bluuebunny/crossref_metadata_2025 huggingface dataset:
Cement render and mortar and their damages due to salt crystallization in the Holy Trinity Dominicans monastery in Cracow, Poland
Authors: Marszałek Mariola , Dudek Krzysztof , Gaweł Adam , Czerny Jerzy
Published: March 2020

The presented investigations are focused on a part of the 13th century Church of the Holy Trinity Dominicans monastery in Cracow, Poland, and include the wall façade of the 17th century Myszkowski chapel. The chapel was probably designed by Santi Gucci Fiorentino and built by his workshop. Southern façade of the chapel is made of Tertiary limestone blocks that make characteristic rusticated wall. Lower part of the façade is covered with cement and the basement is made of irregular fragments of Jurassic limestone and Cretaceous sandstone partly replaced and bound with cement mortar. The façade revealed clear signs of damage ranging from dark gray soiling of the surface, scaling to efflorescences. The last ones – mainly on the border of limestone blocks and the cement in the part of the basement.

Laboratory tests included mineralogical, chemical and petrophysical analyses. Optical microscopy, scanning electron microscopy (SEM-EDS), micro-Raman spectroscopy and X-ray diffractometry (XRD) were used for analysing materials and deterioration products of the cement render and mortar. The petrophysical properties of the materials have been performed using mercury intrusion porosimetry. The secondary minerals detected include mainly gypsum CaSO4·2H2O, thenardite Na2SO4,  aphthitalite (Na,K)3Na(SO4)2, darapskite, Na3(SO4)(NO3)·H2O, nitre KNO3, nitratine NaNO3, ettringite Ca6Al2(SO4)3(OH)12·26H2O and monosulphite Ca4Al2O6SO3·11H2O. Lower blocks of the façade covered with cement contain chiefly gypsum, ettringite and monosulphite, cement from the basement – gypsum and nitre; while efflorescences – thenardite, aphthitalite, darapskite, nitre and nitratine. The origin of the salts have been discussed and the differences in their type have been associated with composition of the materials and their physicochemical properties.

This work has been financially supported by the AGH University of Science and Technology, statutory grant no. 16.16.140.315.
The impact of snow products on detecting trends in sea ice thickness during the CryoSat-2 era
Authors: Sallila Heidi , Buzzard Samantha , Rinne Eero , Tsamados Michel
Published: March 2020

Retrieval of sea ice depth from satellite altimetry relies on knowledge of snow depth in the conversion of freeboard measurements to sea ice thickness. This remains the largest source of uncertainty in calculating sea ice thickness. In order to go beyond the use of a seasonal snow climatology, namely the one by Warren created from measurements collected during the drifting stations in 1937 and 1954–1991, we have developed as part of an ESA Arctic+ project several novel snow on sea ice pan-Arctic products, with the ultimate goal to resolve for the first time inter-annual and seasonal snow variability.

Our products are inter-compared and calibrated with each other to guarantee multi-decadal continuity, and also compared with other recently developed snow on sea ice modelling and satellite based products. Quality assessment and uncertainty estimates are provided at a gridded level and as a function of sea ice cover characteristics such as sea ice age, and sea ice type.

We investigate the impact of the spatially and temporally varying snow products on current satellite estimates of sea ice thickness and provide an update on the sea ice thickness uncertainties. We pay particular attention to potential biases of the seasonal ice growth and inter-annual trends.
Aerosol microphysical properties for selected case studies during the EMeRGe-EU and EMeRGe-Asia campaigns
Authors: Wolf Jennifer , Sauer Daniel , Eirenschmalz Lisa , Klausner Theresa , Schlager Hans
Published: March 2020

Aerosols can have a great impact on air quality and human health. In addition they can affect air transport by causing damage in aircraft engines.

To study the transport and transformation of anthropogenic pollutants from major population centers, two airborne measurement campaigns were conducted in the framework of the EMeRGe (Effect of Megacities on the transport and transformation of pollutants on the Regional to Global scales) Project using the German High Altitude-Long-Range (HALO) research aircraft. The aircraft was equipped with a wide range of instrumentation to measure atmospheric constituents. Here we report on results from the measurements characterizing aerosol microphysical properties. Measurements included particle number concentration and size distributions in a size range between 10 nm and ~3 µm as well as absorption properties. Aerosols were measured in the outflow of major population centers in Europe in summer 2017 (EMeRGe-EU) and along the Asian Pacific coast in spring 2018 (EMeRGe-Asia). In selected case studies we investigated detected aerosol layers, their likely source regions and transport paths. Case studies include the pollution along the west coast of Taiwan as well as the outflows of Manila (Philippines) and London (United Kingdom). Differences and similarities between Europe and Asia and the correlations with trace gases such as SO2, CO2 and CH4 are discussed.
Imaging the Walter Munk lake: Sedimentary dynamics and water resurgence derived from high-resolution seismic reflection survey in Lake Altaussee (Salzkammergut, Austrian Alps)
Authors: Alban Bouchard , Jouve Guillaume , Leloup Damien , Alain Philippe , Chapron Emmanuel
Published: March 2020

