Research Projects

Credit: Dotted Yeti/Shutterstock

Venus

Venus has a thick, dry and acidic atmosphere. This atmosphere is considered as a result of the runaway process in the past. However, what caused and contributed to this runaway process and why the Venus atmosphere evolved in a different path from that of Earth, the twin of Venus, are still unsolved problems.

The current atmosphere of Venus can provide useful hints for its past. The Venus atmosphere has complex photochemistry, globally-covering sulfuric acidic clouds and unique circulation patterns (e.g., superrotation and SS-AS). Understanding the origins of these atmospheric processes and the interaction among them is the first step for us to use present-day atmosphere to illuminate its unknown and interesting history.

My current work involves the interaction between photochemistry and dynamics in multiple dimensions and the cloud formation and its coupling with dynamics on Venus.

Related publications:

Shao, W. D., Zhang, X., Mendonça, J., Encrenaz, T. (2021). Local-time Dependence of Chemical Species in the Venusian Mesosphere, under review.

Shao, W. D., Zhang, X., Bierson, C. J., & Encrenaz, T. (2020). Revisiting the sulfur‐water chemical system in the middle atmosphere of Venus. Journal of Geophysical Research: Planets, 125(8), e2019JE006195.

Credit: NASA and JPL

Enceladus

The energy budget of Enceladus in the present day is still a problem. From Cassini's measurements, Enceladus is inferred to have a global subsurface ocean. However, the existence of this ocean suggests that the ice shell is losing heat in a large rate. So is Enceladus in thermal equilibrium? If so, what is the heat source to maintain this equilibrium?

The tidal dissipation is considered as a good candidate for the heat source if Enceladus is in thermal balance. My research aims to understand how this tidal dissipation inside the satellite contributes to its energy budget. My recent study focuses on how forced librations affect the tidal dissipation and also the thermal state of Enceladus.

Related publications:

Shao, W. D., Nimmo, F. (2021). An Investigation of Libration Heating and the Thermal State of Enceladus’s Ice, under review.