These images are based upon the randomly selected time step 18 UTC on 2008-04-04. The layer is always the one at the lowest altitude because only this is subjected to downscaling.

Fig. 1: Gravimetric humidity as supplied by the COSMO model: The coarse data.

Downscaled data

In the case of gravimetric humidity, there is no Schomburg rule, so the downscaling is limited to spline interpolation (cf. Fig. 2). Figures 3, 5, and 5.1 are missing for this reason.

Fig. 2: Gravimetric humidity after spline interpolation.

Fig. 4: Gravimetric humidity after spline interpolation and subsequent upscaling back to the coarse grid.

Fig. 4.1: Gravimetric humidity bias after spline interpolation, on the coarse grid. The axis limits have changed.

As the bias is 10^7 times smaller than the ordinary fields above, it can safely be attributed to only numerical fluctuations.