HR: 1330h
AN: A32B-0150    [PDF]
TI: Mixing Near the Subtropical Jet - a Case Study
AU: * Pan, L L
EM: liwen@ucar.edu
AF: National Center for Atmospheric Research, 1850 Table Mesa Drive, Boulder, CO 80305 United States
AU: Randel, W J
EM: randel@ucar.edu
AF: National Center for Atmospheric Research, 1850 Table Mesa Drive, Boulder, CO 80305 United States
AU: Browell, E
EM: e.v.browell@larc.nasa.gov
AF: NASA Langley Research Center, 100 NASA Road, Hampton, VA 23681 United States
AU: Mahoney, M J
EM: Michael.J.Mahoney@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109
AB: Mixing is an important part of irreversible stratosphere troposphere exchange. Yet the mixing process is poorly understood. We present a case study of mixing in the vicinity of the subtropical jet, using airborne in situ and remote sensing data during SONEX mission. The case of intrusion of stratospheric air is identified using ozone profile curtains from DIAL LIDAR onboard DC-8. The thermal structure across the tropopause is mapped using temperature profiles from Microwave Temperature Profiler (MTP), together with the potential vorticity field based on the ECMWF data. Spatial extent of mixing between stratospheric and tropospheric air is examined using tracer relationships from in situ measurement onboard DC-8. Results show that mixing between stratospheric and tropospheric air involved air mass with ozone value up to ~400 ppbv. The case study also show that based on the tracer relationship alone, without the background information provided by the LIDAR data and MTP data, it is often difficult to conclude whether the observed mixing represent stratosphere to troposphere transport or troposphere to stratosphere transport. Results also show that using 2 PVU or 3.5 PVU contour as the tropopause in this case will likely underestimate the stratosphere to troposphere transport.
DE: 3300 METEOROLOGY AND ATMOSPHERIC DYNAMICS
DE: 3362 Stratosphere/troposphere interactions
DE: 3364 Synoptic-scale meteorology
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting