bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Method to Determine Moment Magnitudes of Large Earthquakes Based on the Long‐Period Coda
Authors: Jiang Xinyu , Song Xiaodong 
Published: June 2022

AbstractWe present a novel and robust method for estimating moment magnitudes (Mw) of large earthquakes with long‐period and long‐lasting coda energy. Fitting the energy with a simple decay model, we derive a straightforward relationship between the coda energy and the Mw. Tests with both real and synthetic data of 10 globally distributed large earthquakes (Mw > 8) verify the method and the results are stable and reliable even with a fast calculation of synthetics for a 1D model. Tests also show that the method is applicable for earthquakes with Mw above 7.5–8.0 with energy sufficiently greater than the ambient noise. The method removes or reduces the effects of geometric spreading, focal mechanism, source rupture process, and the actual Earth structure, making it advantageous for estimating the magnitudes of large earthquakes. The new long‐period coda moment magnitude (Mwo) estimations are similar to the conventional solutions but are slightly larger (by 0.04 on average).
Plankton Imagery Data Inform Satellite‐Based Estimates of Diatom Carbon
Authors: Chase A. P. , Boss E. S. , Haëntjens N. , Culhane E. , Roesler C. , Karp‐Boss L. 
Published: June 2022

AbstractEstimating the biomass of phytoplankton communities via remote sensing is a key requirement for understanding global ocean ecosystems. Of particular interest is the carbon associated with diatoms given their unequivocal ecological and biogeochemical roles. Satellite‐based algorithms often rely on accessory pigment proxies to define diatom biomass, despite a lack of validation against independent diatom biomass measurements. We used imaging‐in‐flow cytometry to quantify diatom carbon in the western North Atlantic, and compared results to those obtained from accessory pigment‐based approximations. Based on this analysis, we offer a new empirical formula to estimate diatom carbon concentrations from chlorophyll a. Additionally, we developed a neural network model in which we integrated chlorophyll a and environmental information to estimate diatom carbon distributions in the western North Atlantic. The potential for improving satellite‐based diatom carbon estimates by integrating environmental information into a model, compared to models that are based solely on chlorophyll a, is discussed.
Persistent Magma‐Rich Waves Beneath Mid‐Ocean Ridges Explain Long Periodicity on Ocean Floor Fabric
Authors: Sim S. J. 
Published: June 2022

AbstractThe ocean floor makes up the majority of the Earth's surface and yet, its geomorphology is not fully understood. Recent debate has focused on whether sea level changes—driven by Milankovitch glacial cycles—generate the abyssal hill fabric of the ocean floor by modulating mid‐ocean ridge magma supply. However, periodicities longer than Milankovitch cycles are prominent in the ocean bathymetry. Using crustal thickness estimates from two‐phase flow simulations of ridge magma transport, I show that persistent melt‐rich porosity waves could be responsible for the ocean floor fabric at periods of 100 kyr and longer, except in the case of fast‐spreading ridges. For periods longer than 100 kyr, spectral energy is notably present at large mantle permeabilities regardless of spreading rates. Therefore, two‐phase flow models can provide constraints on elusive mantle parameters such as permeability and viscosity when directly linked to the ocean floor fabric produced.
Crust and Uppermost Mantle Magma Plumbing System Beneath Changbaishan Intraplate Volcano, China/North Korea, Revealed by Ambient Noise Adjoint Tomography
Authors: Fan Xingli , Guo Zhen , Zhao Yang , Chen Qi‐Fu 
Published: June 2022

