Thermal inversion:-
Thermal energy is the exhertion of power that is created by heat, or the increase in temperature. The Sun is a source of thermal energy. Hot water turned to steam is another source.
whenever in nature the heat gets over follow then in that case thermal inversion takes place it is very dangerous to our environment.
Thermal Inversions.
In the normal situation, the temperature decreases as you go up in altitude in the
troposphere. The rate of decrease varies, but an accepted average value is 6.5 degrees
Celsius per 1000 meters (this is called the normal lapse rate). That is, if you start at sea
level and go up (say, in a balloon) 1000 meters in the atmosphere, you can expect that
the temperature of the surrounding air will drop an average of 6.5 degrees Celsius. Go
up another 1000 meters (one kilometer), and the temperature will drop another 6.5
degrees (that is, it will be 13 degrees colder than it was when you started at sea level). If
you are measuring in feet and Fahrenheit degrees, this translates to a drop of about 3.6
degrees F per 1000 feet.
Photochemical Smog
What follows is a brief description of photochemical smog formation, from a nonchemist.
For those who want to pursue this topic, there are also some links to follow
for more information.
Photochemical smog is brown smog, the gray-brown haze that fills the air in many
cities. It is especially a problem in warm, sunny regions where there are lots of cars
burning gasoline. Researchers in the 1940's and 1950's in Los Angeles noticed that the
kinds of pollutants in the air varied over the course of the day. Some pollutants
increased in the morning, as people started driving their cars. Other pollutants,
including the visible, brown smoggy haze, were most common in the middle of the day.
The mix of pollutants changed again in the late afternoon and evening. It became
apparent that the chemical reactions among the various pollutants were related to
sunlight. Smog is worse in Los Angeles--and everywhere--in the summer, because the
light energy from the sun moves some of the reactions along.
To form photochemical smog, three main ingredients are needed: nitrogen oxides
(NOx), hydrocarbons, and energy from the sun in the form of ultraviolet light (UV).
The first thing that starts the chain of events is that people start driving in the
morning. As gasoline is burned, nitrogen (N2) in the atmosphere is also burned, or
oxidized, forming nitric oxide (NO)
N2 + O2=2NO
Hydrocarbons and carbon monoxide (CO) will also be emitted by cars. Hydrocarbons
are volatile organic compounds that may include acetaldehyde, formaldehyde, ethylene,
and many other compounds.
In the air, nitric oxide combines with molecular oxygen to form nitrogen dioxide within a
few hours.
2NO + O2--------->2NO2
Nitrogen dioxide absorbs light energy and splits to form nitric oxide and atomic oxygen:
NO2-->NO + O
Then, in sunlight, the atomic oxygen combines with oxygen gas to form ozone (O3):
O+ O2--->O3
If no other factors are involved, ozone and nitric oxide then react to form nitrogen
dioxide and oxygen gas.
O3 + NO<------>NO2 + O2
Thermal energy is the exhertion of power that is created by heat, or the increase in temperature. The Sun is a source of thermal energy. Hot water turned to steam is another source.
whenever in nature the heat gets over follow then in that case thermal inversion takes place it is very dangerous to our environment.
Thermal Inversions.
In the normal situation, the temperature decreases as you go up in altitude in the
troposphere. The rate of decrease varies, but an accepted average value is 6.5 degrees
Celsius per 1000 meters (this is called the normal lapse rate). That is, if you start at sea
level and go up (say, in a balloon) 1000 meters in the atmosphere, you can expect that
the temperature of the surrounding air will drop an average of 6.5 degrees Celsius. Go
up another 1000 meters (one kilometer), and the temperature will drop another 6.5
degrees (that is, it will be 13 degrees colder than it was when you started at sea level). If
you are measuring in feet and Fahrenheit degrees, this translates to a drop of about 3.6
degrees F per 1000 feet.
Photochemical Smog
What follows is a brief description of photochemical smog formation, from a nonchemist.
For those who want to pursue this topic, there are also some links to follow
for more information.
Photochemical smog is brown smog, the gray-brown haze that fills the air in many
cities. It is especially a problem in warm, sunny regions where there are lots of cars
burning gasoline. Researchers in the 1940's and 1950's in Los Angeles noticed that the
kinds of pollutants in the air varied over the course of the day. Some pollutants
increased in the morning, as people started driving their cars. Other pollutants,
including the visible, brown smoggy haze, were most common in the middle of the day.
The mix of pollutants changed again in the late afternoon and evening. It became
apparent that the chemical reactions among the various pollutants were related to
sunlight. Smog is worse in Los Angeles--and everywhere--in the summer, because the
light energy from the sun moves some of the reactions along.
To form photochemical smog, three main ingredients are needed: nitrogen oxides
(NOx), hydrocarbons, and energy from the sun in the form of ultraviolet light (UV).
The first thing that starts the chain of events is that people start driving in the
morning. As gasoline is burned, nitrogen (N2) in the atmosphere is also burned, or
oxidized, forming nitric oxide (NO)
N2 + O2=2NO
Hydrocarbons and carbon monoxide (CO) will also be emitted by cars. Hydrocarbons
are volatile organic compounds that may include acetaldehyde, formaldehyde, ethylene,
and many other compounds.
In the air, nitric oxide combines with molecular oxygen to form nitrogen dioxide within a
few hours.
2NO + O2--------->2NO2
Nitrogen dioxide absorbs light energy and splits to form nitric oxide and atomic oxygen:
NO2-->NO + O
Then, in sunlight, the atomic oxygen combines with oxygen gas to form ozone (O3):
O+ O2--->O3
If no other factors are involved, ozone and nitric oxide then react to form nitrogen
dioxide and oxygen gas.
O3 + NO<------>NO2 + O2
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