Towards observation-based gridded runoff estimates for Europe Hydrology and Earth System Sciences DOI 10.5194/hess-19-2859-2015 22 June 2015 Water storages and fluxes on land are key variables in the earth system. To provide context for local investigations and to understand phenomena that emerge at large spatial scales, information on continental freshwater dynamics is needed. This paper presents a methodology to estimate continental scale runoff on a 0.5° spatial grid, which combines the advantages of in-situ observations with the power of machine learning regression. The resulting runoff estimates compare well with observations. Read more
Dynamics of the Oso-Steelhead landslide from broadband seismic analysis Natural Hazards and Earth System Sciences DOI 10.5194/nhess-15-1265-2015 17 June 2015 We carry out a study of the seismic signals generated by the devastating Oso-Steelhead landslides. We invert the long-period seismic signals generated by the first main event and obtain estimates of its trajectory, kinematics and mass. No distinct long-period surface waves were recorded for the second failure, which prevents inversion for its source parameters. However, from the comparison of the energy of the short-period waves generated by both events, we can estimate the volume of the second. Read more
Technical Note: How accurate can stalagmite formation temperatures be determined using vapour bubble radius measurements in fluid inclusions? Climate of the Past DOI 10.5194/cp-11-905-2015 17 June 2015 Fluid inclusions inside stalagmites retain information on the cave temperature at the time they formed and thus can be used to reconstruct the continental climate of the past. A method for extracting this information based on a thermodynamic model and size measurements of femtosecond-laser-induced vapour bubbles is presented. Applying our method to stalagmites taken from the Milandre cave in the Swiss Jura Mountains demonstrate that palaeotemperatures can be determined with an accuracy of ±1°C. Read more
Brief Communication: Newly developing rift in Larsen C Ice Shelf presents significant risk to stability The Cryosphere DOI 10.5194/tc-9-1223-2015 15 June 2015 Within the last year, a large rift in the southern part of the Larsen C Ice Shelf, Antarctic Peninsula, propagated towards the inner part of the ice shelf. In this study we present the development of the rift as derived from remote sensing data and assess the impact of possible calving scenarios on the future stability of the Larsen C Ice Shelf, using a numerical model. We find that the calving front is likely to become unstable after the anticipated calving events. Read more
Large-basin hydrological response to climate model outputs: uncertainty caused by internal atmospheric variability Hydrology and Earth System Sciences DOI 10.5194/hess-19-2737-2015 15 June 2015 Our paper is one of very few studies where the influence of stochastic internal atmospheric variability (IAV) on the hydrological response is analyzed. On the basis of ensemble experiments with GCM and hydrological models, we found, e.g., that averaging over ensemble members filters the stochastic term related to IAV, and that a considerable portion of the simulated trend in annual Lena R. runoff can be explained by the externally forced signal (global SST and SIC changes in our experiments). Read more
A large-scale simulation model to assess karstic groundwater recharge over Europe and the Mediterranean Geoscientific Model Development DOI 10.5194/gmd-8-1729-2015 11 June 2015 We present a new approach to assess karstic groundwater recharge over Europe and the Mediterranean. Cluster analysis is used to subdivide all karst regions into four typical karst landscapes and to simulate karst recharge with a process-based karst model. We estimate its parameters by a combination of a priori information and observations of soil moisture and evapotranspiration. Independent observations of recharge that present large-scale models significantly under-estimate karstic recharge. Read more
Twelve thousand years of dust: the Holocene global dust cycle constrained by natural archives Climate of the Past DOI 10.5194/cp-11-869-2015 11 June 2015 We propose an innovative framework to organize paleodust records, formalized in a publicly accessible database, and discuss the emerging properties of the global dust cycle during the Holocene by integrating our analysis with simulations performed with the Community Earth System Model. We show how the size distribution of dust is intrinsically related to the dust mass accumulation rates and that only considering a consistent size range allows for a consistent analysis of the global dust cycle. Read more
A 50 % increase in the mass of terrestrial particles delivered by the Mackenzie River into the Beaufort Sea (Canadian Arctic Ocean) over the last 10 years Biogeosciences DOI 10.5194/bg-12-3551-2015 9 June 2015 Eleven years (2003-2013) of satellite data were processed to observe the variations in suspended particulate matter concentrations at the mouth of the Mackenzie River and estimate the fluxes exported into the Canadian Arctic Ocean. Results show that these concentrations at the river mouth, in the delta zone and in the river plume have increased by 46%, 71% and 33%, respectively, since 2003. This corresponds to a more than 50% increase in particulate export from the river into the Beaufort Sea. Read more
Emergence of multiple ocean ecosystem drivers in a large ensemble suite with an Earth system model Biogeosciences DOI 10.5194/bg-12-3301-2015 3 June 2015 A large initial-condition ensemble suite of simulations with an Earth system model is applied to evaluate emergence characteristics of four ocean ecosystem drivers under climate change. The drivers considered are warming, acidification, deoxygenation, and perturbations to biological productivity. The spatial and temporal hierarchies of the emergence of these drivers are considered, using concepts of both time of emergence and confidence intervals. Read more
Ideas and perspectives: on the emission of amines from terrestrial vegetation in the context of new atmospheric particle formation Biogeosciences DOI 10.5194/bg-12-3225-2015 3 June 2015 In this article we summarise recent science which shows how airborne amines, specifically methylamines (MAs), play a key role in new atmospheric particle formation (NPF) by stabilising small molecule clusters. Read more
