bluuebunny/crossref_metadata_2025 huggingface dataset:
Geostatistical Modeling of Carbon Monoxide Levels in Khartoum State-GIS Based Study
Authors: Alhuseen Ahmed
Published: March 2020

The main objective of this research work is to demonstrate the potential of using Geographic Information System (GIS) in exposure, risk assessment and emission predictions for Khartoum state. One of the objectives of this study is to develop a digital GIS model; that can evaluate, predict and visualize Carbon Monoxide (CO) levels in Khartoum state. To achieve these aims, sample data had been collected, processed and managed to generate a dynamic GIS model of Carbon Monoxide levels in the study area.

  GIS and geostatistical models were found to be valuable tools for creating interactive and dynamic models to enhance the visualization and analysis of Carbon Monoxide emissions in Khartoum state. Parametric data collected from the field and analysis carried throughout this study show that (CO) emissions were much lower than the allowable ambient air quality standards released by National Environment Protection Council (NEPC) for 1998. However, this pilot study has found emissions of (CO) to be unevenly distributed geographically as well as temporally; with Omdurman city exhibiting highest (CO) levels. This pilot study shows that GIS and geostatistical modeling can be used as a powerful tool to produce maps of exposure to enhance exposure assessment in environmental studies.               
Statistical characterization of the sea-breeze physical mechanisms through in-situ and satellite observations
Authors: Grau Ferrer Antoni , Jiménez Cortés Maria Antònia , Cuxart Rodamilans Joan
Published: March 2020

The physical mechanisms that take place under sea-breeze (SB) conditions in the Palma basin (Mallorca island, western Mediterranean sea) are analyzed through the inspection of data from automatic weather stations (AWS) during the period 2009-2017. Satellite-derived land-surface and sea-surface temperatures (LST and SST, respectively) are used to compute the surface thermal gradient (LST-SST) in the Palma basin. It presents a clear daily and seasonal cycles, and the daytime hourly averages for each month are always positive and maximal during summer time.

 

A method similar to the one proposed by Borne et al. (1998) is used to select the SB events from AWS data in Palma basin. Although the thresholds are valid for the SB features in the Palma basin, the method can be applied to other regions. SB conditions are mainly reported during the warm months of the year (from April to September) and specially during summer time. Results from the statistical analysis show that the SB follows diurnal cycle already described in previous works. Among the characteristics founded, the morning veering strongly depends on the speed and direction of the large-scale winds. Besides, weak wind conditions are reported during the morning veering and once the SB starts the cold advection from the sea counteracts the radiative heating and the 2 m-temperature levels off. The maximum surface thermal gradient under SB conditions is larger than 5ºC and it is often reported several hours after the morning veering. About two hours later the maximum wind speed is formed, strongly influenced by the amount of soil moisture. The thermal winds formed inside the basin also condition the propagation of the SB inland. The statistical analysis shows that the SB features in Mallorca depart from the idealized conditions due to the complex terrain of the island.
Trends and interconnections of physical parameters in the upper layer of the Mediterranean Sea
Authors: Menna Milena , Notarstefano Giulio , Mauri Elena , Gačić Miroslav , Civitarese Giuseppe , Gerin Riccardo , Poulain Pierre-Marie
Published: March 2020

The Mediterranean Sea is considered a hot spot of the global warming since it is changing faster than the global ocean, with a strong impact on the marine environment. Recent studies agree on the increase of the sea level, of the Sea Surface Temperature (SST), and of the Sea Surface Salinity (SSS) in the Mediterranean Sea over the last two decade, but no one has yet come to interconnect these and other parameters that contribute to the regulatory effect of the sea on the climate.

In this study, interannual variability and decadal climatic trends in the upper-layer of the Mediterranean Sea are estimated in the last 26 years using in-situ data (Argo float), satellite (altimetry, SST, wind vorticity, freshwater fluxes, mixed layer depth) and model (SSS) products.

Spatio-temporal variability is studied performing the Empirical Orthogonal Function analysis on the gridded, monthly, de-seasonalized maps of all satellite and model data. The contribution of the western, central and eastern regions of the Mediterranean Sea to the total trends is assessed. SSS distribution and trends derived from model reanalysis are compared with those derived from Argo float data in the upper layer.

Possible relationships between the trends in different datasets are delineated and described, i.e. the connection between the sea level rise and the SST, between the freshwater fluxes and the SSS, between the SSS and the ocean dynamics, including Ekman and geostrophic transports as well as vertical entrainment.
Examples of DAFNE application to multi-temporal and multi-frequency remote sensed images and geomorphic data for accurate flood mapping.
Authors: D'Addabbo Annarita , Refice Alberto , Lovergine Francesco , Pasquariello Guido
Published: March 2020

DAFNE(Data Fusion by Bayesian Network) is a Matlab-based open source toolbox, conceived to produce flood maps from remotely sensed and other ancillary information, through a data fusion approach [1]. It is based on Bayesian Networks and it is composed of five modules, which can be easily modified or upgraded to meet different user needs. DAFNE provides, as output products, probabilistic flood maps, i.e., for each pixel in a given output map, the probability value that the corresponding area has been reached from the inundation is reported. Moreover, if remote sensed images have been acquired in different days during a flood event, DAFNE allows to follow the inundation temporal evolution.

