bluuebunny/crossref_metadata_2025 huggingface dataset:
Nuisance Flooding in Coastal Communities: Real-time Modeling and Decision Support to Improve Transportation Infrastructure Resilience
Authors: Goodall Jonathan L. , Behl Madhur , Bowes Benjamin , Campbell Brad , Chen Alex , Chen T. Donna , Sadler Jeffrey , Spencer Kyle , Gorman Michael , Praharaj Shraddha , Shen Yawen , Zahura Faria Tuz , Zeng Luwei
Published: March 2020

Nuisance flooding, which is repetitive flooding caused by both tidal and rainfall-driven events, is increasing in frequency and severity for many coastal communities. As climate change causes sea level rise and more frequent and intense storm events, these nuisance flooding events are producing significant disruptions and impacts to coastal communities. The objective of this study is to improve modeling and decision support activities around nuisance flooding and, in particular, its impact on transportation infrastructure. Our study region and partner in the research is the City of Norfolk, Virginia, USA. Norfolk is home to the largest Navy base in the world, the second busiest port on the United States East Coast, and is the second most populous city in Virginia. It is also one of 100 Rockefeller Resilient Cities in the world, committed to taking progressive aims at combating nuisance flooding. Using real-time observational networks, crowdsourced data, physics-based and machine learning modeling approaches, model predictive control, and economic and social science methods, we are exploring ways to better understand and mitigate the impacts of street-scale flooding. Our research is showing how real-time control of stormwater infrastructure systems can help to improve the resilience of these systems during nuisance flooding events by strategically holding back rainfall runoff and preventing tidally driven stormwater backups. We are also showing physics-based and machine-learning methods can be combined for real-time decision support and how reputation system approaches can be used to measure trust in crowdsourced rainfall datasets. This presentation will provide an overview of these and related activities, each aimed at the common goal of leveraging real-time data from a variety of sources, innovative modeling techniques, and community-driven decision making to improve community resilience to nuisance flooding.
Understanding the effects of dynamic sediment inputs on the prediction of coastal wetland evolution
Authors: Breda Angelo , Saco Patricia , Rodriguez José , Sandi-Rojas Steven
Published: March 2020

Over the last two decades, there have been important advances in eco-geomorphological modelling of coastal wetlands to predict their evolution. Different features have been incorporated into models, bust most applications still assume a constant or static sediment concentration as input representing average conditions. Such imposition is related to many constraints in obtaining a time series of total suspended matter (TSM). However, with the increasing availability of multispectral satellite products and the development of artificial intelligence algorithms, TSM data can be estimated through remote sensing. This work aims to assess the effect of using a dynamic time varying condition for the TSM input when simulating eco-geomorphological processes. We implemented a modelling framework adapted to conditions found in SE Australian estuaries, which includes hydrodynamic and sediment transport processes. Many scenarios where simulated encompassing different levels of average TSM and water levels. Our findings suggest that under low water levels and low sediment concentration, a static TSM input results in more accretion than a dynamic input. However, at higher levels and concentration, the dynamic input led to higher accretion. Predictions of vegetation distribution were not particularly sensitive to changes in TSM over time.
Driving mechanisms of coastal cliff retreat in flysch deposits on the eastern Adriatic coast
Authors: Vlastelica Goran , Pikelj Kristina , Kordić Branko
Published: March 2020

Cliffs formed in soft rocks are rare coastal forms along the Croatian eastern Adriatic and most exposed to natural erosional processes. The rare example of such cliff affected by anthropogenic activities was developed in marl-dominated flysch in the Split urban zone. Due to the panoramic view cliff-top area is being massively occupied since the 1980ies mostly for the tourism industry and urban development. In spite of increased pressure, little attention has been given to the cliff stability. Ongoing cliff erosion seriously endangers both, coastal infrastructure on the cliff-top, as well as at the narrow shore platform used as a recreational beach area, demanding the urgent development of erosion management plan. In order to do so, fundamental knowledge is needed to understand the cliff erosion driving mechanisms.

The non-vegetated cliff face was scanned 11 times by terrestrial laser scanner during the 6-year period (2012-2018). Four representative profiles along the study area were compared on precisely georeferenced point clouds. Additionally, a close examination of the cliff-top, cliff face and shore platform was carried out over 15 times during various seasons and weather conditions in order to recognize erosional processes involved. Cliff retreat rates obtained from our monitoring ranged between 3 and 18 cm/y. Extreme erosion rates of 25-34 cm/y occurred during the 2014/2015 and 2017/2018 monitoring period. Both extremes occurred after autumn and spring high precipitation periods. A causal link between intensive rain periods and erosion was further observed after two landslides during spring 2018. Furthermore, many gullies caused by surface runoff were carved after heavy rains. At the same time, increased amount of groundwater caused seepage along structural discontinuities, inducing surface erosion below the seeping line. All observed erosional processes occasionally lead to the occasional formation of marly talus cones at the cliff toe. Their duration depends on wave climate, and are being gradually removed by waves.

