gas resulting / sub-slab gas / gas flow / pure gas / net vertical gas velocity / end-member solutions / solar and thermal energy / sublimation gas flux / transfer energy / gas velocity / condensation site / gas falls / local gas bubble / sub-slab lateral gas velocity / streaming gas / gas velocities / solar energy / sealed gas envelope / thermal energy / sublimation gas / imaging / predominant gas / steady state solution / gas phase / non-condensing gas / /