3. Results: dust-free case up previous next
3.c. Surface stress (1)

Figure 5: Diurnal change of the magnitude of surface stress from LT=06:00 to 18:00. Blue and light blue lines indicate the maximum value and horizontal mean value, respectively. Orange and red lines indicate the minimum and the maximum values of the threshold surface stress required to raise dust from the surface (Greeley and Iversen, 1985).


Figure 5 shows the diurnal change of the magnitude of surface stress calculated from the horizontal wind velocity at the hight of 1.5 m, which is the lowest level of the model. The maximum value of the horizontal mean surface stress is around 0.005 Pa. However, the maximum value of surface stress at each grid point reaches 0.03 to 0.04 Pa. According to Greeley and Iversen, 1985), these values are of the order of the threshold surface stress which is required to raise dust from the surface.


A numerical simulation of thermal convection in the Martian lower atmosphere.
Odaka, Nakajima, Ishiwatari, Hayashi,   Nagare Multimedia 2001
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