bluuebunny/crossref_metadata_2025 huggingface dataset:
MEMS Accelerometers Mini-Array (MAMA) - initial results and lessons learned
Authors: Nof Ran N. , Chung Angela I. , Rademacher Horst , Allen Richard M.
Published: March 2020

Most operational earthquake early warning systems (EEWS) consider earthquakes to be point-sources and have difficulty providing imminent and robust source locations and magnitudes, especially at the edge of the seismic network or where seismic stations are sparse. Mini-arrays have the potential to estimate reliable hypocentral locations by beam forming (FK-analysis) techniques. They can also characterize the rupture dimensions and account for finite-source effects, leading to more reliable estimates of ground motions for large magnitude earthquakes. In the past, the high price of multiple seismometers has made creating arrays cost- prohibitive. Here, we present a setup of two mini-arrays of a new low-cost (<$150) seismic acquisition unit based on a high-performance MEMS accelerometer around conventional seismic stations. The expected benefits of such an approach include decreasing alert-times, improving real-time shaking predictions and mitigating false alarms.

We will present our new 24-bit device details, benchmarks, and results from two MAMAs deployed at the UC Berkeley and Humboldt State University campuses. The new device shows lower noise levels than the currently available off-the-shelf 16-bit sensors, commonly used by several citizen-science projects (e.g. QCN, CSN, MyShake, etc.). This lower noise level enables us to record and process lower magnitude events. We show examples of back-azimuth calculations of M>=2.5 events at a range of <100km from the MAMA center and discuss some of the limitations and considerations of the MAMA deployments.
Palaeoenvironmental development of the accumulative fan in Western Russia from the Little Ice Age to the present time
Authors: Piech Wiktor , Kittel Piotr , Ginter Artur , Mazurkevich Andrey , Hrynowiecka Anna , Stachowicz-Rybka Renata , Cywa Katarzyna , Mroczkowska Agnieszka , Pavlovskaia Elena , Kazakov Eduard , Teltevskaya Yulia , Sikorski Jarosław , Okupny Daniel , Błaszczyk Krzysztof , Kotrys Bartosz
Published: March 2020

The accumulative fan was formed at the mouth of a well-developed system of erosive cuts in the lower Serteyka River valley in western Russia. The length of the fan reaches 70 m, and its thickness is up to 2 m. The erosive cuts (gullies) were formed on the steep and short slopes of the tunnel valley (transformed later into the river valley) and dissect the surface of the glaciofluvial plain for a length of ca. 110 meters. The absolute chronology of the development of that relief form was determined based on 14C and 210Pb data set. It was started at the earliest in the second half of the 17th century, and finished before the mid-19th c. AD. These processes can be correlated therefore with palaeoenvironmental changes during the pessary of the Little Ice Age (LIA), as well as with human impact during the agrarian and industrial revolution in Eastern Europe. Studied accumulative fan is formed of deluvium with the insertion of the proluvium and an agricultural diamikton which is developed in ceiling part. The research based on the results of analysis of depth diversity of textural features (mean grain-size diameter, sorting index, skewness and kurtosis), geochemical features (chemostratigraphy determined on the basis of X-ray fluorescence spectroscopy – XRF) of the fan’s sediments and palaeoecological features (palynology analysis, subfossil Chironomidae and Cladocera analysis, plant macrofossil analysis) of biogenic deposits from under the fan.
Thickness-Dependent Oxidation Kinetics of Coated Films of a Self-Assembled Unsaturated Fatty Acid Aerosol Proxy with Evidence for Inert “Crust” Formation
Authors: Milsom Adam , Squires Adam M. , Ward Andrew D. , Terrill Nicholas J. , Pfrang Christian
Published: March 2020

This study focuses on the effect of surface film thickness on the ozone reaction kinetics of films of a self-assembled unsaturated fatty acid aerosol proxy coated inside quartz capillaries. It also reveals evidence for reaction stagnation and stopping for the thickest films, leaving a significant amount of unreacted material and suggesting that an inert product is formed during the course of the reaction. These findings have implications for the atmospheric lifetime of such a system.

The oleic acid-ozone reaction is used as the model system for heterogeneous oxidation reactions in organic aerosols. Major sources of oleic acid in the atmosphere include marine and cooking emissions. Oxidation of organic aerosols is known to affect Cloud Condensation Nuclei (CCN) generation and therefore cloud formation. It follows that factors affecting aerosol reactivity have an effect on cloud formation potential and therefore also on the climate.

In our experiments, oleic acid is mixed with its sodium salt (sodium oleate) to form a highly viscous self-assembled lamellar phase system observable using a synchrotron-based technique: Small Angle X-ray Scattering (SAXS). Here, we take advantage of intense synchrotron radiation to probe our coated capillary films. We use the observed decay of the self-assembled scattering peak as a function of time exposed to ozone. We have obtained ~50 kinetic decay parameters spanning a range of film thicknesses, showing a drastic increase in reaction kinetics with decreasing film thickness.

