European regional climate change: A human signal?

Aims What are the causes of recent changes in European climate?

Observed Datasets Two gridded precipitation datasets from GPCC. Global at resolution of 1x1 –vn –VASCLIMO More attention paid to homogeneity CRUTEMP3 -- land temperature record at resolution of 5x5. EWP – England and Wales Precipitation CET – Central England Temperature

Regions Average Precipitation (mm/month) for Europe during Shown are regions used for study. Med Western Europe Northern Europe “England”

Simulated data Use a set of simulations carried out for the 4 th Assessment report. (WCRP archive) Simulations forced with both Natural and Human drivers. –From 1890 (or earlier) to 2100 (A2). 22 –From 1890 (or earlier) to Simulations forced with natural only drivers –From 1890 to Control simulations (Constant forcing) 4500 years

Data processing Simulated monthly-mean data interpolated to observed grid Masked by observed data (only have simulated data where there are observations) Convert precipitation data to percentage anomalies relative to (if keep as total will be focused to regions with high precipitation) Temperature data as anomalies relative to Data averaged over regions to produce time series. Time-series averaged to produce warm (May-Oct) and cold (Nov-Apr) seasons.

Testing model variability

Detection

Attribution Different model simulations = different symbols. X means inconsistent Warm Cold

Summary Likely that European regional climate is changing due to human influences Warming throughout year Strongest precipitation signals in “cold” season –Drying in Med and moistening in other regions –“England” showing summer drying as well Combined analysis of Precip and Temperature better than each individually.