1

Jovian Stratospheric Circulation: Insights from Cassini

Observations

X. Zhang (1), R. Cosentino (2), R. Morales-Juberias (2), R. A. West (3), S. Coffing (2), T. E. Dowling (4), M. Allen (3) and Y. L. Yung (1)

(1 )Caltech, USA(2) New Mexico Institute of Mining and Technology, USA(3) JPL, USA(4) University of Louisville, Kentucky, USA

2

Model Atmosphere

CH4 T

Nixon et al. (2007) Yelle (2001)

3

C2H2C2H6

CIRS data (Nixon et al., 2007)

Model Atmosphere

4

ISS Image (phase angle: 17.5 degree)

UV1 (258 nm) MT3 (889 nm) CB3 (938 nm)

5

Solar Heating Rate (erg/g/s)

6

Thermal Cooling Rate (erg/g/s)

Net Heating Rate(erg/g/s)

7

Zonal wind from EPIC-2D

8

Residual Circulation

Streamfunction (g/cm/s)

9

Conclusion• Jet structures seen in the stratosphere of Jupiter

• Residual mean circulation implies the meridional mass transport timescale at 1 mbar ~109 s, compared with C2H2 lifetime ~ 107 s and C2H6 lifetime ~ 1010 s

10

Backup Slides

11

12

Residual Circulation (gas only)

13

Temperature from EPIC-2D

14

D_theta/Dt from EPIC-3D

15

Model

Haze layer:

Aggregated particles (high latitude) Or Mie particles (low latitude)

Refractive index from Ramirez et al. (2002)

Methane, Rayleigh Scattering

Methane, Rayleigh ScatteringP~500 mbar

P~0.3 mbar

P~100 mbar

Profile based on that from Banfield et al. (1998)

Cloud layer:Mie particles: 0.7 micron, 1.535+0i