AbstractChangbaishan volcano (CBV), straddling the border between China and North Korea, is one of the most intriguing and explosive volcanoes on Earth owing to its voluminous Holocene eruptions and unusual magma composition within a continental intraplate setting. Despite the enormous size and destructive past, its underlying magma plumbing system remains debated and poorly understood. We present a refined high‐resolution 3D crust and uppermost mantle S‐wave velocity (Vs) model of CBV by applying advanced 3D full‐waveform adjoint tomography on seismic ambient noise data recorded in both China and North Korea. The newly obtained seismic images detail a 3D architecture of magma plumbing systems beneath CBV, characterized by the presence of a prominent lower‐crustal mush zone with an estimated melt fraction of ∼1.5%–3.6%, which is sourced from upwelling asthenosphere through a vertical narrow conduit in the uppermost mantle region that contains an estimated melt fraction of ∼6%.
Snow Crash: Compaction Craters on (486958) Arrokoth and Other Small KBOs, With Implications
Authors: McKinnon William B. , Mao Xiaochen , Schenk P. M. , Singer K. N. , Robbins S. J. , White O. L. , Beyer R. A. , Porter S. B. , Keane J. T. , Britt D. T. , Spencer J. R. , Grundy W. M. , Moore J. M. , Stern S. A. , Weaver H. A. , Olkin C. B. 
Published: June 2022

AbstractEvidence from Arrokoth and comets strongly suggests a very low density for this and similar small Kuiper belt objects. Plausible compositions imply high porosities, in excess of 70%, and low compaction crush strengths. If so, impact craters on Arrokoth (especially Sky, its largest) formed largely by compaction of pore space and material displacement. This is consistent with geological evidence from New Horizons imaging. High porosity reduces cratering efficiency in the gravity regime whereas compaction moves it toward crush strength scaling and increased efficiency. Compaction also guarantees that most impactor kinetic energy is taken up as waste heat near the impact point, with momentum transferred to the rest of the body by elastic waves only. Monte Carlo simulations of Sky‐forming conditions indicate that the momentum imparted likely separated Arrokoth's two lobes, but displacement was limited by dissipation at the neck between them. Unusual strength properties are not required to preserve Arrokoth's bilobate configuration.
Amplification of Plunging Flows in Bedrock Canyons
Authors: Hurson Max , Venditti Jeremy G. , Rennie Colin D. , Kwoll Eva , Fairweather Kirsti , Haught Dan R. W. , Kusack Kyle M. , Church Michael 
Published: June 2022

AbstractBedrock river erosion is driven by channel hydraulics, which are not well understood for complex morphologies. Many bedrock rivers exhibit a constriction‐pool‐widening (CPW) morphology associated with submerged plunging flows. These flows cause velocity profile inversions resulting in high velocities near the bed and low velocities on the water surface. The first observations documenting plunging flows were from relatively low discharge, and it is unclear whether they persist during floods. Here we show that plunging flows persist and get stronger at flood discharge, increasing bedrock erosion potential by particle impacts. Flood‐discharge plunging flows contact the bed and maintain high velocities farther through the CPW structure, and evacuate large volumes of sediment from the pools. These reach‐scale processes are not represented in large‐scale landscape evolution models, yet these erosion mechanisms set the pace of landscape evolution, begging for a re‐evaluation of process representation in landscape evolution models.
Does Large‐Scale Crustal Flow Shape the Eastern Margin of the Tibetan Plateau? Insights From Episodic Magmatism of Gongga‐Zheduo Granitic Massif
Authors: Hu Fangyang , Wu Fu‐Yuan , Ducea Mihai N. , Chapman James B. , Yang Lei 
Published: June 2022

AbstractThe mechanisms driving crustal deformation and uplift of orogenic plateaus are fundamental to continental tectonics. Large‐scale crustal flow has been hypothesized to occur in eastern Tibet, but it remains controversial due to a lack of geologic evidence. Geochemical and isotopic data from Cenozoic igneous rocks in the eastern Tibet‐Gongga‐Zheduo intrusive massif, provide a way to test this model. Modeling results suggest that Cenozoic magmas originated at depths of ∼30–40 km, the depth that crustal flow has been postulated to occur at. Detailed isotopic analyses indicate that the igneous rocks are derived from partial melting of the local Songpan‐Ganzi crust, arguing against a long‐distance crustal flow. Episodic magmatism during the Cenozoic showing a repeated shifting of magmatic sources can be correlated with crustal uplift. The continued indentation of the Indian Block and upwelling of the asthenosphere contribute to the crustal deformation, magmatism, and uplift.
The Geoeffectiveness of Solar Wind Current Sheets and Its Modulation by Foreshock Ions
Authors: Wang Boyi , Wang Yi , Liu Terry Z. , Angelopoulos Vassilis 
Published: June 2022

