Abstract
Turbulent organized structure (TOS) above urban canopies has not been clarified. In order to investigate it, we observed the horizontal distribution of TOS at COSMO (Comprehensive Outdoor Scale Model experiment for urban climate). The horizontal dimension of COSMO was 50m x 100m, with 1.5m cubic roughness blocks arranged uniformly. 60 thermo couples and 8 sonic anemometers were arranged.
A new quantitative analysis to characterize the size of TOS has been conducted by using OSIM (Organized Structure Identification Method). OSIM detects the area of large turbulent motion and quantified the span-wise width and the time duration of the motion. In this study, we explained the algorithm of OSIM and applied it to COSMO data.