It is well known that flood scenarios are typical examples of complex situations in which different factors have to be considered to provide accurate and robust interpretation of the situation on the ground [2]. In particular, the combined analysis of multi-temporal and multi-frequency SAR intensity and coherence trends, together with optical data and other ancillary information, can be particularly useful to map flooded area, characterized by different land cover and land use [3]. Here a recent upgrade is presented that allows to consider as input data multi-frequency SAR intensity images, such as X-band, C-band and L-band images.

Three different inundation events have been considered as applicative examples: for each one, multi-temporal probabilistic flood maps have been produced by combining multi-temporal and multi-frequency SAR intensity images images (such as COSMO-SkyMed , Sentinel-1 images and ALOS 2 images), InSAR coherence and optical data (such as Landsat 5 images or High Resolution images), together with geomorphic and other ground information. Experimental results show good capabilities of producing accurate flood maps with computational times compatible with a near real time application.

 

[1] A. D’Addabbo, A. Refice, F. Lovergine, G. Pasquariello, DAFNE: A Matlab toolbox for Bayesian multi-source remote sensing and ancillary data fusion, with application to flood mapping. Computer and Geoscience 112 (2018), 64-75.

[2] A. Refice et al, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, vol. 7, no. 7, pp. 2711–2722, 2014.

[3] A. D’Addabbo et al., “A Bayesian Network for Flood Detection combining SAR Imagery and Ancillary Data,” IEEE Transactions on Geoscience and Remote Sensing, vol.54, n.6, pp.3612-3625, 2016.

 
Spectral and spatial interpolation of precipitation for daily and hourly time series
Authors: Mehrvand Masoud , Bárdossy András
Published: March 2020

Generating synthetic precipitation for weather generators were always a challenging issue in hydro-climate simulations because of its high variability in time and space. We present a spectral method for generating the synthetic precipitation time series which is in accordance with the observed precipitation statistical characteristics not only for the observed points, but also for any desired location by interpolating the time series spectrum. In this regard, time series spectra derived from the observed signal converting from its time domain to the corresponding frequency domain using the Fourier transform.

The main problem for spectral interpolation of precipitation time series is highly occurrence of non-rainy days which can be even more inaccurate for the finer resolutions such as hourly and sub-hourly data. In order to overcome the highly frequent occurrence of non-rainy days, transformation between indicator and normal correlation has been taken into account.

This method enables us to generate synthetic time series with same statistical characteristics for the observed points and also for any point of interests rather than the observed points. The introduced so called spectral and spatial interpolation method applied for daily and hourly precipitation time series for the selected stations in state Baden-Württemberg, Germany.
Displacement-length scaling relationships for a fault array reveal that faults grow via alternating phases of lengthening and localisation
Authors: Pan Sophie , Bell Rebecca , Jackson Christopher
Published: March 2020

Rifting of the continental lithosphere is accommodated by the development of large, linked, normal fault arrays. However, the timescales over which fault arrays develop - from the interaction of small, isolated faults towards localisation of through-going fault systems, has not been well constrained from observations in natural systems. Our limited knowledge of timescales over which fault arrays develop has also resulted in the development of different and debated fault growth models. While scaling relationships between fault displacement and length have been extensively used to understand fault evolution, the scaling exponent value is still not resolved due to significant scatter in global displacement-length profiles.

Here we use 3D seismic reflection and borehole data from the Exmouth Plateau, NW Shelf of Australia to investigate the timescales of faults growth within an array. The excellent quality seismic data allows for the entire Jurassic to Early Cretaceous fault array to be analysed over a large areal extent (~1200 km2), and the fault activity can be dated using biostratigraphy from wells. Our study is novel in that we reconstruct and quantify the length and throw on faults back through time to investigate how fault populations evolve. We find that the early stage of rifting was characterised by distributed faulting, where fault trace lengths were established early within the first 7.2 Myrs of rifting (out of a total rifting duration of 85.5 Myrs). By 28.5 Myrs of rifting (33% of the total rifting duration), strain localises on major west dipping faults as a fully linked system. Localisation continues on major faults until the cessation of rifting where strain is accommodated with maximum throw in the centre of faults decreasing towards its tips. Our results suggest that fault displacement and length may scale linearly, but grow in alternations of fault lengthening and fault displacement phases. The growth of active fault systems and death of inactive faults located in stress shadow zones is responsible for the scatter of data points frequently observed in global displacement-length profiles.
Estimating the Above Ground Biomass of Brazilian Savanna using multi-sensor approach
Authors: da Conceição Bispo Polyanna , Rodriguez-Veiga Pedro , Zimbres Barbara , do Couto de Miranda Sabrina , Henrique Giusti Cezare Cassio , Fleming Sam , Baldacchino Francesca , Zanin Shimbo Julia , Auxiliadora Costa Alencar Ane , Roitman Iris , Bustamante Mercedes , Pacheco-Pascagaza Ana Maria , Gou Yaqing , Roberts John , Louis Valentin , Barret Kirsten , Woodhouse Iain , Sousa-Neto Eráclito , P.H.B. Ometto Jean , Balzter Heiko
Published: March 2020

