bluuebunny/crossref_metadata_2025 huggingface dataset:
Assembly of optical fiber sensors for rotational seismology - data coherence and comparability issues in field application
Authors: Kurzych Anna , Jaroszewicz Leszek R. , Dudek Michał , Krajewski Zbigniew , Kowalski Jerzy K. , Niespodziany Sławomir , Bernauer Felix , Wassermann Joachim , Igel Heiner
Published: March 2020

Nowadays rotational seismology has become rapidly developing field of study which can deliver completely new  perspectives for earthquakes analysis or torsional effects in engineering structures. Rotational seismology as a scientific field has been clarified in 2009 as a field for researching all aspects of rotational ground movements generated by earthquakes, explosions, and ambient vibrations. Nevertheless, technical requirements for sensors in this field are very strict and rigorous, especially taking into account measuring range from 10-7 rad/s event up to few rad/s. In order to fulfill all technical requirements for sensors which can be applied in rotational seismology measurements we designed and constructed device based on an optical fiber gyroscope (FOG). Fibre-Optic System for Rotational Events&phenomena Monitoring (FOSREM) is a an interferometric optical fiber sensor designed to continuously observe rotational effects. It uses closed-loop configuration which is based on the compensatory phase measurement method as well as specific electronic system. It should be noticed, that the coupling of the FOSREM’s optical part which detects critical low value of signal with specialized electronic system which requires precise analog to digital conversion as well as data transfer with different sampling rate is the source of differences between constructed devices even in the same technology. In this paper we present laboratory investigation of FOSREMs including Allan variance analysis indicating that Angle Random Walk is equal to 10-7 rad/s. Expect laboratory verification of proper FOSREMs’ operation we carried out field tests taking into account that validity and reliability of the research instruments are crucial during field application. The quality of data utilised in any research determines the outcome of the research and its importance for further research work and relevance to scientific community and knowledge. The data reliability can be determined by comparison between records from several sensors. We present first data from international field research which was focused on efforts to achieve uniformity in collecting and data processing. This experiment involved more than 40 rotational and strain sensors and took place in Geophysical Observatory Fürstenfeldbruck, LMU Munich, Germany. Authors applied four FOSREMs in this experiment and the presented analysis was focused on their data comparability as well as consistency.
Multi-Scale Simulation of Hydraulic Fracturing and Production: Testing with Comprehensive Data from the Hydraulic Fracturing Test Site in the Permian Basin
Authors: Birkholzer Jens , Morris Joseph , Bargar John , Cihan Abdullah , Crandall Dustin , Deng Hang , Fu Pengcheng , Hakala Alexandra , Hao Yue , Jew Adam , Kneafsey Timothy , Lopano Christina , Molins Rafa Sergi , Nakagawa Seiji , Moridis George , Reagan Mathew , Settgast Randolph , Steefel Carl , Voltolini Marco
Published: March 2020

The Hydraulic Fracturing Test Site (HFTS) project, fielded a few years ago within the Wolfcamp Formation in the Permian Basin in the United States, provides an excellent opportunity to further develop our understanding of the geomechanical response to hydraulic stimulation and associated production in shale lithologies. In addition to a full set of geophysical and tracer observations, the project obtained core samples from wells drilled through the stimulated region, characterizing the propagation of fractures, reactivation of pre-existing natural fractures, and placement of proppant. In addition to providing an overview of the available field data from the field test, we describe here a multi-scale modeling effort to investigate the hydrologic, mechanical and geochemical response of the Wolfcamp Formation to stimulation and production. The ultimate outcome of this project is the application and validation of a new framework for microscopic to reservoir scale simulations, built upon a fusion of existing high performance simulation capabilities.

The modeling occurs across two spatial domains – the “reservoir scale”, which encompasses the intra- and inter-well regions, and the “inter-fracture scale”, which is the region between stimulated fractures. Physics-based simulations of the fracture network evolution upon stimulation at the reservoir scale using the simulator GEOS provide input for reservoir-scale production simulations conducted with the TOUGH family of codes. At the inter-fracture scale, the fluid dynamics and reactive transport Chombo-Crunch code is used simulate the micro-scale pore-resolved physical processes occurring at the fracture and rock interfaces upon stimulation and production, tested against laboratory studies of proppant transport and pore-scale reactions. Micro-scale modeling and imaging provides upscaled flow and transport parameters for larger-scale reservoir modeling and production optimization.
Influence of a multi-layered salt stratigraphy on rift-basin development; Insights from the Slyne and Erris basins, offshore NW Ireland
Authors: O'Sullivan Conor , Childs Conrad , Saqab Muhammad , Walsh John , Shannon Patrick
Published: March 2020

This study uses a combination of 2D and 3D seismic reflection surveys coupled with borehole data from the Irish Atlantic margin to map the distribution of salt in the Slyne and Erris basins and understand its influence on basin development throughout the Mesozoic.

The north-western European Atlantic margin is populated by a framework of rift basins stretching from the Barents Sea offshore northern Norway to the south of Portugal. Several of these basins contain significant quantities of salt, which plays an important role in basin development and structural evolution. While salt is present on the Irish Atlantic margin, its distribution and role in basin development is poorly understood. The Slyne and Erris basins, off the northern coast of Ireland, contain two proven layers of salt; the Upper Permian Zechstein Group and the Upper Triassic Uilleann Halite Member of the Currach Formation.

Where present in their salt-dominated forms, both layers act as décollements, mechanically detaching pre-, intra- and post-salt stratigraphy. The Zechstein Group is present throughout the Slyne and Erris basins, while the Uilleann Halite Member is only developed in the northern Slyne Basin and the southern Erris Basin. Both salt layers have undergone significant halokinesis during basin development, and their original thicknesses are unclear. This halokinesis has played a significant role in the formation of hydrocarbon traps in these basins: the Zechstein Group forms salt pillows and salt rollers, causing folding and rafting in the overlying Mesozoic section, driven by active faulting in the pre-salt Palaeozoic basement. The Uilleann Halite Member caused thin-skinned crestal collapse and delamination of the overlying Jurassic section above anticlines cored by Zechstein salt. Both layers of salt play a key role in the development of the Corrib gas field and are responsible for trap formation in the Corrib North and Bandon discoveries. Understanding the genesis of these salt-related structures in a multi-layered salt system will provide insight into future exploration activities in salt-prone basins offshore Ireland, as well as their suitability for storage of sequestered CO2.

ICRAG is funded in part by a research grant from Science Foundation Ireland (SFI) under Grant Number 13/RC/2092 and is co-funded under the European Regional Development Fund and by PIPCO RSG and its member companies.
Characteristics and interannual changes of ice cliffs on the debris-covered glaciers of HMA
Authors: Kneib Marin , Miles Evan , Buri Pascal , Pellicciotti Francesca
Published: March 2020

Ice cliffs have been shown to be key contributors to the mass balance of debris-covered glaciers in High Mountain Asia. They are zones of enhanced energy inputs and contribute to glacier melt 3 to 15 times more than the surrounding debris, with backwasting rates of up to 10 cm/day. Field observations have shown that these features can evolve quickly, extending by 50% of their area or being entirely reburied by debris within the course of one monsoon season, while others remain stable over several years. They can also appear suddenly via abrupt events such as englacial conduit collapse, crevasse opening or slope destabilization by supraglacial streams or ponds. These mechanisms and evolution patterns have never been quantified nor even observed at the scale of a glacier, mainly because very few repeat datasets of appropriate temporal resolution exist.

Here we combine one existing and new multi-temporal datasets of cliff outlines derived manually or semi-automatically, from debris-covered glaciers in four regions of HMA with varying topography, debris-cover and climatic regimes. We use a tracking algorithm to automatically detect the evolution of these features over several years, focusing on their formation rates and the evolution of their shapes and sizes obtained from high resolution digital elevation models. Surface velocity maps, debris thickness measurements and outlines of ponds and the main supraglacial streams are used to relate the evolution patterns to glacier dynamics and supraglacial hydrology.

We follow and analyze the inter-annual evolution of more than one thousand cliffs along with the nearby ponds. These results allow us to propose a classification of ice cliffs based on the mechanisms governing their genesis and evolution. Finally, we use this classification to map and quantify the different genesis mechanisms dominant at each of the four sites. By considering the evolution of each cliff independently, this study bridges the gap between large-scale statistical studies of cliff populations and detailed field observations focusing on a few features of specific glaciers. In addition to improving our general understanding of ice-cliff evolution, this study provides the first consistent and regional dataset of cliff characteristics, changes and patterns to support modeling of ice cliffs at a large scale.
Investigations on the power-law burst lifetime distribution characteristics of the magnetospheric system
Authors: Prasad Prince , Kumar G Santhosh , Gopinath Sumesh
Published: March 2020

The waiting time distributions and associated statistical relationships can be considered as a general strategy for analyzing space weather and inner magnetospheric processes to a large extent. It measures the distribution of delay times between subsequent hopping events in such processes. In a physical system the time duration between two events is called a waiting-time, like the time between avalanches. The burst lifetime can be considered as the time duration when magnitude of fluctuations are above a given threshold intensity.  If a characteristic time scale is absent then the probability densities vary with power-law relations having a scaling exponent. The burst lifetime distribution of the substorm index called as the Wp index (Wave and planetary), which reflects Pi2 wave power at low-latitude is considered for the present analysis. Our analysis shows that the lifetime probability distributions of Wp index yield power-law exponents. Even though power-law exponents are observed in magnetospheric proxies for different solar activity periods, not many studies were made to analyze whether these features will repeat or differ depending on sunspot cycle. We compare the variations of power-law exponents of Wp index and other magnetospheric proxies, such as AE index, during solar maxima and solar minima. Thus the study classifies the activity bursts in Wp and other magnetospheric proxies that may have different dynamical critical scaling features. We also expect that the study sheds light into certain stochastic aspects of scaling properties of the magnetosphere which are not developed as global phenomena, but in turn generated due to inherent localized properties of the magnetosphere.
The evolvement of anaerobic oxidation of methane in fresh water sediments
Authors: Vigderovich Hanni , Eckert Werner , Sivan Orit
Published: March 2020

