bluuebunny/crossref_metadata_2025 huggingface dataset:
Are Cryosphere-Driven Feedbacks a Requisite for Abrupt Climate Events?
Authors: Holmes Dakota , Morley Audrey
Published: March 2020

Abrupt climate events are generally believed to be characteristic of glacial (intermediate-to-large cryosphere) climate states, requiring either sizeable ice-sheets or large freshwater pulses to act as triggers for abrupt climate changes to occur. Amplification occurs when these triggers bear upon the Atlantic Meridional Overturning Circulation (AMOC). However, the focus on glacial climate states in abrupt climate change research has led to an underrepresentation of research into interglacial periods. It thus remains unclear whether high-magnitude climate variability requires large cryosphere-driven feedbacks or whether it can also occur under low ice conditions. Here we present a high resolution analysis of surface and deep water components of the AMOC spanning the transition from Marine Isotope Stage (MIS) 19c to 19a to test if orbital boundary conditions similar to our current Holocene can accommodate abrupt climate events. Sediment core DSDP 610B (53°13.297N, 18°53.213W), located approximately 700-km west of Ireland, was specifically chosen due to its high sedimentation rate during interglacial periods, excellent core recovery over the Quaternary and its unique geographical location. Above the core site, the dominant oceanographic feature is the North Atlantic Current and at 2417-m water depth, 610B is influenced by Wyville Thomson Overflow Water flowing southwards. A multiproxy approach including paired grain size analysis, planktic foraminifer assemblage counts, and ice-rafted debris counts within the same samples allows us to resolve the timing between both surface and bottom components of the AMOC and their response to abrupt climate events during MIS-19 in the eastern subpolar gyre. This study is societally relevant as future freshwater inputs from a melting Greenland ice sheet may impact ocean circulation, potentially causing shifts in climate for many European countries.
Assessing the Carbon Intensity of Low-Enthalpy Deep Geothermal Heat
Authors: McCay Alistair , Roberts Jen , Feliks Michael
Published: March 2020

Decarbonising heating presents a significant societal challenge. Deep geothermal energy is widely recognised as a source of low carbon heat. However, to date there has been no assessment of the carbon intensity of heat from low-enthalpy deep geothermal as previous studies have focussed on geothermal power or higher enthalpy heat. Further, there is currently no established method for assessing the CO2 emissions reduction from implementing a deep geothermal heating scheme.

To address these gaps, we performed a life cycle assessment of greenhouse gas emissions relating to a typical deep geothermal heat system to (i) calculate the carbon intensity of geothermal heat (ii) identify the factors that most affect these values (iii) consider the carbon abated if geothermal heat substitutes conventional heating sources and (iv) set a benchmark methodology that future projects can adapt and apply to assess and enhance the carbon emissions reduction offered by geothermal heat development in the UK and internationally.

In the absence of an established deep geothermal heat system in the UK, to inform our work we adopted parameters from a feasibility study for a potential geothermal heat system in Banchory, Scotland. The Banchory project aimed to deliver heat to a network sourced from 2-3 km deep in a radiothermal granite where temperatures were predicted to be 70-90 °C. We assumed a 30 year project lifetime and that the heat system operation was powered by the UK electricity grid which was decarbonising over this period.

Our analysis found that the carbon intensity of deep geothermal heat is 9.7 - 14.0 kg(CO2e)/MWhth. This is ~5% of the value for natural gas heating. The carbon intensity is sensitive to several factors, and so the carbon intensity of deep geothermal heat could be reduced further by: replacing diesel fuelled drilling apparatus with natural gas or electricity powered hardware; decarbonise the power grid more rapidly than forecast; or substitute mains power with local renewable electricity to power pumps – or decarbonising the electricity grid faster or deeper; source lower carbon steel and cement; design projects to minimise land use change emissions.

Overall, our study provides quantitative evidence that deep geothermal systems can produce long term very low carbon heat that is compatible with net-zero, even for low enthalpy geothermal resources.
Towards standardized experimentation in soil research – a synthetic ecology approach
Authors: Schmidt Hannes , Horak Julia , Kits K. Dimitri , Canarini Alberto , Hadziabdic Leila , Richter Andreas
Published: March 2020

Soils contain a vast diversity of microorganisms including millions of cells and thousands of species. Many of those species encode for similar functions which is known as functional redundancy. From an ecosystem perspective, it remains unknown how many of such species are contributing to processes and are actually necessary to perform functions. Not knowing about the number and type of taxa of a soil sample a priori, let alone of the interaction between those taxa or the chemical environment of their habitats, hampers the reproducibility of soil ecological research and renders a targeted experimentation virtually impossible. This is one of the most important reasons why linking microbial identity to processes at the soil scale has proven to be everything but easy.

A promising avenue to overcome these limitations are model ecosystems that allow to identify principles of community functioning via standardised experimentation. Here, we will present a synthetic ecology approach using artificial soil mimicking the structural and chemical complexity of a soil and a synthetic microbial community to investigate microbial functioning in soil. Our approach includes genome-guided in silico design of synthetic communities to reproduce the functionality of soil heterotrophic bacteria and fungi, while largely decreasing the number of individual taxa for laboratory experimentation.