Alpine lake sediments in the critical zone have proven their efficiency to record regional climate variability and geohazard history at several time-scales. However, the understanding of lake responses to external environmental factors depends on a precise knowledge of internal lake functioning. High resolution imaging of lake sedimentary infill is crucial to unveil internal and external factors impacting sedimentary processes. In memory of Walter Munk and to his considerable contribution to underwater geophysics, we present 29 high-resolution seismic reflection lines data (8 cm resolution/10 meters penetration) from Lake Altaussee (Walter Munk hometown lake in Austrian Alps), recently acquired using iXblue Echoes 10 000 sub-bottom profiler. Interpretations are supported by multibeam echosounder bathymetry and hydrochemical data.

Lake Altaussee is situated at 713 m a.s.l. in Northern Calcareous Alps (Salzkammergut, Austria). Lake depression is 2.6 km long, 1 km width and mean water depth is 53 m. Three main echofacies are observed: High/low intensity reflectors following the lake bed topography, Structureless weak amplitude layer on top of the bedrock, Massive and discontinuous structures at the eastern part of the lake.

First type suggests a great potential to reconstruct Late Holocene environmental and climatic events. Second type is probably associated to a landslide. Third type is located on top of holes and water resurgence (also visible in the bathymetry) and is attributed to carbonate sedimentation due to supersaturation and oxygenated conditions at the karstic system output. This hypothesis is supported by lower temperature and salinity measured at the karstic system output. Using Delph Seismic software, we constructed 3D modeling of the lake sediments by generating isopaches of main reflectors and estimated spatial distribution of sediment volume. Our model help at deciphering different sedimentary dynamics along the lake infill history and to suggest the deposition of historical earthquake, flood, etc, on top of the bedrock.
Can we forecast the arrival of ICMEs for the whole Solar Systems?
Authors: Del Moro Dario , Napoletano Gianluca , Berrilli Francesco , Giovannelli Luca , Pietropaolo Ermanno , Foldes Raffaello
Published: March 2020

Solar wind transients, i.e. interplanetary coronal mass ejections (ICMEs) drive Space Weather throughout the heliosphere and the prediction of their impact on different solar system bodies is one of the primary goals of the Planetary Space Weather forecasting. We realized a procedure based on the Drag-Based Model (Vrsnak et al., 2013, Napoletano et al. 2018) which uses probability distributions for the input parameters, and allows the evaluation of the uncertainty on the forecast. This approach has been tested against a set of ICMEs whose transit times are known, obtaining extremely promising results.

We apply this model to propagate a sample of ICMEs from their sources on the solar surface into the heliosphere. We made use of the seminal works by Prise et al. (2015), Winslow et al. (2015) and Witasse et al. (2017) who tracked the ICMEs through their journeys using data from several spacecraft.

Considering the extremely short computation time needed by the model to propagate ICMEs, this approach is a promising candidate to forecast ICME arrival to planetary bodies and spacecraft in the whole heliosphere, with relevant application to space-mission short-term planning.
Assimilation of chlorophyll data into a stochastic ensemble simulation for the North Atlantic ocean
Authors: Santana-Falcón Yeray , Brasseur Pierre , Brankart Jean Michel , Garnier Florent
Published: March 2020

Satellite-derived surface chlorophyll data are daily assimilated into a three-dimensional 24 member ensemble configuration of an online-coupled NEMO-PISCES model for the North Atlantic ocean. A one-year multivariate assimilation experiment is performed to evaluate the impacts on analyses and forecast ensembles. Our results demonstrate that the integration of data improves surface analysis and forecast chlorophyll representation in a major part of the model domain, where the assimilated simulation outperforms the probabilistic skills of a non-assimilated analogous simulation. However, improvements are dependent on the reliability of the prior free ensemble. A regional diagnosis shows that surface chlorophyll is overestimated in the northern limit of the subtropical North Atlantic, where the prior ensemble spread does not cover the observation's variability. There, the system cannot deal with corrections that alter the equilibrium between the observed and unobserved state variables producing instabilities that propagate into the forecast. To alleviate these inconsistencies, a one-month sensitivity experiment in which the assimilation process is only applied to model fluctuations is performed. Results suggest the use of this methodology may decrease the effect of corrections on the correlations between state vectors. Overall, the experiments presented here evidence the need of refining the description of model's uncertainties according to the biogeochemical characteristics of each oceanic region.
Temperatures of Neoproterozoic Regional Carbonate Alteration in the Eastern Desert of Egypt
Authors: Boskabadi Arman , Kluge Tobias , Pitcairn Iain , Ali Rabea , Azer Mokhles , Maurice Ayman , Stern Robert , Bakhit Bottros , Shahien Mohamed , Zoheir Basem
Published: March 2020