Methane is a potent greenhouse gas that is produced naturally via microbial processes in anoxic environments (i.e. marine and lake sediments). The release of methane to the atmosphere from sediments is controlled by its aerobic and anaerobic oxidation. Anaerobic oxidation of methane (AOM) consumes up to 90% of the produced methane in marine sediments and over half of the produced methane in freshwater sediments. The most common electron acceptor in marine sediments for AOM is sulfate, however, in freshwater lake sediments, where sulfate concentrations are low, other electron acceptors can take its place (i.e. iron/manganese/nitrate). In lake Kinneret (Israel), iron-coupled AOM was evident by in-situ sedimentary profiles and in fresh sediment slurry incubations. Here we present geochemical and molecular analyses results of slurry experiments of long-term incubated lake Kinneret sediments with labeled 13C-methane, different potential electron acceptors and a few inhibitors. These experiments are part of an ongoing research to characterize the AOM processes in lake sediments, and indicate another possible type of AOM that has evolved in the long-term incubated lake sediments.
Complex investigation of Lake Bannoe sediments (South Ural, Russia)
Authors: Kuzina Diliara , Anastasia Yusupova , Danis Nurgaliev , Pavel Krylov , Vadim Antonenko , Bulat Gareev , Georgii Batalin
Published: March 2020

In paper presented results of complex investigations of Lake Bannoe (53°34'40.5"N 58°38'05.0"E) and its sediments. The origin of the Lake is tectonic. Seismoacoustic investigations were carried out for choose the best places for coring with continuous sedimentation and avoid gas saturated sediments. 4 long cores of sediments (up to 5.5 meters) were collected with using special hydraulic corer.

To study the sediments, a set of methods was used including petromagnetic and paleomagnetic studies, the study of mineralogical and elemental composition. According radiocarbon dating the maximum age of samples is 12.5 thousand. The age of samples increases with depth naturally, which means we have continuous sedimentation without hiatus.

Measurements of magnetic susceptibility (MS), hysteresis parameters and thermomagnetic analysis were carried out to determine changes in magnetic mineralogy and sedimentation conditions. Thermomagnetic curves measured on Curie express balance, coercitive parameters on J-coercivity spectrometer and magnetic susceptibility on multi-function kappabridge MFK1-FA (AGICO). The elemental composition was studied on an S8 Tiger X-ray fluorescence wave dispersion spectrometer. X-ray diffraction was performed on a Bruker D2 Phaser for studying mineralogical composition.

Changes in the magnetic susceptibility along the section are not significant, which indicates the constancy of sedimentation conditions. Only lower part, below 4.7 meters, MS increasing which corresponds to big input of terrigenous material. Most common magnetic minerals of sediments are pyrite and magnetite. Main minerals are quartz, albite, mica, from 1.3 meters and below in sediments detected calcite and dolomite.

Obtained data from all methods (magnetic properties, minerology, elemental composition) used for preliminary paleoclimatic and paleoenvironmental reconstructions of South Ural region for last 12.5 kyr. According petromagnetic data there is no big changes in sedimentation conditions. Also elemental composition shows the same, no big changes. Bottom part of sediments core are consist of more coarse material this is reflected both in magnetic properties and in elemental composition.

This work was funded by the Russian Science Foundation under grant № 18-17-00251.
Mobile MAX-DOAS and in situ measurements of atmospheric trace gases and aerosols
Authors: Wittrock Folkard , Krause Kai , Lange Kezia , Seyler André , Richter Andreas , Burrows John P.
Published: March 2020

As part of the German project MeSMarT (Measurements of shipping emissions in the marine troposphere, a cooperation between the University of Bremen and the German Federal Maritime and Hydrographic Agency) and the EU LIFE project CLINSH (Clean Inland Shipping,) numerous mobile measurements of atmospheric trace gases and aerosols have been carried out.

For both projects one main objective is to investigate the general impact of shipping emissions on the air quality in regions with high marine traffic. In order to do this in areas where no permanent monitoring systems are available, in 2015 a mobile lab has been set up, which includes among other instrumentation for air pollution and meteorological parameters a scientific-grade MAX-DOAS system as well as in situ instruments for nitrogen oxides, ozone, carbon monoxide and sulfur dioxide (trace level).

