Speculations on Orbital Forcing of Sublimation from the Polar Caps

Calculation of the periodic variations in the martian orbital parameters by Ward and subsequent refinements to the theory have inspired numerous models of variation of the martian water cycle. The limitations of models such as this can not be overstated. Albedo, for example, has a much greater influence on temperature than orbital forcing, and seems to be linked to insolation, possibly via its influence on dust transport. To make further progress, either new constraints must be identified, or additional clues must be obtained from remote sensing and in situ exploration.