The Brazilian Savanna, known as Cerrado (Cerrado sensu lato (s.l.)), is the second largest biome in South America. It comprises different physiognomies due to variations of soil, topography and human impacts. The gradients of tree density, tree height, above ground biomass (AGB) and wood species cover vary according to the Cerrado formation, ranging from different grassland formations (Campo limpo, campo sujo), savanna intermediary formations (Campo cerrado and Cerrado sensu stricto - s.s) and forest formations (Cerradão, Mata ciliar, Mata de galeria and Mata Seca).

Although the carbon stock in Cerrado is lower than in the Brazilian Amazon, the conversion of this biome to other types of land use is occurring much faster. In the last ten years, the degradation of Cerrado forest was the second largest source of carbon emissions in Brazil. Therefore, effective methods for assessing and monitoring aboveground woody biomass and carbon stocks are needed. A multi-sensor Earth observation approach and machine learning techniques have shown potential for the large-scale characterization of Cerrado forest structure.The aim of this study is to present a method to estimate the AGB of an area of the Brazilian Cerrado using ALOS-PALSAR (L-band SAR), Landsat, LIDAR (LIght Detection And Ranging) and field datasets. Field data consisted of 15 plots of 1 ha area located in Rio Vermelho watershed in Goiás-State (Brazil). We used a 2-step AGB estimation (i) from the field AGB using LIDAR metrics and (ii) from LIDAR-AGB to satellite Earth Observation scales following a Random Forest regression algorithm.  The methodology to estimate ABG of Cerrado Stricto Sensu vegetation is part of the Forests 2020 project which is the largest investment by the UK Space Agency, as part of the International Partnerships Programme (IPP), to support in the improvement of the forest monitoring in six partner countries through advanced uses of satellite data.
Lithological and erosional controls on orogen width in the Bolivian Andes
Authors: Whipp David , Kaislaniemi Lars
Published: March 2020

Orogen fold-and-thrust belts (FTBs) often have a tapering wedge geometry in cross section, which develops as a result of the balance between stresses acting along the detachment fault beneath the wedge, its internal strength, and the average slope of the surface topography from the back of the wedge to its toe. The geometry of these critical wedges is thus sensitive to changes in factors that influence stress along the wedge base or the surface slope, including changes in the mechanical strength of the detachment fault or variations in surface erosional efficiency. The Andes of eastern Bolivia have differences in the basal detachment strength, resulting from a thinning of the weak Paleozoic sediments that host the basal detachment, and average annual rainfall north and south of the bend in the orogen at ~18°S. In addition, the orogen and active Subandean FTB are ~50% narrower in the north, where both the detachment layer strength may be higher and the average annual rainfall is around eight times that in the south. This raises the question: What controls orogen width in the Bolivian Andes?

We explore the effects of variations in the mechanical strength of the basal detachment and surface erosional efficiency on FTB width using 3D numerical geodynamic models with lateral variations in these parameters along strike. Our numerical experiments calculate the orogen geometry using the DOUAR geodynamic modelling software (Braun et al., 2008) coupled to the FastScape surface process model (Braun and Willett, 2013). The model design includes an elevated plateau region that is thrust over a weak frictional plastic detachment layer, resulting in growth of an orogenic wedge at the distal plateau margin. The plateau geometry is also bent, including a 40° change in margin orientation along strike; changes in the erosional efficiency and detachment strength are varied on either side of this bend. We find that changes in detachment strength result in significant differences in FTB width, while changes in erosional efficiency have little effect. Increasing the detachment strength by two results in limited forward propagation of the thrust front and a reduction in the FTB width by roughly 50% compared to the weaker side of the model. In contrast, increasing precipitation by a factor of three (as a proxy for enhanced erosional efficiency) does not significantly effect the FTB width. These results compare well with the observed variations in orogen width in the Bolivian Andes, suggesting the FTB width may be controlled by the detachment strength, while variations in erosional efficiency have a limited effect. Ongoing work is exploring how changes in detachment strength and erosional efficiency may affect thermochronometer ages predicted from the numerical experiments, and how the predicted ages compare to ages observed in the Bolivian Andes.
Characteristics of a HSS-driven magnetic storm in the high-latitude ionosphere; A case study of 14th of March 2016 storm
Authors: Ellahouny Nada , Aikio Anita , Pedersen Marcus , Vanhamäki Heikki , Virtanen Ilkka , Norberg Johannes , Grandin Maxime , Kozlovsky Alexander , Raita Tero , Kauristie Kirsti , Marchaudon Aurélie , Blelly Pierre-Louis , Oyama Shin-ichiro
Published: March 2020