In this study we present intercomparison results between the different instruments onboard the mobile lab as well as the interpretation of the results using complementary data sets at different locations including the Lower Rhine and Waal area and several regions in Northern Germany. For some places close to the banks of the Rhine more than 70% of the nitrogen oxides are related to shipping emissions. Emission factors for different ship types have been calculated and compared to recent studies and emission inventories.
The role of inland freshwaters in summer CO2, CH4 and N2O emissions from northeast Siberian Arctic tundra
Authors: Martyn Melanie , Dean Joshua , Dolman Han , Vonk Jorien
Published: March 2020

Inland waters can be significant sources of greenhouse gases (GHGs; CO2, CH4 and N2O) to the atmosphere, yet they are often excluded from terrestrial GHG balances. Vast stocks of carbon stored in Arctic tundra permafrost soils are vulnerable to mobilisation due to permafrost thawing accelerated by the amplified effects of climate warming at high latitudes. The carbon that is released becomes available to (partial) degradation producing GHGs which inland waters emit to the atmosphere, thus forming a positive feedback to climate warming. Rising temperatures, longer summers and increased precipitation in the Arctic tundra are expected to increase permafrost thaw and degradation rates, therefore the contribution of inland waters to the tundra terrestrial GHG budgets needs to be better understood to assess the strength and timing of the feedback effect in the future.

Field data from lakes, ponds and streams throughout the summer season of three years and from floodplain water present in one of the years was collected. This data was used to calculate CO2 equivalent diffusive fluxes from inland freshwaters, and combined with eddy covariance flux tower measurements and with satellite remote sensing to calculate total GHG emissions of the study area.

The results indicate that ponds are the largest contributors to upscaled inland water GHG emissions (around 50%) followed by streams and finally lakes. Streams had the highest emission rates followed by lakes and ponds the lowest, however due to the large surface area coverage of ponds (15% of the study area) they become the largest contributor to the upscaled freshwater GHG emissions. Upscaling of CH4 and CO2 fluxes shows that while the study region remains a GHG sink, inclusion of freshwater emissions reduces its sink capacity by 28% during our reference month July. Assuming that 10% of the study area is flooded in this month, it reduces the terrestrial GHG sink estimate to 45% instead of 28%, partially due to N2O oversaturation in the flood water in relation to the atmosphere whereas N2O concentrations in lakes, streams and ponds are close to zero. Overall the results show that if the Siberian Arctic tundra becomes wetter or more frequently flooded due to climate warming it will significantly affect the total terrestrial GHG balance.
Proposed depositional scenarios of the Nise Formation on the Mid-Norwegian Continental Shelf, with focus on the Halten Terrace.
Authors: Hope Blå Maren , Felix Maarten , Watt Jeremy , Næss Arve
Published: March 2020

The Late Cretaceous Nise Formation is located on the Mid-Norwegian Continental Shelf. On the Halten Terrace, the formation is generally described as a mudstone interbedded with thin sandstones and carbonate stringers. The spatial distribution, connectivity, sediment source and depositional processes of the sandstones are uncertain. 

Six cores and associated thin sections of the Nise Formation on the Mid-Norwegian Continental Shelf have been described. Three of the cores are from the Halten Terrace area, and one core each are from the Vestfjorden Basin, Nyk High and the Møre/Vøring Basin transition respectively. The main focus has been on the Halten Terrace while the cores from the other areas (tens to hundreds of kilometres away from Halten) are included to compare facies, depositional environment, source of sediment, grade of bioturbation and other characteristics with those of the Halten Terrace.

An isochore map of the Nise Formation in the central part of the Halten Terrace has been constructed based on interpretation of wireline logs from approximately 280 well penetrations. The map reveals a distinct thickness increase in the central parts of the Halten Terrace, suggesting the infilling of a former sub-basin. Additionally, the map supports an eastern and/or northern sediment source, which might exclude the Greenlandic landmasses as a provenance area. The cores from the Halten Terrace, supported by additional wireline well logs, indicate that the upper parts of the formation contain a greater amount of sandstone facies compared to the lower parts. These sandstones are interpreted as densely bioturbated distal turbidites. The comparison of facies development in the cores from the different areas indicates variability in depositional systems between the areas at the time of deposition.

Different depositional scenarios of the Nise Formation on the Mid-Norwegian Continental Shelf are being developed in order to increase the understanding of the Nise Formation on the Halten Terrace. The proposed scenarios include various sediment input models and alternative depositional environments in the different areas. The scenarios mainly display marine, isolated systems. 
A reconstruction of paleoenvironments and climate change during the Late Holocene in Sierra Nevada: the organic and inorganic geochemistry record from the Borreguil de los Lavaderos de la Reina record (southern Iberian Peninsula)
Authors: López-Avilés Alejandro J. , García-Alix Antonio , Jiménez-Moreno Gonzalo , Toney Jaime L. , Anderson R. Scott
Published: March 2020

