1. A Preliminary Meteorological Interpretation of Correlated Huygens DWE and HASI Data M. Allison, F. Ferri, M.K. Bird, M. Fulchignoni, S.W. Asmar, D.H. Atkinson, G. Colombatti, G.L. Tyler and the DWE and HASI Experiment Teams DPS Cambridge - Poster 45.03 Wednesday, 7 September 2005

2. DWE Wind / HASI Temperature

3. Wind Shear & Buoyant Stability

4. Richardson Number

5. Zonal Wind Section

6. Planetary Boundary Layer?

7. Preliminary Conclusions 1.An initial correlated analysis of Huygens DWE and HASI data reveals a significant correspondence of wind-shear and buoyant stability structures, both in Titan’s stratosphere and the apparent planetary boundary layer of its lower troposphere. 2.Lower stratosphere: The unanticipated strong vertical wind shear region between 60 and 90 km altitude is correlated with Titan’s most buoyantly stratified region – a layer of roughly one-scale-height where the smoothed Richardson number is small (Ri ~2–5). The “potential vorticity mixing” theory for planetary circulation implies that this region (15–30 hPa) may be characterized by relatively flat isotachs, as may be further illuminated by thermal wind studies of the Cassini CIRS data. 3.Near-surface atmosphere: A correlation of HASI and DWE data for suggests a boundary layer characterized by well-mixed potential temperature, strong vertical shears, and a thin region of Richardson number Ri~1 over the lowest 3 km.