Precipitation in the EURO-CORDEX $$0.11^{\circ }$$ 0 . 11 ∘ and $$0.44^{\circ }$$ 0 . 44 ∘ simulations: high resolution, high benefits?

Abstract

Germany, Sweden, Norway, France, the Carpathians, and Spain. A clear result is that the 0.11 • simulations are found to better reproduce mean and extreme precipitation for almost all regions and seasons, even on the scale of the coarser-gridded simulations (50 km). This is primarily caused by the improved representation of orography in the 0.11 • simulations and therefore largest improvements can be found in regions with substantial orographic features. Improvements in reproducing precipitation in the summer season appear also due to the fact that in the fine-gridded simulations the larger scales of convection are captured by the resolved-scale dynamics. The 0.11 • simulations reduce biases in large areas of the investigated regions, have an improved representation of spatial precipitation patterns, and precipitation distributions are improved for daily and in particular for 3 hourly precipitation sums in Switzerland. When the evaluation is conducted on the fine (12.5 km) grid, the added value of the 0.11 • models becomes even more obvious.

Mean and extreme precipitation over European river basins better simulated in a 25 km AGCM

“…At the same time, the 0.11 • simulations better reproduce spatial precipitation patterns (Casanueva et al, 2016) and this improvement is seen both for mean and moderately heavy (95 and 97.5 daily percentiles) precipitation (Fantini et al, 2016;Prein et al, 2016). These benefits due to high resolution are also seen when the evaluation is carried out on the coarser 0.44 • grid and are largely attributed to the better representation of orography in the higher resolution RCMs (Prein et al, 2016).…”

“…Evaluating these simulations with respect to their representation of precipitation in Europe shows that for seasonal mean quantities averaged over large European subdomains no clear benefit of an increased spatial resolution can be identified (Kotlarski et al, 2014). At the same time, the 0.11 • simulations better reproduce spatial precipitation patterns (Casanueva et al, 2016) and this improvement is seen both for mean and moderately heavy (95 and 97.5 daily percentiles) precipitation (Fantini et al, 2016;Prein et al, 2016). These benefits due to high resolution are also seen when the evaluation is carried out on the coarser 0.44 • grid and are largely attributed to the better representation of orography in the higher resolution RCMs (Prein et al, 2016).…”

Evaluation of CORDEX-Arctic daily precipitation and temperature-based climate indices over Canadian Arctic land areas

“…In a recent analysis of daily precipitation indices using CCCmaCanRCM4 simulations at 0.22° and 0.44° resolutions, but integrated over the North-America CORDEX domain, Diaconescu et al (2016) also found that the simulation at 0.22° resolution was more effective for some summertime indices over Canada south of 60°N, but not for winter-time indices, the skill in simulating the winter indices being already good in the 0.44° version of the model. Prein et al (2016) also showed that added value can be obtained in higher resolution simulations for regions with complex orography.…”

Regional Climate Projections

“…Heavy precipitations are usually small-scale phenomena, and recent studies show a clear improvement in the statistics of such phenomena (Prein et al 2016;Giorgi et al 2016), in particular over mountainous areas, when using high-resolution simulations (e.g. 12 km as in EURO-CORDEX).…”