bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on coordination development schemes of mining and dumping engineering in steeper anticline region of an open-pit coal mine with nearly flat coal seam
Authors: Zhao Jingchang , Wang Xiangbo , Wang Dong , Liu Guangwei , Cao Bo
Published: September 2022

In this study, we present the coordination development schemes of mining and dumping engineering in steeper anticline region of an open-pit coal mine with nearly flat coal seam. Steeper anticlines in an open-pit coal mine with a nearly flat coal seam lead to drastic changes in local geological features and have many adverse effects on safe, economical, and efficient production. Based on an impact analysis of the anticline on the production quantity and quality of coal, release and utilization of the internal dumping space, layout of the haulage system and so on, the key technical solutions related to mining and dumping engineering coordination development in the steeper anticline region are discussed. Subsequently, taking the Antaibao Open-pit Coal Mine as a case study, based on the geological features of the steeper anticline region, two mining and dumping engineering coordination development schemes, the northern priority development scheme and the pseudo-longitudinal mining scheme, are proposed. Key technical parameters including the length and preceding distance of the priority development working-line, preceding distance and the horizontal advancing speed of the mining working line are determined. To compare the two proposed schemes in detail, the mining and dumping coordination development plans of the two proposed schemes during mining over the steeper anticline region are worked out, and some technical indices are computed. Using the six selected key indices, a multi-index comprehensive evaluation model based on CRITIC-TOPSIS is established to evaluate the two schemes. The evaluation results show that the northern priority development scheme is better than the pseudo-longitudinal mining scheme.

Article Highlights

The impact of steeper anticline on production of open-pit coal mine with nearly flat coal seam is analyzed, including: production quantity and quality of coal, release and utilization of internal dumping space, transportation distance and cost, etc.

According to the geological features of the anticline region, solutions for the technical issues are proposed, such as coal exposure, working-line layout and development, internal dump construction and development, haulage system layout, and the selective mining of coal.

Taking the Antaibao Open-pit Coal Mine as a case study, two mining and dumping engineering coordination development schemes are proposed. With the six selected key indices of the mining and dumping coordination development plans of the two proposed schemes during mining over the steeper anticline region, a multi-index comprehensive evaluation model of CRITIC-TOPSIS is established to evaluate the two proposed mining and dumping engineering coordination development schemes.
Mechanical behavior and microstructure evolution during high strain rate deformation of AA7075-T651
Authors: Dalai Biswajit , Moretti Marie Anna , Åkerström Paul , Esin Vladimir A. , Lindgren Lars-Erik
Published: September 2022

The current study presents the effects of strain and temperature on the mechanical response and microstructure evolution in AA7075-T651 at high strain rates. Compression tests have been performed at room temperature (RT), 200, 300 and 400 °C using a Split-Hopkinson pressure bar (SHPB) setup with strain rates ranging between 1400 and 5300 s−1. For deformation at RT, the flow stress increases with increase in strain rate. Whereas deformation at elevated temperatures show a non-monotonous behavior of the flow stress with respect to the strain rate. This trait is attributed to the pronounced effects from the adiabatic shear bands (ASBs); namely, distorted shear bands (DSBs) and transformed shear bands (TSBs); and cracks resulting from the plastic deformation instability during hot deformation. The sequence of microstructure evolution is: inhomogeneity in the initial microstructure – DSB – TSB – crack –fracture. The feasibility of formation and growth of ASBs and cracks increases with increase in strain and temperature, neglecting any significant effect from the strain rate. During the compression tests, temperature of the material rises due to adiabatic heating. Considering a certain strain developed in the material, this adiabatic temperature rise decreases as the deformation temperature is increased. Furthermore, during individual deformation processes, the temperature rise increases with increasing strain. The adiabatic temperature leading to the formation of TSB is approximated to be 0.7 times of the melting temperature of the alloy. These results from the current study are to be used in developing a physics-based material model for the alloy.

Article Highlights

At elevated temperatures, compression with Split-Hopkinson bars produce two types of shear bands and cracks.

Evolution of shear bands and cracks is promoted by increase in strain and temperature irrespective of strain rate.

Adiabatic temperature approximating to 70% of the melting point forms refined grain structure of transformed band.
Male Nudity in the Greek Iron Age
Authors: Murray Sarah
Published: September 2022

Why did the male nude come to occupy such an important place in ancient Greek culture? Despite extended debate, the answer to this question remains obscure. In this book, Sarah Murray demonstrates that evidence from the Early Iron Age Aegean has much to add to the discussion. Her research shows that aesthetics and practices involving male nudity in the Aegean had a complicated origin in prehistory. Murray offers a close analysis of the earliest male nudes from the late Bronze and Early Iron Ages, which mostly take the form of small bronze votive figurines deposited in rural sanctuaries. Datable to the end of the second millennium BCE, these figurines, she argues, enlighten the ritual and material contexts in which nude athletics originated, complicating the rationalizing accounts present in the earliest textual evidence for such practices. Murray's book breaks new ground by reconstructing a scenario for the ritual and ideological origins of nudity in Greek art and culture.
Wave patterns of stationary gravity–capillary waves from a moving obstacle in a magnetic fluid
Authors: Krakov M.S. , Khokhryakova C.A. , Kolesnichenko E.V.
Published: September 2022

The influence of a magnetic field on the pattern of stationary waves formed on the surface of a magnetic fluid (ferrofluid) when an obstacle moves has been studied both theoretically and experimentally. It is found that a vertical magnetic field narrows the cone of stationary waves and increases their amplitude. In the wake region, the peaks of the Rosensweig instability appear in a magnetic field that is smaller than the critical field that determines this instability occurrence. A horizontal magnetic field parallel to the obstacle velocity expands the cone of waves but reduces their amplitude up to the suppression of stationary waves. A horizontal field perpendicular to the obstacle velocity also expands the cone of waves and stabilizes their amplitude.
Exploring issues in categorisation of higher music education courses through FOI surveys of gender demographics in UK higher education institutions
Authors: Tatlow Stephen
Published: September 2022

A common conclusion drawn from publicly available Higher Education Statistics Agency (HESA) data releases is that Higher Music Education (HME) courses have a predominantly male population. However, HESA data has key issues when examining HME courses: which courses are reported as ‘music’ courses to HESA; how do universities decide which courses are ‘music’ courses; how many different topics are contained within the umbrella of ‘music’ courses? To address questions of gender representation in HME, universities in the UK were approached with Freedom of Information Act requests for the gender demographics of student populations on “music-related” courses. Information was gained on 3456 courses populations between 2014 and 2020, which was categorised by the subject of study. Six core undergraduate topics were identified: generic music degrees (female bias), degrees combining music and technology (male bias), degrees combining music and business (no gender bias), degrees on popular music (male bias), degrees combining music and theatre (female bias) and major conservatoire courses (no gender bias). No area was accurately represented by HESA data, and gender representation varied significantly between areas. These findings have implications for discussions of gender representation in HME across the UK.
Uniqueness of the Gibbs measure for the 4-state anti-ferromagnetic Potts model on the regular tree
Authors: de Boer David , Buys Pjotr , Regts Guus
Published: September 2022

We show that the
$4$
-state anti-ferromagnetic Potts model with interaction parameter
$w\in (0,1)$
on the infinite
$(d+1)$
-regular tree has a unique Gibbs measure if
$w\geq 1-\dfrac{4}{d+1_{_{\;}}}$
for all
$d\geq 4$
. This is tight since it is known that there are multiple Gibbs measures when
$0\leq w\lt 1-\dfrac{4}{d+1}$
and
$d\geq 4$
. We moreover give a new proof of the uniqueness of the Gibbs measure for the
$3$
-state Potts model on the
$(d+1)$
-regular tree for
$w\geq 1-\dfrac{3}{d+1}$
when
$d\geq 3$
and for
$w\in (0,1)$
when
$d=2$
.
Leveraging machine translation for cross-lingual fine-grained cyberbullying classification amongst pre-adolescents
Authors: Verma Kanishk , Popović Maja , Poulis Alexandros , Cherkasova Yelena , Ó hÓbáin Cathal , Mazzone Angela , Milosevic Tijana , Davis Brian
Published: September 2022

Cyberbullying is the wilful and repeated infliction of harm on an individual using the Internet and digital technologies. Similar to face-to-face bullying, cyberbullying can be captured formally using the Routine Activities Model (RAM) whereby the potential victim and bully are brought into proximity of one another via the interaction on online social networking (OSN) platforms. Although the impact of the COVID-19 (SARS-CoV-2) restrictions on the online presence of minors has yet to be fully grasped, studies have reported that 44% of pre-adolescents have encountered more cyberbullying incidents during the COVID-19 lockdown. Transparency reports shared by OSN companies indicate an increased take-downs of cyberbullying-related comments, posts or content by artificially intelligen moderation tools. However, in order to efficiently and effectively detect or identify whether a social media post or comment qualifies as cyberbullying, there are a number factors based on the RAM, which must be taken into account, which includes the identification of cyberbullying roles and forms. This demands the acquisition of large amounts of fine-grained annotated data which is costly and ethically challenging to produce. In addition where fine-grained datasets do exist they may be unavailable in the target language. Manual translation is costly and expensive, however, state-of-the-art neural machine translation offers a workaround. This study presents a first of its kind experiment in leveraging machine translation to automatically translate a unique pre-adolescent cyberbullying gold standard dataset in Italian with fine-grained annotations into English for training and testing a native binary classifier for pre-adolescent cyberbullying. In addition to contributing high-quality English reference translation of the source gold standard, our experiments indicate that the performance of our target binary classifier when trained on machine-translated English output is on par with the source (Italian) classifier.
On the Reliability of Global Seasonal Forecasts: Sensitivity to Ensemble Size, Hindcast Length and Region Definition
Authors: Manzanas R. , Torralba V. , Lledó Ll. , Bretonnière P. A.
Published: September 2022

One of the key quality aspects in a probabilistic prediction is its reliability. However, this property is difficult to estimate in the case of seasonal forecasts due to the limited size of most of the hindcasts that are available nowadays. To shed light on this issue, this work presents a detailed analysis of how the ensemble size, the hindcast length and the number of points pooled together within a particular region affect the resulting reliability estimates. To do so, we build on 42 land reference regions recently defined for the IPCC‐AR6 and assess the reliability of global seasonal forecasts of temperature and precipitation from the European Center for Medium Weather Forecasts SEAS5 prediction system, which is compared against its predecessor, System4. Our results indicate that whereas longer hindcasts and larger ensembles lead to increased reliability estimates, the number of points that are pooled together within a homogeneous climate region is much less relevant.
Characteristic Analysis of Relationship Between Precipitation and Turbulence in the Troposphere and Lower Stratosphere Over Tropical Western Pacific
Authors: Qin Z. , Sheng Z. , He Y. , Zhao X. , Tian T.
Published: September 2022

