Predicting migration rates and windspeeds from Martian barchan dune geometries

This study investigates whether the geometry of Martian barchan dunes can be used to estimate sediment flux, migration rates, and local wind conditions. Time-separated HiRISE imagery from five Martian dune fields was analyzed to measure dune geometries and crest displacements over multi-year timescales. From these measurements, migration rates and sediment volume fluxes were derived for 214 dunes across 5 dunefields.

An analytics terrestrial dune migration model was adapted to Martian environmental conditions by incorporating Martian values for gravity, atmospheric density, sediment density, grain size, and transport efficiency. Relationships between dune geometry, migration rate, sediment flux, and wind shear were subsequently predicted and validated with measurements.

The results show a positive correlation between stoss-side gradient and volume flux across all investigated dune fields. These relationships are consistent with trends previously observed for terrestrial barchan dunes, indicating that similar geometric controls on dune migration operate under Martian conditions. However, Martian dunes exhibit sediment fluxes approximately one order of magnitude lower than terrestrial dunes with comparable stoss-side gradients, reflecting the influence of Mars’ distinct atmospheric and gravitational environment.

Migration rates predicted from dune geometry reproduce the observed order of magnitude of dune movement, despite significant scatter for individual dunes caused by slow migration rates, limited measurable displacement, and uncertainties in environmental parameters. Using the derived sediment fluxes and dune geometries, local wind shear conditions were additionally estimated, suggesting that orbital dune observations may be used as proxies for atmospheric forcing on Mars or other planets.