During T-REX, a number of models were run in real-time to support the field campaign. These high-resolution models were run at similar resolution and yet showed very different characteristics to the explicit mountain wave and downslope windstorm forecasts.
The intercomparison objective is to explore the sensitivity of flow over steep terrain to model formulation for strong forcing conditions such as mountain waves and rotors.
Evaluate benefits of higher-order accurate numerical methods
Gain insight into the behavior of various numerical methods for flow over real topographic obstacles.
Initial sounding based on 21Z 25 March 2006 upstream sounding (MGAUS) and 00Z 26 March Oakland sounding
2D configuration for models
Δx = 1 km, Δz = 200 m (401×134)
Stretched grid in vertical below 800 m
6 simulations with various terrain heights
Baseline: hm= 100 m, free slip
T = 250 K, U = 20 m s-1
Case 1: hm= 1000 m, free slip
Case 2: hm= 2500 m, free slip
Case 3: hm= 2500 m, no slip, z0 = 10 cm
Case 4: Sierra terrain, free slip
Case 5: Sierra terrain, no slip, z0= 10 cm
for more information look on the T-REX project page.