Questions on ozone and nitrogen oxides

Are you able to answer to the following questions?

Before you answer, you should have read the Research and Fundamentals texts of this edition. Discuss also the page "Example - Ozone and NOx"
 

1) Ozone diurnal pattern

a) Which differences do you see about in the concentration changes of ozone between a station in or next to a town and a station in the forest? Describe in 4-8 sentences!

b) Nitrate radicals (NO₃) are stable in the night. They form if ozone reacts with NO₂. Which consequences has this for the diurnal cycle of ozone concentrations in urban areas? What happens in the forest?

2) Ozone formation and transport

a) What are typical concentrations [µg/m3] or mixing ratios [ppb] for background ozone?

b) Before catalytic converters were invented, ozone peak values were higher on sunny days. Why?

c) The ozone values at the forest station are higher than the values in or next to a town. Can you explain why?

3) Particle filters

a) If more NO₂ is emitted by cars with particle filters, what are the consequences?

b) Can the consequences be better observed in the city centre or in the suburbs?

c) Which problems do experts see when even stricter guidelines come into force for all emissions of cars in Europe (nitrogen oxides, particles, carbon dioxide)? Are the present technologies sufficient in order to guarantee that pollutants in urban areas do not exceed the envisioned limit values?

Further material:

The following links can be helpful in order to undestand more about ozone formation.

Text ozone smog on ESPERE
http://www.atmosphere.mpg.de/enid/23c.html

Worksheets on ESPERE
http://www.atmosphere.mpg.de/enid/3z4.html

http://www.atmosphere.mpg.de/enid/3z5.html