bluuebunny/crossref_metadata_2025 huggingface dataset:
Short-duration extreme convective precipitation in the southeastern Alpine forelands of Austria under climate warming
Authors: Kabir Md. Humayain , Kirchengast Gottfried
Published: March 2020

The expected intensification of short duration extreme convective precipitation events (SDECPEs) under climate change likely leads to an increase of flash floods and landslides in vulnerable catchments such as the Styrian Raab catchment in the southeastern Alpine forelands of Austria. These extreme events may have strongly adverse effects on different sectors such as public infrastructure, households, and agriculture. Therefore, a clear understanding of SDECPEs is crucial to avoid severe damage risks.

In this work we aim to assess in this context the fingerprint of climate warming in SDECPE’s sub-hourly and hourly rainfall intensities in the southeastern alpine forelands in summertime from data over 1961-2019 within a southeast Austria focus region. We use high-resolution precipitation and temperature time series, and auxiliary data, from 20 gauges of the Austrian weather service (ZAMG) and the Austrian hydrographic service (AHYD) over 1961 to 2019 and additionally from the dense WegenerNet network of around 150 stations in southeast Austria, available over 2007 to 2019. Complementary synoptic data over the greater Alpine region, mainly from the European Reanalysis ERA5, help in convective-event weather typing and interpretation. Weather typing through principal component and cluster analysis as well as artificial intelligence methods and joint station analyses aid to assess the SDECPE changes.

It is found that extreme summertime precipitation in this region is frequently of short-term convective type and its intensity increased. According to previous work on temperature-precipitation scaling (Schroeer and Kirchengast, Clim.Dyn., doi:10.1007/s00382-017-3857-9, 2018), sub-hourly and hourly SDECPE intensities scale at super-CC rates in the region (about 9–14 % per °C) and we will report preliminary results on the rainfall intensification over the long-term time horizon from 1960 to present.

 
Wavefield reconstruction inversion for ambient seismic noise
Authors: de Ridder Sjoerd A.L. , Maddison James R. , Shaiban Ali , Curtis Andrew
Published: March 2020

With the advent of large and dense seismic arrays, there is an opportunity for novel inversion methods that exploit the information captured by stations in close proximity to each other. Estimating surface waves dispersion is an interest for many geophysical applications using both active and passive seismic data. We present an inversion scheme that exploits the spatial and temporal relationships of the Helmholtz equation to estimate dispersion relations directly from surface wave ambient noise data, while reconstructing the full wavefield in space and frequency. The scheme is a PDE constrained inverse problem in which we jointly estimate the state and parameter spaces of the seismic wavefield. Key to the application on ambient seismic noise recordings is to remove the boundary conditions from the PDE constraint, which renders a conventional waveform inversion formulation singular. With synthetic acoustic and elastic data examples we show that using a variable projection scheme, we can iteratively update an initial estimate of the medium parameters and recover an estimate for the true underlying velocity field. Our examples show that the we can reconstruct the full wavefield even in the case of strong aliasing and irregular sampling. This works forms the basis for a new approach to inverting ambient seismic noise using large and dense seismic arrays.
Spatio temporal visualization of soil critical sources areas to assess the dynamics of source pollution in agricultural management practices
Authors: Uribe Natalia , Corzo P Gerald A
Published: March 2020

Spatio temporal visualization of soil critical sources areas to assess the dynamics of source pollution in agricultural management practices

always changes aim at the reduction of nutrient pollution. Critical identification of areas that are the sources of pollution is crucial for identifying which practices provide the most substantial contamination. The dynamics of agricultural practices are complex and the precise determination of pollution concentration requires a comprehensive model. In this research, we present the results of analysing via a new visualisation technique were the critical source areas using a spatiotemporal methodology that allows for a georeferenced identification of changes. The proposed method in this research used a radial diagram to evaluate the changes in regions of pollution and makes a radial diagram formulation of intensities, location and frequency. For this location and intensity identification, a clustering process, using the Non-contiguous drought areas method and the Contrigous drought area method. This clustering groups by first mapping in one dimension the threshold that defines a change in the state of the CSA, and then groups if by its neighbours and soil characteristics. To obtain a spatially distributed data, a SWAT model was set up for two types of crops, mainly potato and tomato tree, aside, we added also Kikuyu grass as it is one of the most important in the region. The simulation period for our experiment was in an area of 103434 Ha, using daily data from 1995 to 2015.  Two steps calibration was done, first with streamflow and second with an analysis of monthly nutrients. Results show a definite change in location, which will imply that a significant error could be present if the spatiotemporal relation is not analysed. The current work is part of a PhD thesis and the partial results presented here contribute to a broader formulation of the optimisation of agricultural practices to reduce the impact of the Critical Source Areas in nutrients pollution. 

