2. We will discus about these topics.
Condensation And Precipitation.
Air Masses.
Storms.
Atmospheric Pollution.
Climate And Pollution.
3. Atmospheric Effects
The lower atmosphere (troposphere) is dynamic,
resulting in frequent weather changes
The movements and interactions of large air
masses bring variations to our weather
Large air masses can move thousands of miles
and influence a region for a considerable time
period
4. Condensation
Water droplets do not
form randomly, but form
around microscopic
foreign particles called
hygroscopic nuclei
present in the air
Hygroscopic nuclei may
consist of dust, smoke,
soot, salt, or other small
airborne particles
If the proper type/size of
airborne particles are not
present, condensation
may not occur or will be
retarded
5. Precipitation
When condensation does
occur, the tiny droplets are
formed in updrafts and are
easily suspended as a cloud
Precipitation requires
larger drops to form
Two processes are thought
to be responsible for the
formation of drops large
enough to fall
Coalescence
The Bergeron process
6. Coalescence – the formation of
larger drops by the collision of
droplets
Coalescence
7. The Bergeron Process
The Bergeron process involves
three essential components
Ice crystals in the upper
portion of the cloud
Supper cooled vapor in
the lower portion of the
cloud
Mixing or agitation brings
the ice crystals in contact
with the supper cooled
vapor
9. Hailstones
If the convection cells in the
thunderstorms are powerful enough,
hailstones can become quite large
10. Air Masses
Air mass – a large body of air that
takes on physical characteristics that
distinguish it from the surrounding air
The main physical characteristics the
distinguish an air mass are
temperature and moisture content
11. Storms
Storm – an atmospheric disturbance that may
develop within a single air mass or may
develop along the frontal boundary of air
masses
There re different types of storms.
rainstorms, thunderstorms, ice storms,
snowstorms, and tornadoes
12. Lightning and Thunder
A lightning flash travels at the speed
of 300,000 km/s (speed of light)
Thunder is a sound and only travels at
a speed of approximately 1/3 km/s
(1/5 mi/s)
13. Atmospheric Pollution
Pollution – any atypical contributions
to the environment resulting from the
activities of humans
Air pollution is primarily the result of
products of combustion and industrial
processes that are released into the
atmosphere
Releasing waste gases and
particulates into the atmosphere has
long been practiced
14. Air Pollution Sources
The major source of air
pollution is due to the
combustion of fossil
fuels – coal, oil, and
gas
Increased amounts of
CO2 in the atmosphere
lead to increased
acidity
Pollution and increased
acidity of the rain
results in statues and
other structures
undergoing
increased/accelerated
corrosion
15. Pollution and Climate
It is generally accepted by most
scientists that the global climate is
also being affected by atmospheric
pollution
CO2 and other “greenhouse gases,”
particulate emissions, and the resulting
global cloud cover all affect the Earth’s also
Scientists are trying to understand climate
changes by using various models
Climate models give scientists the
opportunity to compare theories and use
historical data to study the interrelationships
between the Earth’s atmosphere and other
factors
.