Extreme weather and climate in Europe

This report describes the current scientific knowledge of extreme weather and climate events in Europe for the following variables: temperature, precipitation, hail, and drought (with the following types of drought: meteorological, hydrological and soil moisture). The content summarises key literature drawn from peer reviewed journals and other sources (business and government reports), and builds upon the synthesised results presented in international assessments such as IPCC reports. It describes the recorded observations and modelled projections for extreme events including definitions, frequency, trends, spatial and temporal distribution. The report also presents an overview of the indices used to characterise extreme events as well as their main uses, before going on to describe the datasets where they are recorded, and provides information on the strengths and weaknesses of the indices and the datasets. Extra consideration is given to indices that are relevant to socio-economic impacts resulting from climate change and relevant statistical techniques for analysing extreme events. Observed changes in global climate and extreme events provide the context to the changes in extreme events observed in Europe, which are described for much of the 20th century. Modelled projections of extreme events are also given, under different emissions scenarios and time horizons, including results from regional models covering the European domain, such as EURO-CORDEX. The report is written for climate scientists, climate researchers and experts who use climate information in a professional role. There are four case studies (Appendix 2) which provide an anatomy of different recent European extreme weather/climate events including meteorological impacts and synoptic context. Observed global temperature trends show the number of warm extremes has increased and number of cool extremes has decreased over the last 100 years, and the length and frequency of summer heat waves has increased during the last century. In Europe these trends are most pronounced in the last 40 years although regional variations exist. For Europe, 2014 was the warmest year on record, although it had fewer hot days than recent years. Under future climate change with continued warming, the number of heat waves is projected to increase, along with their duration and intensity. Under all emissions scenarios, summers like the hot summer experienced in 2003 will become commonplace by the 2040s. The global trend in precipitation is generally for wetter conditions over the 20th century although changes are less temporally and spatially coherent than those observed for temperature. The general trend in precipitation for Europe in the 20th century is of increases over northern Europe and decreases over southern Europe. Extreme precipitation is becoming more intense and more frequent in Europe, especially in central and eastern Europe in winter, often resulting in greater and more frequent flooding. Since 1950 winter wet spells increased in duration in northern Europe and reduced in southern Europe, while summer wet spells became shorter in northern and eastern Europe. An increasing proportion of total rainfall is observed to fall on heavy rainfall days. Extreme precipitation (including short intense convective or longer duration frontal types) demonstrates complex variability and lacks a robust spatial pattern. Climate models project that events currently considered extreme are expected to occur more frequently in the future. For example a 1-in-20 year annual maximum daily precipitation amount is likely to become a 1-in-5 to 1-in-15 year event by the end of the 21st century in many parts of Europe. There are few ground based hail observation networks, so satellite measurements and weather models are used to identify hail forming conditions. In Europe most extreme hail events occur in the summer over Central Europe and the Alps where convective energy is greatest. Intense hail events are linked to increases in convective energy in the atmosphere observed over the last 30 years. Hailstorm projection studies, although limited to France, northern Italy and Germany, show increases in the convective conditions that lead to hail and some areas show a rise in damage days although this is not statistically significant. Recent severe droughts include Italy (1997-2002), the Baltic countries 2005-2009, the European heatwave of summer 2003, and the widespread European drought of 2011. The 1950s were prone to long, intense, Europe-wide meteorological and hydrological droughts. In northern and eastern Europe the highest drought frequency and severity was from the early 1950s to the mid-1970s. Southern and Western Europe (especially the Mediterranean) show the highest drought frequency and severity since 1990. There has been a small but continuous increase of the European areas prone to drought from the 1980s to the early 2010s. Regional climate models project a decrease in summer precipitation until 2100 of 17%. Dry periods are expected to occur 3 times more often at the end of this century and to last longer by 1 to 3 days compared to the period of 1971-2000. There is significant uncertainty associated with future projections of drought, with climate variability being the dominant source of uncertainty in observed and projected soil moisture drough

Inverse Modelling of National and EU Greenhouse Gas Emission Inventories. Report of the Workshop "Inverse Modelling for Potential Verification of National and EU Bottom-up GHG Inventories" under the mandate of the Monitoring Mechanism Committee WG-1, 23-2

Abstract not availableJRC.H-Institute for environment and sustainability (Ispra

Adapting to Europe's Changing Climate

Global climate change means temperatures are increasing, sea levels rising, glaciers and ice melting, precipitation is changing and the intensity and frequency of weather extremes are escalating.JRC.H.7-Land management and natural hazard

Combining EMI and GPR for non-invasive soil sensing at the Stonehenge World Heritage Site: the reconstruction of a WW1 practice trench

Increasingly, conventional soil sampling procedures face restrictions because of their destructive character. Hence there is a growing interest in non-invasive techniques, on which proximal soil sensors are based. There is great interest in applying proximal soil sensing to improve the characterization of the buried heritage embedded in the soil landscape at sites such as the Stonehenge World Heritage Site, UK. Because calibration and validation procedures based on invasive practices are unconventional, we turned to the investigation of a well-documented practice trench dug during the First World War (WW1) close to the prehistoric Stonehenge monument. A methodology was tested that would simultaneously invert frequency-domain ground-penetrating radar (GPR) and multi-receiver electromagnetic induction (EMI) data, with the aim of reconstructing the trench network. This trench network could not be distinguished on the EMI apparent electrical conductivity (sigma(a)) measurements, but appeared on the apparent magnetic susceptibility ((a)) data. The GPR measurements showed the trench infilling as strong reflections contrasting with the surrounding soil. However, converting the two-way travel times to absolute depths requires knowledge of the relative permittivity (epsilon(r)). Because of the preference for non-invasive observation in this protected landscape, we developed a procedure integrating the GPR measurements with (a) measurements obtained with EMI. A fitting procedure, assuming a constant susceptibility and permittivity of the sub-surface layers, allowed us to estimate both the susceptibility of the trench fill and the surrounding soil material, and the epsilon(r) value of the material above and within the trench. This provided absolute depth values for the GPR reflection data, improving the lateral and vertical reconstruction of the trench system. Moreover, these results allowed depth slices to be determined from EMIa data. So, integrating both GPR and EMI measurements enabled the detailed reconstruction of the buried trench network at Stonehenge, offering new perspectives on the investigation of features buried within the soil of protected sites