Jupiter cloud morphology and zonal winds from ground‐based observations before and during Juno's first perijove

Abstract

We analyze Jupiter observations between December 2015 and August 2016 in the 0.38–1.7 μm wavelength range from the PlanetCam instrument at the 2.2 m telescope at Calar Alto Observatory and in the optical range by amateur observers contributing to the Planetary Virtual Observatory Laboratory. Over this time Jupiter was in a quiescent state without notable disturbances. Analysis of ground‐based images and Hubble Space Telescope observations in February 2016 allowed the retrieval of mean zonal winds from −74.5° to +73.2°. These winds did not change over 2016 or when compared with winds from previous years with the sole exception of intense zonal winds at the North Temperate Belt. We also present results concerning the major wave systems in the North Equatorial Belt and in the upper polar hazes visible in methane absorption bands, a description of the planet's overall cloud morphology and observations of Jupiter hours before Juno's orbit insertion.

Cycles of activity in the Jovian atmosphere

“…No comparable cyclonic circulations were noted in the NTB jet prior to the eruption. However, it has been noted that the zonal jet at 23.9°N gradually accelerates prior to these disturbances [ Sánchez‐Lavega et al , ; Rogers et al , ], and the same was true in 2016 [ Hueso et al ., ].…”

A planetary‐scale disturbance in the most intense Jovian atmospheric jet from JunoCam and ground‐based observations

“…Jupiter's wind profile at the upper cloud level was measured in 2016 before the outbreak, using cloud automatic tracking on a large set of images and HST image pairs from February 2016 and also using ground‐based observations with small telescopes up to May 2016 [ Hueso et al ., ]. We use the NTBs HST jet profile as a reference for the motions and dynamics of the NTBD.…”

“…observations with small telescopes up to May 2016 [Hueso et al, 2017b]. We use the NTBs HST jet profile as a reference for the motions and dynamics of the NTBD.…”

“…We have employed two dynamical models to simulate the observed cloud field and motions of the NTBD: a shallow water (SW) model [Legarreta et al, 2016; García-Melendo and Sánchez-Lavega, 2017] and the Explicit Figure 4. Meridional profile of the NTBs jet stream as measured using HST images on 9-10 February 2016 about 7-8 months before the outbreak (black curve with wind error measurement indicated [Hueso et al, 2017b]). The velocity and location of the NTBD disturbance features are shown as dots: green for the plumes (A, C, and D), blue dots for long-term tracked features (dark and white spots, tracking for 5-10 days), and circles for all kind of features (tracking on Pic-du-Midi images for about 50 h using two methods).…”

First Estimate of Wind Fields in the Jupiter Polar Regions From JIRAM‐Juno Images

“…The case of Jupiter is, by no means, an exception. Global‐scale zonal wind profiles have been derived from a variety of data sets: Voyager Imaging Science System (Ingersoll et al, ; Limaye, ), Hubble Space Telescope (Garcìa‐Melendo & Sánchez‐Lavega, ), Cassini Imaging Science Subsystem, during the Jupiter flyby of December 2000 (Porco et al, ), and ground‐based telescopic observations (Hueso et al, ). These studies suggest a long‐term stability of the inferred latitudinal profiles of mean zonal winds.…”