Question

1) Carbon dioxide and water combined typically make up 1-3% of our atmosphere, and yet, we are constantly monitoring the atmospheric content of CO2 and H2O. Why? Explain why they vary from hour to hour and why they are such important gases in our atmosphere despite the fact that they are not the top three gases in our atmosphere.

(2) With one exception, the relative concentrations of atmospheric gases do not change with height. Indicate this exception, its concentration patterns, and reasons why this is the case.

(3) The atmosphere is in constant motion. Why? What is the general pattern of airflow? Explain why there is this general pattern of airflow and why atmospheric gases don’t simply flow into outer space.

(4) The composition of the Earth’s atmosphere has changed in the past 200 years. What are/were the major changes in our atmospheric composition?

(5) Name the top ten air pollutants we presently regulate. Is there a common source for these top ten pollutants? If so, what is it? What percentage of our atmospheric gases do these top ten regulated gases make up?

(5) Name the top ten air pollutants we presently regulate. Is there a common source for these top ten pollutants? If so, what is it? What percentage of our atmospheric gases do these top ten regulated gases make up?

(6) Identify the sinks for the following molecules and the transformation of the molecules due to the sink.

Molecule

Sink for molecule

Form of molecule after sink used

SO2

CO2

O3

NO2

(7) Identify two factors that affect the lifetime of pollutants in the atmosphere, and explain how these two factors affect pollutant lifetime. Why should you be aware of it

(8) When fossil fuel is burned, many different types of carbon-based molecules can be emitted. Of all carbon-based emissions, carbon dioxide is the best-case scenario given what will occur to the other carbon-based emissions. Explain why you agree or disagree with the previous statement and the consequence of this fact.

(9) The CAA dealt with both stratospheric and tropospheric ozone issues. Explain what emissions the CAA limited to address these two issues. It would be helpful to fill in the following table:

Emissions in CAA which addressed stratospheric ozone issue (10) A colleague comments to you that the ozone hole must be getting worse since we are having so many ozone alert days. How would you gently correct this misconception of your colleague in relating ozone alert days with the ozone hole?

Emissions in CAA which addressed tropospheric ozone issue

Answer 1

1) These are the most important green house gases in the earth's atmosphere (most abundant). They are the primary reason for absrobption of heat from sun. So even a small increase in concentration of CO2 or water vapour can alter the temperature of earth atomosphere and hence can imbalance the temperature.

The concentration of water vapour vaires with the temperature of atmosphere

and the concentration of CO2 varies due to anthropongenic activities and plant density

2) OZone : The concentration of ozone increases with the height.

Its maximum concentration lies in between the strtosphere. after this the concentration starts decreasing again.

The concentration varies due to following reactions

O2 ---> O + O ( in presence of light)

O + O2 -> Ozone (comibnation of oxygen atom with oxygen molecule)

3) The earth undergoes unequal or imbalanced heating due to which the air moves according to difference in temperature and pressure so we call it to be in constant motion.

The movement of air is from high pressure zone to low pressure zone.

4) any molecule can escape the earth atomosphere to space it it has velcity higher then escap velocity.

The different reasons why the molecules do not escape are

a) they do not have suffecient velocity ( due to backward pull of gravity of earth)

b) lets say they have suffecient velecoty, but they collide with the molecules which come in their path which decrease their speed and change their direction of motion

c) small molecules may get escape velocity but due to collision they generally do not cross the limit, however some hdyrogen molecules do escape from earth atmosphere

5) we can enlist the pollutants as : sulphur oxides , Nitrogen oxides , volatile matter (Methane etc) , Carbon monoxide, CFC , Ammonia , free radicals , radioactive elements as pollutant, particulates , some metals.

Industries are the primary source

Anthorpogenic activities

6) SO2 : sink is ocean : Oxidized to SO4-2 etc

b) CO2: oceans, plants and microbes : they convert it to glucose etc

c) NO2 : sink is ocean , converted to nitric acid and rained down

d) ozone:uptake by plants, also in atmosphere get decompsed in presence of light (O2)

7) The life time of pollutant depends upon

a) the ability to react with hydroxide ion (lesser the reactivity more the life span)

b) photocatalytic decomposition : it also decrease the lifetime

8) The burning of fuel convert all hydrocarbons into CO2 , in presence of sufficient supply of oxygen, however in less supply of oxygne they give carbon monoxide.

9)Emissions in CAA which addressed stratospheric ozone issue: ozone depletion emissions

b) Emissions in CAA which addressed tropospheric ozone issue: CO2 emission