bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetic reconnection induced by the Kelvin-Helmholtz vortex at the Earth’s magnetopause during southward IMF
Authors: Nakamura Takuma , Plaschke Ferdinand , Hasegawa Hiroshi , Liu Yi-Hsin , Hwang Kyoung-Joo , Blasl Kevin Alexander , Nakamura Rumi
Published: March 2020

When the magnetic field is oriented nearly perpendicular to the direction of the plasma shear flow, the flow easily satisfies the super-Alfvénic unstable condition for the Kelvin-Helmholtz (KH) instability. This configuration is realized at the Earth’s low-latitude magnetopause when the interplanetary magnetic field (IMF) is strongly northward or southward. Indeed, clear signatures of the KH waves have been frequently observed during periods of the northward IMF. However, these signatures have been much less frequently observed during the southward IMF. In this work, we performed the first 3-D fully kinetic simulation of the KH instability at the magnetopause under the southward IMF condition. The simulation demonstrates that magnetic reconnection, with a typical fast rate on the order of 0.1, is induced at multiple locations along the vortex edge in an early non-linear growth phase of the KH instability. The reconnection outflow jet, which grows in the direction nearly perpendicular to the initial shear flow, significantly disrupt the flow of the non-linear KH vortex. On the other hand, the shear and vortex flow strongly bends and twists the reconnected field lines towards the direction out of the reconnection plane. The resulting coupling of the complex field and flow patterns within the magnetopause boundary layer leads to a quick decay of the vortex structure. These simulation results suggest that clear signatures of the KH waves are expected to be observed only for a limited phase during periods of the southward IMF, which may explain the difference in the observation probability of KH waves between northward and southward IMFs.
The Chile subduction zone : Nature of the lithosphere between alternating regions of slow earthquakes versus non slow earthquakes
Authors: Mukherjee Pousali , Ito Yoshihiro , S. Garcia Emmanuel , Plata-Martinez Raymundo , Shibutani Takuo
Published: March 2020

Subduction zones host some of the greatest megathrust earthquakes in the world. Slow earthquakes have been discovered around the subduction zones of the Pacific rim very close to megathrust earthquakes. Investigating the lithosphere of the slow earthquake area versus non slow-earthquake area in subduction zones is crucial in understanding the role of the internal structure to control slow earthquakes. In this study, we investigate the lithospheric structure of stations in the slow earthquake area and non slow-earthquake areas in Chile using receiver function analysis and inversion method using teleseismic earthquakes. Here we focus on, especially the Vp/Vs ratios from both slow and non-slow earthquake areas, because the Vp/Vs ratio is sensitive to the fluid distribution in the lithosphere; the fluid distribution possibly controls the potential occurrence of slow earthquakes. Additionally, the nature of the slab can also play a crucial factor. The Vp/Vs ratio results across depth shows significantly higher value in the deeper oceanic slab region beneath the stations in the slow earthquake areas with higher contrast at the boundary.
Simulation of Monsoon trough and low pressure systems in CMIP6 models
Authors: Veluthedathekuzhiyil Praveen , Ravindran Ajayamohan , Cherumadanakadan Thelliyil Sabeerali
Published: March 2020

Monsoon low pressure systems (LPS) contributes to more than half of the Indian monsoon rainfall. However most climate models fail to capture the characteristics of low pressure systems realistically. This aspect is scrutinized in a wide range of available CMIP6 model simulations using an objective LPS tracking algorithm. Broader features such as monsoon trough over which these systems forms are also analyzed. It has been found that, majority of the models fail to realistically represent these two important features. However few models that were able to capture these events in CMIP5 are able to simulate them in CMIP6 as well. We examine the dynamical features that lead to realistic simulation of LPS in these set of models. Selected good models are then used to study the characteristics of LPS in a future warming scenario. This study will help in judging the performance of models and for any future improvements.
Spatial and temporal variations in ambient SO2 and PM2.5 levels influenced by Kīlauea Volcano, Hawai'i, 2007 - 2018
Authors: Whitty Rachel , Ilyinskaya Evgenia , Mason Emily , Wieser Penny , Liu Emma , Schmidt Anja , Roberts Tjarda , Pfeffer Melissa , Brooks Barbara , Mather Tamsin , Edmonds Marie , Elias Tamar , Schneider David , Oppenheimer Clive , Dybwad Adrian , Nadeau Patricia , Kern Christoph
Published: March 2020

The 2018 eruption of Kīlauea volcano, Hawai'i, resulted in enormous gas emissions from the Lower East Rift Zone (LERZ) of the volcano. This led to important changes to air quality in downwind communities. We analyse and present measurements of atmospheric sulfur dioxide (SO2) and aerosol particulate matter < 2.5 µm (PM2.5) collected by the Hawai'i Department of Health (HDOH) and National Park Service (NPS) operational air quality monitoring networks between 2007 and 2018; and a community-operated network of low-cost PM2.5 sensors on the Island of Hawai'i. During this period, the two largest observed increases in Kīlauea's volcanic emissions were: the summit eruption that began in 2008 (Kīlauea emissions averaged 5 – 6 kt/day SO2 over the course of the eruption) and the LERZ eruption in May-August 2018 when SO2 emission rates likely reached 200 kt/day in June. Here we focus on characterising the airborne pollutants arising from the 2018 LERZ eruption and the spatial distribution and severity of air pollution events across the Island of Hawai'i. The LERZ eruption caused the most frequent and severe exceedances of Environmental Protection Agency 24-hour-mean PM2.5 air quality thresholds in Hawai'i since 2010. In Kona, for example, there were eight exceedances during the 2018 LERZ eruption, where there had been no exceedances in the previous eight years as measured by the HDOH and NPS networks. SO2 air pollution during the LERZ eruption was most severe in communities in the south and west of the island, with maximum 24-hour-mean mass concentrations of 728 µg/m3 recorded in Ocean View (100 km west of the LERZ emission source) in May 2018. Data from the low-cost sensor network correlated well with data from the HDOH PM2.5 instruments (Kona station, R2 = 0.89), demonstrating that these low-cost sensors provide a viable means to rapidly augment reference-grade instrument networks during crises.
Interpretation of sedimentary subpopulations extracted from grain size distributions of loess deposits in the Sea of Azov, Russia
Authors: Chen Jie
Published: March 2020

Loess-paleosol sequences in eastern Europe, especially those at the Azov region, are among the sensitive terrestrial archives for past aeolian dynamics identification and paleoclimatic reconstruction within the Quaternary. Grain size analyses of loess sediments are widely used to interpret these transporting mechanisms and paleoclimatic changes, based on granulometric parameters and statistical decomposition methods. It is therefore of growing interest in the Earth Sciences and has been a major focus of sedimentary studies. Here, we present the unmixing grain size distribution results of a loess-paleosol section by jointly applying the standard deviation method and the end-member modeling in the Sea of Azov, Russia. The results indicated that two methods can produce the similar result on grain size decomposition, while the end-member modeling has advantage on quantitative and objective character. In addition, three main loess subpopulations or end-members with mode sizes of 8 μm, 18 μm and 32 μm respectively which represent distinct aerodynamic environments are identified from the grain size distribution in the Azov region. Thereinto, EM1 with mode size of 8 μm is the integrative result of combining atmosphere circulation with other environmental processes. EM2 with mode size of 18 μm is inferred to represent continuous background dust under non-dust storm conditions. EM3 with mode size of 32 μm is fraction that being transported in short-term, low-altitude suspension clouds during dust storm outbreaks. Of the three EMs, EM1 and EM2 have multiple origins due to their complex formation, whereas EM3 are primarily derived from the alluvial plains of different rivers in the Sea of Azov.
High resolution solar atlas for Greece under climate change
Authors: Markantonis Iason , Politi Nadia , Vlachogiannis Diamando , Gounaris Nikolaos , Stylianos Karozis , Athanasios Sfetsos
Published: March 2020

Renewable energy (RE) is considered as the most attractive and climate friendly source of energy to mitigate GHG effects. Due to the inherent, “non stationary” nature of climate, it is of paramount importance to be able make risk-informed decisions considering also the future conditions when installing / operating RES in Greece. As the amount of solar energy falling on the earth’s surface is highly influenced by local and large scale atmospheric movement conditions, high resolution simulations should be used to calculate it.

The aim of this research is to generate a climatology atlas of mean yearly and seasonal values for the GHI for the “historic time period” 1980-2009 and compare it against future values in 2020-2050. The current study employs high resolution downscaled climate model data to generate future solar radiation atlases for Greece based on RCP4.5 and RCP8.5 scenarios. Greece is a country with high potential in renewable solar energy. Several studies have mentioned the high amount of sunshine hours in most parts of the country, (e.g. Matzarakis & Katsoulis, 20061, HNMS2).

The data for both historic and future period analyses are produced from WRF 5km downscaled model output with temporal resolution of 6 hours, using as input ERA-INTERIM and EC-EARTH input data, respectively. The study that has produced the atmospheric model dataset is described in Politi, et al. (2018)3. We explore spatio-temporal changes of the GHI climatology and identify those areas which will exhibit considerable changes in the future.

References:

(Matzarakis & Katsoulis, 2006), ‘Sunshine duration hours over the Greek region’. Theoritical and Applied Climatology.

HNMS, ‘Greece Climate Atlas’. http://climatlas.hnms.gr/sdi/

(Politi, N. et al. 2018) ‘Evaluation of the AWR-WRF model configuration at high resolution over the domain of Greece’. Atmospheric Research Volume 208, 1 August 2018, Pages 229-245.

Acknowledgments
This work was supported by computational time granted from the Greek Research & Technology Network (GRNET) in the National HPC facility – ARIS - under project ID HRCOG (pr004020).
High viscosity of polymer solutions supports life in soil hotspots
Authors: Carminati Andrea , Benard Pascal , Zarebanadkouki Mohsen , Ahmed Mutez A
Published: March 2020

Plant roots and bacteria alter the soil properties by releasing a polymeric blend of substances (e.g. mucilage and extracellular polymeric substances EPS). Despite extensive knowledge of their ecological importance, the physical mechanisms by which these polymers alter the spatial configuration of the liquid phase and the related hydraulic and biogeochemical properties remain unclear.

