HR: 11:52h
AN: A22A-07    [Abstracts]
TI: Convective Vertical Redistribution of Trace Gases in the Tropics: A First Look at Chemical Tracer and Meteorological Measurements from the NASA DC-8 during TC4
AU: * Avery, M A
EM: Melody.A.Avery@nasa.gov
AF: NASA Langley Research Center, Langley Blvd, Hampton, VA 23681, United States
AU: Glenn, D
EM: Glenn.S.Diskin@nasa.gov
AF: NASA Langley Research Center, Langley Blvd, Hampton, VA 23681, United States
AU: Sachse, G
EM: Glen.W.Sachse@nasa.gov
AF: National Institute for Aerospace, Research Blvd, Hampton, VA 23681, United States
AU: Podolske, J
AF: NASA Ames Research Center, Moffett Field, Moffett Field, CA 94035, United States
AU: Bui, P
AF: NASA Ames Research Center, Moffett Field, Moffett Field, CA 94035, United States
AU: Pfister, L
AF: NASA Ames Research Center, Moffett Field, Moffett Field, CA 94035, United States
AU: Korn, E
AF: National Atmospheric Research Center, PO Box 3000, Boulder, CO 80307, United States
AU: Cohen, R
AF: University of California at Berkeley, College Road, Berkeley, CA 94720, United States
AU: Wooldridge, P
AF: University of California at Berkeley, College Road, Berkeley, CA 94720, United States
AU: Perring, A
AF: University of California at Berkeley, College Road, Berkeley, CA 94720, United States
AU: Bertram, T
AF: University of California at Berkeley, College Road, Berkeley, CA 94720, United States
AB: Fast, accurate in situ chemical tracer and meteorological measurements were made from the NASA DC-8 and from dropsondes during the Tropical Composition, Clouds and Climate Coupling field experiment in the ITCZ region near Costa Rica. These measurements, from the Eastern Pacific and Western Caribbean during summer, show significantly higher mixing ratios of ozone measured throughout the troposphere than do ozone observations from the ITCZ region in the Central Pacific during the PEM Tropics-B field mission during the spring of 1999. Tracer correlations are chaotic when analyzed at 1 second (200 m) resolution, indicating vertical transport and extensive mixing of air by the vigorous convection in this region, and it appears that aged pollution from higher latitudes in the Northern Hemisphere has been well-mixed into the clean Tropical tropospheric background. Given the availability of both hydrocarbons and reactive nitrogen from either this source or from lightning, some of the ozone observed may have been produced in situ, photochemically. Wind and water vapor measurements from sondes launched from the DC-8 provide the means to separate the aircraft data vertically in a dynamically sensitive way. Measurement probability distributions are then used in addition to the tracer correlations and wind measurements to deduce the vertical distribution of primary and ancillary air "types" or source regions in the well-mixed Tropical troposphere. Using these results and a simple mass-balance approach, we estimate the fraction of marine boundary layer air that has been mixed into the upper troposphere, just below the Tropical Transition Layer, and compare to recent mid-latitude estimates from Bertram et. al., (Science, 2007). Finally, we offer some preliminary ideas about why ozone mixing ratios measured near the ITCZ during PEM Tropics-B and TC4 differ so greatly.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0340 Middle atmosphere: composition and chemistry
DE: 0350 Pressure, density, and temperature
DE: 0365 Troposphere: composition and chemistry
DE: 0368 Troposphere: constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting