HR: 1330h
AN: A32B-0151    [PDF]
TI: Summertime Dynamics of the Middleworld Revealed by Aircraft Missions During the Last Decade
AU: * Pittman, J V
EM: vellovic@huarp.harvard.edu
AF: Harvard University, Department of Chemistry and Chemical Biology, Cambridge, MA 02138 United States
AU: Sayres, D S
EM: sayres@huarp.harvard.edu
AF: Harvard University, Department of Chemistry and Chemical Biology, Cambridge, MA 02138 United States
AU: Smith, J B
EM: jxsmith@huarp.harvard.edu
AF: Harvard University, Department of Chemistry and Chemical Biology, Cambridge, MA 02138 United States
AU: Weinstock, E M
EM: weinstock@huarp.harvard.edu
AF: Harvard University, Department of Chemistry and Chemical Biology, Cambridge, MA 02138 United States
AU: Anderson, J G
EM: anderson@huarp.harvard.edu
AF: Harvard University, Department of Chemistry and Chemical Biology, Cambridge, MA 02138 United States
AU: Wofsy, S C
EM: scw@io.harvard.edu
AF: Harvard University, Department of Earth and Planetary Sciences, Cambridge, MA 02138 United States
AU: Richard, E C
EM: richard@al.noaa.gov
AF: NOAA, Aeronomy Laboratory, Boulder, CO 80305 United States
AU: Weinheimer, A J
EM: wein@ucar.edu
AF: NCAR, Atmospheric Chemistry Division, Boulder, CO 80303 United States
AU: Ridley, B A
EM: ridley@ucar.edu
AF: NCAR, Atmospheric Chemistry Division, Boulder, CO 80303 United States
AU: Loewenstein, M
EM: mloewenstein@mail.arc.nasa.gov
AF: NASA Ames, Ames Research Center, Moffett Field, CA 94035 United States
AB: In situ measurements provide high resolution, high accuracy data that can be used to study the effects of both local and global scale transport. In this study, we focus on the middleworld, a region of the atmosphere where negative trends in midlatitude ozone and positive trends in water vapor have been reported during the last decade. Changes in these trace gases affect the radiative properties of this region, and can lead to negative impacts on human health. This region of the atmosphere is dynamically coupled to both the troposphere, via stratosphere-troposphere exchange driven by wave-breaking events, isentropic transport, and/or convective penetration, and to the overworld, via diabatic descent from the tropical stratosphere. The interaction between these regions results in air masses with distinct signatures. During the CRYSTAL FACE mission in July of 2002, tracer measurements in the middleworld indicated significant transport of high latitude air into the subtropics. We compare back trajectories of air parcels sampled over Florida to the location and dates of sondes launched in North America to search for acceptable matches in space and time. We then compare the selected sonde values to in situ aircraft data in order to investigate the strength of mixing processes responsible for the make-up of the air parcel sampled by the aircraft. Additionally, in order to understand the geographic dependence and the importance of this transport process, we compare and contrast in situ tracer-tracer correlations from various aircraft missions during the summer, namely ASHOE, STRAT, POLARIS, CWVCS, and CRYSTAL FACE. This combined dataset is used to identify the variability of the transport mechanisms present in the northern latitude middleworld, between 75 and 155 degrees West, and their longitudinal dependence.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0325 Evolution of the atmosphere
DE: 0341 Middle atmosphere--constituent transport and chemistry (3334)
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting