Brief communication: Updated GAMDAM glacier inventory over high-mountain Asia The Cryosphere DOI 10.5194/tc-13-2043-2019 19 July 2019 The Glacier Area Mapping for Discharge from the Asian Mountains (GAMDAM) glacier inventory was updated to revise the underestimated glacier area in the first version. The total number and area of glaciers are 134 770 and 100 693 ± 11 790 km2 from 453 Landsat images, which were carefully selected for the period from 1990 to 2010, to avoid mountain shadow, cloud cover, and seasonal snow cover. Read more
Quantification of water vapour transport from the Asian monsoon to the stratosphere Atmospheric Chemistry and Physics DOI 10.5194/acp-19-8947-2019 12 July 2019 We investigate the transport pathways of water vapour from the upper troposphere in the Asian monsoon region to the stratosphere. In the employed chemistry-transport model we use a tagging method, such that the impact of different source regions on the stratospheric water vapour budget can be quantified. A key finding is that the Asian monsoon (compared to other source regions) is very efficient in transporting air masses and water vapour to the tropical and extratropical stratosphere. Read more
Evaluating post-glacial bedrock erosion and surface exposure duration by coupling in situ optically stimulated luminescence and 10Be dating Earth Surface Dynamics DOI 10.5194/esurf-7-633-2019 11 July 2019 Assessing the impact of glaciation at the Earth’s surface requires simultaneous quantification of the impact of climate variability on past glacier fluctuations and on bedrock erosion. Here we present a new approach for evaluating post-glacial bedrock surface erosion in mountainous environments by combining two different surface exposure dating methods. This approach can be used to estimate how bedrock erosion rates vary spatially and temporally since glacier retreat in an alpine environment. Read more
Dissolved organic matter at the fluvial–marine transition in the Laptev Sea using in situ data and ocean colour remote sensing Biogeosciences DOI 10.5194/bg-16-2693-2019 11 July 2019 In this article, we present the variability and characteristics of dissolved organic matter at the fluvial–marine transition in the Laptev Sea from a unique dataset collected during 11 Arctic expeditions. We develop a new relationship between dissolved organic carbon (DOC) and coloured dissolved organic matter absorption, which is used to estimate surface water DOC concentration from space. We believe that our findings help current efforts to monitor ongoing changes in the Arctic carbon cycle. Read more
Atmospheric measurements of the terrestrial O2:CO2 exchange ratio of a midlatitude forest Atmospheric Chemistry and Physics DOI 10.5194/acp-19-8687-2019 10 July 2019 Predictions of global warming require predictions of how much CO2 will be taken up by the oceans, how much by land plants, and how much will stay in the atmosphere. Measurements of atmospheric oxygen (O2) help with these predictions if we also know the ratio of O2 release to CO2 uptake in land plants. We have measured this ratio in a midlatitude forest and find a lower value than the one in wide use. If truly applicable, our results call for a modest adjustment in the global carbon budget. Read more
Evaluation of global simulations of aerosol particle and cloud condensation nuclei number, with implications for cloud droplet formation Atmospheric Chemistry and Physics DOI 10.5194/acp-19-8591-2019 8 July 2019 Effects of aerosols on clouds are important for climate studies but are among the largest uncertainties in climate projections. This study evaluates the skill of global models to simulate aerosol, cloud condensation nuclei (CCN) and cloud droplet number concentrations (CDNCs). Model results show reduced spread in CDNC compared to CCN due to the negative correlation between the sensitivities of CDNC to aerosol number concentration (air pollution) and updraft velocity (atmospheric dynamics). Read more
Flood risk in a range of spatial perspectives – from global to local scales Natural Hazards and Earth System Sciences DOI 10.5194/nhess-19-1319-2019 5 July 2019 Considering flood risk composed of hazard, exposure, and vulnerability from global to local scales, this paper reviews and presents increasing observed flood losses and projections of flood hazard and losses. We acknowledge existence of multiple driving factors and of considerable uncertainty, in particular with regards to projections for the future. Finally, this paper analyses options for flood risk reduction from a global framework to regional and local scales. Read more
Description of a formaldehyde retrieval algorithm for the Geostationary Environment Monitoring Spectrometer (GEMS) Atmospheric Measurement Techniques DOI 10.5194/amt-12-3551-2019 4 July 2019 The Geostationary Environment Monitoring Spectrometer (GEMS) will be launched by South Korea in 2019, and it will measure radiances ranging from 300 to 500 nm every hour with a fine spatial resolution of 7 km x 8 km over Seoul in South Korea to monitor column concentrations of air pollutants including O3, NO2, SO2, and HCHO, as well as aerosol optical properties. This paper describes a GEMS formaldehyde retrieval algorithm including a number of sensitivity tests for algorithm evaluation. Read more
Converting snow depth to snow water equivalent using climatological variables The Cryosphere DOI 10.5194/tc-13-1767-2019 4 July 2019 We present a new statistical model for converting snow depths to water equivalent. The only variables required are snow depth, day of year, and location. We use the location to look up climatological parameters such as mean winter precipitation and mean temperature difference (difference between hottest month and coldest month). The model is simple by design so that it can be applied to depth measurements anywhere, anytime. The model is shown to perform better than other widely used approaches. Read more
Emission of trace gases and aerosols from biomass burning – an updated assessment Atmospheric Chemistry and Physics DOI 10.5194/acp-19-8523-2019 4 July 2019 Biomass burning is one of the largest sources of atmospheric pollutants worldwide. This paper presents an up-to-date compilation of emission factors for over 120 trace gas and aerosol species from the different forms of open vegetation fires and domestic biofuel use, based on an analysis of over 370 published studies. Using these emission factors and current global burning activity data, the annual emissions of important species released by the various types of biomass burning are estimated. Read more
Mid-Holocene climate change over China: model–data discrepancy Climate of the Past DOI 10.5194/cp-15-1223-2019 2 July 2019 The mid-Holocene has been an excellent target for comparing models and data. This work shows that, over China, all the ocean–atmosphere general circulation models involved in PMIP3 show a very large discrepancy with pollen data reconstruction when comparing annual and seasonal temperature. It demonstrates that to reconcile models and data and to capture the signature of seasonal thermal response, it is necessary to integrate non-linear processes, particularly those related to vegetation changes. Read more
Alluvial channel response to environmental perturbations: fill-terrace formation and sediment-signal disruption Earth Surface Dynamics DOI 10.5194/esurf-7-609-2019 1 July 2019 We performed seven physical experiments to explore terrace formation and sediment export from a braided alluvial river system that is perturbed by changes in water discharge, sediment supply, or base level. Each perturbation differently affects (1) the geometry of terraces and channels, (2) the timing of terrace formation, and (3) the transient response of sediment discharge. Our findings provide guidelines for interpreting fill terraces and sediment export from fluvial systems. Read more
Contrail cirrus radiative forcing for future air traffic Atmospheric Chemistry and Physics DOI 10.5194/acp-19-8163-2019 27 June 2019 The climate impact of air traffic is to a large degree caused by changes in cirrus cloudiness resulting from the formation of contrails. We use an atmospheric climate model with a contrail cirrus parameterization to investigate the climate impact of contrail cirrus for the year 2050. The strong increase in contrail cirrus radiative forcing due to the projected increase in air traffic volume cannot be compensated for by the reduction of soot emissions and by improvements in propulsion efficiency. Read more
Evaluating biases in filter-based aerosol absorption measurements using photoacoustic spectroscopy Atmospheric Measurement Techniques DOI 10.5194/amt-12-3417-2019 27 June 2019 This research project assesses biases in traditional, filter-based, aerosol absorption measurements by comparison to state-of-the-art, non-filter-based, or in situ, measurements. We assess biases in traditional absorption measurements for three main aerosol types, including dust and fresh and aged biomass burning aerosols. The main results of this study are that the traditional and state-of-the-art absorption measurements are well correlated and that biases in the former are up to 45 %. Read more
Detecting layer height of smoke aerosols over vegetated land and water surfaces via oxygen absorption bands: hourly results from EPIC/DSCOVR in deep space Atmospheric Measurement Techniques DOI 10.5194/amt-12-3269-2019 20 June 2019 Detecting aerosol layer height from space is challenging. The traditional method relies on active sensors such as lidar that provide the detailed vertical structure of the aerosol profile but is costly with limited spatial coverage (more than 1 year is needed for global coverage). Here we developed a passive remote sensing technique that uses backscattered sunlight to retrieve smoke aerosol layer height over both water and vegetated surfaces from a sensor 1.5 million kilometers from the Earth. Read more
Technical note: A microcontroller-based automatic rain sampler for stable isotope studies Hydrology and Earth System Sciences DOI 10.5194/hess-23-2637-2019 19 June 2019 Most commercial automatic rain samplers are costly and do not prevent evaporation from the collection bottles. Hence, we have developed a microcontroller-based collector enabling timer-actuated integral rain sampling. The simple, low-cost device is robust and effectively minimizes post-sampling evaporation. The excellent performance of the collector during an evaporation experiment in a lab oven suggests that even multi-week field deployments in warm climates are feasible. Read more
Induced seismicity in geologic carbon storage Solid Earth DOI 10.5194/se-10-871-2019 19 June 2019 To meet the goal of the Paris Agreement to limit temperature increase below 2 ºC, geologic carbon storage (GCS) will be necessary at the gigatonne scale. But to successfully deploy GCS, seismicity induced by CO2injection should be controlled and maintained below a threshold that does not generate nuisances to the population. We conclude that felt induced seismicity can be minimized provided that a proper site characterization, monitoring and pressure management are performed. Read more
Aerosol pH and its driving factors in Beijing Atmospheric Chemistry and Physics DOI 10.5194/acp-19-7939-2019 17 June 2019 Aerosol acidity plays a key role in secondary aerosol formation. To provide a more comprehensive reference for aerosol pH and a basis for controlling secondary aerosol generation, this study used the latest data covering four seasons and different particle sizes to obtain the characteristics of aerosol pH and explore the main factors affecting aerosol pH and gas–particle partitioning in the Beijing area. Read more
Including the efficacy of land ice changes in deriving climate sensitivity from paleodata Earth System Dynamics DOI 10.5194/esd-10-333-2019 14 June 2019 Processes causing the same global-average radiative forcing might lead to different global temperature changes. We expand the theoretical framework by which we calculate paleoclimate sensitivity with an efficacy factor. Applying the revised approach to radiative forcing caused by CO2and land ice albedo perturbations, inferred from data of the past 800 000 years, gives a new paleo-based estimate of climate sensitivity. Read more
A sampler for atmospheric volatile organic compounds by copter unmanned aerial vehicles Atmospheric Measurement Techniques DOI 10.5194/amt-12-3123-2019 13 June 2019 Volatile organic compound (VOC) emissions influence air quality and particulate distributions, particularly in major source regions such as the Amazon. A sampler for collecting VOCs from an unmanned aerial vehicle (UAV) is described. Field tests of its performance and an initial example data set collected in the Amazon are also presented. The low cost, ease of use, and maneuverability of UAVs give this method the potential to significantly advance knowledge of the spatial distribution of VOCs. Read more
Analysis of an extreme weather event in a hyper-arid region using WRF-Hydro coupling, station, and satellite data Natural Hazards and Earth System Sciences DOI 10.5194/nhess-19-1129-2019 13 June 2019 The work addresses the need for reliable precipitation forecasts in hyper-arid environments through state-of-the-art hydro-meteorological modeling. Accounting for land–atmosphere interactions in the applied model is shown to improve the accuracy of precipitation output. The chain of events controlling the soil moisture–precipitation feedback are diagnosed and verified by in situ observations and satellite data. Read more
Global distribution of methane emissions, emission trends, and OH concentrations and trends inferred from an inversion of GOSAT satellite data for 2010–2015 Atmospheric Chemistry and Physics DOI 10.5194/acp-19-7859-2019 12 June 2019 We use 2010–2015 satellite observations of atmospheric methane to improve estimates of methane emissions and their trends, as well as the concentration and trend of tropospheric OH (hydroxyl radical, methane’s main sink). We find overestimates of Chinese coal and Middle East oil/gas emissions in the prior estimate. The 2010–2015 growth in methane is attributed to an increase in emissions from India, China, and areas with large tropical wetlands. The contribution from OH is small in comparison. Read more
Responses of an abyssal meiobenthic community to short-term burial with crushed nodule particles in the south-east Pacific Biogeosciences DOI 10.5194/bg-16-2329-2019 6 June 2019 To elucidate the potential effects of crushed nodule particle deposition on abyssal meiobenthos, we covered abyssal soft sediment in the Peru Basin (4200 m depth) with approximately 2 cm of this nodule material for 11 d. About half of the meiobenthos migrated from the sediment into the added material, and nematode feeding type proportions in that added layer were altered. These results considerably contribute to our understanding of the short-term responses of deep-sea meiobenthos to burial. Read more
Aerosol size distributions during the Atmospheric Tomography Mission (ATom): methods, uncertainties, and data products Atmospheric Measurement Techniques DOI 10.5194/amt-12-3081-2019 6 June 2019 From 2016 to 2018 a NASA aircraft profiled the atmosphere from 180 m to ~12 km from the Arctic to the Antarctic over both the Pacific and Atlantic oceans. This program, ATom, sought to sample atmospheric chemical composition to compare with global climate models. We describe the how measurements of particulate matter were made during ATom, and show that the instrument performance was excellent. Data from this project can be used with confidence to evaluate models and compare with satellites. Read more
The Bortoluzzi Mud Volcano (Ionian Sea, Italy) and its potential for tracking the seismic cycle of active faults Solid Earth DOI 10.5194/se-10-741-2019 4 June 2019 The Ionian Sea in southern Italy is at the center of active convergence between the Eurasian and African plates, with many known Mw > 7.0 earthquakes. Here, a recently discovered mud volcano (called the Bortoluzzi Mud Volcano or BMV) was surveyed during the Seismofaults 2017 cruise (May 2017). The BMV is the active emergence of crustal fluids probably squeezed up during the seismic cycle. As such, the BMV may potentially be used to track the seismic cycle of active faults. Read more
Glacial CO2 decrease and deep-water deoxygenation by iron fertilization from glaciogenic dust Climate of the Past DOI 10.5194/cp-15-981-2019 4 June 2019 Proxy records of glacial oxygen change provide constraints on the contribution of the biological pump to glacial CO2 decrease. Here, we report our numerical simulation which successfully reproduces records of glacial oxygen changes and shows the significance of iron supply from glaciogenic dust. Our model simulations clarify that the enhanced efficiency of the biological pump is responsible for glacial CO2 decline of more than 30 ppm and approximately half of deep-ocean deoxygenation. Read more
Telling the boiling frog what he needs to know: why climate change risks should be plotted as probability over time Geoscience Communication DOI 10.5194/gc-2-95-2019 29 May 2019 Humanity’s situation with respect to climate change is sometimes likened to that of a frog in a slow-boiling pot of water. But are we telling the frog what he needs to know? Most climate science is communicated to governments in the form of predictions of what is most likely to happen. I argue it should instead answer the following questions: what is the worst that could happen, and how likely will that become as time goes by? The risks and need to act will then become much clearer to see. Read more
Impacts of Three Gorges Dam’s operation on spatial–temporal patterns of tide–river dynamics in the Yangtze River estuary, China Ocean Science DOI 10.5194/os-15-583-2019 28 May 2019 In this study, we assessed the impacts of the world’s largest dam, the Three Gorges Dam (TGD), on tide–river dynamics and concluded that the strongest impacts occurred during autumn and winter due to the TGD’s operation. The results obtained will hopefully enhance our understanding of the impacts of large-scale human interventions on estuarine hydrodynamics and guide effective and sustainable water management in the Yangtze River estuary and other estuaries with substantial freshwater discharge. Read more
