1. Stratosphere-Troposphere Analyses of Regional Transport (START) Experiment Investigators: Laura Pan (PI) Andy Weinheimer (Integration and Payload) Rushan Gao (NOAA, O 3 ) Teresa Campos (H 2 O, CO) Chris Davis (Forecast, flight planning) Mel Shapiro (flight planning) Don Lenschow (mesoscale dynamics) Ken Bowman (Texas A&M, large scale dynamics, trajectory analyses)

2. Science Objectives 1.Characterize the dynamical structure of the extratropical tropopause region in and around the subtropical jet (STJ) using measurements of dynamical and chemical tracers. 2.Characterize the structure of the chemical transition layer from the troposphere to stratosphere across the extratropical tropopause. 3.Characterize irreversible STE & mixing 4.Investigate the role of large vs small scale dynamical processes in controlling STE

3. Mixing on top of the STJ Convective transport Long range transport Transport processes that impact the chemical distribution of the Ex-UTLS

4. DU/km Ozone climatology, June Poleward transport above jet weak transport near jet core Signature of frequent intrusions? Slide Courtesy Bill Randel Data from Fortuin and Kelder, 1998 DU/km

5. CO profiles as a function of altitude relative to the tropopause DH (Alt - TPH) (km) [Pan et al., JGR 2004]

6. What about the horizontal transport boundary?

7. Altitude (km) POLARIS 970710 [Pan et al., 2004 JGR]

8. ER-2 data O 3 -H 2 O (POLARIS) Use of the tracer correlation to identify stratosphere, troposphere and transition layer

9. Trop. E. P. Strat. E. P. Tropopause DC-8 alt Pan et al., 2005

11. u Mixing locations are identified using O3-H2O relationship. The locations coincide with the regions of large gradients of zonal wind field. Is the deformation in the large scale winds the dominant factor in producing mixing in the global scale? O3O3 What controls mixing?

12. Strong gradient caseWeak gradient case Where does mixing occur? (simulated mixing from CLaMS model) u u

13. Synoptic scale - Stratospheric intrusion

14. ± 2 day trajectory analyses Red: Boundaries of rapidly approaching air parcels (back) Green: Boundaries of rapidly departing of air parcels (forward) From Ken Bowman

15. from Todd Lane GW and mesoscale model

16. Gravity Wave Synoptic Environment (Uccelini and Koch 1987) V g Observations: 13 documented cases of mesoscale gravity waves; L~100-200km Preferred region: exit region of upper jet streak; cold side of surface frontal boundary Leading hypothesis of wave generation: geostrophic adjustment

17. xx Flight profile 1: survey of STJ

19. Flight profile 2: survey of chemical transition

20. Flight profile 3: Sampling of stratospheric intrusion - The next 3 pages are examples from AVE Houston Oct-Nov 2004

24. Thank you!