Transcript History of Meteorology

History of Meteorology
Three General Historical
Periods
Ancient
Times: 600 B.C. to
1500 A.D.
1500 A.D. to 1800 A.D.
1800 A.D. to Modern Times
Meteorology
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Word was invented by the Greeks over 200 years
ago (Aristotle)
meta = beyond
eora = suspension
Meteoros = high in the air
Aristotle 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
Atmosphere
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Also comes from the Greek
Atmos = Vapor
The atmosphere is a region of vapor
Ancient Period 600 B.C. to
1500 A.D.
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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 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
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Ancient Period
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Greeks – developed geometry, logic and
philosophy – also performed meteorological
observations and created physical theories
Hippocrates: study of climate
Aristotle: Meteorologica
Theophrastus: meteorological treatise
Ancient Period
Romans – didn’t contribute much except in
the field of organization, law, medicine,
agriculture and the building of aqueducts
Seneca – interested in meteorology
 Middle Ages – stagnation in the arts and
sciences – burned the library in Alexandria
 Arabs – mathematics, optics and astronomy
and the number system
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A Water-Clock
1500 – 1800
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Age of Genius and the Age of Reason
 Copernicus – heliocentric theory of the
universe
 Foundations of modern meteorology laid in
Europe with the invention of meteorological
instruments and the introduction of
meteorological observations
1500 – 1800
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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 – 1800
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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 present
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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 Experimenters
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Eratosthenes – 330 BC
– calculated the
circumference of the
Earth as 41, 660 km
(today we know it to
be 40,000 km)
Ancient Experimenters
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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 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.
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More Stories
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Napoleon defeated at Waterloo because of bad
weather that turned the battlefield into a swamp
 Meteorology and the arts
many connections
songs and lyrics (Vivaldi’s Four
Seasons)
works of art
literature – Romeo and Juliet story hinged on
the influence of a hot day
movies
Monitoring the Weather
Sources of Weather
Information
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The media: radio, television, newspapers,
cell phones, iPods, the internet
 Our senses: observation and feeling
 Word of mouth
 Educated Understanding
 The “Weather Channel” – 24- hours a day
 NOAA Weather Radio – 24-hours a day
– Need a special radio
Weather Systems and
Weather Maps
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National and Regional weather maps
 Satellite or radar images
 Data on current and past weather conditions
 Short term weather forecasts (24-48 hours)
 Long term weather forecasts (up to 5 days
or longer)
What’s included on a weather
map?
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Temperature
 Dewpoint
 Wind
 Air pressure
 Principle weather maker (pressure systems
and fronts)
Pressure Systems
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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 Pressure
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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 Pressure
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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 Pressure
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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 Centers
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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 highs
 High generally track towards the E and SE
 Lows generally track towards and E and NE
Pressure Centers
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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