Transcript WEATHER, WHY WORRY ABOUT IT?

WEATHER, WHY WORRY ABOUT IT?
PICTURES MADE IN MISSISSIPPI AS
KATRINA MOVED IN
WHY SHOULD WE BE CONCERNED OR WORRY
ABOUT WEATHER?
WHY SHOULD WE WANT TO MEASURE
“WEATHER”, KEEP RECORDS OF WEATHER, AND
TRY TO PREDICT WEATHER?
12 JANUARY 1888 – FIERCE BLIZZARD SWEPT DOWN ON
NEBRASKA AND THE DAKOTA TERRITORY.
WIND CHILL DROPPED TO -40o F. BEFORE IT HIT, IT HAD BEEN
A MILD DAY.
THE WEATHER OFFICE IN ST. PAUL, MN HAD PREDICTED IT,
AND SENT OUT A WARNING BY TELEGRAPH. MOST PEOPLE
LIVED FAR AWAY FROM TELEGRAPH LINES AND OFFICES.
POSSIBLY AS MANY AS 500 PEOPLE DIED – MANY LOST IN
THE STORM, AS VISIBILITY DROPED TO ZERO.
KNOWN AS THE “CHILDREN’S BILIZZARD, AS MANY KIDS
WERE LEAVING SCHOOL WHEN IT HIT.
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.
THE GREAT BLIZZARD OF
1888
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 WAS
THE 1900 GALVESTON HURRICANE IN WHICH
6,000 PEOPLE LOST THEIR LIVES.
SO, WHAT’S WEATHER??
WEATHER “THE STATE OF THE ATMOSPHERE
AT SOME PLACE AND TIME.”
- Joseph Moran, “Weather Studies” –
WE ATTEMPT TO DESCRIBE WEATHER IN
QUANTITATIVE TERMS – TEMPERATURE,
HUMIDITY, CLOUDINESS (TYPE AND COVER),
PRECIPITATION (TYPE AND AMOUNT), WIND
SPEED, WIND DIRECTION.
THE ACTUAL SCIENCE THAT STUDIES
WEATHER IS METEOROLOGY – “STUDY OF THE
ATMOSPHERE AND THE PROCESSES THAT
CAUSE WEATHER.”
CLIMATE – “ARITHMETIC AVERAGES OF
WEATHER ELEMENTS TAKEN OVER YEARS”
- JOSEPH MORAN –
AVERAGES ARE TAKEN OVER A 30 YEAR PERIOD
BEGINNING WITH THE 1ST YEAR OF A DECADE.
CLIMATE GOVERNS MAY THINGS, EVEN THE
TYPE OF ECOSYSTEM.
CLIMATE DETERMINES: THE FRESH WATER
SUPPLY, HEATING AND COOLING
REQUIREMENTS, CLOTHING AND HOUSING
REQUIREMENTS, TYPES OF FOOD THAT CAN BE
GROWN, ETC.
WHERE DO WE GET WEATHER
INFORMATION?
WHERE DO WE GET WEATHER
INFORMATION?
1)TV
2)RADIO
3)NEWSPAPERS
4)INTERNET
5)NOAA WEATHER RADIO
6)PERSONAL OBSERVATION
NOAA – NATIONAL OCEANIC AND ATMOSPHERIC
ADMINISTRATION (NATIONAL WEATHER SERVICE
IS PART OF THIS)
WHERE DOES NOAA GET ITS WEATHER
INFORMATION?
1)ASOS – AUTOMATED SURFACE OBSERVING
SYSTEMS
2)RADAR
3)SATELLITES
4)SHIPS AND BOUYS
SOME OF THE DATA MIGHT INCLUDE:
1)MAXIMUM TEMPERATURE – HIGHEST TEMPERATURE
RECORDED OVER A 24 HOUR PERIOD – GENERALLY
OCCURS EARLY TO MID AFTERNOON
2)MINIMUM TEMPERATURE – LOWEST TEMPERATURE
OVER A 24 HOUR PERIOD – USUALLY AROUND
SUNRISE
3)DEW POINT – TEMPERATURE, ON COOLING, WHERE
THE AIR BECOMES SATURATED WITH WATER VAPOR –
TEMP. AT WHICH DEW OR FROST WOULD FORM
4)PRECIPITATION AMOUNT – DEPTH OF RAINFALL OR
SNOWFALL IN INCHES OVER A 24 HOUR PERIOD (10 “
OF SNOW = 1 “ OF RAIN
5)AIR PRESSURE – WEIGHT OF A COLUMN OF AIR
OVER A UNIT AREA OF EARTH
6)WIND DIRECTION AND SPEED – DIRECTION FROM
WHICH THE WIND IS BLOWING
7) CLOUD TYPE AND COVER
8) RELATIVE HUMIDITY – THE AMOUNT OF MOISTURE IN
THE AIR DIVIDED BY THE MAXIMUM AMOUNT AT THAT
TEMPERATURE TIMES 100
9) BAROMETRIC PRESSURE
NWS ASOS STATIION
WEATHER CONDITIONS ARE
REPORTED AND USED TO
UPDATE THE FORECAST 12
TIMES EACH HOUR.
Sky conditions such as cloud height and cloud amount up to 12,000 feet,
Surface visibility up to at least 10 statute miles,
Basic present weather information such as the type and intensity for rain, snow,
and freezing rain,
Obstructions to vision like fog, haze, and/or dust,
Sea-level pressure and altimeter settings,
Air and dew point temperatures,
Wind direction, speed and character (gusts, squalls),
Precipitation accumulation, and
Selected significant remarks including- variable cloud height, variable visibility,
precipitation beginning/ending times, rapid pressure changes, pressure change
tendency, wind shift, peak wind.
RADIOSONDES (WEATHER
BALLOONS) ARE USED TO MAKE
UPPER AIR OBSERVATIONS. THE
NWS OPERATES 92 STATIONS IN
THE U.S. AND OBSERVATIONS
ARE MADE TWICE DAILY.
THE BALLOONS WILL ASCEND TO
115,000 FEET. WHEN THE
BALLOON BURSTS, A PARACHUTE
WILL DEPLOY TO GET THE
INSTRUMENT PACKAGE TO EARTH
SAFELY.
APPROXIMTELY 20% ARE
RETURNED EACH YEAR.
WEATHER SATELLITES
POLAR ORBITING SATELLITES (POES):
ADVANTAGES – ORBIT AT APPROXIMATELY 520 MILES
ABOVE THE SURFACE, GIVE DETAILED IMAGES, GIVE
IMAGES OF THE POLAR REGIONS
DISADVANTAGES - PATH OF SATELLITE CHANGES WITH
EACH ORBIT
GEOSTATIONARY SATELLITES (GOES):
ADVANTAGES: ALWAYS LOCATED IN THE SAME SPOT,
SO CAN CONTINUOUSLY OBSERVE MOTIONS OF CLOUDS
DISADVANTAGES: LOCATED APPROXIMATELY 22,000
MILES ABOVE SURFACE, SO LESS DETAIL, AND NO VIEW
OF POLAR REGIONS
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.
THE SUN PROVICES THE ENERGY.
BUT THE CAUSE IS UNEVEN HEATING OF THE EARTH’S
SURFACE. THE SURFACE IS HEATED UNEVENLY FOR
THREE REASONS:
1.TILT OF THE EARTH ON ITS AXIS.
2.NIGHT ON ONE SIDE AND DAY ON THE OTHER.
3.DIFFERENT SURFACE MATERIALS HEAT AT DIFFERENT
RATES.
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.