There is a linear relationship between increasing film thickness and amount of self-assembled material (reactant) remaining at the end of the reaction. This implies that a reaction product hinders further reactivity and that this product may take a while to form, explaining the occurrence only in thicker films.

Modelling studies will help us understand the mechanism behind these observations and to relate to a previously-postulated idea of an inert “crust” of products forming on the surface of this viscous aerosol proxy (Pfrang et al., Atmos. Chem. Phys., 2011, 11, 7343-7354).

In summary, we demonstrate thickness-dependent reaction kinetic parameters which vary significantly with film thickness, implying that the atmospheric lifetime for a film is sensitive to the film thickness. We present evidence for reaction stagnation by an as of yet unknown inert product. Kinetic modelling is ongoing in order to explain these findings.
Is the hydrological response of Nature-Based Solutions related to the spatial variability of rainfall?
Authors: Qiu Yangzi , Tchiguirinskaia Ioulia , Scherzter Daniel
Published: March 2020

Nature-Based Solutions (NBS) practices provide many benefits for sustainable development of urban environments, one of which is their ability to mitigate the urban waterlogging. In many previous studies, the performances of NBS practices are analysed with the semi-distributed model and artificial rainfall without considering the spatial variability of rainfall. However, the NBS practices are decentralized in urban areas, their hydrological response is very depends on the small-scale heterogeneity of urban environments. Therefore, this research aims to investigate the impacts of small-scale rainfall variability on the hydrological responses of NBS practices.

In this study, the hydrological response of NBS practices was analysed at the urban catchment scale. A 5.2 km2 semi-urban catchment (Guyancourt, located in the South-West of Paris) are investigated under various future NBS implementation scenarios (porous pavement, green roof, rain garden and combined). Regarding the objective of this research, three typical rainfall events are selected. Three sets of distributed rainfall data at a high resolution of 250 m×250 m×3.41 min were obtained from the X-band radar of Ecole des Ponts ParisTech (ENPC). In addition, three sets of corresponded homogeneous rainfall data are applied and used for comparing with the distributed one. Furthermore, a fully distributed and grid based hydrological model (Multi-Hydro), developed at ENPC, which takes into consideration the spatial variability of the whole catchment at 10 m scale. The hydrological response of NBS scenarios was analysed with the percentage error on total volume and peak discharge, with regards to the baseline scenario (current configuration).

Results show that the spatial variability of rainfall has the impact on the hydrological response of NBS scenarios in varying degrees, and it is more evident for green roof scenario. In three rainfall events, the maximum percentage error on peak discharge of green roof scenario under distributed rainfall is 23 %, while that of the green roof scenario under homogeneous rainfall is 17.7%. Overall, the results suggest that the implementation of porous pavement and rain garden is more flexible than implementation of green roof in a semi-urban catchment.
Assessing the performance of radar-based and satellite precipitation products in hydrological modelling with SWAT in Vils Basin, Germany
Authors: Duan Zheng , Duggan Edward , Qing Ye , Tuo Ye
Published: March 2020

Hydrological modelling is an important tool to improve our understanding of hydrological processes of river basins and to predict impacts of climate change and environmental change on water resources. Precipitation is a key component of the hydrological cycle, and the most important driver/input data for hydrological models. Accurate precipitation measurements at desirable temporal and spatial resolution are essential for achieving reasonable performance of hydrological modelling. Compared to the conventional measurements from point-based rain gauge stations, remote sensing of precipitation with satellite sensors and ground-based radar can expand observational coverage and provide regional precipitation at varying temporal and spatial resolutions. Radars can provide sampling at very high resolution but also tend to contain significant errors in precipitation estimates. The Deutscher Wetterdienst (DWD; German Weather Service) developed the RADOLAN (RADar-OnLine-ANeichung) method (a real-time, gauge-adjustment and correction procedure) to generate precipitation estimates (termed as RADOLAN product) from the German Doppler radar network. More recently (2017), the DWD published a reanalysis of radar data to generate RADKLIM (RADarKLIMatologie) precipitation product using upgraded correction algorithms and additional offline gauge adjustment. 

 

This study presents the first assessment of the performance of two high spatial resolution (1 km) radar-based precipitation products (RADOLAN and RADKLIM) in streamflow simulation using the hydrological model SWAT (Soil and Water Assessment Tool) in Germany. We also evaluate the performance of conventional point-based rain gauge data and a satellite precipitation product in driving SWAT for streamflow simulation. The selected satellite product is CHIRPS (Climate Hazards Group InfraRed Precipitation with Station data) because of its well reported good performance and the relative higher spatial resolution (0.05°). The Vils Basin located in Bavaria, Germany is chosen as the study area. Performance of investigated precipitation product is assessed by comparing simulated streamflow using calibrated SWAT model against measured streamflow at basin outlet at both daily and monthly time scales. The model calibration is performed using the SWAT-CUP program with measured streamflow. Different calibration procedures are also investigated to analyze the influence on model performance. This study presents and discusses the accuracy and uncertainty of using ground-based radar and satellite precipitation products in driving SWAT model for daily and monthly streamflow simulation. Our findings are expected to provide beneficial feedback to product developers for further improvements, and to inform local end-users about the quality of investigated precipitation products.
Large-scale features of Last Interglacial climate: Results from evaluating the lig127k simulations for CMIP6-PMIP4
Authors: Otto-Bliesner Bette L. , Brady Esther C. , Zhao Anni , Brierley Chris ,   PMIP4 and QUIGS team
Published: March 2020