Here we show that upon drying in porous media polymer solutions form one-dimensional filaments and two-dimensional interconnected structures spanning across multiple pores. Unlike water, primarily shaped by surface tension, these structures remain connected upon drying thanks to their high viscosity. The integrity of one-dimensional structures is explained by the high viscosity and low surface tension of the polymer solutions (elegantly characterized by the Ohnesorge number). The formation of two-dimensional structures requires consideration of the interaction of the polymer solution with the solid surfaces and external drivers, such as the drying rate.

The implications of these physical processes for life in soils are manifold. After their deposition they enhance water retention by acting as a new solid matrix delaying the air entry, they maintain the connectivity of the liquid phase, thus enhancing the unsaturated hydraulic conductivity, diffusion and enzyme activity. Upon rewetting, the formation of extensive two-dimensional structures corresponds to a sudden increase in soil water repellency, which reduces the rewetting kinetics and maintains gas diffusion preventing sudden water saturation. In summary, these structures buffer fluctuations in soil water contents, protecting roots and soil microorganisms against severe drying and sudden rewetting in soil hotspots.
Development of irrigation management services based on integration of innovative soil moisture monitoring and hydrological modelling
Authors: Pisinaras Vassilios , Brogi Cosimo , Bogena Heye , Hendricks-Franssen Harrie-Jan , Dombrowski Olga , Panagopoulos Andreas
Published: March 2020

The H2020 ATLAS project (www.atlas-h2020.eu/) aims to develop an open, flexible and distributed platform that will provide services for the agricultural sector based on the seamless interconnection of sensors and machines. Two interconnected services that will be included in the platform are the soil moisture monitoring and the irrigation management services. The soil moisture monitoring service will integrate both invasive (wireless sensor network (SoilNet)) and non-invasive soil moisture monitoring methods (cosmic-ray neutron sensors (CRNS)). Ultimately, a model will be developed that combines SoilNet and CRNS measurements to predict soil moisture time series. Soil water potential sensors will be incorporated as well.

Data provided by the above described service will be incorporated in an irrigation management service which will be based on hydrological modelling. The fully distributed, deterministic Community Land Model (CLM, version 5) will be applied which incorporates physically-based simulation of soil water balance and crop growth. Two different levels of application will be considered, namely the farm and watershed scale, which will be combined to weather forecast in order to provide irrigation scheduling advice. The farm scale application will take advantage of soil moisture monitoring data and provide farm specific irrigation scheduling, while the watershed scale application will provide a more generic irrigation advice based on the average cultivation practices. Furthermore, the CLM model will be coupled to a groundwater flow model in order to connect irrigation to groundwater availability. By doing so, it will be possible to support the efficient and sustainable groundwater management as well as competent water uses in an area that suffers from water scarcity.

These services will be implemented in the area of Pinios Hydrologic Observatory, located in central Greece. Three pilot orchards will be established introducing different soil moisture monitoring setups, while the boundaries of the Observatory will be used for the pilot implementation of irrigation management service on the watershed scale. Furthermore, two pilot vineyards located in northern Greece will be established in order to further test the services functionality on the farm scale.
Onset of the rainy season: a paradigm shift for conservation of the Amazon
Authors: Heil Costa Marcos
Published: March 2020

It has been recently demonstrated that large-scale mechanisms interact with Amazon deforestation to delay the onset and decrease the duration of the rainy season in Southern Amazonia. A short rainy season increases the exposure of the rainforest to drought and possibly fires, but also increases the climate risk to the intensive double cropping (soy/maize) agriculture system practiced in the region, which requires at least 200 days of rains. Here we show that areas in Southern Amazonia that have more than 20% deforestation, i.e., areas that have not respected the maximum deforestation allowed by Brazil´s Forest Code, have increased climate risk for agriculture when compared to areas that have less than 20% deforested. These results show how environmentally sensible the Brazilian Forest Code is. The legislation, if strictly followed, supports the climate regulation service provided by the rainforest, in a way that benefit the farmers that collectively respect the legislation by anticipating the onset and increasing the duration of the rainy season and decreasing the climate risk to the double cropping systems. These results introduce a new paradigm for conservation of the Amazon, in which there are economic and social reasons to preserve the native vegetation, and it is in the best interest of the agribusiness, local governments and people, to conserve and restore the remaining natural vegetation.
Usability of velocities of GNSS campaign measurements on volcano monitoring depending distance between station and volcano
Authors: Turen Zafer , Turen Yener , Erol Tuna
Published: March 2020

GNSS campaign measurements are often used for also volcano monitoring. The most important reason for this is that the permanent stations near the volcano are costly and likely to be damaged after the eruption. Often, even campaign measurements are risky near an active volcano. On the other hand, it would be low risky and low costly to make campaign measurements distant from volcano activities and eruptions. In this study, in order to expound the analysis results, we constituted our global test area using five IGS stations around five active volcano eruptions over 2019 via the Smithsonian Institute Global Volcanism Program. The data archives of the International GNSS service (IGS) and the time series of the Jet Propulsion Laboratory (JPL) were used for the purpose. And then we decimated the continuous data down to monthly and four monthly sampled GPS campaign time series. We also generated random values of ±3 mm for possible antenna setup errors. We tested whether the velocities obtained from monthly and four monthly solutions differ signiﬁcantly from the velocities derived from daily solutions. As a result, we concluded on monthly velocities that horizontal components are compatible completely and 80% of the vertical components are compatible. We also concluded on four monthly velocities that 65% of the horizontal components are compatible and vertical components are compatible completely. We explained the utilization of campaign measurements in volcano monitoring by examining the effect of the distance between the stations and volcanoes on the results obtained.