Recrystallization processes, microstructure and crystallographic preferred orientation evolution in polycrystalline ice during high-temperature simple shear The Cryosphere DOI 10.5194/tc-13-1495-2019 27 May 2019 Ice mechanics is an important tool to better predict the response of glaciers or polar ice sheets to climate variations. Nevertheless our current predictive abilities are limited as the microscale mechanisms responsible for ice creep are poorly identified. We show in this study, using state-of-the-art experimental techniques, which recrystallization processes control ice deformation. This will allow realistic simulations, necessary to predict the long-term effects on ice landmasses. Read more
Photooxidants from brown carbon and other chromophores in illuminated particle extracts Atmospheric Chemistry and Physics DOI 10.5194/acp-19-6579-2019 17 May 2019 We measured hydroxyl radical (•OH), singlet oxygen (1O2*), and organic triplets (3C*) in illuminated aqueous particle extracts. After measuring the impact of dilution on oxidant concentrations, we extrapolated our results to predict them in ambient particles –1O2* and3C* concentrations appear to be greatly enhanced, while•OH appears largely unchanged. Two of these oxidants (1O2*,3C*) are not yet included in atmospheric models, and our results make it possible to include them in the future. Read more
Northern Hemisphere continental winter warming following the 1991 Mt. Pinatubo eruption: reconciling models and observations Atmospheric Chemistry and Physics DOI 10.5194/acp-19-6351-2019 15 May 2019 This study provides compelling new evidence that the surface winter warming observed over the Northern Hemisphere continents following the 1991 eruption of Mt. Pinatubo was, very likely, completely unrelated to the eruption. This result has implications for earlier eruptions, as the evidence presented here demonstrates that the surface signal of even the very largest known eruptions may be swamped by the internal variability at high latitudes. Read more
Time-lapse gravity and levelling surveys reveal mass loss and ongoing subsidence in the urban subrosion-prone area of Bad Frankenhausen, Germany Solid Earth DOI 10.5194/se-10-599-2019 13 May 2019 Subrosion, i.e. the underground leaching of soluble rocks, causes disastrous sinkhole events worldwide. We investigate the accompanying mass transfer using quarter-yearly time-lapse gravity campaigns over 4 years in the town of Bad Frankenhausen, Germany. After correcting for seasonal soil water content, we find evidence of underground mass loss and attempt to quantify its amount. This is the first study of its kind to prove the feasibility of this approach in an urban area. Read more
Quantifying variations in shortwave aerosol–cloud–radiation interactions using local meteorology and cloud state constraints Atmospheric Chemistry and Physics DOI 10.5194/acp-19-6251-2019 13 May 2019 Aerosols are released by natural and human activities. When aerosols encounter clouds they interact in what is known as the indirect effect. Brighter clouds are expected due to the microphysical response; however, certain environments can trigger a modified response. Limits on the stability, humidity, and cloud thickness are applied regionally to investigate local cloud responses to aerosol, resulting in a range of indirect effects that would result in significant cooling or slight warming. Read more
Using a coupled agent-based modeling approach to analyze the role of risk perception in water management decisions Hydrology and Earth System Sciences DOI 10.5194/hess-23-2261-2019 10 May 2019 This study applies a two-way coupled agent-based model (ABM) with a river-reservoir management model (RiverWare) to analyze the role of risk perception in water management decisions using the Bayesian inference mapping joined with the cost–loss model. The calibration results capture the dynamics of historical irrigated area and streamflow changes and suggest that the proposed framework improves the representation of human decision-making processes compared to conventional rule-based ABMs. Read more
Heterogeneous sulfate aerosol formation mechanisms during wintertime Chinese haze events: air quality model assessment using observations of sulfate oxygen isotopes in Beijing Atmospheric Chemistry and Physics DOI 10.5194/acp-19-6107-2019 8 May 2019 Sulfate is a key species contributing to particle formation and growth during wintertime Chinese haze events. This study combines observations and modeling of oxygen isotope signatures in sulfate aerosol to investigate its formation mechanisms, with a focus on heterogeneous production on aerosol surface via H2O2, O3, and NO2 and trace metal catalyzed oxidation. Contributions from different formation pathways are presented. Read more