Neoproterozoic ophiolites in the Eastern Desert (ED) of Egypt are pervasively carbonated and listvenitized. Two types of carbonation are recognized: 1) intergrown magnesite (and to lesser extent dolomite) with serpentine and talc that in cases form pure carbonate veins, and 2) cryptocrystalline magnesite veins filling the fractures crosscutting other ophiolitic host rocks. Few studies address the conditions of carbonate alteration of ultramafic rocks, especially the temperature of altering fluids. We employ clumped isotope thermometry on natural dolomite and magnesite from 17 variably carbonated ophiolitic rocks and veins in the ED. Five samples of antigorite-bearing serpentinite, talc-carbonate, and associated carbonate veins yield wide range temperatures of magnesite and dolomite between 213 to 426°C (285±73°C). These temperatures are comparable with previous fluid inclusion thermometry carried out on some of the vein samples (homogenization temperature between 225 to 383°C; Boskabadi et al. 2017). Ten samples of fully quartz-carbonate altered peridotites (i.e. listvenites) record even a wider range of clumped isotope carbonation temperatures between 90 and 452°C (227±112°C). In contrast, two samples of late-stage veins of cryptocrystalline magnesite record lower temperatures of 19 and 28°C. While the constraints on the pressure of carbonation are lacking, the wide range of temperatures for the carbonates in antigorite-bearing serpentinite, talc-carbonate, and listvenite lithologies suggest that carbonation probably occurred at variable depths, whereas the low temperature of cryptocrystalline magnesite veins points to conditions nearer the surface most likely associated with post-obduction processes. Therefore, different sources of carbon and CO2-bearing fluids should have been responsible for the formation of high- and low-temperature carbonates in the region.

 

  Boskabadi et al. 2017. International Geology Review 59, 391–419.
Evaluation of Air Pollutant Emission Inventories in East Asia
Authors: Kim Younha , Woo Jung-hun , Jang Youjung , Park Minwoo , Kim Bomi , Amann Markus , Klimont Zbigniew , Wagner Fabian , Schöpp Wolfgang , Sander Robert
Published: March 2020

Concentration of air pollutants such as tropospheric ozone and aerosols are mainly affected by meteorological variables and emissions. East Asia has large amount of anthropogenic and natural air pollutant emissions and has been putting lots of efforts to improve air quality. In order to seek effective ways to mitigate future air pollution, it is essential to understand the current emissions and their impacts on air quality. Emission inventory is one of the key datasets required to understand air quality and find ways to improve it. Amounts and spatial-temporal distributions of emissions are, however, not easy to estimate due to their complicate nature, therefore introduce significant uncertainties.

In this study, we had developed an updated version of our Asian emissions inventory, named NIER/KU-CREATE (Comprehensive Regional Emissions inventory for Atmospheric Transport Experiment) in support of climate-air quality study. We first inter-compare multiple bottom-up inventories to understand discrepancies among the dataset(sectoral, spatial). We then inter-compare those bottom-up emissions to the satellite-based top-down emission estimates to understand uncertainties of the databases. The bottom-up emission inventories used for this study are: CREATE, MEIC(Multiresolution Emission Inventory for China), REAS (Regional Emission inventory in ASia), and ECLIPSE(Evaluating the Climate and Air Quality Impacts of Short-Lived Pollutants). The satellite-derived top-down emission inventory had been acquired from the DECSO (Daily Emission derived Constrained by Satellite Observations) algorithm data from the GlobEmissions website.

The analysis showed that some discrepancies, in terms of emission amounts, sectoral shares and spatial distribution patterns, exist among the datasets. We analyzed further to find out which parameters could affect more on those discrepancies. Co-analysis of top-down and bottom-up emissions inventory help us to evaluate emissions amount and spatial distribution. These analysis are helpful for the development of more consistent and reliable inventories with the aim of reducing the uncertainties in air quality study. More results of evaluation of emissions will be presented on site.     

Acknowledgements : This work was supported by National Institute of Environment Research (NIER-2019-03-02-005), Korea Environment Industry & Technology Institute(KEITI) through Public Technology Program based on Environmental Policy Program, funded by Korea Ministry of Environment(MOE)(2019000160007). This research was supported by the National Strategic Project-Fine particle of the National Research Foundation of Korea(NRF) funded by the Ministry of Science and ICT(MSIT), the Ministry of Environment(ME), and the Ministry of Health and Welfare(MOHW) (NRF-2017M3D8A1092022).
Glacial-to-interglacial variations in the deep water at the Bermuda Rise inferred from a Nd isotope record covering the last million years
Authors: Jaume-Seguí Maria , Kim Joohee , Knudson Karla P. , Yehudai Maayan , Goldstein Steven L. , Bolge Louise , Ferretti Patrizia , Pena Leopoldo D.
Published: March 2020