Initial experiments suggested that our synthetic community was able to establish in artificial soil and sterilized natural soil and to perform a range of simple soil processes, as evident through potential enzymatic activities, heterotrophic respiration, and changes in organic and inorganic soil components. Molecular analysis of the community composition over time demonstrated high similarities of the established community among replicates, indicating low effects of stochasticity on community assembly, a major requirement for reproducible experimentation. These promising preliminary data indicate that our model system could indeed represent the experimental platform for targeted experimentation in soil ecological research in the future.
Hyper-Spectral Imaging for Earth Observation Applications
Authors: Zempila Melina Maria , Hamilton Michelle , Mortimer Hugh
Published: March 2020

In this study, we present a hyper-spectral imaging (HSI) system that focuses on the spectral window 470-970 nm and meets the demands of static sampling and remote sensing when mounted on an Unmanned Aerial System (UAS).

The system comprises two HS cameras, a compact industrial PC and a battery pack. It has a total weight of <1.8kg, including the bracket for mounting to an active DJI Ronin gimbal. A labview interface was also developed to collect, process and analyse the images from the two HS cameras. The software has the ability to set the parameters for the cameras’ exposure times and capture frequency, while it can provide the digital counts at a single point of the image or the averaged counts over a rectangular area of the image. For the purposes of aerial applications, the program provides the ability of delayed start and sequentially image capture.

For the calibration of the raw HS images, an offline workflow is developed to derive absolute reflectance values. The processing chain includes dark and vignetting correction, spectral response characterization, digital number to reflectance conversion and hyperspectral data cube reconstruction.

The system has been already deployed in several in house studies: detection of dothistroma in Scots pine needles, starch detection in apples and bananas, and avocados maturity indication, while aerial imagery was also acquired during field campaigns in the UK and China aiming to create a tree species distribution map and to early identify tree health issues.

The development of the system is dynamic as technology is moving forward and the demand for light-weighted multi-sensor UAS surveys is increased during the last decade. Furthermore, the calibration processes and data analysis techniques are constantly updated to meet international requirements and push the accuracy of the products to the highest standards.
Timing environmental perturbations across the Cretaceous – Paleogene boundary in the Boreal Realm (N. Denmark)
Authors: Møller Sarah D. , Adatte Thierry , Bjerrum Christian J. , Thibault Nicolas
Published: March 2020

The Cretaceous-Paleogene boundary (K-PgB) interval of Denmark has been the subject of numerous contributions for understanding this mass extinction, focusing essentially on the famous coastal exposures of Stevns Klint (Sjælland). Although less popular, exposures of the K-PgB are also known in northern Jutland (NW Denmark) and have been the subject of a few contributions on their macro- and microfaunal content. Through an integrated study of the section of Nye Kløv (biostratigraphy and high-resolution stable isotope stratigraphy), we show here that the KPgB interval in northern Jutland presents the double advantage of (1) being continuous across the latest Maastrichtian to early Paleogene (contrary to Stevns Klint sections that bear several discontinuities such as prominent hardgrounds) and (2) bearing well-preserved macro- and microfossil assemblages, and isotopic trends in carbon and oxygen. Bulk carbonate oxygen isotopes delineate with great precision temperatures trends across the KPgB interval with cyclic oscillations that faithfully reproduce trends of the La2010b astronomical solution, hence allowing for an astronomical calibration of the section. The orbital calibration of the KPgB in Nye Kløv points to an age of 66.01 Ma. Our study delineates a Deccan warming optimum at 66.25 Ma corresponding to the deposition of the Kjølby Gaard marl, a distinct marly layer that can be traced throughout the North Sea. A clear shift toward the end-Maastrichtian cooling follows the Deccan warming at 66.1 Ma and precedes a last pulse of warming immediately below the boundary at 66.02 Ma. The earliest Danian is characterized by lower temperatures up until 65.88 Ma, after which temperatures resume to the same range as those of the Deccan warming, albeit with strong oscillations that reflect pacing by the short-eccentricity. This shift toward much warmer temperatures is associated with a first negative excursion in carbon isotopes. A second marked negative excursion in carbon isotopes occurs at 65.65 Ma and taken all-together, the overall warm interval comprising these two carbon isotope excursions reflects the local expression of the Dan-C2 hyperthermal event. Orbital calibration of the Nye Kløv section also allowed us to determine the timing of the recovery in the benthic community in the Boreal Chalk Sea, marked by an increase in skeletal fragments and brachiopod diversity, which occurred at 65.8 Ma, hence in conjunction with the Dan-C2 event.
Results from a comparison of HCN measurements and Lagrangian backtrajectory analyses in the Asian Summer Monsoon Anticyclone
Authors: Li Yun , Vogel Bärbel , Plöger Felix , Bucci Silvia , Legras Bernard , Viciani Silvia , D'Amato Francesco , Stroh Fred
Published: March 2020