Reciprocal bias compensation and ensuing uncertainties in model-based climate projections: pelagic biogeochemistry versus ocean mixing Biogeosciences DOI 10.5194/bg-16-1865-2019 6 May 2019 Anthropogenic greenhouse gas emissions trigger complex climate feedbacks. Output form Earth system models provides a basis for related political decision-making. One challenge is to arrive at reliable model parameter estimates for the ocean biogeochemistry module. We illustrate pitfalls through which flaws in the ocean module are masked by wrongly tuning the biogeochemistry and discuss ensuing uncertainties in climate projections. Read more
Summertime precipitation extremes in a EURO-CORDEX 0.11° ensemble at an hourly resolution Natural Hazards and Earth System Sciences DOI 10.5194/nhess-19-957-2019 2 May 2019 A state-of-the-art regional climate model ensemble for Europe is investigated for extreme precipitation intensities. The models poorly reproduce short duration events of less than a few hours. Further, there is poor connection to some known hotspots for extreme cases. The model performance is much improved at 12 h durations. Projected future increases scale with seasonal mean temperature change, within a range from a few percent to over 10 percent per degree Celsius. Read more
Vertical and horizontal distribution of submicron aerosol chemical composition and physical characteristics across northern India during pre-monsoon and monsoon seasons Atmospheric Chemistry and Physics DOI 10.5194/acp-19-5615-2019 30 April 2019 Our study, for the first time, presents measurements of aerosol chemical composition and physical characteristics across northern India in the pre-monsoon and monsoon seasons of 2016 using the FAAM BAe-146 UK research aircraft. Across northern India, an elevated aerosol layer dominated by sulfate aerosol exists that diminishes with monsoon arrival. The Indo-Gangetic Plain (IGP) boundary layer is dominated by organics, whereas outside the IGP sulfate dominates with increased scattering aerosol. Read more
Controls on spatial and temporal variability in streamflow and hydrochemistry in a glacierized catchment Hydrology and Earth System Sciences DOI 10.5194/hess-23-2041-2019 24 April 2019 Hydrometric and geochemical dynamics are controlled by interplay of meteorological conditions, topography and geological heterogeneity. Nivo-meteorological indicators (such as global solar radiation, temperature and decreasing snow depth) explain monthly conductivity and isotopic dynamics best. These insights are important for better understanding hydrochemical responses of glacierized catchments under a changing cryosphere. Read more
Winter tourism under climate change in the Pyrenees and the French Alps: relevance of snowmaking as a technical adaptation The Cryosphere DOI 10.5194/tc-13-1325-2019 24 April 2019 This study investigates the snow reliability of 175 ski resorts in the Pyrenees (France, Spain and Andorra) and the French Alps under past and future conditions (1950–2100) using state-of-the-art climate projections and snowpack modelling accounting for snow management, i.e. grooming and snowmaking. The snow reliability of ski resorts shows strong elevation and regional differences, and our study quantifies changes in snow reliability induced by snowmaking under various climate scenarios. Read more
Uncertainty quantification of the multi-centennial response of the Antarctic ice sheet to climate change The Cryosphere DOI 10.5194/tc-13-1349-2019 24 April 2019 Using probabilistic methods, we quantify the uncertainty in the Antarctic ice-sheet response to climate change over the next millennium under the four RCP scenarios and parametric uncertainty. We find that the ice sheet is stable in RCP 2.6 regardless of parametric uncertainty, while West Antarctica undergoes disintegration in RCP 8.5 almost regardless of parametric uncertainty. We also show a high sensitivity of the ice-sheet response to uncertainty in sub-shelf melting and sliding conditions. Read more
ESD Ideas: Propagation of high-frequency forcing to ice age dynamics Earth System Dynamics DOI 10.5194/esd-10-257-2019 24 April 2019 We demonstrate here that nonlinear character of ice sheet dynamics, which was derived naturally from the conservation laws, is an effective means for propagating high-frequency forcing upscale. Read more
Modelling the future evolution of glaciers in the European Alps under the EURO-CORDEX RCM ensemble The Cryosphere DOI 10.5194/tc-13-1125-2019 9 April 2019 Glaciers in the European Alps play an important role in the hydrological cycle, act as a source for hydroelectricity and have a large touristic importance. We model the future evolution of all glaciers in the Alps with a novel model that combines both ice flow and melt processes. We find that under a limited warming scenario about one-third of the present-day ice volume will still be present by the end of the century, while under strong warming more than 90 % of the volume will be lost by 2100. Read more
