HR: 10:40h
AN: A22A-02 [Abstracts]
TI: Observations of the isotopic composition of vapor and condensed water in the tropical tropopause layer
AU: * Hanisco, T F
EM: hanisco@huarp.harvard.edu
AF: Harvard University, Department of Chemistry, Cambridge, MA 02138, United States
AU: Sayres, D S
EM: sayres@huarp.harvard.edu
AF: Harvard University, Department of Chemistry, Cambridge, MA 02138, United States
AU: St.Clair, J M
EM: st.clair@huarp.harvard.edu
AF: Harvard University, Department of Chemistry, Cambridge, MA 02138, United States
AU: O'Brien, A S
EM: obrien@huarp.harvard.edu
AF: Harvard University, Department of Chemistry, Cambridge, MA 02138, United States
AU: Smith, J B
EM: smith@huarp.harvard.edu
AF: Harvard University, Department of Chemistry, Cambridge, MA 02138, United States
AU: Weinstock, E M
EM: weinstock@huarp.harvard.edu
AF: Harvard University, Department of Chemistry, Cambridge, MA 02138, United States
AU: Anderson, J G
EM: anderson@huarp.harvard.edu
AF: Harvard University, Department of Chemistry, Cambridge, MA 02138, United States
AB:
We present the first simultaneous measurements of the isotopic composition of total water (vapor + condensed)
and water vapor in the upper troposphere and lower stratosphere. The isotopic composition of the condensed
phase is derived from the difference between the total and vapor phase measurements of the Harvard Hoxotope
and ICOS instruments flown on the NASA WB-57 during TC4. These measurements in the tropical tropopause
layer (TTL) and in mid-latitudes are used to identify mechanisms for water transport into the TTL and lower
stratosphere. Observations within clouds over the Panama Bight region show little difference between the vapor
and condensed phase isotope ratios. The uniformity of isotope ratio is consistent with equilibrium
thermodynamics and rapid exchange of water with the surrounding airmass. Observations of thin outflow clouds
or streamers indicate a higher condensed phase ratio, consistent with transport of water from lower altitudes.
Further observations of outflow from deep convection directly into the overworld stratosphere extend the
observational database that supports a mechanism for adding water to the stratosphere that bypasses the
tropical tropopause.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0320 Cloud physics and chemistry
DE: 0341 Middle atmosphere: constituent transport and chemistry (3334)
DE: 0368 Troposphere: constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting