Transcript WHAT IS WEATHER?

WHAT IS WEATHER?
THE CONDITION OF
THE ATMOSPHERE
MEASURE TEMPERATURE
MEASURE PRESSURE
MEASURE WIND
MEASURE MOISTURE
What is the atmosphere?
• blanket of gases that surrounds the
Earth
– 79% nitrogen, 20% oxygen, 1% argon and
others
– Water vapor varies
• held in place by gravity
• divided into 5 layers
• Gas densities and quantities change
with altitude
EXOSPHERE
THERMOSPHERE
MESOSPHERE
STRATOSPHERE
TROPOSPHERE
TROPOSHERE
•
•
•
•
•
•
CONTAINS 90% OF ATMOSPHRE
CONTAINS ALL WATER VAPOR
CLOUDS FORM
8-16 KM (5-10 MILES) THICK
THICKER AT EQUATOR THAN POLES
STEADY DECREASE IN TEMPERATURE
WITH ALTITUDE
• WEATHER OCCURS HERE
STRATOSPHERE
• BOTTOM OF STRATOSPHERE IS JET
STREAM - STEADY WIND OF 50 - 250
MPH
• NO VERTICAL MOVEMENT OF AIR - NO
WEATHER PATTERNS
• EXTENDS 50 KM ( 30 MILES ) UP
• TEMPERATURE INCREASES DUE TO
ABSORBING ULTRAVIOLET LIGHT
• CONTAINS OZONE LAYER
MESOSPHERE
•
•
•
•
EXTENDS 80 KM ( 50 MILES ) UP
THIN GAS
ABSORBS LITTLE RADIATION
GETS COLDER WITH ALTITUDE
THERMOSPHERE
• EXTENDS UP TO 500 KM ( 310 MILES)
• VERY THIN GAS
• HIGH ALTITUDE EXPOSES TO LARGE
QUANTITY OF SOLAR RADIATION
• VERY HIGH TEMPERATURES (2000C)
EXOSPHERE
• OUTERMOST REGION OF THE
ATMOSPHERE
• NO TRUE “TOP” TO ATMOSPHERE
http://radar.metr.ou.edu/OK1/meteorology/VertStructure2.html
WEATHER FUELED BY:
SOLAR
RADIATION
CLOUDS AND GASES IN THE
ATMOSPHERE CAN REDUCE THE
AMOUNT OF SUNLIGHT REACHING
THE EARTH BY ABSORBING IT OR
REFLECTING IT.
THE AMOUNT THAT IS REFLECTED
OR ABSORBED BY THE EARTH
DEPENDS ON THE SURFACE.
Surface Reflects
Snow
75%
Water 60% - 95%
Sand
25%
Grass
10%
Absorbs
25%
5%-40%
75%
90%
LIGHT THAT IS ABSORBED BY
THE EARTH’S SURFACE
WARMS THE EARTH
WARM EARTH RADIATES
BACK HEAT (INFRARED
LIGHT)
TERRESTRIAL
RE-RADIATION
WARMTH FROM EARTH’S
SURFACE WARMS THE AIR
SOME HEAT THAT THE
EARTH RADIATES GETS
TRAPPED BY CLOUDS
An actual
Greenhouse
The Earth Greenhouse
CONVECTION
COOLING
RISES
EXPANSION
DEFLATION
FALLS
HEATING
CONVECTION
- transfer of heat through fluid flow