TY - JOUR

T1 - Baroclinic instabilities in Jupiter's zonal flow

AU - Gierasch, Peter J.

AU - Ingersoll, Andrew P.

AU - Pollard, David

N1 - Funding Information:
atmospherIeca. rus 33, 388-409. MCINTYRE, M. E. (1972)B. aroclinicin stabilityo f an BARCILON, A., AND GIERASCH,P . J. (1970).A moist Hadley cell model for Jupiter's cloud bands.J . Atmos. Sci. 27, 550-560. CHARNEY, J. G., AND STERN, M. E. (1962).O n the stabilityo f internabl aroclinijce tsi n a rotatinga tmo-sphereJ.. Atmos. Sci. 19, 159-172. EADY, E. T. (1949)L. ong wavesa ndc yclinew aves. Tellus l, 33-52. GIERASCH, P. J. (1976)J.o vian meteorologyla: rge-scalem oistc onvectionIc.a rus 29, 445-454. GIERASCH,P . J., AND GOODY,R . M. (1969).R adiative time constantsin the atmospheroef Jupiter. J. Atmos. Sci. 26, 979-980. GIERASCH, P. J., INGERSOLL,A . P., AND WILLIAMS, R. T. (1973)R. adiativein stabilitoy f a cloudyp lanet-ary atmospherIec.a rus 19, 473-481. GILL, A. E., GREEN, J. S. A., AND SIMMONS,A . J. (1974).E nergyp artitionin the large-scaloec eanc ir-culationa nd the productiono f mid-oceane ddies. Deep-Sea Res. 21, 499-528. HESS, S. L., AND PANOFSKY, H. A. (1951)T. he atmo-sphereso f the other planets.In Compendium of Meteorology (T. F. Malone, Ed.), pp. 391-398. Amer. MeteorolS. oc.,Boston. HOLTON, J. R. (1972).A n Introduction to Dynamic This work was supporteidn part by NASA Grant idealizedm odeol f the polarn ightje t.Q uart. J. Roy. NGL 05-002-00t3o the CaliforniaIn stituteo f Technol-Meteorol. Soc. 98, 165-174. ogy and by Grant NGL 33-010-18f6r om the NASA PEEK, B. M. (1958).T he Planet PlanetaryA tmospherePsr ogramt o Cornell Univer-Faber,L ondon. sity. EJ.G. acknowledgethse s upporot f an Alfred P. SMITH, B. A., SODERBLOM,L . A., JOHNSON,T . V., Sloan researcfhe llowshipT. his paperis Contribution INGERSOLL, m. P., COLLINS, S. A., SHOEMAKER, Number3 112o f the Divisiono f Geologicaal ndPlanet-E. M., HUNT, G. E. MASURSKY, H., CARR, M. H., ary Sciences,C alifornia Institute of Technology, DAVIES, M. E., COOKI I, A. F., BOYCE, J., DANIEL-PasadenaC,a lifornia9, 1125. SON, G. E., OWEN, T., SAGAN, C., BEEBE, R. F., VEVERKA, J., STROM, R. G., McCAULEY, J. F., MORRISON,D ., BRIGGS,G . A., SUOMI, V. E. (1979). The Jupiter systemth roughth ee yeso f VoyagerI. Science 204,9 51-972. STEVENSON,D . J., AND SALPETER,E . E. (1976)I.n ter-ior modelso f Jupiter. In Jupiter (T. Gehrels,E d.), pp. 85-112.U niv. of ArizonaP ress,T ucson. STEVENSON,D . J., AND SALPETER,E . E. (1977).T he phase diagram and transport properties for hydrogen-heliuflmui d planetsA.s tron. J. Suppl. 35, 221-237. STONE, P. H. (1967).A n applicatioonf baroclinics ta-bility theoryt o the dynamicso f the Jovian atmo-sphereJ.. Atmos. Sci. 24, 642-652. STONE, P. H. (1972).A simplifiedra diative-dynamical model for the static stability of rotatinga tmo-spheresJ.. Atmos. Sci. 29, 405-418. STONE, E H. (1976)T. he meteorologoyf the Jovian atmospherIen. Jupiter (T. Gehrels,E d.), pp. 586-620. Univ. of ArizonaP ress,T ucson. WEIDENSCHILLING, S. J., AND LEWIS, J. S. (1973). Atmospherica nd cloud structureso f the Jovian planetsI.c arus 20, 465-476. WILLIAMS, G. P. (1978). Planetaryc irculations1: . Barotropicr epresentatioonf Jovian and terrestrial turbulenceJ.. Atmos. Sci. 35, 1399-1426. WILLIAMS, G. P. (1979)P. lanetarcyi rculations2:. The Jovian quasi-geostrophreicg imeJ.. Atmos. Sci. 36, 932-968.

PY - 1979/11

Y1 - 1979/11

N2 - The baroclinic stability of Jupiter's zonal flow is investigated using a model consisting of two continuously stratified fluid layers. The upper layer, containing a zonal shear flow and representing the Jovian cloudy regions above p ∼ 5 bars, is the same as Eady's (1949) model for the Earth. The lower layer has a relatively large but finite depth with a quiescent basic state, representing the deep Jovian fluid bulk below p ∼ 5 bars. Due to the presence of the lower layer, the linearized non-dimensional growth rates are drastically reduced from the O(1) growth rates of the original Early model. Only very long wavelengths relative to the upper fluid's radius of deformation L1 are unstable. Eddy transports of heat are also reduced relative to estimates based on scaling arguments alone. Since the hydrostatic approximation for the lower-layer perturbation breaks down at great depths, a second model is presented in which energy propagates downward in an infinitely deep lower fluid obeying the full linearized fluid equations. In this model, the growth rates are again very small, but now all wavelengths are unstable with maximum growth rates occurring for wavelengths O(1) relative to L1. These results illustrate the importance for the upper-layer meteorology of the interface boundary condition with the lower fluid, which is radically different from the rigid lower boundary of the Earth's troposphere.

AB - The baroclinic stability of Jupiter's zonal flow is investigated using a model consisting of two continuously stratified fluid layers. The upper layer, containing a zonal shear flow and representing the Jovian cloudy regions above p ∼ 5 bars, is the same as Eady's (1949) model for the Earth. The lower layer has a relatively large but finite depth with a quiescent basic state, representing the deep Jovian fluid bulk below p ∼ 5 bars. Due to the presence of the lower layer, the linearized non-dimensional growth rates are drastically reduced from the O(1) growth rates of the original Early model. Only very long wavelengths relative to the upper fluid's radius of deformation L1 are unstable. Eddy transports of heat are also reduced relative to estimates based on scaling arguments alone. Since the hydrostatic approximation for the lower-layer perturbation breaks down at great depths, a second model is presented in which energy propagates downward in an infinitely deep lower fluid obeying the full linearized fluid equations. In this model, the growth rates are again very small, but now all wavelengths are unstable with maximum growth rates occurring for wavelengths O(1) relative to L1. These results illustrate the importance for the upper-layer meteorology of the interface boundary condition with the lower fluid, which is radically different from the rigid lower boundary of the Earth's troposphere.

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U2 - 10.1016/0019-1035(79)90067-8

DO - 10.1016/0019-1035(79)90067-8

M3 - Article

AN - SCOPUS:0011515606

VL - 40

SP - 205

EP - 212

JO - Icarus

JF - Icarus

SN - 0019-1035

IS - 2

ER -