1. Intro to the Atmosphere
The layers of gas that surround the other •
spheres of influence on our planet •
Interacts frequently with
Interacts frequently with • - -
Hydrosphere- Clouds,Humidity,Rain
Hydrosphere- Clouds,Humidity,Rain
Lithosphere
- Weathering,Wind Erosion,Dust Particles - -
Lithosphere
- Weathering,Wind Erosion,Dust Particles - -
Exosphere
Exosphere
- Blocks incoming Solar Radiation
- Blocks incoming Solar Radiation - -
Biosphere
Biosphere
- Us!, plants, animals
- Us!, plants, animals

2. How do we know about the atmosphere?
Measuring instruments • -
Thermometer- temperature -
Barometer- pressure -
Geiger Counter- radioactivity -
Chromatograph- chemical composition
Space missions • -
satellites -
aircraft
Theory • -
physics and chemistry

3. Origins of Earth’s atmosphere
Early on- volcanic activity is •
responsible for atmospheric gases -
rich in CO2 (carbon dioxide) -
very different from today’s atmosphere
simple plants and bacteria as planktonic life forms (phytoplankton) changed the atmospheric composition over 2 billion years • -
increased the oxygen content in oceans then air
Solar radiation also contributed • -
created other atoms by irradiating
existing components- ozone layer

4. Composition (modern) N (nitrogen) = 78 % O (oxygen ) = 21 %
Ar (argon) = 0.93 %
an inert gas CO
(Carbon Dioxide) = 0.035% 2
a greenhouse gas
Aerosols and Water
dust and moisture particles small •
enough to stay up in the atmosphere

5. The structure of the atmosphere Ionosphere Composition is
divided based on •
Ionosphere
the
temperature •
Composition is
unchanging here
Clouds
Ozone Layer O3
form
here

6. Aurora Borealis
& Australis
Ionosphere &
magnetosphere

7. AURORA BOREALIS movies

8. Factors associated with the atmosphere• -
different from temperature (avg. kinetic energy) -
usually measured as the temperature of the air -
F, C, K scales -
a function of the kinetic energy (molecular motion).
Moisture • -
Measured as relative humidity -
a function of temperature and availability -
expressed as a percentage
Pressure • -
Measured in millibars, pascals, or inches

9. Radiation- also known as radiative or
Heat transfer
One of the big things the atmosphere does!
Conduction
contact between air and ground •
Convection
mixing due to temp related density changes •
Radiation- also known as radiative or
electromagnetic energy
absorbed and emitted by all objects •

10. Convection (& Advection)
Conduction
Heat transfer (2)
contact between hot & cool • -
transfers E from hot to cool
solids > liquids > gases • -
atmosphere poor at
conduction
Convection (& Advection)
"mixing" of hot & cold • -
Usually in currents -
Con- is vertical; Ad- is horizontal or lateral

11. Radiation Sun is the source of most radiation • Earth also gives •-
visible light = intermediate-wave radiation -
infrared (heat)= Longwave radiation -
X-rays, gamma rays, etc= very shortwave
Earth also gives •
off some radiation
Living things also •
give off radiation
Angle of approach •
and reflective
properties are
critical factors

12. The "weight" of the air pressing down on the Earth's surface
Air Pressure
The "weight" of the air pressing
down on the Earth's surface
A simple barometer
measured by a Barometer • -
inches (or mm) of mercury
rising up in a tube
adjusted according to height •
above avg. sea level -
less air pressing down from above at higher
altitudes
also takes into account motion of air • -
sinking vs rising

13. Atmospheric Density 120 km 0 km air is "thinner" • aloft- less atoms
of it
Pressure is •
lower aloft
Important for •
heat
and
pressure
transfer
0 km

14. Surface isobar map with fronts

15. Moisture- the other main thing
dependent on temperature • -
warmer = hold more water vapor -
colder = holds less water vapor
results from • -
evaporation of liquid water -
cools surface and adds heat to air -
sublimation -
direct transformation from solid water
(ice) to vapor
Acts as a trap for longwave radiation (heat) •
Transports heat •
Acts to transport water •

16. Interaction of Radiation,Pressure,Moisture at macro, or global, scale

17. Weather patterns are dictated by moisture, pressure and temperature differences in various air masses
A hurricane (shown at right) is an extreme low pressure system that draws energy from warm water
Interaction of Radiation,Pressure,Moisture at meso scale

18. Sea Breeze- Interaction of Radiation,Pressure,Moisture at micro scale
animation