Electron pairing in mirror modes: surpassing the quasi-linear limit Annales Geophysicae DOI 10.5194/angeo-37-971-2019 8 November 2019 The mirror mode starts as a zero-frequency ion fluid instability and saturates quasi-linearly at very low magnetic level, while forming extended magnetic bubbles. These trap the adiabatically bouncing electron component which forms pairs near the mirror points. The large pair anisotropy causes further growth beyond quasilinear level. Including pressure equilibrium gives and estimate of the required pair density. Read more
Microbial community composition and abundance after millennia of submarine permafrost warming Biogeosciences DOI 10.5194/bg-16-3941-2019 8 November 2019 Permafrost temperatures increased substantially at a global scale, potentially altering microbial assemblages involved in carbon mobilization before permafrost thaws. We used Arctic Shelf submarine permafrost as a natural laboratory to investigate the microbial response to long-term permafrost warming. Our work shows that millennia after permafrost warming by > 10 °C, microbial community composition and population size reflect the paleoenvironment rather than a direct effect through warming. Read more
The biophysics, ecology, and biogeochemistry of functionally diverse, vertically and horizontally heterogeneous ecosystems: the Ecosystem Demography model, version 2.2 – Part 1: Model description Geoscientific Model Development DOI 10.5194/gmd-12-4309-2019 8 November 2019 Our paper describes the Ecosystem Demography model. This computer program calculates how plants and ground exchange heat, water, and carbon with the air, and how plants grow, reproduce and die in different climates. Most models simplify forests to an average big tree. We consider that tall, deep-rooted trees get more light and water than small plants, and that some plants can with shade and drought. This diversity helps us to better explain how plants live and interact with the atmosphere. Read more
The biophysics, ecology, and biogeochemistry of functionally diverse, vertically and horizontally heterogeneous ecosystems: the Ecosystem Demography model, version 2.2 – Part 2: Model evaluation for tropical South America Geoscientific Model Development DOI 10.5194/gmd-12-4347-2019 29 October 2019 The Ecosystem Demography model calculates the fluxes of heat, water, and carbon between plants and ground and the air, and the life cycle of plants in different climates. To test if our calculations were reasonable, we compared our results with field and satellite measurements. Our model predicts well the extent of the Amazon forest, how much light forests absorb, and how much water forests release to the air. However, it must improve the tree growth rates and how fast dead plants decompose. Read more
Modeling forest plantations for carbon uptake with the LPJmL dynamic global vegetation model Earth System Dynamics DOI 10.5194/esd-10-617-2019 29 October 2019 We developed a computer model that simulates forests plantations at global scale and how fast such forests can take up CO2from the atmosphere. Using this new model, we performed simulations for a scenario in which a large fraction (14 %) of global croplands and pastures are either converted to planted forests or natural forests. We find that planted forests take up CO2substantially faster than natural forests and are therefore a viable strategy for reducing climate change. Read more
Contrasting thinning patterns between lake- and land-terminating glaciers in the Bhutanese Himalaya The Cryosphere DOI 10.5194/tc-13-2733-2019 29 October 2019 We investigate thickness change of Bhutanese glaciers during 2004–2011 using repeat GPS surveys and satellite-based observations. The thinning rate of Lugge Glacier (LG) is > 3 times that of Thorthormi Glacier (TG). Numerical simulations of ice dynamics and surface mass balance (SMB) demonstrate that the rapid thinning of LG is driven by both negative SMB and dynamic thinning, while the thinning of TG is minimised by a longitudinally compressive flow regime. Read more
Ensemble models from machine learning: an example of wave runup and coastal dune erosion Natural Hazards and Earth System Sciences DOI 10.5194/nhess-19-2295-2019 29 October 2019 Wave runup is important for characterizing coastal vulnerability to wave action; however, it is complex and uncertain to predict. We use machine learning with a high-resolution dataset of wave runup to develop an accurate runup predictor that includes prediction uncertainty. We show how uncertainty in wave runup predictions can be used practically in a model of dune erosion to make ensemble predictions that provide more information and greater predictive skill than a single deterministic model. Read more
Geologic and geomorphic controls on rockfall hazard: how well do past rockfalls predict future distributions? Natural Hazards and Earth System Sciences DOI 10.5194/nhess-19-2249-2019 11 October 2019 Here we evaluate geologic, geomorphic, and anthropogenic controls on rockfall hazard and highlight the complexity of interpreting future rockfall hazard based on former boulder distributions. To evaluate how past rockfall deposits relate to contemporary rockfall hazard, we mapped then compared the locations, physical characteristics, and lithologies of rockfall boulders deposited during the 2010–2011 Canterbury earthquake sequence (n= 185) with their prehistoric counterparts (n= 1093). Read more
Relative impact of aerosol, soil moisture, and orography perturbations on deep convection Atmospheric Chemistry and Physics DOI 10.5194/acp-19-12343-2019 7 October 2019 This study addresses the relative impact of orography, soil moisture, and aerosols on precipitation over Germany in different weather regimes. We find that the impact of these perturbations is higher for weak than for strong large-scale forcing. Furthermore, aerosols and soil moisture are both of similar importance for precipitation forecasting, which indicates that their inclusion in operational ensemble forecasting should be assessed in the future. Read more
Mapping landscape connectivity as a driver of species richness under tectonic and climatic forcing Earth Surface Dynamics DOI 10.5194/esurf-7-895-2019 1 October 2019 Mountainous landscapes have long been recognized as potential drivers for genetic drift, speciation, and ecological resilience. We present a novel approach that can be used to assess and quantify drivers of biodiversity, speciation, and endemism over geological time. Using coupled climate–landscape models, we show that biodiversity under tectonic and climatic forcing relates to landscape dynamics and that landscape complexity drives species richness through orogenic history. Read more
Understanding the spatiotemporal development of human settlement in hurricane-prone areas on the US Atlantic and Gulf coasts using nighttime remote sensing Natural Hazards and Earth System Sciences DOI 10.5194/nhess-19-2141-2019 1 October 2019 This study examined the spatiotemporal dynamics of nighttime satellite-derived human settlement in response to different levels of hurricane proneness in a period from 1992 to 2013. It confirms theSnow Belt-to-Sun BeltUS population shift trend. The results also suggest that hurricane-exposed human settlement has grown in extent and area, as more hurricane exposure has experienced a larger increase rate in settlement intensity. Read more
Benchmarking the predictive capability of hydrological models for river flow and flood peak predictions across over 1000 catchments in Great Britain Hydrology and Earth System Sciences DOI 10.5194/hess-23-4011-2019 30 September 2019 We evaluated four hydrological model structures and their parameters on over 1100 catchments across Great Britain, considering modelling uncertainties. Models performed well for most catchments but failed in parts of Scotland and south-eastern England. Failures were often linked to inconsistencies in the water balance. This research shows what conceptual lumped models can achieve, gives insights into where and why these models may fail, and provides a benchmark of national modelling capability. Read more
Physical constraints for respiration in microbial hotspots in soil and their importance for denitrification Biogeosciences DOI 10.5194/bg-16-3665-2019 27 September 2019 A combination of gas chromatography and X-ray CT reveals the microscale processes that govern soil respiration. Aerobic and anaerobic respiration in microbial hotspots depends not only on the quality and quantity of soil organic matter, but also on the spatial distribution of hotspots. Denitrification kinetics are mainly governed by hotspot architecture due to local competition for oxygen during growth. Cumulative behavior is mainly governed by water saturation due to the overall supply with O2. Read more
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
Improving the understanding of flood risk in the Alsatian region by knowledge capitalization: the ORRION participative observatory Natural Hazards and Earth System Sciences DOI 10.5194/nhess-19-1653-2019 7 August 2019 The article presents the Alsatian regional flood risk observatory ORRION, a participative online platform on which information is shared between individuals, stakeholders, engineers, and scientists. This maximizes knowledge capitalization and contributes to building a common knowledge base for flood risk. From this information, long chronicles of floods are derived for the Rhine, and most of its main Alsatian tributaries and their main characteristics are identified and analysed. Read more
