Plot of the month (Dec 2016): land and global precipitation

Plot of the month for December 2016 is from Benoît Vannière, who evaluates hydrological cycle processes in models and their sensitivity to model horizontal resolution.


This figure shows the ratio of land to global precipitation as a function of model resolution (at 50°N). Filled circles show atmosphere-only experiments and open circles show coupled experiments.

  • It is interesting to note that two different behaviours arise depending on model formulation: for finite differences/volumes models (HadGEM3, CAM5-1) the land to global precipitation ratio increases with resolution, whereas it decreases in spectral models (EC-Earth3, EC-Earth3.1, MRI3.2).
  • Coupling does not modify this behaviour.
  • The purple circles stand for two experiments testing the sensitivity to the resolution of orography: the control (top) uses HadGEM3_GA6 on high-resolution N480 grid, the perturbed experiment (bottom) uses the same atmospheric resolution but with low-resolution N96 orography (see the About HRCM page for an illustration).
This is ongoing research.