This study aims to analyze the distribution characteristics of turbulence in the western Pacific tropical region and determine the correlation between turbulence and precipitation. The obtained results show that due to the combined action of large wind shear and thermal convection, the near‐surface layer is conducive to the generation of large‐scale turbulence, and the maximum Thorpe scale can reach more than 600 m. A strong mixing zone of turbulence is generated in 10–16 km, with the monthly average occurrence rate of turbulence being about 40% and the maximum value reaching 50%. There is less turbulence in lower stratosphere due to the rapidly increased atmosphere static stability. All Thorpe scales in stratosphere are less than 100 m. The response of turbulence to precipitation in the upper troposphere is strongly affected by clouds. At the altitude in the clouds, the enhancement of precipitation has a negative relationship with turbulence. The average value of and turbulence layer thickness on rainy days are both smaller than those when the precipitation weakened. At the altitude above the clouds, the enhancement of precipitation has a slight promotion effect on the turbulence, especially for the emergence of large‐scale turbulence. When the precipitation intensifies, the amount of turbulence with greater than 150 m accounts for 6.7% of the total, while the proportion is only 2.6% on less rainy days.
Teleconnection Patterns of Different El Niño Types Revealed by Climate Network Curvature
Authors: Strnad Felix M. , Schlör Jakob , Fröhlich Christian , Goswami Bedartha
Published: September 2022

The diversity of El Niño events is commonly described by two distinct flavors, the Eastern Pacific (EP) and Central Pacific (CP) type. While the remote impacts, that is, teleconnections, of EP and CP events have been studied for different regions individually, a global picture of their structure is still lacking. Here, we use Forman‐Ricci curvature applied on climate networks constructed from surface air temperature data to distinguish regional links from teleconnections. Our results confirm that both El Niño types influence the teleconnection patterns, however, with different spatial manifestations. Our analysis suggests that EP El Niños alter the general circulation which changes the teleconnection structure to primarily tropical teleconnections. In contrast, the teleconnection pattern of CP El Niños show only subtle changes to normal conditions. Moreover, this work identifies the dynamics of the Eastern Pacific as a proxy for the remote impact of both El Niño types.
Drifter Observations Reveal Intense Vertical Velocity in a Surface Ocean Front
Authors: Tarry Daniel R. , Ruiz Simón , Johnston T. M. Shaun , Poulain Pierre‐Marie , Özgökmen Tamay , Centurioni Luca R. , Berta Maristella , Esposito Giovanni , Farrar J. Thomas , Mahadevan Amala , Pascual Ananda
Published: September 2022

Measuring vertical motions represent a challenge as they are typically 3–4 orders of magnitude smaller than the horizontal velocities. Here, we show that surface vertical velocities are intensified at submesoscales and are dominated by high frequency variability. We use drifter observations to calculate divergence and vertical velocities in the upper 15 m of the water column at two different horizontal scales. The drifters, deployed at the edge of a mesoscale eddy in the Alboran Sea, show an area of strong convergence ((f)) associated with vertical velocities of −100 m day−1. This study shows that a multilayered‐drifter array can be an effective tool for estimating vertical velocity near the ocean surface.
Reduction in Near‐Surface Wind Speeds With Increasing CO2 May Worsen Winter Air Quality in the Indo‐Gangetic Plain
Authors: Paulot Fabien , Naik Vaishali , W. Horowitz Larry
Published: September 2022

We analyze the relationship between fine particulate matter (PM2.5) and meteorology in winter in the Indo‐Gangetic Plain (IGP). We find that the concentration of PM2.5 exhibits similar increase with decreasing surface wind speed in 15 out of 18 cities considered. Using this observed relationship, we estimate that the reduction of surface wind speed with increasing CO2 simulated by models participating in the Coupled Model Intercomparison Project Phase 6 will result in higher average wintertime PM2.5 concentrations (1% per degree K of global warming) and more frequent high‐pollution events. This observation‐based estimate is qualitatively consistent with the simulated response of black carbon to global warming inferred from the AerChemMIP ssp370SST and ssp370pdSST experiments. We hypothesize that a reduction in the frequency and intensity of western disturbances with increasing CO2 may contribute to the reduction in the surface wind in the IGP.
Satellite Detection of a Massive Phytoplankton Bloom Following the 2022 Submarine Eruption of the Hunga Tonga‐Hunga Haʻapai Volcano
Authors: Barone B. , Letelier R. M. , Rubin K. H. , Karl D. M.
Published: September 2022

The largest submarine volcanic eruption of this century led to a dramatic phytoplankton bloom north of the island of Tongatapu, in the Kingdom of Tonga. In the absence of shipboard observations, we reconstructed the dynamics of this event by using a suite of satellite observations. Two independent bio‐optical approaches confirmed that the phytoplankton bloom was a robust observation and not an optical artifact due to volcanogenic material. Furthermore, the timing, size, and position of the phytoplankton bloom suggest that plankton growth was primarily stimulated by nutrients released from volcanic ash rather than by nutrients upwelled through submarine volcanic activity. The appearance of a large region with high chlorophyll a concentrations <48 hr after the largest eruptive phase indicates a fast ecosystem response to nutrient fertilization. However, net phytoplankton growth probably initiated before the main eruption, when weaker volcanism had already fertilized the ocean.
Melting Experiments on Fe‐O‐H and Fe‐H: Evidence for Eutectic Melting in Fe‐FeH and Implications for Hydrogen in the Core
Authors: Oka Kenta , Ikuta Nagi , Tagawa Shoh , Hirose Kei , Ohishi Yasuo
Published: September 2022

We examined liquidus phase relations in Fe‐O ± H at ∼40 and ∼150 GPa, and in Fe‐H at 45 GPa. While it has been speculated that Fe and FeH form continuous solid solution to core pressures, our experiment on Fe‐H showed that FeH0.20 forms with the hcp structure, different from fcc for stoichiometric FeH, and melts at temperature lower than that for FeH, suggesting eutectic melting between Fe and FeH. It is consistent with the liquidus phase diagram in Fe‐O‐H, which implies the Fe‐FeH binary eutectic liquid composition of FeH0.42 at ∼40 GPa. These experiments also demonstrated the partition coefficient of H between solid Fe and liquid, DH (solid/liquid) = 0.77–0.89. We estimated the outer core liquid composition based on the liquidus phase relations, solid‐liquid partitioning, and outer/inner core densities and velocities, indicating that O and either H or Si are important core light elements.
Nitrogen Isotope Evidence for Changing Arctic Ocean Ventilation Regimes During the Cenozoic
Authors: Knies Jochen
Published: September 2022

In this work, I report on the coupling of dinitrogen (N2) fixation and denitrification in oxygen‐deficient waters of the Arctic Ocean during the Paleogene. This coupling fertilized marine phytoplankton growth and favored organic carbon burial. Reduced vertical mixing due to salinity stratification in a tectonically closed oceanic basin created conditions favorable for N2‐fixation by phytoplankton harboring diazotrophic bacterial symbionts. A positive shift of 5‰ in the δ15N record indicates a change in the main source of biologically available nitrogen due to rapidly changing nutrient availability. I interpret this shift as a switch to Atlantic‐sourced nitrate as the main nitrogen source owing to the opening of the Arctic‐Atlantic gateway to the northern North Atlantic. While the timing of the opening is still disputed among the available Arctic records, I use evidence from the northern North Atlantic to argue that the Arctic Ocean has been fully ventilated since the early Neogene.
Evolving Interior Mixing Regimes in a Tidal River Plume
Authors: Spicer Preston , Huguenard Kimberly , Cole Kelly L. , MacDonald Daniel G. , Whitney Michael M.
Published: September 2022

Microstructure profiling was utilized to estimate vertical mixing (via vertical turbulent buoyancy flux) during a tidal pulse in the interior Merrimack River plume in calm winds. Multiple stratified shear mixing regimes appear and evolve with time. Initially the plume acts as a nearfield jet, with mixing in the plume (plume layer mixing) and over the plume‐ambient interface (nearfield interfacial mixing). As the plume grows, interfacial mixing is suppressed offshore of the nearfield as currents slow, diminishing turbulent exchange between plume and shelf. At the end of ebb, ambient tidal currents reverse direction below plume, initiating another mode of internal, interfacial mixing (coined here as tidal interfacial mixing), allowing exchange between plume and ambient waters offshore. This work highlights previously unreported tidally modulated mixing within the near and midfield of a river plume.
The Value of Probabilistic Prediction for Lightning Ignited Fires
Authors: Di Giuseppe F.
Published: September 2022

In 2021, the availability of a physical model for lightning density prediction at ECMWF led to the development of data driven models to identify episodes conducive of fires. The machine‐learning classifiers worked remarkably well reaching an overall accuracy up to 78%. Still, errors in the lightning forecast substantially reduce the prediction skill. An ensemble of predictions is used to take into account the stochastic nature of the forecast errors. An assessment of the predictive skill in terms of probabilities is performed and is bench‐marked against the deterministic outcome provided by a single deterministic realization. The probabilistic prediction is more skillful than the deterministic one and there is an optimal probability threshold that allows to maximize the correlation between prediction and observed ignitions. Probabilistic forecast also brings the best value for money when a cost‐loss analysis is performed, and a potential economic value is attributed to the forecast.
Hexagonal Prisms Form in Water‐Ice Clouds on Mars, Producing Halo Displays Seen by Perseverance Rover
Authors: Lemmon M. T. , Toledo D. , Apestigue V. , Arruego I. , Wolff M. J. , Patel P. , Guzewich S. , Colaprete A. , Vicente‐Retortillo Á. , Tamppari L. , Montmessin F. , de la Torre Juarez M. , Maki J. , McConnochie T. , Brown A. , Bell J. F.
Published: September 2022

