jovian stratospheric circulation: insights from cassini observations

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

Radiative Model

Circulation

Chemical tracers

Net Heating

Rate

Chemical Model

3

Model Atmosphere

CH4 T

Nixon et al. (2007) Yelle (2001)

4

C2H2C2H6

CIRS data (Nixon et al., 2007)

Model Atmosphere

5

ISS Image (phase angle: 17.5 degree)

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

6

Solar Heating Rate (erg/g/s)

For haze information, see P119: Zhang, et al., Aerosol and Cloud in the Atmosphere of Jupiter, EPSC-DPS2011-311

7

Thermal Cooling Rate (erg/g/s)

Net Heating Rate(erg/g/s)

8

Zonal Wind from EPIC-2D

9

Residual Mean Circulation

Mass Streamfunction (g/cm/s)

With haze w/o haze

10

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

11

Seasonal Change?

Nixon et al. (2010)

12

Backup Slides

13

14

Temperature used in EPIC-2D

15

D_theta/Dt from EPIC-3D

16

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)