Scientific objective A-2: planetary boundary layer and surface-atmosphere interactions

Surface in situ observations characterise the PBL phenomena and the surface-atmosphere interactions at the landing sites. The large number of landers and global coverage allow for selection of landing sites with widely varying surface characteristics. Consequently coarse mapping of on the dependence of the PBL on the surface characteristics can be obtained. Stability, surface fluxes of momentum and heat, and growth of the mixed layer (Tillman et al, 1994) can be estimated from ground and atmospheric temperature (at 2-3 vertical levels), and high time resolution wind data. Humidity measurements may provide important in situ data on seasonal and diurnal variations as well as on the exchange of H2O between the atmosphere and the regolith. Dust devils and their role in dust lifting are monitored through pressure observations and correlating them with imaging results.