Observations by several cameras on the Perseverance rover showed a 22° scattering halo around the Sun over several hours during northern midsummer (solar longitude 142°). Such a halo has not previously been seen beyond Earth. The halo occurred during the aphelion cloud belt season and the cloudiest time yet observed from the Perseverance site. The halo required crystalline water‐ice cloud particles in the form of hexagonal columns large enough for refraction to be significant, at least 11 μm in diameter and length. From a possible 40–50 km altitude, and over the 3.3 hr duration of the halo, particles could have fallen 3–12 km, causing downward transport of water and dust. Halo‐forming clouds are likely rare due to the high supersaturation of water that is required but may be more common in northern subtropical regions during northern midsummer.
Ionic Charge Emission Into Fog From a Remotely Piloted Aircraft
Authors: Harrison R. Giles , Nicoll Keri A. , Marlton Graeme J. , Tilley Douglas J. , Iravani Pejman
Published: September 2022

Charge influences the properties of liquid droplets, such as evaporation rates, hydrodynamic stability, and sticking probabilities. Modifying droplet charge therefore provides a possible method of influencing fogs or clouds. An instrumented, remotely piloted aircraft has been equipped with positive and negative corona emitters to cause droplet charging. With the aircraft circling at 20 m altitude, effects of ion release were compared in clear air and natural fog. In clear air, the surface atmospheric electrical field changed whenever the emitters were activated, but without significant differences in the short‐wave radiation as the aircraft passed over previously ionized air. In fog, radiation fluctuations showed a Gaussian distribution before either emitter operated or when both emitters were operating, but with different distributions during unipolar ion emission. Introducing unipolar ions led to a maximum change in fog reflectivity of ∼2%, about 25 s later.
Emirates Mars Ultraviolet Spectrometer's (EMUS) Observation of Argon in the Martian Thermosphere
Authors: Lootah Fatma Hussain , Deighan Justin , Fillingim Matthew , Jain Sonal , Evans J. Scott , Al Matroushi Hessa , Chaffin Michael , Holsclaw Gregory , Lillis Robert , Al Mazmi Hour , Correira John , England Scott
Published: September 2022

The Emirates Mars Ultraviolet Spectrometer (EMUS) is a far ultraviolet spectrometer on‐board the Emirates Mars Mission's (EMM) which arrived at Mars on 9 February 2021. EMUS is designed to observe key neutral species in the Martian thermosphere (100–200 km) and exosphere (≥200 km). EMUS has observed two neutral argon (Ar) emission lines, Ar I 104.8 nm and Ar I 106.6 nm, in the thermosphere. Our interest in these emissions stem from argon's non‐reactiveness, making it a tracer for transport between the upper and lower atmosphere. We report average argon disk brightness measured by EMUS and compare them to measurements from Earth orbiting observatories. For the first time, this work investigates the variability of Ar I 106.6 nm brightness due to emission angles, solar zenith angles, solar longitudes, local times and latitudes. To contrast the behavior of inert argon we compare these results with the photochemically reactive oxygen 135.6 nm.
Relativistic Electron Precipitation by EMIC Waves: Importance of Nonlinear Resonant Effects
Authors: Grach Veronika S. , Artemyev Anton V. , Demekhov Andrei G. , Zhang Xiao‐Jia , Bortnik Jacob , Angelopoulos Vassilis , Nakamura Rumi , Tsai Ethan , Wilkins Colin , Roberts Owen W.
Published: September 2022

Relativistic electron losses in Earth's radiation belts are usually attributed to electron resonant scattering by electromagnetic waves. One of the most important wave modes for such scattering is the electromagnetic ion cyclotron (EMIC) mode. Within the quasi‐linear diffusion framework, the cyclotron resonance of relativistic electrons with EMIC waves results in very fast electron precipitation to the atmosphere. However, wave intensities often exceed the threshold for nonlinear resonant interaction, and such intense EMIC waves have been shown to transport electrons away from the loss cone due to the force bunching effect. In this study we investigate if this transport can block electron precipitation. We combine test particle simulations, low‐altitude observations of EMIC‐driven electron precipitation by the Electron Losses and Fields Investigations mission, and ground‐based EMIC observations. Comparing simulations and observations, we show that, despite the low pitch‐angle electrons being transported away from the loss cone, the scattering at higher pitch angles results in the loss cone filling and electron precipitation.
Volcano Monitoring With Magnetic Measurements: A Simulation of Eruptions at Axial Seamount, Kīlauea, Bárðarbunga, and Mount Saint Helens
Authors: Biasi Joseph , Tivey Maurice , Fluegel Bailey
Published: September 2022

Monitoring of active volcanic systems is a challenging task due in part to the trade‐offs between collection of high‐quality data from multiple techniques and the high costs of acquiring such data. Here we show that magnetic data can be used to monitor volcanoes by producing similar data to gravimetric techniques at significantly lower cost. The premise of this technique is that magma and wall rock above the Curie temperature are magnetically “transparent,” but not stationary within the crust. Subsurface movements of magma can affect the crustal magnetic field measured at the surface. We construct highly simplified magnetic models of four volcanic systems: Mount Saint Helens (1980), Axial Seamount (2015–2020), Kīlauea (2018), and Bárðarbunga (2014). In all cases, observed or inferred changes to the magmatic system would have been detectable by modern magnetometers. Magnetic monitoring could become common practice at many volcanoes, particularly in developing nations with high volcanic risk.
The Magnetization of an Underwater Caldera: A Time‐Lapse Magnetic Anomaly Study of Axial Seamount
Authors: Fluegel Bailey , Tivey Maurice , Biasi Joseph , Chadwick William W. , Nooner Scott L.
Published: September 2022