The modeling of paleoclimate, using physically based tools, is increasingly seen as a strong out-of-sample test of the models that are used for the projection of future climate changes. New to CMIP6 is the Tier 1 lig127k experiment, designed to address the climate responses to stronger orbital forcing than the midHolocene experiment, using the same state-of-the-art models and following a common experimental protocol. We present a multi-model ensemble of 17 climate models, all of which (except for two) have also completed the CMIP6 DECK experiments. The Equilibrium Climate Sensitivity (ECS) of these models varies from 2.1 to 5.3°C. The seasonal character of the insolation anomalies results in strong warming over the Northern Hemisphere (NH) continents in the lig127k ensemble as compared to the piControl in June-July-August and a much-reduced minimum (August-September) summer sea ice extent in the Arctic. The multi-model results indicate enhanced summer monsoonal precipitation and areal extent in the Northern Hemisphere and reductions in the Southern Hemisphere. These responses are greater in the lig127k than midHolocene simulations as expected from the larger insolation anomalies at 127 ka than 6 ka.

New syntheses for surface temperature and precipitation, targeted for 127ka, have been developed for comparison to the multi-model ensemble. The lig127k model ensemble and data reconstructions are in good agreement for summer temperature anomalies over Canada, Scandinavia, and the North Atlantic and precipitation over the Northern Hemisphere continents. The model-data comparisons and mismatches point to further study of the sensitivity of the simulations to uncertainties in the specified boundary conditions and of the uncertainties and sparse coverage in current proxy reconstructions.

The CMIP6-PMIP4 lig127k simulations, in combination with the proxy record, have potential implications for confidence in future projections of monsoons, surface temperature, Arctic sea ice, and the stability of the Greenland ice sheet.
Structure of the SW Iberian Margin from Combined Wide-angle and Multichannel Seismic Reflection Data (FRAME Project)
Authors: Correia Ricardo , Prada Manel , Sallares Valenti , Merino Irene , Calahorrano Alcinoe , M. Pinheiro Luis , R. Ranero César
Published: March 2020

The SW Iberian Margin has a complex tectonic setting and crustal structure derived from a succession of rift events related to the opening of North Atlantic and Neotethys, from the Mesozoic to the Lower Cretaceous, and subsequent compression between Africa and Eurasia from the Lower Oligocene to present. This setting led to the reactivation of pre-existing strike-slip and extensional faults enhancing the seismogenic and tsunamigenic potential of the area. Thus, understanding of lithospheric structure along the SW Iberian Margin is not only important to study the rifting evolution but also to characterize the distribution of major lithospheric-scale boundaries, currently active and potentially capable of generating great seismic events of similar magnitude to the catastrophic 1755 Lisbon tsunamigenic earthquake, with estimated MW>8.5.

To this end, we use spatially coincident wide-angle seismic (WAS) and multichannel seismic (MCS) data collected along a ~320 km-long, NW-SE trending transect across the SW Iberian margin, during the FRAME survey in 2018. WAS data were recorded with by 24 ocean bottom seismometers and hydrophones (OBS/H), deployed each ~10km, while MCS data was recorded with a 6 km-long streamer. From NW to SE, the transect runs from the Tagus Abyssal plain to the westernmost extension of the Gulf of Cadiz area, across three major thrust faults: the Marquês de Pombal fault, São Vicente fault, and Horseshoe fault.

We applied joint refraction and reflection travel-time tomography using a combination of WAS refractions and reflections and MCS reflections to invert for the 2D P-wave velocity structure of the crust and uppermost mantle, and the geometry of the main seismic interfaces, namely the top of the acoustic basement and the Moho. The combination of WAS and MCS reflection travel-times brings a significant increase in the resolution of the tomographic model, and especially in the definition of the geometry of the inverted reflectors (i.e. top of the basement), because MCS data has a higher spatial sampling than WAS data in these shallow regions.