Remote small alpine lakes and wetlands from the Sierra Nevada mountain range (southern Spain) are exceptional ecological sensors of global change and preserve a complete post-glacial Holocene sedimentary record. Several organic and inorganic geochemical analyses carried out in the sedimentary record of the Borreguil de los Lavaderos de la Reina, a small bog located in the north face of the Sierra Nevada at 2421 m, have allowed us to reconstruct climate, vegetation and human interaction in the highest mountain range in southern Iberia in the last 3000 years. This study shows that during the Late Holocene there is a progressive climatic aridification, which produced a reduction in the aquatic environments in Sierra Nevada. The studied peat bog geomorphology and surrounding areas also conditioned the evolution of the local vegetation. An increasing trend in the detrital eolian input from northern Africa, as well as an important anthropic impact in the ecosystems (artificial drainage system among other activities) are observed in the studied record in the last century.
Estimating regional distributions of agricultural microplastic immissions into soils - a top-down modeling approach for Germany
Authors: Brandes Elke , Henseler Martin , Kreins Peter
Published: March 2020

The topic of microplastic (MP) contamination in agricultural soils has recently gained attention in science and society. Experimental studies indicate that microplastic (i.e., plastic particles < 5mm in size) can have negative effects on soil physical properties and ecology, but an actual impairment of soil functions at current concentration levels in agricultural soils has yet to be shown. Nevertheless, the continuous production of single-use plastic and low degradation rates implicate an accumulative effect of MP in the environment that calls for more research on the amounts and impacts of this contaminant.  The most discussed agricultural sources for microplastic contamination of cropland are biosolids (e.g., sewage sludge and compost) applied as soil amendment to fields, as well as tarps used in plasticulture. However, knowledge about how much microplastic is accumulating in agricultural soils is scarce. Only a few analytic quantification studies have been published so far. Existing estimates from production and consumption statistics have been performed at national level, but as of yet, spatially explicit regional quantification of microplastic immissions into agricultural soils are missing in the scientific literature.

Using data on microplastic concentrations in biosolids from the literature in combination with national and regional statistics on sewage sludge, compost and organic waste production, as well as specialty crop areas, we estimated annual microplastic immissions into agricultural soils in Germany at NUTS3 (county) resolution. This top-down modeling approach allowed us to identify hot spots where potential microplastic concentration is high. 

Although these estimates are based on limited data availability, they yield information on the spatial distribution of potential microplastic contamination in agricultural soils in Germany. Our results provide first indications about locations where detailed soil analysis could be useful to investigate in situ processes and impacts. The methodology can be applied to other regions and continuously adapted when more knowledge on relevant sources, transport, accumulation, and degradation rates of microplastic in soils is gained in the future. 
Mineralogical investigations on pozzolanic dolomitic lime mortars to assess the phase development at different curing conditions
Authors: Schidlowski Martin , Bader Tobias , Diekamp Anja
Published: March 2020

For a long time, historical mortars were primarily associated with mortars based on calcium carbonate as the main binder phase. Recent publications show that considerable amounts of magnesium are often present in the binder of historical mortars, which is referred to the use of dolomite rock as raw material (Diekamp, ​​2009; Diekamp, ​​2014). A special feature are Roman and medieval dolomitic lime mortars with the addition of brick fragments as a pozzolanic component (Schidlowski, 2019).In order to characterize the phase formation in modern pozzolanic dolomitic lime mortars, mortar prisms based on dolomitic lime were produced with three different pozzolans (antique and modern brick dust and metakaolin). To draw comparisons with other binders, identical prisms based on calcite and magnesite were produced. These specimens were stored under different environmental conditions (60 % and 95 % relative humidity) and examined by X-ray diffraction and simultaneous thermal analysis after periods of 28, 90 and 180 days.

The results obtained so far show that the binder phases that have evolved in the mortars based on dolomitic lime are calcite, aragonite, portlandite, brucite and AFm phases. Aragonite is only found in traces in the samples with metakaolin. In contrast to the samples stored at 65 % relative humidity, the samples stored at 95 % relative humidity have lower calcite and higher contents of portlandite and AFm phases.

No significant differences in the amount of calcite and water-containing mineral phases (portlandite, brucite, hydrotalcite) can be found after 28, 90 and 180 days. It can be concluded that a large part of the reactions has already taken place after 28 days.

The present study is believed to be beneficial for a thorough understanding of the phase formations in dolomitic lime based mortars at different curing conditions.
Global Air quality Forecast and Information Systems (GAFIS) - a new WMO - GAW initiative
Authors: Flemming Johannes , Tarasova Okasna , Ren Lu , Baklanov Alexander , Carmichael Greg
Published: March 2020

Air pollution is the single largest environmental risk factor to health globally; it contributes to climate change, is detrimental for ecosystems, damages property, impacts visibility and can threaten food and water security. A wide variety of Air Quality (AQ) systems operate at different spatial and temporal scales to provide information required to mitigate the impact of or to reduce air pollution. 

