Problem Session 6 [11/17/96]

In PS6 you will add a reduced set of nitrogen reactions to your model. This will result in additions to the Ox and HOx time-dependent equations, additions to the partitioning equations for O3 and O and HO and HO2, two new time-dependent equations for NOx and HNO3, and a new partitioning equation for NO and NO2.

Use the specified constant levels of NOy given in PS5 for NOy = NOx + HNO3 and the specified constant levels of CO given below. You should then add reactions R16 - R21, R30 and R32 to both the time-dependent and the partitioning equations, as required. You solve for the steady-state concentrations of O3, O, OH, HO2, H2O2, NO, NO2, and HNO3 for 50 - 20km [the stratospheric levels].

 z   CO (ppbv)

50   36
45   18
40   13
35   12
30   11
25   12
20   18
15   37
10   56
 5   68
 0  100

Having successfully established the correct steady-state values for the stratosphere:

1. Calculate the chemical destruction of Ox by the Chapman loss reaction/s, the HOx species and NOx for 50km, 40km, 30km and 20km, and identify the dominant destruction reaction at each level;
2. Double your level of H2O in the stratosphere and determine the resulting impact on O3;
3. Identify the reactions responsible for the observed change in O3 and explain the chemical mechanism.

PS6 will be due before you leave for Thanksgiving. Lori and I will decide about C chemistry before next week.