Regional Climate Downscaling

Global climate models compute temperature and rainfall on a grid of cells — and every point inside a cell gets the same averaged elevation, no matter how much real terrain varies underneath. This simulator builds one fixed patch of coastline and mountains, then shows three views of it side by side: the coarse GCM grid (blocky, terrain-blind), a downscaled reconstruction that reapplies the coarse model's large-scale forcing to the real fine-resolution terrain, and the observed-truth reference computed directly from full terrain detail. Change the grid resolution, terrain relief and wind direction, and watch the RMS error against the observed truth shrink as resolution increases and downscaling recovers local detail — with rainfall settling to a nonzero residual error that temperature does not.