bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantifying the Contribution of Ocean Advection and Surface Flux to the Upper‐Ocean Salinity Variability Resolved by Climate Model Simulations
Authors: Laurindo Lucas C. , Siqueira Leo , Small R. Justin , Thompson LuAnne , Kirtman Benjamin P. 
Published: February 2024

AbstractThis study examines the impact of ocean advection and surface freshwater flux on the non‐seasonal, upper‐ocean salinity variability in two climate model simulations with eddy‐resolving and eddy‐parameterized ocean components (HR and LR, respectively). We assess the realism of each simulation by comparing their sea surface salinity (SSS) variance with satellite and Argo float estimates. In the extratropics, the HR variance is about five times larger than that in LR and agrees with Argo. In turn, the extratropical satellite SSS variance is smaller than that from HR and Argo by about a factor of two, potentially caused by the insufficient resolution of radiometers to capture mesoscale features and their low sensitivity to SSS in cold waters. Using a simplified salinity conservation equation for the upper‐50‐m ocean, we find that the advection‐driven variance in HR is, on average, 10 times larger than the surface flux‐driven variance, reflecting the action of mesoscale processes.
Important Role of Low Cloud and Fog in Sulfate Aerosol Formation During Winter Haze Over the North China Plain
Authors: Cai Suyi , Liu Tengyu , Huang Xin , Song Yu , Wang Tiantian , Sun Zhaobin , Gao Jian , Ding Aijun 
Published: February 2024

AbstractSulfate aerosol greatly contributes to wintertime haze pollution in emission‐intensive regions like the North China Plain (NCP) in China. Fast sulfate increase and accumulation are usually recorded during winter haze; however, the multiphase oxidation of sulfur dioxide (SO2) and the physical processes affecting near‐surface sulfate are not fully understood. By combining in situ observations and numerical simulations, we found that high sulfur oxidation ratios (>0.6) under heavily polluted conditions are associated with low clouds and fog over NCP, induced by the moist southerly airflow. Thick low clouds and high SO2 levels in NCP provide a reaction environment for sulfate production. The sulfate production rate in cloud water can reach 0.5–1.3 μg m−3 h−1. The results demonstrate that the vertical mixing of sulfate generated within the cloud water to the surface plays a significant role in rapid sulfate production, highlighting the importance of understanding cloud‐water processes in haze pollution.
Ocean Biogeochemical Fingerprints of Fast‐Sinking Tunicate and Fish Detritus
Authors: Luo Jessica Y. , Stock Charles A. , Dunne John P. , Saba Grace K. , Cook Lauren 
Published: February 2024

AbstractPelagic tunicates (salps, pyrosomes) and fishes generate jelly falls and/or fecal pellets that sink roughly 10 times faster than bulk oceanic detritus, but their impacts on biogeochemical cycles in the ocean interior are poorly understood. Using a coupled physical‐biogeochemical model, we find that fast‐sinking detritus decreased global net primary production and surface export, but increased deep sequestration and transfer efficiency in much of the extratropics and upwelling zones. Fast‐sinking detritus generally decreased total suboxic and hypoxic volumes, reducing a “large oxygen minimum zone (OMZ)” bias common in global biogeochemical models. Newly aerobic regions at OMZ edges exhibited reduced transfer efficiencies in contrast with global tendencies. Reductions in water column denitrification resulting from improved OMZs improved simulated nitrate deficits relative to phosphate. The carbon flux to the benthos increased by 11% with fast‐sinking detritus from fishes and pelagic tunicates, yet simulated benthic fluxes remained on the lower end of observation‐based estimates.
Statistical Analysis of Mercury's Magnetotail Lobe Field Using MESSENGER Observations
Authors: Bowers Charles F. , Jackman Caitriona M. , Sun Weijie , Holmberg Mika K. G. , Jia Xianzhe , Griton Léa 
Published: February 2024

AbstractThe magnetotail lobe region at Mercury is characterized by low plasma density and low magnetic field variability compared to the nightside magnetosheath and central plasma sheet. At Mercury, as well as other planets, lobe magnetic fields play a crucial role in storing and releasing magnetic flux in response to changing upstream solar wind conditions such as interplanetary magnetic field (IMF) orientation and solar wind dynamic pressure (Pdyn). This makes the region significant for studying the magnetospheric interaction with the intense solar wind conditions at Mercury's orbit. Here, we identify and analyze magnetotail lobe observations made by the Mercury Surface, Space Environment, Geochemistry and Ranging (MESSENGER) spacecraft during its 4 years orbital phase. We empirically determined a set of criteria using magnetometer (MAG) and the Fast Imaging Plasma Spectrometer instruments onboard MESSENGER to identify lobe magnetic field intervals. From 3,332 MESSENGER orbits, we identify 1,242 lobe field intervals. We derive an expression for the average lobe magnetic field strength in nanotesla with respect to radial distance downtail: Blobe(r) = (135 ± 8) * r(−2.1±0.3) + (31 ± 8). The lobe magnetic field exhibits both small‐scale (∼3 min) and orbit‐to‐orbit (∼8–12 hr) variability in magnetic field strength compared to this averaged field strength expression. The orbit‐to‐orbit variability in lobe field strength is not significantly correlated with estimated IMF orientation, but is directly correlated with Pdyn. Thus, our findings provide evidence for the pressure balance between the inward facing Pdyn on the nightside magnetopause and the outward facing magnetic pressure supplied by the lobes.
Occurrence Probability of Magnetic Field Disturbances Measured With Swarm: Mapping the Dynamic Magnetosphere‐Ionosphere Coupling
Authors: Decotte Margot , Laundal Karl M. , Hatch Spencer M. , Reistad Jone P. 
Published: February 2024

AbstractThe exchange of kinetic and electromagnetic energy by precipitation and/or outflow and through field‐aligned currents are two aspects of the ionosphere‐magnetosphere coupling. A thorough investigation of these processes is required to better understand magnetospheric dynamics. Building on our previous study using the Defense Meteorological Satellite Program spectrometer data, here we use Swarm vector field magnetometer data to describe the auroral zone morphology in terms of east‐west magnetic field perturbations. We define a threshold for detecting magnetic fluctuations based on the power spectral density of ΔBEW, and derive the disturbed magnetic field occurrence probability (dBOP) at low [0.1–1 Hz] and high [2.5–5 Hz] frequencies. High‐frequency distributions of dBOP reveal a dayside‐nightside asymmetry, whereas low‐frequency dBOP exhibits a persistent morphological asymmetry between the dawn‐to‐noon and the dusk‐to‐midnight sectors, peaking at dawn. Notably, weak solar wind conditions are associated with an increase in the dBOP asymmetric patterns. At low frequency in particular, while the dBOP seems to be primarily constant at dawn, the dusk dBOP decreases during quiet times, inducing a relatively larger dawn‐dusk asymmetry in such conditions. Furthermore, based on a comparison analysis between low‐frequency dBOP and auroral electron precipitation occurrence probability, we suggest that both types of distribution offer a more comprehensive understanding of the large‐scale auroral zone when considered concurrently. Our interpretation is that the dBOP at low frequencies reflects a quasi‐steady state circulation of energy, while the high‐frequency dBOP reflects the regions of rapid changes in the magnetosphere. The dBOP is therefore a crucial source of information regarding the magnetosphere‐ionosphere coupling.
Evidence for a Current System and Potential Structure in the Martian Magnetotail
Authors: Nauth Murti , Mitchell David L. , Fowler Christopher M. , de Pater Imke , Azari Abigail R. 
Published: February 2024

AbstractWe present a case study of plasma and magnetic field observations in the Martian magnetotail using data from the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission during an orbit when the spacecraft was in the optical shadow, past the dusk terminator and downstream of the strongest crustal magnetic fields. In this region, we observed multiple magnetic field rotations (a signature of currents) closely associated with energized (up to 100 eV) electron populations. Several transitions between closed and draped magnetic topologies also occur in this region, which are likely to be caused by magnetic reconnection between the interplanetary magnetic field (IMF) and crustal magnetic fields. We also observe two regions of energized, counter‐streaming electrons, which are rare in the magnetotail, but twice as likely to occur downstream of strong crustal magnetic fields when they are near the evening terminator. Together, the multiple magnetic field rotations, topological changes, and counter streaming electrons suggest the presence of an electric potential structure similar to those observed above the auroral arc regions at Earth.
Ionospheric Conductances Due To Electron and Ion Precipitations: A Comparison Between EISCAT and DMSP Estimates
Authors: Wang Xin , Cai Lei , Aikio Anita , Vanhamäki Heikki , Virtanen Ilkka , Zhang Yongliang , Luo Bingxian , Liu Siqing 
Published: February 2024