 Solar wind High-Speed Streams (HSSs) affect the auroral ionosphere in many ways, and several separate studies have been conducted of the different effects seen e.g. on aurora, geomagnetic disturbances, F-region behavior, and energetic particle precipitation. In this work, we study an HSS event in the solar cycle (24), which was associated with a co-rotating interaction region (CIR) that hit the Earth’s magnetopause at about 17:20 UT on 14 March 2016. The associated magnetic storm lasted for seven days, and the Dst index reached -56 nT. We use a very comprehensive set of measurements to study the whole period of this storm, following day by day for the magnetic indices and solar wind parameters and relating its consequences on ionospheric plasma parameters. We use EISCAT radar data from Tromsø and Svalbard stations to see the response in plasma parameters at different altitudes, riometer data for cosmic noise absorption, and IMAGE magnetometers to see the intensities of auroral electrojets. TomoScand ionospheric tomography provides us with electron densities over a wide region in Scandinavia and AMPERE data the global field-aligned currents. We identified 13 local substorms in the Scandinavian sector from the IL (IMAGE lower) index. Altogether, there were 11 global substorms, for which the AE index reaches 1000 nT. We discuss the development of currents, as well as E and D region precipitation during the course of this long-duration storm and compare local versus global behavior.
Micromagnetic modeling of silicate-hosted magnetic inclusions using SEM-FIB slice-and-view nanotomography
Authors: Nikolaisen Even. S. , Harrison Richard. J. , McEnroe Suzanne. A. , Fabian Karl
Published: March 2020

Slice-and-view nanotomography uses a dual beam SEM-FIB to reconstruct the 3D volume of a mineralogical sample using a sequential series of nanoscale slices created with a focussed beam of Ga ions. This method reveals the true shapes and forms of naturally occurring magnetic inclusions hosted by the silicate minerals feldspar and pyroxene. High-resolution 3D morphological data for the magnetic minerals is extracted, converted to tetrahedral meshes, and micromagnetically modelled using the MERRILL software.

This study optimises the step-by-step process of extracting and processing micromagnetic data from polished thin-sections to generate a full rock magnetic classification of the remanence carriers in silicates. Slice-and-view nanotomography follows known preparation methods with a protective platinum layer, carbon rod guides and trenches, but also introduces a carbon slab along the Z-direction for e-beam alignment. This method reduces the need for auto focus, as the e-beam alignment will have a constant imaging distance and generates a good reference point for stack alignment. Image processing is limited to 3D a gaussian blur and 3D mean filters. Paraview is used to set the correct voxel dimensions and to generate the surface mesh. Freeware software Meshmixer and Meshlab are used for their powerful smoothing, mesh interaction tools and geometric calculations. The tetrahedral volume mesh is produced with iso2mesh in Matlab.

Micromagnetic hysteresis and back-field simulations of >400 inclusions with a broad range of morphologies have been performed using MERRILL using 20 different field directions, enabling average magnetic properties to be calculated for a random ensemble. The results give a detailed and direct description of the micromagnetic structure of naturally formed magnetic minerals that compliments macroscopic approaches, such as FORC analysis.
Neogene changes in land surface reactivity and implications for Earth system sensitivity to carbon cycle perturbations
Authors: Caves Rugenstein Jeremy , Ibarra Daniel , von Blanckenburg Friedhelm
Published: March 2020

Long-term cooling, pCO2 decline, and the establishment of permanent, polar ice sheets in the Neogene has frequently been attributed to increased uplift and erosion of mountains and consequent increases in silicate weathering, which removes atmospheric CO2. However, geological records of erosion rates are potentially subject to averaging biases and the magnitude of the increase in weathering fluxes, and even its existence, remain debated. Moreover, a weathering increase scaled to the hypothesized erosional increase would have removed nearly all carbon from the atmosphere, leading to proposals of compensatory carbon fluxes in order to preserve carbon cycle mass balance. In contrast, increasing land surface reactivity—resulting from greater fresh mineral surface area or an increase in the supply of reactive minerals—rather than an increase in the weathering flux, has been proposed to reconcile these disparate views. We develop a parsimonious carbon cycle model that tracks two weathering-sensitive isotopic tracers (stable 7Li/6Li and cosmogenic 10Be/9Be) to show that an increase in land surface reactivity is necessary to simultaneously decrease atmospheric CO2, increase seawater 7Li/6Li, and retain constant seawater 10Be/9Be since 16 Ma. We find that the global silicate weathering flux remained constant, even as the global silicate weathering intensity—the fraction of the total denudation flux derived from silicate weathering—decreased, sustained by an increase in erosion. Thus, long-term cooling during the Neogene reflects a change in the partitioning of denudation into weathering and erosion. Variable partitioning of denudation and consequent changes in silicate weathering intensity reconcile marine isotope and erosion records with the need to maintain mass balance in the carbon cycle and without increases in the silicate weathering flux. These changes in land surface reactivity through time suggest that the Earth system’s response to carbon cycle perturbations is not constant and that today’s Earth can more efficiently remove excess carbon than during analogous perturbations observed in the geologic record. 
Planning a drilling campaign in a petroleum province using high resolution 3D seismic data – IODP proposal 909
Authors: Cox David , Newton Andrew M. W. , Knutz Paul C. , Huuse Mads
Published: March 2020

