Phase II Final Report - NASA's Institute for Advanced Concepts

Planetary Exploration Using Biomimetics
An Entomopter for Flight on Mars
Figure 2-11: Atmospheric Temperature Variation Throughout a Day (Pathfinder Data)
[227]
By evening, the thermal convection subsides and the instability in the atmosphere is diminished.
The atmosphere becomes stable again due to surface cooling during the night. Any major nighttime
temperature fluctuations are caused by downslope winds that disturb the surface boundary
layer.
2.4.3 Dust Storms and Wind
The wind at or near the surface can range from 2 to 7 m/s, (based on Viking Lander data). These
winds have a strong diurnal and seasonal variation in both direction and magnitude. Wind
speeds of up to and possibly greater than 50 m/s will occur above the surface boundary layer;
this surface boundary layer is estimated to extend tens of meters above the surface. Preliminary
estimates of the Pathfinder wind data suggest that wind speeds were comparable with or lower
than those measured by Viking Lander-1 at the same time of year. Speeds were generally less
than 5 to 10 m/s, except during the passage of dust devils, and were often less than 1 m/s in the
morning hours. This may be consistent with the lower slope at the Pathfinder site. [227]
For a one-month period, pathfinder data shows that wind direction generally rotated in a clockwise
manner through a full 360°. Winds were consistently from the south in the late and early
morning and then rotated steadily through west, north and east during the day. The wind direction
at night was very consistent but became more variable throughout the day. The wind direction
is shown in Figure 2-12.
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Phase II Final Report