Atmospheric and Climate Modeling Research Group is doing advanced numerical modeling of environmental processes of different scales using the high resolution global atmospheric model (HIRAM) and the regional weather research and forecast (WRF) model. Both models use similar mathematical approach (equations are shown on the slide) but global model is applied for the entire sphere and regional focuses on a specific region. This work is based on fluid dynamics, physics, numerical methods, and High Performance Computing. Using HIRAM we conduct pioneering global 25-km (10 times smaller grid spacing than conventional models) resolution simulation to study regional climate in the Middle East, and apply WRF up to 1-km resolution to study dust storms, renewable energy mapping, flash floods, air-quality.