A drilling hazard assessment has been completed for a large area of the NW Greenland-Baffin Bay continental shelf. This assessment was in relation to International Ocean Discovery Program (IODP) proposal 909 that aims to drill several sites across the shelf in an attempt to better understand the evolution and variability of the northern Greenland Ice Sheet. The assessment utilised high quality and extensive 3D seismic data that were acquired during recent hydrocarbon exploration interest in the area – a fact that highlights the risk of drilling in a petroleum province and therefore, the importance of this assessment with regards to safety.

Scattered seismic anomalies are observed within the Cenozoic sedimentary succession covering the rift basins of the Melville Bay region. These features, potentially representing the presence of free gas or gas-rich fluids, vary in nature from isolated anomalies, fault flags, stacked fluid flow features and canyons; all of which pose a significant drilling risk and were actively avoided during site selection. In areas above the Melville Bay Ridge – a feature that dominates the structure of this area – free gas is also observed trapped beneath extensive gas hydrate deposits, identified via a spectacularly imaged bottom simulating reflector marking the base of the gas hydrate stability zone. The location of the hydrate deposits, and the free gas beneath, are likely controlled by a complicated migration history, due to large scale rift-related faulting and migration along sandy aquifer horizons. In other areas, gas is interpreted to have reached the shallow subsurface due to secondary leakage from a deeper gas reservoir on the ridge crest.

It is clear that hydrocarbon related hazards within this area are varied and abundant, making it a more challenging location to select sites for an IODP drilling campaign. However, due to the extensive coverage and high resolution (up to 11 m vertical resolution (45 Hz at 2.0 km/s velocity) of the 3D seismic data available, as well as the use of recently acquired ultra-high resolution site survey lines, these features can be accurately imaged and confidently mapped. This allowed for the development of a detailed understanding of the character and distribution of fluids within the shallow subsurface, and the use of this knowledge to select site localities that maximise the potential for drilling to be completed safely and successfully if proposal 909 were to be executed.
Multi-millennial legacy of climate change in marine plankton communities
Authors: Strack Anne , Jonkers Lukas , Rillo Marina C. , Hillebrand Helmut , Kucera Michal
Published: March 2020

Understanding the response of marine ecosystems to climate change requires knowledge of processes that operate over long time scales. Over the last decades, abundant data have been generated on the change in the composition of marine microplankton assemblages across the last deglaciation. These data were used to reconstruct various aspects of the ocean and climate system during this climatic upheaval; however, their potential to evaluate biotic response to climatic forcing has been rarely explored. Here, we compiled records of plankton response to the last deglaciation covering the entire North Atlantic Ocean. The records comprise assemblage composition data of marine zooplankton (planktonic foraminifera) and phytoplankton (coccolithophores, diatoms and dinoflagellates) covering the last 24 ka with a resolution of at least 1 ka. The comparability of the data is ensured by using either published age models or a combination of radiocarbon ages and correlated oxygen isotope data. We use these records to first determine the shape of the major compositional change in each record by principle components analyses and quantification of compositional turnover. The mean global response of the plankton to the deglaciation was then evaluated by an Empirical Orthogonal Function analysis of the main biotic trends across all sites. A preliminary analysis was run solely on the zooplankton data set as the phytoplankton data set is still work in progress. We find that the dominant response of the zooplankton consists of synchronous unidirectional shifts initiated between 16-17 ka BP, and progressing into the Holocene. When regressed on the global ocean temperature and CO2 trends, we can see a proportionate response to the forcing during the last glacial maximum, the deglaciation and the early Holocene. In contrast, the late Holocene is characterised by continued compositional change, which does not appear related to environmental forcing. We speculate that this decoupling indicates the existence of a multi-millennial delay in community change following the climatic forcing, likely due to biotic interactions acting on communities that have been newly assembled or geographically displaced due to abiotic forcing. We will present a similar analysis for marine phytoplankton and discuss the consequences of the observations for the understanding of community variability on millennial time scales.
Stress orientation variability along the Hikurangi Subduction Margin: Insights from borehole image logging
Authors: Behboudi Effat , Lokmer Ivan , McNamara David , Manzocchi Tom , Wallace Laura , Saffer Demian , Barnes Philip , Pecher Ingo , Lee Hikweon , Kim Gil Young , Wu Hung-Yu , Petronotis Katerina , LeVay Leah , Expedition372 Scientists Iodp , Expedition375  Scientists Iodp
Published: March 2020

