HR: 11:05h
AN: A52A-04 INVITED    [Abstracts]
TI: Do tropospheric OH measurements agree with models?
AU: * Brune, W H
EM: brune@ems.psu.edu
AF: Pennsylvania State University, Department of Meteorology, University Park, PA 16802,
AU: Emmons, L K
AF: NCAR, Atmospheric Chemistry Division, Boulder, CO 80301,
AU: Olson, J R
AF: NASA Langley Research Center, 21 Langley Research Center, Hampton, VA 23681,
AU: Chen, G
AF: NASA Langley Research Center, 21 Langley Research Center, Hampton, VA 23681,
AU: Crawford, J H
AF: NASA Langley Research Center, 21 Langley Research Center, Hampton, VA 23681,
AU: Pierce, R B
AF: NOAA, CIMSS ASPB, Madison, WI 53706,
AU: Jacob, D J
AF: Harvard University, DEPS, Cambridge, MA 02138,
AU: Carmichael, G R
AF: University of Iowa, Department of Chemical and Biochemical Engineering, Iowa City, IA 52242,
AB: In situ measurements of OH from aircraft provide insight into the global mean OH that is calculated by models and tracer lifetimes. Although it is difficult to compare in situ aircraft OH measurements with the OH calculated in global models, it is not impossible. One method is to compare measured OH to OH calculated by a box model that is constrained by simultaneous in situ measurements of everything that affects OH. The chemical mechanisms used in box models and chemical transport models can then be compared. Another is to compare the measured OH to OH obtained by "flying" the aircraft through the box model. A recent recalibration of our in situ OH measurements has brought measured OH from three field studies into general agreement with OH calculated with a box model. The agreement is best in clean air and degrades as air quality degrades. Agreement between measurements and chemical transport models (CTM) is generally less good, as would be expected, since errors in the CTM transport and emissions also affect calculated OH. These comparisons and their implications for global OH will be discussed.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0365 Troposphere: composition and chemistry
DE: 0368 Troposphere: constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting