Mars' Atmosphere from the Surface

Surface station measurements at Mars are rare. From 1976 and into the early 1980's, two Viking Lander stations collected temperature, pressure and wind data on a somewhat regular hourly basis. These data were extremely useful not only for their novelty, but also because the stations sampled one tropical and one extratropical location (VL1 and VL2, respectively). There then occurred a long gap until the Mars Pathfinder mission of 1997. This system included a slightly improved set of observations in the sense of yielding a 3 point profile of temperature in the lowest meter of the atmosphere. The use of solar power and limited data rates meant that data was not collected hourly and the mission did not last for a full Martian year. The highly popular Mars Exploration Rovers did not carry a meteorology station. However, the thermal emission spectrometer allowed profiles of air temperature and associated ground temperature to be retrieved. These data yielded greater insight into the extremely superadiabatic nature of the lower daytime boundary layer. In 2008, the Phoenix Lander carried a Viking-like meteorology package to the high northern latitudes accompanied with a LIDAR. This mission provide the first opportunity to sample the water cycle near the surface, yielding clear demonstration of surface exchange, vertical mixing, and precipitating water ice. Like Mars Pathfinder, the solar-powered Phoenix lasted less than a Martian year. At the time of writing, the Mars Science Laboratory (MSL) has just arrived at Mars. It carries the Rover Environmental Monitoring Station, which also yields a Viking-like dataset, with the addition of humidity and UV sensors. Unlike all prior landing sites, the MSL Gale Crater site has significant topography and distinct mesoscale flows are expected. In this presentation, we will summarize the results and methods of surface station observations at Mars, their influence upon our understanding of micro, meso, and synoptic scale circulations, and some thoughts for future observing systems.