The formation of North Atlantic Deep Water (NADW) in the North Atlantic is an important modulator of the climate system, as it drives the global termohaline circulation, responsible for the distribution of heat, salts and nutrients across the oceans. ODP Site 1063 (4584 m), on the deep Bermuda Rise, is located in the mixing zone between NADW and Antarctic Bottom Water (AABW) and appears to be a good location to study how ocean circulation and climate interconnect. Here we present a new record based on Nd isotope ratios that covers ~1 Ma at that Site. Our data shows Nd isotope ratios during parts of interglacials that are much lower than present day NADW. These results are coherent with recent published studies on the last interglacial–glacial cycle that show that the deep North Atlantic Nd isotope ratios are also lower than NADW during the early interglacial. However, Nd isotope values from the shallower DSDP Site 607 (3427 m), within the core of NADW, have remained similar to modern NADW during interglacials over the same time interval. Site 607 is thought to represent the deep North Atlantic, as shown by an Atlantic meriodional transect that displays Nd isotopes ratios for glacial and interglacial maxima over the last ~1 Ma. We suggest that Nd isotope ratios at Site 1063 do not fully represent the North Atlantic endmember of the AMOC during interglacials, but regional or local processes. However, glacial values at Site 1063 fitting those of Site 607 suggest that Nd isotope ratios represent, indeed, water mass mixing during glacial periods. The low Nd-isotope ratios in the deep Bermuda Rise during interglacials would be the result of particle-seawater exchange derived from the arrival of freshly ground, poorly weathered bedrock from the Canadian shield to the North Atlantic during major ice sheet retreats, such as deglaciations as well as stadial-to-interstadial transitions. Consequently, a deep, regionally constrained layer of seawater is tagged with this extreme Nd isotope signature that is not representative of the AMOC. We suggest that a benthic nepheloid layer, whose development is driven by a deep-recirculating gyre system regulated by the interaction between the northward flowing Gulf Stream and the southward flowing deep western boundary current, facilitates the periodical masking of the deep Atlantic Nd isotope signature at Site 1063. The intermittence of the masking allows for a speculation on how the deep-recirculating gyre system might have changed over the last ~1 Ma glacial-to-interglacial cycles.
Where now for forest trace gas research?
Authors: Gauci Vincent
Published: March 2020

Forests play an important role in the exchange of radiatively important trace gases with the atmosphere. The past decade has seen remarkable growth in interest in this research area with studies yielding ever-greater insight into both the importance of these exchanges and the fundamental processes of exchange in ecosystems that are vulnerable and highly responsive to agents of global change. I will provide an overview of previous studies that are now global in coverage, which have shown that in both temperate and tropical wetland and upland forests, tree stems constitute significant surfaces of exchange of both methane (CH4) and nitrous oxide (N2O). Considering studies spanning diverse forest biomes across the full latitudinal range of forest extent, leads to emergent questions that this new and developing pan-disciplinary coalition of researchers are increasingly well able to address. Given that forests are both sensitive and highly responsive to agents of global change at a range of scales, there is a need to further characterise the fundamental functioning of exchange processes in forests e.g. with respect to hydrology, climate and the biology of microbes and the trees and soils they inhabit. Such insight will help with planning the next generation of integrative studies, at scale, to enable the role of forests in trace gas cycling in a changing world to be characterised.
Thermochemical equilibrium modeling approach for carbon-rich feedstock gasification validated against laboratory and large-scale experiments
Authors: Otto Christopher , Kempka Thomas
Published: March 2020

In the present study, a pre-existing stoichiometric equilibrium model based on direct minimization of Gibbs free energy has been further developed and applied to estimate the equilibrium composition of synthesis gases produced by the gasification of carbon-rich feedstock (e.g., coal, municipal waste or biomass) in a fixed-bed reactor [1]. Our modeling approach is validated against thermodynamic models, laboratory gasification and demonstration-scale experiments reported in the literature. The simulated synthesis gas compositions have been found to be in good agreement under a wide range of different operating conditions. Consequently, the presented modeling approach enables an efficient quantification of synthesis gas compositions derived from feedstock gasification, considering varying feedstock and oxidizer compositions as well as pressures and temperatures. Furthermore, the developed model can be easily integrated with numerical flow and transport simulators to simulate reactive transport of a multi-componentgas phase.

[1] Otto and Kempka, Synthesis gas composition prediction for underground coal gasification using a thermochemical equilibrium modeling approach, Energies (in review)
Jupiter’s gravity field updates from Juno
Authors: Durante Daniele , Parisi Marzia , Serra Daniele , Zannoni Marco , Notaro Virginia , Racioppa Paolo , Buccino Dustin R. , Lari Giacomo , Gomez Casajus Luis , Iess Luciano , Folkner William M. , Tommei Giacomo , Tortora Paolo , Bolton Scott
Published: March 2020

The Juno spacecraft arrived at Jupiter’s system on July 4th, 2016 and reached the mid-point of its nominal mission in December 2018, after completing 17 perijove passes. Juno is currently orbiting Jupiter in a highly eccentric orbit, with a perijove altitude of about 4000 km that provides great sensitivity to the gravitational field of the planet. The radioscience instrumentation on board Juno enables very accurate radial velocity (Doppler) measurements, with noise as low as 10 micron/s at an integration time of 60 s. The gravity field of the planet is recovered though detailed reconstruction of Juno’s motion and observation model, performed with JPL’s and University of Pisa’s latest precise orbit determination codes, MONTE and ORBIT14 respectively.

