systems
High Pressure called an anticyclone and represented by a blue H
Low Pressure called a cyclone and represented by a red L
Think of air pressure as the weight of a column of air that stretches from the Earth’s surface to the top of the atmosphere
The use of High and Low Pressure are relative terms
High PressureHigh Pressure
Usually means fair weather
Highs that originate in NW Canada bring cold, dry weather in the winter and cool, dry weather in the summer
Highs that develop in the south bring hot, dry weather in the summer and mild, dry weather in the winter
High PressureHigh Pressure
If viewed from above the winds blow in a clockwise and outward direction (in the Northern Hemisphere)
Calm conditions or light winds are typical over a broad area about the center of the high
Low PressureLow Pressure
Lows produce cloudy, rainy or snowy weather (except in summer if they form over arid terrain)
Surface winds blow in a counterclockwise and inward spiral (in the Northern Hemisphere)
Pressure CentersPressure Centers
Move with the prevailing wind several kilometers above the surface (generally eastward in North America)
As they move they cause the weather to change
Highs follow lows and lows follow highsHigh generally track towards the E and SELows generally track towards and E and NE
Pressure CentersPressure Centers
Lows that track across the northern US usually produce less rain or snowfall than lows that track further south
Weather to the left side (west and north) of a storm’s track tends to be relatively cold
Weather to the right (east and south) of a storm’s track tends to be relatively warm