bluuebunny/crossref_metadata_2025 huggingface dataset:
Volcanism and Rodent Evolution: ecological interactions in different geological provinces in America discussion from a workshop 
Authors: Pacheco Castro Adolfo , Arroyo Cabrales Joaquín , Fox David , Hopkins Samantha , Badgley Catherine
Published: March 2022

Terrestrial biodiversity is higher in topographically complex regions than in low relief ones, and this diversity evolved over millions of years along elevation gradients with disequilibrium of climatic conditions and biological interactions. Also, the mountainous complex is heterogeneous, consisting of orogenic and volcanic mountains with different geological and climatic features. However, there has not been an investigation in regard how a volcanic environment may have influenced ecosystem changes or faunal evolution to. Rodents are an excellent model to explore these questions because they are the most speciose clade of mammals and many species live in montane regions. Hypotheses of the ecological evolution in different volcanic provinces in America were discussed during the Workshop on Volcanism and Rodent Evolution organized by the Research Group “Mammal diversification about dynamic landscapes of the North American Rodents Landscapes, Evolution & Ecology”. Workshop consisted of two modules: 1) origin and development of volcanic provinces in North America during the late Cenozoic with an emphasis on the geological process crucial to the ecosystem; 2) some examples of ecosystems in volcanic regions and evolutive patterns related to sky-island process. In both modules, we discuss the evolution of different lineages of rodents, fossil and extant species, and how we can distinguish the volcanic influence on their biodiversity. The topics were: speciation, endemism, genetic drift, geographic-range shifts, environmental sorting, and sky-island processes.
Assessing the oxidative damage potential of engineered stone dust using a deoxyguanosine assay
Authors: Thredgold Leigh , Ramkissoon Chandnee , Kumarasamy Chellan , Gun Richard , Rowett Shelley , Gaskin Sharyn
Published: March 2022

The popularity of engineered stone (ES), alternatively known as artificial stone, as a building material for kitchen and bathroom benchtops in residential houses has expanded rapidly over the last decade. This has been associated with a global increase in occupational lung disease in workers exposed to the respirable dust produced during fabrication of ES products. In this study, we evaluated the reactivity and subsequent oxidative reduction potential of ES dusts generated by dry-cutting different ES materials using a common fabrication tool in a controlled environment and subsequently applying these freshly generated dusts to a cell-free deoxyguanosine hydroxylation assay to assess the potential for oxidative DNA damage. The objectives of this study were to (1) compare the potential for oxidative damage by (i) engineered vs. natural stones, (ii) settled vs. respirable stone dust fractions and (2) assess the effect of ageing on the reactivity of freshly-generated stone dust. Engineered stone dust was found to exhibit a higher relative reactivity than the majority of natural stones tested.  Respirable dust fractions were found to be significantly more reactive than their corresponding settled fraction (p<0.05), across all stone types and samples. However, settled dusts still displayed relatively high reactivity overall. No significant change in respirable dust reactivity was observed for three ES samples over a 21-day period; whereas a significant decrease in reactivity was observed in the natural stone studied. These results indicate that ES dusts are able to maintain their relatively high reactivity for extended time periods and settled dust fractions remain a significant hazard if resuspended within the workplace. This study has practical implications for dust control and housekeeping in industry, risk assessment and management.
Data-driven Reconstruction of Last Glacials' Climate Dynamics Suggests Monostable Greenland Temperatures and a Bistable Northern Hemisphere Atmosphere
Authors: Riechers Keno , Rydin Leonardo , Hassanibesheli Forough , Witthaut Dirk , Lind Pedro , Boers Niklas
Published: March 2022

Multiple proxy records from Greenland ice cores exhibit a series of concomitant abrupt climatic shifts during the last glacial. These so-called Dansgaard–Oeschger (DO) events comprise, among others, warming over Greenland, a sudden retreat of North Atlantic and Nordic Seas’ sea ice, and an atmospheric reorganisation of hemispheric extent. Typically DO events are followed by a phase of moderate cooling, before the climate abruptly transition back to its pre-event state. While the physics behind these dynamics are still subject to a vibrant debate, the idea that at least one of the involved climatic subsystems features bistability is widely accepted.

We assess the stability of Greenland temperatures and the Northern Hemisphere atmospheric circulation represented by δ¹⁸O and dust concentration records from the NGRIP ice core, respectively. We investigate the 27-59 ky b2k period of the combined record which covers 12 major DO events at high temporal resolution. Regarding the data as the realisation of a stochastic process we reconstruct the corresponding drift and diffusion by computing the Kramers–Moyal (KM) coefficients. In contrast to previous studies, we find the drift of the δ¹⁸O to be monostable, while analysis of the dust record yields a bistable drift. Furthermore, we find a non-vanishing 4th-order KM coefficient for the δ¹⁸O, which indicates that the δ¹⁸O time series cannot be considered a standard type Langevin process. In a second step, we treat the joint (δ¹⁸O , dust) time series as a two dimensional stochastic process and compute the corresponding coefficients of the two dimensional KM expansion. This reveals the position of the fixed point of δ¹⁸O to be controlled by the value of the dust. In turn, the drift of the dust undergoes an imperfect supercritical pitchfork bifurcation when transitioning from low to high δ¹⁸O values.
A volcano seismic monitoring network in the Caribbean Netherlands
Authors: Sleeman Reinoud , de Zeeuw-van Dalfsen Elske
Published: March 2022