We provide an update on Jupiter’s gravity field, its tidal response and spin axis motion over the first half of Juno’s mission. Although the Doppler data collected during the first two gravity-dedicated perijove passes have been reduced to the noise level by assuming a purely axially symmetric field for the gas giant, the current dataset, which includes ten passes, hints to a non-static and/or non-axially symmetric field, possibly related to several different mechanisms, such as normal modes, localized atmospheric or deeply-rooted dynamics.
Complex seismic activity and local stress perturbation of the Pyeongnam basin, northern Korean Peninsula
Authors: Kang Tae-Seob , Lee Heekyoung
Published: March 2020

The western region of the Pyeongnam Basin has relatively higher e​arthquake activity than the rest of the Korean Peninsula. We analyzed 48 earthquakes in the area, with a magnitude (ML) of 2.0 or more, from January 2009 to June 2019. The hypocentral parameters were re-determined using an iterative algorithm that repeats the calculation until the residual error between the observed and calculated arrival time of a seismic phase at each station is minimized. Using the hypocenters and the optimal 1-D velocity model derived from this process, the focal mechanisms were determined using the first-motion polarities of body waves. Many earthquakes are associated with left-lateral strike-slip faults, with a strike in the NW-SE direction and a normal faulting component. A stress inversion was performed using data of the pressure and tensional axes from the focal mechanisms. The maximum principal stress in the study area acts in the NW-SE direction with high angles of plunge and differs from the maximum horizontal principal stress in the rest of the Korean Peninsula. This stress perturbation is caused by the detachment of a small local stress from the regional stress field due to the presence of weak faults with low shear strength that develop in the sedimentation environment of the Pyeongnam Basin.
The Origin of Saturn’s Rings Revisited
Authors: Teodoro Luis , Estrada Paul , Kegerreis Jacob , Cuzzi Jeff , Eke Vincent , Cuk Matija
Published: March 2020

A set of key observations over the Cassini spacecraft's tenure has constrained Saturn's rings' age to be less than a few 100 Myr effectively ruling out currently accepted ring origin scenarios, all of which require that the rings are ancient or primordial. We propose a new scenario motivated from evidence of a comparably recent dynamical instability ~100 Myr ago which would have led to collisions between Saturn's pre-existing mid-size icy moons, opening the door to possible ring formation during that epoch. Successfully testing this scenario requires better  understanding of collisional outcomes. Toward that end, we introduce a new suite of simulations modeling impacts between Saturn's icy moons using the next generation smoothed hydrodynamical and gravity code SWIFT. The unprecedented spatial resolution achieved in these simulations (108.5 particles within the simulation box) allows us to depict the myriad of gravitationally bound objects formed during icy moon collisions which may afterwards evolve both thermally and dynamically to re-accrete or collide with other bodies. Our unprecedented high resolution further allows us to determine a size distribution of fragments which can be used to inform crater impact distributions on newly accreted or remaining moons.

 
Dynamic Energy-Water-Land hotspots at variable spatial scales across the United States
Authors: Khan Zarrar , Wild Thomas , Vernon Chris , Hejazi Mohamad , Iyer Gokul , Graham Neal
Published: March 2020

Energy, water, and land (EWL) resource planning at regional (e.g. large river basins, states and provinces, balancing authorities) and sub-regional (e.g. sub-basins, counties, Agro-Ecological Zones (AEZ)) scales has commonly been conducted in relative isolation by institutions focused on individual sectors, such as water supply or electricity. The effectiveness of this traditional approach is increasingly being strained by rapid integration among sectors as well as by a range of regional and global forces, such as climate, technological and socioeconomic change. In this study we explore regional and sub-regional implications of these changes across the United States for a suite of scenarios representing a range of socio-economic and climate pathways. We couple a global integrated assessment model with a suite of sectoral downscaling tools to analyze the evolution of EWL hotspots at variable spatial scales. The ability to flexibly telescope into regions to identify the evolution of dynamic EWL hotspots allows planners to capitalize on synergistic opportunities as well as avoid potential conflicts across sectors at stakeholder specific jurisdictional boundaries as well as in the context of the larger region.
Microbes meet Structure - Soil Ecology in Microengineered Soil Chips
Authors: Hammer Edith , Mafla Endara Micaela Paola , Arellano Carlos G. C. , Aleklett Kristin , Pucetaite Milda , Ohlsson Pelle
Published: March 2020

Many soil processes are governed by microbes, and biological and physical processes influence each other. We recently developed microfluidic model systems that simulate the spatial microstructure of soil microbial habitats in a transparent material, which we call Soil Chips. They allow us to study the impact of soil physical microstructures on microbes, and vice versa, the influence of microbes on soil physical properties: such as Microbial behavior and interactions in response to a spatially refined habitat, or wettability and water retention, soil aggregate formation and changes in the pore space.

We inoculated our chips with fluorescent lab cultures or natural whole soil inocula. Through the chips we observed via microscopy processes in real-time and at the scale of the microbial cells.

