CONSTRUCTION AND IMPLEMENTATION OF A GRID ADAPTATION METHOD IN A 1D TURBULENCE MODEL

Abstract

Accurate climate modeling results are challenging to achieve with coarse vertical grids. How-ever, using fine-resolution grids with numerous levels can significantly increase the compu- tational costs. Therefore, it is optimal to refine the grid in regions where more grid levels are required while maintaining a coarse grid elsewhere. A method to adapt the grid over time is proposed, refining near regions of interest while keeping the number of levels fixed to control the computational complexity. This method involves a refinement criterion, which yields a grid density profile over the grid’s region and a normalization formula, which takes the grid density and normalizes it, to ensure a specific number of levels and a minimum grid density. The refinement criterion considers the alti- tude, the Richardson number, and the extended liquid water content as factors. The method was tested on the ARM, ASTEX, and GABLS2 cases in the CLUBB (Cloud Layers Unified By Binormals) model. The grid adaptation method refined the grid primarily near cloud regions, particularly the cloud top and the surface. The results demonstrated improvements in the mean profiles for cloud-related variables. Generally, most variables exhibited smoother temporal development compared to a fixed grid, even though the mean profiles remained unchanged. In the GABLS2 case, some degradations were observed using the grid adaptation method, likely due to diffusion during the remapping.