Planetary Lunch Seminar (PLS) – Huazhi Ge (USCS)

Jupiter as an air conditioner: how giant planets’ weather tells a story from the outside in

Abstract: Jupiter is the most massive planet in the solar system. Its weather layer possesses iconic banded circulations and is covered by thick clouds with various colors. Jupiter still undergoes Kelvin-Helmholtz contraction and slowly releases its internal energy into space through emission. Traditional theory suggests that Jupiter’s weather layer is part of a fully convective zone and thermal convection connects Jupiter’s interior and radiative zone. Combining the recent observations and nonhydrostatic cloud-resolving simulations, I will show this picture is oversimplified, and Jupiter’s weather layer is only partially convective. Cloud-forming species are heavier than the background hydrogen-helium mixtures in giant planets. The condensation of water, the most abundant cloud-forming species, causes a molecular weight gradient and disconnects the deep atmosphere and upper weather layer. Thus, thermal convection is turned off. Instead, latent heat flux relates the heat flow in the deep atmosphere to the upper weather layer. The condensation of water also leads to a persistent stable layer, which acts as the compressor of an air conditioner, and a superadiabatic temperature structure. I will show the implications for giant planets’ evolution, interior structure, and atmospheric dynamics. The result from this work will help us understand the current observations from the ongoing Juno mission and look ahead to the future Uranus mission.

About this Series: The MIT Planetary Lunch Seminar [PLS] is a weekly seminar series organized within the EAPS department. Colloquia topics span the range of research interests of the department’s planetary sciences research program. The seminars take place on Tuesdays from 12:30–1:30 pm, unless otherwise noted (term-time only). Speakers include members of the MIT community and visitors. Talks are intended to appeal to graduate students, postdocs, research scientists, and faculty with a background in planetary science. For more information and Zoom password contact: planetary-org@mit.edu.