Axial Seamount in the northeast Pacific erupted in 2015, 2011, and 1998. Although monitored by the Regional Cabled Array of the Ocean Observatory Initiative, few magnetic surveys have been conducted over the region. This study uses high‐resolution magnetic data over the seamount collected by autonomous underwater vehicle Sentry during three years (2015, 2017, and 2020). The goal is to investigate whether there are temporal changes in the near‐surface magnetic field observable over the time scale of one volcanic cycle. We compare magnetic maps from repeated tracklines from each year. We find maps of the yearly difference in magnetization show coherent patterns that are not random. The central region of the caldera has become more magnetic during recent years, suggesting cooling of the surficial lava flows since 2015. Sentry data are more sensitive to shallow crustal structure compared to sea surface data which show longer wavelength anomalies extending deeper into the crust.
Significant Effective Radiative Forcing of Stratospheric Wildfire Smoke
Authors: Liu Cheng‐Cheng , Portmann Robert W. , Liu Shang , Rosenlof Karen H. , Peng Yifeng , Yu Pengfei
Published: September 2022

The radiative forcing (RF) of volcanic sulfate is well quantified. However, the RF of pyrocumulonimbus (pyroCb) smoke with absorbing carbonaceous aerosols has not been considered in climate assessment reports. With the Community Earth System Model, we studied two record‐breaking wildfire events, the 2017 Pacific Northwest Event (PNE) and the 2019–2020 Australian New Year event (ANY), that perturbed stratospheric chemistry and the earth's radiation budget. We calculated a global annual‐mean effective RF (ERF) of −0.04 ± 0.02 and −0.17 ± 0.02 W/m2 at the top of the atmosphere (TOA) for PNE and ANY, respectively. The complexity of longwave RF led to an uncertainty of about 50% in the ERF at the TOA among climate models. We found that modeled ERF from wildfire smoke was 70%–270% more negative than the ERF of mass‐equivalent sulfate aerosol, highlighting its important role in the climate radiative budget.
BepiColombo Mio Observations of Low‐Energy Ions During the First Mercury Flyby: Initial Results
Authors: Harada Yuki , Aizawa Sae , Saito Yoshifumi , André Nicolas , Persson Moa , Delcourt Dominique , Hadid Lina Z. , Fraenz Markus , Yokota Shoichiro , Fedorov Andréi , Miyake Wataru , Penou Emmanuel , Barthe Alain , Sauvaud Jean‐André , Katra Bruno , Matsuda Shoya , Murakami Go
Published: September 2022

We present initial results of low‐energy ion observations from BepiColombo's first Mercury flyby. Unprecedentedly high time resolution measurements of low energy ions at Mercury by BepiColombo Mio reveal rapid (a few seconds) and large (1–2 orders of magnitude) fluctuations of ion flux around the magnetopause and within the magnetosphere. Around the magnetic equator in the pre‐midnight magnetotail, Mio observed plasma sheet ions consistent with previous observations. In the midnight magnetotail near the closest approach, Mio observed the co‐existence of high‐energy (∼keV/q) and low‐energy (<∼300 eV/q) ion components. The low‐energy component is inferred to be cold with a temperature well below 100 eV and have a major contribution to the total density as opposed to previously reported cold tenuous ions. Future observations by Mio will provide insights into the sources, transport, and acceleration of the newly identified ion components.
Hydrogen Relative Permeability Hysteresis in Underground Storage
Authors: Lysyy Maksim , Føyen Tore , Johannesen Else Birkeland , Fernø Martin , Ersland Geir
Published: September 2022

Implementation of the hydrogen economy for emission reduction will require storage facilities, and underground hydrogen storage (UHS) in porous media offers a readily available large‐scale option. Lack of studies on multiphase hydrogen flow in porous media is one of the several barriers for accurate predictions of UHS. This paper reports, for the first time, measurements of hysteresis in hydrogen‐water relative permeability in a sandstone core under shallow storage conditions. We use the steady state technique to measure primary drainage, imbibition and secondary drainage relative permeabilities, and extend laboratory measurements with numerical history matching and capillary pressure measurements to cover the whole mobile saturation range. We observe that gas and water relative permeabilities show strong hysteresis, and nitrogen as substitute for hydrogen in laboratory assessments should be used with care. Our results serve as calibrated input to field scale numerical modeling of hydrogen injection and withdrawal processes during porous media UHS.
Day‐to‐Day Variability of the Semidiurnal Tide in the F‐Region Ionosphere During the January 2021 SSW From COSMIC‐2 and ICON
Authors: Oberheide J.
Published: September 2022

The semidiurnal tidal spectrum in the F‐region ionosphere obtained from hourly COSMIC‐2 Global Ionospheric Specification (GIS) data assimilation is greatly (>50%) enhanced during the January 2021 Sudden Stratospheric Warming (SSW). Moreover, the semidiurnal migrating tidal response in topside electron densities closely follows the day‐to‐day changes of the 10 hPa, 60°N zonal wind from MERRA‐2 during the SSW. The response is similar in the northern and southern crests of the Equatorial Ionization Anomaly (EIA) but persists toward higher magnetic latitudes and the EIA trough. A slight phase shift toward earlier local times is consistent with theoretical expectations of an E‐region dynamo driving and agrees with semidiurnal tidal diagnostics of MIGHTI/ICON zonal winds at 105 km. COSMIC‐2 GIS are the first data set to resolve the tidal weather of the ionosphere on a day‐to‐day basis and, therefore, provide a new perspective on space weather variability driven by lower and middle atmosphere dynamics.
Hadley Cell Edge Modulates the Role of Ekman Heat Flux in a Future Climate
Authors: Hasan Mahdi , Larson Sarah , McMonigal Kay
Published: September 2022

In a future climate, the Hadley cell and associated trade easterlies are projected to expand poleward. This projected change in the atmospheric circulation is expected to impact the ocean through changes in the mean sea surface temperature (SST). We also expect implications for the large‐scale SST variability, because near‐surface wind is directly related to two drivers of the SST, that is, turbulent heat flux and anomalous wind‐driven Ekman heat flux. Previous studies show that in the subtropics, anomalous turbulent and Ekman heat fluxes oppose each other, acting to reduce SST variability, whereas, in the midlatitudes, they reinforce each other and enhance SST variability. Through analysis of reanalysis products and Coupled Model Intercomparison Project simulations, we find that the subtropical regions where the fluxes oppose each other are projected to expand poleward in a future climate, following the poleward expansion of the Hadley cell, with potential implications for the amplitude of subtropical SST variability.
Droughts, Pluvials, and Wet Season Timing Across the Chao Phraya River Basin: A 254‐Year Monthly Reconstruction From Tree Ring Widths and δ18O
Authors: Nguyen Hung T. T. , Galelli Stefano , Xu Chenxi , Buckley Brendan M.
Published: September 2022

Water system operations require subannual streamflow data—e.g., monthly or weekly—that are not readily achievable with conventional streamflow reconstructions from annual tree rings. This mismatch is particularly relevant to highly seasonal rivers such as Thailand's Chao Phraya. Here, we combine tree ring width and stable oxygen isotope ratios (δ18O) from Southeast Asia to produce 254‐year, monthly‐resolved reconstructions for all four major tributaries of the Chao Phraya. From the reconstructions, we derive subannual streamflow indices to examine past hydrological droughts and pluvials, and find coherence and heterogeneity in their histories. The monthly resolution reveals the spatiotemporal variability in wet season timing, caused by interactions between early summer typhoons, monsoon rains, catchment location, and topography. Monthly‐resolved reconstructions, like the ones presented here, not only broaden our understanding of past hydroclimatic variability, but also provide data that are functional to water management and climate‐risk analyses, a significant improvement over annual reconstructions.
Auroral Spiral Structure Formation Through Magnetic Reconnection in the Auroral Acceleration Region
Authors: Huang Kai , Liu Yi‐Hsin , Lu Quanming , Hu Zejun , Lynch Kristina A. , Hesse Michael , Vaivads Andris , Yang Huigen
Published: September 2022

Auroral spiral is one of the auroral vortex structures. Here, we propose a model to explain the formation of auroral spiral structure based on three‐dimensional particle‐in‐cell simulations. In our model, an auroral arc develops through precipitations of electrons accelerated during magnetic reconnection in the auroral acceleration region. The arc morphology at low altitudes can be modified by electron‐scale magnetic flux ropes, which are generated through secondary oblique tearing modes in the intensified current sheet along one particular branch of the primary reconnection separatrices. The resulting vortex structures agree well with high‐resolution observations of auroral spirals. We find that the rotational sense of these spirals is determined by electron kinetic processes and controlled by the guide field direction. Our study further suggests that when the field‐aligned length of the auroral acceleration region is shorter than a critical length, these auroral spiral structures will not form.
Evolution of Droplet Size Distributions During the Transition of an Ultraclean Stratocumulus Cloud System to Open Cell Structure: An LES Investigation Using Lagrangian Microphysics
Authors: Chandrakar Kamal Kant , Morrison Hugh , Witte Mikael
Published: September 2022

A state‐of‐the‐art Lagrangian microphysics scheme is used in a large‐eddy simulation to investigate the stratocumulus transition from closed to open cell structure. Processes controlling precipitation development, which is a key to the transition, are analyzed by leveraging unique benefits of Lagrangian microphysics, particularly the ability to track computational drops in the flow. Sufficient time is needed for coalescence growth of cloud drops to drizzle within the updraft‐downdraft cycle of large eddies. This favors broad drop size distributions (DSDs) and drizzle growth in downdrafts, where drops are typically much older than in updrafts. During the closed cell stage, mean cloud drop radius is too small, and the DSDs are too narrow, so that the timescale for coalescence is much longer than the large eddy turnover time and drizzle growth is limited. The closed‐to‐open cell transition occurs when these timescales become comparable and the precipitation flux increases sharply.
Metabolic flux between organs measured by arteriovenous metabolite gradients
Authors: Bae Hosung , Lam Katie , Jang Cholsoon
Published: September 2022

