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Keck adaptive optics images of Jupiter’s north polar cap and Northern Red Oval |
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| Authors: | Imke de Pater Michael H Wong Heidi B Hammel Máté Ádámkovics |
| Institution: | a Astronomy Department, 601 Campbell Hall, University of California, Berkeley, CA 94720, USA b Delft Institute of Earth Observation and Space Systems, Delft University of Technology, NL-2629 HS Delft, The Netherlands c SRON Netherlands Institute for Space Research, 3584 CA Utrecht, The Netherlands d Association of Universities for Research in Astronomy, 1212 New York Avenue NW, Suite 450, Washington, DC 20005, USA e Space Science Institute, 4750 Walnut Avenue, Suite 205, Boulder, CO 80301, USA f W.M. Keck Observatory, Waimea, HI 96743, USA g Max-Planck-Institut fuer Astronomie Koenigstuhl 17, D-69117 Heidelberg, Germany |
| Abstract: | We present observations at near-infrared wavelengths (1-5 μm) of Jupiter’s north polar region and Northern Red Oval (NN-LRS-1). The observations were taken with the near-infrared camera NIRC2 coupled to the adaptive optics system on the 10-m W.M. Keck Telescope on UT 21 August 2010. At 5-μm Jupiter’s disk reveals considerable structure, including small bright rings which appear to surround all small vortices. It is striking, though, that no such ring is seen around the Northern Red Oval. In de Pater et al. 2010a. Icarus 210, 742-762], we showed that such rings also exist around all small vortices in Jupiter’s southern hemisphere, and are absent around the Great Red Spot and Red Oval BA. We show here that the vertical structure and extent of the Northern Red Oval is very similar to that of Jupiter’s Red Oval BA. These new observations of the Northern Red Oval, therefore, support the idea of a dichotomy between small and large anticyclones, in which ovals larger than about two Rossby deformation radii do not have 5-μm bright rings. In de Pater et al. 2010a. Icarus 210, 742-762], we explained this difference in terms of the secondary circulations within the vortices. We further compare the brightness distribution of our new 5-μm images with previously published radio observations of Jupiter, highlighting the depletion of NH3 gas over areas that are bright at 5 μm. |
| Keywords: | Jupiter Atmosphere Infrared observations Adaptive optics |
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