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.
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 SATTELITES 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.