Estimating Greenland tidewater glacier retreat driven by submarine melting The Cryosphere DOI 10.5194/tc-13-2489-2019 26 September 2019 The ocean’s influence on the retreat of Greenland’s tidewater glaciers is a key factor determining future sea level. By considering observations of ~200 glaciers from 1960, we find a significant relationship between retreat and melting in the ocean. Projected forwards, this relationship estimates the future evolution of Greenland’s tidewater glaciers and provides a practical and empirically validated way of representing ice–ocean interaction in large-scale models used to estimate sea level rise. Read more
Global-scale human pressure evolution imprints on sustainability of river systems Hydrology and Earth System Sciences DOI 10.5194/hess-23-3933-2019 25 September 2019 A simple and effective index for the quantitative estimation of the evolution of human pressure on rivers at global scale is proposed. This index, based on nightlights and river discharge data, shows a significant increase from 1992 to 2013 worldwide. The most notable changes are found in river basins across Africa and Asia, where human pressure on rivers is growing markedly. This index identifies priority areas that can be targeted for the implementation of mitigation strategies and plans. Read more
Hybrid-Vlasov modelling of nightside auroral proton precipitation during southward interplanetary magnetic field conditions Annales Geophysicae DOI 10.5194/angeo-37-791-2019 10 September 2019 When the terrestrial magnetic field is disturbed, particles from the near-Earth space can precipitate into the upper atmosphere. This work presents, for the first time, numerical simulations of proton precipitation in the energy range associated with the production of aurora (∼1–30 keV) using a global kinetic model of the near-Earth space: Vlasiator. We find that nightside proton precipitation can be regulated by the transition region between stretched and dipolar geomagnetic field lines. Read more
How can geologic decision-making under uncertainty be improved? Solid Earth DOI 10.5194/se-10-1469-2019 3 September 2019 In this paper, we outline the key insights from decision-making research about how, when faced with uncertainty, humans constrain decisions through the use of heuristics (rules of thumb), making them vulnerable to systematic and suboptimal decision biases. We also review existing strategies to debias decision-making that have applicability in the geosciences, giving special attention to strategies that make use of information technology and artificial intelligence. Read more
Improved methodologies for Earth system modelling of atmospheric soluble iron and observation comparisons using the Mechanism of Intermediate complexity for Modelling Iron (MIMI v1.0) Geoscientific Model Development DOI 10.5194/gmd-12-3835-2019 2 September 2019 MIMI v1.0 was designed for use within Earth system models to simulate the 3-D emission, atmospheric processing, and deposition of iron and its soluble fraction. Understanding the iron cycle is important due to its role as an essential micronutrient for ocean phytoplankton; its supply limits primary productivity in many of the world’s oceans. Human activity has perturbed the iron cycle, and MIMI is capable of diagnosing many of these impacts; hence, it is important for future climate studies. Read more
CO2 effects on diatoms: a synthesis of more than a decade of ocean acidification experiments with natural communities Ocean Science DOI 10.5194/os-15-1159-2019 28 August 2019 Diatoms are a group of phytoplankton species responsible for ~ 25% of primary production on Earth. Ocean acidification (OA) could influence diatoms but the key question is if they become more or less important within marine food webs. We synthesize OA experiments with natural communities and found that diatoms are more likely to be positively than negatively affected by high CO2 and larger species may profit in particular. This has important implications for ecosystem services diatoms provide. Read more
Assessing the formation and evolution mechanisms of severe haze pollution in the Beijing–Tianjin–Hebei region using process analysis Atmospheric Chemistry and Physics DOI 10.5194/acp-19-10845-2019 28 August 2019 The formation mechanism of a severe haze episode that occurred over North China in December 2015, the aerosol radiative impacts on the haze event and the influence mechanism were examined. The PM2.5 increase during the aerosol accumulation stage was mainly attributed to strong production by the aerosol chemistry process and weak removal by advection and vertical mixing. Restrained vertical mixing was the main reason for near-surface PM2.5 increase when aerosol radiative feedback was considered. Read more
A global delta dataset and the environmental variables that predict delta formation on marine coastlines Earth Surface Dynamics DOI 10.5194/esurf-7-773-2019 26 August 2019 River deltas are valuable resources that support biodiversity and human habitation. Despite this we do not have a global census of deltas nor do we know the conditions that promote their formation. We surveyed 5399 river mouths greater than 50 m wide and found that 2174 (40%) create a delta. The conditions that lead to delta formation are high sediment input and low wave and tide conditions. These results can be used to understand how deltas will adapt to environmental changes. Read more
Summary and synthesis of Changing Cold Regions Network (CCRN) research in the interior of western Canada – Part 1: Projected climate and meteorology Hydrology and Earth System Sciences DOI 10.5194/hess-23-3437-2019 23 August 2019 This article examines future atmospheric-related phenomena across the interior of western Canada associated with abusiness-as-usualclimate scenario. Changes in large-scale atmospheric circulation and extent of warming vary with season, and these generally lead to increases, especially after mid-century, in factors associated with winter snowstorms, freezing rain, drought, forest fires, as well as atmospheric forcing of spring floods, although not necessarily summer convection. Read more
A low-cost device for measuring local magnetic anomalies in volcanic terrain Geoscientific Instrumentation, Methods and Data Systems DOI 10.5194/gi-8-217-2019 22 August 2019 Our knowledge of the Earth’s magnetic field arises from magnetic signals stored in lavas. In rugged volcanic terrain, however, the magnetization of the underlying flows may influence the magnetic field as recorded by newly formed flows on top. To measure these local magnetic anomalies, we developed a low-cost field magnetometer with superior accuracy and user-friendliness. The first measurements on Mt. Etna show local magnetic variations that are much larger than expected. Read more