Recognising the importance to support the transition of scientific efforts into useful services, the Global Atmosphere Watch Programme (GAW) of the World Meteorological Organisation (WMO) has started an initiative on Global Air quality Forecast and Information Systems (GAFIS). GAFIS aims to become a network for the development of good practices for air quality forecasting and monitoring services using  diverse approaches. GAFIS will closely interact with existing GAW efforts on air pollution forecasting and dust strom prediction, and it intends to build strong links with the international health community. As a major first step, GAFIS will carry out and maintain a survey of AQ information systems and identify areas and regions with a lack of adequate AQ services. GAFIS aims to improve access to air quality observations and to encourage better quality control and meta-data provision.  GAFIS will initiate coordinated evaluation activities of air quality services using a harmonized evaluation protocol. Finally,  promoting operational applications of atmospheric composition feedbacks in Numerical Weather Prediction is a further objective of GAFIS.

In the presentation we will introduce GAFIS to the scientific community and invite collaboration within its framework. 
Nonlinear Fourier Analysis with Sine Wave, Stokes Wave and Rogue Wave Basis Functions: A Paradigm Change in the Understanding of Nonlinear Waves
Authors: Osborne Alfred
Published: March 2020

I give a new perspective for the description of nonlinear water wave trains using mathematical methods I refer to as nonlinear Fourier analysis (NLFA). I discuss how this approach holds for one-space and one time dimensions (1+1) and for two-space and one time dimensions (2+1) to all orders of approximation. I begin with the nonlinear Schroedinger (NLS) equation in 1+1 dimensions: Here the NLFA method is derived from the complete integrability of the equation by the periodic inverse scattering transform. I show how to compute the nonlinear Fourier series that exactly solve 1+1 NLS. I then show how to extend the order of 1+1 NLS to the Dysthe and the extended Dysthe equations. I also show how to include directional spreading in the formulation so that I can address the 2+1 NLS, the 2+1 Dysthe and the 2+1 Trulsen-Dysthe equations. This hierarchy of equations extends formally all the way to the Zakharov equations in the infinite order limit. Each order and extension from 1+1 to 2+1 dimensions is characterized by its own modulational dispersion relation that is required at each order of the NLFA formalism. NLFA is characterized by its own fundamental nonlinear Fourier series, which has particular nonlinear Fourier modes: sine waves, Stokes waves and breather trains. We are all familiar with sine waves (known for centuries) and Stokes waves (known since the Stokes paper in 1847). Breather trains have become known over the past three decades as a major source of rogue or freak waves in the ocean: Breather packets are known to pulse up and down during their evolution. At the moment of the maximum amplitude the largest wave in a breather packet is often referred to as a “rogue” or “freak” wave. Such extreme packets are known to be “coherent structures" so that pure linear dispersion does not occur as in a linear packet. Instead the breather packets have components that are phase locked with each other and hence remain coherent and are “long lived” just as vortices do in classical turbulence. Because the breathers live for a long time, the notion of risk based upon linear dispersion, as used in the oil and shipping industries, must be revised upwards. I discuss how to apply NLFA to (1) nonlinearly Fourier analyze time series, (2) to analyze wave fields from radar, lidar and synthetic aperture radar measurements, (3) how to treat NLFA to describe nonlinear, random wave trains using a kind of nonlinear random phase approximation and (4) how to compute the nonlinear power spectrum in terms of the parameters used to describe the rogue wave Fourier modes in a random wave train. Thus the emphasis here is to discuss a number of new tools for nonlinear Fourier analysis in a wide range of problems in the field of ocean surface waves.
The 2019 biomass burning season in South America: climate diagnostics, fire monitoring and air quality forecasting
Authors: Frassoni Ariane
Published: March 2020

The biomass burning season in South America is mainly concentrated between July and October, period characterized by dry conditions associated with the decay phase of the South American monsoon system. The dry season in South America starts at the end of March and beginning of April when the maximum convection starts its shift to northward South America. The climatological dryness condition over central South America during July to October increases the occurrence of vegetation fires. The number of active fires detected by the AQUA satellite from 1998 to November 2019 in South America indicate fires abruptly increase from July to August, reaching a peak in September. Fires convert vegetation used as fuel into a series of combustion products that can remain in burned places or can be transported to other places by the atmospheric circulation. The 2019 dry season in South America was characterized by an abnormal high occurrence of intense and persistent fire episodes that injected tons of aerosols into the atmosphere. The present study aims to perform a comparative assessment of the four last South American biomass burning seasons. To compare the 2019 biomass burning season with 2016, 2017 and 2018 season, in this paper it is presented the fire active data compiled by the National Institute for Space Research (INPE) for the periods of analysis, the climatological aspects associated with each season and finally the validation of the operational integrated meteorology/air quality forecasting system Brazilian developments on the Regional Atmospheric Modeling System of the Center for Weather Forecasting and Climate Studies (CPTEC/INPE), for the considered periods.
Thermal record of hyperextended rifted margins: the fossil record of the Pyrenees
Authors: Ducoux Maxime , Jolivet Laurent , Augier Romain , Masini Emmanuel , Calassou Sylvain
Published: March 2020

