Turbulent Fluxes and Evaporation/Sublimation Rates on Earth, Mars, Titan, and Exoplanets

Turbulent fluxes of heat, momentum, and humidity in the atmospheric boundary layer are pivotal to the evolution of geology, weather and climate, and the possibility of life.Here we extend recent advances in calculating these near-surface turbulent fluxes in the Earth's atmospheric boundary layer to any terrestrial planetary body with an atmosphere. These improvements include: (1) incorporating Monin-Obukhov similarity functions that encompass the entire range of atmospheric stability expected on terrestrial planetary bodies, (2) accounting for the additional shear associated with buoyant plumes under unstable conditions, (3) using surface renewal theory to calculate transfer rates within the interfacial layer adjacent to the surface, and (4) explicitly accounting for key humidity effects that become especially important when a volatile is more buoyant than the ambient gas (e.g., on Mars where H2O is lighter than CO2). We validated our model using in-situ data collected on Earth, Mars, and Titan under a wide range of atmospheric stability, pressure, and surface roughness conditions. We find that the model shows up to 5 times better agreement with measurements compared to methods commonly used on Mars. To illustrate the wide range of problems our model can be applied to, we predict sublimation rates from glaciers and sea ice on Snowball Earth, the thickness of lake ice on Mars, dust/sand lifting conditions on Titan, and the lifetime of oceans on potentially habitable exoplanets. Our generalized model can also provide improved estimates of near-surface atmospheric conditions faced by future robotic and human missions to these locations.