Assessing Bias Corrected Daily Precipitation Data with Special Focus on
Precipitation Climate Indices Using an Ensemble of High-Resolution
EURO-CORDEX and Med-CORDEX Simulations for the Carpathian Region
Abstract
This study aims to give a brief overview of an ensemble of regional
climate model (RCM) simulations with bias correction for daily
precipitation for the Carpathian Region located in Central/Eastern
Europe. Within the international initiation called the COordinated
Regional Downscaling Experiment (CORDEX) EURO-CORDEX and Med-CORDEX
provide RCM simulations targeting Europe as a whole or in a part at the
grid resolutions of 0.44o (~50 km) and 0.11o
(~12 km). The ensemble of RCMs provides a huge amount of
data, which are however prone to biases compared to high resolution
observations. Percentile-based bias corrections of the daily
precipitation output of EURO-CORDEX and Med-CORDEX RCM ensemble at a
common 0.11o × 0.11o horizontal grid resolution are performed based on
the high-resolution, high-quality observational dataset: CARPATCLIM. The
region covered by the CARPATCLIM dataset can be considered as the
Carpathian Region for which the RCM ensemble (consisting of total six
members at 0.11o resolution) of a historical period (1976-2005) and
under the Representative Concentration Pathway 8.5 over two future time
slices (2021-2050 and 2070-2099) are assessed. The present study focuses
on precipitation climate indices over the entire Carpathian Region and
two subregions representing high- and lowlands within the target region.
The analyzed indices are: frequency of rainy days (RR1, days with a
total rainfall of at least 1 mm), heavy precipitation days (RR10, days
with a total rainfall of at least 10 mm), highest daily precipitation
(RX1), maximum consecutive dry days (CDD, the duration of the longest
period with < 1 mm total daily precipitation), maximum
consecutive wet periods (CWD, the duration of the longest period with
> 1 mm total daily precipitation). The key findings are as
follows: (1) the influence of orography on seasonal precipitation change
is evident throughout the analyzed periods, (2) precipitation change
holds an unequivocal seasonality as most models estimate significant
winter (DJF) precipitation increase (~30%), while in
general drier (~20%) summers (JJA) are projected over
most part of the Carpathian Region by the end of the 21st century, (3)
over the subregions RR10 shows a clear signal of increase in all seasons
(10-50%), except summer (~-15%), while RX1 shows
increase in all seasons.