HR: 1340h
AN: A13C-1361    [Abstracts]
TI: In situ water isotope measurements aboard the WB-57 from 2005 to 2007: searching for seasonal and latitudinal trends
AU: * St. Clair, J M
EM: jstclair@huarp.harvard.edu
AU: Hanisco, T F
EM: tfh@huarp.harvard.edu
AU: Sayres, D S
EM: sayres@fas.harvard.edu
AU: O'Brien, A S
EM: aobrien@fas.harvard.edu
AU: Moyer, E J
EM: moyer@huarp.harvard.edu
AU: Anderson, J G
EM: anderson@huarp.harvard.edu
AB: We present new TTL and lower stratospheric in situ observations of water isotopes obtained on the NASA WB-57 in the summer and winter in both Houston and Costa Rica. The seasonal and latitudinal spread of data from AVE-WIIF, CR-AVE, and TC4 allow for an investigation of winter-to-summer and latitudinal variability in δD using a self-consistent, exclusively in situ data set. The relative abundance of the hydrogen isotopes of water, H2O and HDO, is a sensitive indicator of the condensation history of an air mass in the upper troposphere and lower stratosphere. Measurements of δD, then, can lend insight to understanding how, where, and when water vapor and air in general are transported into the stratosphere. Traditional thought maintains that stratospheric water enters in the tropics, though the transport mechanism and longitudinal location has always been subject to debate. Numerous recent measurements, however, show evidence of a convective source of overworld stratospheric water vapor in the mid-latitudes, though the relative influence of the source has yet to be determined. Comparison of mid-latitude profiles to those from the tropics, as well as to prior remote and in situ observations, provides a context for these observations.
DE: 0341 Middle atmosphere: constituent transport and chemistry (3334)
DE: 3314 Convective processes
DE: 3362 Stratosphere/troposphere interactions
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting