Weather
The condition of Earth's atmosphere at a particular time and place.
atmosphere
gases that envelope Earth
the atmosphere consists of
nitrogen, oxygen, carbon dioxide, water vapor, other gases, liquids and solids
oxygen
21 percent
nitrogen
78 percent
argon and trace gases
<1 percent
water vapor
not same as steam (tiny droplets of liquid water)
Clouds
Form when water vapor in the air condenses to form liquid water or ice crystals
Rain or snow
form when droplets become heavy enough and contain dust, smoke, salt, and chemicals
Atmosphere system
Clouds, Air, Wind and NRG from the sun. Events in one part of the atmosphere effect the others
Air
has molecules and atoms therefore it has mass and density and pressure.
Density
mass per volume
pressure
the force pushing on area or surface
air pressure
result of weight of a column of air pushing on an area.
Barometer
instrument used to measure air pressure
two types of Barometers
mercury and aneroid
Mercury Barometer
long glass tube closed at one end and open at the other which is in a dish of mercury. Closed end has little air to the air pressure forces the column of mercury higher in the tube. LEVEL OF MERCURY in the tube shows the pressure of the air that day.
aneroid barometer
airtight metal chamber where the walls push IN when there's air pressure. Pressure DROPS walls bulge OUT. chamber shape changes the NEEDLE on the dial.
Weather reports
use inches in mercury to determine air pressure
National Weather Service
Use millibars to represent the airpressure
one inch of mercury
is 33.86 millibars
Altitude
Elevation above sea level
Altitude increases
density and air pressure decrease because there are fewer oxygen molecules.
Thermal NRG
total measurement of how fast particles move
Temperature
average measurement of how fast particles move
Thermometer
measures temperature in degrees Celsius or Fahrenheit
Fahrenheit to Celsius
F=9/5C+32
Heat
thermal NRG transferred from a hotter object to a colder one.
Three ways heat is transferred
conduction, convection, radiation
Conduction
transfer of heat by direct contact example: toilet seat
Convection
The transfer of heat by the movement of a fluid Example: Lava lamp and mantle
heat transfer
fast moving molecules bump into slower ones and transfer their NRG to them.
Why do some solids have more conduction?
the closer together molecules are in a substance the better they conduct heat. Works best with metals, not liquids or gases.
Radiation
direct transfer of NRG by electromagnetic waves.
Infared radiation
heat from the sun which you cannot see but you can feel.
Convection currents
the upward movement of warm air and the downward movement of cool air. Also how heat is transferred in the troposphere.
electromagnetic waves
A form of energy that can move through the vacuum of space.
ultraviolet radiation
another form of radiation from the sun. invisible form of radiation with wavelengths shorter than violet light
electromagnetic spectrum
gamma rays---Xrays---ultraviolet---visible light---infared---microwaves---Radiowaves NRG increases towards gamma rays and the wavelength becomes shorter