In the preliminary model, the Moho shallows beneath the north-eastward continuation of the Horseshoe Basin and the Gorringe Bank, coinciding with the location of the three major thrust faults mentioned before, and defining three major crustal blocks along the model. Further analysis of deep seismic phases from WAS records should provide additional information on the geometry and extent of these three major thrust faults.
Western Europe tectonic evolution : probing the relative role of inheritance and sub-lithospheric processes
Authors: Mouthereau Frédéric , Angrand Paul , Rat Juliette , Daudet Maxime
Published: March 2020

Abstract : The heterogeneous continental lithosphere of Western Europe inherits billion of years of tectonic evolution, mineral transformation and magmatic addition. Its deformation over broad regions form collisional orogens and large forelands basins, which tectonic evolution is controlled by the interactions between its inherited properties, large-scale plate convection and smaller-scale plate subduction. How these first-order interactions are connected through time and space to control collision evolution is however largely unknown. Here we explore the evolution of the Alpine collision along a transect stretching between northern Africa and Europe. We show that the complex patterns of Alpine deformation from the Rif-Betic, Pyrenean collision and Europe primarily reflects continental fragmentation and drastic weakening of the lithosphere that occurred during the Late Permian-Triassic. Subsequent rifting episodes from Jurassic to Early Cretaceous left imprints on the thermal evolution of sedimentary basins, together with significant increase of Iberia topography, asthenospheric flow, and plate-scale dispersion of terrigenous sediments. The lack of large oceanic domain, at the transition between Atlantic and western Tethys, resulted in the distributed of shortening over a broad region from north Africa, Iberia and Europe, in the upper Cretaceous (~70 Ma). Detailed contraints on the sequence of shortening throughout West Europe from Late Cretaceous to the Tortonian reveals that the overall evolution of the west-alpine orogenic domain is primarily controlled by the nature and architecture of the continental lithosphere but became progressively controlled by sub-lithospheric processes associated with late/post-orogenic tectonic evolution.  
Sea ice classification using wide-swath SAR data considering incidence angle depenency of backscatter intensity and surface texture
Authors: Guo Wenkai , Itkin Polona , Philipp Lohse Johannes
Published: March 2020

In this study we develop a novel sea ice classification scheme based on remote sensing Synthetic-aperture Radar (SAR) data, and use it to classify sea ice types over the spatial and temporal range of the Norwegian Young sea ICE cruise (N-ICE2015). Ice type classification will be conducted on wide-swath SAR datasets including RADARSAT-2 and Sentinel-1 data. We use a classification scheme that takes into account different rates of decrease in backscatter intensity with incidence angle variation for different classes. In addition, it examines texture features of different sea ice types, and also variations of surface texture with changing incidence angles, and incorporates this relationship into the classification process. Sea ice classifications using high-resolution SAR images collected over the same period and also field data retrieved from the N-ICE2015 expedition will be used for ground truthing. Earlier N-ICE2015 studies with high resolution SAR and deformation suggest high lead and pressure ridge formation. We will use our lower-resolution results to explore potential increase in the fraction of deformed and lead ice from January to June 2015 in the region north of Svalbard.
An approach towards addressing meteorological factors for extreme event impacts
Authors: Ulbrich Uwe , Grieger Jens
Published: March 2020

The ClimXtreme program funded by the German Ministry of Education and Research is designed to address Physics and Processes, Statistics, and Impacts of meteorological extreme events, considering both the past period covered by instrumental measurements, and future climate scenarios. In its branch on impacts, the impact of hazards in Europe (convective events, severe precipitation, heat waves and droughts, and large scale storms) shall be considered in order to identify the underlying relevant weather situations and the antecedent meteorological factors. The specific characteristics of the extreme events shall also be explored. Aiming at a better understanding of the impacts of the extremes, investigations shall go beyond quantification of the local severity of a hazard. The assumption is that there is also an influence of weather and climate on exposure and vulnerability. These factors for the occurrence and the magnitude of damaging impacts  thus depend on local climatology, the occurrence of specific weather sequences augmenting vulnerability, or the occurrence of specific combinations of factors which individually needn’t be extreme (compound events).  One starting point are thus already existing impact models, which do not take (all of) these factors into account. Results from numerical climate models will be used to estimate the future change of risks under climate change.
Ice aprons on steep North faces: oldest surface ice in the Alps?
Authors: Ravanel Ludovic , Preunkert Suzanne , Guillet Grégoire , Kaushik Suvrat , Magnin Florence , Deline Philip
Published: March 2020

Ice aprons are small but ubiquitous ice masses in high alpine ranges such as the Mont Blanc massif. Mainly present on its north faces above 3200 m a.s.l., they are a condition for practice of the so-called "traditional" mountaineering (now on the Intangible Cultural Heritage UNESCO list) and an indicator of the presence of permafrost in the bedrock. Most often thin (<10 m), these ice aprons are very sensitive to increasing air temperatures while their evolution during the recent decades suggests many coming disappearances in the short term and, consequently, a change in the permafrost thermal regime and a related increase in the rockfall occurrence.

Very few studied, ice aprons however represent an important glacial inheritance. We suggest that ice aprons are made up of very old ice, likely the oldest surface one in the Alps. In the north face of the Mont Blanc du Tacul (4248 m a.s.l.) for example, following the disappearance of the upper layers due to the increased occurrence of summer heatwaves, the ice on the present surface formed c. 2700 ago years (cold phase of Göschener I), against probably 200-300 years for the ice at the front of the Mer de Glace, the largest glacier in the French Alps. We present the ice ages acquired from five ice aprons on rock walls of the Mont Blanc massif together with ice ages from two glacier tongues of the massif (Mer de Glace and Miage Glacier).
What controls b-value variations: insights from a physics based numerical model
Authors: Dublanchet Pierre
Published: March 2020

The magnitudes of earthquakes are known to follow a power-law distribution, where the frequency of earthquake occurrence decreases with the magnitude. This decay is usually characterized by the power exponent, the so-called b-value. Typical observations report b-values in the range 0.5-2. The origin of b-value variations is however still debated. Seismological observations of natural seismicity indicate a dependence of the b-value with depth, and with faulting style, which could be interpreted as a signature of a stress dependence. Within creeping regions of major tectonic faults, the b-value of microseismicity increases with creep rate. Stress dependent b-value of acoustic emissions is also commonly reported during rock failure experiments in the laboratory. Natural and laboratory observations all support a decrease of b-value with increasing differential stress. I report here on the origin of b-value variations obtained in a fault model consisting in a planar 2D rate-and-state frictional fault embedded between 3D elastic slabs. This model assumes heterogeneous frictional properties in the form of overlapping asperities with size-dependent critical slip distance distributed on a creeping segment. This allows to get complex sequences of earthquakes characterized by realistic b-values. The role of frictional heterogeneity, normal stress, shear stress, and creep rate on the b-value variations is systematically explored. It is shown that the size distribution of asperities is not the only feature controlling the b-value, which indicates an important contribution from partial ruptures, and cascading events. In this model cascades of events (and thus b-value) is strongly influenced by frictional heterogeneity and normal stress through fracture energy distribution. If the decrease of b-value with differential stress is reproduced in these simulations, it is also shown that part of the b-value fluctuations could be attributed to changes of nucleation length and stress drop with normal stress. A slight increase of b-value with slip rate exists but remains an order of magnitude smaller than the observations.
Efficacy of slow-release system for improving the quality of water in streams affected by mining activities
Authors: Lee Eung Seok , Wolbert Ryan
Published: March 2020

Acid mine drainage (AMD) is considered as one of the most prevalent environmental problems worldwide and remediation of AMD-affected streams remains a major challenge due to the large affected areas, large volume of polluted water, poor accessibility, and lack of financial supports. Advanced oxidation processes (AOPs) have been widely investigated as potential remedial options for contaminated water bodies of variety of settings, such as groundwater and waste discharges. This study presents a novel cost-effective approach for utilizing AOPs on improving quality of AMD-affected streams. Slow-release cylinders and pellets were created using polymeric binder and reagent salts that release strong oxidant and alkalinity upon dissolution in water. Results of column tests demonstrated that release durations were over 29 days and up to 100% iron removal was achieved within 20 minutes. Field-scale slow-release forms were manufactured and applied to an AMD site in southeast Ohio, USA for a 29-day demonstration study. Narrow channels were constructed for installation of slow-release forms and characterization of quality and flow of mine seeps and AMD stream during low subsurface flow periods. Results of field investigations suggest that the slow-release forms can be used to rapidly remove metals from AMD, as well as improve water parameters such as pH and minimize ecological impacts of remediation within the system in cost-effective manner.

 
How to reveal the present-day mechanism of the 600 km long Doruneh fault in eastern Iran ?
Authors: Khorrami Fateme , Walpersdorf Andrea , Mousavi Zahra , Pathier Erwan , Nankali Hamid , Sa'adat Reza , Walker Richard , Doin Marie-Pierre , Tavakoli Farokh , Djamour Yahya
Published: March 2020

The enigmatic 600 km long E-W trending left-lateral Doruneh fault in eastern Iran is certified to be active by its well preserved geomorphological features all along its trace, but it is lacking recent seismic activity that could be attributed to its motion. Instead, the high seismogenic potential of the study zone is highlighted by the two M=7 earthquakes on the left-lateral E-W trending Dasht-e-Bayaz fault just south of Doruneh, in 1968 and 1979. Therefore, it remains important to understand the role of the Doruneh fault in the kinematics of the Arabia-Eurasia collision that takes place inside Iran’s political boundaries.

Many different slip-rates have been estimated for the left-lateral motion of the Doruneh fault: 2.5 mm/yr by geomorphological marker offset dating, 1 mm/yr from preliminary GNSS measurements, and 5 mm/yr from a local InSAR study.  These rather local estimates on the 600 km long fault highlight either temporal or spatial variability of the Doruneh present-day behavior. The spatial variability of the fault slip is still badly constraint as the western half of the fault is located in the Great Kavir desert. The analysis of satellite radar images was supposed to provide good constraints on the inter-seismic deformation with a full spatial coverage of the fault, especially thanks to the favorable E-W orientation of the Doruneh fault and the arid Iranian climate. However, decorrelation due to sand dunes and unexpected large tropospheric noise prohibited precise results from a first large-scale ENVISAT study, yielding an upper limit of the slip rate of 4 mm/yr. The high resolution SENTINEL-1 constellation (operational since 2014) is predicted to provide constraints on inter-seismic velocities down to 2 mm/yr from 2020 on. In complement, a dense GNSS survey has been conducted in 2012 and 2018 on a temporary network of 18 sites around a large part of the fault. This network densifies and completes the 17 permanent GNSS stations in up to 200 km distance to the fault trace situated mostly in the eastern, more populated part of the fault.

