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
Estimating the climate significance of halogen-driven ozone loss in the tropical marine troposphere Atmospheric Chemistry and Physics DOI 10.5194/acp-12-3939-2012 4 May 2012 We find that the implementation of oceanic halogen sources and chemistry in climate models is an important component of the natural background ozone budget and we suggest that it needs to be considered when estimating both preindustrial ozone baseline levels and long term changes in tropospheric ozone. Read more
The regulation of the air: a hypothesis Solid Earth DOI 10.5194/se-3-87-2012 12 March 2012 We propose the hypothesis that natural selection, acting on the specificity or preference for CO2 over O2 of the enzyme rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase), has controlled the CO2:O2 ratio of the atmosphere since the evolution of photosynthesis and has also sustained the Earth’s greenhouse-set surface temperature. Read more
Global characteristics of the lunar tidal modulation of the equatorial electrojet derived from CHAMP observations Annales Geophysicae DOI 10.5194/angeo-30-527-2012 8 March 2012 It has been known since many decades that lunar tide has an influence on the strength of the equatorial electrojet (EEJ). There has, however, never been a comprehensive study of the tidal effect on a global scale. Based on the continuous magnetic field measurements by the CHAMP satellite over 10 years it is possible to investigate the various aspects of lunar effects on the EEJ. Read more
Evidence of a possible turning point in solar UV-B over Canada, Europe and Japan Atmospheric Chemistry and Physics DOI 10.5194/acp-12-2469-2012 5 March 2012 This study examines the long-term variability of UV solar irradiances at 305 nm and 325 nm over selected sites in Canada, Europe and Japan. Site selection was restricted to the availability of the most complete UV spectroradiometric datasets during the period 1990–2011. The analysis includes the long-term variability of total ozone, aerosol optical depth and cloud fraction at the sites studied. Read more
A tsunami wave recorded near a glacier front Natural Hazards and Earth System Sciences DOI 10.5194/nhess-12-415-2012 27 February 2012 We observed a tsunami wave near the glacier front in the Temple Fjord (Spitsbergen). Two temperature and pressure recorders were deployed on a wire from the ice approximately 300 m from the glacier front. The measurements allowed us to estimate the wave number of these waves and the Young’s modulus of the ice. Read more
