Influences of Non‐Oberbeck–Boussinesq Effects on Tracer Transport in Icy Ocean Worlds
Name
JGR Planets - 2025 - Wang - Influences of Non‐Oberbeck Boussinesq Effects on Tracer Transport in Icy Ocean Worlds.pdf
Description
Published version
Size
2.23 MB
Format
Adobe PDF
Checksum (MD5)
8db300f9a4b2f734db9af0d7f2f007d9
Author(s)
Wang, Shuang
Kang, Wanying
Date Issued
July 14, 2025
Journal
Journal of Geophysical Research: Planets
Publisher
Wiley
Citation
Wang, S., & Kang, W. (2025). Influences of non-Oberbeck–Boussinesq effects on tracer transport in icy ocean worlds. Journal of Geophysical Research: Planets, 130, e2024JE008892.
Version
Final published version
Abstract
The subsurface oceans on icy satellites are potentially habitable. To understand their habitability,we need to know how tracers with various lifetimes distribute. Convection is the main vehicle for tracertransport, and we expect convection on icy satellites to differ from regular rotating convection, because aspressure increases, water's thermal expansivity can vary by orders of magnitude or even reverse sign nearfreezing point. Any variation of fluid properties would break the Oberbeck–Boussinesq approximation, leadingto non‐Oberbeck–Boussinesq (NOB) effects, measured by a coefficient ϵ. In this work, we identify twocompeting impacts of NOB effects on tracer transport. The first promotes overall upward tracer transport at ϵ2‐order, while the second enhances transport near the bottom source but inhibits transport further up at ϵ3‐order. Inweakly nonlinear regime, the former effect dominates, causing more tracers reaching the ice shell. While instrongly nonlinear regime, the latter effect dominates, reducing tracer concentrations near the ice shell. Byvarying particle lifetimes, we find that NOB corrections are most pronounced when particle lifetime iscomparable to the timescale of upward tracer transport. Additionally, when NOB effects are strong enough tocreate a stratified layer in the upper part of the ocean, tracer transport into the stratified layer is set by energetics.These effects are expected to prolong the transport timescale of chemical tracers or biosignatures from theseafloor to the ice shell on icy satellites.
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
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Creative Commons Attribution
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DOI of Published Version
https://doi.org/10.1029/2024JE008892