Keywords: Volcano Monitoring, GNSS Campaign Measurements.
Assessment on the wind hazard of tropical cyclones over the Northwest Pacific basin with parametric wind field model
Authors: Guo Cunmin , Fang Weihua
Published: March 2020

Strong winds over the sea surface induced by tropical cyclones (TCs) of Northwest Pacific (NWP) basin have been posing great threats to maritime activities, and quantitative assessment on its hazard intensity is of great importance. In the past, most studies focused on the modeling of winds over the land and areas of major island areas numerically or statistically. However, there is no systematic assessment of TC wind hazard over the NWP basin with long-term wind time series based on windfield modeling of historical TC events. In this study, the footprints of historical TC events during 1949~2019 were modeled based on the parametric models developed in previous studies, which simulate the winds of both gradient layer and planetary boundary layer. The historical TC track data were obtained from the China Meteorological Administration, and the wind records from the Global Telecommunication System (GTS) data were used for the calibration and validation of the models. The spatial resolution of the modeling output is 1km for winds over the sea surface. In order to reflect wind speed heterogeneity over the land of small islands, the wind speeds were modeled with 90-meter resolution by considering local terrain effects and roughness heights of islands, derived from 90m SRTM DEM data and 30m land-used data. Based on the simulated wind footprints of the 2384 TC events during 1949~2019, the relationships between wind intensity and frequency of each modeling pixel were analyzed and fitted with General Extreme Value (GEV) distribution. A series of wind hazard maps, including wind speeds for return periods of 5a, 10a, 20a, 50a and 100a, and the exceedance probabilities of wind scales from 10 to 17, etc were produced. These wind hazard maps are useful to the management of TC disaster risks in the NWP basin.
Interplay between water adsorption and viscosity determines the spatial configuration of EPS during soil drying
Authors: Carminati Andrea , Benard Pascal , Schepers Judith , Crosta Margherita , Zarebanadkouki Mohsen
Published: March 2020

Bacteria alter the physical properties of soil hotspots by secreting extracellular polymeric substances EPS. Despite the biogeochemical importance of these alterations is well accepted, the physical mechanisms by which EPS shapes the properties of the soil solution and its interactions with the soil matrix are not well understood.

Here we show that upon drying in porous media EPS forms one-dimensional filaments and two-dimensional interconnected structures spanning across multiple pores. Unlike water, primarily shaped by surface tension, EPS remains connected upon drying thanks to its high extensional viscosity. The integrity of one-dimensional structures is explained by the interplay of viscosity and surface tension forces (characterized by the Ohnesorge number), while the formation of two-dimensional structures requires consideration of the interaction of EPS with the solid surfaces and external drivers, such as the drying rate. During drying, the viscosity of EPS increases and, at a critical point, when the friction between polymers and solid surfaces overcomes the water adsorption of the polymers, the concentration of the polymer solution at the liquid-gas interface increases asymptotically and the polymers can no longer follow the retreating gas-water interface. At this critical point the polymers do not move any longer and are deposited as two-dimensional surfaces, such as hollow cylinders or interconnected surfaces. EPS viscosity, specific soil surface and drying rates are the key parameters determining the transition from one- to two-dimensional structures.

The high viscosity of EPS maintains the connectivity of the liquid phase during drying in soil hotspots, such as bacterial colonies, the rhizosphere and biological soil crusts.
Optical Properties of Secondary Organic Aerosol from Nitrate Radical Oxidation of Biogenic Volatile Organic Compounds: The Role of Highly Oxygenated Organic Nitrates  
Authors: Rudich Yinon , He Quanfu , Laskin Alexander , Brown Steve
Published: March 2020

Nitrate radical (NO3) oxidation of biogenic volatile organic compounds (BVOCs) represents one of the most important interactions between anthropogenic emissions related to combustion and natural emissions from the biosphere. The functionalization process during this oxidation process leads to the formation of multifunctional compounds such as organic nitrates (ON). ON account for a significant fraction of total organic aerosols (OA) in ambient air, which influence atmospheric chemistry process, air quality, and climate through regional and global budgets for reactive nitrogen (particularly ON), ozone, and OA formation. Despite the significance of this process in atmospheric chemistry, the climatic effect of SOA from this process is undefined, largely due to a lack of knowledge about their optical properties with respect to their chemical composition. In this study, we generated SOA from NO3 radical oxidation of a series BVOCs including isoprene, monoterpenes, and sesquiterpenes followed by photo-chemically aging in oxidation flow reactor (OFR/PAM). The chemical composition of the SOA was characterized online by high-resolution time-of-flight mass spectrometer (HR-Tof-AMS) and off-line by ultra-high-performance liquid chromatography (HPLC) coupled with photodiode array (PDA) detector coupled to a high-resolution Orbitrap mass spectrometer with a standard electrospray ionization (ESI) source (HPLC-PDA-HRMS). The UV-visible wavelength-resolved refractive index of the SOA, which is essential to understand their radiative forcing, was retrieved by measuring the light extinction using a novel broadband cavity-enhanced spectrometer (BBCES, 315-700 nm). We found that the SOA contain a large fraction of highly oxygenated ON, consisting of monomers and oligomers with single and multiple nitrate groups, which formed through bimolecular and unimolecular reactions. Strong absorption was detected in the UVA range which was attributed to the ON. The influence of the initial BVOCs/NO3 ratio and the transition from nighttime oxidation to daytime aging on the SOA optical properties will be discussed. We will highlight the link between the SOA optical properties evolution and the chemical composition transformation with respect to the highly oxygenated ON formation and its atmospheric fate upon daytime photochemical aging.
Climate-dependent propagation of precipitation uncertainty into the water cycle
Authors: Fallah Maraghi Ali , Oh Sungmin , Orth Rene
Published: March 2020

Precipitation is a crucial variable for hydro-meteorological applications. Unfortunately, rain gauge measurements are sparse and unevenly distributed, which substantially hampers the use of in-situ precipitation data in many regions of the world. The increasing availability of high-resolution gridded precipitation products presents a valuable alternative, especially over gauge-sparse regions. Nevertheless, uncertainties and corresponding differences across products can limit the applicability of these data. This study examines the usefulness of current state-of-the-art precipitation datasets in hydrological modeling. For this purpose, we force a conceptual hydrological model with multiple precipitation datasets in >200 European catchments. We consider a wide range of precipitation products, which are generated via (1) interpolation of gauge measurements (E-OBS and GPCC V.2018), (2) data assimilation into reanalysis models (ERA-Interim, ERA5, and CFSR) and (3) combination of multiple sources (MSWEP V2). For each catchment, runoff and evapotranspiration simulations are obtained by forcing the model with the various precipitation products. Evaluation is done at the monthly time scale during the period of 1984-2007. We find that simulated runoff values are highly dependent on the accuracy of precipitation inputs, and thus show significant differences between the simulations. By contrast, simulated evapotranspiration is generally much less influenced. The results are further analysed with respect to different hydro-climatic regimes. We find that the impact of precipitation uncertainty on simulated runoff increases towards wetter regions, while the opposite is observed in the case of evapotranspiration. Finally, we perform an indirect performance evaluation of the precipitation datasets by comparing the runoff simulations with streamflow observations. Thereby, E-OBS yields the best agreement, while furthermore ERA5, GPCC V.2018 and MSWEP V2 show good performance. In summary, our findings highlight a climate-dependent propagation of precipitation uncertainty through the water cycle; while runoff is strongly impacted in comparatively wet regions such as Central Europe, there are increasing implications on evapotranspiration towards drier regions.
Acoustic remote sensing monitoring of morphological and sedimentological seabed evolution of small and medium-scale French estuaries
Authors: Michel Guillaume , Le Bot Sophie , Lesourd Sandric , Lafite Robert
Published: March 2020

Estuarine benthic habitat quality health is integrated within the framework of the EU Water Directive and Marine Strategy Framework Directive. The long-term monitoring of small and medium-scale estuarine benthic habitat is based on recurrent observation of several factors, mainly bathymetry and seabed nature. Numerous studies have already addressed the performance and limitations of acoustic remote sensing and mapping techniques. However, most of these studies are limited to the marine and coastal domains and do not include the estuarine domain. Estuaries are considered as transitional domains, with various seabed morphologies (from rocky reefs to hydraulic dunes with anthropic modification overlap) and subtle granulometric variations of the seabed nature.

The objectives of our study are to explore the mapping performance of several acoustic remote sensing techniques and to determine which physical factors are the most representative of morphological and sedimentological characteristics of subtidal estuarine environment and of its evolution. The exploration of these cartographic variables has been performed for three small and medium-scale French estuaries: the Orne estuary, the Baie de Somme and the Belon estuary. These estuaries have been chosen to cover different morphological and sedimentological estuarine contexts.

Firstly, we evaluate the capacity of the main variables derived from bathymetry (slope, curvature, ruggedness) to map seabed morphology. We extend the variable exploration to the “Terrain Variable” GIS category and BTM (Benthic Terrain Modeler Toolbox) as well. Secondly, we explore the capacity of several cartographic variables, extracted from bathymetric, seabed acoustic backscatter and acoustic ground discrimination system (i.e. RoxAnn©), to map seabed sediment characteristics and variations. The seabed nature mapping is validated with ground truthing data, namely grab samples and seabed video profiles. Moreover, quantitative (D90, roughness, sorting) and qualitive information (apparent roughness of the seabed, benthic habitat) are extracted from the grab samples and seabed video profiles, respectively. The capacity of these variables to produce seabed nature maps is also explored.

Mapping results on the three areas are compared, in terms of mapping precision and reproducibility, and transposed into recommendations for small and medium-scale estuaries monitoring. The next step of the AUPASED project is he exploration of image analysis and machine learning classifications and their comparison to manual morphological and sedimentological maps produced.

The AUPASED project is funded by the AFB (French Agency for Biodiversity) as part of a convention between the AFB and the CNRS (UMR 6143, M2C).
Open Source Platform for Federated Spatiotemporal Analysis
Authors: Huang Thomas
Published: March 2020

In recent years, NASA has invested significantly in developing an Analytics Center Framework (ACF) to encapsulate the scalable computational and data infrastructures and to harmonize data, tools and computation resources to enable scientific investigations. Since 2017, the Apache’s Science Data Analytics Platform (SDAP) (https://sdap.apache.org) has been adapted by various NASA-funded projects, including the NASA Sea Level Change Portal, GRACE and GRACE-FO missions, the CEOS Ocean Variables Enabling Research and Applications for GEO (COVERAGE) Initiative, etc. With much of existing approaches to Earth Science analysis are focusing on collocating all the relevant data under one system, running on the cloud, this open source platform empowers the global data centers to take on a federated analytics approach. With the growing community of SDAP centers, it is now possible for researcher to interactively analyze observational and model data hosted on different centers without having to collocate or download data to their own computing environment. This talk discusses the application of this professional open source big data analytics platform to establish a growing community of SDAP-based ACFs to enable distributed spatiotemporal analysis from any platform, using any programming languages.
Prism-based Broadband Optical Cavity (400 – 1600 nm) for High-Sensitivity Trace Gas Sensing by Cavity Enhanced Absorption Spectroscopy
Authors: Chen Weidong , Wang Gaoxuan , Meng Lingshuo , Gou Qian , Yalin Azer , Nguyen Ba Tong , Coeur Cécile , Tomas Alexandre
Published: March 2020

The use of high reflectivity dielectric mirrors to form a high finesse optical cavity allows one to achieve long optical path lengths of up to several kilometres for high-sensitivity spectroscopy applications [1]. However, the high reflectivity of a dielectric mirror is achieved via constructive interference of the Fresnel reflection at the interfaces produced by multilayer coatings of alternate high and low refractive index materials. This wavelength-dependent coating limits the bandwidth of the mirror's high reflectivity to only a few percent of the designed central wavelength [2].

In this paper, we report on the development of a novel optical cavity based on prism used as cavity reflector through total internal reflection combined with Brewster angle incidence [3], which offers a high-finesse optical cavity operating in a broadband wavelength region from 400 to longer than 1600 nm. Cavity Enhanced Absorption Spectroscopy (CEAS) of NO2, NO3, and H2O vapor was applied to determine the achieved prism reflectivity over a broad spectral range from 400 nm to 1600 nm.

Experimental details and preliminary results will be presented. The developed prism-based cavity is specifically adapted for the needs of broadband measurement of multi-molecular absorber or/and wavelength-dependent extinction coefficient of aerosols over a broad spectral region.

Acknowledgments. This work is supported by the French national research agency (ANR) under the CaPPA (ANR-10-LABX-005), the MABCaM (ANR-16-CE04-0009) and the MULTIPAS (ANR-16-CE04-0012) contracts. The authors thank the financial support from the CPER CLIMIBIO program.

REFERENCES

[1] S. S. Brown, "Absorption spectroscopy in high-finesse cavities for atmospheric studies", Chem. Rev. 103 (2003) 5219-5238.

[2] G.R. Fowles, Introduction to Modern Optics, 2nd ed. (Rinehart and Winston, 1975), p. 328.

[3] B. Lee, K. Lehmann, J. Taylor and A. Yalin, "A high-finesse broadband optical cavity using calcium fluoride prism retroreflectors", Opt. Express 22 (2014) 11583-11591.
PFDHA modelling based on new empirical regressions for distributed faulting on dip-slip earthquakes
Authors: Nurminen Fiia , Baize Stéphane , Boncio Paolo , Pace Bruno , Scotti Oona , Valentini Alessandro , Visini Francesco
Published: March 2020

Probabilistic fault displacement hazard analysis (PFDHA) is needed for a numerical estimate of the displacement likely to occur at a site near an active fault in case of a surface faulting earthquake. The methodology is based on parameters describing the probability of occurrence, and the spatial distribution of the displacement on and off-fault. The methodology was created for normal faulting setting, and has been later complemented with the parameters for other slip types, especially regarding the principal fault rupturing. Based on empirical fault displacement data in the Worldwide and Unified Database of Surface Ruptures (SURE), we are presenting new regression parameters for distributed faulting for dip-slip earthquakes. The parameters are used in a computational model for assessing the surface rupture hazard near active dip-slip faults. The modelling results the probability distribution of exceeding a chosen level of displacement, and can be used in stcture design and land-use related decision making in areas where surface faulting hazard should be considered.
Quantitative comparison of measured and simulated O4 absorption for one day with extremely low aerosol load over the tropical Atlantic
Authors: Wagner Thomas , Dörner Steffen , Donner Sebastian , Beirle Steffen , Kinne Stefan
Published: March 2020

Measurements of the atmospheric absorption of the oxygen dimer O4 are often used to characterize the atmospheric light paths, e.g. to derive properties of clouds and aerosols. Some recent studies indicated discrepancies between measurements and simulations of the atmospheric O4 absorption, while others found exact quantitative agreement. One difficulty in these studies was to correctly represent the aerosol properties in the radiative transfer simulations, e.g. due to lack of information about the vertical profiles or scattering properties.

