THE MARS PATHFINDER ATMOSPHERIC STRUCTURE INVESTIGATION METEOROLOGY (ASI MET) EXPERIMENT/

The Mars Pathfinder atmospheric structure investigation/meteorology (A SI/MET) experiment measured the vertical density, pressure, and temper ature structure of the martian atmosphere from the surface to 160 km, and monitored surface meteorology and climate for 83 sols (1 sol = 1 m artian day = 24.7 hours). The atmospheric structure and the weather re cord are similar to those observed by the Viking 1 lander (VL-1) at th e same latitude, altitude, and season 21 years ago, but there are diff erences related to diurnal effects and the surface properties of the l anding site. These include a cold nighttime upper atmosphere; atmosphe ric temperatures that are 10 to 12 degrees kelvin warmer near the surf ace; light slope-controlled winds; and dust devils, identified by thei r pressure, wind, and temperature signatures. The results are consiste nt with the warm, moderately dusty atmosphere seen by VL-1.