[P-PS05] 火星と火星衛星

[PPS05-10] Mars Methane: Can both MSL and TGO Be Correct?

★Invited Papers

*Scot CR Rafkin¹、Alison Bridger³、Jorge Pla-Garcia² (1.Southwest Research Institute 、2.Centro de Astrobiología / INTA / CSIC、3.San Jose State University)

キーワード：Mars, Atmosphere, Methane, Mesoscale Model, Transport, Dispersion

The Mars methane mystery has not yet been resolved. In situ surface detections by the Mars Science Laboratory (MSL) indicate methane background concentrations of ~0.5 ppbv with occasional spikes to O(10-20). In contrast, the Trace Gas Orbiter (TGO) has found no evidence of methane down to threshold detection levels. We utilize high resolution (~3 km grid spacing) mesoscale model simulations with Eularian tracers and forward and backward Lagrangian trajectory modeling driven by the model winds to evaluate the possibility that methane released at the surface could be detected by MSL but not detected by TGO. The complex, 3-D nature of methane transport and diffusion in the atmosphere is clearly revealed. Considering the possibility of rapid near-surface methane destruction, we identify specific cases where both MSL and TGO could be valid. We discuss the likelihood of such events.