Transcript weather and climate

WEATHER AND CLIMATE
Weather is a great metaphor for life - sometimes it's good,
sometimes it's bad, and there's nothing much you can do
about it but carry an umbrella. ~Pepper Giardino
WEATHER IS THE COLLECTION OF FACTORS THAT
DESCRIBE THE ATMOSPHERE AT ANY GIVEN TIME.
THESE INCLUDE TEMPERATURE, BAROMETRIC
PRESSURE, WIND DIRECTION, WIND VELOCITY,
PRECIPITATION, RELATIVE HUMIDITY, WIND CHILL,
CLOUD TYPE, CLOUD COVER, SUNSHINE, ETC.
CLIMATE IS WEATHER AVERAGED OVER A LONG
PERIOD OF TIME IN A GIVEN REGION.
IT’S WHAT WE WOULD EXPECT THE WEATHER TO
BE LIKE FROM YEAR TO YEAR.
HUMANS HAVE BEEN INTERESTED IN THE WEATHER
SINCE THERE WERE HUMANS.
BEFORE WE KNEW MUCH ABOUT THE WEATHER, IT
PLAYED A PART IN RELEGION.
ZEUS WAS THE GREEK GOD OF LIGHTNING.
INDRA WAS THE HINDU GODDESS OF
THUNDERSTORMS.
THE PRIESTS WERE THE SCIENTISTS OF THEIR DAY,
AND PEOPLE LOOKED TO THEM FOR HELP WITH
THE WEATHER.
HUMANS BEGAN TO SEE PATTERNS IN THE
WEATHER BY OBSERVING IT DAILY OVER LONG
PERIODS OF TIME.
SAILORS AND FARMERS BEGAN TO LOOK FOR
SIGNS THAT WOULD HELP TELL THEM WHAT THE
WEATHER WOULD BE.
IN THE 17TH CENTURY, SEVERAL INSTRUMENTS
WERE INVENTED THAT WOULD HELP - THE
THERMOMETER, THE BAROMETER, AND THE
HYGROMETER.
THOMAS JEFFERSON STARTED MAKING DAILY
WEATHER OBSERVATONS FROM THE TIME OF
THE DECLARATION OF INDEPENCENCE IN 1776
UNTIL HIS DEATH 50 YEARS LATER.
HE THOUGHT THAT THE LARGE NUMBER OF NEW
SETTLERS IN AMERICA MIGHT BE CHANGING THE
CLIMATE AND URGED THAT A NETWORK OF
WEATHER OBSERVATORIES BE SET UP.
IN THE 1850’S WITH THE ESTABLISHMENT OF
TELEGRAPH NETWORKS, WEATHER DATA COULD
BE COLLECTED FROM AROUND THE COUNTRY.
BY THE 1880’S THE U.S. ARMY SIGNAL CORPS OPERATED
154 WEATHER STATIONS NATIONWIDE AND SENT WEATHER
DATA TO WASHINGTON, DC THREE TIMES A DAY BY
TELEGRAPH.
SOME OF THE STATIONS WERE RESPONSIBLE FOR SENDING
WEATHER INDICATORS OUT TO THE SURROUNDING AREAS.
FOR EXAMPLE, THE STATION AT ST. PAUL, MN WAS
RESPONSIBLE FOR SENDING OUT WARNINGS OF COLD
WAVES AND BLIZZARDS TO THE NORTHERN PLAINS.
HOWEVER, THIS INFORMATION WAS TRANSMITTED BY
TELEGRAPH, SO ONLY PEOPLE WHO LIVED IN COMMUNITIES
ALONG RAILROAD TRACKS WOULD GET THE INFORMATION.
OFTEN, THIS WOULD BE IN THE NEXT DAY’S PAPER.
ON JANUARY 12, 1888 A MAJOR BLIZZARD HIT THE PLAINS.