The StratoClim aircraft field campaign took place from Kathmandu, Nepal, in summer 2017 in
order to study the atmospheric composition, chemistry, and dynamics in the Asian Summer
Monsoon Anticyclone (ASMA) which is known to transport surface emissions to the mid-latitude
lower stratosphere and the stratosphere worldwide. Hydrogen cyanide (HCN) which is primarily
emitted from biomass burning and has a UTLS lifetime on the order of 1-2 years is a good tracer for
biomass burning import into the lower and free stratosphere.
HCN in the ASM Upper Troposphere and Lower Stratosphere (UTLS) was measured in-situ
employing the Chemical-Ionization Time-of-Flight Mass Spectrometer FUNMASS on board the
high-altitude research aircraft M55-Geophysica. The observed HCN mixing ratios in and above the
ASMA exhibit interesting vertical and horizontal signatures around the tropopause as well as in the
LS probably resulting from convective activity or air mass origin (AMO). We here compare
measured HCN to Lagrangian simulations by the ClaMS and TRACZILLA models which employ
two different approaches to represent higher-reaching convective events. The simulations succeed to
track some of the observed HCN features back to convective activity or AMO. The quality of the
reproduction and further outcomes on the atmospheric relevance will be discussed in the
presentation.
The moisture budget of tropical cyclones: large scale environmental constraints and sensitivity to model horizontal resolution
Authors: Vanniere Benoit , Roberts Malcolm , Vidale Pier Luigi , Hodges Kevin , Demory Marie-Estelle
Published: March 2020

Previous studies have shown that, the number, intensity and structure of simulated tropical cyclones (TC) in climate models get closer to the observations as the horizontal resolution is increased. However, the sensitivity of tropical cyclone precipitation and moisture budget to changes in resolution has received less attention. In this study, we use the five-model ensemble from project PRIMAVERA/HighResMIP to investigate the systematic changes associated with the water budget of tropical cyclones in a range of horizontal resolutions from 1º to 0.25º. Our results show that despite a large change in the distribution of TC intensity with resolution, the distribution of precipitation per TC does not change significantly. This result is explained by the large scale balance which characterises the moisture budget of TCs, i.e. radii of ~15º a scale that low and high resolution models represent equally well. The wind profile is found to converge between low and high resolutions for radii > 5º, resulting in a moisture flux convergence into the TC with similar magnitude at low and high resolutions. In contrast to precipitation per TC, the larger TC intensity at higher resolution is explained by the larger surface latent heat flux near the center of the storm, which leads to an increase in equivalent potential temperature and warmer core anomalies, despite representing a negligible contribution to the moisture budget. We discuss the complication arising from the choice of the tracking algorithm when assessing the impact of model resolution and the implications of such a constraint on the TC moisture budget in the context of climate change.
Mapping altimetry in the forthcoming SWOT era by back-and-forth nudging the quasi-geostrophic dynamics
Authors: Le Guillou Florian , Metref Sammy , Ballarotta Maxime , Ubelmann Clément , Cosme Emmanuel , Le Sommer Julien , Verron Jacques
Published: March 2020

For 20 years, ocean surface topography maps, essential for understanding the ocean circulation, have been built by statistically interpolating sea surface height (SSH) data provided by along-track nadir altimeters.  The space-time distribution of observed data limits the resolution of the maps to approximately 150 km and 20 days in wavelength. The launch of the next-generation SWOT altimetry mission in 2021 opens the way to high resolution maps thanks to an unprecedented kilometric resolution over a swath wide of 120 km. However, new advanced mapping techniques that involve information on ocean dynamics should be explored to take advantage of the high spatial resolution of SWOT. In this study, a data assimilation algorithm, the back and forth nudging (BFN), is implemented with a one and half layer quasi geostrophic model (QG) to dynamically interpolate the altimetric data.  We test the QG/BFN system to dynamically map SSH with synthetic but realistically distributed altimetric observations in the framework of Observing System Simulation Experiments (OSSE). The study focuses on two regions of the North-Atlantic ocean, presenting different dynamics and characterized by different temporal samplings of SWOT.

A systematic comparison with the traditional objective mapping technique demonstrates that the QG/BFN brings a significant improvement of the quality of the maps using only conventional nadir altimeter data. This outperformance of the QG/BFN is further increased when SWOT is added in the altimetric dataset. Our method is particularly effective for reconstructing non-linear surface dynamics at small mesoscales (40-100 km) that are smoothed out by conventional methods based on optimal mapping.
Spatial Distribution of the Hydrothermal Black Matrix Breccia and its Impact on the Irish-type Zn-Pb Mineralisation
Authors: Vafeas Nicholas , Hitzman Murray , Johnson Sean , Güven John
Published: March 2020

