See it here. - Department of the Earth Sciences

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Transcript See it here. - Department of the Earth Sciences

Scott M. Rochette, Ph.D.
Associate Professor and Chair
Department of the Earth Sciences
The College at Brockport
 Overview
 Earliest Observations
 Birth of a Science
 Refining Moments
 Important Forecasts
 The Advent of Technology
 What’s Next?
 Words to Live By (?)
Why is Weather Forecasting So Difficult?
 Imagine a rotating spherical envelope 25 miles deep, made of a
mixture of gases whose concentrations vary in space and time.
Place it around an astronomical object nearly 8000 miles in
diameter, with a bumpy surface.
Tilt the whole system back and forth with respect to its source of
heat and light, a nuclear reactor 93 million miles away.
Freeze it at the poles of its axis of rotation and intensely heat it
in the middle.
Imagine that the gas mixture continually receives inputs from
the surface below, generally calmly but occasionally from violent,
highly localized injections.
Subject the whole to tidal forces induced by the sun and a captive
After watching the system, try to predict its state at one location
on the sphere for a period of one to several days in advance.
(adapted from Ryan 1982)
Words to Live By 1
 Death by burning shall be the punishment for the
practice of weather forecasting. (17th Century English
Earliest Observations 1
 Babylonia, circa 650 BCE:
 attempted prediction of short-term weather changes
 based on clouds and optical phenomena (halos, etc.)
Earliest Observations 2
 Greece, circa 340 BCE:
 Aristotle wrote Meteorologica, a four-volume philosophical
 included theories regarding the formation of clouds, rain and
hail, wind, thunder and lightning, and hurricanes
 also addressed astronomy, geography, and chemistry
 observations were remarkably acute, despite significant
did not believe wind was air in motion
believed that the west winds are cold because they blow from the
 the authority on weather theory for about 2000 years (until
WHAM 13)
Earliest Observations 3
 China, circa 300 BCE:
 astronomers developed calendar
 divided the year into 24 festivals, each corresponding to
a different type of weather
 India, circa 500 AD:
 Varahamihira wrote Brihat Samhita, “Great
 106 chapters
 theorized that rain comes from the sun
Birth of a Science 1
 Science implies reproducible results
 requires observations and measurements
 knowledge to this point based solely on observations
 development of weather instruments transformed
meteorology into a natural science
 First weather ‘instrument?’
 1450: first ‘hygrometer’
Cardinal Nicholas de Cusa of Germany
measured the weight change of a bag of wool
First Weather Instruments 1
 1590s: first ‘thermometer’
 Galileo Galilei of Italy
 glass spheres filled with
alcohol (of slightly different
 technically a ‘thermoscope’
(no scale, only registers
temperature differences)
 first scale would be added
about 20 years later
First Weather Instruments 2
 1643: first barometer
 Evangelista Torricelli of Italy
(student of Galileo)
 pump makers noted that they could
get water to rise only about 10 meters
 filled a glass tube with mercury
(density 14x higher than water) and
inserted it into a dish
 found that the height of the mercury
column rose and fell with changes in
atmospheric pressure
 By allowing atmospheric
measurements to be made,
‘meteorology’ became a science
Synoptic Weather Reports
 One could only do so much with
weather information (observed or
measured) for a single location
 The telegraph (invented in 1837)
allowed weather information to
be exchanged and collected
 Simultaneous (synoptic) weather
observations became the basis for
understanding and forecasting
the weather
 ‘Synoptic’ = ‘to view together’
What did this do?
 Plotting synoptic observations on a map
began to show repeating patterns and
 storms were known to be associated with low
pressure, but no relationship between wind
and pressure was established
 William Redfield (1831) postulated that
winds in hurricanes flow counterclockwise
around a low-pressure center (based on a
pattern of fallen trees)
 James Espy (1841) theorized that air flows
toward low pressure and is forced to rise,
leading to clouds and precipitation
 The establishment of weather maps proved
both men correct
Weather Maps
 First daily weather map series
produced by Joseph Henry of
the Smithsonian Institution
 Started in 1849 with a network
of 150 volunteer observers
 10 years later, the network
quadrupled in size, including
observers in Canada, Mexico,
Latin America, and the
 Precursor to the National
Weather Service
‘Murphy’s Winter’
 Some of the first weather forecasts were produced
based on theories of planetary or lunar influences (i.e.,
not based on meteorological observations)
 Patrick Murphy of Ireland was one of the more
‘famous’ astrologer-meteorologists
 In 1837, he published The Weather Almanack (on
Scientific Principles, showing the State of the Weather
for every day of the year 1838)
 His forecast for 20 January 1838, ‘Fair, probably lowest
degree of winter temperature’
So How Did He Do?