The thermal architecture of late rifting to breakup along the deep passive margins is still poorly known. This is mostly because of the limited access to industry drillhole data that, anyway, calibrate topographic highs and rarely the deepest rift domains (and even less the basement). However, unravelling this evolution is a fundamental requirement to define the ultimate exploration potential of these frontier domains. An alternative way to document this thermal evolution is to describe fossil analogues onshore. In this study, we use the fossil hyperextension record of the Pyrenean belt that was sampled by orogenic deformation into the North Pyrenean None and Nappe des Marbres alpine units. Previous studies have shown that the rift came into hyperextension and recorded locally mantle exhumation. These rift domains are associated with a HT-LP metamorphism event that was shown to vary spatially within the rift basin as well as into the basement. In order to restore the late rift thermal architecture of the Pyrenean hyperextended rift, we use a new compilation of Raman Spectroscopy measurements on Carbonaceous Material (RSCM) and Vitrinite Reflectance data. This method allows to record the palaeo-maximum temperatures in the sedimentary basins spatially as well as vertically and can be superposed to geological sections. This method was applied in almost 200 samples collected all along the belt at different stratigraphic level as well as into the Paleozoic basement. When the base of the rift basin is exposed, RSCM Tmax range between 450 and 620°C below a <5km thick sedimentary pile. Western Pyrenees was shown to be an exception as RSCM Tmax are less than 300°C on the outcropping superficial part of the rift basin. However; Vitrinite Reflectance data from wells that are calibrating the deep basin demonstrate that the same thermal intensity was actually reached. These results discard any lateral variation in thermal regime and is pointing out that it is a burial function into a (very)high late rift thermal gradient that largely exceed 100°c/km. Far from being restricted to the Pyrenean case, such a thermal evolution with the same amplitude gradient within the same exhumed mantle domains were documented in the Northern Red Sea example.
Climate services for large scale investments in infrastructure and climate resilience in the Danube Basin
Authors: Radonić Jelena , Turk Sekulić Maja , Ćulibrk Dubravko , Drews Martin , Dømgaard Mads L. , Wortmann Michel
Published: March 2020

The results presented in this contribution demonstrate the value of climate services for the planned construction of the new Wastewater Treatment Plant (WWTP) in Novi Sad, Serbia. In this case, climate services provided added value for the decision-making processes, in terms of enhanced effectiveness, optimized technological opportunities and minimized risks and by serving as the means of involving and better-informing end-users and stakeholders. The specific goal of the research was to improve climate change resilience of the WWTP and to facilitate better overall hygienic conditions in Novi Sad and to safeguard the potable water resources and the quality of the environment in the areas located downstream and under the influence of the Danube River.

In order to achieve it, preliminary activities were oriented on analyzing the current climate and hydrological conditions, engaging the relevant data providers, stakeholders and policy makers and evaluating what relevant local data would be useful for the study. The data collected was applied in the testing and for improving the Future Danube Multi-hazard, Multi-risk Model (FDM), a catastrophe model implemented in the OASIS Loss Modeling Framework (Oasis-LMF). The FDM is implemented for the entire Danube Basin. High-resolution components for pluvial flood risks were further implemented to the city of Novi Sad, Serbia, after successful testing in the Budapest region. Observations and model results were used in a climate change impact assessment with the purpose of identifying adaptation options, appraisal of adaptation options and integration of an adaptation action plan into the Feasibility Study of the WWTP construction. The results of the pluvial flood model for Novi Sad clearly suggested that it is important to consider pluvial flood risks and that protective measures have to be considered as part of the WWTP construction, both under current and future climate conditions. Moreover, novel estimates of drainage water intensities during heavy rains would advise the design of the simultaneously planned pumping station on the banks of the Danube. Combined, this clearly demonstrates the added value of the climate services and risk information delivered by the FDM also beyond the insurance sector, as well as its potential to support adaptation decision making with respect to infrastructural investments in Novi Sad.
Causes and implications of the unforeseen 2016 extreme yield loss in France’s breadbasket
Authors: Ben Ari Tamara
Published: March 2020

The 2016 wheat harvest in France suffered from an unforeseen and unprecedented production loss. At 5.4 tonnes ha-1, wheat yield was the lowest recorded since 1986 and 30% below the five-year average.  Crop yield forecasting can be considered as near-real-time impact modelling, but unfortunately, none of the forecasting systems in place anticipated the extent of the impact. The 2015/2016 growing season was characterized by compounding warm autumn temperatures and abnormally wet conditions in the following spring. High rainfall and high temperatures leading to fungal diseases, soil water lodging and anoxia, low radiation affecting grain filling, and leaching of nitrogen from the root-zone have all been suggested as important factors ultimately leading to the yield loss. The use of binomial logistic regressions accounting for autumn and spring temperatures and precipitation, suggests that the odds of an extreme yield loss in 2016 was times 35 higher than expected. The challenge now is to further identify the variety of biotic and abiotic processes interacting at different timescales. Collecting relevant insights on the field or from trial experiments, and confronting these with statistical and biophysical crop modelling will be key to achieve this. Improved impact relevant indicators will need to be integrated into operational crop yield forecasting systems in preparation for future compound events.
Airborne Hyperspectral Trace Gas Sensors as Testbeds for Geostationary Air Quality Mission Validation
Authors: Janz Scott , Kowalewski Matthew , Lamsal Lok , Judd Laura , Nowlan Caroline , Al-saadi Jassim
Published: March 2020

