[PCG25-P03] Time response of the self-regulation of H and O escapes from Mars
Keywords:Mars, Atmospheric evolution, water
Here we study time-dependent responses of self-regulation system on different atmospheric conditions. We use a 1D time-dependent photochemical model for various atmospheric conditions and parameters, such as atmospheric CO2 pressure, vertical temperature profile and O escape rate.
We find that timescale of the self-regulation is mainly determined by O escape flux and the CO2 pressure. The timescale is inversely proportional to O escape flux, whereas it increases nonlinearly as the CO2 pressure increases. Our calculations also show that when CO2 pressure drops from the current Martian converged condition, H escape flux increases on a timescale of several days and returns to the twice of O escape flux on a timescale of a hundred thousand years. It implies that seasonal drops of the atmospheric pressure due to the CO2 polar ice cap may contribute to the variation of H escape flux. The effect of vertical temperature profile on self-regulation will also be discussed.