The Mississippian Waulsortian Formation of the Irish Midlands hosts a number of significant Zn-Pb mines including Lisheen, Galmoy and Silvermines. Consisting predominantly of sphalerite, galena and pyrite, the deposits are intimately associated with hydrothermal dolomite and dolomitic breccias, commonly referred to as “Black Matrix Breccia” (BMB). The hydrothermal dolomite and associated breccias form a predominantly tabular body that largely envelops the zone of sulphide mineralisation. A wide variety of mineralisation styles and textures are recognized, however the majority of the mineralisation resulted through replacement of this hydrothermal dolomite. Recent geochemical evidence indicates that the hydrothermal dolomite contains distinct geochemical signatures that may be useful in sulphide exploration within the Irish Midlands. To date, little work has been conducted on the spatial distribution and variability of this significant hydrothermal dolomite and the role it plays in ore genesis within the Irish Midlands. Through detailed petrographic characterisation, this study documents the distribution of the hydrothermal dolomite. This distribution helps constrain the origin of the massive Zn-Pb deposits and forms an important tool for future mineral exploration in the Irish Orefield.
Model-based hydrodynamic leveling; a power full tool to enhance the quality of the geodetic networks
Authors: Afrasteh Yosra , Slobbe Cornelis , Verlaan Martin , Sacher Martina , Klees Roland
Published: March 2020

Model-based hydrodynamic leveling is an efficient and flexible alternative method to connect islands and offshore tide gauges with the height system on land. The method uses a regional, high-resolution hydrodynamic model that provides total water levels. From the model, we obtain the differences in mean water level (MWL) between tide gauges at the mainland and at the islands or offshore platforms, respectively. Adding them to the MWL relative to the national height system at the mainland’s tide gauges realizes a connection of the island and offshore platforms with the height system on the mainland. Usually, the geodetic leveling networks are based on spirit leveling. So, as we can not make the direct connections between coastal countries, due to the inability of the spirit leveling method to cross the water bodies, they are weak in these regions. In this study, we assessed the impact of using model-based hydrodynamic leveling connections among the North Sea countries on the quality at which the European Vertical Reference System can be realized. In doing so, we combined the model-based hydrodynamic leveling data with synthetic geopotential differences among the height markers of the Unified European Leveling Network (UELN) used to realize the European Vertical Reference Frame 2019. The uncertainties of the latter data set were provided by the BKG. The impact is assessed in terms of both precision and reliability. We will show that adding model-based hydrodynamic leveling connections lowers the standard deviations of the estimated heights in the North Sea countries significantly. In terms of reliability, no significant improvements are observed.
Emergence of heat stress hazards in the CMIP6 models
Authors: Lord Natalie S. , Mitchell Dann M.
Published: March 2020

Hazards associated with the combined effects of temperature and humidity can have a wide range of impacts, particularly on human health and agriculture. The human body removes metabolic heat through sweating and heat conduction, and the efficiency of these processes is reduced when ambient temperatures and humidity are high, resulting in heat stress. The effects of this range from general discomfort to increased morbidity and mortality rates, trends that have been observed during recent severe heatwaves such as those that occurred during the summer of 2019 in Europe. A number of factors may exacerbate heat stress, including intense physical activity and being located in an urban area as opposed to a rural area.

As global temperatures increase, the risk associated with heat stress hazards is expected to increase, and this signal is expected to emerge from natural variability over the coming decades, if not sooner. Here, simulations from the new CMIP6 models are analysed to investigate the timing of emergence of heat stress hazards, in order to identify regions of the globe that are particularly vulnerable to extreme heat stress and/or imminent emergence of these hazards. Event attribution techniques are also applied to estimate the impact of anthropogenic warming on the hazard risk.
Plio-Pleistocene glacial history of the Melville Bugt Ice Stream
Authors: Newton Andrew , Cox David , Huuse Mads , Knutz Paul
Published: March 2020

In this work we use high-resolution seismic reflection surveys collected across the northeast Baffin Bay region to investigate the glacigenic Melville Bugt Trough Mouth Fan (MB-TMF). The MB-TMF stratigraphy is characterised by over 100 km of progradation since ~2.7 Ma and the heterogeneous truncation or subsidence of topset strata. Variation in topset character is thought to relate to the waxing and waning of the northwest sector of the Greenland Ice Sheet across the shelf since ~2.7 Ma. 3D seismic reflection data reveal the preservation of multiple sets of mega-scale glacial lineations, suggesting that grounded ice extended across the shelf a number of times since the onset of the Middle Pleistocene Transition. Seismic geomorphology and facies analysis of the prograding clinoforms show repeated observations of debrites and gully systems. These features, when considered with other evidence of adjacent glacial landforms and strata, are taken to infer gravity-driven processes and the presence of meltwater-related hyperpycnal flows in areas proximal to the ice sheet on the outer shelf. Bottomset contourites at the base of the continental slope also provide insights into the evolution of the West Greenland Current in Baffin Bay through the Pleistocene, with deposition estimated to have started in the latest Calabrian, based on the current age model. Regional stratigraphic mapping shows that the MB-TMF can be summarised into four stages that were primarily controlled by variations in ice sheet erosion patterns, topographic forcing of ice flow, and changes in accommodation that are related to glacigenic deposition and tectonic subsidence. 
Are models becoming more sensitive to Pliocene boundary conditions?
Authors: Haywood Alan , Tindall Julia
Published: March 2020

