Shanghai Astronomical Observatory Astrophysics Colloquium

Title：Equatorial eastward jet in Jupiter's atmosphere reveal the signatures of the deep helium rain layer

Speaker: Yuchen Lian (SHAO)

Time：3:00 pm Feb.27th (Thursday)

Tencent Meeting：429-1540-0486 password: 6360

Location: Lecture Hall, 3rd floor

Abstract：

Alternating zonal jet winds are among Jupiter's most spectacular atmospheric features. The jets, coupled with Jupiter's interior, help reveal the signatures of deeper structure and dynamics. Despite decades of efforts, even after the Juno mission, atmospheric models face challenges in accurately accounting for the observed characteristics of the jets; for example, the depth of the jets remains unclear, the number of belts and zones is not explained, and a strong and wide eastward equatorial jet is not well understood. Here, we show novel and perhaps more realistic simulations of Jupiter's alternating atmospheric jets with depth and strength, including multiple off-equatorial belts and zones and a strong equatorial eastward jet with a maximum wind speed of approximately 100 $\mbox{m}/\mbox{s}$. It is found that the equatorial eastward jet must be associated with zonal inhomogeneities, which can be a ``spooky action'' of Jupiter’s deep interior, by upward propagating disturbance originating from the magnetohydrodynamic waves in the deeply embedded stable helium rain layer. Our results infer that, generally, for an internally heated giant planet, the formation of an equatorial eastward atmospheric jet depends on the presence of an internal stable layer. We generalize a promising explanation of the contrasting dynamics between Jupiter and Saturn (equatorial eastward atmospheric jets, with internal stable layers) and Uranus and Neptune (equatorial westward atmospheric jets, without internal stable layers). Therefore, atmospheric circulation might be a handy approach to probing the internal structure of giant planets.

CV：

Dr. Yuchen Lian is a postdoctoral researcher at Shanghai Astronomical Observatory, specializing in planetary atmospheric dynamics following a Ph.D. in Physical Oceanography from Peking University. His research focuses on unraveling large-scale circulation mechanisms, wave-mean flow interactions, and energy transport in diverse planetary systems, including Jupiter, Venus, and exoplanets, through high-resolution numerical modeling (GCMs). He diagnoses atmospheric wave activity in Venusian and Jovian winds, and published findings The Astrophysical Journal (ApJ) and other journal. His work bridges theoretical dynamics with observational constraints to decode atmospheric evolution across planetary systems.

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