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.