Obtained results showed that monitored coastal cliff is predominantly subjected to various processes of surface erosion related with high precipitation, while wave abrasion is of subordinate role. Predominant marl lithology is likely to cause further surface mechanical erosion, highlighting the need for erosion management to be developed.
The eWaterCycle platform for FAIR and Open Hydrological Modeling
Authors: Drost Niels , Camphuijsen Jaro , Hut Rolf , Van De Giesen Nick , van Werkhoven Ben , Aerts Jerom P.M. , Pelupessy Inti , Weel Berend , Verhoeven Stefan , van Haren Ronald , Hutton Eric , van Meersbergen Maarten , Alidoost Fakhereh , van den Oord Gijs , Dzigan Yifat , Andela Bouwe , Kalverla Peter
Published: March 2020

The eWaterCycle platform is a fully Open-Source platform built specifically to advance the state of FAIR and Open Science in Hydrological Modeling.

eWaterCycle builds on web technology, notebooks and containers to offer an integrated modelling experimentation environment for scientists. It allows scientists to run any supported hydrological model with ease, including setup and preprocessing of all data required. 

eWaterCycle comes with an easy to use explorer, so the user can get started with the system in minutes, and uniquely lets the user generate a hydrological model notebook based on their preferences.

The eWaterCycle platform uses Jupyter as the main interface for scientific work to ensure maximum flexibility. Common datasets such as ERA-Interim and ERA-5 forcing data and observations for verification of model output quality are available for usage by the models.

To make the system capable of running any hydrological model we use docker containers coupled through gRPC. This allows us to support models in a multitude of languages, and provide fully reproducible model experiments.

Based on experiences during a FAIR Hydrological Modeling workshop in Leiden in April 2019 we have created a common pre-processing system for Hydrological modeling, based on technology from the climate sciences, in particular ESMValTool and Iris. This pre-processing pipeline can create input for a number of Hydrological models directly from the source dataset such as ERA-Interim in a fully transparent and reproducible manner.

During this pico presentation, we will explain how this platform supports creating reproducible results in an easy to use fashion.
Geomorphic evidence for active, co-seismic slip along a low-angle normal fault: Panamint Valley, California
Authors: Kirby Eric , Sethanant Israporn (Grace) , Gosse John , McDonald Eric , Walker J Doug
Published: March 2020

The mechanical feasibility of co-seismic displacement along low-angle normal fault systems remains an outstanding problem in tectonics.  In the southwestern Basin and Range of North America, large magnitude extension during Miocene – Pliocene time was accommodated along a regionally extensive system of low-angle detachment faults.  Whether these faults remain active today and, if so, whether they rupture during large earthquakes are questions central to understanding the geodynamics of distributed lithospheric deformation and associated seismic hazard.  Here we evaluate the geometric and kinematic relationships of fault scarps developed in Pleistocene – Holocene alluvial and lacustrine deposits with low-angle detachment faults observed along the western flank of the Panamint Range, in eastern California.  We combine analysis of high-resolution topography generated from airborne LiDAR and photogrammetry with a detailed chronology of alluvial fan surfaces and a calibrated soil chronosequence to characterize the recent activity of the fault system.  The range-front fault system is coincident with a low-angle (15-20°), curviplanar detachment fault that is linked to strike-slip faults at its southern and northern ends.  Fanglomerate deposits in the hanging wall of the detachment are juxtaposed with brecciated bedrock in the footwall across a narrow fault surface marked by clay-rich gouge.  Isochron burial dating of the fanglomerate using the 26Al and 10Be requires displacement in the past ~800 ka.  The degree of soil development in younger alluvial deposits in direct fault contact with the footwall block suggest displacement along the main detachment in the past as ~80-100 ka.  The geometry of recent fault scarps in Holocene alluvium mimic range-scale variations in strike of the curviplanar detachment fault, suggesting that scarps merge with the detachment at depth.  Moreover, fault kinematics inferred from displaced debris-flow levees and from fault striae on the bedrock range front are consistent with slip on a low-angle detachment system beneath the valley.  Finally, paleoseismic results from a trench at the southern end of the fault system suggest 3-4 surface ruptures during past ~4-5 ka, the most recent of which (MRE) occurred ~330-485 cal yr BP.  Scarps related to the MRE can be traced for at least ~50 km northward along the range front and imply surface displacements of 2-4 meters during this event.  Thus, we conclude that ongoing dextral shear along the margin of the Basin and Range is, in part, accommodated by co-seismic slip along low-angle detachment faults in Panamint Valley.  Our results have important implications for the interaction of fault networks and seismic hazard in the region.
solar system
Authors: Tsirogianni Vasiliki
Published: March 2020

                                              Solar System

 

   The beauty and the vastness of science remains an astonishing lesson for all. As a teacher I have consciously chosen the topic of our solar system for my class (1st grade, 6-7 age ) in order to boost their willingness to explore fascinating questions regarding it. Very early, every morning, they look up at the sky and they point at the moon. They wonder how it is like. This topic gives incentives to students to learn more about life. It helps them appreciate the Earth. It gives them the motivation to preserve and respect our natural resources.

Young students certainly will get to know the planets, their order, size and more, but my main target is to enhance their curiosity about Knowledge. We will learn new terms that are linked to the solar system through interactive, interesting and funny activities to boost comprehension. Using a combination of illustrations, books, videos, worksheets and crafts is an excellent way to introduce children in simple concept and lessons. Then common activities will follow including coloring the planets, putting them in order and creating a model of the solar system.

There are a number of subjects worth exploring (planets, moon, satellites, spacecrafts, telescopes, stars, Earth, sun). My students will form groups and each group will choose the subject that excites it and focus on it.

I have already scheduled a visit to the National Observatory of Athens which will mark the end of this project.

 I would like to finish this abstract by paraphrasing Neil Armstrong: "one small incentive for a student, one giant step for the future scientists ".

 
Transformation of Atlantic Water in the Barents Sea in winter: overview of “Transarctika-2019” cruise results
Authors: Ivanov Vladimir , Frolov Ivan , Filchuk Kirill
Published: March 2020

In the recent few years the topic of accelerated sea ice loss, and related changes in the vertical structure of water masses in the East-Atlantic sector of the Arctic Ocean, including the Barents Sea and the western part of the Nansen Basin, has been in the foci of multiple studies. This region even earned the name the “Arctic warming hotspot”, due to the extreme retreat of sea ice and clear signs of change in the vertical hydrographic structure from the Arctic type to the sub-Arctic one. A gradual increase in temperature and salinity in this area has been observed since the mid-2000s. This trend is hypothetically associated with a general decrease in the volume of sea ice in the Arctic Ocean, which leads to a decrease of ice import in the Barents Sea, salinization, weakening of density stratification, intensification of vertical mixing and an increase of heat and salt fluxes from the deep to the upper mixed layer. The result of such changes is a further reduction of sea ice, i.e. implementation of positive feedback, which is conventionally refereed as the “atlantification. Due to the fact that the Barents Sea is a relatively shallow basin, the process of atlantification might develop here much faster than in the deep Nansen Basin. Thus, theoretically, the hydrographic regime in the northern part of the Barents Sea may rapidly transform to a “Nordic Seas – wise”, a characteristic feature of which is the year-round absence of the ice cover with debatable consequences for the climate and ecosystem of the region and adjacent land areas. Due to the obvious reasons, historical observations in the Barents Sea mostly cover the summer season. Here we present a rare oceanographic data, collected during the late winter - early spring in 2019. Measurements were occupied at four sequential oceanographic surveys from the boundary between the Norwegian Sea and the Barents Sea – the so called Barents Sea opening to the boundary between the Barents Sea and the Kara Sea. Completed hydrological sections allowed us to estimate the contribution of the winter processes in the Atlantic Water transformation at the end of the winter season. Characteristic feature of the observed transformation is the homogenization of the near-to-bottom part of the water column with remaining stratification in the upper part. A probable explanation of such changes is the dominance of shelf convection and cascading of dense water over the open sea convection. In this case, complete homogenization of the water column does not occur, since convection in the open sea is impeded by salinity and density stratification, which is maintained by melting of the imported sea ice in the relatively warm water. The study was supported by RFBR grant # 18-05-60083.
Development and investigation of a deep learning based method for TEC map completion
Authors: Jin Mingwu , Pan Yang , Zhang Shunrong , Deng Yue
Published: March 2020

Because of the limited coverage of receiver stations, current measurements of Total Electron Content (TEC) by ground-based GNSS receivers are not complete with large portions of data gaps. The processing to obtain complete TEC maps for space science research is time consuming and needs the collaboration of five International GNSS Service (IGS) Ionosphere Associate Analysis Centers (IAACs) to use different data processing and filling algorithms and to consolidate their results into final IGS completed TEC maps. In this work, we developed a Deep Convolutional Generative Adversarial Network (DCGAN) and Poisson blending model (DCGAN-PB) to learn IGS completion process for automatic completion of TEC maps. Using 10-fold cross validation of 20-year IGS TEC data, DCGAN-PB achieves the average root mean squared error (RMSE) about 4 absolute TEC units (TECu) of the high solar activity years and around 2 TECu for low solar activity years, which is about 50% reduction of RMSE for recovered TEC values compared to two conventional single-image inpainting methods. The developed DCGAN-PB model can lead to an efficient automatic completion tool for TEC maps.
Towards fast large-scale flood simulations using 2D Shallow water modelling with depth-dependant porosity
Authors: Ayoub Vita , Delenne Carole , Matgen Patrick , Finaud-Guyot Pascal , Hostache Renaud
Published: March 2020

In hydrodynamic modelling, the mesh resolution has a strong impact on run time and result accuracy. Coarser meshes allow faster simulations but often at the cost of accuracy. Conversely, finer meshes offer a better description of complex geometries but require much longer computational time, which makes their use at a large scale challenging. In this context, we aim to assess the potential of a two-dimensional shallow water model with depth-dependant porosity (SW2D-DDP) for flood simulations at a large scale. This modelling approach relies on nesting a sub-grid mesh containing high-resolution topographic and bathymetric data within each computational cell via a so-called depth-dependant storage porosity. It enables therefore faster simulations on rather coarse grids while preserving small-scale topography information. The July 2007 flood event in the Severn River basin (UK) is used as a test case, for which hydrometric measurements and spatial data are available for evaluation. A sensitivity analysis is carried out to investigate the porosity influence on the model performance in comparison with other classical parameters such as boundary conditions.
Geomorphological analysis of a sub-Antarctic valley under deglaciation: the Guynemer basin, Kerguelen Archipelago (49°S), Southern Indian Ocean
Authors: Deline Philip , Linge Henriette , Ravanel Ludovic , Bakke Jostein , Arnaud Fabien , Giguet-Covex Charline , Støren Eivind
Published: March 2020

Located in the southern part of the Indian Ocean (49°S), the Kerguelen Archipelago is the largest of the sub-Antarctic islands with an area of ​​around 7,200 km2. With a volcanic origin, its main island Grande Terre is partly covered by the Cook ice Cap which rises above 1000 m a.s.l. Numerous glaciers flow towards deep fjords especially from the ice cap. Their total surface area decreased by 21 % between 1963 and 2001, from 703 to 552 km2 [1]. This high retreat rate was associated with an increase in air temperature and a decrease in precipitation potentially associated with a modification of the westerlies' regime. The archipelago has so far been the subject of very little geomorphological work, while thirty cosmogenic nuclide dates distributed on the archipelago allow a first insight in the deglaciation with ages between 41.9 ± 4.4 and 0.7 ± 0.37 ka [2].

Within the PALAS expedition (PAleoclimate from LAke Sediments) carried out in November and December 2019 on several lakes located between the ice cap and the Peninsula of the Société de la Géographie, we mapped the geomorphology of several valleys. Here we present the mapping results and analysis of the Guynemer basin located downstream the Guynemer Peak (1088 m a.s.l.). Located c. 10 km north of the Cook Ice Cap, its slopes mainly consist of frost-shattered debris interspersed with rocky escarpments, but the basin still contains a small glacier (<1.5 km2) at the foot of the east face of the peak. This face has several small hanging glaciers, one of which showing signs of destabilization. An upper Guynemer Lake resulting from the glacial over-deepening (0.5 km2; 245 m a.s.l.) is separated from the lower Guynemer Lake (1.5 km2; 121 m a.s.l.) by a rock step, a gorge and a wide delta incised by several channels. The mapped sector has many glacial inheritances, from the cirque which contains the upper lake to a frontal moraine that is partly damming the lower lake. Several dozens of morainic ridges have been recognized, corresponding at least to 6 or 7 main stages, from possibly early Holocene or Lateglacial to the 1960s. Surface exposure dating of moraines and erratic boulders in the coming months will supply a detailed chronology of the glacier fluctuations.

 

[1] Berthier et al. (2009). Journal of Geophysical Research - Earth Surface, 114: F3.

[2] Jomelli et al. (2018). Quaternary Science Reviews, 183: 110-123.
The Surface of Tree Tissues as Source of Extractable Ice Nucleating Macromolecules during Rainfall Events
Authors: Grothe Hinrich , Seifried Teresa M. , Bieber Paul , Felgitsch Laura
Published: March 2020

Several biological particles are able to trigger heterogeneous ice nucleation at subzero temperatures above -38°C. Many plants species such as winter rye [1], certain berries [2], pines and birches [3, 4] are known to contain biological ice-nucleating particles (BINPs) or rather ice-nucleating macromolecules (INMs). However, the influence of these BINPs on atmospheric processes including cloud glaciation and precipitation formation, as well as transport mechanisms of BINPs from the land surface into the atmosphere remain uncertain. If those INMs are easily available on the surfaces of a plant, they could be washed down by heavy rain events and could add an important new source for BINPs in the atmosphere, which has not received enough attention in the past.

In this study, we have focused on alpine trees, which form INMs extractable from their surfaces. We examined ice nucleation activity of samples from different birches (Betula pendula) and pines (Pinus sylvestris) growing in the Alps in Austria, Europe. Filtered aqueous extracts of leaves, needles, bark and wood were analyzed in the laboratory in terms of heterogeneous ice nucleation using VODCA (Vienna Optical Droplet Crystallization Analyzer), a cryo-microscope  for  emulsion  samples.  All plant tissues contained INMs in the submicron size range. Furthermore, we conducted a field experiment, in which we investigated the possibility of INMs to be released from the surface of the trees into the atmosphere during rain showers.

[1] Brush, R.A., M. Griffith, and A. Mlynarz, Characterization and Quantification of Intrinsic Ice Nucleators in Winter Rye (Secale cereale) Leaves. Plant Physiol, 1994. 104(2): p. 725-735.

[2] Felgitsch, L., et al., Heterogeneous Freezing of Liquid Suspensions Including Juices and Extracts from Berries and Leaves from Perennial Plants. Atmosphere, 2019. 10(1): p. 1-22.

 [3] Pomeroy, M.K., D. Siminovitch, and F. Wightman, Seasonal biochemical changes in the living bark and needles of red pine (Pinus resinosa) in relation to adaptation to freezing. Canadian Journal of Botany, 1970. 48(5): p. 953-967.

[4] Felgitsch, L., et al., Birch leaves and branches as a source of ice-nucleating macromolecules. Atmospheric Chemistry and Physics, 2018. 18(21): p. 16063-16079.

[5] Pummer, B.G., et al., Ice nucleation by water-soluble macromolecules. Atmospheric Chemistry and Physics, 2015. 15(8): p. 4077-4091.
Ingredients of German flood events
Authors: Merz Ralf , Tarasova Larisa , Basso Stefano
Published: March 2020

Floods can be caused by a large variety of different processes, such as short, but intense rainfall bursts, long rainfall events, which are wetting up substantial parts of the catchment, or rain on snow cover or frozen soils. Although there is a plethora on studies analysing or modelling rainfall-runoff processes, it is still not well understood, what rainfall and runoff generation conditions are needed to generate flood runoff and how these characteristics vary between catchments. In this databased approach we decipher the ingredients of flood events occurred in 161 catchments across Germany. For each catchment rainfall-runoff events are separated from observed time series for the period 1950-2013, resulting in about 170,000 single events. A peak-over-threshold approach is used to select flood events out of these runoff events. For each event, spatially and temporally distributed rainfall and runoff generation characteristics, such as snow cover and soil moisture, as well as their interaction are derived. Then we decipher those event characteristics controlling flood event occurrence by using machine learning techniques.

On average, the most important event characteristic controlling flood occurrence in Germany is, as expected, event rainfall volume, followed by the overlap of rainfall and soil moisture and the extent of wet areas in the catchment (area with high soil moisture content). Rainfall intensity is another important characteristic. However, a large variability in its importance is noticeable between dryer catchments where short rainfall floods occur regularly and wetter catchments, where rainfall intensity might be less important for flood generation. To analyse the regional variability of flood ingredients, we cluster the catchments according to similarity in their flood controlling event characteristics and test how good the flood occurrence can be predicted from regionalised event characteristics. Finally, we analyse the regional variability of the flood ingredients in the light of climate and landscape catchment characteristics.
Detection of tsunami induced ionospheric perturbation with ship-based GNSS measurements: 2010 Maule tsunami case study
Authors: Ravanelli Michela , Foster James
Published: March 2020

The VARION (Variometric Approach for Real-Time Ionosphere Observation) algorithm has been successfully applied to TIDs (Travelling ionospheric disturbances) detection in several real-time scenarios [1, 2]. VARION, thus, estimates sTEC (slant total electron content) variations starting from the single time differences of geometry-free combinations of GNSS carrier-phase measurements. This feature makes VARION suitable to also leverage GNSS observations coming from moving receivers such as ship-based GNSS receivers: the receiver motion does not affect the sTEC estimation process.

The aim of this work is to use the observations coming from two GNSS receivers installed on a ship moving near Kauai Island in the Hawaiian archipelago to detect the TIDs connected to the 2010 Maule earthquake and tsunami [3]. Indeed, this earthquake triggered a tsunami that affected all the Pacific region and that reached the Hawaiian islands after about 15 hours. All our analysis was carried out in post-processing, but simulated a real-time scenario: only the data available in real time were used.

In order to get a reference, the ship-based sTEC variations were compared with the ones coming from GNSS permanent stations situated in the Hawaiian Islands. In particular, if we considered the same satellite, the same TID is detected by both ship and ground receivers. As expected, the ship-based  sTEC variations are a little bit noisier since they are coming from a kinematic platform.

Hence, the results, although preliminary, are very encouraging: the same TIDs is detected both from the sea (ships) and land (permanent receivers).  Therefore, the VARION algorithm is also able to leverage observations coming from ship-based GNSS receivers to detect TIDs in real-time.

In conclusion, we firmly believe that the application of VARION to observation coming from ship-based GNSS receivers could really represent a real-time and cost-effective tool to enhance tsunami early warning systems, without requiring the installation of complex infrastructures in open sea.

References

[1] Giorgio Savastano, Attila Komjathy, Olga Verkhoglyadova, Augusto Mazzoni, Mattia Crespi, Yong Wei, and Anthony J Mannucci, “Real-time detection of tsunami ionospheric disturbances with a stand-alone gnss receiver: A preliminary feasibility demonstration, ”Scientific reports, vol. 7, pp. 46607, 2017.