The Hikurangi Subduction Margin (HSM) of New Zealand is well-known for its variable seismic behaviour along strike, and across the Pacific-Australian subduction interface. Pacific-Australian plate motion is accommodated by a combination of slow slip and normal seismic events. The mechanics of slow slip earthquakes and their relationship to normal earthquakes are not well constrained, and so they represent a challenge to the development of hazard models for this region of New Zealand.Variability in a number of aspects of the stress state along the HSM may play a role in controlling the observed spatially variable seismic behaviour. Here we present preliminary analysis of stress orientation information from borehole image logs acquired from oil and gas exploration wells, and scientific wells drilled as part IODP Expedition 372. Orientations of borehole breakouts (BOs) and drilling-induced tensile fractures (DITFs) from these image logs are used to determine orientations of the minimum and maximum horizontal stress directions respectively within the upper 3 km of the over-riding Australian Plate (hanging wall of the HSM subduction interface). Our analysis reveals that present day maximum horizontal compressive stress orientation (SHmax) within the subduction hangingwall varies along the HSM strike, from NE-SW (oblique to Pacific-Australian plate motion, parallel to HSM strike) in the northern HSM, to NW-SE (oblique to Pacific-Australian plate motion and HSM strike) in the southern HSM. Some deviation from this trend can be observed in both regions. At the frontal thrust in the northern HSM, SHmax is oriented N-S, and in the southern HSM one well shows a shallow E-W oriented SHmax. The borehole image log SHmax orientations in the northern HSM are consistent with SHmax orientations derived from shallow focal mechanism inversion. In contrast, borehole image logs SHmax orientations in the south of HSM are oblique to focal mechanisms derived shallow SHmax orientations. Borehole SHmax orientations are compatible with the maximum horizontal contraction strain rate direction determined from campaign GPS surface velocities, though in the southern HSM multiple directions are determined from this technique. The difference in stress orientations along the HSM is consistent with the variation in seismic behaviour linked to changes in coupling at the subduction interface. Interestingly, it is the southern HSM, where the subduction interface is considered strongly coupled, that stress field orientations are not consistent with depth and show variability. In the northern HSM, where the subduction interface is considered to be weakly coupled, stress orientations appear broadly consistent with depth. 
Effects of land use change and grazing on soil carbon dynamics in the semi arid Chaco, Argentina
Authors: Durcan Rose , Rufino Mariana , Ostle Nick , Banegas Natalia , Viruel Emilce
Published: March 2020

In recent years deforestation of the Gran Chaco of Argentina has increased dramatically to make way for agricultural expansion.  Extensive cattle ranching in particular is widespread across the country, and in the Chaco region of the north west much of the natural vegetation has been cleared for beef and crop production.  The effects of forest clearance and grazing over time on soil carbon dynamics are unclear, with some evidence suggesting that soil carbon can to some extent recover under low intensity grazing practices, whilst others find that conversion to pasture followed by years of grazing consistently decreases soil carbon stocks.  This study investigates the effects of land use change from forest to pasture over time on soil carbon stocks in the dry Chaco of north western Argentina, through the measurement of biological, physical and chemical variables within the soil.  The hypothesis leading to this work is the key idea that livestock grazing can promote the accumulation of carbon in the soil over time through processes such as the stimulation of root growth of pasture grasses.  In turn, increased carbon inputs can lead to net carbon sequestration, with great potential to mitigate the greenhouse gas emissions of the livestock sector.  Using a chronosequence experimental design, destructive soil samples were taken from reference forest patches and pastures of 0-5, 10-15 and >20 years since deforestation and were tested for carbon, nitrogen, and phosphorus contents, root biomass, pH, electrical conductivity and texture. The research aims to investigate and explain the carbon dynamics of pastures in the years following deforestation, identify potential biotic and abiotic drivers of such dynamics, and predict potential future changes in soil carbon stocks.
Fast and slow components of millennial-scale climate changes
Authors: Tzedakis Chronis , Margari Vasiliki , Skinner Luke , Menviel Laurie , Capron Emilie , Rhodes Rachael , Vautravers Maryline , Ezat Mohamed , Martrat Belen , Grimalt Joan , Hodell David
Published: March 2020

