Emerging regional climate change signals for Europe under varying large-scale circulation conditions

Abstract

A large ensemble of regional climate model projections was investigated regarding if and when they show an emergence of significant climate change signals in seasonal temperature and precipitation within Europe. The influence of the North Atlantic Oscillation (NAO), as simulated in the projections, was investigated. In most parts of Europe, the projections indicate robust emergence of temperature change in the first 2 decades of the 21st century, typically earlier for summer than for winter. For precipitation changes, signals generally emerge much later than for temperature. For Europe as a whole, the precipitation signals tend to emerge some 40 to 60 yr later than the temperature signals. In some sub-regions, robust signals for precipitation are not found within the studied period, i.e. until 2100. Some sub-regions, notably the Mediterranean area and Scandinavia, show different behaviour in some aspects compared to the ensemble-based results as a whole. NAO has some influence on the temperature change signals, which emerge earlier in winter for some models and regions if NAO is accounted for. For summer temperatures, the influence of NAO is less evident. Similarly, for precipitation, accounting for NAO leads to an earlier emergence in some regions and models. Here, we find an impact for both summer and winter.

European climate change at global mean temperature increases of 1.5 and 2 °C above pre-industrial conditions as simulated by the EURO-CORDEX regional climate models

“…This finding is in accordance with earlier studies that have also shown different times of emergence of a regional climate change signal (e.g. Giorgi and Bi, 15 2009;Hawkins and Sutton, 2012;Kjellström et al, 2013).…”

“…This is 20 in concert with previous studies showing a similar dependence (e.g. Van Ulden and van Oldenborgh, 2006;Kjellström et al, 2011;Kjellström et al, 2013). Differences in the large-scale circulation over decade-long climate simulations are not necessarily a sign of climate change but rather a manifestation of the large internal variability of the climate system that can be pronounced on a regional scale (e.g.…”

“…Rummukainen, 2010;Sørland et al, 2017). For Europe relatively large data sets of RCM scenarios have previously been put forward within the context of European research projects including PRUDENCE Déqué et al, 2007) and ENSEMBLES (van der Linden et al, 2009;Déqué et al, 2012;Kjellström et al, 2013). In recent years RCMs have been operated in the framework of CORDEX (Coordinated 25 Regional climate Downscaling EXperiment, e.g.…”

How drought severity constrains gross primary production(GPP) and its partitioning among carbon pools in a <i>Quercus ilex</i> coppice?

“…According to global and regional climate models, Mediterraneantype ecosystems (MTEs) will suffer longer and more intense droughts as a result of (1) increasing temperature and decreasing rainfall (Hoerling et al, 2011), (2) a change in largescale circulation conditions (Kjellström et al, 2013), and (3) the persistence of heat wave anomalies (Jaeger and Seneviratne, 2011). In MTEs, drought is already the prevailing constraint on the net ecosystem productivity (NEP) (Allard et al, 2008;Grünzweig et al, 2003).…”

Projected Change—Models and Methodology

“…However, RCM climate change projections are in general still carried out for the atmosphere only, prescribing SST data taken from the driving model Kjellström et al 2013). Consequently, the quality of the prescribed SST/ sea ice data depends on the quality of the global modelling system.…”