 
Analysis of Local Regimes of Turbulence generated by 3D Magnetic Reconnection
Authors: sanna lucia , lapenta Giovanni
Published: March 2020

The process of magnetic reconnection when studied in nature or when modeled in 3D simulations differs in one key way from the standard 2D paradigmatic cartoon: it is accompanied by many fluctuations in the electromagnetic fields and plasma properties. We developed a diagnostics to study the spectrum of fluctuations in the various regions around a reconnection site. We define the regions in terms of the local value of the flux function that determines the distance from the reconnection site, with positive values in the outflow and negative values in the inflow. We find that fluctuations belong to two very different regimes depending on the local plasma beta (defined as the ratio of plasma and magnetic pressures). The first regime develops in the reconnection outflows where beta is high and it is characterized by a strong link between plasma and electromagnetic fluctuations, leading to momentum and energy exchanges via anomalous viscosity and resistivity. But there is a second, low-beta regime: it develops in the inflow and in the region around the separatrix surfaces, including the reconnection electron diffusion region itself. It is remarkable that this low-beta plasma, where the magnetic pressure dominates, remains laminar even though the electromagnetic fields are turbulent.

[1] G. Lapenta et al 2020 ApJ 888 104,
Evaluation of the spatio-temporal development of hydrological droughts and its sensitivity to the choice of different parameters of the hydrological model. Case study: Magdalena-Cauca River basin – Colombia
Authors: Corzo P Gerald A , Aguilar Carrillo Fabio , Cotrino Palma Juan Manuel , Santos Granados German Ricardo
Published: March 2020

Title:

Evaluation of the spatio-temporal development of hydrological droughts and its sensitivity to the choice of different parameters of the hydrological model. Case study: Magdalena-Cauca River basin – Colombia

Abstract:

Droughts in Colombia have been studied using local and regional indicators; however, the nature of events and the heterogeneity of mountains, and the high variability of climate and hydrological process, indicate that this should follow a more dynamic spatiotemporal analysis. In previous studies about drought, it has been possible to identify how natural drought phenomena tend to spread irregularly through large regions. This research aims to develop a spatiotemporal evaluation of hydrological droughts in Colombia. The process of the analysis followed three main components, one estimating the drought indicator to the interpolated data set from the local agency IDEAM. This step aims to find the optimal combination of parameters sets to characterize the hydrological behavior; to determine standardized runoff, soil moisture and evaporation deficit indices (SRI, SSMI, SEDI respectively). Second, the determination of the patterns using the Contiguous Drought Area (CDA) and Non-Contiguous Drought Area (NCDA) methodologies to characterise the spatio-temporal behaviour of the hydrological droughts. And before concluding an assessment of the robustness of the drought events, a threshold sensitivity analysis was performed. The body of the study includes a complete conceptual framework with the definition of hydrological droughts and drought indices (DI). This methodology is based on the characterization spatiotemporal droughts that examines the patterns of events using results from previous studies. The results of this analysis are key for the preparedness of the region to extreme events.
High probability of yield gain through conservation agriculture in dry and cool regions for major staple crops
Authors: Su Yang , Gabrielle Benoit , Beillouin Damien , Makowski David
Published: March 2020

Conservation agriculture (CA) has been promoted to reduce land degradation, improve the soil fertility, the soil structure and increase the level of soil organic carbon over time. It is expected to mitigate climate change and enhance the resistance of crops to the changing climate. Yet, its impacts on crop yields remains controversial. To gain further insight on the sustainability of CA, we mapped the probability of yield gain when switching from conventional tillage systems (CT) to CA worldwide. The range of yield changes were estimated with machine learning algorithms trained by 2828 paired yield observations on 8 crop species extracted from 323 publications. CA stands a more than 50% chance to outperform CT in dry and cool regions of the world, while it can lead to yield losses of up to 59% in warmer and wetter regions. Residue retention has the largest positive impact on CA productivity compared to other management practices. The promising and the risky regions for CA global implementation were identified. The productive performance of CA for different crops in future climate were also estimated and mapped globally, the results of different scenarios were compared and analyzed. Overall, with proper managements, CA appears as a sustainable agricultural practice for specific climatic regions and crop species.
Combining morphological and organic geochemical evidence for investigating putative ichnofossils: A case study for an approach for the detection of fossilised life on Mars
Authors: Purvis Graham , van der Land Cees , Sano Naoko , Cumpson Peter , Gray Neil
Published: March 2020

The procedures for detecting fossils on Mars can be derived from the methods that are already used in terrestrial paleobiology (Cady et al., 2003). Here fossils preserving regions are visually located, then inspected for morphological features that might imply fossilised biology (Cady and Noffke, 2009; Westall et al., 2015). Morphological evidence of microfossils on its own is not a completely reliable biosignature (García Ruiz et al., 2002).  However, evidence of biological activity may be implanted within the molecular and isotopic composition of organic compounds, which can serve as biosignatures (Summons et al., 2008). Thus, combining both morphological with organo-geochemical evidence could strengthen any argument that a given geological feature could be associated with biological activity. The results from the simultaneous morphological and geochemical analysis of geobiological structures on Earth could provide evidence that any comparable structures that may be observed on Mars, are potentially connected to biological activity, and therefore, may be suitable for collection for return to the Earth, for further analysis.

