Localized Convection in Sputnik Planitia, Pluto

Abstract The cellular plains on Sputnik Planitia (SP) are thought to originate from convection in the nitrogen ice layer that fills the basin. Whereas the cells toward the center of SP's cellular plains are wider and interconnected—features explained by vigorous convection—the cells near the margins are smaller and less contiguous, with some appearing completely isolated. We propose that these isolated cells are surface expressions of localized convection—a rare planform in which stable thermal plumes can form in isolation from one another. Numerical simulations of convection using experimentally determined flow laws for power‐law creep in nitrogen ice show that for typical parameters of SP, the viscosity contrasts across the layer are sufficiently high for localization to occur. The diameter of the isolated cells provides constraints on the thickness of the nitrogen ice layer, the surface topographic anomaly, surface heat flow, and surface velocities associated with the localized cells.