Despite a substantial body of evidence on millennial-scale climate variability during Marine Isotope Stage 3, uncertainty remains over the precise sequence of changes in different parts of the climate system, and ultimately their causes.  Here, we present results of joint marine and terrestrial proxy analyses from the Portuguese Margin, showing the typical succession of cold stadials and warm interstadials over the interval 35-57 ka, with most extreme changes occurring during Heinrich Stadials (HS).  The planktonic and benthic foraminiferal isotope records map onto Greenland and Antarctic temperature variations, respectively, while the pollen record bears a close similarity to changes in the Asian summer monsoon, atmospheric methane and dust concentrations, indicating coupled changes in hydroclimate in middle-to-low latitudes.  Closer inspection of HS4 and HS5 reveals considerable structure, with a relatively fast transition to maximum cooling and aridity associated with a peak in ice-rafted detritus, containing detrital carbonate grains originating from the Hudson Strait.  This was followed by an interval of slowly increasing sea-surface temperatures (SST) and moisture availability, in line with evidence indicating a gradual evolution in low-latitude hydroclimate.  A climate model experiment closely reproduces the gradual increase in SST and precipitation in W. Iberia during the final part of HS4 as a result of the recovery of the Atlantic overturning circulation, but does not capturethe abrupt warming in Greenland.  What emerges is a diversity of response timescales, from centuries in low-to-mid latitude SST and precipitation to decades in Greenland temperatures.
Early Warning System for West Nile Virus outbreaks based on Satellite Earth Observation Data
Authors: Parselia Elisavet , Kontoes Charalambos , Kioutsioukis Ioannis , Mourelatos Spiros , Hadjichristodoulou Christos , Stilianakis Nikolaos I.
Published: March 2020

The aim of this study is the development of an operational Early Warning System (EWS) that will utilize new and enhanced satellite Earth Observation (EO) sensors with the purpose of forecasting and risk mapping the West Nile Virus (WNV) outbreaks. Satellite EO data were leveraged to estimate environmental variables that influence the transmission cycle of the pathogen that leads to WNV, a mosquito-borne disease (MBD). The system was trained with epidemiological and entomological data from the region of Central Macedonia, the most epidemic-prone region in Greece regarding the WNV. The satellite derived environmental parameters of the Normalized Difference Vegetation Index (NDVI), the Normalized Difference Water Index (NDWI), the Land Surface Temperature (LST), precipitation data as well as proximity to water bodies were coupled with meteorological data and were used as explanatory variables for the models. The management and analysis of the big satellite data was conducted with the Open Data Cube (ODC), providing an open and freely accessible exploitation architecture. Statistical and machine learning algorithms were used for short-term forecast, while dynamical models were utilized for the seasonal forecast.The system explores the analysis of big satellite data and proves its scalability by replicating the same models in different geographic regions; e.g the northeastern Italian region of Veneto. This EWS will be used as a tool for helping local decision-makers to improve health system responses, take preventive measures in order to curtail the spread of WNV in Europe and address the relevant priorities of the Sustainable Development Goals (SDGs) such as good health and well-being (SDG 3) and climate action (SDG 13).
How an adaptive and flexible short-term flood planning can be beneficial - a UK case study application
Authors: Ni Mengke , Erfani Tohid
Published: March 2020

Short term flood intervention planning includes identifying how the limited resources should be allocated to the most appropriate affected locations. The water level is an important factor for temporary flood protection planning for which adaptability of the plan to its changing future condition is regarded valuable. Moreover, flexibility in activation, delaying and replacement of the existing plans should be considered to mitigate the damages caused by future unknown condition. This research applies real options analysis which incorporates adaptability and flexibility in addressing “least-cost alternative”  location selection via multi-stage stochastic programming. We apply the proposed model to a case study in Eden catchment with nine different flood-affected cities with different degrees of uncertainty along Eden River in England. A multi-objective and mixed integer optimization model was formulated to solve on a scenario tree capable to choose most appropriate locations for deploying intervention measures of temporary flood protection. We examine the solution under various model parameters uncertainty and compare the results with the business as usual case presenting the benefits of proposed formulation in terms of expected damage and cost.
Wastewater as a potential source of microplastics in aquatic environments
Authors: Adyel Tanveer M.
Published: March 2020

Rapid increasing production and utilization of microplastics (MPs) raise concerns about environmental risks globally. Literature indicates that wastewater and wastewater treatment plants (WWTPs) play critical sources in releasing MPs to the environment. Among different MPs, microbeads added into the facial cleanser, and toothpaste can be directly discharged into wastewater through human activities. Synthetic clothing, i.e., polyester (PES) and nylon, might shed thousands of fibers into wastewater during the washing process. WWTPs are not designed to capture MPs, and therefore, a huge amount of MPs load can be discharged without or poor treatment, and can accumulate in aquatic environments. This work shows a comprehensive overview of available information on the presence of MPs in different freshwater environments, particularly rivers, along with MPs types, sizes, shapes, and properties. Moreover, the study also indicates significant technical advancement in MPs detection, characterization, and quantification from the complex sample matrix.
A dynamical systems approach to optimizing irrigation strategy under the influence of land-atmosphere feedbacks.
Authors: Meyer Bettina , Parker Douglas J. , Haerter Jan O.
Published: March 2020

The soil-moisture feedback describes how precipitation amount, timing and intensity react to spatial anomalies in surface moisture. For heterogeneous moisture distributions with moist/dry patches on the scale of 10− 50km, numerical studies supported by observations indicate a negative soil-moisture feedback, where it rains more over dry patches (Imamovic, 2018; Rieck et al., 2014). The circulation established by the heterogeneous soil-moisture patches not only modifies the spatial rain distribution but allows for more water to be extracted from the atmosphere, thereby increasing the domain mean precipitation.