As a proof of concept, the distribution of the organic material that is associated with distinctive microtubules in the glassy volcaniclastic shards within tuff, that have been suggested to be putative ichnofossils (Banergee and Muehlenbachs, 2003), these were analysed by us using X-ray photoelectron spectroscopy, nanoSIMS and the Ionoptika J105 time of flight secondary ion mass spectrometer, with  an argon gas cluster ion beam. This indicated that nitrogenous organic material occurred in regions of the sample that were rich in microtubule textures and in the surrounding microfractures (Sano et al., 2016). 

These results demonstrated that the J105 ToF-SIMS combined with XPS and GC/MS analysis is able to match geomorphological features with their organic and inorganic composition at the µm scale, which may be a useful approach for the identification of fossilised life on Mars.

References:

Banerjee et al., (2003). Geochemistry, Geophysics, Geosystems, 4(4).

Cady et al., (2003). Astrobiology, 3(2), pp.351-368.

Cady et al., (2009). GSA Today, 19(11).

García Ruiz et al., (2002). Astrobiology, 2(3), pp.353-369.

Summons et al., (2008) Astrobiology, 90, 1151–1154.

Westall, F., et al., (2015). Astrobiology, 15(11), pp.998-1029.

Sano, N et al., (2016). J. of Vac Sci & Tech A: 34(4), p.041405
The History of the Earth in the hallways
Authors: Ramírez Vongrejova Paloma , Massé Rodríguez María José
Published: March 2020

There is widespread agreement among my fellow colleagues who teach Geology that the History of our planet is a tough topic for teenagers. Unfortunately, not only is the subject considered boring but also useless by the majority of our school students.

Our experience teaching these contents in a traditional way has shown us that pupils vaguely remember anything. In order to give a different approach to this issue and, therefore, to promote meaningful learning, we have designed a project where students must be fully engaged.

First, the class was organized in cooperative learning groups, so they had to collaborate to complete the task. Then, they started the research period using laptop computers available in the school. Students now dealt with specific vocabulary such as the geologic time scale terms but also a variety of events that occurred from the very first moments, from the formation of the Earth itself to the development of the big reptiles that have always fascinated children and adults, especially their dramatic extinction.

 Once the topic was developed in detail, they were required to make a poster on scale with the information collected. It was undeniable that pictures or photographs must cover most of the poster as long as short sentences describing both biological and geological phenomena. What we were also concerned about their learning was to improve their creativity. Because of this, they were encouraged to make their own drawings.

Students really liked the activity, built stronger relationships between them and the final products were so amazing that were exhibited in the walls of the hallways outside their classroom.

All these events have been recorded in the rocks so geologists could unfold part of the mysteries of our History. Our teenagers discovered them an represented them for us to enjoy.
Space-time variability of soil moisture based drought in the transboundary Koshi river basin of the Himalayan region
Authors: Nepal Santosh , Pradhananga Saurav , Shrestha Narayan , Shrestha Jayandra , Fink Manfred , Kralisch Sven
Published: March 2020

Soil moisture is an important part of the vegetation cycle and a controlling factor for agriculture. Withstanding the role of agricultural productivity in economic development of a nation, it is imperative that water resources planners and managers are able to assess and forecast agricultural drought. As agricultural drought is related to declining soil moisture, this paper studies the dynamics of soil moisture based drought in the transboundary Koshi river basin in the Himalayan region. By applying the J2000 hydrological model, the daily soil moisture is derived for the whole basin for a 28-year time frame (1980-2007). The soil moisture deficit index (SMDI) is calculated based on a fully distributed spatial representation by considering the derivation from the long term soil moisture on a weekly time scale. In order to analyze the variation of soil moisture drought spatially, the river basin is subdivided into three distinct geographical areas, i.e. Northern Tibet, High and Middle Mountains, and Southern Plain. Further, temporally the SMDI is calculated for four distinct seasons based on wetness and dryness patterns observed in the study area, i.e. monsoon, post-monsoon, winter and pre-monsoon. A multi-site and multi-variable (streamflow at one station and evapotranspiration at three stations) approach was used for the calibration and validation of the J2000 model. Results show that the J2000 model is able to simulate the hydrological cycle of the basin with high accuracy. The model properly represents the winter drought of 2005 and 2006 was the most severe drought in the 28-year time period. Results also show considerable increases in the frequency of pre-monsoon and post-monsoon soil moisture drought in recent years. Severe droughts have had a high frequency in recent years, which is also reflected by an increase of areas that were impacted. In summary, our results show that severity and occurrence of agricultural drought has increased in the Koshi river basin in the last three decades, especially in the winter and pre-monsoon. This will have serious implications for agricultural productivity and for water resources management of the basin.
Effect of biomass cutting on soil CO2 efflux in a sandy grassland
Authors: Papp Marianna , Fóti Szilvia , Pintér Krisztina , Nagy Zoltán , Balogh János
Published: March 2020

Carbon storage in grassland ecosystems is realized mostly belowground. The changes in the management activities of grasslands also influence the below-ground carbon stocks. Soil carbon-dioxide efflux (Rs) takes a major part of the ecosystem’s carbon cycle. Rs includes the respiration of different components. Rs gives 60-80% of ecosystem respiration or 40-60% of gross primary production. It is known from the literature that respiration is affected by abiotic (temperature (Ts), soil water content (SWC)) and the biotic factors.

In our study we investigated the biotic one, namely the belowground carbon allocation on soil respiration. The study was performed in a semi-arid sandy grassland at Bugac (Kiskunság National Park, Hungary). The vegetation of the pasture was dominated by Festuca pseudovina, Carex stenophylla and Cynodon dactylon and the soil is a chernozem type soil with high organic carbon content.

The soil CO2 effluxes were measured continuously by an automated soil respiration system consisted of 10 soil respiration chambers. The chambers measured 3 different experimental plots. Data was collected in every half-hour from each chamber for 6 days before the cutting event. After the cutting data was recorded from 1) non-cut, 2) half cut and 3) completely removed treatments also for 6 days. The study was repeated under laboratory conditions (constant temperature, illumination, humidity) on grass patches planted in pots. We observed that the respiration in half cut and completely removed treatments increased after they were cut off. The proportion of respiration after cutting in the completely removed treatment reduced to 85% compared to the control one. Our results highlight that the soil respiration is largely affected by belowground carbon allocation.
Results of the cyberparks cost action tu 1306
Authors: Malinverni Eva Savina , Pierdicca Roberto , Smaniotto Costa Carlos , Bahillo Martinez Alfonso , Marcheggiani Ernesto
Published: March 2020

The present abstract is aimed at describing the activities and results about Cyberparks COST Action TU 1306. The purpose of the action was to increase the knowledge about the existing relationship between Information and Communication Technologies (ICT) and Public Spaces, supported by strategies to improve their use and attractiveness. In such scenario, the project developed several case studies to develop best practices and digital tools able to collect information directly from the users, in real time. Indeed, sensors where installed in Public Spaces, as well as mobile applications that allowed to provide user’s with contextual information and Location Based Services and, at the same time, to collect the so called User Generated Data. In such way, people experiencing a certain place could enhance their knowledge and administration (or public authorities) could understand how user’s exploit it. Moreover, the project stimulated the use of new technologies like Augmented Reality as an additional service, useful to discover the surrounding and enhance the sense of presence of the users. CyberParks allowed to uncover opportunity and risks related to the use of ICTs via the appreciation, design and usage of public spaces. It exploited the benefits of interweaving a green experience with digital engagement via sharing knowledge, experiences and ideas, and analyzing public spaces.

The methodology developed can be of great interest especially for urban planning purposes; in fact, the pen-and-pencil approach for redesigning and rethinking a place can be partially replaced by a data driven approach, that can be more objective and reliable.

More than 50 scientific papers were published and very fruitful Short Term scientific missions. A great number of data was collected from real scenario, demonstrating the effectiveness of the methods adopted to conduct researches and experiment. Another noteworthy output of the project is the exploitation of a multidisciplinary group. In fact, the amalgamation of researchers coming from different scientific disciplines allowed to enhance the knowledge and strength cooperation between humanistic disciplines and digital sciences.
Can we distinguish tsunami and storm deposits based on their microbial composition?
Authors: Yap Wenshu , Adam Switzer , Chris Gouramanis , Dale Dominey-Howes , Maurizio Labbate , Federico Lauro
Published: March 2020

 

Can we distinguish tsunami and storm deposits based on their microbial composition?

 

Wenshu Yap1,2,3, Adam D. Switzer 1,2, Chris Gouramanis4, Dale Dominey-Howes5, Maurizio Labbate6, Federico M. Lauro1,3

 

1 Asian School of the Environment, Nanyang Technological University, 50 Nanyang Drive, Singapore 639798

2 Earth Observatory of Singapore, Nanyang Technological University, 50 Nanyang Drive, Singapore 639798

3 Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, 60 Nanyang Drive, Singapore 639798

4 Department of Geography, National University of Singapore, Kent Ridge, Singapore 117570

5 Asia-Pacific Natural Hazards and Disaster Risk Research Group, School of Geosciences, University of Sydney, NSW 2006, Australia

6 School of Life Sciences, University of Technology Sydney, NSW 2007, Australia

 

One of the challenges in the study of coastal hazard is to reliably distinguish between storm and tsunami deposited sediments. This limitation compromises the quality and accuracy of reconstructing historical coastal flooding records, and is thus an issue to a variety of policy makers and stakeholders interested in assessing the risk and vulnerability of coastal communities. Here we describe a microbial community signature based on amplicon sequencing of DNA extracted from environmental samples collected from two different locations i.e. Cuddalore, India and Phra Thong Island, Thailand. Both locations were impacted by the 2004 Indian Ocean Tsunami and a subsequent storm event. Our results show that the microbial community in the tsunami deposits are significantly different from that found in the storm deposits as well as soil and terrestrial sediments (PERMANOVA, p-value <0.01) in both locations. The microbial community differences between the tsunami deposits and storm deposits are not statistically correlated with chemical data such as total Nitrogen, total Carbon and total Sulfur, implying that our microbial signature is insensitive to environmental and geochemical variability. Integrating molecular techniques to investigate geological records is powerful and statistically robust in discriminating between modern tsunami and storm deposits.
Geological Map Of The Debussy Quadrangle of The Planet Mercury
Authors: Pegg David. L. , Rothery David. A. , Balme Matt. R. , Conway Susan. J.
Published: March 2020

Geological mapping of Mercury is crucial to build an understanding of the history of the planet and to set the context for observations made by the recently launched BepiColombo mission when it begins science operations in orbit around Mercury in 2026. I am mapping the geology of the Debussy quadrangle (approximately 1/15th of the planet) as part of a pan-Europe program to map the entire planet at a scale of 1:3M using data from NASA’s MESSENGER mission. This will be the first high-resolution map of this part of Mercury. The mapped area includes the Rembrandt impact basin, the second largest on the planet, Enterprise Rupees, the longest tectonic fault as well as several explosive volcanic vents and terrains of different ages. Mapping began in October 2017 using ArcGIS software. The mapping follows the EU Plan map standards and USGS guidelines with linework drawn at 1:300k. Craters larger than 5 km have been outlined. Ejecta, where observed, is being traced for craters larger than 20 km and classified. Craters are classified based on crater degradation using both 3 class and 5 class schemes to enable comparison between historical and current maps of the rest of the planet and to enable placing features and units into context. A separate mapping layer for superficial shows the most recent modifications to Mercury’s surface, including volcanic deposits and impact craters. I present the map and with working geological interpretation.
Benthic investigations at the Arctic long-term deep-sea observatory HAUSGARTEN
Authors: Hasemann Christiane , Schewe Ingo , Soltwedel Thomas
Published: March 2020

The past decades have seen remarkable changes in key arctic variables, including a decrease in sea-ice extent and sea-ice thickness, changes in temperature and salinity of arctic waters, and associated shifts in nutrient distributions. To detect and track the impact of large-scale environmental changes in the transition zone between the northern North Atlantic and the central Arctic Ocean, the Alfred Wegener Institute for Polar and Marine Research (AWI) established in 1999 about 150 km west of Svalbard the deep-sea long-term observatory HAUSGARTEN, which constitutes the first, and until now only open-ocean long-term station in a polar region. 21 permanent sampling sites along a depth transect between 1000 – 5500 m, and along a latitudinal transect following the 2500 m water depth isobath are revisited yearly. The central HAUSGARTEN station serves as an experimental area for biological short- and long-term experiments at the deep seafloor, simulating various scenarios in changing environmental settings. Multidisciplinary research activities at HAUSGARTEN comprise biochemical analyses to estimate the input of organic matter from phytodetritus sedimentation and activities and biomasses of the small sediment-inhabiting biota as well as assessments of distribution patterns of benthic organisms (covering size classes from bacteria to meiofauna as well as megafauna).The past decades have seen remarkable changes in key arctic variables, including a decrease in sea-ice extent and sea-ice thickness, changes in temperature and salinity of arctic waters, and associated shifts in nutrient distributions. To detect and track the impact of large-scale environmental changes in the transition zone between the northern North Atlantic and the central Arctic Ocean, the Alfred Wegener Institute for Polar and Marine Research (AWI) established in 1999 about 150 km west of Svalbard the deep-sea long-term observatory HAUSGARTEN, which constitutes the first, and until now only open-ocean long-term station in a polar region. 21 permanent sampling sites along a depth transect between 1000 – 5500 m, and along a latitudinal transect following the 2500 m water depth isobath are revisited yearly. The central HAUSGARTEN station serves as an experimental area for biological short- and long-term experiments at the deep seafloor, simulating various scenarios in changing environmental settings. Multidisciplinary research activities at HAUSGARTEN comprise biochemical analyses to estimate the input of organic matter from phytodetritus sedimentation and activities and biomasses of the small sediment-inhabiting biota as well as assessments of distribution patterns of benthic organisms (covering size classes from bacteria to meiofauna as well as megafauna).
Changes in land surface and weather forecasting
Authors: Rousta Iman , Ólafsson Haraldur
Published: March 2020

The Normalized Difference Vegetation Index (NDVI) has been retrieved and analyzed for Iceland.  There are only limited trends in the total integrated NDVI in the period 2001 - 2018.  However, there is a positive trend in recent decades in the occurrence of signal corresponding to woodland and forests.   Locally, there may however be great changes; some small deserts have turned green and systematic planting of trees in certain regions is well detectable. The impact, and the driver of these changes are discussed in the context of climate and the implication for thermally driven weather systems and local weather forecasting is explained. 
The Ice, Cloud, and Land Elevation Satellite – 2 (ICESat-2): Mission Status, Science Results, and Outlook
Authors: Kurtz Nathan , Neumann Thomas , Magruder Lori
Published: March 2020