The Lesser Antilles volcanic arc on the eastern boundary of the Caribbean Plate is part of the Caribbean subduction zone. The subduction process is responsible for the formation of 16 volcanoes in this arc, forming islands like Saba and St. Eustatius in the Caribbean Netherlands. KNMI deploys a monitoring network on these islands consisting of seismometers and GNSS stations. The seismic network is built with broadband seismometers to monitor seismic signals from (regional) earthquakes and from volcano related processes at Saba and St. Eustatius. We use local infrastructure as well as stand-alone VSAT technology to transmit seismic data in near real-time to KNMI. Data are forwarded in real-time to the Pacific Tsunami Warning Center (PWTC). Waveforms are openly available to the research community through ORFEUS/EIDA, and through EPOS-NL, a Dutch national research infrastructure for solid Earth science that integrates large-scale geophysical facilities in the Netherlands.

Volcanoes Mt. Scenery (Saba) and The Quill (St. Eustatius) are active but quiescent. Volcanic earthquakes may occur at different depths and are caused by various processes in a volcano. Each type of volcanic earthquake exposes differences in features in the waveform data, like frequency content, waveform envelope, duration, statistical parameters and type of onset. We are building a monitoring system based on various tools and techniques, like a) SeisComP3 for detecting and locating regional tectonic earthquakes, b) a coincidence trigger to detect small, local (volcanic) earthquakes, c) covariance matrix analysis to identify coherent signals across the network, d) seismic interferometry to monitor seismic velocity changes in the subsurface of the volcanoes and e) data quality monitoring  to ensure high quality of data.

We provide an overview of the seismic network, the infrastructure, the availability of data through EPOS-NL and the implementation of the various monitoring techniques.
A graphical user interface for probabilistically predicting equilibrium ripple wavelength
Authors: Phillip Ryan , Penko Allison , Palmsten Margaret
Published: March 2022

Decades of study have gone into better understanding seafloor geomorphic features like sand ripples due to their effect on acoustic scattering, sediment resuspension, and sediment transport. Most of this previous research resulted in deterministic empirical equilibrium ripple formulations, generated from performing regressions on data with large amounts of scatter, with no measure of uncertainty. However, the relatively recent rise of machine learning has provided techniques to greatly advance oceanic and coastal marine predictive modeling. Utilizing the machine learning method of stacked generalization, the Bayesian Optimal Model System (BOMS) combines two deterministic empirical ripple equations and two machine learning algorithms with a Bayesian meta-learner to produce probabilistic predictions of equilibrium ripple wavelength. BOMS was trained with over 50 years of wave and ripple observations and can be used to produce predictions in its pre-trained state, or can be re-trained and optimized with additional observations. A graphical user interface (GUI) was created to increase the accessibility of the model system. From the GUI, the user can perform the required data pre-processing for both producing predictions and for adding training data and re-optimizing the system. The GUI output includes scatter and/or timeseries plots of predictions vs. observations, a probability distribution plot of predicted ripple wavelength for each observation in the user’s dataset, a numerical dataset of the prediction probabilities, a dataset of a user-defined number of BOMS realizations for each observation in the user’s dataset, or any combination of those options. BOMS has the flexibility to be used either as a standalone program to predict the probability distributions of equilibrium ripple wavelengths given wave conditions or coupled with other coastal hydrodynamic and acoustic models to produce realizations of resulting ripples for estimations of seafloor roughness.
Seasonal cycle of the overturning circulation in the subpolar North Atlantic
Authors: Fu Yao , Lozier M. Susan ,   OSNAP Team
Published: March 2022

Understanding the mechanisms driving variability in the Atlantic Meridional Overturning Circulation (AMOC) on different timescales is essential for better predictions of our evolving climate. The newly updated time series (August 2014 to June 2020) from OSNAP (Overturning in the Subpolar North Atlantic Program) continues to reveal strong intra-annual and interannual variability. However, this six-year record allows us, for the first time, to examine the observation-based seasonal variability of the subpolar overturning circulation. We find that the overturning peaks in late spring from April through June and reaches the minimum in winter for both OSNAP West (a section from the coast of Labrador to West Greenland) and OSNAP East (a section from East Greenland to the Scottish shelf). An analysis of seasonality in the Labrador Sea (OSNAP West) suggests that the delay between wintertime transformation and the observed overturning peak in late spring is consistent with the advection and export of dense Labrador Sea Water along the western boundary. Further analysis is required to understand the mechanism driving seasonal overturning across OSNAP East.
Long-term field studies in Canada on monitoring pedogenic carbonate formation in agricultural soils via enhanced weathering of wollastonite: status and latest findings
Authors: Khalidy Reza , Chiang Yi Wai , Santos Rafael M
Published: March 2022

Among the several methods that have been proposed for mitigating carbon concentration in the atmosphere, enhanced rock weathering is regarded as a low-cost, low-energy and readily scalable approach that can store atmospheric CO2 for up to thousands of years through converting alkaline earth metals into stable carbonates. Application of silicate-rich minerals (e.g., wollastonite, basalt and olivine) has been found effective for capturing atmospheric carbon in different terrestrial mediums, including agricultural and urban soils.