Snowfall in the Himalayas: an uncertain future from a little-known past The Cryosphere DOI 10.5194/tc-9-1147-2015 2 June 2015 Snow and ice provide large amounts of meltwater to the Indus, Ganges and Brahmaputra rivers. In this study we show that climate change will reduce the amount of snow falling in the Himalayas, Hindu Kush and Karakoram substantially. The limited number of observations in remote upper-level terrain makes it difficult to get a complete overview of the situation today, but our results indicate that by 2071–2100 snowfall may be reduced by 30–70% with the strongest anthropogenic forcing scenario. Read more
Reliable, robust and realistic: the three R’s of next-generation land-surface modelling Atmospheric Chemistry and Physics DOI 10.5194/acp-15-5987-2015 29 May 2015 Land surface models (LSMs) describe how carbon and water fluxes react to environmental change. They are key component of climate models, yet they differ enormously. Many perform poorly, despite having many parameters. We outline a development strategy emphasizing robustness, reliability and realism, none of which is guaranteed by complexity alone. We propose multiple constraints, benchmarking and data assimilation, and representing unresolved processes stochastically, as tools in this endeavour. Read more
Modelling glacier change in the Everest region, Nepal Himalaya The Cryosphere DOI 10.5194/tc-9-1105-2015 27 May 2015 A glacier mass balance and redistribution model that integrates field observations and downscaled climate fields is developed to examine glacier sensitivity to future climate in the Everest region of Nepal. The modelled sensitivity of glaciers to future climate change is high, and glacier mass loss is sustained through the 21st century for both middle- and high-emission scenarios. Projected temperature increases will expose large glacier areas to melt and reduce snow accumulations. Read more
Local and regional scale measurements of CH4, δ13CH4, and C2H6 in the Uintah Basin using a mobile stable isotope analyzer Atmospheric Measurement Techniques DOI 10.5194/amtd-8-4859-2015 13 May 2015 We describe an innovative instrument based on cavity ring down spectroscopy that analyzes the stable isotopes of methane in the ambient atmosphere. This instrument was used to study atmospheric emissions from oil and gas extraction activities in the Uintah Basin in Utah. These measurements suggest that 86 ± 7% of the total emissions in the basin are from natural gas production. The easy field deployment of this instrument can enable similar regional attribution studies across the world. Read more
Oceanic and atmospheric forcing of Larsen C Ice-Shelf thinning The Cryosphere DOI 10.5194/tc-9-1005-2015 13 May 2015 Antarctic Peninsula ice shelves have collapsed in recent decades. The surface of Larsen C Ice Shelf is lowering, but the cause of this has not been understood. This study uses eight radar surveys to show that the lowering is caused by both ice loss and a loss of air from the ice shelf’s snowpack. At least two different processes are causing the lowering. The stability of Larsen C may be at risk from an ungrounding of Bawden Ice Rise or ice-front retreat past a ‘compressive arch’ in strain rates. Read more
The GAMDAM glacier inventory: a quality-controlled inventory of Asian glaciers The Cryosphere DOI 10.5194/tc-9-849-2015 6 May 2015 We present a new glacier inventory for high-mountain Asia named Glacier Area Mapping for Discharge from the Asian Mountains (GAMDAM). Glacier outlines were delineated manually using 356 Landsat ETM+ scenes in 226 path-row sets from the period 1999–2003, in conjunction with a digital elevation model and high-resolution Google EarthTM imagery. Our GAMDAM Glacier Inventory includes 87,084 glaciers covering a total area of 91,263 ± 13,689 km2 throughout high-mountain Asia. Read more
Open ocean dead zones in the tropical North Atlantic Ocean Biogeosciences DOI 10.5194/bg-12-2597-2015 30 April 2015 This study is the first report of the formation of dead zones in the open ocean. A combination of multiple ocean observing system elements (mooring, floats, satellites, ships) allowed us to reconstruct the generation of the dead zones and to connect the formation to enhanced respiration within mesoscale ocean eddies. The dead zones present specific threats to the ecosystem, such as the interruption of the diurnal migration of zooplankters. Read more
Storm type effects on super Clausius–Clapeyron scaling of intense rainstorm properties with air temperature Hydrology and Earth System Sciences DOI 10.5194/hess-19-1753-2015 16 April 2015 We present an empirical study of the rates of increase in precipitation intensity with air temperature using high-resolution 10 min precipitation records in Switzerland. We estimated the scaling rates for lightning (convective) and non-lightning event subsets and show that scaling rates are between 7 and 14%/C for convective rain and that mixing of storm types exaggerates the relations to air temperature. Doubled CC rates reported by other studies are an exception in our data set. Read more
Field survey report and satellite image interpretation of the 2013 Super Typhoon Haiyan in the Philippines Natural Hazards and Earth System Sciences DOI 10.5194/nhess-15-805-2015 10 April 2015 Super Typhoon Haiyan devastated the Eastern Visayas islands of the Philippines on 8 November 2013. The International Research Institute of Disaster Science (IRIDeS) at Tohoku University in Sendai, Japan, deployed several teams for damage recognition, relief support and collaboration with regard to this event. In this paper, we summarize the rapid damage assessment from satellite imagery conducted days after the event and report on the inundation measurements and damage surveyed in the field. Read more
On producing sea ice deformation data sets from SAR-derived sea ice motion The Cryosphere DOI 10.5194/tc-9-663-2015 9 April 2015 We present a new method to compute sea ice deformation fields from satellite-derived motion. The method particularly reduces the artificial noise that arises along discontinuities in the sea ice motion field. We estimate that this artificial noise may cause an overestimation of about 60% of sea ice opening and closing. The constant overestimation of the opening and closing could have led in previous studies to a large overestimation of freezing in leads, salt rejection and sea ice ridging. Read more