First measurements of the Jovian zonal winds profile through visible Doppler spectroscopy

Description

We present the first measurements of Jupiter's wind profile obtained from radial-velocity measurements. Radial velocity measurements of wind are rather difficult, but can be very interesting as they measure the actual speed of cloud particles instead of the motion of large cloud structures. Here we present the first scientific results of the Doppler spectro-imager JOVIAL-JIVE, dedicated to giant planets' seismology and atmospheric dynamics. The instrument provides instantaneous velocity maps in the mid-visible domain by monitoring the Doppler shift of solar Fraunhofer lines reflected in the planets' upper atmosphere thanks to an imaging Fourier transform spectrometer. We present profiles of the zonal wind speed of Jupiter as function of latitude from observations obtained between 2015 and 2017. Our results are compared with wind profiles obtained by cloud tracking from HST images at the same epoch. We point out comparable results from both techniques except at the latitude of the hot spots in the northern equatorial band (≈ 5 • N) where we find a much lower wind speed.

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