Next generation air quality sensors are currently planned to launch within the next couple of years. The Tropospheric Emissions: Monitory of Pollution (TEMPO-United States) and Geostationary Environment Monitoring Sensor (GEMS-South Korea) are two such missions that will probe the boundary layer/lower troposphere at unprecedented spatial and temporal scales. These missions are designed to provide constraints on chemical forecast models and specifically to answer the question: "What are the temporal and spatial variations of emissions of gases and aerosols important for air quality and climate?" In preparation for these missions a number of airborne air quality field missions have been performed to collect data at similar spatial and temporal scales, and during relevant seasonal air quality episodes including fires. This data is being used to improve the trace gas retrieval algorithms and explore the unique spatial scales and diurnal patterns that will be encountered when the geostationary experiments are operational. This overview will present details of two of the instruments used during these campaigns, the GeoCAPE Airborne Simulator (GCAS) and the Geostationary Trace Gas and Aerosol Sensor Optimization (GeoTASO) instruments. Maintained at the Goddard Space Flight Center's Radiometric Calibration and Development Facility (RCDF), these instruments are similar in design and sensitivty to what will be measured on-orbit by the TEMPO and GEMS sensors. Results of the retrieval of high spatial resolution nitrogen dioxide and formaldehyde will presented. Examples of vertical column retrievals will be presented under various source/weather conditions as well as the uncertainties that result from both instrument and radiative transfer assumptions.
Simulated experiment of recovering gravity field from the observations of satellite’s frequency signal
Authors: Xu Xinyu , Shen Ziyu , Shen Wenbin , Zhao Yongqi
Published: March 2020

Recovering the gravity field with the satellite’s frequency signal might be an alternative measuring mode in the future when the accuracy of the onboard clock was good enough. On the one hand, we analyze the performance of recovering gravity field model from the gravitational potentials with different accuracies on different satellite altitudes (from 200 km to 350 km) based on semi-analytical (SA) method. On the other hand, we analyze the performance based on the numerical analysis. First, the gravitational potentials along the satellite orbit are computed from the clock observations based on the method of satellite’s frequency signal with the accuracies of 10-16 and 10-18s. Then, based on the derived gravitational potentials, we recovered the gravity field models up to degree and order 200 (corresponding to 100 km spatial resolution). At last, the errors of recovered models are validated by comparing with the reference model.
Comparison of Dynamic Topography Bias in HIROMB and NEMO-Nordic Model by Utilizing Marine Geoid
Authors: Jahanmard Vahidreza , Delpeche-Ellmann Nicole , Ellmann Artu
Published: March 2020

Hydrodynamic models (HDM) provide a reasonable estimate of the sea conditions. Thus making them a vital tool for climate change, engineering, and marine ecosystems. One of the parameters often derived from HDM is the Sea Surface Height (SSH). There exists however a very important hidden characteristic with respect to SSH derived from HDM. For instance, the modelled sea level may have a bias relative to a geodetic reference system datum. In many cases, this bias can change both spatially and temporally. This study now examines this bias by comparison of HDM modelled SSH with tide gauges derived SSH that are geodetically referenced to a more stable vertical reference frame such as the marine geoid (equipotential surface of the earth i.e. is the shape of the ocean surface under the influence of the gravity and rotation of Earth alone).

In this study, the performance of two HDM is analysed for the period 2014‒2015: the Nemo-Nordic (utilised for the Baltic and the North Sea) and the HIROMB-BOOS (used for operational sea forecast in Estonia). In these models, the derived SSH is compared to the fourteen tide gauges (TG) located along the Estonian coastal zone of the Baltic Sea. The vertical reference frame for these tide gauges is fitted to that of a regional high-resolution geoid model, thus deriving the Dynamic Topography. The methodology consisted of: (i) determining the offshore points that are closest to the tide gauge location, (ii) filtering and averaging of the data sets to remove outliers and high-frequency fluctuations (iii) calculation of the SSH bias between TG and HDM (iv) calculation of the standard deviation and root mean square error (RMSE).

In general, results show that both models conform to a similar trend as tide gauge. The bias however between tide gauge and models varied randomly in magnitude (both spatially and temporally) between both models. The maximum bias for the HIROMB was calculated to be an overestimation of 57 cm and for the Nemo an underestimation of 64 cm. These results hint of possible improvement that can be made in HDM by utilizing a high resolution geoid model that can assist in accurate engineering and scientific studies.