We could study fungi, bacteria, protists and nematodes as well as the distribution of soil minerals and soil solution in the chips. We subjected the adjacent soil to drying-rewetting processes, which was visible in water movements inside the chip. We studied the development of preferential water flow paths, and water retention in smaller pores and as a consequence of microbial exudates. Also the microbes themselves influenced the formation of microhabitats, where fungal hyphae both blocked connections and pushed through existing borders, and single-celled protozoa opened passages through existing aggregates. We found that the presence of fungal hyphae in a pore space system increased both the presence of bacteria and the likelihood of water in the pores, and thus allowing us to study fungal highways in a more realistic soil setting.

The chips act like a window into the soil, through which we can eaves-drop on a world that otherwise is largely hidden to us: Jostling protists, tsunami-like drying-rewetting events, and fungi with character. Beyond the scientific potential, the chips can also bring soils closer to people and hopefully increase engagement in soil health conservation.
Fluid network framing the hydrothermal system beneath Mt. Erciyes, Central Turkey
Authors: Karaş Mustafa , Üner Serkan , Tank Sabri Bülent
Published: March 2020

Fluid contribution in a tectonic process is a crucial parameter for characterization of its products. In the geophysical point of view, illustrating the electrical resistivity structure of any tectonic system can be used to determine effects of fluid contribution. Magnetotellurics is globally used to decipher characteristics of fault zones, volcanoes and hydrothermal systems which are related to driving tectonic regime in collision and transition zones. Mt. Erciyes, which is the largest composite volcano of the Central Anatolian Volcanic Province in Turkey, developed in two particular stages during the Quaternary. Igneous activities in Koçdağ and New Erciyes stages created a plausible environment to observe dominant calc-alkaline products while alkaline and tholeiitic components are also present in the region. Geochemical evidences offer that fractional crystallization combined with low degree crustal assimilation were experienced during the formation of the volcano in addition to potential magma mixing processes occurred in the magma chambers. As part of NSF-funded Continental Dynamics/Central Anatolian Tectonics Project (CD/CAT), this study aims to investigate electrical resistivity structure beneath Mt. Erciyes by means of three-dimensional modeling of the wide-band magnetotelluric data collected at 48 sounding locations. Current model depicts a high conductivity anomaly beneath Mt. Erciyes, which corresponds to its hydrothermal system and related clay cap. Within Erciyes pull-apart basin, local branches of Ecemiş Fault Zone that possibly reinforced the convenient setting for the upwelling of volcanic materials, bound the interconnected highly conductive zones in shallow depths. Under these circumstances, a complex resistivity distribution arises as a consequence of various electrical transfer mechanisms contemplated for the study region.
A new look at polarity information in D" reflections
Authors: Thomas Christine , Cobden Laura , Jonkers Art
Published: March 2020

Polarities of seismic reflection of P and S-waves at the discontinuity at the top of  D" are usually assumed to indicate the sign of the velocity contrast across the D" reflector. For reflections in paleo-subduction regions the S-wave reflections off D" (SdS) are the same as ScS and S, indicating a positive velocity contrast at the reflector. In recent years, an opposite polarity of PdP waves (P-reflection at the D" discontinuity) has been observed in some regions, partly dependent on travel direction, partly dependent on distance. This would indicate a velocity reduction in P-waves where a velocity increase is detected in S-waves. This phenomenon can be explained with the presence of post-perovskite below the top of D", but azimuthal dependence of PdP polarities can be better explained with anisotropy. Here we re-analyse PdP and SdS wave polarities and, when modelling the polarities and amplitudes using Zoeppritz equations, we find that a ratio of dVs/dVp= R of larger than 3 reverses polarities of P-waves in the absence of anisotropy, i.e. we find a polarity of PdP that would point to a velocity decrease while modelling a velocity increase. The S-polarity stays the same as S and ScS and does not change even with large R. Values of R up to 4.1 have been reported recently, so these cases do exist in the lower mantle. Using a set of 1 million models with varying minerals and processes across the boundary, we carry out a statistical analysis (Linear Discriminant Analysis, LDA) and find that there is a marked difference in mantle mineralogy to explain R values larger and smaller than 3, respectively. The regime of cases with R-value larger than 3 is mostly due to an increase in MgO and post-perovskite across the discontinuity. In regions where high R is observed, alternate explanations of lowermost mantle composition versus anisotropy can then be tested by measuring polarities in different azimuths.
Using N2O to detect if a tipping point has been crossed in tropical soils after droughts
Authors: Kilian Salas Simone , Díaz García Elisa , Andrino Alberto , Meurer Katharina H. E. , Boy Diana , Horn Marcus , Boy Jens , Jungkunst Hermann
Published: March 2020