The Ice, Cloud, and Land Elevation Satellite-2 has entered it’s second year on orbit, and continues to collect high-quality measurements of the changing cryosphere. The Advanced Topographic Laser Altimeter System (ATLAS) has now emitted more than 500 billion laser shots which provide elevation measurements of sea ice and the polar oceans, glaciers and ice sheets, the world’s forests, oceans, lakes and rivers in addition to vertical profiles of clouds and aerosols. ATLAS is an innovated lidar technology that utilizes low power and higher repetition rates to collect measurements every 70 cm along-track. These measurements have been shown to have high precision and accuracy comparable to or better than past and present cryospheric missions. The ICESat-2 data has also shown great promise with its ability to act as both complementary observations to many other missions as well as allow for us to extend the timeseries associated with our understanding of elevation and mass change in the polar regions. In this presentation, we will provide an update on the operations and health of the observatory, review the many available data products served through the National Snow and Ice Data Center in the US, and highlight the early science results from the mission. As of this writing, more than 2.5 million data granules have been downloaded by 1500 unique data users. Initial science papers have documented the ongoing loss of mass from the Antarctic and Greenland ice sheets, the ability of ICESat-2 to measure the seasonal changes in sea ice freeboard and thickness throughout the year, and the potential for world-wide measurements of coastal bathymetry. 
Comparative Prevalence and Provenance of Antibiotic-Resistant Bacteria and Antibiotic Resistance Genes in Tropical Rivers of Sri Lanka and India
Authors: Kumar Manish , Chaminda Tushara , Hanafi Sulfikar , Patel Arbind , Mazumder Payal , Thakur Alok , Honda Ryo , Sewwandi Himaya
Published: March 2020

Abstract:

Prevalence and provenance of antibiotic-resistant bacteria (ARB), antibiotic resistance genes (ARG) and metal concentrations were compared in river Kelani of Sri Lanka and Sabarmati and Brahmaputra of India. The prevalence of E. coli was 10-27, 267-76,600 and <50 CFU ml-1 in aforementioned rivers, respectively. Isolated E. coli colonies were subjected to resistance test with norfloxacin (NFX), ciprofloxacin (CIP), levofloxacin (LVX), kanamycin monosulphate (KM), tetracycline (TC), and sulfamethoxazole (ST). The isolates were predominantly multi-antibiotic resistant, with greater resistance to TC and ST. Brahmaputra River showed greater resistance to all tested antibiotics. Sabarmati River showed higher resistance to TC and ST than Kelani. Genes conferring resistance to tetracyclines, sulphonamides, b-lactams and fluoroquinolones were common. ARG, gyrA, tetW, sul1 and ampC were detected in Kelani River, additionally, aac-(6’)-1b-cr, and blaTEM were detected in Brahmaputra River. In both countries, less polluted segments exhibited more copies of ARG. Faecal contamination was decoupled from percentage antibiotic resistance and metal contamination, suggesting to separate of hospital waste from domestic waste with specific guidelines.

 

Keywords: Antibiotic Resistance; Brahmaputra; E. coli; Kelani River; Sabarmati, Gene
Dissemination of modeled and satellite derived flood products: Global coverage to support local needs
Authors: Kettner Albert , Schumann Guy , Brakenridge Robert , Adler Bob , Policelli Fritz , Slayback Daniel , Matgen Patrick , Souffront Michael , Shen Xinyi
Published: March 2020

The demand for timely and accurate flood information is well understood and more urgent than ever as flooding has become the most common natural hazard worldwide, impacting people of all continents in both developed and less developed countries. Population and total exposed assets by river flooding are certain to increase in the coming century making the need for flood information even more pressing. Unlike the World Meteorological Organization (WMO), the hydrological community hasn’t been very successful in establishing a global hydrological network of observations through which model simulations and measurements and novel measurement technologies could be exploited. Countries that can afford have departments in place that are tasked to develop flood risk maps and are involved in flood forecasting and relief efforts. However, the majority of countries do not or cannot allocate sufficient funds to support such efforts, nor has there been a global initiative to identify and determine global flood risk areas.

Due to the lack of objective knowledge of the impact of flooding during or after an event, first relief agency assistance is often constrained and therefore less effective. These humanitarian catastrophes could be reduced with better transformation of existing observational and modeling technologies into information useful to local populations and decision makers.

Here I present new efforts to produce a state-of-the-art, globally-scoped, flood prediction, monitoring capabilities and risk evaluations platform that is interactive and includes high resolution flood information to better serve local needs. The platform builds upon already operational or quasi-operational NASA-supported global flood systems, including the DFO - Flood Observatory satellite-based hydrological gauging stations, UMD Global Flood Monitoring System (GFMS) and have these integrated with the European Commission’s GloFAS, and SAR-based high-resolution flood mapping. This with the intension to have these data layers (flood forecasting, flood extent, and flood history) available to everybody.
Hydrochemical Classification of Groundwater with Artificial Neural Networks
Authors: Haselbeck Valentin , Kordilla Jannes , Krause Florian , Sauter Martin
Published: March 2020

Growing datasets of inorganic hydrochemical analyses together with large differences in the measured concentrations raise the demand for data compression while maintaining critical information. The data should subsequently be displayed in an orderly and understandable way. Here, a type of artificial neural network, Kohonen’s self-organizing map (SOM), is trained on inorganic hydrochemical data. Based on this network, clusters are built and associated to the salinity source distribution of the spatial variation at a former potash mining site. This combined two-step clustering approach managed to assign the groundwater analyses automatically to five different clusters, three geogenic and two anthropogenic, according to their inorganic chemical composition. The spatial distribution of the SOM clusters helps to understand the large scale hydrogeological context. This approach provides the hydrogeologist with a tool to quickly and automatically analyze large datasets and present them in a clear and comprehensible format.
Challenges raised by global ocean configurations in the context of climate modelling
Authors: Deshayes Julie
Published: March 2020

The tuning phase of IPSL-CM6A-LR, a climate model of CMIP6 using NEMO as ocean component, lasted for 4 years, during which we explored different numerical recipes controlling ocean vertical mixing, among others. Analysis of all simulations is still ongoing, but two lessons can be learned so far. [1] After more than 2,000 yr of integration (using pre-industrial external forcings), the deep ocean has not reached an equilibrium, yet. [2] Sensitivity experiments exploring structural and parametric uncertainties indicate that some intrinsic climatic features of this model are quite robust. Overall, this suggests that we currently have little control on the backbone of numerical oceans.
Explicit modelling of external and internal tidal waves in the global 1/12° NEMO ocean model
Authors: Chanut Jérôme , Bourdallé-Badie Romain , Tranchant Benoît , Allain Damien , Carrère Loren , Koch-Larrouy Ariane , Lyard Florent , Morel Yves
Published: March 2020

Ocean tides play a major role in ocean mixing, and setting up water properties, both in the deep and the shallow ocean. Whether parameterized or explicitly simulated, tides can not be ignored in modern ocean prediction models. Representing them explicitly, the approach followed here to prepare the upcoming CMEMS (Copernicus Marine Environment Monitoring Service) global prediction system, allows for the generation of a large quantity of internal waves propagating at great distances. This is a useful information for future high resolution wide swath altimetry missions but also for forcing regional systems, enabling remotely generated internal waves to enter the user domain, providing in some places an important part of the high frequency
energy.

In the present work, we review numerical aspects in the NEMO ocean model influencing the explicit representation of both external and internal tidal waves in a global 1/12° configuration. The numerical core of NEMO has indeed largely evolved recently to simulate tides, by now including the lunisolar tidal potential, Self Attraction and Loading effects, a split-explicit barotropic solver but also Lagrangian vertical coordinates to limit the spurious numerical diffusion. We report here the effect of various parameters, using data assimilative tidal models and altimetry data as references. Semi-diurnal energy budgets are also computed. Throughout this work, a systematic comparison to HYCOM results (Ansong et al. 2015 and Buijsman et al. 2016) is performed.
Urban fossil fuel CO2 emissions from space: lessons learned from the OCO missions
Authors: Lauvaux Thomas , Feng Sha , Lei Ruixue , Oda Tomohiro , Danjou Alexandre , Broquet Gregoire , Schuh Andrew , Pavlick Ryan , Elderling Annmarie
Published: March 2020

Pledges from nations and cities to reduce their carbon footprints have reinforced the needs for accurate and transparent reporting of fossil fuel emissions at various scales, with the ultimate goal of the establishments of carbon stocktake as defined by the Paris Agreement. But the assessment of anthropogenic emissions results primarily in collecting socio-economic indicators and emission factors, hence difficult to evaluate, track, or compare without a more standardized and robust methodology. Atmospheric measurements of greenhouse gases are of particular interests by offering an independent and global source of information thanks to satellite platforms observing continuously the atmospheric content of the major gases responsible for human-induced climate change.

Based on lessons learned from the NASA Orbiting Carbon Observatory (OCO)-2 mission, we present the potential of satellite-based approaches to monitor greenhouse gas emissions from large metropolitan areas across the world (Riyadh, Lahore, Los Angeles). After exploring the technical aspects and challenges of the approach, potential aerosol contamination (CALIPSO), and model requirements, we introduce the upcoming capabilities from the follow-up mission, OCO-3, dedicated in part to urban emissions with the Snapshot Area Mapping mode, the first imagery of atmospheric CO2 concentrations for hundreds of targeted cities and power plants. Early snapshots are examined with high-resolution simulations over a handful of cities. The ongoing development of assimilation systems to inform policy makers about current trends and inter-annual variations is presented and discussed. We finally examine the potential roles and objectives of satellite missions by exploring recent trends in fossil fuel emissions along with proxies of air quality (MODIS) as a unique opportunity to track not only greenhouse gas emissions but more generally the evolution of urban environments.
Initial Assessment of Precise Orbit Determination for Combined BDS-2 and BDS-3 Satellites
Authors: Tan Bingfeng
Published: March 2020

By December 2019, twenty-four new-generation BeiDou (BDS-3) Medium Earth Orbit (MEO) satellites, three Inclined Geosynchronous Orbit (IGSO) satellites and one Geostationary Orbit (GEO) satellite have been launched, symbolizing its starting of global coverage.