 His forecast for London on 20 January 1838 was correct
(temperature at sunrise was -4˚F)
As a result, his almanac was a best-seller, with a run of
45 editions (making him £3,000, a fortune then)
However, an analysis of his 1838 performance showed
him to be ‘partially right’ on 188 days, but completely
wrong on 197 days (54% of the year)
He published almanacs for the next several years,
which made him a decent living
Poor speculating on grain prices cost him most of his
Vice-Admiral Robert FitzRoy
 Likely best known as the captain of the
HMS Beagle (Darwin)
Appointed in 1854 to the position of
‘Meteorological Statist to the Board of
Trade,’ in charge of collecting weather data
from ships at sea
A storm in 1859 that caused the loss of a
clipper ship (450+ lost, 39 survivors)
inspired him to create weather charts
(similar to those made by Henry)
These charts were used to make
predictions of storms, which he called
‘forecasting the weather’
Daily forecasts began to be published in
The Times in 1860
Likely the first weather forecasts based on
meteorological observations
A Sad End for FitzRoy
 During that time, the standard for forecasting was set by the Royal
Landmark accomplishments of Newton (1643-1727) and Leibniz (16461716) ushered in an era of determinism
“If we can imagine a consciousness great enough to know the exact
locations and velocities of all the objects in the universe at the present
instant, as well as all forces, . . . It could calculate anything about the
past or future from the laws of cause and effect.” (P.-S. Laplace)
Even though they were based on actual meteorological data, FitzRoy’s
forecasts were not up to this standard
The damage from astrologer-meteorologists caused distrust of
government forecasts by the public and colleagues alike (unlike today,
of course)
Forced to abandon his efforts, FitzRoy committed suicide on 30 April
Professor Cleveland Abbe
 Director of the Cincinnati Observatory
 Set up a volunteer observer network
similar to that of Joseph Henry
Selected observing equipment and trained
Clerks would decode incoming data and
plot them on maps
Abbe gave the first official U.S. forecast on
19 February 1871
He demanded that his team’s forecasts
were precisely worded and covered four
key elements: temperature, pressure, wind
direction, and weather (clouds/
69% of their forecasts verified
Abbe’s Accomplishments
 First Chief Scientist of newly formed
‘national weather service’ under U. S.
Army Signal Corps (1871-1915)
 Advocated for the establishment of
time zones in the U.S. and North
America (thereby allowing
simultaneous weather observations)
 Founded Monthly Weather Review in
1872 (still in print!)
 Recognized the interdependence of
forecasting, climatology, and physical
theory (to the chagrin of meteorology
students ever since)
Early U.S. Weather Map, 1 January 1871 (courtesy of NOAA)
Words to Live By 2
 “Probably northeast to southwest
winds, varying to the southward
and westward and eastward and
points between, high and low
barometer swapping around from
place to place; probable areas of
rain, snow, hail, and drought,
succeeded or preceded by
earthquakes, with thunder and
lightning.” (Mark Twain, 1876, on
Professor Abbe’s likely weather
forecast for New England)
Words to Live By 3
 “He who shall predict weather will
have no quite life any more, and
runs great risk of becoming crazy
from nervousness.”
 (C. H. D. Buys Ballot, author of the
Buys Ballot law)
From Empiricism to Determinism
 Physical laws govern the motion of fluids (e.g., atmospheric
 M. F. Spaaskii (1851), a Russian meteorologist, posed the
idea that weather forecasting can be posed as a
mathematical problem
 Prof. Abbe (1890) published Preparatory Studies of
Deductive Methods in Storm and Weather Predictions,
which furthered the idea that the laws of physics could be
applied to weather prediction
 Henrik Mohn (Norway), Wladimir Köppen (Germany), and
Max Margules (Ukraine) postulated that upper-level
mechanisms generate energy for storms
Words to Live By 4
 “Forecasting is immoral and
damaging to the character of a
meteorologist.” (Max Margules)
Professor Vilhelm Bjerknes
 The pioneer of modern weather
 His 1904 paper provided the basis for
numerical weather prediction some 50
years before the first computer model
 The future state of the atmosphere can
be determined given:
 the initial conditions of the
 appropriate governing equations
 Established the Bergen School of
Meteorology in 1917
 Son Jacob would also contribute
Lewis Fry Richardson
 The first person to attempt numerical
weather prediction (1922, without a
 A Quaker and a pacifist:
 he served in WWI as an ambulance driver
 developed his theories about NWP during
this time
 Attempted a forecast of pressure change
(from 4 am to 10 am 20 May 1910, near
 six-hour forecast took six weeks
 predicted pressure change: 145 mb!
 actual pressure change: < 1 mb
 greatest range of observed pressure ~100 mb
Richardson’s Forecast Factory
 Aside from the time problem,
Richardson used the full equations
 should have neglected small-scale
 think of a jar filled with rocks of
different sizes
 He figured about 64,000 people (with
hand calculators) would be needed to
keep up with the world’s weather
 envisioned a giant theatre to house
 the light would shine on ‘areas’ that
needed to slow down or speed up
 Gave up weather and focused on
‘peaceful’ pursuits
 Lived to see the first successful NWP
Professor Jacob Bjerknes
 Member of the Bergen School
 Published a paper in 1922 (at 25!)
establishing the Norwegian cyclone
 extratropical cyclone life cycle
 cold, warm, occluded fronts
 still used today
 Founded the UCLA Department of
Meteorology in 1940
 one of five meteorology departments
formed that year
 MIT, Cal Tech, NYU, University of
Further Advances…
 1930s: Radiosondes make upper-
air data available in near-real
 1930s-WWII: Radar first
developed as method for tracking
ships and aircraft
 WWII: Weather found as ‘noise’
in radar imagery
Some Important Forecasts
 June 1944: Operation Overlord
 Captain John Stagg, RAF
 Eisenhower wanted five-day
forecasts (!)
 Weather requirements:
no fog/low clouds
<60% cloud cover
winds < 20 mph
no high seas
onshore winds < 12 mph
D-Day Forecast
 5 June 1944 was originally chosen (moonlight and very low
No-go decision made ~4:30 am on 4 June
Forecast: 6 June would be relatively calm with good
visibility, followed by several days of variable weather
Eisenhower, 5 June 1944: “…our little camp was shaking and
shuddering under a wind of almost hurricane proportions
and the accompanying rain seemed to be traveling in
horizontal streaks.”
Storm also prevented German reconnaissance missions
Germans thought invasion unlikely because of the stormy
weather on 5 June, and did not foresee the interval of
acceptable weather on 6 June
Many problems with invasion, but few due to weather
First Tornado Forecast
 20 March 1948: Tinker AFB hit by tornado
 32 aircraft destroyed
 several injuries in control tower
 $10M+ damages (in 1948 dollars)
 Commander ordered a study on tornado-
producing thunderstorms
 On 25 March 1948, Fawbush and Miller
noticed similarities between current
conditions and those of 20 March
 Hesitantly issued tornado forecast at 2:50
 Tornado struck Tinker shortly after 6 pm
 $6M damages
First Weather Broadcasters
 E. B. Rideout, 1926 (WEEI radio,
Boston, MA)
 Jim Fidler, 1934 (WBLC radio,
Muncie, IN)
 Jim Fidler, 1947 (TV, Dumont
Network, later WLWT, Cincinnati)
The Age of Computers
 1946: the first electronic
computer (ENIAC) is developed
at the University of
 That same year, meteorologists
pose that the computer should
be used for weather forecasting
 Jule Charney named director of
the Weather Project in 1948,
which attempted the first
weather forecast by computer
The First NWP Model
 1950: the first numerical weather prediction (NWP)
model is run on ENIAC
 ~30 minutes to make computations
 actual forecast took more than 24 hours due to
punchcard loading and machine breakdown
 Actual 24-h forecast was quite good!
The View from Space
 4 October 1957: the Soviet
Union launched Sputnik I,
the first artificial satellite
 1 April 1960: the U.S.
launched TIROS 1, the first
successful weather satellite
What now?
 Technology marches on
 faster computers → more (and more accurate) NWP models
started with a single (simple) model in 1950s
number of available models now in double digits
more realistic simulation of large- and small-scale weather features
 more (and more complete) weather observations
 observations used to be taken by people
 automation has improved spatial/temporal coverage
 radar and satellite observations improve
 one type each of radar and satellite imagery, limited coverage
 multiple radars (NWS, TV stations) and radar products
 multiple satellites and products cover major fraction of globe
 Internet (for better or worse)
 world-wide weather information readily available in real-time
 provides a better forum for complaints?
What’s next?
 Science/technology continue to advance weather
 more/faster information transfer via advances in
communications technology
more timely, more focused forecasts
ditto for warnings
 weather ‘mysteries’ solved?
 small-scale weather features and their consequences
 formation mechanisms for destructive weather systems
 probabilistic weather forecasts
 range of possibilities as opposed to deterministic forecasts
 accounting for (relative) uncertainty
Do we really know what we’re doing?
Perhaps we really do…sort of
 We have come a long way in the past 2000+ years
 Weather forecasting has evolved:
 from simple observations…
 …through empirical relationships…
 …to science-based predictions
 Yes, we have more challenges ahead of us
 will we overcome them?
 wait and see…ask me back in fifty years!