The western Amazon is particularly sensitive to drought since precipitation is common even during "dry season". The combination of increasing land use pressure and droughts due to climate change makes the scenario of this ecosystem likely to cross or having crossed tipping points. We argue that nitrous oxide (N2O) emissions can be used to identify the crossing of tipping points in soils, particularly those related to N-cycling. This hypothesis is being tested within the BMBF funded Project PRODIGY, which will show that under stress microbial functional diversity in soils are a safety-net for ecosystems. The survey area (MAP) spreads across three countries (Peru, Brazil and Bolivia). Lab and field experiments are used to test our hypothesis based on the observations that N2O emission under tropical pasture shift after 10 years in use. Pre-measurement modeling is used to optimize measurement designs. Replicated above-ground biodiversity levels (n=4) will be sampled in each country. The soil will also be used for lab drought manipulation experiments to unravel underlying mechanisms. Measured values have shown to be lower than expected and simulated rates. Maybe because tipping points at different spacial and temporal scales are crossed faster than in temperate regions and biogeochemistry is less understood? Results from this investigation will allow the improvement of N2O models for tropical soils.
Airborne in situ tracer observations in the 2019 Springtime Antarctic UTLS during the HALO SouthTRAC campaign
Authors: Volk C. Michael , Lauther Valentin , Rau Andrea , Hader Fridolin , Cvetkova Svetlana
Published: March 2020

During the recent SouthTRAC (Transport and composition of the Southern Hemisphere UTLS) campaign the German High Altitude and LOng range research aircraft (HALO) intensively probed the bottom of the Antarctic vortex and the adjacent mid to high latitude upper troposphere / lower stratosphere (UTLS) throughout late winter and spring 2019.  A main goal of this mission was to study dynamics, transport and composition of this region, and particularly to assess the impact of the Antarctic vortex on the southern hemisphere UTLS.  The Antarctic winter 2019 was extraordinary with respect to dynamics, with a sudden stratospheric warming (only the second one ever observed) leading to a less stable and unusually warm polar vortex. The campaign consisted of two phases based in Rio Grande, Argentina (54°S) and comprised a total of 27 science flights including transfer flights to/from Argentina and 13 local flights from Rio Grande in September/early October and in November 2019.  A number of these flights penetrated into the lower Antarctic vortex, others crossed streamers or thin filaments shed from the vortex by frequent Rossby wave breaking events.

We present observations obtained on board of HALO by the University of Wuppertal's High Altitude Gas Analyzer –V (HAGAR-V), a 5-channel in-situ tracer instrument recently developed for HALO to study the chemical composition, dynamics, and transport in the UTLS.  HAGAR-V combines i) a fast CO2 measurement by NDIR analyzer (every 3 s), ii) a 2-channel GC/ECD-system measuring the long-lived tracers CFC-12, SF6 (every 40 s), CFC-11, CFC-113 and Halon-1211 (every 80s), and iii) a 2-channel GC/MS system measuring a large suite of further long-lived (e.g. HFCs) and short-lived halogenated tracers, including further chlorine source gases (e.g. CCl4, CH2Cl2, CHCl3, C2Cl4, HCFCs) every 2-4 minutes.  We will discuss the unusually active dynamics and associated tracer transport in the vicinity of the 2019 Antarctic vortex reflected by these measurements, and show the temporal development of vertical distributions and tracer correlations throughout the spring.  We will also compare the tracer distributions during SouthTRAC with those observed from the M55 Geophysica aircraft during the 1999 Antarctic campaign APE-GAIA.
Reconstructing ocean temperatures using coccolith clumped isotopes
Authors: Mejia Luz Maria , Fernandez Alvaro , Zhang Hongrui , Guitian Jose , Bernasconi Stefano , Stoll Heather
Published: March 2020

     Reliable temperature reconstructions of the ocean are often difficult to obtain due to the limitations of widely used proxies. The application of clumped isotope thermometry to coccolith calcite, which is geographical and chronological ubiquitously distributed, and whose production is limited to the photic zone, may provide ocean’s temperature information when and where other proxies have been shown inaccurate or not applicable.

     To evaluate the potential of coccolith clumped isotopes in paleoceanography we compare the temperatures derived from the fine fraction (<11µm), a pure mixed coccolith fraction (2-10 µm), and to a fraction of carbonate fragments from unidentified sources (<2 µm), with coeval alkenone sea surface temperatures (SST) from ODP Site 982 in the North Atlantic covering the last 16 Ma. The similarity in magnitudes and trends from the <11 and 2-10 µm size fractions, and trace element analysis of the <2 µm size fraction, suggest that for this site and time interval, exclusion of small unrecognizable fragments is not necessary to obtain reliable temperatures. The warmer values of alkenone SSTs compared to coccolith clumped isotope-derived temperatures cannot be explained by diagenetic processes, but may be related to temperature overestimations by alkenone calibrations, which assume a warm season and/or shallow production of coccolithophores in the study area.           