In this work, we will point out our recent GNSS, InSAR and tectonic studies on the present-day characteristics of the Doruneh fault, to better understand the mechanism of this major fault in the kinematics of the Arabia-Eurasia collision, and to contribute to a better assessment of the seismic hazard in eastern Iran.
Seed Population Pre-Conditioning and Acceleration Observed by Parker Solar Probe
Authors: Niehof Jonathan , Schwadron Nathan ,   PSP/IS☉IS team
Published: March 2020

A series of solar energetic particle (SEP) events were observed at Parker Solar Probe (PSP) by the Integrated Science Investigation of the Sun (IS☉IS) during the period from April 18, 2019 through April 24, 2019. The PSP spacecraft was located near 0.48 au from the Sun on Parker spiral field lines that projected out to 1 au within ∼25° of near Earth spacecraft. These SEP events, though small compared to historically large SEP events, were amongst the largest observed thus far in the PSP mission and provide critical information about the space environment inside 1 au during SEP events. During this period the Sun released multiple coronal mass ejections (CMEs). One of these CMEs observed was initiated on April 20, 2019 at 01:25 UTC, and the interplanetary CME (ICME) propagated out and passed over the PSP spacecraft. Observations by the Electromagnetic Fields Investigation (FIELDS) show that the magnetic field structure was mostly radial throughout the passage of the compression region and the plasma that followed, indicating that PSP did not directly observe a flux rope internal to the ICME, consistent with the location of PSP on the flank of the ICME. Analysis using relativistic electrons observed near Earth by the Electron, Proton and Alpha Monitor (EPAM) on the Advanced Composition Explorer (ACE) demonstrates the presence of flare-accelerated seed populations during the events observed. The energy spectrum of the IS☉IS observed seed population below 1 MeV is consistent with the superposition of acceleration processes near the limit of plasma stability. IS☉IS observations reveal the compression and acceleration of seed populations during the passage of the ICME, which is likely a key part of the pre-acceleration process that occurs close to the Sun and pre-conditions the energetic particle acceleration process.
Turbulence and Plasma Inhomogeneity Observed by Swarm Constellation
Authors: De Michelis Paola , Consolini Giuseppe , Balasis Georgios , Bouffard Jerome ,   INTENS Team
Published: March 2020

The ionospheric environment is a complex system where dynamic phenomena, such as turbulence (fluid and magnetohydrodynamics) and plasma instabilities generally occur as a consequence of the coupling processes among solar wind, magnetosphere and ionosphere. It has been suggested that the turbulent character of the ionospheric plasma density also enters into the formation and dynamics of ionospheric inhomogeneities and irregularities, which essentially characterize the active equatorial, mid-latitude and polar regions. The ionospheric turbulence indirectly plays an important role also in the framework of space weather when due to the arrival of solar perturbations the plasma, the energetic particle distributions, the electric and magnetic fields within the magnetosphere and ionosphere are deeply modified thus paving the way for an increase in the ionospheric turbulence. Recent findings within the ESA funded project “Characterization of IoNospheric TurbulENce level by Swarm constellation (INTENS)” permitted us to investigate the role played by the turbulence on scales from hundreds of kilometers to a few kilometers in generating multi-scale plasma structures and inhomogeneities in the ionospheric environment at different latitudes. This presentation reports on the most promising results of the INTENS project regarding the investigation of turbulence and plasma conditions in the topside ionosphere using Swarm data.
Effects of crop residue on carbon dioxide, methane and nitrous oxide emissions on cultivated peat soils
Authors: Musarika Samuel , Jones Davey , Chadwick Dave , McNamara Niall , Evans Chris
Published: March 2020

Peatlands cover three percent of the global land surface. However, they store significant amounts of carbon (C), approximately 30%. Peatlands are drained to support agricultural production. It’s estimated that agriculture exploits approximately 20% of peatlands worldwide. The exploited peatlands are significant emitters of carbon dioxide (CO2) and nitrous oxide (N2O). In Europe, agriculture is the second largest contributor of greenhouse gas (GHG) emissions. In addition to GHG emissions, we are fast losing productive peatlands; it’s estimated by 2050, a third of productive peatlands will be lost. Loss of productive peatlands will affect productivity and food security.

To prolong use of peatlands, ploughing in of crop residue, either from the previous season or specially grown crop, is often considered a mitigation option. Nevertheless, there is concern that fresh organic matter (FOM) might accelerate decomposition of existing organic. This study assesses effects of FOM on the emissions of CO2, methane (CH4) and N2O in a cultivated peatland. A mesocosm experiment was carried out using intact cores with added FOM and manipulated water table (WT), -20 and -50 cm.

