HR: 09:00h
AN: A41C-04    [Abstracts]
TI: Preliminary observations of methylhydroperoxide (CH$_{3}$OOH) and formaldehyde (CH$_{2}$O) in fresh convective outflow during INTEX-NA, summer 2004.
AU: * Snow, J A
EM: julie.snow@sru.edu
AF: Department of Geography, Geology, and the Environment, Slippery Rock University, Slippery Rock, PA 16057 United States
AU: Heikes, B G
EM: bheikes@gso.uri.edu
AF: Center for Atmospheric Chemistry, Grad. School of Oceanography, Univ. of Rhode Island, South Ferry Rd., Narragansett, RI 02882 United States
AU: O'Sullivan, D W
EM: osulliva@usna.edu
AF: Department of Chemistry, United States Naval Academy 572 Holloway Rd., Annapolis, MD 21402 United States
AU: Shen, H
EM: hshen@gso.uri.edu
AF: Center for Atmospheric Chemistry, Grad. School of Oceanography, Univ. of Rhode Island, South Ferry Rd., Narragansett, RI 02882 United States
AU: Fried, A
EM: fried@ucar.edu
AF: National Center for Atmospheric Research, Atmospheric Technology and Chemistry Divisions, 3450 Mitchell Lane, Boulder, CO 80301 United States
AU: Walega, J
EM: walega@ucar.edu
AF: National Center for Atmospheric Research, Atmospheric Technology and Chemistry Divisions, 3450 Mitchell Lane, Boulder, CO 80301 United States
AU: Crounse, J D
EM: crounjd@caltech.edu
AF: California Institute of Technology, MC 150-21 1200 E. California Blvd., Pasadena, CA 91125 United States
AU: Wennberg, P O
EM: wennberg@gps.caltech.edu
AF: California Institute of Technology, MC 150-21 1200 E. California Blvd., Pasadena, CA 91125 United States
AU: Kwan, A J
EM: kwan@caltech.edu
AF: California Institute of Technology, MC 150-21 1200 E. California Blvd., Pasadena, CA 91125 United States
AU: Crawford, J H
EM: j.h.crawford@larc.nasa.gov
AF: NASA Langley Research Center, 21 Langley Blvd., Hampton, VA 23681-0001 United States
AB: Studies have suggested that CH$_{3}$OOH and CH$_{2}$O are significant sources of HO$_{x}$, particularly in the upper atmosphere where the reactions of O$^{1}$D and H$_{2}$O do not dominate HO$_{x}$ production. Convection provides a transport mechanism for these HO$_{x}$ precursors to reach the upper atmosphere. In this study, we use the ratio of hydrogen peroxide (H$_{2}$O$_{2}$) to CH$_{3}$OOH, which can serve as an indication of fresh convective outflow given the difference in solubility of the two species, to identify convectively influenced air masses. Observations of H$_{2}$O$_{2}$, CH$_{3}$OOH, and CH$_{2}$O were made by two independent instruments on board the NASA DC-8 during the INTEX-NA science campaign (summer 2004). Preliminary results from INTEX-NA indicate the ratio of H$_{2}$O$_{2}$/CH$_{3}$OOH was 2-4 in the continental boundary layer while the ratio measured in fresh continental convective outflow was $\sim$1. Using this and other species ratios, we will examine fresh continental convective outflow over North America and ask the question, Do elevated CH$_{3}$OOH and CH$_{2}$O reflect simply the direct injection of these compounds or their precursors? Observations from the INTEX-NA campaign will be compared to results from the TOPSE program (winter/spring 2000), which showed CH$_{3}$OOH was not a significant source of HO$_{x}$, while CH$_{2}$O was a dominant source of HO$_{x}$ in the upper troposphere at higher latitudes.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0365 Troposphere--composition and chemistry
DE: 0368 Troposphere--constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting