Jovian Temperature and Cloud Variability during the 2009-2010 Fade of the South Equatorial Belt

Abstract

Mid-infrared 7-20 $\mu$m imaging of Jupiter demonstrates that the increased albedo of Jupiter's South Equatorial Belt (SEB) during the `fade' (whitening) event of 2009-2010 was correlated with changes to atmospheric temperature and aerosol opacity. The opacity of the tropospheric condensation cloud deck at pressures less than 800 mbar increased by 80% between May 2008 and July 2010, making the SEB ($7-17^{\circ }$ S) as opaque in the thermal infrared as the adjacent equatorial zone. After the cessation of discrete convective activity within the SEB in May 2009, a cool quiescent band of high aerosol opacity (the SEB zone at $11-15^{\circ }$ S) was observed separating the cloud-free northern and southern SEB components. The cooling of the SEBZ (with peak-to-peak contrasts of $1.0\pm 0.5$ K), as well as the increased aerosol opacity at 4.8 and 8.6 $\mu$m, preceded the visible whitening of the belt by several months. A chain of five warm, cloud-free `brown barges' (subsiding airmasses) were observed regularly in the SEB between June 2009 and June 2010, by which time they too had been obscured by the enhanced aerosol opacity of the SEB, although the underlying warm circulation was still present in July 2010. The cool temperatures and enhanced aerosol opacity of the SEBZ after July 2009 are consistent with an upward flux of volatiles from deeper levels (e.g., ammonia-laden air) and enhanced condensation, obscuring the blue-absorbing chromophore and whitening the SEB by April 2010. Revival of the dark SEB coloration in the coming months will ultimately require sublimation of these ices by subsidence and warming of volatile-depleted air. [Abridged]

arXiv comment22 pages, 11 figures, published in Icarus (2011)

Cited by in corpus (22)

• Mid-Infrared Mapping of Jupiter's Temperatures, Aerosol Opacity and Chemical Distributions with IRTF/TEXES
• Ideas for Citizen Science in Astronomy
• How well do we understand the belt/zone circulation of Giant Planet atmospheres?
• The Origin of Nitrogen on Jupiter and Saturn from the ${}^{15}$N/${}^{14}$N Ratio
• Instrumental Methods for Professional and Amateur Collaborations in Planetary Astronomy
• Moist Convection and the 2010-2011 Revival of Jupiter's South Equatorial Belt
• First ALMA Millimeter Wavelength Maps of Jupiter, with a Multi-Wavelength Study of Convection
• Jupiter's Deep Cloud Structure Revealed Using Keck Observations of Spectrally Resolved Line Shapes
• Jupiter's North Equatorial Belt expansion and thermal wave activity ahead of Juno's arrival
• Cycles of Activity in the Jovian Atmosphere
• Jupiter's Atmospheric Variability from Long-Term Ground-based Observations at 5 microns
• Observations and numerical modelling of a convective disturbance in a large-scale cyclone in Jupiter's South Temperate Belt
• Unexpected Long-Term Variability in Jupiter's Tropospheric Temperatures
• Dynamics and Clouds in Planetary Atmospheres from Telescopic Observations
• Jupiter's Mesoscale Waves Observed at 5 $\mu$m by Ground-Based Observations and Juno JIRAM
• Jupiter's Para-H${}_2$ Distribution from SOFIA/FORCAST and Voyager/IRIS 17-37 $\mu$m Spectroscopy
• Spatial distribution of Jovian clouds, hazes and colors from Cassini ISS multi-spectral images
• A dispersive wave pattern on Jupiter's fastest retrograde jet at $20^{\circ }$S
• The Thermal Structure and Composition of Jupiter's Great Red Spot From JWST/MIRI
• Long-term K${}_S$-band photometric monitoring of L dwarfs
• The need for Professional-Amateur collaborations in studies of Jupiter and Saturn
• Jupiter's South Equatorial Belt cycle in 2009-2011: II, The SEB Revival