The importance of terrestrial weathering changes in multimillennial recovery of the global carbon cycle: a two-dimensional perspective Earth System Dynamics DOI 10.5194/esd-8-455-2017 30 June 2017 In this paper we describe the development and application of a new spatially explicit weathering scheme within the University of Victoria Earth System Climate Model (UVic ESCM). We integrated a dataset of modern-day lithology with a number of previously devised parameterizations for weathering dependency on temperature, primary productivity, and runoff. We tested the model with simulations of future carbon cycle perturbations and confirmed the importance of silicate weathering in the long term. Read more
Opposite long-term trends in aerosols between low and high altitudes: a testimony to the aerosol–PBL feedback Atmospheric Chemistry and Physics DOI 10.5194/acp-17-7997-2017 30 June 2017 Opposite trends in aerosol loading between the lower and upper planetary boundary layer are found on a wide range of timescales and from different types of data acquired by various platforms in China. The reversal trend is consistent with the strong vertical gradients in the aerosol-induced atmospheric heating rate that unevenly modifies the atmospheric temperature profile and alters the stability differently. The findings have multiple implications in understanding and combating air pollution. Read more
STRAPS v1.0: evaluating a methodology for predicting electron impact ionisation mass spectra for the aerosol mass spectrometer Geoscientific Model Development DOI 10.5194/gmd-10-2365-2017 27 June 2017 Our ability to model the chemical and thermodynamic processes that lead to secondary organic aerosol (SOA) formation is thought to be hampered by the complexity of the system. In this proof of concept study, the ability to train supervised methods to predict electron impact ionisation (EI) mass spectra for the AMS is evaluated to facilitate improved model evaluation. The study demonstrates the use of a methodology that would be improved with more training data and data from simple mixed systems. Read more
Statistical characteristics of convective wind gusts in Germany Natural Hazards and Earth System Sciences DOI 10.5194/nhess-17-957-2017 23 June 2017 Due to the small-scale and non-stationary nature of the convective wind gusts usually associated with thunderstorms, there is a considerable lack of knowledge regarding their characteristics and statistics. Thus, we investigated the temporal and spatial distribution, intensity, and return values of those wind events in Germany. The study constitutes a fundamental addition to an improved understanding of convective wind gusts and serves as basis for further risk assessments. Read more
The European 2015 drought from a hydrological perspective Hydrology and Earth System Sciences DOI 10.5194/hess-21-3001-2017 22 June 2017 In 2015 large parts of Europe were affected by a drought. In terms of low flow magnitude, a region around the Czech Republic was most affected, with return periods > 100 yr. In terms of deficit volumes, the drought was particularly severe around S. Germany where the event lasted notably long. Meteorological and hydrological events developed differently in space and time. For an assessment of drought impacts on water resources, hydrological data are required in addition to meteorological indices. Read more
Hypsometric amplification and routing moderation of Greenland ice sheet meltwater release The Cryosphere DOI 10.5194/tc-11-1371-2017 9 June 2017 The Greenland ice sheet melts faster in a warmer climate. The ice sheet is flatter at high elevation, therefore atmospheric warming increases the melt area exponentially. For current climate conditions, we find that the ice sheet shape amplifies the total meltwater generation by roughly 60 %. Meltwater is not stored underneath the ice sheet, as previously found, but it does take multiple days for it to pass through the seasonally developing subglacial drainage channels, moderating discharge. Read more
Debris-flow modeling at Meretschibach and Bondasca catchments, Switzerland: sensitivity testing of field-data-based entrainment model Natural Hazards and Earth System Sciences DOI 10.5194/nhess-17-801-2017 1 June 2017 This study describes a sensitivity analysis of the RAMMS debris-flow entrainment model, which is intended to help solve problems related to predicting the runout of debris flows. The results indicate that the entrainment model predicts plausible erosion volumes in comparison with field data. These eroded volumes are sensitive to the initial landslide volume, suggesting that this tool may be useful for both reconstruction of historical events and modeling of debris flow scenarios. Read more
Non-linear effects of pore pressure increase on seismic event generation in a multi-degree-of-freedom rate-and-state model of tectonic fault sliding Nonlinear Processes in Geophysics DOI 10.5194/npg-24-215-2017 22 May 2017 The influence of fluid injection on tectonic fault sliding and generation of seismic events was studied in the paper by a multi-degree-of-freedom rate-and-state friction model with a two-parametric friction law. The considered system could exhibit different types of motion. The main seismic activity could appear directly after the start of fluid injection or in the post-injection phase (after some days or months). Such an influence of injection on seismicity is observed in the real cases. Read more
The polar amplification asymmetry: role of Antarctic surface height Earth System Dynamics DOI 10.5194/esd-8-323-2017 18 May 2017 The Arctic has been warming much faster than the rest of the globe, including Antarctica. Here it was shown that one of the important mechanisms that sets Antarctica apart from the Arctic is heat transport from lower latitudes, and it was argued that a decrease in land height due to Antarctic melting would be favorable for increased atmospheric heat transport from midlatitudes. Other factors related to the larger Antarctic land height were also investigated. Read more
Ozone and haze pollution weakens net primary productivity in China Atmospheric Chemistry and Physics DOI 10.5194/acp-17-6073-2017 16 May 2017 While it is widely recognized that air pollutants adversely affect human health and climate change, their impacts on the regional carbon balance are less well understood. We apply an Earth system model to quantify the combined effects of ozone and aerosol particles on net primary production in China. Ozone vegetation damage dominates over the aerosol effects, leading to a substantial net suppression of land carbon uptake in the present and future worlds. Read more