Fault-controlled dolomitization in the Montagna dei Fiori Anticline (Central Apennines, Italy): record of a dominantly pre-orogenic fluid migration Solid Earth DOI 10.5194/se-10-1355-2019 20 August 2019 The dolomitized intervals of the Lower Jurassic deposits exposed in the Montagna dei Fiori Anticline (Central Apennines, Italy) have been investigated. Accordingly, two fault-related dolomitization events were recognised and interpreted as having occurred before and during the Apenninic orogeny. The analyses suggest significant involvement of evaporitic fluids in both events, most likely derived from the underlying Upper Triassic Burano Formation in the detachment level. Read more
Load-resistance analysis: an alternative approach to tsunami damage assessment applied to the 2011 Great East Japan tsunami Natural Hazards and Earth System Sciences DOI 10.5194/nhess-19-1807-2019 20 August 2019 It is known that fragility functions reflect localities (building design standards and topography) and flow velocity is more important, as damage might occur before flow depth reaches its maximum value. This research demonstrates that it is possible to accurately predict building damage by considering related forces with high accuracy, including resistant force, based on building design standards. This method will be useful for damage assessment in areas that have no experience of tsunamis. Read more
Seismic risk: the biases of earthquake media coverage Geoscience Communication DOI 10.5194/gc-2-125-2019 15 August 2019 Exploring a corpus of 320 888 news articles published by 32 worldwide newspapers in 2015, this paper shows the following: news covers a very small proportion of the total number of earthquakes occurring in a year; the duration of coverage is very short, which does not allow for proper coverage of long-term issues; and there is a typical framing of the news about earthquakes that introduces major biases in representation, impeding proper appropriation of the seismic risk by the public. Read more
Unravelling the spatial diversity of Indian precipitation teleconnections via a non-linear multi-scale approach Nonlinear Processes in Geophysics DOI 10.5194/npg-26-251-2019 15 August 2019 We examined the spatial diversity of Indian rainfall teleconnection at different timescales, first by identifying homogeneous communities and later by computing non-linear linkages between the identified communities (spatial regions) and dominant climatic patterns, represented by climatic indices such as El Nino–Southern Oscillation, Indian Ocean Dipole, North Atlantic Oscillation, Pacific Decadal Oscillation and Atlantic Multi-Decadal Oscillation. Read more
Modelling ice sheet evolution and atmospheric CO2 during the Late Pliocene Climate of the Past DOI 10.5194/cp-15-1603-2019 15 August 2019 The Late Pliocene, 3.65–2.75 million years ago, is the most recent period in Earth’s history that was warmer than the present. This makes it interesting for climatological research, because it provides a possible analogue for the near future. We used a coupled ice-sheet–climate model to simulate the behaviour of these systems during this period. We show that the warmest moment saw a sea-level rise of 8–14 m, with a CO2 concentration of 320–400 ppmv. Read more
Multiresolution wavelet analysis applied to GRACE range-rate residuals Geoscientific Instrumentation, Methods and Data Systems DOI 10.5194/gi-8-197-2019 15 August 2019 In this paper, we present an approach to represent underlying errors in measurements and physical models in the temporal gravity field determination using GRACE observations. This study provides an opportunity to improve the error model and the accuracy of the GRACE parameter estimation, as well as its successor GRACE Follow-On. Read more
Ideas and perspectives: is shale gas a major driver of recent increase in global atmospheric methane? Biogeosciences DOI 10.5194/bg-16-3033-2019 14 August 2019 Atmospheric methane has risen rapidly since 2008 and has become more depleted in 13C, in contrast to the trend towards more 13C enrichment in the late 20th century. Many have used this isotopic evidence to infer an increased biogenic source. Here I analyze the 13C trend with the consideration that methane from shale gas is somewhat depleted in 13C compared to other fossil fuels. I conclude that shale gas may be responsible for a third of the global increase from all sources. Read more
High-resolution underwater laser spectrometer sensing provides new insights into methane distribution at an Arctic seepage site Ocean Science DOI 10.5194/os-15-1055-2019 13 August 2019 Methane seepage from the seafloor west of Svalbard was investigated with a fast-response membrane inlet laser spectrometer. The acquired data were in good agreement with traditional sparse discrete water sampling, subsequent gas chromatography, and with a new 2-D model based on echo-sounder data. However, the acquired high-resolution data revealed unprecedented details of the methane distribution, which highlights the need for high-resolution measurements for future climate studies. Read more
Taking a Breath of the Wild: are geoscientists more effective than non-geoscientists in determining whether video game world landscapes are realistic? Geoscience Communication DOI 10.5194/gc-2-117-2019 13 August 2019 Game worlds in modern computer games, while they include very Earth-like landscapes, are ultimately fake. Since games can be used for learning, we wondered if people pick up wrong information from games. Using a survey we tested if people with a background in geoscience are better than people without such a background at distinguishing if game landscapes are realistic. We found that geoscientists are significantly better at this, but the difference is small and overall everyone is good at it. Read more
Spatial pattern of accumulation at Taylor Dome during Marine Isotope Stage 4: stratigraphic constraints from Taylor Glacier Climate of the Past DOI 10.5194/cp-15-1537-2019 8 August 2019 An ice core from Taylor Glacier, Antarctica, spans a period ~ 70 000 years ago when Earth entered the last ice age. Chemical analyses of the ice and air bubbles allow for an independent determination of the ages of the ice and gas bubbles. The difference between the age of the ice and the bubbles at any given depth, called ∆age, is unusually high in the Taylor Glacier core compared to the Taylor Dome ice core situated to the south. This implies a dramatic accumulation gradient between the sites. Read more