AbstractWe examined the evolution of 34 solar wind bifurcated current sheets in the magnetosheath and their magnetospheric responses, using the in‐situ observations of the THEMIS probes and the GOES satellites. The role of foreshock ions in that process is also determined. The first current sheet event did not exhibit any modulation by foreshock ions; it generated a dynamic pressure plateau, which further evolved into a dynamic pressure plateau in the magnetosheath and likely generated mirror mode waves in the magnetosphere. The second event exhibits foreshock ions which enhanced the perturbations in the current sheet due to the disappearance and reappearance of foreshock ions controlled by the direction changes of magnetic field. That current sheet further compressed the magnetosphere and drove stronger magnetic field oscillations than the first event. Thus, solar wind current sheets can be geoeffective and their geoeffectiveness can be amplified by the foreshock ions inside their structures.
Observational Evidence for the Origin of Repetitive Chorus Emissions
Authors: Gao Xinliang , Chen Rui , Lu Quanming , Chen Lunjin , Chen Huayue , Wang Xueyi 
Published: June 2022

AbstractChorus waves, discovered as a series of repetitive coherent emissions, are well known for producing hazard radiation environments in Earth's magnetosphere. Its repetitive nature directly causes the rapid modulation of pulsating aurora in the upper atmosphere and microburst in the ionosphere, but its origin remains a decades‐old puzzle. Recent simulation suggested the energetic electrons, injected from the magnetotail and drifting eastward around the Earth, are critical to form the repetitive pattern. Based on a survey of 1.5 year data from Van Allen Probes, we provide the first observational evidence for the origin of repetitive chorus emissions. We find there exists universally an inverse correlation between the repetitive period and drift velocity of energetic electrons, uncovering how the drifting energetic electrons tune the repetitive period of chorus emissions, which is also supported by kinetic simulations. Our finding may apply to understand the generation of repetitive emissions in planetary magnetospheres and laboratory plasmas.
The Response of Radiative Forcing to High Spatiotemporally Resolved Land‐Use Change and Transition From 1982 to 2010 in China
Authors: Jian Xiaohu , Zhang Xiaodong , Liu Yijie , Liu Xinrui , Chen Kaijie , Wang Linfei , Li Jixiang , Zhao Yuan , Luo Jinmu , Zhugu Ruiyu , Ma Jianmin 
Published: June 2022

AbstractSignificant uncertainties remain in the estimate of radiative forcing (RF) induced by land‐use change (LUC), partially attributable to the lack of reliable LUC data with a high spatiotemporal resolution. We implemented a high spatiotemporally resolved LUC data set in an earth system model (OSCAR) to examine the response of RF to LUC from 1982 to 2010 in China. Results were compared with the RF estimated using a low spatiotemporally resolved LUC inventory employed previously. The updated LUC data set reduces negative RF by −3.8% from 2000 to 2010 due to the changes in surface albedo subject to LU transition. The simulated mean RF driven by CO2 associated with LUC from 1982 to 2010 using a high spatiotemporally resolved LUC data set reached 0.074 W m−2, considerably higher than 0.022 W m−2 of mean RF derived from the low spatiotemporally resolved LUC inventory, implying increasing net RF and more substantial LUC induced warming.
Continuous Loss of Global Lake Ice Across Two Centuries Revealed by Satellite Observations and Numerical Modeling
Authors: Wang Xinchi , Feng Lian , Qi Wei , Cai Xiaobin , Zheng Yi , Gibson Luke , Tang Jing , Song Xiao‐peng , Liu Junguo , Zheng Chunmiao , Bryan Brett A. 
Published: June 2022

AbstractLake ice loss has been detected worldwide due to recent climate warming, yet spatially and temporally detailed information on the changes in global ice phenology does not exist. Here, we build a global lake ice phenology database comprising three lake ice phenologies—freeze‐up, break‐up, and ice duration—for each year across two centuries (1900–2099). The timing of all three phenologies experienced mild but statistically significant warming trends in the 20th century; continued warming trends were detected in ∼60% of the lakes from 2001 to 2020. Under a high emissions scenario (RCP 8.5), future global median ice duration would be shortened by 49.9 days by the end of the 21st century; such change can be substantially reduced under lower emission scenarios. We revealed continuous loss of global lake ice during the observed period, our generated database provides critical baseline information to evaluate the consequences of historical and future lake ice changes.
Scaling the Mixing Efficiency of Sediment‐Stratified Turbulence
Authors: Tu Junbiao , Fan Daidu , Liu Zhiyu , Smyth William 
Published: June 2022

AbstractThe flux Richardson number Rf, also called the mixing efficiency of stratified turbulence, is important in determining geophysical flow phenomena such as ocean circulation and air‐sea transports. Measuring Rf in the field is usually difficult, thus parameterization of Rf based on readily observed properties is essential. Here, estimates of Rf in a strongly turbulent, sediment‐stratified estuarine flow are obtained from measurements of covariance‐derived turbulent buoyancy fluxes (B) and spectrally fitted values of the dissipation rate of turbulent kinetic energy (ε). We test scalings for Rf in terms of the buoyancy Reynolds number (Reb), the gradient Richardson number (Ri), and turbulent Froude number (Frt). Neither the Reb‐based nor the Ri‐based scheme is able to describe the observed variations in Rf, but the Frt‐based parameterization works well. These findings support further use of the Frt ‐ based parameterization in turbulent oceanic and estuarine environments.
Cascading Drought‐Heat Dynamics During the 2021 Southwest United States Heatwave
Authors: Osman M. , Zaitchik B. F. , Winstead N. S. 
Published: June 2022

AbstractIn June of 2021 the Southwest United States experienced a record‐breaking heatwave. This heatwave came at a time when the region was in severe drought. As drought alters the surface energy budget in ways that affect lower atmosphere temperature and circulations, it is possible that the combined drought‐heat event was a cascading climate hazard, in which preexisting drought exacerbated the heatwave. We apply satellite observation and numerical experiments with the Weather Research and Forecasting (WRF) model to test for land‐atmosphere feedbacks during the heatwave consistent with drought influence. We find a modest positive drought‐heat effect, as WRF simulations that include the drought have marginally higher air temperatures than those that exclude the initial drought conditions, with more substantial effects in wetter, forested areas. Evidence of drought‐heat‐drought‐coupled feedbacks was similarly modest in our simulations, as accounting for drought preconditioning led to a small reduction in simulated precipitation in the region.
Relative Permeability of Hydrogen and Aqueous Brines in Sandstones and Carbonates at Reservoir Conditions
Authors: Rezaei Amin , Hassanpouryouzband Aliakbar , Molnar Ian , Derikvand Zeinab , Haszeldine R. Stuart , Edlmann Katriona 
Published: June 2022

AbstractGeological hydrogen storage in depleted gas fields represents a new technology to mitigate climate change. It comes with several research gaps, around hydrogen recovery, including the flow behavior of hydrogen gas in porous media. Here, we provide the first‐published comprehensive experimental study of unsteady state drainage relative permeability curves with H2‐Brine, on two different types of sandstones and a carbonate rock. We investigate the effect of pressure, brine salinity, and rock type on hydrogen flow behavior and compare it to that of CH4 and N2 at high‐pressure and high‐temperature conditions representative of potential geological storage sites. Finally, we use a history matching method for modeling relative permeability curves using the measured data within the experiments. Our results suggest that nitrogen can be used as a proxy gas for hydrogen to carry out multiphase fluid flow experiments, to provide the fundamental constitutive relationships necessary for large‐scale simulations of geological hydrogen storage.
Direct Observation of Acceleration and Thermalization of Beam Electrons Caused by Double Layers in the Earth's Plasma Sheet
Authors: Yuan Zhigang , Dong Yue , Huang Shiyong , Xue Zuxiang , Yu Xiongdong 
Published: June 2022

