Severe wind gust thresholds for Meteoalarm derived from uniform return periods in ECA&D Natural Hazards and Earth System Sciences DOI 10.5194/nhess-12-1969-2012 25 June 2012 In this study we present an alternative wind gust warning guideline for Meteoalarm, the severe weather warning website for Europe. There are unrealistically large differences in levels and issuing frequencies of all warning levels currently in use between neighbouring Meteoalarm countries. This study provides a guide for the Meteoalarm community to review their wind gust warning thresholds. Read more
Introduction to the European Monitoring and Evaluation Programme (EMEP) and observed atmospheric composition change during 1972–2009 Atmospheric Chemistry and Physics DOI 10.5194/acp-12-5447-2012 22 June 2012 European scale harmonized monitoring of atmospheric composition was initiated in the early 1970s, and the activity has generated a comprehensive dataset which allows the evaluation of regional and spatial trends of air pollution during a period of nearly 40 yr. Read more
Impact of heat and drought stress on arable crop production in Belgium Natural Hazards and Earth System Sciences DOI 10.5194/nhess-12-1911-2012 18 June 2012 Modelling approaches are needed to accelerate understanding of adverse weather impacts on crop performances and yields. The aim was to elicit biometeorological conditions that affect Belgian arable crop yield, commensurate with the scale of climatic impacts. Read more
Towards a merged satellite and in situ fluorescence ocean chlorophyll product Biogeosciences DOI 10.5194/bg-9-2111-2012 12 June 2012 Understanding the ocean carbon cycle requires a precise assessment of phytoplankton biomass in the oceans. In terms of numbers of observations, satellite data represent the largest available data set. However, as they are limited to surface waters, they have to be merged with in situ observations. Read more
Solar irradiance reduction to counteract radiative forcing from a quadrupling of CO2: climate responses simulated by four earth system models Earth System Dynamics DOI 10.5194/esd-3-63-2012 6 June 2012 In this study we compare the response of four state-of-the-art Earth system models to climate engineering under scenario G1 of two model intercomparison projects: GeoMIP (Geoengineering Model Intercomparison Project) and IMPLICC (EU project “Implications and risks of engineering solar radiation to limit climate change”). Read more
Organic matter dynamics and stable isotope signature as tracers of the sources of suspended sediment Biogeosciences DOI 10.5194/bg-9-1985-2012 4 June 2012 Suspended sediment (SS) and organic matter in rivers can harm brown trout Salmo trutta by affecting the health and fitness of free swimming fish and by causing siltation of the riverbed. The temporal and spatial dynamics of sediment, carbon (C), and nitrogen (N) during the brown trout spawning season in a small river of the Swiss Plateau were assessed and C isotopes as well as the C/N atomic ratio were used to distinguish autochthonous and allochthonous sources of organic matter in SS loads. Read more
The spatial structure of European wind storms as characterized by bivariate extreme-value Copulas Natural Hazards and Earth System Sciences DOI 10.5194/nhess-12-1769-2012 29 May 2012 The winds associated with extra-tropical cyclones are amongst the costliest natural perils in Europe. Re/insurance companies typically have insured exposure at multiple locations and hence the losses they incur from any individual storm crucially depend on that storm’s spatial structure. Motivated by this, this study investigates the spatial structure of the most extreme windstorms in Europe. Read more
Drivers of flood risk change in residential areas Natural Hazards and Earth System Sciences DOI 10.5194/nhess-12-1641-2012 23 May 2012 The observed increase of direct flood damage over the last decades may be caused by changes in the meteorological drivers of floods, or by changing land-use patterns and socio-economic developments. It is still widely unknown to which extent these factors will contribute to future flood risk changes. Read more
Photo-lability of deep ocean dissolved black carbon Biogeosciences DOI 10.5194/bg-9-1661-2012 9 May 2012 Dissolved black carbon (DBC) is a significant component of the oceanic dissolved organic carbon (DOC) pool. In the current study, the photo-lability of DBC, DOC and coloured dissolved organic matter (CDOM; ultraviolet-visible absorbance) were determined over the course of a 28 day irradiation of North Atlantic Deep Water under a solar simulator. Read more
On the role of ozone in long-term trends in the upper atmosphere-ionosphere system Annales Geophysicae DOI 10.5194/angeo-30-811-2012 8 May 2012 Recently, Walsh and Oliver (2011) suggested that the long-term cooling of the upper thermosphere (above 200 km) may be due largely to the stratospheric ozone depletion. Here, we show that the role of ozone is very important in the mesosphere and lower thermosphere but not in the upper thermosphere. Read more