Exploring Regional Climate of the Euro-Mediterranean Using a
Variable-Resolution Configuration of the Global Community Earth System
Model (VR-CESM)
Abstract
A Variable-Resolution, global configuration of the Community Earth
System Model (VR-CESM) in which the atmosphere and land are the only
active components is employed to investigate the climate of the
Euro-Mediterranean region. Two variable-resolution grids with
regionally-refined resolutions of 0.25° and 0.125° over the study
domain, respectively, are used. The fidelity of these VR-CESM
simulations is evaluated considering the near-surface air temperature
and precipitation fields for the 2000-2014 period in comparison to
available observation-based datasets and those of a coarse resolution
(quasi-uniform 1°) control simulation. Our analysis shows that, as a
global model, VR-CESM is a promising alternative to regional climate
models to advance our understanding of the Euro-Mediterranean climate.
The improvements obtained are mainly related to a better representation
of the complex topography of the region with higher resolution.
Increasing the regional resolution to 0.25° generally yields
considerable improvements over the control simulation, however some
persistent biases remain. Doubling the highest resolution to 0.125°
leads to only modest improvements, primarily in the representation of
small-scale processes including representation of extreme events that
are of substantial relevance for the present and future of the regional
climate.