Figure 2-1: Net ozone production (24-hr average) as a function of NOx
in the upper troposphere (adapted from Jaegl� et al., 1998). During the NASA-sponsored
SUCCESS campaign (April-May 1996), simultaneous measurements of HO2 and NO
were obtained from the NASA DC-8 aircraft. These observations define the rate
of ozone production via the chemistry outlined in Section 2.1.2.1. Also shown
in this figure are three calculations for average tropospheric conditions
experienced above 11 km during SUCCESS. Case 0 illustrates the production
rate expected if the only primary source of HOx is the reaction of O1D with
H2O and CH4. Case 1 is the rate calculated by assuming acetone is present
at 510 ppbv, consistent with recent airborne measurements (Singh et al., 1995;
Arnold et al., 1997). Case 2 assumes that a convective source of peroxides
and formaldehyde provides additional HOx production. These non-traditional
HOx sources dramatically increase the ozone production rate in the dry (<100
ppmv H2O) upper troposphere.