The observations of a very limited number of 17 International GNSS (Global Navigation Satellite System) Monitoring and Assessment Service (iGMAS) stations and 80 IGS Multi-GNSS Experiment (MGEX) stations from October 2018 to October 2019 have been processed to determine the orbits of combined BDS-3 and BDS-2 satellites. All of the latest official BDS-2 and BDS-3 satellite phase center offsets (PCOs) and other satellite parameters were used in the data process. The internal consistency (daily boundary discontinuity) and satellite laser ranging (SLR) validations are conducted for the orbit validation. The average three-dimensional root-mean-square error (RMS-3D) of 24-hour overlapping arcs for BDS-2 and BDS-3 satellites is within 0.1m and 0.15m, respectively. Satellite laser ranging (SLR) validation reports that the orbit radial component for BDS-2 and BDS-3 satellites is within 0.1m. The orbit accuracy of BDS-3 is slightly lower than that of BDS-2 satellite presently.
Detrital zircon U-Pb and Hf isotopes study of the Longshoushan Belt in the southwestern margin of the Alxa Block: Constraints on the tectonic evolution and affinity of the Alxa Block
Authors: Liu Jingna , Yin Changqing , Zhang Jian , Qian Jiahui , Xu Kaiyuan , Wu Shangjing , Xu Nanqing
Published: March 2020

     The tectonic evolution and affinity of the Alxa Block has long been controversial. The NW-SE trending Longshoushan Belt is in the southwestern margin of the Alxa Block, separated the Qilian Block. In this study, we present zircon U-Pb and Hf-isotope data of the middle and eastern Longshoushan, which could constrain the provenance and formation age of the Longshoushan Belt, and further constrain the tectonic evolution and affinity of the Alxa Block. The U-Pb ages of the detrital zircons from the amphibolite-facies metamorphosed volcanic-sedimentary rocks of the middle Longshoushan range from 3006 to 1981 Ma (peak at 2010 Ma), which were consistent with the Alxa Block and the western North China Craton, indicating that the middle Longshoushan was deposited in the Palaeoproterozoic, not in the Archean, and had tectonic affinity with the Alxa Block and the western North China Carton. Combined with the identical crustal growth events at 2.4-2.5 Ga of the middle Longshoushan, the Alxa Block and the western North China Craton, the Alxa Block was an integrated part of the Western Block of the North China Craton. The U-Pb ages of the detrital zircons from the greenschist-facies metamorphosed volcanic-sedimentary rocks of the eastern Longshoushan range from 3389 to 529 Ma (peak at 2.5 Ga and 1.0 Ga), which were highly consistent with Hexi Corridor, indicating that the eastern Longshoushan was deposited in the Cambrian, and had an affinity with the Hexi Corridor. In the Early Palaeozoic, the North Qilian Ocean subducted the Alxa Block and formed a typical trench-arc-basin system. With the closure of the North Qilian Ocean, the Central Qilian Block collided with the Alxa Block, formed the eastern Longshoushan, which was a foreland basin in the Hexi Corridor.
Influence of fluid-assisted micro-crack healing on fault permeability structure
Authors: Yehya Alissar , Rice James R.
Published: March 2020

Micro-cracks in fault damage zones can heal through diffusive mass transfer driven by differences in chemical potential, with rates controlled by temperature and pressure. The diffusion of pore fluid pressure in fault damage zones accelerates mass diffusion and assists healing processes. In this work, we use fluid flow model coupled with heat transfer and crack healing to investigate, through different scenarios, the role of subsurface warm fluid migration, along damage zones, in enhancing healing and re-shaping the fault permeability structure. Our results show that if the flow communication exists between the bed and only one side of the damage zone and not the other side, it leads to an asymmetric permeability structure caused by healing in the side circulated by fluids (ex: Rapolano geothermal area, Italy). Another scenario is when the damage zone adjacent to the fault core is not the interval with the highest permeability, as conventionally expected, which is the case of the Alpine Fault, New Zealand. As shown by our simulations, this can be due to healing by diffusive mass transfer, favored by the localized high geothermal gradients and the upward fluid migration through the fault relay structure.
Linking changing grain size distributions with the development of shelter availability for fish in the bypass reach of a hydro power plant
Authors: Pritsis Spyridon , Schwarzwälder Kordula , Szentkereszty Wolfgang , Rüther Nils
Published: March 2020

Nowadays, the aquatic biodiversity is highly under pressure due to anthropogenic changes
of rivers such hydraulic structures changing the diversity of flow and aquatic fauna as well
as sediment continuity. This can have severe consequences on the fish population in the
river reach. Fish are strongly depending on a certain substrate composition throughout all
their life stages. Juveniles e.g. are depending on a certain availability of shelter in the
substrate in order to survive this stage. Therefore we investigate the effects of changes in
the sediment composition at a Hydropower plant in Switzerland on the availability of
potential shelter for juvenile fish. The investigation is conducted as part of the EU Horizon
2020 funded project FIThydro (funded under 727830).
To reach this goal, we measured the sediment compositions at several locations in the
bypass reach with different measurement techniques such as sieving, photogrammetry
(Basegrain) and the pebble count method. Further we measured the shelter availability in
the corresponding locations, using the so called Finstad method. As the method was
developed purely for Atlantic salmon, we modified it by expanded the variability of
available sizes. The resulting correlation of the grain size distribution with the potential
shelter availability at different locations showed a fairly high correlation coefficient. This
equation can then be used in hydro-morphological models to estimate the spatial
distribution of potential shelter availability for any given flow regime and grain size
distribution. Further investigation at other sites will over time enlarge the database and
therefore improve the correlation.