When
3:30 p.m., Oct. 19, 2010
Where
Kuiper Space Sciences 308
Yohai Kaspi, NOAA Climate and Global Change Postdoctoral Fellow at the California Institute of Technology, is the scheduled speaker. Host: Adam Showman.
Deep winds on giant planets and the Juno mission to Jupiter
Abstract: A key question regarding the atmospheric dynamics on giant planets is how deep are the zonal winds which are observed at the cloud-level. A common assumption is that the observed cloud-level winds extend along cylinders parallel to the axis of rotation into the interior. In this talk we discuss briefly the theory leading to this assumption, but show that entropy gradients caused by the internal
convection can lead to zonal wind shear along the direction of the axis of rotation, and therefore the interior winds will be weaker than the winds at cloud level. We demonstrate this using a new 3D compressible
general circulation model. The upcoming Juno mission to Jupiter, which will perform high resolution observations of Jupiter's gravity field, is likely to give us information about the depth of the winds. We discuss how the deep winds affect the gravity harmonics, and present a new thermal-wind method from which we can infer the expected gravity harmonics as a function of the wind depth. We find that if the winds are even a few hundred km deep they should be detectable by Juno.
Deep winds on giant planets and the Juno mission to Jupiter
Abstract: A key question regarding the atmospheric dynamics on giant planets is how deep are the zonal winds which are observed at the cloud-level. A common assumption is that the observed cloud-level winds extend along cylinders parallel to the axis of rotation into the interior. In this talk we discuss briefly the theory leading to this assumption, but show that entropy gradients caused by the internal
convection can lead to zonal wind shear along the direction of the axis of rotation, and therefore the interior winds will be weaker than the winds at cloud level. We demonstrate this using a new 3D compressible
general circulation model. The upcoming Juno mission to Jupiter, which will perform high resolution observations of Jupiter's gravity field, is likely to give us information about the depth of the winds. We discuss how the deep winds affect the gravity harmonics, and present a new thermal-wind method from which we can infer the expected gravity harmonics as a function of the wind depth. We find that if the winds are even a few hundred km deep they should be detectable by Juno.