In Ontario, Canada, we have been performing long-term research on pedogenic carbonate formation in agricultural soils amended with crushed wollastonite/dolomite rock mined in Ontario. The mineral has been applied to the topsoil of a number of experimental and farming fields, and shallow soil samples are periodically collected at different depths (including 0-15 cm, 15-30 cm, 30-60 cm, and 60-100 cm profiles) from these plots in order to estimate the rate and amount sequestrated carbon, and its migration across soil/sub-soil horizons over several years.

These experiments are part of our effort to develop analytical and modeling toolboxes for verifying soil inorganic carbon sequestration, in view of qualifying this practice for carbon credits. Such toolboxes can become valuable for private and governmental entities in contributing to meet emissions reduction goals, and in encouraging the adoption of ERW as a reliable and verifiable negative emissions technology. This presentation will present the status of the field trials and toolbox development, and our latest findings and research directions.
Simplified Relations for the Martian Nighttime Hydroxyl Layer Suitable for Interpretation of Observations
Authors: Shaposhnikov Dmitry , Grygalashvyly Mykhaylo , Medvedev Alexander S. , Sonnemann Gerd Reinhold , Hartogh Paul
Published: March 2022

Observations of excited hydroxyl (OH*) emissions are broadly used for inferring information about atmospheric dynamics and composition. It plays an important role in the photochemical balance and is affected by transport and mixing processes. We present several analytical approximations for characterizing the hydroxyl layer in the Martian atmosphere. They include OH* number density at the maximum and the height of the peak, along with the relations for assessing different impacts on the OH* layer at nighttime conditions. These characteristics are determined by the ambient temperature, atomic oxygen concentration and their vertical gradients. The derived relations can be used for analysis of airglow measurements and interpretation of its variations.
Multiple intertidal bars: Three years of cross-shore and longshore dynamics
Authors: Biausque Melanie , Grottoli Edoardo , Jackson Derek , Cooper Andrew
Published: March 2022

Multiple Intertidal bars (MITB) are complex features described as a succession of sandbars located within the intertidal area of meso- to macrotidal beaches. Despite being found in many locations where conditions allow, the dynamics of these coastal bedforms remain unclear. They appear to be long-term features, relatively stable in form, but at the same time their movements can be prone to strong, short-term dynamics. MITB can play a significant role in wave energy dissipation as well as helping protect the beach/dune system to energetic events. In the context of sea level rise, our understanding of their behaviour over short to longer timescales, is important for coastal management and adaptation planning.

Three years of monthly DGPS surveys, conducted in Dundrum Bay (Northern Ireland) from May 2019 to April 2022, along with analysis of offshore wave forcing, were investigated to characterise both cross-shore and longshore dynamics. Additional cross-shore profiles were recorded every 10m to gather more detailed topographical understanding of changes in the intertidal. From interpolated topographic surveys, we identify complex sediment exchanges between the dune, the upper and intertidal beach areas. In addition, survey-to-survey difference maps as well as cross-shore profiles, were used to track cross-shore migrations of sandbars across the intertidal areas.

Preliminary results suggest that both incident wave energy and its direction are key hydrodynamic forcing variables that drive cross-shore migrations. Understanding sediment exchange between the different cross-shore sections of the beach is however, more complex and still under investigation.

Cross-shore drainage channels, essential in evacuating water-excess during tidal ebb, were observed intersecting bars at several locations. The evolution of these channels was closely associated with the alongshore migrations of bars. Cross-shore channels show a migration towards the inlet, that separates two main sections of the site, suggesting a migration of MITB bars towards the inlet. Consequently, a longshore sediment transport takes place from each sides of the bay toward the inlet, highlighting the significant role the inlet has in sediment circulation cells within Dundrum Bay.
Impacts of insolation and CO2 on the spatial differences of the MIS-9 and MIS-11 climate between monsoonal China and central Asia 
Authors: Lu Hao , Yin Qiuzhen , Wu Zhipeng , Shi Feng , Hao Qinzhen , Xia Dunsheng , Guo Zhengtang
Published: March 2022

Marine oxygen isotope records and ice cores in Antarctica suggest that Marine Isotope Stage (MIS) 9, an interglacial occurring about 300 ka ago, is a strong interglacial and has the highest greenhouse gases (GHG) concentrations during the past 800 ka. Model results also show that MIS-9 is the warmest interglacial among the last nine ones as a result of both its high CO2 concentration and its high summer insolation in the northern Hemisphere (NH). However, the China loess records show that the paleosol S3 that corresponds to MIS-9 is not necessarily strong as compared to some other paleosol units such as the S4 soil that was formed during MIS-11, suggesting relatively drier climate condition during MIS-9. By contrast, in Tajikistan of southern central Asia, the paleosol S3 is the most developed soil over the past 800 ka, indicating a relatively warm and humid climate conditions. The difference in the paleosol formation and the MIS-9 climate between monsoonal China and central Asia is intriguing. In this study, we combine loess records from monsoonal China and central Asia as well as climate simulation results to understand the spatial difference of the MIS-9 climate in particular in comparison with the climate of MIS-11. The individual and combined contributions of insolation and greenhouse gases are quantified through simulations with the LOVECLIM model and using the factor separation technique. Our results show that the simulated effective moisture conditions between northern China and southern central Asia are consistent with the loess records and field observation. Insolation leads to much more annual mean precipitation than GHG during MIS-9 in southern central Asia, explaining a much wetter MIS-9 there. By contrast, both insolation and GHG lead to more annual mean precipitation and evaporation during MIS-9 in northern China, leading to only a slight difference in the effective moisture between MIS-9 and MIS-11. In addition, compared to MIS-11, the larger obliquity and higher GHG concentration during MIS-9 lead to an anomalous atmospheric circulation pattern similar to negative phase of North Atlantic Oscillation (NAO), favoring precipitation increase in southern central Asia and therefore explain strong soil development in Tajikistan.
Clustering stream profiles to understand the geomorphological features and evolution of the Yangtze River by using DEMS
Authors: Zhao Fei , Xiong Liyang
Published: March 2022

Stream morphology is an important indicator for revealing the geomorphological features and evolution of the Yangtze River. Existing studies on the morphology of the Yangtze River focus on planar features. However, the vertical features are also important. Vertical features mainly control the flow ability and erosion intensity. Furthermore, traditional studies often focus on a few stream profiles in the Yangtze River. However, stream profiles are linked together by runoff nodes, thus affecting the geomorphological evolution of the Yangtze River naturally. In this study, a clustering method of stream profiles in the Yangtze River is proposed by plotting all profiles together. Then, a stream evolution index is used to investigate the geomorphological features of the stream profile clusters to reveal the evolution of the Yangtze River. Based on the stream profile clusters, the erosion base of the Yangtze River generally changes from steep to gentle from the upper reaches to the lower reaches, and the evolution degree of the stream changes from low to high. The asymmetric distribution of knickpoints in the Han River Basin supports the view that the boundary of the eastward growth of the Tibetan Plateau has reached the vicinity of the Daba Mountain.
Facilitating the development of complex models with the Common Community Physics Package and its Single-Column Model
Authors: Bernardet Ligia , Firl Grant , Heinzeller Dom , Zhang Man , Trahan Sam , Dudhia Jimy , Kavulich Mike , Ek Mike
Published: March 2022

The Common Community Physics Package (CCPP) is a collection of atmospheric physical
parameterizations and a framework that couples the physics for use in Earth system models.
The CCPP Framework was developed by the U.S. Developmental Testbed Center (DTC) and is
now an integral part of the Unified Forecast System (UFS), a community-based, coupled,
comprehensive Earth modeling system designed to support research and be the source system
for NOAA‘s multi-scale operational numerical weather prediction applications.

A primary goal for this effort is to facilitate research and development of physical
parameterizations, while simultaneously offering capabilities for use in operational models. The
CCPP Framework supports configurations ranging from process studies to operational
numerical weather prediction as it enables host models to assemble the parameterizations in
flexible suites. Framework capabilities include flexibility with respect to the order in which
schemes are called, ability to group parameterizations for calls in different parts of the host
model, and ability to call some parameterizations more often than others. Furthermore, the
CCPP is distributed with a single-column model that can be used to test innovations and to
conduct hierarchical studies in which physics and dynamics are decoupled.

There are today more than 30 primary parameterizations in the CCPP, representing a wide
range of meteorological and land-surface processes. Experimental versions of the CCPP also
contain chemical schemes, making it possible to create suites that tightly couple chemistry and
meteorology.

The CCPP is developed as open-source code and has received contributions from the wide
community in the form of new schemes and innovations within existing schemes. In this poster,
we will provide an update on CCPP development and plans, as well as review existing
resources for users and developers, such as the public releases, documentation, tutorial, and
forum
Research on texture features for typical sand dunes using multi-source data
Authors: Ma Junfei , Li Fayuan , Liu Lulu , Cheng Jianhua , Tang Guoan
Published: March 2022

