Volatile transport on inhomogeneous surfaces: II. Numerical calculations (VT3D)

TL;DR

This paper introduces VT3D, a new numerical model that efficiently simulates seasonal volatile transport on inhomogeneous icy surfaces like Pluto and Triton, accounting for latitude and longitude variations.

Contribution

The paper presents VT3D, a novel numerical model that improves computational speed and accuracy for simulating volatile and thermal evolution on icy worlds with variable surfaces.

Findings

VT3D enables faster simulations of seasonal volatile transport.

The model accurately handles transitions between global and non-global atmospheres.

VT3D incorporates energy and mass conservation with stable time-stepping.

Abstract

Several distant icy worlds have atmospheres that are in vapor-pressure equilibrium with their surface volatiles, including Pluto, Triton, and, probably, several large KBOs near perihelion. Studies of the volatile and thermal evolution of these have been limited by computational speed, especially for models that treat surfaces that vary with both latitude and longitude. In order to expedite such work, I present a new numerical model for the seasonal behavior of Pluto and Triton which (i) uses initial conditions that improve convergence, (ii) uses an expedient method for handling the transition between global and non-global atmospheres, (iii) includes local conservation of energy and global conservation of mass to partition energy between heating, conduction, and sublimation or condensation, (iv) uses time-stepping algorithms that ensure stability while allowing larger timesteps, and (v) can include longitudinal variability. This model, called VT3D, has been used in Young (2012), Young (2013), Olkin et al. (2015), Young and McKinnon (2013), and French et al. (2015).