The nature and dynamics of Pliocene climate has been a focus of intense study for many years. This is because the Pliocene has a unique potential to inform science/society about how the Earth system responds to forcing of direct relevance to future climate change. We examine large-scale climate features derived from the second phase of the Pliocene Model Intercomparison Project. PlioMIP2 is composed of simulations derived from sixteen coupled atmosphere-ocean and Earth System Models of a variety of vintages (IPCC AR3/4 to 6). This represents one of the largest ensembles of models ever assembled to represent a particular interval in Earth history. Each model has been set up to include the very latest Pliocene boundary conditions provided by the U.S. Geological Survey Pliocene Research Interpretation and Synoptic Mapping Project (PRISM4). As well as examining large-scale features of the PlioMIP2 model ensemble we further examine trends in model sensitivity versus model age in order to ascertain if newer versions of models are becoming more sensitive to Pliocene boundary conditions. We examine this across the PlioMIP2 ensemble as a whole and within individual model families, and examine what this implies in terms of the potential for individual models, or families of models, to represent patterns of surface temperature change reconstructed from geological proxies.
Study of mountain-wave-induced stratospheric cooling over the Antarctic Peninsula using a parameterisation scheme in the UM-UKCA chemistry climate model
Authors: Orr Andrew , Hosking Scott , Delon Aymeric , Moffat-Griffin Tracy , Hoffman Lars , Spang Reinhold , Abrahams Luke , Keeble James , Braesicke Peter
Published: March 2020

An important source of polar stratospheric clouds (PSCs), which play a crucial role in controlling polar stratospheric ozone depletion, is from the temperature fluctuations induced by mountain waves, enabling stratospheric temperatures to fall below the threshold value for PSC formation in the cold phases of these waves even if the synoptic-scale temperatures are too high. However, this formation mechanism is usually missing in chemistry–climate models because these temperature fluctuations are neither resolved nor parameterised. Here, we investigate the representation of parameterised stratospheric mountain-wave-induced temperature fluctuations over the Antarctic Peninsula from a 30-year run of the global chemistry-climate configuration of the UM-UKCA model against climatologies of Atmospheric Infrared Sounder (AIRS) radiance measurements and high-resolution radiosonde temperature soundings from Rothera. The results demonstrate that the local mountain wave-induced cooling phases computed by the scheme are in relatively good agreement with both sets of observations. For example, the scheme is able to capture the observed probability distribution of the temperature fluctuations, particularly the cold tails of the distribution that are critical for exceeding the temperature threshold for PSC formation. Further analysis shows that the increased stratospheric cooling induced by the scheme results in a large increase in total PSC ‘pseudo-volume’ of the area over the Antarctic Peninsula where the model temperature exceeds the temperature threshold of formation of PSCs.
Modelling the Antarctic Ice Sheet in the warm Mid-Pliocene
Authors: O'Neill James , Edwards Tamsin , Gregoire Lauren , Gandy Niall , Dolan Aisling , Wernecke Andreas , Cornford Stephen , de Boer Bas , Kelman Ilan , van de Flierdt Tina
Published: March 2020

The Antarctic ice sheet is a deeply uncertain component of future sea level under anthropogenic climate change. To shed light on the ice sheets response to warmer climates in the past and its’ response to future warming, periods in Earth’s geological record can serve as instructive modelling targets. The mid-Pliocene warm period (3.3 – 3.0 Ma) is characterised by global mean surface temperatures ~2.7-4oC above pre-industrial, atmospheric CO2 concentrations of ~400ppm and eustatic sea level rise on the order of ~10-30m above modern. The mid-Pliocene sea level record is subject to large uncertainties. The upper end of this record implies a significant contribution from Antarctica and possible collapse of regions of the ice sheet, driven by marine ice sheet instabilities.

We present a suite of BISICLES ice sheet model simulations, forced with a subset of Pliocene Modelling Intercomparison Project (PlioMIP phase 1) coupled atmosphere-ocean climate models, that represent the Pliocene Antarctic ice sheet. This ensemble captures a range of possible ice sheet model responses to a warm Pliocene-like climate under different parameter choices, sampled in a Latin hypercube design. Modelled Antarctic sea level contribution is compared to reconstructions of Pliocene sea level, to explore the extent to which available data with large uncertainties can constrain the model parameter values.

