Windblown Dust on Venus
Windblown Dust on Venus
复制标题
金星上的风吹尘埃
DOI：
10.1175/1520-0469(1975)032
复制
发表时间：
1975
影响因子：
3.1
通讯作者：
C. Sagan
中科院分区：
文献类型：
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作者：
C. Sagan
在金星表面启动颗粒运动所需的门槛摩擦速度u*0为1-2厘米S−1。有效直径小于30或40微米的颗粒将被这样运动并悬浮在运动门槛处。如果有表面粘聚力，预计会出现u*0的小直径转折。这些u*0的值需要地面边界层以上的速度>；0.3m S−1才能使颗粒在表面上运动。理论论证和金星8号的多普勒测量表明，金星8号着陆点(S 10°)不应该扬起沙尘，而应该在更高的纬度扬起。携带到几十公里高度的尘埃将被输送到整个星球，并可能对太阳能沉积、大气环流和云生色团问题做出重要贡献。然而，Venera8光度计的测量和合理的地表物质的低反照率意味着在10°S有一个晴朗的低层大气，尽管事实是在高纬度扬起的沙尘应该继续存在。
Abstract The threshold frictional velocity u*0 necessary to initiate grain movement on the Venus surface is 1–2 cm s−1. Particles smaller than 30 or 40 µm in effective diameter will be so moved and suspended at the threshold of movement. A small diameter turnup in u*0 is expected if there is surface cohesion. These values of u*0 require velocities >0.3 m s−1 above the surface boundary layer for grain motion on the surface. Theoretical arguments and Venera 8 Doppler measurements suggest marginally that dust should not be raised at the Venera 8 landing site (10°S), but should be raised at higher latitudes. Dust carried to tens of kilometers altitude will be transported over the entire planet and may make important contributions to the solar energy deposition, general circulation, and cloud chromophore problems. However, the Venera 8 photometer measurements and the low albedo of reasonable surface materials imply a clear lower atmosphere at 10°S, despite the fact that dust raised at high latitudes should con...