final_program_abstracts[1]

11 IMSC Session Program
A RCM bias correction method for climatic indices expressed
in a daily based frequency applied to temperature projections
of the North Iberian Peninsula
Wednesday - Parallel Session 5b
Iratxe González and Julia Hidalgo
Environment Unit., LABEIN – Tecnalia, Spain
This study focuses on the fundamental aspect of the Regional Climate Models (RCM)
temperature validation. Current bias correction methods are discussed and a
methodology is proposed for the indices based on a daily frequency as heat and cold
waves, or frost episodes. The methodology proposed is applied to the two meters
temperature projections in the North Iberian Peninsula from six RCM of the EU-FP6
ENSEMBLES project. Several standardized indices from the EU-FP5 STARDEX
project are used to depict the extremes events during summer and winter seasons for
present (1961-1990) and future projections (1991-2100). Using Empirical Orthogonal
Function analysis regional historic series, from observations and models, and
projections from RCM are obtained for the Basque Country Region situated in the
north of Spain. The selected models generally overestimate the observed extreme
temperatures, both in summer and in winter seasons, with a big influence depending
on the Global Climate Model that drives the RCM. Once the correction methods
applied the standard deviation between models is 4ºC in wintertime and 5ºC in
summertime. The overall tendency due to maximum and minimum threshold
temperature indicates an increase of 3ºC up to 2100. Moreover, from 2020 the
temperature grows faster showing more frequent and longer-term duration heat
waves, from 10% of the days in summer up to 50% days at the end of the century,
while the number of frost days decreases and cold waves become more rare until their
disappearance in the first third of the century.
Abstracts 171