Mammalian organs convert dietary nutrients into circulating metabolites and share them to maintain whole-body metabolic homeostasis. While the concentrations of circulating metabolites have been frequently measured in a variety of pathophysiological conditions, the exchange flux of circulating metabolites between organs is not easily measurable due to technical difficulties. Isotope tracing is useful for measuring such fluxes for a metabolite of interest, but the shuffling of isotopic atoms between metabolites requires mathematical modeling. Arteriovenous metabolite gradient measurements can complement isotope tracing to infer organ-specific net fluxes of many metabolites simultaneously. Here, we review the historical development of arteriovenous measurements and discuss their advantages and limitations with key example studies that have revealed metabolite exchange flux between organs in diverse pathophysiological contexts.
Broadband 1-GHz mid-infrared frequency comb
Authors: Hoghooghi Nazanin , Xing Sida , Chang Peter , Lesko Daniel , Lind Alexander , Rieker Greg , Diddams Scott
Published: September 2022

Mid-infrared (MIR) spectrometers are invaluable tools for molecular fingerprinting and hyper-spectral imaging. Among the available spectroscopic approaches, GHz MIR dual-comb absorption spectrometers have the potential to simultaneously combine the high-speed, high spectral resolution, and broad optical bandwidth needed to accurately study complex, transient events in chemistry, combustion, and microscopy. However, such a spectrometer has not yet been demonstrated due to the lack of GHz MIR frequency combs with broad and full spectral coverage. Here, we introduce the first broadband MIR frequency comb laser platform at 1 GHz repetition rate that achieves spectral coverage from 3 to 13 µm. This frequency comb is based on a commercially available 1.56 µm mode-locked laser, robust all-fiber Er amplifiers and intra-pulse difference frequency generation (IP-DFG) of few-cycle pulses in χ(2) nonlinear crystals. When used in a dual comb spectroscopy (DCS) configuration, this source will simultaneously enable measurements with μs time resolution, 1 GHz (0.03 cm−1) spectral point spacing and a full bandwidth of >5 THz (>166 cm−1) anywhere within the MIR atmospheric windows. This represents a unique spectroscopic resource for characterizing fast and non-repetitive events that are currently inaccessible with other sources.
Photo-induced macro/mesoscopic scale ion displacement in mixed-halide perovskites: ring structures and ionic plasma oscillations
Authors: Sun Xiaoxiao , Zhang Yong , Ge Weikun
Published: September 2022

Contrary to the common belief that the light-induced halide ion segregation in a mixed halide alloy occurs within the illuminated area, we find that the Br ions released by light are expelled from the illuminated area, which generates a macro/mesoscopic size anion ring surrounding the illuminated area, exhibiting a photoluminescence ring. This intriguing phenomenon can be explained as resulting from two counter-balancing effects: the outward diffusion of the light-induced free Br ions and the Coulombic force between the anion deficit and surplus region. Right after removing the illumination, the macro/mesoscopic scale ion displacement results in a built-in voltage of about 0.4 V between the ring and the center. Then, the displaced anions return to the illuminated area, and the restoring force leads to a damped ultra-low-frequency oscillatory ion motion, with a period of about 20–30 h and lasting over 100 h. This finding may be the first observation of an ionic plasma oscillation in solids. Our understanding and controlling the “ion segregation” demonstrate that it is possible to turn this commonly viewed “adverse phenomenon” into novel electronic applications, such as ionic patterning, self-destructive memory, and energy storage.
Galectin-3 critically mediates the hepatoprotection conferred by M2-like macrophages in ACLF by inhibiting pyroptosis but not necroptosis signalling
Authors: Bai Li , Lu Wang , Tang Shan , Tang Huixin , Xu Manman , Liang Chen , Zheng Sujun , Liu Shuang , Kong Ming , Duan Zhongping , Chen Yu
Published: September 2022

We previously documented that M2-like macrophages exert a hepatoprotective effect in acute-on-chronic liver failure (ACLF) by inhibiting necroptosis signalling. Nevertheless, the molecular mechanism behind this hepatoprotection still needs to be further dissected. Galectin-3 (GAL3) has been reported to be critically involved in the pathogenesis of multiple liver diseases, whereas the potential role of GAL3 in ACLF remains to be explored. Herein, we hypothesised that GAL3 plays a pivotal role in the hepatoprotection conferred by M2-like macrophages in ACLF by inhibiting necroptosis. To test this hypothesis, we first assessed the expression of GAL3 in control and fibrotic mice with or without acute insult. Second, loss- and gain-of-function experiments of GAL3 were performed. Third, the correlation between GAL3 and M2-like macrophage activation was analysed, and the potential role of GAL3 in M2-like macrophage-conferred hepatoprotection was confirmed. Finally, the molecular mechanism underlying GAL3-mediated hepatoprotection was dissected. GAL3 was found to be obviously upregulated in fibrotic mice with or without acute insult but not in acutely injured mice. Depletion of GAL3 aggravated hepatic damage in fibrotic mice upon insult. Conversely, adoptive transfer of GAL3 provided normal mice enhanced resistance against acute insult. The expression of GAL3 is closely correlated with M2-like macrophage activation. Through adoptive transfer and depletion experiments, M2-like macrophages were verified to act as a major source of GAL3. Importantly, GAL3 was confirmed to hold a pivotal place in the hepatoprotection conferred by M2-like macrophages through loss- and gain-of-function experiments. Unexpectedly, the depletion and adoptive transfer of GAL3 resulted in significant differences in the expression levels of pyroptosis but not necroptosis signalling molecules. Taken together, GAL3 plays a pivotal role in the hepatoprotection conferred by M2-like macrophages in ACLF by inhibiting pyroptosis but not necroptosis signalling. Our findings provide novel insights into the pathogenesis and therapy of ACLF.