AbstractWe report direct observations of the detailed processes for the acceleration and thermalization of beam electrons in the plasma sheet (PS) of the Earth's magnetotail. With observations from the four magnetospheric multiscale (MMS) satellites, the potential of a double layer (DL) structure is found to be mostly consistent with enhancements of the averaged parallel energy of the beam electrons passing through the DL structure, demonstrating that beam electrons are accelerated by the DL structure. Thereafter, Debye‐scale parallel electric field turbulences and an increase of the parallel temperature are simultaneously observed, implying that electrostatic parallel turbulences thermalize beam electrons. These observations imply that the DL is a key process controlling the acceleration and thermalization of beam electrons in the PS of the Earth's magnetotail.
Butterfly Distribution of Relativistic Electrons Driven by Parallel Propagating Lower Band Whistler Chorus Waves
Authors: Saito S. , Miyoshi Y. 
Published: June 2022

AbstractWe report results from a test particle simulation to reveal that electron scattering driven by lower band whistler chorus waves propagating along a magnetic field line plays an important role to produce the butterfly distribution of relativistic electrons. The results show that two nonlinear scattering processes, which are the phase trapping and the dislocation process, contribute to the formation of the butterfly distribution within a minute. We confirm that the quasilinear diffusion estimated from the whistler chorus waves are too slow to reproduce the butterfly distribution within a minute. The simulation results also show that there is the upper limit of rapid electron acceleration. We expect that the upper limit of the rapid flux enhancement is an evidence that the phase trapping process contributes to relativistic electron acceleration in the heart of the outer radiation belt.
Multispecies MHD Study of Ion Escape at Ancient Mars: Effects of an Intrinsic Magnetic Field and Solar XUV Radiation
Authors: Sakata R. , Seki K. , Sakai S. , Terada N. , Shinagawa H. , Tanaka T. 
Published: June 2022

AbstractIon escape is one of the key processes responsible for drastic climate change on ancient Mars. Ion escape is affected by the solar X‐ray and EUV (X‐ray and extreme ultraviolet (XUV)) flux, the solar wind, and the presence of a planetary intrinsic magnetic field, all of which was much different at ancient Mars. We investigated how the presence and strength of a dipole field affects the ion escape under 50 or 10 times higher solar XUV flux and strong solar wind with multispecies magnetohydrodynamics model. The results showed two opposite effects on the escape rates, which is associated with the pressure ratio of the dipolar magnetic pressure at the equatorial surface to the solar wind dynamic pressure. The escape rates increase by up to a factor of 6 for O2+ and CO2+ but change little for O+ if the pressure ratio is below 0.1. On the other hand, the escape rates decrease by more than one order of magnitude for the three ions if the pressure ratio is above 0.1. The threshold can be described by the pressure balance between the solar wind flow and the dipole field at high latitudes, where the ionospheric outflow emerges in the unmagnetized cases. The effects on the escape rates are stronger under lower solar XUV cases. The total escape rate reaches 1027 s−1 in the unmagnetized case, which may lead to a large contribution to atmospheric loss at ancient Mars, but it can be reduced by an order of magnitude in the presence of a dipole field.
Folic acid effect on homocysteine, sortilin levels and glycemic control in type 2 diabetes mellitus patients
Authors: El-khodary Noha M. , Dabees Hossam , Werida Rehab H. 
Published: June 2022

Abstract
Aim
The present study aimed to determine the folic acid supplement (FAS) effects on serum homocysteine and sortilin levels, glycemic indices, and lipid profile in type II diabetic patients.

Method
A double-blind randomized controlled clinical trial have been performed on 100 patients with T2DM randomly divided into two groups that received either placebo or folic acid 5 mg/d for 12 weeks.

Results
FAS caused a significant decrease in homocysteine and sortilin serum levels (28.2% and 33.7%, P < 0.0001, respectively). After 3 months of intervention, 8.7% decrease in fasting blood glucose (P = 0.0005), 8.2% in HbA1c (P = 0.0002), 13.7% in serum insulin (P < 0.0001) and 21.7% in insulin resistance (P < 0.0001) were found in the folic acid group, however no significant difference was observed in the placebo group. Serum hs-CRP level showed significant positive associations with sortilin (r = 0.237, P = 0.018), homocysteine (r = 0.308, P = 0.002) and fasting blood glucose (r = 0.342, P = 0.000). There were no significant changes in lipid profile in both groups after 12 weeks.

Conclusion
FAS might be beneficial for reducing homocysteine and sortilin levels, enhancing glycemic control, and improved insulin resistance in patients with T2DM.