Determining the zero-plane displacement height of complex surface from the length scale of vertical velocity power spectra measured in surface layer
This article analyzes the characteristics of turbulence spectra by using multi-layer turbulence observation data from the SORPES observation station at the Xianlin Campus of Nanjing University,located in the suburbs of Nanjing.Based on the criterion that the length scale corresponding to the vertical velocity power spectra peak under unstable conditions during the day(the ground height),the feasibility of this method used to determine the zero plane displacement of complex underlying surfaces was explored.Statistics show that the shapes of probability distribution of the length scales of the spectral peak at the two heights are similar,and the length scale with the maximum probability can be regarded as the height from the level of zero-plane displacement.The zero-plane displacement heights derived from the measurement data at the two levels are almost the same.Additionally,the zero-plane displacement height is also determined by using the relationship between the vertical velocity variance and stability parameter.Results show that the zero-plane displacement heights derived the two methods are close to each other.
complex terrainzero-plane displacement heightvertical velocity power spectravertical velocity variance
万方数据
维普