In this study we investigate MAX-DOAS measurements of the atmospheric O4 absorption during a ship cruise in April and May 2019 over the tropical Atlantic. The elevation angle of the instruments telescope is automatically stabilized in order to compensate the motion of the sea. We select measurements on one day (2 May 2019) with extremely low aerosol optical depth (between about 0.03 and 0.05 at 360 nm). For such conditions the atmospheric scattering processes are dominated by Rayleigh scattering on air molecules.

Besides the MAX-DOAS measurements, also measurements by a ceilometer and sun photometer are available, which are used to constrain the atmospheric aerosol properties. The radiative transfer simulations are carried out with the full spherical radiative transfer model MCARTIM.
The in-situ stress state of the Rhine-Ruhr region and its implications for the geothermal energy utilization
Authors: Kruszewski Michal , Montegrossi Giordano , Backers Tobias , Saenger Erik
Published: March 2020

The Rhine-Ruhr region is one of the largest metropolitan areas in Europe, with more than 10 million inhabitants, located in western Germany. The region is defined by the rich coal-bearing layers from the upper Carboniferous period, extracted as early as the 13th century and belonging to the sub-Variscan Trough. In 2018, after more than 700 years of exploration, the last black coal mine was closed in the area. One of the most promising re-uses of the abandoned coal mines is the exploitation of geothermal energy sources. Additionally, to the geothermal energy extracted from existing mines, potential deep geothermal reservoirs within the Rhine-Ruhr, may exist at depths between 4.5 and 6 km, where Devonian limestones were found. Based on the available temperature profiles from deep exploration wells in the area, geothermal gradient amounts to 36.8oC/km and results in reservoir temperatures between 170oC and 220oC, which will enable not only heat but even electricity production. This study provides a comprehensive investigation of the full in-situ stress state tensor with its anisotropy and presents crucial physical formation and natural fracture properties. The data for this investigation was acquired from the extensive borehole logging and geomechanical campaigns carried out in deep coal exploration wells throughout the 1980s as well as from the recent shallow geothermal research wells. Acquired data allowed assessing critically-stressed, i.e. hydraulically active, fractures undergoing shear displacement, being primarily responsible for the future geothermal reservoir permeability. Extensive sets of microseismic, subsidence and drilling data were used to confirm the results of the analysis. Additionally, wellbore stability analysis and potential drill paths for the future medium-to-deep geothermal wells in the region were assessed. This study is a part of the 3D-RuhrMarie project, which aims to assess the intrinsic seismic risk within the Rhine-Ruhr region to promote safer and economically more efficient exploration and exploitation of the future geothermal resources.
Chemical evidence for the preservation of collagen in Eocene turtle shell using Py-GCxGC-TOFMS
Authors: Umamaheswaran Raman , Dutta Suryendu , Singh Hukam , Kumar Sumit , Sahni Ashok
Published: March 2020

Studies on organic preservation in fossil tissues have been a contentious topic, as fossils have been thought to preserve little, if any, organic content after diagenesis. Several studies have previously reported the presence of collagen in fossils from deep time including in Cretaceous dinosaur bones (e.g.: Schweitzer et al., 2007, Science v. 316, 277-280). These findings have also been the subject of criticism with respect to the reproducibility of their results (e.g.: Buckley et al., 2017, Proceedings of the Royal Society B v. 284: 20170544). In the present study, we analysed a turtle shell from Eocene to ascertain a suitable proxy for the preservation of collagen, by using comprehensive pyrolysis gas chromatography – time-of-flight mass spectrometry (Py-GCxGC-TOFMS) and comparing the pyrolytic products obtained to those of modern turtle shell and collagen standard. 

In order to add to the robustness of the study, industry standards of chitin, melanin and collagen were analysed using Py-GCxGC-TOFMS and their chromatograms compared for characteristic pyrolytic products that can be used to differentiate between them. Collagen could be differentiated from the other nitrogen-bearing biopolymers based on the presence of characteristic cyclic dipeptides known as 2,5-diketopiperazines (DKPs) which are formed by the recombination of peptides during pyrolysis. We compared the chromatogram of collagen standard to that of a modern turtle shell and found that the two chromatograms could be correlated based on the presence of diketodipyrrole, 2,5-DKP(Pro-Pro), 2,5-DKP(Pro-Ala), 2,5-DKP(Pro-Gly), 2,5-DKP(Pro-Hyp), 2,5-DKP(Pro-Arg) and 2,5-DKP(Pro-Lue/Ile). We then compared the chromatogram of modern turtle shell to the Eocene shell and confirmed the presence of diketodipyrrole and 2,5-DKP(Pro-Pro) in the fossil shell thus unambiguously indicating that collagen is preserved.
Rotation and Strain Instrument Performance Tests with Active Seismic Sources
Authors: Bernauer Felix , Wassermann Joachim , Behnen Katrin , Igel Heiner , Donner Stefanie , Edme Pascal , Sollberger David , Paitz Patrick , Igel Jonas , Izgi Gizem , Eibl Eva P.S. , Buske Stefan , Veress Christian , Guattari Frederic , Sebe Olivier , Brunner Basil , Kurzych Anna T. , Bonkovsky Piotr , Bobra Piotr , Brokesova Johana ,   Fürstenfeldbruck Experiment Team
Published: March 2020