[2] Giorgio Savastano, Attila Komjathy, Esayas Shume, Panagiotis Vergados, Michela Ravanelli, Olga Verkhoglyadova, Xing Meng, and Mattia Crespi, “Advantages of geostationary satellites for ionospheric anomaly studies: Ionospheric plasma depletion following a rocket launch,”Remote Sensing, vol. 11, no. 14, pp. 1734, 2019

[3] https://earthquake.usgs.gov/earthquakes/eventpage/official20100227063411530_30/executive
CLASSnmat: a new dataset of Night Marine Air Temperature back to 1880
Authors: Cornes Richard , Kent Elizabeth , Berry David , Kennedy John
Published: March 2020

We describe the construction of a new global dataset of Night Marine Air Temperature (NMAT), which provides monthly 5-degree values of NMAT back to 1880 with associated uncertainty estimates. The new dataset (CLASSnmat) builds on the HadNMAT2 dataset, which was released in 2013. CLASSnmat uses the ship-based NMAT values from the International Comprehensive Ocean-Atmosphere Data Set (ICOADS Release 3). However, a new method is used in CLASSnmat to remove duplicated values from the observations, and to infill missing ship identifiers. In addition, a revised method of correcting the warm-bias that occurs in the data during World 2 is applied, which allows the retention of more data than in HadNMAT2. As with its predecessor, the NMAT data in CLASSnmat are not interpolated to grid-cells devoid of observations, but a revised gridding method is used which improves the propagation of uncertainty from the individual measurements through to the gridded values. CLASSnmat is released with NMAT values corrected to 2, 10 and 20m height to allow direct comparison against other measures of temperature, e.g. land-based observations or reanalysis temperature values.
Imaging the poro-elastic properties of glacier beds using ambient seismic noise monitoring : application to Whillans ice stream, Antarctica
Authors: Mordret Aurélien , Guerin Gauthier , Rivet Diane , Lipovsky Brad , Minchew Brent
Published: March 2020

Part of the movement that occurs on all glaciers in Antarctica is a continuous and stable movement that unloads the ice into the sea. The Whillans Ice Plain (WIP) is a portion of the Whillans ice stream that measures 8000 km² for an ice thickness of 800 meters. This glacier has a unique characteristic of moving thanks to tidally modulated stick-slip events twice a day. The slip speed varies laterally across the glacier.  We measured surface wave velocity variations computed from ambient seismic noise cross-correlation. The cross-correlations make it possible to monitor temporally and spatially the seismic velocities at the bed of the glacier, associated with changes in poro-elastic parameters and frictional properties of the glacial till. We averaged our observations for the 78 stick-slip events of our dataset and managed to achieve a 5 min temporal resolution along the 45 min long slip events. The results show a decrease in velocity of about 9% of the S-wave velocity in the subglacial sediment layer about 30 minutes after the initiation of the slip. This velocity drop mainly affects the central part of the glacier. A 10% increase in porosity could induce this velocity decrease due to dilatancy. Dilatant strengthening results from this porosity increase, which in turn keeps the glacier in a slow-sliding regime. The high rate of seismic cycles on such a large scale makes the Whillans ice stream a unique laboratory to study transient aseismic slips in glacial context but also in active tectonic faults one. 
Augmenting the multiscale hydrologic modeling system with adequate vegetation dynamics for improved representation of coupled water and carbon cycles
Authors: Bahrami Bahar , Kumar Rohini , Thober Stephan , Rebmann Corinna , Fischer Rico , Samaniego Luis , Kleidon-Hildebrandt Anke , Attinger Sabine
Published: March 2020

As climate is changing, future functionality and resilience of terrestrial ecosystems are expected to change in numerous ways. However, these projected changes remain uncertain. One of the major sources of uncertainty is the representation of vegetation dynamics which directly respond to increased temperature and ambient CO2 concentrations and thereby alter transpiration. Many of the existing hydrologic models representing components of the water cycle have a very simplified representation of vegetation dynamics that are not able to represent this link.  In this study we aim to augment the existing mesoscale Hydrologic Model (mHM) with a low complexity dynamic vegetation model (DVM). This will provide the model with improved capabilities to represent the coupled water and carbon fluxes. Our analyses focus on representing the vegetation (i.e. biomass growth) including fluxes such as gross and net primary productivity and their inter-linkages to water storage and fluxes (e.g., soil moisture and evapotranspiration) across biomes (e.g., grasslands). These inter-linkages, which are spatially and temporally variable and scale-related, are crucial for adequately representing the coupled water and carbon cycle. For example, the adequate representation of soil moisture is essential to capture the mechanistic response of plant productivity to changes in soil moisture; and vice versa especially under extreme environmental conditions. In this presentation, we will discuss the simplified structure of the DVM based on a Light Use Efficiency (LUE) model concept and couple the model components to the mHM. Furthermore, the coupled simulation results of different water and carbon fluxes will be presented for a test region in Central Germany.   
Detection and estimation of the Slichter mode based on the data of the IGETS superconducting gravimeters network using the asymptotically optimal algorithm
Authors: Milyukov Vadim , Vinogradov Mikhail , Mironov Alexey , Myasnikov Andrey
Published: March 2020

Traditionally, searching the Slichter mode (the longest-period mode of the Earth's free oscillations 1S1) is based on the data of the superconducting gravimeters of the international GGP network. Currently this network is included in the International Geodynamics and Earth Tide Service (IGETS).

