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