Interest in measuring seismic rotation and strain is growing in many areas of geophysical research. This results in a great need for reliable and field deployable instruments measuring ground rotation and strain. To further establish a high quality standard for rotation and strain measurements in seismology, researchers from the Ludwig-Maximilians University of Munich (LMU), the German Federal Institute for Geosciences and Natural Resources, the University of Potsdam and the ETH Zürich organized a comparative sensor test experiment which took place in November 2019 at the Geophysical Observatory of the LMU in Fürstenfeldbruck, Germany. More than 40 different sensors such as ring-laser and fiber optic gyroscopes, a Distributed Acoustic Sensing (DAS) cable and interrogator, liquid-based as well as mechanical rotation sensors were involved in addition to 12 classical broadband
seismometers and a 80 channel, 4Hz geophone chain. The experiment consisted of two parts: during the first part, the sensors were co-located in a huddle test recording self noise and signals from small, nearby explosions. In a second part, the sensors were distributed into the field in various array configurations recording active seismic signals generated by small amounts of explosive and a vibro-seis truck. This contribution presents details on the setup of the experiment and first results on sensor performance characteristics and signal similarities.
3-D lithospheric-scale rheological model of the Sea of Marmara
Authors: Gholamrezaie Ershad , Scheck-Wenderoth Magdalena , Bott Judith , Heidbach Oliver , Bohnhoff Marco , Strecker Manfred R.
Published: March 2020

The North Anatolian Fault (NAF) below the Sea of Marmara, also known as the Main Marmara Fault (MMF), has repeatedly produced major (M>7) earthquakes in the past. Currently, the MMF corresponds to a seismic gap between the locus of the most recent M>7 ruptures of the 1912 Ganos (M 7.3) and 1999 Izmit (M 7.4) earthquakes. This seismic gap has a recurrence time of approximately 250 years and has not ruptured since 1766. Consequently, it poses a major seismic hazard to the Marmara region, including the megacity Istanbul. The Marmara seismic gap is considered to be locked in the eastern and central segments of the MMF, while the western segment is partly creeping. In the context of seismic hazard and risk assessment, one of the main questions is, if either the Marmara seismic gap will rupture in a single large earthquake or in several ones due to segmentation along the MMF. In part this depends on the physical properties of the lithosphere below the Sea of Marmara as they are a key control of the contemporary stress state. To contribute to this discussion, we present 3‑D lithospheric-scale thermal and rheological models of the Sea of Marmara. These models are based on published 3‑D density models that indicate lateral and vertical crustal heterogeneities below the Sea of Marmara (Gholamrezaie et al., 2019). The density models consist of two layers of sediments, upper and lower crystalline crustal layers, and two crustal dome-shaped, high-density bodies that spatially correlate with major bends along the MMF. We show that these crustal heterogeneities may cause the lithospheric strength to vary significantly along the MMF, supporting the hypothesis that the fault is mechanically segmented. In addition, our results indicate a spatial correlation between observed aseismic fault patches (Wollin et al., 2018) and the location of the high-density bodies. These bodies are colder and stronger than the surrounding crystalline crust, and may thus represent the lateral bounds of the locked MMF segment.
Heat Wave Impact Forecast by Analysis of Vulnerability and Exposure over Daegu Metropolitan City and Gyeongsangbuk-do Province
Authors: Kim Suin , Kim Byungchoon
Published: March 2020

It is gradually increasing that the scale of economical and social damage caused by recent risk meteorological phenomena. The aspect of damage due to heat wave and cold wave as well as heavy rain, typoon, heavy snow are getting complicated. So the demand for customized information to protect the lives and property of the people has also been increasing constantly. Daegu Metropolitan City and Gyeongsangbuk-do Province are especially the area where heat wave occurs most frequently in south Korea. In addittion, as global warming has been accelerated recently, there are growing concerns that heat-related patients and livestock mortality increase. Therefore, Daegu Regional Office of KMA(Korea Meteorological Administration) developed heat wave impact forecast services from 2016 to prevent and minimize damages from heat wave in our area and has been improving and operating the service as of 2019.

Daegu Regional Office of KMA’s Impact heat wave impact forecast is for reducing the damage caused by heat wave in our area in 2019. It is carried in 4 steps: Attention, Caution, Warning, Danger and in 7 field: Health, Stock Raising, Fish culture, Agriculture, Industry, Traffic and Electricity. We used the objective value such as the highest temperature and the number of days to last as the criteria for each stage of the health sector. Other sectors except health, we considered the risk level in the health sector basically and the level of risk was determined taking into account the vulnerability and exposure of each region. We analysed them of each region in detail in order to provide the correct contents. Finally, we were able to obtain a number of analysis results that linked to heat wave and various types of damage. Our services have been conveying to public by facsimile, E-mail as a document and is provided by KMA website(http://www.weather.go.kr). And we announced the information that we made about heat wave on YouTube.

As a result, our services seem to have positive impacts. The number of heat-related patients decreased by 47% from the previous year. After the service was provided, a questionnaire survey was conducted for recipient, and 84% of respondent gave positive outcome about our services.

Based on the studies and services, Daegu Regional Office of KMA is going to calculate a more objective risk level for other sector except health in order to play a role in future regional customization services. And we are going to reform the document of heat wave impact forecast to contain more information focused on our region.

 