Extended Abstract (500K)J1.6
Observations of stratified atmospheric shear-driven turbulence at low and high Richardson numbers
Thorsten Mauritsen, Stockholm University, Stockholm, Sweden; and G. Svensson
We analyze turbulence data from mast-based experiments. The data is organized using the gradient Richardson number, Ri, as dimensionless stability parameter, rather than the widely used Monin-Obukhov normalized height, z/L. Ri has the advantage over z/L of being free of artificial correlations with the data we wish to present.
We used data from six different experiments, including CASES-99, SHEBA, CME04, FLOSS, FLOSSII and a Swedish experiment performed on the coast of the island Östergarnsholm in the Baltic sea. This means that we sample a vast variety of physical environments: Grassland, Arctic sea ice, mountain forest canopy, partially snow covered land and coastal conditions. The total amount is the equivalent of five and a half years worth of stably stratified turbulence data.
Important non-dimensional properties of the turbulence field are presented including the turbulent fluxes of momentum, heat and moisture. These are non-dimensionalized using the turbulent variance. We find that two important regimes exist, the weakly- and very stratified regimes. We find that at Ri<0.1 non-dimensional fluxes are almost constant. At 0.1
Joint Session 1, Stable Boundary Layers 1 (Joint Between 17BLT and 27AgForest)
Monday, 22 May 2006, 8:30 AM-12:00 PM, Kon Tiki Ballroom
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