A new description of probability density distributions of polar mesospheric clouds Atmospheric Chemistry and Physics DOI 10.5194/acp-19-4685-2019 8 April 2019 In this paper we present a new description of statistical probability density functions (pdfs) of polar mesospheric clouds (PMC). We derive a new class of pdfs that describes successfully the probability statistic of ALOMAR lidar observations of different ice parameters. As a main advantage the new method allows us to connect different observational PMC distributions of lidar and satellite data, and also to compare with distributions from ice model studies. Read more
Pathways of ice-wedge degradation in polygonal tundra under different hydrological conditions The Cryosphere DOI 10.5194/tc-13-1089-2019 4 April 2019 We studied the stability of ice wedges (massive bodies of ground ice in permafrost) under recent climatic conditions in the Lena River delta of northern Siberia. For this we used a novel modelling approach that takes into account lateral transport of heat, water, and snow and the subsidence of the ground surface due to melting of ground ice. We found that wetter conditions have a destabilizing effect on the ice wedges and associated our simulation results with observations from the study area. Read more
Terrainbento 1.0: a Python package for multi-model analysis in long-term drainage basin evolution Geoscientific Model Development DOI 10.5194/gmd-12-1267-2019 3 April 2019 Terrainbento 1.0 is a Python package for modeling the evolution of the surface of the Earth over geologic time (e.g., thousands to millions of years). Despite many decades of effort by the geomorphology community, there is no one established governing equation for the evolution of topography. Terrainbento 1.0 thus provides 28 alternative models that support hypothesis testing and multi-model analysis in landscape evolution. Read more
Permafrost nitrous oxide emissions observed on a landscape scale using the airborne eddy-covariance method Atmospheric Chemistry and Physics DOI 10.5194/acp-19-4257-2019 3 April 2019 As frozen soil, called permafrost, increasingly thaws over the years, scientists have put much effort into understanding how this may increase carbon emissions, which would exacerbate climate change. Our work supports the emerging view that these efforts should also include nitrous oxide (N2O), a more potent greenhouse gas. Using a low-flying aircraft to study thousands of acres of Alaskan permafrost, we observed average N2O emissions higher than typically assumed for regions such as this. Read more
Devito (v3.1.0): an embedded domain-specific language for finite differences and geophysical exploration Geoscientific Model Development DOI 10.5194/gmd-12-1165-2019 27 March 2019 This paper presents Devito, a Python-based software. The aim of this software is to provide a high-level simple interface to users for the description and discretization of the mathematical definition of the physics. This research initially started as an attempt to improve research time, portability, and performance in exploration geophysics. We present the latest version of the software that is already making an impact in academics and industry. Read more
Carbon cycling in the North American coastal ocean: a synthesis Biogeosciences DOI 10.5194/bg-16-1281-2019 27 March 2019 We review and synthesize available information on coastal ocean carbon fluxes around North America (NA). There is overwhelming evidence, compiled and discussed here, that the NA coastal margins act as a sink. Our synthesis shows the great diversity in processes driving carbon fluxes in different coastal regions, highlights remaining gaps in observations and models, and discusses current and anticipated future trends with respect to carbon fluxes and acidification. Read more
The 4.2 ka BP Event in the Mediterranean region: an overview Climate of the Past DOI 10.5194/cp-15-555-2019 27 March 2019 The Mediterranean region has returned some of the clearest evidence of a climatically dry period occurring approximately 4200 years ago. We reviewed selected proxies to infer regional climate patterns between 4.3 and 3.8 ka. Temperature data suggest a cooling anomaly, even if this is not uniform, whereas winter was drier, along with dry summers. However, some exceptions to this prevail, where wetter condition seems to have persisted, suggesting regional heterogeneity. Read more