AOSC 200

1
AOSC 200

• Lect 26 27, and final exam review

2
Polution

• SmokeFogSmog
• Hydrocrabon and NOx
• Strong sunlight
• Warm temperatures
• Peak O3 at warmest part of day
• Primary pollutants are emitted directly from
  identifiable sources. They pollute the air
  immediately upon being emitted.
• Secondary pollutants are produced in the
  atmosphere when certain chemical reactions take
  place among primary pollutants.
• Acid Precipitation
• Rain is naturally weakly acidic because CO2 from
  the atmosphere dissolves in water.
• Unperturbed rainwater has a pH of 5.6

3
Role of Atmospheric Stability
Inversions aloft (subsidence inversions) are
associated with prolonged, severe pollution
episodes. These types of inversions are caused
by the sinking air associated with the center of
high pressure systems (subsidence). As the air
sinks it is warmed adiabatically. Turbulence at
the very lowest part of the atmosphere prevents
subsidence from warming that portion of the
atmosphere. Los Angles pollution episodes as
well as those over the Mid-Atlantic region are
the result of inversions aloft associated with
strong high pressure systems.
4
Finale Exam

• 2/3 on material since the last exam
• 1/3 comprehensive
• Questions?