Our aim with this work is to provide insights on Antarctic contribution to sea level in the warm mid-Pliocene. We seek to characterise the role of ice-ocean, ice-atmosphere and ice-bedrock parameter uncertainty in BISICLES on the ice sheet sea level contribution range, and whether cliff instability processes are necessary in reproduce high Pliocene sea levels in this ice sheet model.
Performance assessment of data reconstruction and correction in meteorological timeseries
Authors: Bavay Mathias , Fiddes Joel , Aschauer Johannes
Published: March 2020

Models that consume meteorological data have often requirements that are quite incompatible with the realities of continuously measured data: they require gapless data when datasets have gaps, they require sampling rate matching the phenomena of interest when datasets use a sampling rate dictated by energy and storage capacities, they require ‘perfect’ data when sensors have flaws.

 

The MeteoIO library [1] has been designed to solve this discrepancy as a meteorological data pre-processing library for numerical models (as well as other applications consuming such data), able to read measured data from a variety of sources and to standardize it into a unique representation (parameters naming and units) as well as filter, correct, resample and spatially interpolate it according to the end user’s configuration. From its very beginning, it aimed to be a toolbox that allows the user to choose from a large panel of published methods for each of the processing steps

 

Unfortunately, until now there has been no systematic assessment of the performance of the available methods nor recommendations on best strategies. Based on an extensive network of Automatic Weather Stations (AWS) located around Davos, Switzerland, we present our preliminary recommendations for data reconstruction and corrections. Artificially degraded data allow us to compare the reconstruction with the original data, either exclusively based on the local data or by using neighboring stations. The high quality instruments available at Davos Weissfluhjoch (2536m a.s.l.) similarly allow us to compare various correction methods applied to the simpler kind of sensors normally found on regular AWS.

 

 

[1] Bavay, M. and Egger, T., "MeteoIO 2.4.2: a preprocessing library for meteorological data", Geosci. Model Dev., 7, 3135-3151, doi:10.5194/gmd-7-3135-2014, 2014.
Applying the climatic water balance to the Volta basin as an accounting framework to aid policy makers in understanding climate pressures on the water-energy-food (W-E-F) nexus
Authors: Forsythe Nathan , Pritchard David , Fowler Hayley
Published: March 2020

The multinational FutureDAMS consortium -- funded by the UK's Global Challenges Research Fund -- is working to improve the design, selection and operation of dams to support sustainable development. Existing and planned large water storage infrastructure systems have the potential to make a significant contribution towards achieving the Sustainable Development Goals and Paris climate change commitments. But maximising the benefits while minimising the negative social and environmental impacts of large-scale infrastructure in the river basins comprising the multifunctional cores of the Water-Energy-Food (WEF) nexus remains a challenge. One critical aspect of this challenge is the difficulty of achieving uptake of scientific guidance by policy makers and other influential stakeholders.

The climatic water balance (CWB), i.e. precipitation minus potential evapotranspiration, provides a methodological framework for understanding moisture supply-demand equilibrium at a range of spatial scales including those relevant to land management – administrative districts and tributary watersheds – within basins. The CWB framework understood as an accounting analogy – i.e. rainfall as income, evapotranspiration as expenditure – can be comprehensible to scientific lay persons and help to understand the climate pressures which constrain WEF resource management. Viewed through a CWB framework, rural lands are critical both as determinants of rainfall partitioning between runoff and infiltration as well as areas of consumptive water usage for food production. Runoff entering engineered river systems becomes available for satisfying water supply and (hydropower) energy demands. As a transboundary river basin in a region experiencing substantial demographic growth and with strong aspirations for rapid economic development, inter-sectoral tensions are likely as Volta basin decision makers and economic actors seek to satisfy elements of the W-E-F nexus. By quantifying spatiotemporal moisture supply-demand balance conditions the CWB can provide valuable information to quantify trade-offs and potential synergies resulting from land management practices, infrastructure development and water allocation policies.

In this work we will examine point/site-based values and spatial aggregates of CWB for a range of locations and scales within the larger Volta basin. For each case we will identify key WEF issues which are influenced by the CWB as well as stakeholders whose decision-making processes could be informed by insights derived from the CWB (accounting) framework.
Receiver function analyses and joint inversion with gravity data: new constraints on the Ivrea geophysical body along a high-resolution profile
Authors: Scarponi Matteo , Hetényi György , Plomerová Jaroslava , Solarino Stefano , Baron Ludovic
Published: March 2020

We collected new seismological and gravity data in the Val Sesia and Lago Maggiore regions in NW Italy to constrain the geometry and properties of the Ivrea Geophysical Body. This piece of lower Adriatic lithosphere is known to be at anomalously shallow depth along the inner arc of the Western Alps, yet existing seismological constraints (vintage seismic refraction data, local earthquake tomography) are spatially sparse. With the aim to reach higher spatial resolution in imaging the structure of the IGB, we analyze the seismological data with various receiver function approaches to map the main velocity discontinuities, followed by joint inversion with gravity data to fill the bulk properties of bodies with densities.

The new data acquisition consisted of two type of campaigns. For seismology, we deployed 10 broadband seismic stations (MOBNET pool, IG CAS Prague) along a linear West-East profile at 5 km spacing along Val Sesia and across the Lago Maggiore. This network continuously recorded seismic data for 27 months at 100 Hz sampling rate. For gravimetry, we compiled existing datasets and then completed the spatial gaps by relative gravity surveys, tied to absolute reference points, to achieve 1 gravity point every 1-2 km along the profile.

