大気中の小規模な渦に及ぼす地表面粗度の影響に関する実験

Abstract

The effects of surface roughness on the characteristics of small scale atmospheric vorticessuch as tornadoes are investigated based on a laboratory experiment. Diameter of the vortices, which increases with the swirl ratio, was found to be larger for larger roughnesses. For largeswirl ratios, however, the differences are small. The height at which the maximum wind speedappears varies from the layer very close to the surface to the higher levels as the surface rough-ness increases. Radial distance at which the maximum velocity appears does not vary widelywith roughness.