Ideas and perspectives: Holocene thermokarst sediments of the Yedoma permafrost region do not increase the northern peatland carbon pool Biogeosciences DOI 10.5194/bg-13-2003-2016 6 April 2016 We investigate the properties of soils and sediments in a particular and ancient Siberian permafrost landscape. We critically examine statements from a recent study that specific permafrost landforms affected by thawed permafrost (alases) in this region contain very large quantities of peat that previous studies had failed to include because of data set biases. We conclude that there is no evidence to suggest biases in existing data sets or that alas deposits increase the northern peatland pool. Read more
Solar modulation of flood frequency in central Europe during spring and summer on interannual to multi-centennial timescales Climate of the Past DOI 10.5194/cp-12-799-2016 1 April 2016 Integrating discharge data of the River Ammer back to 1926 and a 5500-year flood layer record from an annually laminated sediment core of the downstream Ammersee allowed investigating changes in the frequency of major floods in Central Europe on interannual to multi-centennial timescales. Significant correlations between flood frequency variations in both archives and changes in the activity of the Sun suggest a solar influence on the frequency of these hydrometeorological extremes. Read more
Stratospheric ozone changes under solar geoengineering: implications for UV exposure and air quality Atmospheric Chemistry and Physics DOI 10.5194/acp-16-4191-2016 31 March 2016 Various forms of solar radiation management (SRM) have been proposed to counteract man-made climate change. However, all these countermeasures could have unintended side-effects. We add a novel perspective to this discussion by showing how atmospheric ozone changes under solar geoengineering could affect UV exposure and air pollution. This would have implications for human health and ecology. Atmospheric composition changes are therefore important to consider in the evaluation of any SRM scheme. Read more
Ice melt, sea level rise and superstorms: evidence from paleoclimate data, climate modeling, and modern observations that 2 ∘C global warming could be dangerous Atmospheric Chemistry and Physics DOI 10.5194/acp-16-3761-2016 22 March 2016 We use climate simulations, paleoclimate data and modern observations to infer that continued high fossil fuel emissions will yield cooling of Southern Ocean and North Atlantic surfaces, slowdown and shutdown of SMOC & AMOC, increasingly powerful storms and nonlinear sea level rise reaching several meters in 50-150 years, effects missed in IPCC reports because of omission of ice sheet melt and an insensitivity of most climate models, likely due to excessive ocean mixing. Read more
Coevolution of volcanic catchments in Japan Hydrology and Earth System Sciences DOI 10.5194/hess-20-1133-2016 16 March 2016 We derived indices of landscape properties as well as hydrological response and examined their relation with catchment age and climate. We found significant correlation between drainage density and baseflow index with age, but not with climate. We compared our data with data from volcanic catchments in Oregon and could confirm that baseflow index decreases with time, but also discovered that drainage density seems to stabilize after 2M years, after an initial increase due to landscape incision. Read more
Maximum wind radius estimated by the 50 kt radius: improvement of storm surge forecasting over the western North Pacific Natural Hazards and Earth System Sciences DOI 10.5194/nhess-16-705-2016 11 March 2016 We proposed an Rmax estimation method based on the radius of the 50 knot wind (R50). The data obtained during the passage of strong typhoons by a meteorological station network in the Japanese archipelago enabled us to derive the following simple formula, Rmax = 0.23 R50. The proposed method is expected to increase the reliability of storm surge prediction and contribute to disaster risk management, particularly in the western North Pacific. Read more
Imprints of climate forcings in global gridded temperature data Earth System Dynamics DOI 10.5194/esd-7-231-2016 11 March 2016 Using regression analysis, near-surface temperatures from several gridded data sets were investigated for the presence of components attributable to external climate forcings and to major internal climate variability modes, over the 1901-2010 period. The spatial patterns of local temperature response and their combination in globally averaged temperature were shown and discussed, with special focus on highlighting the inter-dataset contrasts. Read more
Phase, composition, and growth mechanism for secondary organic aerosol from the ozonolysis of α-cedrene Atmospheric Chemistry and Physics DOI 10.5194/acp-16-3245-2016 11 March 2016 A significant fraction of airborne particles, which have significant impacts on human health, visibility, and climate, are formed from the oxidation of gaseous precursors to generate low-volatility products. We show here that a sesquiterpene, α-cedrene, efficiently forms high-viscosity semisolid particles with complex composition via mechanisms that involve the highly reactive Criegee intermediate and that high molecular weight products play an important role in new particle formation. Read more
Delaying future sea-level rise by storing water in Antarctica Earth System Dynamics DOI 10.5194/esd-7-203-2016 10 March 2016 Sea level will continue to rise for centuries. We investigate the option of delaying sea-level rise by pumping ocean water onto Antarctica. Due to wave propagation ice is discharged much faster back into the ocean than expected from pure advection. A millennium-scale storage of >80% of the additional ice requires a distance of >700km from the coastline. The pumping energy required to elevate ocean water to mitigate a sea-level rise of 3mm/yr exceeds 7% of current global primary energy supply. Read more
Upwellings mitigated Plio-Pleistocene heat stress for reef corals on the Florida platform (USA) Biogeosciences DOI 10.5194/bg-13-1469-2016 10 March 2016 We present stable isotope proxy data and calcification records from fossil reef corals. The corals investigated derive from the Florida carbonate platform and are of middle Pliocene to early Pleistocene age. From the data we infer an environment subject to intermittent upwelling on annual to decadal timescales. Calcification rates were enhanced during periods of upwelling. This is likely an effect of dampened SSTs during the upwelling. Read more