The receiver function (RF) analyses aim at detecting velocity increases with depth: primarily the Moho and the shallow IGB interfaces and their crustal reverberations (multiples), together with their potential dip by analyzing the transverse component RFs. Furthermore, we aim at investigating the sharpness of the velocity gradient across the discontinuities by analyzing the frequency dependence of the corresponding RF peaks. We aim at reproducing the observations by simple synthetic models.

The 2D joint inversion combines S wave velocity VS and bulk density as physical parameters to match both the seismological and gravimetry data. The relationship between the two parameters is initially chosen from the literature, but depending on the first results the relation itself may be inverted for, considering the various high-grade metamorphic rocks observed at the surface in the area, whose properties may not align with classical VS–density equations. In conclusion, we propose new constraints on the IGB, demonstrating the advantage of using multi-disciplinary geophysical observations and improved data coverage across the study area.
Relationships linking satellite-retrieved ocean color data with atmospheric components in the Arctic
Authors: Marbouti Marjan , Jang Sehyun , Becagli Silvia , Nieminen Tuomo , Navarro Gabriel , Kerminen Veli-Matti , Sipilä Mikko , Kulmala Markku
Published: March 2020

We examined the relationships linking in-situ measurements of gas-phase methanesulfonic acid (MSA), sulfuric acid (SA), iodic acid (HIO3), Highly Oxidized Organic Molecules (HOM) and aerosol size-distributions with satellite-derived chlorophyll (Chl-a) and oceanic primary production (PP). Atmospheric data were collected at Ny-Ålesund site during spring-summer 2017 (30th March-4th August). We compared ocean color data from Barents Sea and Greenland Sea with concentrations of low-volatile vapours and new particle formation. The aim is to understand the main factors controlling the concentrations of atmospheric components in the Arctic in different ocean domains and seasons. Early phytoplanktonic bloom starting in April at the marginal ice zone caused Chl-a and PP in the Barents Sea to be higher than in the Greenland Sea during spring, whereas the pattern was opposite in summer. We found the correlation between ocean color data (Chl-a and PP) and MSA decreasing from spring to summer in Barents Sea and increasing in Greenland Sea. This establishes relationship between sea ice melting and phytoplanktonic bloom, which starts by sea ice melting. Similar pattern was observed for SA. Also HIO3 in both ocean domains correlated with Chl-a and PP during spring time. Greenland Sea was more active than Barents Sea. These results suggest that marine phytoplankton metabolism is an important source of MSA and SA, as expected, but also a source of HIO3 precursors (such as I2). HOMs had low correlation with ocean color parameters in comparison to other atmospheric vapours in this study both in spring and summer. The plausible explanation for low correlation is that the primary source of Volatile Organic Compounds (VOC) – precursors of HOM – is the soil of Svalbard archipelago rather than ocean. During spring, nucleation mode particles were found to correlate with Chl-a at Barents Sea and with PP at Greenland Sea. This means that biogenic productivity has a strong impact on new particle formation in spring although small particles are not related to biogenic parameters in summer.
Using subsidence scenarios to assess flood risk to delta cities under future sea level rise.
Authors: Jackson Luke
Published: March 2020

City level coastal subsidence can be caused by a number of factors, both natural (e.g. compaction) and anthropogenic (e.g. ground water extraction). Past observations in cities indicates that the rate of subsidence can be altered through policy intervention (e.g. Tokyo's ban on ground water pumping in 1970's). Given vertical land motion is a key component in local sea level projections where subsidence amplifies the onset of future damages, we test the extent to which intervention could reduce risk with a simple city level coastal damage model. We adjust water levels to embed different time dependent subsidence scenarios over the 21st century. We contend that local policy intervention to slow anthropogenic subsidence where possible will slow the onset of damaging sea level rise thus reducing potential coastal damages, and reduce the required increases in future flood protection heights. Performed in tandem with global mitigation efforts, cities currently under major threat may yet survive the climate crisis.
An inductive approach to characterize physical, chemical, and biological system interactions in a 5th order river basin
Authors: Ward Adam , Drummond Jennifer , Li Angang , Lupon Anna , Kurz Marie , Zarnetske Jay , Stegen James , Marti Eugenia , Ouellet Valerie , Brekenfeld Nicolai , Mao Feng , Graham Emily , Bernal Susana , Krause Stefan , Hannah David
Published: March 2020