Past climate and continentality inferred from ice wedges at Batagay megaslump in the Northern Hemisphere’s most continental region, Yana Highlands, interior Yakutia Climate of the Past DOI 10.5194/cp-15-1443-2019 2 August 2019 To reconstruct past winter climate, we studied ice wedges at two sites in the Yana Highlands, interior Yakutia (Russia), the most continental region of the Northern Hemisphere. Our ice wedges of the upper ice complex unit of the Batagay megaslump and a river terrace show much more depleted stable-isotope compositions than other study sites in coastal and central Yakutia, reflecting lower winter temperatures and a higher continentality of the study region during Marine Isotope Stages 3 and 1. Read more
A salinity module for SWAT to simulate salt ion fate and transport at the watershed scale Hydrology and Earth System Sciences DOI 10.5194/hess-23-3155-2019 31 July 2019 Salinity is one of the most common water quality threats in river basins and irrigated regions worldwide. Available watershed models, however, do not simulate the fate and transport of salt species. This paper presents a modified version of the popular SWAT watershed model that simulates the transport of major salt ions in a watershed system. Salt is transported via surface runoff, soil percolation, groundwater flow, and streamflow. The model can be used in salt-affected watersheds worldwide. Read more
Global soil–climate–biome diagram: linking surface soil properties to climate and biota Biogeosciences DOI 10.5194/bg-16-2857-2019 25 July 2019 Surface soils interact strongly with both climate and biota and provide fundamental ecosystem services. However, the quantitative linkages between soil, climate, and biota remain unclear at a global scale. By compiling a large global soil database, we mapped eight major soil properties based on machine learning algorithms and developed a global soil–climate–biome diagram. Our results suggest shifts in soil properties under global climate and land cover change. Read more
Assessing the characteristics and drivers of compound flooding events around the UK coast Hydrology and Earth System Sciences DOI 10.5194/hess-23-3117-2019 23 July 2019 Flooding can arise from multiple sources, including waves, extreme sea levels, rivers, and severe rainfall. When two or more sources combine, the consequences can be greatly multiplied. We find the potential for the joint occurrence of extreme sea levels and river discharge to be greater on the western coast of the UK compared to the eastern coast. This is due to the weather conditions generating each flood source around the UK. These results will help increase our flood forecasting ability. Read more
Early instrumental meteorological measurements in Switzerland Climate of the Past DOI 10.5194/cp-15-1345-2019 22 July 2019 The 18th and early 19th centuries saw pronounced climatic variations with impacts on the environment and society. Although instrumental meteorological data for that period exist, only a small fraction has been the subject of research. This study provides an overview of early instrumental meteorological records in Switzerland resulting from an archive survey and demonstrates the great potential of such data. It is accompanied by the online publication of the imaged data series and metadata. Read more
Converging photospheric vortex flows close to the polarity inversion line of a fully emerged active region Annales Geophysicae DOI 10.5194/angeo-37-603-2019 22 July 2019 We describe a technique used to locate and classify critical points in 2-D flow fields at the solar photosphere obtained from the evolution of the line-of-sight magnetic field in a region close to the magnetic polarity inversion line of a fully emerged active region. We apply this technique to locate a particular kind of critical point associated to vortex flows, which are considered important, since they can twist and interweave the foot points of flux tubes and generate magnetic reconnection. Read more
Towards monitoring localized CO2 emissions from space: co-located regional CO2 and NO2 enhancements observed by the OCO-2 and S5P satellites Atmospheric Chemistry and Physics DOI 10.5194/acp-19-9371-2019 22 July 2019 The quantification of anthropogenic emissions with current CO2 satellite sensors is difficult, but NO2 is co-emitted, making it a suitable tracer of recently emitted CO2. We analyze enhancements of CO2 and NO2 observed by OCO-2 and S5P and estimate the CO2plume cross-sectional fluxes that we compare with emission databases. Our results demonstrate the usefulness of simultaneous satellite observations of CO2 and NO2 as envisaged for the European Copernicus anthropogenic CO2 monitoring mission Read more
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