Abstract
Mars’ polar layered deposits record critical information about its
climate history. Here, I numerically model formation of alternating
layers of CO2 and H2O ice in Mars’ south polar Massive CO2 Ice Deposit
to reconstruct its H2O ice depositional history over the past 510
thousand years. Statistical analyses of ~10^9 model
runs favor a best-fit historical H2O ice deposition function that
exponentially decreases with obliquity, with ~1, 0.1,
and 0.01 mm yr^-1 rates for 20, 24, and 28 deg. obliquity,
respectively. Recovery of a south polar
H2O-ice-deposition-versus-obliquity function is novel and important for
elucidating Mars’ global water cycle; previous south polar layer
analyses were limited to calculation of net average deposition rates
over millions of years.