[Sensitivity and uncertainty analysis of atmospheric photochemistry models. Progress report, September 30, 1995--September 22, 1996] Page: 4 of 6
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JUN 24 '96 05:2PM MOLECULAR PHYSICS330
We explored various methods to freeze the concentrations in our box photograph and
sealed on a systematic correction technique that minimizes this external sensitivity. In most cases
P-L terms within a family largely cancel, with pairs such as NO/NO2 and CI/CIO dominating in
opposite directions. Thus we assign each family's summed net P - L to that species with the
largest individual P - L in that diction and achieve negligible drift over long integration times with
minimal sensitivity to the P - L rate term. In most cases ozone, HOx, and long-lived species P - L
terms are also included, and at lower altitudes separate P - L terms for nitric and hydrochloric acids
are needed. We are still exploring the interpretation of this treatment vis-i-vis the full 2-D model.
We have largely completed our survey sensitivity computations on selected boxes from the
LLNL 2-D model and expect to conclude in the next two months; somne work has been done
successfully under all representative conditions. Sensitivity coefficients were computed at 4-5 lan
intervals from below the tropopause to 50 km for the following latitudes and seasons: 2N March,
32N March, 47N February, 47N August, 62N February, 62N August, and 82S October. A
manuscript is in preparation for the Journal of Geophysical Research describing this work, and
various aspects of this work have been discussed this past year in two presentations at the NASA
Atmospheric Effects of Aviation Program meeting in Virginia Beach and in a talk and poster at the
American Geophysical Union meeting in San Francisco.
Some representatve results using a few key reactions and selected boxes are shown in
Table 1 to illustrate various trends. The prominence of ozone production and little other controlling
chemisty in the equatorial lower stratosphere and the successive rise of NOx and C1Ox catalytic
destruction as altitude and latitude increase are examples. The seasonality of northern ozone
removal is also illustrated in the sensitivities.
TABLE 1. OZONE SENSITIVITY COEFFICIENTS
Latitude/Season 2N 2N 2N 2N 2N 32N 47N 62N 62N
Mar Mar Mar Mar Mar Mar Feb Feb Aug
Altitude 20 25 30 35 40 26 25 25 25
02+hv a 0+0 0.87 0.85 0.54 0.44 0.49 0.61 0.13 0.17 0.46
0+02+M- 03+M 0.014 0.14 0.38 0.39 0.40 0.26 0.42 0.79 0.53
03+hv = 0+02 -0.013 -0.13 -0.31 -0.24 -0.15 -0.25 -0.40 -0.71 -0.50
O+NO2 = NO+02 -0.008 -0.067 -0.22 -0.24 -0.29 -0.15 -0.22 -0.64 -0.41
NO+03 = N02+02 -0.025 -0.031 -0.17 -0.22 -0.21 -0.08 -0.10 -0.11 -0.15
OH+63 = H02+02 -0.031 -0.063 -0.024 0.006 0.016 -0.06 -0.08 -0.06 -0.08
HO2+03 - 20H+02 -0.036 -0.068 -0.027 -0.007 -0.002 -0408 -0.10 -0.04 -0.08
0+00 C+02 -0.001 -0.032 -0.062 -0.052 -0.079 -0.05 -0.10 -0.05 -0.04
C6+3= C010+02 -0.011 -0.010 -0.081 -0.087 -0.103 -0.07 -0.08 -0.01 -0.032
P.9
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[Sensitivity and uncertainty analysis of atmospheric photochemistry models. Progress report, September 30, 1995--September 22, 1996], report, November 1, 1996; Menlo Park, California. (https://digital.library.unt.edu/ark:/67531/metadc687894/m1/4/: accessed April 19, 2024), University of North Texas Libraries, UNT Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.