HR: 0800h
AN: A21E-0767    [Abstracts]
TI: The influence of convection on the water vapor and isotopic composition of the upper TTL and tropical stratosphere
AU: * Sayres, D S
EM: sayres@huarp.harvard.edu
AF: Harvard University School of Engineering and Applied Sciences, 12 Oxford Street, Cambridge, MA 02138, United States
AU: St. Clair, J M
EM: jstclair@huarp.harvard.edu
AF: Harvard University School of Engineering and Applied Sciences, 12 Oxford Street, Cambridge, MA 02138, United States
AU: Hanisco, T F
EM: hanisco@huarp.harvard.edu
AF: Harvard University School of Engineering and Applied Sciences, 12 Oxford Street, Cambridge, MA 02138, United States
AU: O'Brien, A
EM: obrien@huarp.harvard.edu
AF: Harvard University School of Engineering and Applied Sciences, 12 Oxford Street, Cambridge, MA 02138, United States
AU: Moyer, E J
EM: moyer@huarp.harvard.edu
AF: Harvard University School of Engineering and Applied Sciences, 12 Oxford Street, Cambridge, MA 02138, United States
AU: Smith, J B
EM: jxsmith@huarp.harvard.edu
AF: Harvard University School of Engineering and Applied Sciences, 12 Oxford Street, Cambridge, MA 02138, United States
AU: Weinstock, E M
EM: weinstock@huarp.harvard.edu
AF: Harvard University School of Engineering and Applied Sciences, 12 Oxford Street, Cambridge, MA 02138, United States
AU: Anderson, J G
EM: anderson@huarp.harvard.edu
AF: Harvard University School of Engineering and Applied Sciences, 12 Oxford Street, Cambridge, MA 02138, United States
AU: Pfister, L
EM: Leonhard.Pfister-1@nasa.gov
AF: NASA Ames Research Center, Mail Stop 204-2, Moffett Field, CA 94035, United States
AU: Legg, M
EM: mlegg@mail.arc.nasa.gov
AF: BAERI, 560 Third St. West, Sonoma, CA 95476, United States
AB: We use recent in-situ observations of tropical H2O and HDO from the NASA WB-57 aircraft, coupled with a back trajectory model of convective influence, to study the effects of convection on air ascending into the tropical stratosphere. Data are presented from both the CR-AVE and TC4 campaigns to show differences in the convective influence between the wintertime and summertime. We measure heavy isotopic compositions of stratospheric water vapor as compared to the expected value from Rayleigh distillation. We also see surprisingly little isotopic gradient between the regions and seasons sampled, even though water vapor shows the expected seasonal and altitude dependence. We examine the possibility that stratospheric isotopic homogeneity is indicative of significant exchange between the midlatitudes and tropical upper troposphere. Back-trajectories suggest that a large fraction of sampled tropical air has recently traveled through latitudes higher than the subtropical jet.
DE: 3314 Convective processes
DE: 3362 Stratosphere/troposphere interactions
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting