bluuebunny/crossref_metadata_2025 huggingface dataset:
Pesquisadores da comunidade arquivística brasileira nos espaços de interlocução internacional franceses
Authors: Marques Angelica Alves da Cunha , Praciano Bruno Justino Garcia
Published: March 2020

Objetivo: Recorte de uma pesquisa sobre a internacionalização da Arquivologia e institucionalização da disciplina no Brasil a partir dos seus diálogos com a França, este artigo objetiva apresentar a participação de pesquisadores da comunidade arquivística brasileira em cursos, publicações e eventos científicos franceses. Método: Em uma abordagem quali-quantitativa, caracteriza-se como uma pesquisa exploratória e descritiva, desenvolvida a partir da análise documental de 499 currículos de autores, orientadores e coorientadores de 470 teses, dissertações e TCCs sobre arquivos e Arquivologia, cadastrados na Plataforma Lattes do CNPq. Resultado: Os resultados deste mapeamento são comparados aos de um levantamento de 2011 e representam um aumento de mais de três vezes no número de pesquisas; de mais de duas vezes no número de pesquisadores, no de mestrados e doutorados cursados na França e no de artigos publicados em periódicos franceses; e de mais de seis vezes no número de capítulos de livros publicados naquele País. Conclusões: Ainda que as informações mapeadas nos currículos dos pesquisadores brasileiros estejam aquém da realidade, constatou-se um aumento significativo no número de suas participações em cursos, publicações e eventos científicos franceses. Contudo, essas participações ainda são escassas, tanto quantitativa quanto qualitativamente, diante das tradicionais relações entre o Brasil e a França.
Notas a respeito de homens negros nas narrativas de Rodolfo Xavier para o jornal A Alvorada (Pelotas, Pós-abolição)
Authors: Balladares Ângela Pereira Oliveira
Published: March 2020

O objetivo do artigo é dialogar sobre os homens negros que foram escolhidos pelo articulista Rodolfo Xavier (1876-1964), em seus escritos para o impresso negro racial A Alvorada, de Pelotas. Atento também para as escolhas, as intenções e os sentidos da preferência de Rodolfo Xavier por sujeitos específicos em suas produções textuais. Sendo assim, busco contribuir para a valorização das ideias e pensamento de homens negros gerados a partir de espaços alternativos, como a imprensa negra. Para a efetivação desta pesquisa, os estudos desenvolvidos por Beatriz Loner a respeito da classe trabalhadora de Pelotas e os estudos sobre o pós-abolição são referências fundamentais.
Improving Temporomandibular Range of Motion in People With Duchenne Muscular Dystrophy and Spinal Muscular Atrophy
Authors: Lloyd Morris Evan Harry , Estilow Timothy , Glanzman Allan M. , Cusack Stacy Victoria , Yum Sabrina W.
Published: March 2020

Importance: People with Duchenne muscular dystrophy (DMD) and spinal muscular atrophy (SMA) develop impaired oral function because of reduced temporomandibular joint range of motion (ROM), which affects feeding and oral hygiene activities of daily living (ADLs).

Objective: To assess whether the TheraBite®, an intraoral stretching device, improves ROM.

Design: Case series, with intervention duration varying from 7 to 30 mo. Treatment frequency varied from weekly to consultative (several times per year).

Setting: Varied depending on the ease of transportation for the participant and caregivers. Two participants were treated in an outpatient medical clinic. The other was provided consultative care during multidisciplinary medical clinics and completed a home program.

Participants: Two adults with DMD and one with SMA.

Intervention: Stretching protocol using the TheraBite.

Outcomes and Measures: Temporomandibular active ROM (AROM) was determined using a disposable TheraBite oral goniometer. Passive ROM (PROM) was determined using the adhesive scale on the TheraBite. Measures were taken at baseline, each intervention or consultation, and the end of care. ADL participation and caregiver burden were measured at the end of intervention.

Results: For participants with DMD, AROM remained unchanged, but PROM increased by 40%–65%. The participant with SMA demonstrated 33% and 47% improvements in AROM and PROM, respectively. Participants or caregivers reported improved feeding function, improved oral hygiene, or reduced fatigue.

Conclusion: TheraBite may improve temporomandibular PROM in people with DMD and temporomandibular AROM and PROM in people with SMA. It may also improve ADL function and consequently reduce caregiver burden. Further investigation is warranted.

What This Article Adds: Temporomandibular contracture in people with DMD and SMA contributes to reduced lifespan and loss of function. Use of the TheraBite with this population may preserve temporomandibular ROM and improve feeding, hygiene, and quality-of-life outcomes.
Refining chronologies by dating pollen concentrates – new approach of separating pollen using flow cytometry
Authors: Steinhoff Christoph , Pickarski Nadine , Litt Thomas
Published: March 2020

Radiocarbon dating of terrestrial plant-remains is a traditional method for precise age estimations of lake sediments. The absence of sufficient large plant macrofossils required for AMS dating in continental records, especially large lakes, demands for a satisfactory alternative, such as carbon-containing microfossils. Due to their ubiquitous presence in sedimentary archives pollen grains may be considered for dating. Nevertheless, the isolation and enrichment of pollen without a significant carbon contamination is still challenging. Even though commonly applied separation techniques can be used to remove the predominant portions of foreign particles, the undesirable transfer of these particles into the pollen concentrate cannot be excluded, yet. However, flow cytometry, as a highly promising alternative, offers the possibility to sort huge quantities of particles in a short period of time and to generate pure pollen concentrates from heterogeneous samples suitable for AMS radiocarbon dating.

In this study we present the approach to sort limnic sediment samples using flow cytometry. We are able to unequivocally identify pollen populations in the heterogeneous composition of the sediments and isolate them. The sediments analyzed were taken from the continental record of Lake Van (Eastern Anatolia). Annually laminated layers from the Holocene section of the sediment cores allow a precise temporal classification and validation of generated radiocarbon ages derived from fossil pollen. Although it is now possible to produce pollen concentrates without the contamination of foreign particles, the isolation of a sufficient quantity of pollen grains to generate reliable radiocarbon ages is still difficult. An increase pollen yield is required. Due to the limitation of the initial material, it is therefore especially necessary to improve the efficiency during the cytometric analysis.

Our results show the importance to steadily optimize the processing steps during chemical pretreatment, cytometric analysis as well as the radiocarbon dating itself. This facilitates the handling of the ultra-small samples and ensures precise age estimations of the pollen concentrates. Furthermore improving the laboratory routine for the enrichment of pollen will allow the analysis of vast amounts of samples in a short period of time. In consequence, dating pollen concentrates generated by flow cytometry can be used as a robust contribution and independent time control for existing chronologies in continental climate records.
Complex spatiotemporal patterns of intracontinental earthquakes: a different game
Authors: Liu Mian , Chen Yuxuan , Stein Seth , Luo Gang , Wang Hui
Published: March 2020

Intracontinental earthquakes show complex spatiotemporal patterns. In North China, no large (M>7) earthquakes ruptured the same fault segments in the past 2000 years; instead they roamed among widespread fault systems. In Australia, morphogenic evidence indicates clusters of earthquakes separated by tens of thousands of years of dormancy. In central and eastern United States, paleoseismic studies suggest that large Holocene earthquakes occurred in places that are seismically inactive today. Such seismicity does not fit existing earthquake models that assume steady tectonic loading and cyclic stress release on fault planes. Intracontinental fault systems are widespread and collectively accommodate slow tectonic loading. A major fault rupture both transfers stress to the neighboring faults and perturbs loading conditions on distant faults. Thus, the loading rate on each individual fault can be variable. Slow tectonic loading means that local stress variations from fault interaction or nontectonic processes, or changes of fault strength, could trigger an earthquake. Furthermore, large intracontinental earthquakes usually rupture multiple fault segments or faults, which vary for each event. For these earthquakes, commonly used concepts such as recurrence intervals and characteristic earthquakes, all based on earthquake models assuming cyclic elastic rebound, are inadequate or inapplicable. On the other hand, the general patterns of intracontinental earthquakes can be described by the theory of complex dynamic systems, in which all faults interact with each other. The rupture of individual fault or fault segment cannot be predetermined, but the system behavior can be studied based on the records of previous events. We found that large intracontinental earthquakes, either on a fault system or in a region, are usually clustered and separated by long but variable periods of quiescence. The lengths of the quiescence periods inversely correlate with tectonic loading rates, and the characteristics of earthquake clusters depend on fault geometry and crustal rheology, through fault interaction and viscoelastic relaxation. Spatially, large intracontinental earthquakes are not limited to faults that are active recently, although weak regions tend to have more earthquakes. Intracontinental earthquakes require a different approach, one that focuses on stress interactions between faults in a complex dynamic system rather than stress accumulation and release on individual faults.
Effect of Improved Bedrock Geometry on Antarctic Vulnerability to Regional Ice Shelf Collapse
Authors: Martin Daniel , Cornford Stephen , Ng Esmond
Published: March 2020

The Antarctic Ice Sheet (AIS) is vulnerable to the thinning or even the collapse of its floating ice shelves, which tend to buttress ice streams. Any reduction in buttressing results in acceleration and thinning upstream and potentially the onset of Marine Ice Sheet Instability. Recent work demonstrates that West Antarctica is vulnerable to sustained disintegration in any of its major marine outlets, resulting in 2-3 m sea level rise over 1000 years. At the same time regions in East Antarctica are vulnerable only to the loss of local ice shelves. However, most of this work has used the Bedmap2 dataset as a starting point. Since the release of Bedmap2 in 2012, there has been a sustained campaign of observations, along with improved interpolation techniques based on mass conservation. The resulting datasets, including the recently released BedMachine dataset, incorporate much-improved bedrock and thickness data compared to what was available in Bedmap2. 

We reproduce our previous examination of the millennial-scale vulnerability of the AIS to the loss of its shelves to examine the effect of this improvement on projected Antarctic vulnerability, paying special attention to regions like the Aurora Basin which were under-constrained in Bedmap2.
How Available is Phosphorus from Sewage Sludge Incinerator Ash?
Authors: Ma Persephone , Rosen Carl
Published: March 2020

The Twin Cities (Minneapolis and Saint Paul) of Minnesota (MN) in the United States incinerate sewage sludge for energy.  Every day at the Metropolitan Wastewater Treatment Plant, 650 million liters of wastewater are converted to an average of 5 MW of power and 32 MT of ash (SSA).  This ash is currently landfilled at a cost to taxpayers but contains 13% phosphorus (P), a limited natural resource required for all living things.  While some have reported that the P in this ash is unavailable for plant uptake, a previous greenhouse study of Twin Cities ash demonstrated that this SSA, as is, could be a safe and available source of P for corn and lettuce.  To follow up, we conducted three years of corn and soybean field studies from 2016-2019 in Rosemount, MN comparing various rates (0 to 180 kg P2O5/ha) of untreated SSA to equivalent rates (based on citrate soluble P) of triple superphosphate, a conventional P-only fertilizer, and two other residual products - Class A EQ (exceptional quality) biosolids and commercially available struvite.  Our objectives were to describe and compare responses from SSA and other P sources to assess the feasibility of SSA as an alternative agricultural fertilizer.  Response variables included harvest yield and plant and soil concentrations of P and other metals of concern.

Our results indicated that SSA as a soil amendment provided comparable amounts of P as the other P sources.  Final 2019 harvest yields in plots amended with SSA or any P source were significantly higher than control plots that had no P applied.  In 2017 and 2018, P uptake increased with increasing application rate, regardless of P source.  Similar trends were found within Bray-P and Olsen-P soil tests, which assess available soil P, and within buried ion exchange resin soil probes.  Except for copper (Cu) and zinc (Zn), no metal of concern was found to have increased significantly in either plant material or the soil.  Soil concentrations of Cu and Zn, but not plant concentrations, increased significantly with increasing rate in plots amended with biosolids and SSA but below levels dangerous to the environment or human health.  Taken together, we believe untreated SSA has the potential to be a safe and viable source of P and an additional option for returning a valuable natural resource to our food system.
Correlation between Arctic river discharge and sea ice formation in Laptev Sea using sea surface salinity from SMOS satellite
Authors: Gabarro Carolina , Martinez Justino , Gonzalez-Gambau Veronica , González-Haro Cristina , Olmedo Estrella , Turiel Antonio , Bertino Laurent , Xie Jiping , Raj Roshin , Catany Rafael , Arias Manuel , Sabia Roberto , Fernandez Diego
Published: March 2020

During the last 3 decades, the Arctic rivers have increased their discharge around 10%, mainly due to the increase of the global atmospheric temperature. The increase of the river discharge carries higher loads of dissolved organic matter (DOM) and suspended matter (SM) entering to the Arctic Ocean. This results in increased absorption of solar energy in the mixed layer, which can potentially contribute to the general sea ice retreat. Observation based studies (e.g. Bauch et al., 2013) showed correlation between river water discharge and local sea ice melting on the Laptev sea shelf due to the change on the ocean heat. Previous studies are based with a limited number of observations, both in space and in time.

Thanks to the ESA SMOS (Soil Moisture and Ocean Salinity) and NASA SMAP (Soil Moisture Active Passive) missions we have daily the sea surface salinity (SSS) maps from the Arctic, which permit to observe the salinity variations due to the river discharges. The Arctic sea surface salinity products obtained from SMOS measurements have been improved considerable by the Barcelona Expert Center (BEC) team thanks to the project Arctic+Salinity, funded by ESA. The new version of the product (v3) covers the years from 2011 up to 2018, have a spatial resolution of 25km and are daily maps with 9 day averages. The Arctic+ SSS maps provide a better description of the salinity gradients and a better effective spatial resolution than the previous versions of the Arctic product, so the salinity fronts are better resolved. The quality assessment of the Arctic+SSS product is challenging because, in this region, there are scarce number of in-situ measurements.

The high effective spatial resolution of the Arctic+ SSS maps will permit to study for the first time scientific physical processes that occurs in the Arctic. We will explore if a correlation between the Lena and Ob rivers discharge with the sea ice melting and freeze up is observed with satellite data, as already stated with in-situ measurements by Bauch et al. 2013. Salinity and sea ice thickness maps from SMOS and sea ice concentration from OSISAF will be used in this study.

 

Bauch, D.,Hölemann, J. , Nikulina, A. , Wegner, C., Janout, M., Timokhov, L. and Kassens, H. (2013): Correlation of river water and local sea-ice melting on the Laptev Sea shelf (Siberian Arctic) , Journal of Geophysical Research C: Oceans, 118 (1), pp. 550-561 . doi: 10.1002/jgrc.20076
Subseasonal prediction of average vs extreme European land temperatures in S2S hindcasts
Authors: Wulff Ole , Domeisen Daniela
Published: March 2020

The prediction of extreme events has been a main focus in subseasonal forecasting due to their potentially high impacts. Despite their undebatable significance, it is not clear that extremes are forecast any better than events close to the mean of the climatology. In our work, we address the question of whether subseasonal forecasting systems show different performance for extreme than for average events. For this, we focus on forecasts of area-averaged European land temperatures in 20 years of hindcasts from the ECMWF system. To compare the prediction skill of extremes at both ends of the distribution to that of average events in summer and winter, we use the Extremal Dependence Index (EDI) which is a forecast performance measure suitable for rare events. Our results suggest that there is higher prediction skill for summer warm extremes as compared to average events at lead times of 3 – 4 weeks, with some regional dependence. The same is not true for summer cold extremes, indicating an asymmetry in the processes causing opposite summer temperature extremes. In winter, our analyses indicate that the situation is reversed: here, the cold events are better predicted. The difference in EDI between extreme and average events is, however, less pronounced than in summer. Further, we find that the forecast performance is strongly improved by the most severe and persistent events inside the analyzed period. We hypothesize that the enhanced warm extreme skill in summer is related to persistent flow patterns and land-atmosphere interaction.
The strength inversion origin of non-volcanic tremor: models and observations
Authors: Morgan Jason P. , de Montserrat Navarro Albert , Vannucchi Paola , Clarke Alexander Peter , Ougier-Simonin Audrey , Aldega Luca
Published: March 2020

Non-volcanic tremor remains a poorly understood form of seismic activity. In its most common subduction zone setting, tremor typically occurs within the plate interface at or near the shallow and deep edges of the interseismically locked zone. Detailed seismic observations have shown that tremor is composed of repeating small low-frequency earthquakes (LFE), often accompanied by very-low-frequency earthquakes (VLF), all involving shear failure and slip. However, LFEs and VLFs within each cluster show nearly constant source durations for all observed magnitudes. This implies asperities of near-constant size,  with recent seismic observations hinting that the failure size is of order ~200m.  

We propose that geological observations and geomechanical lab measurements on heterogeneous rock assemblages representative of the shallow tremor region are most consistent with LFEs and VLFs involving the seismic failure of relatively weaker blocks within a stronger matrix.  Furthermore, in the shallow subducting rocks within a subduction shear channel, hydrothermal fluids and diagenesis have led to a strength inversion from the initial weak matrix with relatively stronger blocks to a stronger matrix with embedded relatively weaker blocks.  In this case, tremor will naturally occur as the now-weaker blocks fail seismically while their more competent surrounding matrix has not yet reached a state of general seismic failure, and instead only fails at local stress-concentrations around the tremorgenic blocks.

Here we use the recently developed code LaCoDe (de Monserrat et al., 2019) to create and explore a wide range of numerical experiments. These experiments are designed to characterize the  likely stress and strain accumulations that can develop in a heterogeneous subduction shear channel, and their implications for the genesis of tremor and its spatially associated seismic events.  In our previous modeling efforts we did not strongly vary either the block volume-fraction or the initial block and matrix geometry. Here we do both, and also explore a range of rock compressibilities ranging from seismically-inferred values to nearly incompressible behavior. We also explore models with irregular 'quasi-geological' initial block/matrix geometries. Drucker-Prager plasticity is used to characterize a fault-like mode of shear failure. This suite of experiments demonstrate that, for a wide range of block and matrix conditions,  the proposed strength-inversion mechanism can generate a mode of shallow tectonic tremor that clusters in spatially discontinuous swarms along the plate interface. At the deeper edge of the interseismically locked zone, channelised dehydration associated with subduction along a plate interface could induce a similar relative strength inversion, and thereby generate deep seated tremor.
Extraction of River Planforms from Synthetic Aperture Radar Imagery using Superpixel Classification
Authors: Pappas Odysseas , Adams Byron , Anantrasirichai Nantheera , Achim Alin
Published: March 2020

Algorithms for the detection and extraction of river planforms from remotely sensed images are of great interest to numerous applications including land planning, water resource monitoring, and flood prediction. Synthetic Aperture Radar (SAR) is a very promising modality for river monitoring and analysis as it can provide high resolution imagery regardless of weather conditions and the day/night cycle.

In this work we present an algorithm for the detection and segmentation of rivers in SAR images, with emphasis on accurate riverbank extraction. The algorithm utilises a novel superpixel segmentation algorithm that segments the image into perceptually uniform clusters of pixels based on a modelling of the SAR data with the Generalised Gamma Distribution.

The generated superpixels adhere to the edges of objects in the image (such as riverbanks) with great accuracy. Superpixels are then characterised according to several features that describe their statistical and textural properties which allows for the discrimination between river- and land-cover superpixels. The river-forming superpixels are then grouped together using unsupervised agglomerative clustering to produce river planform masks.

We demonstrate our proposed method on high resolution SAR images from the SENTINEL-1 and ICEYE platforms. Future work will focus on incorporating more complex heuristics for the identification of false positives and to circumvent apparent river discontinuities (e.g. bridges), as well as on the release of a toolbox providing open access to the geosciences community.
Offshore wind farm far field - Results of the project WIPAFF
Authors: Platis Andreas , Bange Jens , Bärfuss Konrad , Canadillas Beatriz , Hundhausen Marie , Djath Bughsin , Lampert Astrid , Schulz-Stellenfleth Johannes , Siedersleben Simon , Neumann Thomas , Emeis Stefan
Published: March 2020

Wind farm far wakes are of particular interest for offshore installations, as turbulence intensity, which is the main driver for wake dissipation, is much lower over the ocean than over land. Therefore, wakes behind offshore wind turbines and wind parks are expected to be much longer than behind onshore parks. 

In situ measurements of the far wakes were missing before the initiation of the research project WIPAFF (WInd PArk Far Fields) in 2015. The main results of which are reported here. WIPAFF has been funded by the German Federal Ministry for Economic Affairs and Energy and ran from November 2015 to April 2019.  The main goal of WIPAFF was to perform a large number of in situ measurements from aircraft operations at hub height behind wind parks in the German Bight (North Sea), to evaluate further SAR images and to update and validate existing meso-scale and industrial models on the basis of the observations to enable a holistic coverage of the downstream wakes.
 
A  unique  dataset  from  airborne in situ data,  remote sensing  by  laser  scanner  and  SAR  gained  during  the WIPAFF  project  proves  that  wakes  up to  several  tens of kilometers exist downstream of offshore wind farms during stable conditions, while under neutral/unstable conditions, the wake length amounts to 15 km or less. Turbulence occurs at the lateral boundaries of the wakes, due to shear between the reduced wind speed inside the wake and the undisturbed flow. Data also indicates that a denser wind park layout increases the wake length additionally due to a higher initial wind speed deficit. The recovery of the decelerated flow in the wake can be modeled as a first order approximation by an exponential function. The project could also reveal that wind-farm parameterizations in the numerical meso-scale WRF model show a feasible agreement with the observations. 
Optical discrimination of sprite and lightning by use of green light from ~495-505 nm
Authors: Ghilain Simon , Fullekrug Martin , Gordillo Vazquez Francisco José , Sergejevs Aleksandrs
Published: March 2020

Sprites are transient illuminations of the middle atmosphere above thunderclouds which often occur after intense lightning discharges. Here we report optical recordings of sprites and lightning taken with a video camera and photometers in northern Colombia during October 2019.

Optical observations of sprites are often superimposed on the scattered light produced by the parent lightning discharge. This superposition of two optical sources can result in a misinterpretation of the photometer recordings, for example the determination of the rise time of an optical waveform.

Here we propose to use the green light emissions from ~495-505 nm to discriminate between sprite and lightning. This experimental discrimination has become possible because recent modeling studies suggest that lightning emits green light whilst sprite do not emit green light (Gordillo Vazquez et al., 2011; Xue et al., 2015).

The optical signals are detected by a white light video camera and a photometer which is fitted with a ~495-505 nm band pass filter to detect green light. The observed lightning discharges are characterized by significant green emissions in the ~495-505 nm wavelength band. These green emissions are part of the diffuse glow detected by the video camera which is caused by the scattered light from the lightning discharge. This light is scattered during its propagation through the atmosphere which is most likely caused by aerosols, for example related to the ambient humidity and dust. The majority of sprite observations are contaminated by such a diffuse glow with significant ~495-505 nm emissions. The observation of one particular sprite does not exhibit any significant ~495-505 nm emissions and it is therefore attributed to a ‘pure sprite’. The rise time of these optical emissions and the characteristics of other wavelengths recorded by several photometers will be reported for this particularly pure sprite event.

The knowledge gained from these ground-based observations may assist the interpretation of measurements with photometers onboard the ASIM payload on the International Space Station and the forthcoming TARANIS satellite.   

 

 

Gordillo-Vazquez, F.J., Luque, A. and Simek, M.(2011). Spectrum of sprite halos. Journal of Geophysical research, 116, A09319. doi: 10.1029/2011JA016652.

Xue, S., Yuan, P., Cen, J., Li, Y. and Wang, X.(2015). Spectral observations of a natural bipolar cloud-to-ground lightning. Geophysical Research Letters, 120, 1972–1979. doi:10.1002/2014JD022598
Iterative Schwarz Method to Couple Ocean and Atmosphere in a Global Climate Model
Authors: Marti Olivier , Nguyen Sébastien , Braconnot Pascale , Lemarié Florian , Blayo Eric
Published: March 2020

For historical and practical reasons, present-day coupling algorithms implemented in ocean-atmosphere models are primarily driven by the necessity to conserve energy and water at the air-sea interface. However the asynchronous coupling algorithms currently used in ocean-atmosphere do not allow for a correct phasing between the ocean and the atmosphere.

In an asynchronous coupling algorithm, the total simulation time is split into smaller time intervals (a.k.a. coupling periods) over which averaged-in-time
boundary data are exchanged. For a particular coupling period, the average atmospheric fluxes are computed in the atmospheric model using the oceanic surface properties computed and averaged by the oceanic model over the previous coupling period. Therefore, for a given coupling period, the fluxes used by the oceanic model are not coherent with the oceanic surface properties considered by the atmospheric model. The mathematical consistency of the solution at the interface is not guaranteed.

The use of an iterative coupling algorithm, such as Schwarz methods, is a way to correct this inconsistency and to properly reproduce the diurnal cycle when the coupling period is less than one day. In Lemarié et al. (2014), preliminary numerical experiments using the Schwarz coupling method for the simulation of a tropical cyclone with a regional coupled model were carried out. In ensemble simulations, the Schwarz iterative coupling method leads to a significantly reduced spread in the ensemble results (in terms of cyclone trajectory and intensity), thus suggesting that a source of error is removed with respect to the asynchronous coupling case.

In the present work, the Schwarz iterative method is implemented in IPSLCM6, a state-of-the-art global ocean-atmosphere coupled model used to study past, present and future climates. We analyse the convergence speed and the quality of the convergence. A partial iterative method is also tested: in a first phase, only the atmosphere physics and the vertical diffusion terms are computed, until the convergence. This provide a first guess for the full model which is then iterated until convergence of the whole system. The impact on the diurnal cycle will also be presented.
Mangroves as source of alkalinity and dissolved carbon to the coastal ocean: A case study from the Everglades National Park, Florida
Authors: Reithmaier Gloria , Ho David , Johnston Scott , Maher Damien
Published: March 2020

Most research evaluating the potential of mangroves as a sink for atmospheric carbon has focused on carbon burial. However, the few studies that have quantified lateral exchange of carbon and alkalinity, indicate that the dissolved carbon and alkalinity export may be several-fold more important than burial. This study aims to investigate rates and drivers of alkalinity, dissolved carbon and greenhouse gas fluxes of the mangrove-dominated Shark River estuary located in the Everglades National Park in Florida, USA. Time series and spatial surveys were conducted to asses total alkalinity (TAlk), organic alkalinity (OAlk), dissolved inorganic carbon (DIC), dissolved organic carbon (DOC), carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). Dominant metabolic processes driving dissolved carbon and greenhouse gas dynamics varied along the estuary salinity gradient. Dissolved carbon and greenhouse gas concentrations were strongly coupled to porewater input, which was examined using Rn-222. Shark River was a source of CO2 (92 mmol/m­2/d), CH4 (60 µmol/m­2/d) and N2O (2 µmol/m­2/d) to the atmosphere. Dissolved carbon export (DIC = 142 mmol/m­2/d, DOC = 39 mmol/m­2/d) was several-fold higher than burial (~28 mmol/m2/d) and represents an additional carbon sink. Furthermore, the estuary was a source of TAlk (97 mmol/m­2/d) to the coastal ocean, potentially buffering coastal acidification. Despite accounting for only a small share of TAlk, OAlk had a large effect on the estuarine pH. By integrating our results with previous studies, we argue that alkalinity, dissolved carbon and greenhouse gas fluxes should be considered in future blue carbon budgets.
Simulation study on future gravity missions with constellations and formations of small satellites
Authors: Pfaffenzeller Nikolas , Pail Roland , Yunck Tom
Published: March 2020

In the context of an increased public interest in climate-relevant processes, a number of studies on Next Generation Gravity Missions (NGGMs) have been commissioned to better map mass transport processes on Earth. On the basis of the successfully completed gravity field missions CHAMP, GOCE and GRACE as well as the current satellite mission GRACE-FO, different concepts were examined for their feasibility and economic efficiency. The focus is on increasing the spatiotemporal resolution while simultaneously reducing the known error effects such as the aliasing of temporal gravity fields due to under-sampling of signals and uncertainties in ocean tide models. An additional inclined pair to a GRACE-like satellite pair (Bender constellation) is the most promising solution. Since the costs for a realization of the Bender constellation are very high, this contribution focuses on alternative concepts in the form of different constellations and formations of small satellites. The latter includes both satellite pairs and chains consisting of trailing satellites. The aim is to provide a cost-effective alternative to the previous gravity field satellites while simultaneously increasing the spatiotemporal resolution and minimizing the above mentioned error effects. In numerical closed-loop simulations, different scenarios will be performed which differ in orbit parameters like shape and number of orbits, the number of satellites per orbit and their distance to each other as well as the number of inter-satellite links. Additionally, the impacts from the co-parametrization of non-tidal temporal gravity field signal and ocean tides on the gravity field solutions, obtained by the different concepts, will be investigated. 
GSTools: The Python toolbox for your geo-statistical project!
Authors: Müller Sebastian , Schüler Lennart , Zech Alraune , Attinger Sabine , Heße Falk
Published: March 2020

Geo-scientific model development is lacking comprehensive open source tools, that are providing state-of-the art geo-statistic methods. To bridge this gap, we developed a geo-statistical toolbox named GSTools, which is a Python package providing an abundance of methods in a modern object oriented approach. Covered use-cases are:

covariance models (many readily provided and even user-defined models with a lot of functionality)

random field generation (multigaussian and in-compressible vector fields)

field transformations (boxcox, Zinn and Harvey, log-normal, binary)

kriging (simple, ordinary, universal, external drift or detrended)

variogram estimation (Cressie and Matheron estimators)

I/O routines (interfaces to pyvista and meshio for mesh support)

plotting routines (inspect your covariance model or random field on the fly)

GSTools is developed openly within a GitHub organization (https://github.com/GeoStat-Framework). On the one hand to be able to respond to the needs of the modeling community and integrate suggested functionalities and contributions, on the other hand to guarantee stability and reliability of the code-base through continuous-integration features provided by the GitHub infrastructure.

We will present several applications of the mentioned routines to demonstrate the interface and capabilities of GSTools.
Investigating the role of the Cuvette Centrale wetlands in the hydrology, sediment and carbon fluxes of the Congo River basin
Authors: Datok Pankyes , Fabre Clément , Sauvage Sabine , Moukandi Guy , Paris Adrien , Dos Santos Vanessa , Laraque Alain , Sànchez-Pérez José
Published: March 2020

Keywords: Cuvette Centrale, Hydrology, Sediments, Carbon,

The Congo River basin is among the largest Rivers in the world in terms of discharge and drainage area. At the heart of the basin lies the Cuvette Centrale-one of the most extensive wetlands in the world. The increasing pressure on wetland resources continues to threaten the role wetlands play in maintaining water resources and ecological service functions. Therefore, in order to understand the role of the Cuvette Centrale in water resources and ecological service functions linked to the quality of water and life in the basin, we first need to quantify its role in the hydrological, sediment and carbon dynamics. To achieve this aim, we use the Soil and Water Assessment Tool model (SWAT) – modified for tropical environments, in order to analyze the hydrology, sediment and organic carbon fluxes flowing in and flowing out of the Cuvette Centrale of the Congo River basin (CRB). The model was calibrated and validated for the 2000-2006 and 2007-2012 periods respectively by comparing the discharge and sediment output with different data sources (gauging stations and altimetry) at a daily and monthly time step. Then by adapting equations of dissolved organic carbon (DOC) and particulate organic carbon (POC) from literature, we are able to quantify the role of the Cuvette Centrale in the CRB carbon dynamics.The results reveal that the models for hydrology, sediments and carbon can represent both temporally and spatially the exports in a watershed and sheds more light on the important regulatory function of the Cuvette and the need for sustainable land use practices as well as protection of ground water resources  in order to maintain wetland water quantities and quality.
Modes of response of the subsurface western South Atlantic to the last glacial Dansgaard-Oeschger cycles
Authors: Santos Thiago , Ballalai João , Franco Daniel , Oliveira Rômulo , Lessa Douglas , Venancio Igor , Chiessi Cristiano , Kuhnert Henning , Johnstone Heather , Albuquerque Ana Luiza
Published: March 2020

The last glacial was an interval characterized by a sequence of abrupt millennial-scale events well documented mainly from the Greenland and Antarctica ice-cores. Although the triggers are not fully understood, most of the works agree that they occurred in consonance with oscillations in the strength of the Atlantic Meridional Overturning Circulation (AMOC). Paleoceanographic reconstructions have shown that cold millennial-scale stadials were accompanied by high temperatures in the subsurface to intermediate waters of the Atlantic Ocean that may have acted in both the basal melting of ice-sheets and in the rapid atmospheric warming during the onset of warm interstadials. Assuming that recent transient models indicated an accentuated response of the subsurface western South Atlantic to the millennial-scale disturbances, here we present a paleoceanographic reconstruction in this area based on the deep-dwelling planktic foraminifer Globorotalia inflata. Our high-resolution oxygen isotope (d18O) presents a sequence of millennial-scale variability that strongly resembles the structure of the Greenland Dansgaard-Oeschger cycles, mainly during Marine Isotope Stage (MIS) 5. On the other hand, during MIS 3, this millennial-scale feature is absent or weakly represented. Cross-spectral analyzes indicate a meaningful north-to-south forcing over the western South Atlantic subsurface during early-glacial. Mg/Ca-derived temperature and ice-volume free seawater d18O (d18OIVF-SW) executed for the MIS 5 interval demonstrated that the subsurface western South Atlantic was warmer and saltier (colder and fresher) during early glacial stadial (interstadials). We hypothesized that a wide reorganization of the northward heat transport throughout the last glacial occurred, in which regions so far south as 24 ºS worked as prominent heat reservoirs in periods of weakened AMOC during MIS 5 but not necessarily during MIS 3. Our data suggest that future impacts over the AMOC along the Brazilian margin will likely be recognized in the subsurface layers of the western South Atlantic.
High-coercivity magnetic minerals in archaeological ceramics: new insights from remanence acquisition and demagnetization measurements at elevated temperatures
Authors: Kosterov Andrei , Kovacheva Mary , Kostadinova-Avramova Maria , Minaev Pavel , Sal'naya Nataliya , Surovitckii Leonid , Yanson Svetlana , Sergienko Elena
Published: March 2020

The thorough understanding of magnetic mineralogy is a prerequisite of any successful palaeomagnetic, and in particular, archaeomagnetic study. Magnetic minerals in archaeological ceramics and baked clay may be inherited from the parent material, or, more frequently, formed during the firing process. The resulting magnetic mineralogy may be complex, including ferrimagnetic phases not commonly encountered in rocks. Towards this end, we carried out a detailed rock magnetic study on a representative collection of archaeological ceramics (baked clay from combustion structures and bricks) from Bulgaria and Russia. Experiments included measurement of isothermal remanence acquisition and demagnetization as a function of temperature between 20°C and >600°C, and a variant of Lowrie 3-axis IRM test with measurements performed at elevated temperatures. For selected samples, low-temperature measurements of saturation remanence and initial magnetic susceptibility between 1.8 K and 300 K have been carried out.
All studied samples contain a magnetically soft mineral identified as maghemite probably substituted by Al and/or Ti. Stoichiometric magnetite has never been observed, as evidenced by the absence of the Verwey phase transition. In addition, one or two magnetically hard mineral phases have been detected, differing sharply in their respective unblocking temperatures. One of these unblocking between 540°C and 620°C is believed to be substituted hematite. Another phase unblocks at much lower temperatures, between 140°C and 240°C, and its magnetic properties correspond to an enigmatic high coercivity, stable?, low unblocking temperature (HCSLT) phase of McIntosh et al. [McIntosh, G., M. Kovacheva, G. Catanzariti, M. L. Osete, and L. Casas (2007), Geophys. Res. Lett., 34, L21302, doi: 10.1029/2007GL031168]. In a few samples high- and low-unblocking temperature magnetically hard phases appear to coexist, in the others the HCSLT phase is the only magnetically hard mineral present. We finally compare the samples performance in archaeointensity experiments with their respective magnetic mineralogy.
This study is supported by Russian Foundation of the Basic Research, grant 19-55-18006, and Bulgarian National Science Fund, grant KP-06-Russia-10.
Prospecting alpine permafrost with Spectral Induced Polarization in different geomorphological landforms
Authors: Maierhofer Theresa , Katona Timea , Hilbich Christin , Hauck Christian , Flores-Orozco Adrian
Published: March 2020

Permafrost regions are highly sensitive to climate changes, which has significant implications for the hydrological regimes and the mechanical state of the subsurface leading to natural hazards such as rock slope failures. Therefore, a better understanding of the future evolution and dynamics of mountain permafrost is highly relevant and monitoring of the thermal state of permafrost has become an essential task in the European Alps. Geophysical methods have emerged as well-suited to support borehole data and investigate the spatial distribution and temporal changes of temperature and the degradation of permafrost. In particular, electrical resistivity tomography (ERT) has developed into a routine imaging tool for the quantification of ice-rich permafrost, commonly associated with a significant increase in the electrical resistivity. However, in many cases, the interpretation of the subsurface electrical resistivity is ambiguous and additional information would improve the quantification of the ice content within the subsurface. Theoretical and laboratory studies have suggested that ice exhibits a characteristic induced electrical polarization response. Our results from an extensive field programme including many morphologically different mountain permafrost sites now indicate that this IP response may indeed be detected in the field suggesting the potential of the Induced Polarization (IP) method to overcome such ambiguities. We present here Spectral IP (SIP) mapping results conducted over a broad range of frequencies (0.1-225 Hz) at four representative permafrost sites of the Swiss-, Italian- and Austrian Alps. The mapping results have been used to install long-term permafrost monitoring arrays for a better understanding of subsurface variations associated to climate change. All SIP study sites are located at elevations around 2600 - 3000 m and include comprehensive geophysical and temperature data for validation. We focus on the spatial characterization of each site to address different research questions: to (i) reproduce and improve the mapping of the spatial permafrost extent inferred from previous investigations in the Lapires talus slope,Western Swiss Alps, to (ii) improve the geophysical characterization of the Sonnblick monitoring site located in the Austrian Central Alps, to (iii) determine the transition between permafrost and non-permafrost at the Schilthorn site, Bernese Alps, Switzerland, and to (iv) find the best-suited location for a SIP monitoring profile and conduct year-round measurements at the Cime Bianche site, Western Italian Alps. Our various field applications demonstrate the potential of the IP method for characterizing and monitoring permafrost systems in high-mountain environments.
The role of teleconnection patterns in the increased drought frequency in Mediterranean climate: Some hints from central Italy
Authors: Romano Emanuele , Salerno Franco , Petrangeli Anna Bruna , Guyennon Nicolas
Published: March 2020

Central Italy presents numerous factors potentially affecting the precipitation regime: 1) it includes both Tyrrhenian and Adriatic sides, the first exposed to Atlantic perturbation and generally more rainy, the second one possibly exposed also to Balkan streams; 2) due to the short distance between the two coasts (few tens of kilometres), also the more internal areas are prone to the influence of the sea; 3) at the same time, the highest reliefs of the Apennine chain are located in the region; 4) the Northern areas of the Adriatic side experience the influence of the continental climate, due to the Po Valley. The climate framework Central Italy sees in the last thirty years a tendency toward drier conditions and an increasing of drought events, mostly in frequency. To explore the variability in time and space of the precipitation regime in relation to the atmospheric patterns, land rainfall data collected and homogenised trough geostatistical approach over the period 1951-2019 in Central Italy have been analysed in relation to the following indexes: Winter NAO index, East Atlantic-West Russia index, Pacific/North America index, Polar/Eurasia index, Scandinavian index, Artic oscillation index, Western Mediterranean oscillation index. Focus of the analysis (1951-2019) is put on possible common signal between precipitation regime anomalies (on both Tyrrhenian and Adriatic side) and teleconnection patterns, sought through regression analysis and a wavelet and cross-wavelet decomposition. Results indicate that possible influence of some teleconnection patterns (particularly East Atlantic, East Atlantic/Western Russia and NAO) on the precipitation regime is limited to winter and early spring for the Tyrrhenian side, and to summer for the Adriatic side. Moreover, the analysis of the mean wavelet time series-period indicates an increasing in frequency of drought episodes for the last 20 years on both sides of the study area.