HR: 11:38h
AN: A22A-06    [Abstracts]
TI: Convection of Very Short Lived Trace Gases into the TTL, UT and LS.
AU: * Moore, F L
EM: fred.moore@noaa.gov
AF: Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, United States
AU: * Moore, F L
EM: fred.moore@noaa.gov
AF: 2NOAA ESRL/GMD, 325 Broadway, Boulder, CO 80305, United States
AU: Dutton, G S
EM: geoff.dutton@noaa.gov
AF: Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, United States
AU: Dutton, G S
EM: geoff.dutton@noaa.gov
AF: 2NOAA ESRL/GMD, 325 Broadway, Boulder, CO 80305, United States
AU: Elkins, J W
EM: james.W.elkins@noaa.gov
AF: Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, United States
AU: Elkins, J W
EM: james.W.elkins@noaa.gov
AF: 2NOAA ESRL/GMD, 325 Broadway, Boulder, CO 80305, United States
AU: Hall, B D
EM: bradley.hall@noaa.gov
AF: 2NOAA ESRL/GMD, 325 Broadway, Boulder, CO 80305, United States
AU: Hurst, D F
EM: dale.hurst@noaa.gov
AF: Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, United States
AU: Hurst, D F
EM: dale.hurst@noaa.gov
AF: 2NOAA ESRL/GMD, 325 Broadway, Boulder, CO 80305, United States
AU: Nance, J D
EM: david.nance@noaa.gov
AF: Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, United States
AU: Nance, J D
EM: david.nance@noaa.gov
AF: 2NOAA ESRL/GMD, 325 Broadway, Boulder, CO 80305, United States
AB: The Tropical Tropopause Layer (TTL) can be isolated from the free troposphere for days to a month. Measurements of trace gases with similar local lifetimes of days to a month within the upper troposphere (UT), TTL, and lower stratosphere (LS) can identify convective events and reveal information about primary entry points, possible entrainment, and convective outflow. Episodic evidence of convective transport of Very Short Lived Species (VSLS) from the boundary layer to the UT and LS have been seen before. With CH3I for example, evidence for convection occurs primarily if the dominant convective inflow is from a source region within the boundary layer. This episodic data coupled with the host of measurements in missions like Tropical Composition, Cloud, and Climate Coupling experiment (TC4), will continue to improve our understanding of the convective process. At present, a gap exists between this episodic event driven data and an extrapolation to mean distributions and bulk transport. Trace gases like peroxylacytyl nitrate (PAN) have the potential to bridge this gap and may be more suited for integrated zonal comparisons. PAN is unique in two ways. First its lifetime in the TTL is on the order of the upper limit of the residence time of the TTL, and can survive a zonal trip around the globe. The value of PAN measured in the upper troposphere and lower stratosphere therefore contains a statistical distribution from zonal sources, sinks and convection, from within this month timescale. A second difference is that unlike most VSLS species, the source region for PAN extends above the trapped bounder layer. PAN measurements in the UT and TTL are therefore sensitive to convective inflow above the boundary layer in the lower troposphere, as is also the case for water isotope measurements. Most convective processes are highly turbulent with substantial entrainment expected. The dominant convective mass flux into the TTL may not come from the trapped boundary layer where most VSLS are prevalent.
DE: 0320 Cloud physics and chemistry
DE: 0322 Constituent sources and sinks
DE: 0340 Middle atmosphere: composition and chemistry
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting