HR: 11:05h
AN: A42A-04    [Abstracts]
TI: HOx Chemistry and Ozone Production During INTEX-B
AU: * Ren, X
EM: xren@rsmas.miami.edu
AF: Penn State University, 503 Walker Building, University Park, PA 16801, United States
AU: * Ren, X
EM: xren@rsmas.miami.edu
AF: University of Miami, 4600 Rickenbaker Causeway RSMAS/MAC, Miami, FL 33149, United States
AU: Mao, J
AF: Penn State University, 503 Walker Building, University Park, PA 16801, United States
AU: Chen, Z
AF: Penn State University, 503 Walker Building, University Park, PA 16801, United States
AU: Brune, W
AF: Penn State University, 503 Walker Building, University Park, PA 16801, United States
AU: Olson, J
AF: NASA Langley Research Center, Mail Stop 483, Hampton, VA 23681, United States
AU: Crawford, J
AF: NASA Langley Research Center, Mail Stop 483, Hampton, VA 23681, United States
AU: Chen, G
AF: NASA Langley Research Center, Mail Stop 483, Hampton, VA 23681, United States
AB: Measurements of OH and HO₂ (collectively called HO_x) were made with the Airborne Tropospheric Hydrogen Oxides Sensor (ATHOS) as part of a much larger measurement suit from the NASA DC-8 aircraft during INTEX-B in spring 2006. This mission, which was conducted mainly over South United State and Mexico (Phase- A) and West Pacific Ocean (Phase-B), was an excellent test of oxidation chemistry in pollution plumes and clean air throughout the troposphere. Measured HO_x are compared with the calculations from a box model constrained to other in-situ measurements of long-lived chemicals. On average, both the measured OH and HO₂ agree well with the calculations within 15%, which is similar to the results during INTEX-A, another aircraft mission conducted over the continental of the United States, except above 8 km where the model significantly under-predicted HO₂ during INTEX-A. The main HO_x production was the O(¹D)+H₂O reaction and main HOx loss was the HO₂+HO₂ and HO₂+RO₂ reactions. During Phase-A, there was a net O₃ production rate (0.1-1 ppb/hr) below 4 km, while during Phase-B a slight net O₃ loss rate (0.1-0 ppb/hr) below 7 km and a slight net O3 production rate (0-0.1 ppb/hr) above 7 km were observed. HO_x behavior under different conditions will be discussed.
DE: 0340 Middle atmosphere: composition and chemistry
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 0365 Troposphere: composition and chemistry
DE: 0368 Troposphere: constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting