### Abstract

It is assumed that observed zonal currents in the atmospheres of Jupiter and Saturn correspond to a state of permanent rotation, and that the angular velocity is constant on cylindrical surfaces parallel to the rotation axis. The equation of hydrostatic equilibrium for a rotating planet is solved under these restrictive assumptions, and the effect of the hypothesized rotation state on the planet's gravity harmonics and external shape is investigated. Spacecraft data on zonal currents are used to derive nearly model-independent corrections to the first four zonal gravity harmonic coefficients, which can be used to correct observed gravity harmonics to values appropriate for solid-body rotation. If the assumed rotation state is applicable, then zonal currents lead to measurable topography of isopycnic surfaces with respect to the reference fihure defined by the magnetospheric rotation period and the gravity harmonics. The amplitude of the topography is on the order of 5 km for Jupiter and 60 km for Saturn.

Original language | English (US) |
---|---|

Pages (from-to) | 509-515 |

Number of pages | 7 |

Journal | Icarus |

Volume | 52 |

Issue number | 3 |

DOIs | |

State | Published - 1982 |

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### ASJC Scopus subject areas

- Space and Planetary Science
- Astronomy and Astrophysics

### Cite this

**Effects of differential rotation on the gravitational figures of Jupiter and Saturn.** / Hubbard, William B.

Research output: Contribution to journal › Article

*Icarus*, vol. 52, no. 3, pp. 509-515. https://doi.org/10.1016/0019-1035(82)90011-2

}

TY - JOUR

T1 - Effects of differential rotation on the gravitational figures of Jupiter and Saturn

AU - Hubbard, William B.

PY - 1982

Y1 - 1982

N2 - It is assumed that observed zonal currents in the atmospheres of Jupiter and Saturn correspond to a state of permanent rotation, and that the angular velocity is constant on cylindrical surfaces parallel to the rotation axis. The equation of hydrostatic equilibrium for a rotating planet is solved under these restrictive assumptions, and the effect of the hypothesized rotation state on the planet's gravity harmonics and external shape is investigated. Spacecraft data on zonal currents are used to derive nearly model-independent corrections to the first four zonal gravity harmonic coefficients, which can be used to correct observed gravity harmonics to values appropriate for solid-body rotation. If the assumed rotation state is applicable, then zonal currents lead to measurable topography of isopycnic surfaces with respect to the reference fihure defined by the magnetospheric rotation period and the gravity harmonics. The amplitude of the topography is on the order of 5 km for Jupiter and 60 km for Saturn.

AB - It is assumed that observed zonal currents in the atmospheres of Jupiter and Saturn correspond to a state of permanent rotation, and that the angular velocity is constant on cylindrical surfaces parallel to the rotation axis. The equation of hydrostatic equilibrium for a rotating planet is solved under these restrictive assumptions, and the effect of the hypothesized rotation state on the planet's gravity harmonics and external shape is investigated. Spacecraft data on zonal currents are used to derive nearly model-independent corrections to the first four zonal gravity harmonic coefficients, which can be used to correct observed gravity harmonics to values appropriate for solid-body rotation. If the assumed rotation state is applicable, then zonal currents lead to measurable topography of isopycnic surfaces with respect to the reference fihure defined by the magnetospheric rotation period and the gravity harmonics. The amplitude of the topography is on the order of 5 km for Jupiter and 60 km for Saturn.

UR - http://www.scopus.com/inward/record.url?scp=0010998162&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0010998162&partnerID=8YFLogxK

U2 - 10.1016/0019-1035(82)90011-2

DO - 10.1016/0019-1035(82)90011-2

M3 - Article

AN - SCOPUS:0010998162

VL - 52

SP - 509

EP - 515

JO - Icarus

JF - Icarus

SN - 0019-1035

IS - 3

ER -