[AAS01-P07] A scale-aware PBL scheme: for the unified simulation in mesoscale and global circulation models
Keywords:scale-aware , PBL scheme, high resolution simulation
The results show that, in terms of the profiles of the area mean values and sub-grid heat/momentum flux, scale-aware UWnew and ShinHong schemes perform the best at “Gray zone” scales among all the schemes (including UWnew, UW, ShinHong, MYNN2.5, YSU, BouLac). And UWnew scheme shows more rational results in the PBL simulation compared with UW scheme. To specify the performance of UWnew scheme in the simulation at “Gray zone” scales, four simulations with different horizontal resolutions were launched using UWnew and UW schemes. In the case of “Gray zone” scales, the profiles of sub-grid heat/momentum flux from the UWnew simulation is smaller than that of the UW scheme. This is mainly resulted from the reduced turbulent heat/momentum exchange coefficient values in the PBL. The weakened vertical flux confirms that the UWnew scheme improves the simulation of the physical process at “Gray zone” scales in which the process is partly resolved and partly parameterized.