Research in the river corridor commonly focuses in two study designs. One research strategy focuses on physical, chemical, and/or biological dynamics and feedbacks, emphasizing local variation and interaction over larger-scale context. A second study design focuses on gradients arising in response to non-local controls (e.g., climate, tectonic setting), with an emphasis on broad trends over smaller-scale “noise”. Here, we present a comprehensive set of measurements and calculated metrics describing physical, chemical, and biological conditions collected at 62 sites in the river corridor within a 5th order basin including more than 150 variables at each site. The size and scope of this data set allows us to assess which variables have spatial structure in the basin using spatial semivariograms and regressions with discharge and drainage area. We ask how physical, chemical, and biological sub-systems co-vary using a principal components analyses. Next, we explain both spatial structure and local variance simultaneously using support vector machine regression techniques that reveal possible nonlinear, multivariate relationships that may direct future research. Key outcomes from this study include (1) an introduction to an open-source, comprehensive characterization of the river corridor, (2) interpretations of both broad trends and local variance in the river corridor, and (3) a summary of which metrics have the most explanatory power and why within the study system.
Earth Observation for Accurate Mapping of Soil Functional Properties, Land Health and Soil Infiltrability in Rwanda
Authors: Vågen Tor-Gunnar , Winowiecki Leigh Ann , Bargues-Tobella Aida
Published: March 2020

Earth observation (EO) has a large potential for mapping of soil functional properties such as soil organic carbon, soil pH or acidity, soil fertility parameters and soil texture. Recent advances in the application of EO data in combination with systematic field data sampling, standardized soil data reference analysis and the use of soil spectroscopy have shown these approaches to be both robust and scalable. We present a case study from Rwanda where we apply EO data in combination with field and laboratory data collected using the Land Degradation Surveillance Framework (LDSF) to map functional soil properties, soil erosion prevalence and land cover at fine spatial resolution. Digital soil maps were produced at a spatial resolution of 30m with an accuracy of 85 to 90%, while soil erosion prevalence was mapped with an accuracy of 86% using Landsat satellite imagery and machine learning models. 

We also assess interactions between spatial assessments of soil organic carbon, soil erosion prevalence and land cover at a spatial resolution of 30m in order to identify land degradation hotspots and better target interventions to restore degraded land across four districts in Rwanda. We further explore the effects of soil erosion, root-depth restrictions and soil organic carbon content on saturated hydraulic conductivity in three LDSF sites in Nyagatare, Kayonza and Bugesera districts, respectively. Saturated hydraulic conductivity was modeled based on single-ring measurements of infiltration capacity using a modified Reynolds & Elrick steady-state single ring model for 48 LDSF plots per site. The results show significant spatial variation in infiltrability within sites.

The results of the study show the importance of rigorous protocols for sampling and analyses of soil properties and indicators of land health across landscapes. By simultaneously assessing soil properties, indicators of land degradation and soil infiltrability we demonstrate the utility of these approaches in understanding drivers of land degradation across multiple spatial scales for targeting of options for land restoration and monitoring of the effectiveness of these interventions over time across multiple dimensions of land health.
Dynamics of the 1989 fracture system and relations with the Etna eruptive activity of the last 30 years
Authors: Gambino Salvatore , Aiesi Giampiero , Bonforte Alessandro , Brandi Giuseppe , Calvagna Francesco , Consoli Salvatore , Distefano Giovanni , Falzone Giuseppe , Ferro Angelo , Guglielmino Francesco , Laudani Giuseppe , Marsala Giuseppe , Obrizzo Franco , Privitera Laura , Puglisi Giuseppe , Russo Salvatore , Saraceno Benedetto , Velardita Rosanna
Published: March 2020

On September 11, 1989, after four months of Strombolian activity at the summit craters, effusive activity began on Mt. Etna and lasted about a month.

The 1989 eruption of Mt. Etna was characterized by the formation of two fracture systems, striking NE-SW and NNW-SSE, and both starting from the SE Crater on September, 24.

The NE-SW system was followed by effusive activity while the NNW-SSE fractures opened for a length of 7 km without eruptive phenomena. Between September, 27 and October, 3 the fracture system propagated until it reached and cut the SP 92 provincial road (Zafferana - Rifugio Sapienza), near the 1792 effusive mouth, and continued southward for another 700 m.

We investigated the fracture southern branch dynamics through 30 years of ground deformation data collected by the discrete and continuous INGV monitoring networks. We considered levelling, GPS, EDM, and extensometers data. EDM and levelling measurements began in the 80s; on 2003 EDM measurements have been replaced by GPS.

During the 1989 eruption, EDM measurements showed variations of tens of centimeters on the lines close to the fracture.

Precise levelling discrete measurements revealed, in the period 4-16 October 1989 and during the 1991-1993 eruption a subsidence of some centimeters on benchmarks close to fracture.

A network of rod extensometers evidenced the fracture activation during the 2001 intrusion phases (12-17 July) measuring several centimeters of left lateral slip. Distance measurements and InSAR show signs of the fracture reactivation during the 2002 and 2018 eruptions.

Several authors show as the 1989 fracture zone connects the summit region of the volcano with the tectonic structures of the lower SE flank considering it as well part of the NNW-SSE oriented structure.

The dynamics of these last 30 years suggests that the 1989 fracture play an important role on the flank dynamics and strain distribution. It also represents a potential hazard to population because it represents a possible way of ascending magma also testified by cones aligned along the structure.