Recent summer sea ice thickness surveys in Fram Strait and associated ice volume fluxes The Cryosphere DOI 10.5194/tc-10-523-2016 8 March 2016 We present an extensive data set of ground-based and airborne electromagnetic ice thickness measurements covering Fram Strait in summer between 2001 and 2012. An investigation of back trajectories of surveyed sea ice using satellite-based sea ice motion data allows us to examine the connection between thickness variability, ice age and source area. In addition, we determine across and along strait gradients in ice thickness and associated volume fluxes. Read more
The airborne mass spectrometer AIMS – Part 1: AIMS-H2O for UTLS water vapor measurements Atmospheric Measurement Techniques DOI 10.5194/amt-9-939-2016 7 March 2016 We present the development of a new airborne mass spectrometer AIMS-H2O for the fast and accurate measurement of water vapor in the upper troposphere and lower stratosphere. The high accuracy needed for e.g. quantification of atmospheric water vapor transport processes or cloud formation is achieved by an in-flight calibration of the instrument. AIMS-H2O is deployed on the DLR research aircraft HALO and Falcon where it covers a range of water vapor mixing ratios from 1 to 500 ppmv. Read more
Multi-instrument gravity-wave measurements over Tierra del Fuego and the Drake Passage – Part 1: Potential energies and vertical wavelengths from AIRS, COSMIC, HIRDLS, MLS-Aura, SAAMER, SABER and radiosondes Atmospheric Measurement Techniques DOI 10.5194/amt-9-877-2016 4 March 2016 Seven gravity-wave-resolving instruments (satellites, radiosondes and a meteor radar) are used to compare gravity-wave energy and vertical wavelength over the Southern Andes hotspot. Several conclusions are drawn, including that limb sounders and the radar show strong positive correlations. Radiosondes and AIRS weakly anticorrelate with other instruments and we see strong correlations with local stratospheric winds. Short-timescale variability is larger than the seasonal cycle. Read more
Bulk meltwater flow and liquid water content of snowpacks mapped using the electrical self-potential (SP) method The Cryosphere DOI 10.5194/tc-10-433-2016 29 February 2016 We show that strong electrical self-potential fields are generated in melting in in situ snowpacks at Rhone Glacier and Jungfraujoch Glacier, Switzerland. We conclude that the electrical self-potential method is a promising snow and firn hydrology sensor, owing to its suitability for sensing lateral and vertical liquid water flows directly and minimally invasively, complementing established observational programs and monitoring autonomously at a low cost. Read more
World’s soils are under threat SOIL DOI 10.5194/soil-2-79-2016 29 February 2016 The Intergovernmental Technical Panel on Soils has completed the first State of the World’s Soil Resources Report. The gravest threats were identified for all the regions of the world. This assessment forms a basis for future soil monitoring. The quality of soil information available for policy formulation must be improved. Read more
Proof of concept: temperature-sensing waders for environmental sciences Geoscientific Instrumentation, Methods and Data Systems DOI 10.5194/gi-5-45-2016 29 February 2016 Temperature-sensor-incorporated waders worn by the public can give scientists an additional source of information on stream water-groundwater interaction. A pair of waders was equipped with a thermistor and calibrated in the lab. Field tests in a deep polder ditch with a known localized groundwater contribution showed that the waders are capable of identifying the boil location. This can be used to decide where the most interesting places are to do more detailed and more expensive research. Read more
All-clear for gourmets: truffles not radioactive Biogeosciences DOI 10.5194/bg-13-1145-2016 25 February 2016 Although ranging among the most expensive gourmet foods, it remains unclear whether truffles accumulate radioactivity at a harmful level comparable to other fungi. Insignificant radiocaesium concentrations in specimens from Switzerland, Germany, France, Italy, and Hungary provide an all-clear for truffle hunters and cultivators in Europe as well as dealers and customers from around the world. Read more
Apparent increase in coccolithophore abundance in the subtropical North Atlantic from 1990 to 2014 Biogeosciences DOI 10.5194/bg-13-1163-2016 25 February 2016 In this study, we combine phytoplankton pigment data with particulate inorganic carbon and chlorophyll measurements from the satellite record to assess recent trends in phytoplankton dynamics in the North Atlantic subtropical gyre, with a focus on coccolithophores. We show that coccolithophores in the North Atlantic have been increasing in abundance. Correlations suggest that they are responding positively to increasing inorganic carbon from anthropogenic inputs in the upper mixed layer. Read more
Atmospheric significance of aeolian salts in the sandy deserts of northwestern China Solid Earth DOI 10.5194/se-7-191-2016 4 February 2016 Salt archives in sediments are critical to understanding a number of geochemical processes in the earth surface conditions. This study presents a physical and geochemical survey into aeolian salts in the Chinese deserts to explore their possible climatic implications. The results suggest the aeolian salts are atmospheric origin without local geological limits. It is a latent indicator in onefold depositional environment but not so in diverse conditions. Palaeoenvironmental use should be careful. Read more
Runoff- and erosion-driven transport of cattle slurry: linking molecular tracers to hydrological processes Biogeosciences DOI 10.5194/bg-13-551-2016 1 February 2016 Our interdisciplinary research brings together methodologies from hydrology, soil science and biogeochemistry to address key questions about the transport of cattle slurry in the environment. The paper provides a novel approach to trace dissolved and particulate components of cattle slurry through an experimental hillslope system. This work provides one of the first examples of using biomarkers to assess the effects of slope gradient and rainfall intensity on the movement of slurry derived-OM. Read more