Global high resolution versus Limited Area Model climate change projections over Europe: quantifying confidence level from PRUDENCE results

Abstract

Four high resolution atmospheric general circulation models (GCMs) have been integrated with the standard forcings of the PRUDENCE experiment: IPCC-SRES A2 radiative forcing and Hadley Centre sea surface temperature and sea-ice extent. The response over Europe, calculated as the difference between the 2071–2100 and the 1961–1990 means is compared with the same diagnostic obtained with nine Regional Climate Models (RCM) all driven by the Hadley Centre atmospheric GCM. The seasonal mean response for 2m temperature and precipitation is investigated. For temperature, GCMs and RCMs behave similarly, except that GCMs exhibit a larger spread. However, during summer, the spread of the RCMs—in particular in terms of precipitation—is larger than that of the GCMs. This indicates that the European summer climate is strongly controlled by parameterized physics and/or high-resolution processes. The temperature response is larger than the systematic error. The situation is different for precipitation. The model bias is twice as large as the climate response. The confidence in PRUDENCE results comes from the fact that the models have a similar response to the IPCC-SRES A2 forcing, whereas their systematic errors are more spread. In addition, GCM precipitation response is slightly but significantly different from that of the RCMs

An assessment of temperature and precipitation change projections over Italy from recent global and regional climate model simulations

“…The PRUDENCE experiments can be considered as the most up-to-date ensemble of climate change projections over Europe and the main results of the project are described in a special issue of Climatic Change published in May 2007. In particular, the general conclusions from the PRUDENCE ensemble can be found in Christensen and , Jacob et al (2007) and Déqué et al (2005Déqué et al ( , 2007.…”

“…During the last two decades or so, mostly as a result of a series of European projects, a number of climate change simulations over Europe have been completed by several groups using a grid spacing of about 50 km (e.g. Giorgi et al, 1992Giorgi et al, , 1997Giorgi et al, , 2004bJones et al, 1997;Rotach et al, 1997;Machenhauer et al, 1998;Räisänen et al, 1999Räisänen et al, , 2004Christensen and Christensen, 2003;Kjellström, 2004;Schär et al, 2004;Semmler and Jacob, 2004;Déqué et al, 2005Déqué et al, , 2007, which allows a crude but realistic description of the Italian territory. In particular, as part of the most recent European Union (EU) project, PRU-DENCE ten RCMs were used to produce climate change scenarios over the European region for two different GHG emission scenarios of IPCC (2000).…”

Climate change in the next 30 years: What can a convection-permitting model tell us that we did not already know?

“…Note that for the selected future period, i.e. 2021-2050, the climate change signal is weaker than for the period 2071-2100 commonly used in climate change studies (Giorgi et al 2004;Déqué et al 2005;Déqué et al 2007;Boberg et al 2009). The downscaling is performed for two 33-year periods, and the first 3 years are considered spin-up time and therefore not included in the analysis.…”

The Regional Climate Change Hyper‐Matrix Framework

“…The RCD model configuration and approach uncertainties also contribute substantially to the overall RCCP uncertainty. These Déqué et al [2005].…”