The sensitivity limit of the best superconducting gravimeters is about 1 nGal and not sufficient for direct observation of the Slichter mode even after the significant earthquakes. To reduce the detection threshold, the researchers used the “stacking” procedure — an joint data processing of the several instruments, but the different sensitivity level of the gravimeters prevents the achievement of maximum efficiency.

We have developed an asymptotically optimal algorithm based on the maximum likelihood method that takes into account the features of the Slichter mode and seismic noise. An important feature of the algorithm is its ability to evaluate the splitting parameter b which determines the distance between the side singlets of the triplet, simultaneously with the mode period T. The use of a non-linear inertial converter allows to take into account the non-Gaussian noise of real data. The use of the Neumann-Pearson criterion makes also possible to determine confidence level of detection: the false alarm probability and the correct detection probability, depending on the signal-to-noise ratio).

The algorithm was tested on synthetic data. A computer experiment has shown that the algorithm can detect the Slichter mode for a signal-to-noise ratio of 10-4. The algorithm was used to search the Slichter mode after the largest earthquakes based on the data of the IGETS network.

The results of the analysis are reported.

This work is supported by the Russian Foundation for Basic Research under Grant No Grant No 19-05-00341.
Water Mixing and Circulation within the South Atlantic Basin Constrained by Seismic Reflection Images
Authors: Wei Jingxuan , Reece Robert , Fortin Will , Acquisto Tanner
Published: March 2020

South Atlantic water masses and circulation significantly influence the dynamics and water mass structure of the Atlantic Meridional Overturning Circulation (AMOC). Previous research in the South Atlantic has mostly focused on energetic regions such as the Brazil/Malvinas Confluence Zone along the western boundary and the Agulhas retroflection to the east. However, it is also important to understand water circulation and diapycnal mixing within the South Atlantic Basin (SAB). Previous studies have observed low salinity patches of the Antarctic Intermediate Water within the western side of the SAB at 30o S, but the temporal variability of the scales, locations and structures of these low salinity patches are still uncertain. Former studies also show an increased level of mixing within the SAB above the Mid-Atlantic Ridge, but did not evaluate mixing on smaller scales such as mesoscale and sub-mesoscale.

Here we present a water mass structure analysis at 30o S from Rio Grande Rise to the Mid-Atlantic Ridge by using Seismic Oceanography (SO). SO is being applied around the world to image mesoscale water mass structures using the seismic reflection method. Reflections in the seismic images are essentially temperature gradients that are proxies for isopycnal surfaces. We paid particular attention in seismic processing to imaging of structures that characterize the boundary between water masses. We imaged the upper South Atlantic Central Water, and identified discontinuous water boundaries (about 150 km long) between the Antarctic Intermediate Water and the North Atlantic Deep Water that could correspond to the intermittent appearance of low salinity patches. We combine seismic images with previous hydrographic measurements to investigate the temporal change of these low salinity patches. We use a horizontal slope spectra to quantify mixing rate from tracked seismic horizons to evaluate mesoscale and sub-mesoscale mixing events such as internal waves and eddies. Through SO, we hope to better constrain South Atlantic circulation and contribute to the understanding of AMOC as a whole.
A web based Geospatial Decision Support System to quantify the impact of soil sealing on soil functions
Authors: Manna Piero , Basile Angelo , Bonfante Antonello , D'Antonio Amedeo , De Michele Carlo , Iamarino Michela , Langella Giuliano , Mileti Florindo Antonio , Munafò Michele , Terribile Fabio
Published: March 2020

Soil sealing is considered one of the most dangerous land degradation processes on global, European and national scales. Numerous policies aiming to mitigate this soil threat testify the importance of the phenomenon, which however is continuously growing, or at least does not shows signs of abating. Here we would show a spatial decision support system (S-DSS) – based on a Geospatial Cyberinfrastructure – with the aim of applying it as an operational instrument aiming towards soil sealing mitigation. The system developed within the framework of the LANDSUPPORT EU project (www.landsupport.eu) started on May 2018 has the ambition to impact on those who take decision over soil sealing issues.  It currently represents an evolution of a previous S-DSS tool named Soil sealing and landscape planning, still operational and described in a scientific publication (https://doi.org/10.1002/ldr.2802). The system, focusing on mitigating such crucial land degradation, allows the users - freely and via the Web – to produce ‘what-if’ land planning scenarios thanks to the ‘on-the-fly’ modelling engines. Therefore, integrated geospatial quantitative data and procedures may be directly and freely used by planners. The system is continuously evolving and is thought to function on the fly from local (administrative limits) to the European scale, addressing among others the issues of rural fragmentation, loss of soil ecosystem services, estimates of soil sealing evolution over time, etc. The tool is being developed with the help of end users and indirectly explores a change of paradigm where soil science and landscape/urban planning work together to provide operational instruments that may be adopted by local communities in addressing soil sealing issues with a proactive approach.
Direct fault states assessment from wavefield properties: application to the 2009 L’Aquila earthquake
Authors: Shi Peidong , Seydoux Léonard , Poli Piero
Published: March 2020

