| Autor: |
Bardet, Deborah1 (AUTHOR) db528@leicester.ac.uk, Donnelly, Padraig T.2 (AUTHOR), Fletcher, Leigh N.1 (AUTHOR), Antuñano, Arrate3 (AUTHOR), Roman, Michael T.1 (AUTHOR), Sinclair, James A.4 (AUTHOR), Orton, Glenn S.4 (AUTHOR), Tao, Chihiro5 (AUTHOR), Rogers, John H.6 (AUTHOR), Melin, Henrik1 (AUTHOR), Harkett, Jake1 (AUTHOR) |
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| Zdroj: |
Journal of Geophysical Research. Planets. Feb2024, Vol. 129 Issue 2, p1-33. 33p. |
| Abstrakt: |
Using images at multiple mid‐infrared wavelengths, acquired in 2018 May using the Very Large Telescope Imager and Spectrometer (VISIR) instrument on ESO's Very Large Telescope (VLT), we study Jupiter's pole‐to‐pole thermal, chemical and aerosol structure in the troposphere and stratosphere. We confirm that the pattern of cool and cloudy anticyclonic zones and warm cloud‐free cyclonic belts persists throughout the mid‐latitudes, up to the polar boundaries, and evidence a strong correlation with the vertical maximum windshear and the locations of Jupiter's zonal jets. At high latitudes, VISIR images reveal a large region of mid‐infrared cooling poleward ∼64°N and ∼67°S extending from the upper troposphere to the stratosphere, co‐located with the reflective aerosols observed by JunoCam, and suggesting that aerosols play a key role in the radiative cooling at the poles. Comparison of zonal‐mean thermal properties and high‐resolution visible imaging from Juno allows us to study the variability of atmospheric properties as a function of altitude and jet boundaries, particularly in the cold southern polar vortex. However, the southern stratospheric polar vortex is partly masked by a warm mid‐infrared signature of the aurora. Co‐located with the southern main auroral oval, this warming results from the auroral precipitation and/or joule heating which heat the atmosphere and thus cause a significant stratospheric emission. This high emission results from a large enhancement of both ethane and acetylene in the polar region, reinforcing the evidence of enhanced ion‐related chemistry in Jupiter's auroral regions. Plain Language Summary: A fundamental inquiry driving NASA's Juno mission was the investigation of the potential changes of Jupiter's famous banded structure below the top most clouds. As NASA's Juno spacecraft lacks instrumentation sensitive to the mid‐infrared, we have used the ground‐based Very Large Telescope Imager and Spectrometer (VISIR) on ESO's Very Large Telescope (VLT) to support the mission since 2016. The 2018 May data set provides a comprehensive view of Jupiter's pole‐to‐pole thermal, chemical, and aerosol structure; including the Great Red Spot; and the auroral‐related heating in the southern polar stratosphere. We show that the alternating pattern of cool cloudy zones and warm cloud‐free belts correlate to the zonal winds locations, extends from the equator to the boundary of the polar vortices (∼64°N and ∼67°S). Comparing this ground‐based data set with Juno observations, we show that the polar regions experience radiative cooling from the upper troposphere to the stratosphere, probably induced by the reflective polar aerosols, and confined at the poles by the polar vortices. However, the southern stratospheric polar vortex is partly masked by a large auroral emission, a signature of an interaction between the magnetosphere and stratosphere of Jupiter, which causes a ∼20 K warming as deep as the middle stratosphere. Excess hydrocarbons within the polar domain reinforces the evidence of enhanced ion‐related chemistry in Jupiter's auroral regions, resulting from charged particles precipitating from the top of the atmosphere to lower altitudes. Key Points: Jupiter's belt/zone thermal structure extends from the equator to the edge of the polar vortices and correlates with the zonal jetsThe cold polar vortices coincides with reflective aerosols, suggesting dynamical entrainment by the northernmost and southernmost jetsTemporal evolution of the southern auroral hotspot shows a stratospheric cooling after a solar wind compression event [ABSTRACT FROM AUTHOR] |
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GreenFILE |
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