ENVI 1011 Environmental Science III Global Atmosphere Assignment Due Date: 29th April 2011

Name: Slavica Kandic
ID: s3185267 Station: Museum

Question 1:

Data is supplied for an EPA monitoring station, showing changes in levels of monitored pollutants during a day. You can get a copy of the data for your assigned station from s:\ug\ENVI1011 or the learning hub site for ENVI 1011.

a) Describe the location and characteristics of the station b) Display the data on a suitable graph to show the relative changes in each pollutant during the day c) For each pollutant monitored, indicate …show more content…

Health effects caused by Sulphur Dioxide include irritation of the bronchial mucosa, increased incidence of lung disease and respiratory problems.
Measurement method is applied through Pulsed Fluorescence. It is a system where chamber filled with the sample is focused by filtered UV light.at this excessive energy state, SO2 molecule becomes excited,and also are able to emit A radiation for the detection by a light –sensitive photomultiplier tube which transfer the signal.(EPA)

d) Model presented in the graph corresponds to Photochemical Smog Model.As it seen from the graph, Nitric Oxide reaches the highest level at 8 am due to highest vehicle emmision.Its concentration is also high as free radicals did not converted the NO emission into NO2.Therefore that higher concentration of NO2 are reached at noon, due to reaction of NO with peroxy radicals. At the time (noon)when NO and NO2 achieve equilibrium, ozone begins to form. From that poin, NO2 content starts to decrease due to sink reaction where NO2 reacts with peroxy radical to form nitric acid:

NO2+HO+M → HNO3+M

Nitrogen dioxide absorbs sunlight splitting and form NO and O.

NO2→NO+O

Then elementary oxygen react with oxygen atom to form ozone (O3). Ozone concentration appears highest at 3 pm when its concentration starts to decrease until 9pm when ozone in