We here suggest that the negative soil-moisture feedback can be exploited when irrigating agricultural land: if farmers cooperate by following a spatially heterogeneous irrigation pattern, they can increase both their collective time-mean precipitation and thus the total water available for growing crops. However, the spatially non-local nature of the feedback allows individual farmers to exploit this strategy, thereby saving their own resources; a typical ‘tragedy of commons’ situation.
We formulate this setup in terms of an optimisation problem and study its parameter phase space, both analytically and numerically, in order to understand optimal rules and the consequences of the players’ choice to cooperate vs. compete. Different constraints in terms of water availability (reservoir) and average soil moisture as defined by the evaporation timescale are explored.

Reducing the details of the land-atmosphere interaction into simple feedback parameters helps to elucidate the complex interactions between the precipitation, soil moisture and the human intervention by irrigation. Taking into account the negative soil-moisture feedback in irrigation models opens up new strategies to optimise water management and thereby increase crop yield.
Developing a South‐Eastern European Multi‐Hazard Early Warning Advisory System
Authors: Wetterhall Fredrik , Modigliani Umberto , Dacic Milan , Lappi Sari
Published: March 2020

The project “South-East European Multi-Hazard Early Warning Advisory System” (SEE-MHEWS-A) is a collaborative effort to strengthen the existing early warning capacity in the region. The project was initiated in 2014 by the World Meteorological Organization (WMO), and has been supported by the U.S. Agency for International Development (USAID) and the World Bank. The project will test a prototype of a flood early warning system using local information and multiple models to better characterize the flood risk in selected catchments. The aims of the project are: (1) is to strengthen regional co-operation by leveraging national, regional and global capacities to develop improved hydrometeorological forecasts, advisories and warnings to save lives and limit economic losses, (2) strengthen national multi-hazard early warning systems by making tools and data available to the participating countries and other beneficiaries, (3) implement impact-based forecasts and risk-based warnings utilizing non-deterministic hydrometeorological modeling to support governments, disaster management authorities, humanitarian agencies, non-governmental organizations, and other stakeholders in their decision-making and actions, and (4) to harmonise forecasts and warnings in trans-boundary areas. During 18 month the project will setup a full-hydrometeorological forecasting system, including observational data storage and sharing, limited area modelling of the meteorological forcing data and hydrological forecasting.
Geostatistical inversion of electromagnetic induction data for landfill modelling
Authors: Narciso João , Azevedo Leonardo , Van Meirvenne Marc , Van De Vijver Ellen
Published: March 2020

The characterization and monitoring of landfills has become a major concern, not only for assessing the associated environmental impact (e.g., groundwater contamination) but also for evaluating the potential for recovery of secondary resources, in particular for the production of raw materials and energy. For both objectives, it is crucial to have knowledge of the waste composition and the current landfill conditions (e.g. water saturation level). Near-surface geophysical surveys have been proven effective for the non-invasive investigation of landfills, in which different methods have been used depending on the specific survey targets.  Because of its sensitivity to two subsurface physical properties, electrical conductivity (EC) and magnetic susceptibility (MS), frequency-domain electromagnetic (FDEM) induction has been successfully applied to the qualitative characterization of urban and industrial landfills, including mine tailings. Yet, due to the generally complex composition and strongly heterogeneous spatial distribution of waste deposits, reconstructing a reliable landfill model from surface geophysical measurements remains challenging. Geostatistical inversion emerges as powerful tool to improve the landfill modelling from geophysical data, allowing for a more detailed description of the spatial distribution of the properties of interest and the associated uncertainty. Additionally, it provides a flexible framework for integrating data from geophysical surveys and conventional sampling from drilling or trenching.

In this work, we present a new geostatistical inversion technique able for the simultaneous inversion of FDEM data for EC and MS, which optimize the landfill modelling procedure and is sensitive towards change on the physical properties of interest. This method is based on an iterative procedure where ensembles of subsurface models of EC and MS are generated with stochastic sequential simulation and co-simulation. These simulated models are conditioned locally by existing borehole data for these properties and by a spatial continuity pattern imposed by a variogram model. Synthetic instrument response data, including both the in-phase and quadrature-phase components of the FDEM response, are generated from each model using a forward model connecting the data domain (FDEM data) with the model domain (subsurface physical properties). The misfit between the observed and forward-modelled FDEM data, weighted according to the depth sensitivity of the FDEM response toward changes in EC and MS, is used to drive the generation of a new set of models in the next iteration. We illustrate the inversion procedure with synthetic landfill example data sets which were created based on real data collected at a mine tailing in Portugal and a municipal solid waste landfill in Belgium.