     Vital effects in coccolith clumped isotopes potentially associated to carbon limitation may also help to explain the differences in cooling magnitudes compared to the alkenone record. To further investigate vital effects in clumped isotopes, we compare calcification temperatures of three pure coccolith size fractions (3-5, 5-8, and 8-10 µm), and relate them to vital effects observed in their δ13C and δ 18O. The analysis of the fine fraction of Holocene sediments (<10 or <8 µm) showing a range of temperature and CO2 concentrations also provide information on the potential effects of carbon availability in coccolith clumped isotopes, and suggests calcification of coccolithophores may occur in deeper habitats than those considered by alkenone calibrations. Our study shows clumped isotope thermometry applied to coccolith calcite as a promising alternative proxy for calcification temperature of coccolithophores.
Analyzing the effect of earthquake correction on GRACE-derived drought indicators
Authors: Rietbroek Roelof , Gerdener Helena , Engels Olga , Kusche Jürgen
Published: March 2020

For many years the satellite gravity mission Gravity Recovery And Climate Experiment (GRACE) provided important insights into a large number of hydrological processes on Earth. However, to derive observations that can be used for hydrological applications many different postprocessing steps, e.g. filtering, replacement of low-degree coefficients, correction for glacial isostatic adjustment, need to be applied. Therefore, the official analysis centers meanwhile also provide postprocessed total water storage anomalies on a grid. Unfortunately, the effect of large earthquakes is usually not reduced. The resulting biases and artefact trends then bias hydrological analysis such as the detection of droughts and their severity.

 

For the first time, we analyze the effect of large earthquake correction on GRACE-derived Drought Severity Index (DSI) over Peninsular Malaysia in the period 2003 to 2016. For this, we perform a time series analysis based on GRACE-derived total water storage anomalies, while estimating, among others, a co-seismic and post-seismic signal using a nonlinear Bayes estimator (Einarsson et al. 2010). Our results show that the earthquake correction has a significant impact on the detected drought severity, suggesting that the earthquake correction may become a standard tool in time series analysis of GRACE and GRACE-Follow-On level-3 data.
Dynamic source inversion of the 2014 Mw6 South Napa, California, earthquake
Authors: Premus Jan , Gallovic Frantisek
Published: March 2020

Dynamic rupture modeling coupled with strong motion data fitting (dynamic source inversion) offers an insight into the rupture physics, constraining and enriching information gained from standard kinematic slip inversions. We utilize the Bayesian Monte Carlo dynamic source inversion method introduced recently by Gallovič et al. (2019), which, in addition to finding a best-fitting model, allows assessing uncertainties of the inferred parameters by sampling the posterior probability density function. The Monte Carlo approach requires running a large number (millions) of dynamic simulations due to the nonlinearity of the inverse problem. It is achieved by using GPU accelerated dynamic rupture simulation code FD3D_TSN (Premus et al., submitted) as a forward solver. We apply the inversion to the 2014 Mw6 South Napa, California, earthquake, employing strong motion data (up to 0.5 Hz) from the 10 closest stations. As an output, we obtain samples of the spatial distributions of dynamic parameters (prestress and parameters of the slip-weakening friction law). Regarding the rupture geometry, we consider two, presently ambiguous, fault planes (Pollitz et al., 2019), showing considerable differences in fitting seismograms in very close vicinity of the fault. We investigate properties of the rupture, especially in the region close to the free surface, and the viability of the model samples to explain the observed data in a broader frequency range (up to 5Hz).
Benchmark rock fall hazard assessment and safety concept for touristically developed alpine gorges (Höllentalklamm, Bavarian Alps).
Authors: Jacobs Benjamin , Grabmaier Andreas , Krautblatter Michael
Published: March 2020

The Höllentalklamm (Höllental Gorge) in Grainau is part of the main mountaineering route to the Zugspitze and with up to 2000 daily visitors a major tourist attraction in the Bavarian Alps. Following several recent rock fall events (up to 300 m³) the TU Munich collaborates with the local Alpine Club (DAV-GAP) to detect, assess and monitor rock fall hazards and to develop a benchmark safety concept for the Höllentalklamm. We combine multi-temporal terrestrial laser scanning, field mapping and the use of wireless sensor networks and evaluate the applicability of these methods for deeply incised alpine gorges.

In this study, we investigate a deeply incised and tectonically shaped alpine gorge in a well-researched mountain range (Wetterstein). In visibly accessible areas, multi-temporal terrestrial laser scanning is applied to (a) detect active rock fall areas, (b) identify hazardous objects pre-failure and (c) monitor potentially unstable parts of the rock face. Additionally, larger objects, such as a 600 m³ rock tower located directly above the track, are equipped with a redundant crackmeter system implemented in a wireless sensor network. Together with the DAV Garmisch-Partenkirchen, we are working on the development of safety procedures and the implementation of an automated early warning system. The first results show that terrestrial laser scanning is well-suited to detect post- and pre-failure rock falls above the level of detection, however, monitoring of small deformations remains a challenge. The crackmeters provide sub-millimetre deformation data of the rock tower and show generally stable conditions but a significant sensitivity towards external triggers such snow blasting in spring. Aside from that, direct rock fall hits hinder the sensor maintainace.

Here we show a benchmark rock fall hazard assessment and safety concept for Alpine gorges with high safety demands providing four years of data. This work helps to evaluate the applicability of well-established monitoring techniques in confined and inaccessible terrain (deeply incised gorges).