Monitoring and investigating the physical states of active faults is essential to understand how earthquakes begin and the physical processes involved. Traditionally, fault-state investigation strategies use seismic catalogs whose completeness and accuracy may be limited. We propose to take benefit of the information encoded in the continuous seismograms in order to fully extract information about the fault physics. We calculate the covariance matrix spectrum of continuous seismograms at an array of stations and extract features (e.g. entropy, spectral width, variance and coherency) from the covariance matrix eigenvalue spectrum. Those features are related to seismic source characteristics (e.g. source localization, spectral content, duration...) in the time scale of analysis, and can be used to reveal different physical states of faults. The dominant frequency band of the seismic wavefield changes at different stages of fault activities. Therefore, we perform clustering to characterize the physical states of fault based on the extracted frequency-dependent features. We apply this approach to investigate the 2009 L’Aquila earthquake. At preparation phase of the L’Aquila earthquake, foreshocks are localized around the main active fault. In contrast, the aftershocks disperse in a more broaden area where the faults have been activated by the mainshock. The extracted features and corresponding clustering results are able to capture and distinguish those patterns of earthquake distribution. In addition, the locations of the seismic sources are encoded in the covariance matrix eigenvectors. Through clustering and migration of eigenvectors, we are able to reveal the spatial and temporal variation of the different seismic sources. The method is here applied to study recent earthquakes in Italy as the L’Aquila 2009, Emilia 2012 and Norcia 2016.
MMS Observations of the Charge State and Mass Dependent Energization of Heavy Ions During Injections in the Earth’s Magnetotail
Authors: Bingham Sam , Cohen Ian , Mauk Barry , Mitchell Don , Turner Drew , Fuselier Stephen
Published: March 2020

Particle injections transport particles from the Earth’s magnetotail to the inner magnetosphere. During this process, ions in the injections are substantially energized. The physical processes behind this energization are still under debate. Recent results from the Van Allen Probes mission at radial distances < 6 RE have shown that higher mass ions (helium and oxygen) with high charge states are often found at substantially higher energies than protons (up to MeV energies compared to a couple hundred keV) in the inner magnetosphere. Here we present results from the Magnetospheric Multiscale (MMS) mission over a broad range of radial distances (between 7-25 RE) where the energization of injected ions is charge state dependent. We demonstrate with these observations that injected ions exhibit behavior which is well ordered by energy per charge due to the gradient/curvature drift’s impact on particle trajectories as they drift in the direction of transient electric fields. The charge state dependent energization leads to the dominance of multiple charge state heavy ions, as opposed to H+, above ~250 keV throughout the Earth’s inner and middle magnetosphere. Additionally, there are also cases with hints of non-adiabatic energization observed in O+ between ~100-250 keV, where O+ potentially gets some extra-energization compared to H+ due differences in their respective gyroradii. However, the highest energy ions (> 300 keV oxygen and helium) are still likely of solar wind origin and primarily accelerated due to their higher charge-state. In the process of these results we demonstrate the utility of a technique for deducing ion charge-states using instrumentation that does not directly discriminate by charge state.
Better data for geographic targeting of resources: the role of earth observation data for mapping social and economic conditions.
Authors: Watmough Gary , Campbell Amy , Marcinko Charlotte , Palm Cheryl , Svenning Jens-Christian
Published: March 2020

Planning for disaster responses and targeting interventions to mitigate future problems requires frequent, up-to-date data on social, economic and ecosystem conditions. Monitoring socioeconomic conditions using household survey data requires national census enumeration combined with annual sample surveys on consumption and socioeconomic trends, the cost of which is prohibitive. We examine the role that Earth Observation (EO) data could have in mapping poverty in rural areas by exploring two questions; (i) can household wealth be predicted from RS data? (ii) What role can EO data play in future geographic targeting of resources? Here, we demonstrate that satellite data can predict the poorest households in a landscape in Kenya with 62% accuracy. When using a multi-level approach, a 10% increase in accuracy was achieved compared to previously used single-level methods which do not consider how landscapes are utilised in as much detail. EO derived data on buildings within a family compound (homestead), amount of bare agricultural land surrounding a homestead, amount of bare ground inside the homestead and the length of growing season were important predictor variables. A multi-level approach to link RS and household data allows more accurate mapping of homestead characteristics, local land uses and agricultural productivity. High-resolution EO data could provide a limited but significant contribution to geographic targeting of resources, especially when sudden changes occur that require targeted responses. The increasing availability of high-resolution satellite data and volunteered geographic data means this method can be modified and upscaled to larger scales in the future.

 