The results show there is an effect of both WT and FOM on emissions. CO2, CH4, and N2O emissions differ in the different WT treatments. The -20 cm cores produced more methane than the -50 cm.  It is evident that leaving crop residue and then ploughing it in does not have the desired effect as it led to increased emissions.
Green or grey? Integration of nature-based solutions for climate change adaptation in densifying cities
Authors: Erlwein Sabrina , Pauleit Stephan
Published: March 2020

Urban green and blue spaces such as water bodies, parks and street trees reduce outdoor temperatures and energy consumption of buildings through evaporative cooling and shading and are thus promoted as nature based solutions to enhance climate resilience. However, in growing cities, supply of urban green space often conflicts with increasing housing demand, resulting in dense neighbourhoods with lack of green. Therefore, the transdisciplinary project “Future green city” seeks to identify possibilities for balancing population growth and increasing living space demand with the development of nature-based solutions for climate change adaptation. In a transdisciplinary approach with the City of Munich, living labs are used to investigate how nature-based solutions can be integrated into spatial planning processes.

For the case of an urban redevelopment site with row buildings and a vast amount of greenery, eight densification scenarios were elaborated with city planners to derive planning guidelines for the further development of the area. The scenarios consider the effects of densification with additional floors and new buildings, the use of new building materials and energy efficiency standards, the construction of underground car parks and consequently a loss of green space to varying degrees. We are particularly interested in the interplay of densification and availability of green and its impact on indoor and outdoor thermal comfort, energy efficiency of buildings and their life cycle based emission balance. Microclimate modelling is employed to quantify and evaluate the impacts of densification on outdoor thermal conditions during heat days and the benefits of urban green in reducing heat stress.

First modelling results show that additional floors have less impact on human thermal comfort than loss of green space caused by the provision of required parking space. Though underground car parking avoids surface soil sealing, it leads to the removal of existing urban green and excludes the planting of large trees. Informal instruments such as mobility concepts can reduce space consumption by car parking. Moreover, urban redevelopment also bears the potential to increase climate resilience of the stock by targeted greening strategies. The potential is greater, the earlier climate change adaptation is considered as a topic in planning processes. Modelling helps to explore strength and weaknesses of different alternatives in early design stages.
Adding pieces to the atmosphere-biosphere feedback puzzle
Authors: Noe Steffen M. , Heikki Junninen , Mander Ülo , Hõrrak Urmas , Soosaar Kaido , Chen Xuemeng , Krasnova Alisa , Krasnov Dmitrii , Kollo Joonas , Komsaare Kaupo , Lipp Helina , Tamme Kalju , Kangur Ahto
Published: March 2020

The SMEAR Estonia station was established in 2012 as southernmost “Station for Ecosystem-Atmosphere Relations” in Northern Europe. The station provides continuous data since 2014 and has steadily increased the amount of measured variables. Measurements cover atmospheric gases, air ions and particulate matter, radiation and energy fluxes, forest ecosystem and soil related parameters. 
Located in the hemiboreal forest ecosystem at the southern edge of the boreal forest biome the forests are characterised  by a mix between coniferous and broadleaved species. The SMEAR Estonia station’s location near to an old growth forest, which is the oldest Estonian forest nature reserve established in 1924, allows for comparisons of atmosphere-biosphere related processes between unmanaged and managed forests. The application of continuous multi-scale data allows us to see first trends of hemiboreal ecosystem-atmosphere interactions in relation to natural and man made disturbances and climatic drivers.
Here, we report and present our available multi-scale data and research results. Our focus lies on the heterogeneity and the dynamics of atmosphere-biosphere exchange processes and feedbacks in the footprint of the SMEAR Estonia station.
Testing continuity of the Hadean-Eoarchean geodynamo with zircon paleomagnetism
Authors: Tarduno John , Cottrell Rory , Hofmann Axel
Published: March 2020

Understanding the pre-Paleoarchean geodynamo is arguably the greatest technical challenge for paleomagnetism: only silicate crystals bearing magnetic inclusions now found in younger sedimentary units may have escaped the metamorphism that otherwise excludes extant Paleoarchean to Hadean whole rocks from consideration. The recent optical and electron microscope documentation of primary magnetite inclusions in Jack Hills zircons (Tarduno et al., PNAS, 2020), previously predicted by paleomagnetic unblocking temperatures, together with microconglomerate test results, Pb-Pb radiometric age data and Li-diffusion constraints, support a geodynamo as old as 4.2 billion-years-old. While the available record is to first-order consistent with a continuous geodynamo since the Hadean, there are several 50-100 m.y. gaps in the record. Herein we examine these gaps and further test the paleointensity history derived from Jack Hills zircons through study of Paleoarchean and older detrital zircons of the Singhbum craton of eastern India. Preliminary paleomagnetic and paleointensity data suggest the presence of a primary magnetism, magnetite inclusion carriers and field strengths similar to those of the Jack Hills record.
Effective rheology of a two-phase subduction shear zone calculated by numerical simple shear experiments
Authors: Ioannidi Paraskevi Io , Le Pourhiet Laetitia , Oncken Onno , Agard Philippe , Angiboust Samuel
Published: March 2020