Deserts have obvious textural features. In detail, different types of sand dunes have significant differences in their morphological texture features. Existing studies on desert texture have mainly focused on extracting dune ridges or sand ripples using remote sensing images. However, comprehensive understanding of desert texture at multiple scales and quantitative representation of texture features are lacking. Our study area is in the Badain Jaran Desert. Four typical sand dunes in this desert are selected, namely, starlike chain megadune, barchans chain, compound chain dune, and schuppen chain megadune. Based on Sentinel-2 and ASTER 30m DEM data, the macroscopic and microscopic texture features of the desert are extracted using positive and negative topography, edge detection and local binary pattern (LBP) methods, respectively. Eight texture indexes based on gray level co-occurrence matrix(GLCM) are calculated for the original data and the abstract texture data respectivelyThen these texture parameters are clustered based on the result of Spearman correlation. Finally, the coefficient of variation is used to determine representative indicators for each cluster in order to construct a geomorphological texture information spectrum library of typical dune types. The results show that the macroscopic and microscopic texture features of the same type of sand dunes have high similarity. And geomorphological texture information spectrum can well distinguish different types of sand dunes by curve features.
Seepage loss from unlined, lined, and cracked-lined canals: a case study of Ismailia canal reach from 28.00–49.00 Km, Egypt
Authors: Elkamhawy Elsayed , Zelenakova Martina , Straface Salvatore , Vranayová Zuzana , Negm Abdelazim M. , Scozzari Andrea , Abd-Elaty Ismail
Published: March 2022

Water resources face global and local challenges. In Egypt, for example,  the negative impacts of climatic changes and the Grand Ethiopian Renaissance Dam (GERD), cause a shortage of water resources. Shortage of water resources is considered an urgent issue particularly in semiarid regions (like many MENA countries) and arid ones (like Egypt). Therefore, the Egyptian Ministry of Water Resources and Irrigation has launched the national project of canals rehabilitation and lining for effective water resource management and decreasing seepage losses. This study dealt with three different lining techniques, as well cracked-liner for the Ismailia canal, which is considered the largest end of the Nile in Egypt. A steady-state 2-D seep/w model was established for the Ismailia canal section, at the stretch from 28  to 49 km. The results showed that the amount of seepage was considerably depending on the hydraulic characteristics of the lining material. Pumping from aquifers through wells also has a significant influence on the seepage rate from the unlined canal. Nevertheless, a negligible effect was present in the lined canal case. The highest efficiency was obtained with the concrete liner, after that the geomembrane liner, and then the bentonite liner; with nearly 99%, 96%, and 54%, respectively, in the case of no pumping from aquifer via wells. The efficiency decreased by 4% for the bentonite and geomembrane liners during pumping from the aquifer, but the concrete liner efficiency did not change significantly. However, in the case of deterioration of the lining material through cracks, the efficiency strictly decreased to 25%, irrespective of the utilized lining technique. The dual effect of both cracked-liner material and extraction from the aquifer via pumping wells revealed an efficiency of 16%, regardless of the utilized liner type.
Geomorphic and stratigraphic evolution of floodplain lakes in the Central Ganga Plains, India
Authors: Misra Pavani , Singh Manudeo , Tandon Sampat Kumar , Sinha Rajiv
Published: March 2022

The floodplains of the mighty river Ganga are centrally located in the Himalayan foreland basin and act as temporary storehouse for sediments eroded and transported from the Himalayan mountains. This fluvial landscape provides sufficient groundwater and fertile lands that support the agricultural activities to sustain the livelihood of a vast population. The Ganga plains exhibit a broad array of geomorphic features associated with the fluvial environment of deposition. The interfluve between the Ganga and Sai rivers in the Central Ganga Plains has been documented to be the oldest geomorphic surface in the region. Narrow meandering loops of streams, stretches of linear lakes representing sinuous abandoned channels and meander cut-offs, small ponds, and oxbow lakes can be observed in the elevated interfluve of both these rivers. The presence of numerous oxbow lakes and small isolated pools as remnants of the abandoned channels is a testimony to a highly active fluvial setting in the past.
In order to understand the evolution of the linear belt of meander cut-offs and oxbows in the Ganga-Sai interfluve, both regional and local scale geomorphic mapping was done using the earth observation satellite imageries and a multi-temporal approach was followed to efficiently trace all the observable geomorphic features in this fluvial setting. The regional scale geomorphic mapping of this interfluve shows a linear paleochannel belt comprised of meander cutoffs and small abandoned channel segments run parallel to the present-day Sai river. A large oxbow lake (Baraila Tal) was selected from this linear belt of cutoffs and excavated at three locations to investigate the chrono-stratigraphic succession of these lakes. Results from the geomorphic analysis suggest that the belt of paleochannel remnants was previously a part of the avulsed channel of Sai river. Three stages of landscape evolution and development of various geomorphic features related to channel migration between the Late Pleistocene and Holocene period in the Ganga-Sai interfluve region in the Central Ganga Plains have been identified. Stratigraphic succession at Baraila Tal shows the presence of micaceous sandy material at the base which suggests that the lake was previously a part of an active fluvial system. This litho-unit is overlain by the finer clayey silt and silty clay deposits which indicate that the depositional environment transformed from a fluvial to a lacustrine system. The proposed evolutionary pathway has been validated using results of stable isotopic data generated from the micro-gastropod shells picked from the lake sediments of Baraila Tal in the Ganga-Sai interfluve.
Large-scale PIC Simulations of the Interaction of Solar Wind Discontinuities with the Dayside Magnetopause
Authors: Berchem Jean , Lapenta Giovanni , Richard Robert L. , Escoubet C.-Philippe , Wing Simon
Published: March 2022

Developing an understanding of the effects of solar wind structures on the dayside magnetopause is a necessary first step for comprehending how they impact the magnetosphere.  With this aim, we have used large-scale particle-in-cell (PIC) simulations to investigate the kinetic processes occurring at the magnetopause as solar wind structures impact the dayside magnetosphere.  In this presentation, we report our progress in investigating the interaction of simple discontinuities with the magnetopause.  Our procedure is to first run a global magnetohydrodynamic (MHD) simulation to predict the overall configuration of the solar wind-magnetosphere system before the impact of the discontinuity on the magnetopause. Then, fields and plasma moments within a large sub-domain of the global MHD simulation are used to set the initial conditions of the implicit PIC simulation of the impact. Preliminary results indicate that the interactions of solar wind discontinuities with the magnetopause are very likely to generate a succession of large magnetic flux ropes that move toward the cusps. The simulations reveal the development of a strong North-South asymmetry in the twisting of the ropes. This suggests that we should expect strong North- South asymmetries in particle precipitation when such discontinuities impact the magnetopause.
Monitoring microplastics and their associated chemicals in an Irish deep water Special Area of Conservation
Authors: Mateos Cardenas Dr Alicia , Wheeler Andy , Lim Aaron
Published: March 2022

Although microplastic pollution is ubiquitous, accurate quantification is still required and plastic associated chemicals from environmental samples remain largely unexplored. Given the difficulties associated with deep water data acquisition (e.g. costly and opportunistic sampling, weather dependency and engineering restrictions), much of the research carried out on marine plastics to date are either restricted by low spatial or temporal resolution, are isolated studies or are subject-specific in nature due to a lack a multidisciplinary approach. Preliminary video data collected by a Remotely Operated Vehicle (ROV) from an earlier project led by the team previously showed that large plastic items are abundant, especially fishing items, in deep water Irish coral reefs from the Porcupine Bank Canyon and Moira Mounds, both currently listed as Special Areas of Conservation (SACs). This study expands on such previous knowledge of the area and focusses on microplastics by integrating a large spatial range, temporal resolution and novel methodologies. Microplastics and their associated chemicals are being analysed from samples collected by eight Benthic Lander systems and sediment traps deployed between 2019 to 2021. QA/QC techniques are given special importance to ensure the reliability of the analytical results produced. The main outcomes of this study are to (1) accurately quantify the abundance and fate of microplastics and their associated chemicals in deep sea Irish canyons, (2) the interactions and impacts to the health of cold-water corals present in Special Areas of Conservation (SACs) and (3) the potential cause for observed coral health variability throughout time.
The DR-D experiment in the Mont-Terri rock laboratory, heterogeneity of the Sandy Facies of Opalinus Clay across scales, from seismic surveys to radionuclide diffusion
Authors: Heberling Frank , Albers Hendrik , Beilecke Thies , Deissmann Guido , Furche Markus , Geckeis Horst , Hoyer Eva Maria , Joseph Claudia , Liebscher Axel , Lüth Stefan , Metz Volker , Müller Katharina , Nowak Ulf , Rebscher Dorothee , Schulte Friedhelm , Steegborn Florian , Tietz Torsten
Published: March 2022

Clay rocks are investigated as potential host rocks for high-level nuclear waste (HLW) repositories in many countries. The Sandy Facies of Opalinus Clay (SF-OPA), as accessible in the Mont Terri rock laboratory, exhibits a pronounced heterogeneity, which is as well expected for lower cretaceous clay rocks, that are among the potential host rocks for the German HLW repository.

Aim of the DR-D experiment is to characterize the heterogeneity of SF-OPA on the m-cm scale via seismic tomography and borehole seismic characterization. Borehole logging and ex-situ drill core characterization provide information on rock heterogeneity on smaller scales.

Within the area, characterized by seismic tomography, a radio-tracer diffusion experiment will be set up, with the aim to correlate the observed diffusion behavior with the heterogeneous rock structure.

The first drilling campaign took place in May 2021. The seismic tomography survey of the experimental area was performed in October 2021. Processing and analysis of the seismic data, as well as drill core characterization are currently underway.

In this contribution we present the general concept and layout of the DR-D experiment, as well as first results.

We acknowledge funding by the German Federal Ministry of Education and Research (BMBF) (Grant 02NUK053A-E), the Helmholtz Association (Grant SO-093), BGR, and BGE. Special thanks to swisstopo and the Mont-Terri project for help, advice, and support.

 
Transient response of surface-forced water mass transformation over the Southern Ocean and its connection to overturning and ventilation
Authors: Tesdal Jan-Erik , MacGilchrist Graeme A. , Beadling Rebecca. L. , Krasting John P. , Griffies Stephen M.
Published: March 2022

The water mass transformation (WMT) framework provides a useful perspective on interior ocean circulation because it combines the influence of surface forcing and diapycnal mixing with overturning. Observational analyses, as well as the majority of ocean model diagnostics, only adequately resolve surface-forced transformation of water masses and rely on inference or rough approximations to quantify the effect of the interior transformation term due to mixing. Here we characterize the connection between surface-forced WMT and meridional overturning of the Southern Ocean in two state-of-the-art GFDL coupled climate models. We assess the mean state of the system as well as the transient response to changes in surface forcing. For the latter, we analyze a set of idealized perturbation experiments in which changes in Antarctic ice sheet melting and Southern Ocean wind stress are imposed. Assessment of the mean state in the two climate models is consistent with previous studies that identified overturning as a balance between surface and interior WMT, with the surface component being the dominant term. However, the perturbation runs in both models demonstrate important differences in the response of surface WMT and meridional overturning. Changes in overturning are consistent with surface WMT but are muted in terms of intensity, location, and the density at which they occur. This points to a crucial role for interior WMT associated with mixing, as well as changes in water mass volumes, which are important terms in characterizing anticipated shifts in overturning and ventilation in the Southern Ocean in response to anthropogenic forcing.
The importance of 'invisible' dissolved organic carbon along the land-ocean aquatic continuum
Authors: Felgate Stacey L. ,   Authors
Published: March 2022

Land-ocean dissolved organic carbon (DOC) fluxes are a significant and changing component of the global carbon cycle. The current paradigm assumes that these fluxes are dominated by chromophoric or ‘coloured’ material (cDOC). DOC is often characterised and quantified using optical tools which specifically target this fraction. However, multiple studies point towards a potentially sizeable non-coloured or optically ‘invisible’ DOC (iDOC) pool which is not covered by such characterisations. Only a handful of studies have directly investigated iDOC, and so its source, composition, behaviour, and geographic prevalence remain poorly understood.

Here we show that iDOC accounts for 21 % (0.23 Tg C yr-1) of annual riverine export in Great Britain (GB), with spatial variation in catchment-scale mean annual export depending upon forest cover and mean dairy cattle density. Using > 2,900 samples from across a range of geo-climatic settings across five continents we find a similar result: iDOC accounts for 26 % of the measured DOC flux in freshwaters. Our results indicate that iDOC is more prevalent in systems with a high degree of anthropogenic influence and/or a high residence time. 

We also show that estuarine DOC behaviour is driven by the contributions of cDOC and iDOC, at least within GB estuaries: cDOC almost universally exhibits conservative transport, whilst apparent non-conservative bulk DOC transport is typically caused by fluctuations in the iDOC fraction.

We conclude that iDOC is a globally significant fraction of the land-ocean carbon flux, the broad scale importance of which has been largely overlooked. This has fundamental implications for (1) our understanding of aquatic biogeochemistry and (2) the use and interpretation of optical parameters as they relate to DOC characterisation and quantification.

This work was primarily funded by the National Environment Research Council (NERC) through the SPITFIRE Doctoral Training Programme (grant number NE/L002531/1) and the Land Ocean Carbon Transfer Programme (LOCATE; grant number NE/N018087/1). 
Analogue modelling of subduction: yesterday, today and tomorrow.
Authors: Funiciello Francesca
Published: March 2022

The use of experimental tectonics (also known as analogue-, laboratory, or physical modelling) to study tectonic processes is not a novelty in Earth Science. Following Sir James Hall’s pioneer work (1815), many modellers squeezed, stretched, pushed and pulled a wide range of materials – e.g., sand, clay, oil, painters’ putties, gelatins, wax, paraffin, syrups, polymers – to unravel a wide range of tectonic processes to determine parameters controlling their geometry, kinematics and dynamics. However, only recently experimental analogue modelling has definitively transformed from a qualitative to a quantitative technique, thanks to appropriate scaling relationships, the improvement in the knowledge of the rheology of both natural and analogue materials and the use of high-resolution monitoring techniques to quantify morphology, kinematics, stress, strain and temperature.

Here, I specifically review the experimental work performed to study one of the most intriguing aspects of plate tectonics: the subduction process. Subduction provides the dominant engine for plate tectonics and mantle dynamics. Moreover, it has also societal importance playing a key role on hazard at short (i.e., earthquakes and mega-earthquakes, tsunami, effusive and explosive volcanic activities with impact on aviation safety) and long time scales (i.e., local and global climate change). Over the last decades, a noteworthy advance in the quality and density of global geological, geophysical and experimental data has allowed us to provide systematic quantitative analyses of global subduction zones and to speculate on their behaviour. These constraints have been integrated into a mechanical framework through modelling.

I will bring you to a journey through the past, the present and the future of analogue modelling and related efforts, results and perspectives for the study of the subduction process. It will be shown how analogue models, with their inherent 3D character and behaviour driven by simple and natural physical laws, contribute to successfully unravelling the subduction process, inspiring new ideas. Challenging ongoing perspectives of analogue models imply the possibility to compare time and space scales, allowing to merge, within the same model, both short- and long-term and shallow and deep processes.
Observation-based reconciliation of the Earth's Energy Imbalance budget constraint
Authors: Minière Audrey , von Schuckmann Karina , Monier Maeva , Le Traon Pierre-Yves , Sallée Jean-Baptiste
Published: March 2022

The Earth’s Energy Imbalance (EEI) represents the balance of heat fluxes between
the Earth and outer space in response to radiative forcings and associated climate feedbacks,
and as such is a key metric to understand and define global climate change. Recent
publications have shown that the EEI has doubled in the last two decades, which would have
major impacts on the different components of the Earth’s system. However, these results also
show inconsistencies in the quantification of this increase depending on the observing system
considered. In this study, we investigate two independent ways to estimate EEI from ocean
observations and from energy budget at the top of the atmosphere inferred from satellite. We
show that these two observing systems lead to consistent estimates of EEI variability and
amplitude over the period 2005-2019. Global Ocean Heat Content (GOHC) is derived from a
suite of ocean in situ temperature products, and is also compared to satellite estimate and to
ocean reanalysis estimate. We provide recommendations on how to achieve a consistent and
optimized observation-based comparison between estimates for the EEI budget constraint
approach from independent global climate observing system components and at different
time-scale ranging from interannual to decadal.
What can hydrologic signatures teach us about a multiyear drought?
Authors: Saft Margarita , Peel Murray , Fowler Keirnan , Peterson Tim
Published: March 2022

The internal dynamics of a catchment can be shifted by multiyear dry periods. While there is consensus that annual streamflow decreases for a given annual rainfall in the case of multiyear dry period significantly more than during isolated dry years (thus representing a shift in hydrologic response), the mechanism of this shift remains debated. As the hydrological shifts were investigated on an annual and, to a lesser extent, seasonal scale, little is known regarding what parts of the flow regime (e.g. high flows, low flows, recessions) are affected and how. An event-scale analysis using process-linked hydrologic metrics (or signatures) can reveal hidden patterns in catchment response to multiyear drought and shed light on the otherwise hidden hydrological processes. Additionally, understanding whether some parts of flow variability experienced a more pronounced impact from the drought may be important for the water management decision-making. Here we investigate long-term changes in catchment response on daily to sub-monthly timescales to aid both hydrological processes understanding and water management practice.

We calculate over 30 hydrologic signatures characterising different aspects of flow regime and hydrological processes before, during, and after a decade-long drought and compare the results.  The signatures are calculated with the Toolbox for Streamflow Signatures in Hydrology (TOSSH) which combines signature sets from several earlier studies. We use a well-known multiyear drought, the Millennium Drought (MD) in Australia as our case study. This drought spanned ~13 years (1997-2009) and affected over 1 million square kilometres of land including 156 semi-natural study catchments in Victoria.

Our results suggest that on average both high and low flows were affected in similar proportion while the shape (i.e. slope) of the flow duration curve was largely preserved. The tendency to generate less runoff for a given rainfall has been demonstrated in a range of signatures from event to total flow volumes and thus is independent of the timescale. When analysing signatures related to catchment storage, we observe that the decline continues post-drought. Baseflow index and recession signatures show some evidence of multiyear catchment storage buffering. There is also evidence of lower hydrologic connectivity in the hillslopes affecting the event runoff. However, there are marked differences in signature behaviour between different catchments reflecting the differences in catchment internal structure and dominant hydrologic processes.
Atmospheric response to reduced Antarctic sea ice drives ice sheet mass and energy flux anomalies
Authors: Trusel Luke , Kromer Jessica , Lenaerts Jan
Published: March 2022

The mass balance of the Antarctic ice sheet is intricately linked to the state of the atmosphere and ocean surrounding the continent. As a direct result, improving projections of future sea level change relies on understanding change in the Antarctic atmosphere and Southern Ocean, as well as the processes that couple these systems. Here, we explore the influence of sea ice cover on the overlying atmosphere and subsequently the energy and mass budgets of the adjacent Antarctic ice sheet. We investigate these processes using simulations of the Community Earth System Model 2 (CESM2) developed as part of the Polar Amplification Model Intercomparison Project (PAMIP). Specifically, we explore an ensemble of atmosphere-only time slice experiments where the sea ice cover is altered. Results highlight atmospheric warming in all seasons in response to sea ice loss, but particularly pronounced warming at the surface and during non-summer seasons. Sea ice reductions further drive positive anomalies in atmospheric moisture and liquid-bearing clouds, resulting in both enhanced precipitation and downward longwave radiative fluxes over the ice sheet, particularly in West Antarctica. We furthermore explore the impact of sea ice loss on primary modes of atmospheric variability, including the Amundsen Sea low and Southern Annular Mode. These results highlight the potential impact and importance of proper simulation of the Southern Ocean sea ice cover for determining the surface mass balance of the adjacent Antarctic ice sheet. Given that the current generation of coupled climate models struggle with representing observed sea ice dynamics, our results indicate this may likely contribute to uncertainties in the simulation of recent and future Antarctic ice sheet mass balance.