WARM, MOIST AIR HAD MOVED UP FROM THE GULF, AND IT
COLLIDED WITH AN ARTIC COLD FRONT MOVING DOWN
FROM THE NORTH.
THE DAY HAD STARTED OFF RELATIVELY WARM, SO
PEOPLE WERE OUTSIDE WORKING THEIR FARMS, AND
CHILDREN WERE IN SCHOOL.
WHEN THE STORM HIT, TEMPERATURES DROPPED BY
AROUND 40o F. WINDS BLEW AT 40 MPH, AND THE SNOW
DROPPED VISIBILITY TO A FEW FEET.
THE STORM HIT NEBRASKA BETWEEN 2 AND 3 PM.
BETWEEN 250 AND 500 PEOPLE DIED – MANY OF THEM
WERE CHILDREN.
THE STORM IS KNOWN AS “THE CHILDREN’S BLIZZARD.”
TRAIN STALLED AS A RESULT OF
THE BLIZZARD
ANOTHER BIG BLIZZARD TOOK PLACE THAT SAME
YEAR – 12-14 MARCH, 1888. A HUGE
NORTHEASTER MOVED UP THE COAST HITTING
NEW YORK AND NEW ENGLAND WITH HEAVY
SNOW AND HIGH WINDS.
SINCE THE STORM MOVED UP OFF SHORE, NO
ONE WAS ABLE TO PREDICT IT.
AN ESTIMATED 300 PEOPLE IN NYC LOST THEIR
LIVES.
ABOUT 200 SHIPS WERE SUNK AND NEARLY
100 LIVES WERE LOST AT SEA.
ANOTHER UNFORSEEN WEATHER EVENT WE
WILL DISCUSS LATER IS THE 1900 GALVESTON
HURRICANE IN WHICH 6,000 PEOPLE LOST
THEIR LIVES.
RADIO IMPROVED THIS.
RADAR WAS INTRODUCED DURING WORLD WAR
2, AND THIS ALLOWED METEOROLOGISTS TO
WATCH THE DEVELOPMENT OF WEATHER.
IN THE 1970’S WEATHER SATELLITES ADDED TO
THE TOOLS, AND WEATHER COULD BE
INSTANTLY OBSERVED OVER LARGE AREAS.
SUPER COMPUTERS ADDED TO THE ABILITY TO
MAKE MORE ACCURATE PREDICTIONS.
WEATHER IS THE MOVEMENT OF AIR MASSES
DRIVEN BY THE SUN.
EACH OF THESE AIR MASSES ARE AT DIFFERENT
TEMPERATURES AND CONTAIN DIFFERENT
AMOUNTS OF MOISTURE.
ONE AIR MASS WILL INFLUENCE AND BE
INFLUENCED BY OTHER AIR MASSES.
IT IS A VERY COMPLEX SYSTEM.
SO COMPLEX THAT CHAOS THEORY TALKS
ABOUT THE “BUTTERFLY EFFECT.”
ALL WEATHER TAKES PLACE IN THE
TROPOSPHERE.
THE TROPOSPHERE IS 10 TO 14 KM HIGH.
IT CONTAINS ABOUT 75% OF THE MASS OF THE
ATMOSPHERE AND 99% OF THE WATER VAPOR.
THIS ENERGY IS NOT EQUALLY DISTRIBUTED
OVER THE SURFACE OF THE EARTH.
THE EARTH’S AXIS IS TILTED AT 23.5o RELATIVE TO
OUR ORBIT ABOUT THE SUN.
THIS GIVES US OUR SEASONS.
DIFFERENTIAL
HEATING ALSO
LEADS TO
WINDS AND
WIND
PATTERNS ON
BOTH A LOCAL
AND A GLOBAL
LEVEL.
CORIOLIS
EFFECT
CAUSES
WINDS TO
BEND TO THE
RIGHT IN THE
NORTHEN
HEMISPHERE
AND TO THE
LEFT IN THE
SOUTHERN
HEMISPHERE.