Microphysical Model of Jupiter's Great Red Spot Upper Chromophore Haze

Abstract

The origin of the red colouration in Jupiter's Great Red Spot (GRS) is a long-standing question in planetary science. While several candidate chromophores have been proposed, no clear conclusions have been reached regarding its nature, evolution, or relationship to atmospheric dynamics. In this work, we perform microphysical simulations of the reddish haze over the GRS and quantify the production rates and timescales required to sustain it. Matching the previously reported chromophore column mass and effective radius in the GRS requires column-integrated injection fluxes in the range $1\times 10^{-12}$-$7\times 10^{-12}$ kg m${}^{-2}$ s${}^{-1}$, under low upwelling velocities in the upper troposphere ($v_{\mathrm{trop}}\lesssim 1.5\times 10^{-4}$ m s${}^{-1}$) and particle charges of at least 20 electrons per $\mu$m. Such rates exceed the mass flux that standard photochemical models of Jupiter currently supply via NH${}_3$-C${}_2$H${}_2$ photochemistry at 0.1-0.2 bar, the most popular chromophore pathway in recent literature. We find a lower limit of 7 years on the haze formation time. We also assess commonly used size and vertical distribution parameterisations for the chromophore haze, finding that eddy diffusion prevents the long-term confinement of a thin layer and that the extinction is dominated by particles that can be represented by a single log-normal size distribution.

47 pages, 16 figures. Accepted for publication in Icarus

References in corpus (11)

• Sulfur Hazes in Giant Exoplanet Atmospheres: Impacts on Reflected Light Spectra
• Colour and Tropospheric Cloud Structure of Jupiter from MUSE/VLT: Retrieving a Universal Chromophore
• Jupiter's Equatorial Plumes and Hot Spots: Spectral Mapping from Gemini/TEXES and Juno/MWR
• Assessing the long-term variability of acetylene and ethane in the stratosphere of Jupiter
• A possibly universal red chromophore for modeling color variations on Jupiter
• Spatial distribution of Jovian clouds, hazes and colors from Cassini ISS multi-spectral images
• Temperature and composition disturbances in the southern auroral region of Jupiter revealed by JWST/MIRI
• The Origin of Jupiter's Great Red Spot
• The Thermal Structure and Composition of Jupiter's Great Red Spot From JWST/MIRI
• The role of cloud particle properties on WASP-39b transmission spectrum based on JWST/NIRSpec observations
• archNEMESIS: an open-source Python package for analysis of planetary atmospheric spectra