The physical nature and the rheology of a subduction shear zone play an important role in the deformation and the degree of locking along its interface with the upper plate. Inspired from exhumed subduction shear zones that exhibit block-in-matrix characteristics (mélanges), we create synthetic models with different proportions of strong clasts within a weak matrix and compare them to natural mélange outcrops. Using 2D Finite Element visco-plastic numerical simulations and simple shear kinematic conditions, we determine the effective rheological parameters of such a two-phase medium, comprising blocks of basalt embedded within a wet quartzitic matrix. We treat our models and their structures as scale-independent and self-similar and upscale published field geometries to km-scale models, compatible with large-scale far-field observations. Exhumed subduction mélanges suggest that deformation is mainly taken up by dissolution-precipitation creep. However, such flow laws are neither well-established yet experimentally nor of ample use in numerical modelling studies. In order to make our results comparable to and usable by numerical studies, we assume dislocation creep as the governing flow law for both basalt and wet quartz and by using different pressures, temperatures and strain rates we provide effective rheological estimates for a natural subduction interface. Our results suggest that the block-in-matrix ratio affects deformation and strain localization, with the effective dislocation creep parameters varying between the values of the strong and the weak phase, in cases where deformation of both materials is purely viscous. As the contribution of brittle deformation of the strong blocks increases, however, the value of the stress exponent, n, can exceed that of the purely strong phase.
A Venus-like atmosphere on the early Earth from magma ocean outgassing
Authors: Sossi Paolo , Burnham Antony , Badro James , Lanzirotti Antonio , Newville Matt , O'Neill Hugh
Published: March 2020

Outgassing of an early magma ocean on Earth plays a dominant role in determining the composition of its secondary atmosphere, and hence bears on the potential for the emergence of life. The stability of gaseous species in such an atmosphere reflects the redox state of the magma ocean. However, the relationship between oxygen fugacity (fO2) and the oxidation state of the most abundant polyvalent element, Fe, in likely magma ocean compositions is poorly constrained. Here we determine Fe2+/Fe3+ ratios as a function of fO2 in peridotite liquids, experimentally synthesised by aerodynamic laser levitation at 1 bar and 2173 K. We show that a magma ocean with Fe3+/∑Fe akin to that of contemporary upper mantle peridotite (0.037) would have had fO2 0.5 log units higher than the Fe-“FeO” equilibrium. At this relative fO2, a neutral CO2-H2O-dominated atmosphere of ~ 150 bar would have developed on the early Earth, taking into account the solubilities of the major volatiles, H, C, N and O in the magma ocean. Upon cooling, the Earth’s prebiotic atmosphere was likely comprised of CO2-N2, in proportions and at pressures akin to that on presently found on Venus.
Using Earth Observations to engender a social-ecological systems perspective on rural livelihoods and wellbeing.
Authors: Hargreaves Peter , Watmough Gary
Published: March 2020

An estimated 70% of the world’s poorest people live in rural spaces. There is a consistent differentiation between rural and urban contexts, where the former are typically characterised by weak infrastructure, limited services and social marginalisation. At the same time, the world’s poorest people are most vulnerable to global change impacts. Historic pathways to measuring and achieving poverty reduction must be adapted for an era of increasingly dynamic change, where spatio-temporal blind spots preclude a comprehensive understanding of poverty and its manifestation in rural developing contexts. To catalyse an effective poverty eradication narrative, we require a characterisation of the spatio-temporal anatomy of poverty metrics. To achieve this, researchers and practitioners must develop tools and mobilise data sources that enable the detection and visualisation of economic and social dimensions of rural spaces at finer temporal and spatial scales than is currently practised. This can only be realised by integrating new technologies and non-traditional sources of data alongside conventional data to engender a novel policy landscape.

Cue Earth Observation: the only medium through which data can be gathered that is global in its coverage but also available across multiple temporal and spatial scales. Earth Observation (EO) data (collected from satellite, airborne and in-situ remote sensors) have a demonstrable capacity to inform, update, situate and provide the necessary context to design evidence-based policy for sustainable development. This is particularly important for the Sustainable Development Goals (SDGs) because the nested indicators are based on data that can be visualised, and many have a definitive geospatial component, which can improve national statistics reporting.

In this review, we present a rubric for integrating EO and geospatial data into rural poverty analysis. This aims to provide a foundation from which researchers at the interface of social-ecological systems can unlock new capabilities for measuring economic, environmental and social conditions at the requisite scales and frequency for poverty reporting and also for broader livelihoods and development research.  We review satellite applications and explore the development of EO methodologies for investigating social-ecological conditions as indirect proxies of rural wellbeing. This is nested within the broader sustainable development agenda (in particular the SDGs) and aims to set out what our capabilities are and where research should be focused in the near-term. In short, elucidating to a broad audience what the integration of EO can achieve and how developing social-ecological metrics from EO data can improve evidence-based policymaking.

Key words: Earth Observation; Poverty; Livelihoods; Sustainable Development Goals; Remote Sensing