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

Abstract

AbstractWe 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.