AbstractEnergetic particle precipitation is the major source of electron production that controls the ionospheric Pedersen and Hall conductances at high latitudes. Many studies use empirical formulas to estimate conductances. The particle precipitation spectra measured by the Defense Meteorological Satellite Program (DMSP) Special Sensor J are often used as the input to the empirical formulas. In this study, we evaluate the empirical formulas of ionospheric conductances during four different types of auroral precipitation conditions based on 63 conjugate events observed by DMSP and EISCAT. The conductances calculated from the DMSP data with the empirical formulas are compared with those based on EISCAT measurements with the standard equations. The best correlation between these two is found when the empirical Robinson formulas (Robinson et al., 1987, https://doi.org/10.1029/ja092ia03p02565) are used in the presence of diffuse electron precipitation without ions. In the presence of ion precipitation, the correlation coefficients are smaller, but the correlation improves when the Galand formulas (Galand & Richmond, 2001, https://doi.org/10.1029/1999ja002001) are used to estimate the contribution of ion precipitation to the conductances. We also found that pure ion precipitation can cause the increase of conductances up to 2–7 S for Pedersen and 2.5–10 S for Hall conductances, which is positively correlated with the auroral electrojet index. Overall, the empirical formulas applied to the DMSP particle spectra underestimate the ionospheric conductances.
Stable Zirconium Isotopic Compositions of the Metasomatized Mantle
Authors: Zou Zongqi , Xu Yi‐Gang , Wang Zaicong , Hu Chuyu , Feng Lanping , Guo Jing‐Liang , Zhang Wen , Ma Liang , Hu Zhaochu , Liu Yongsheng 
Published: February 2024

AbstractMantle metasomatism, which affects the geochemical and lithological properties of the Earth, is crucial to the evolution and modification of the Earth's interior. Variations in chemical proxy of metasomatism, including high‐field strength elements (HFSE, e.g., Zr‐Ti isotopes and isovalent Zr‐Hf), have been commonly utilized as a tool to unravel the processes associated with the evolution of the Earth. However, the impact of mantle metasomatism by diverse agents on the Zr isotopic compositions of metasomatized mantle remains poorly understood. Here we carried out high‐precision double‐spike δ94/90Zr measurements for a suite of basalts, which were derived from the mantle sources metasomatized by typical metasomatic agents of fluid, silicate melt and carbonate melt originating from the deep mantle or recycled crustal materials. Mantle metasomatism results in lithological diversities within the mantle, ranging from hybridized peridotites to pyroxenite/eclogite and carbonated eclogite, which can significantly fractionate the isovalent HFSEs. However, our data show that these basalts have primitive mantle‐like δ94ZrNIST values (−0.033–0.043 ‰), regardless of their superchondritic Zr/Hf. The primitive mantle‐like δ94ZrNIST, irrelevant to any proxy of metasomatism (e.g., Sr‐Nd isotopes, Zr/Hf and La/Sm), indicate that mantle metasomatism and subsequence melting produce no measurable Zr isotopic variations in metasomatized mantle‐derived basalts. The δ94ZrNIST of basalts thus can be representative of the mean metasomatized mantle compositions. Combined with previously reported komatiites and oceanic basalts, we show that the Earth's mantle displays consistent δ94ZrNIST (−0.013 ± 0.053 ‰), even if it has a secular dynamic evolution with the interaction between Earth's exterior and interior.
Hydrology Controls Dissolved Organic Carbon and Nitrogen Export and Post‐Storm Recovery in Two Arctic Headwaters
Authors: Shogren Arial J. , Zarnetske Jay P. , Abbott Benjamin W. , Grose Amelia L. , Rec Abigail F. , Nipko Jansen , Song Chao , O’Donnell Jonathan A. , Bowden William B. 
Published: February 2024

AbstractClimate change is rapidly altering hydrological processes and consequently the structure and functioning of Arctic ecosystems. Predicting how these alterations will shape biogeochemical responses in rivers remains a major challenge. We measured [C]arbon and [N]itrogen concentrations continuously from two Arctic watersheds capturing a wide range of flow conditions to assess understudied event‐scale C and N concentration‐discharge (C‐Q) behavior and post‐event recovery of stoichiometric conditions. The watersheds represent low‐gradient, tundra landscapes typical of the eastern Brooks Range on the North Slope of Alaska and are part of the Arctic Long‐Term Ecological Research sites: the Kuparuk River and Oksrukuyik Creek. In both watersheds, we deployed high‐frequency optical sensors to measure dissolved organic carbon (DOC), nitrate (), and total dissolved nitrogen (TDN) for five consecutive thaw seasons (2017–2021). Our analyses revealed a lag in DOC: stoichiometric recovery after a hydrologic perturbation: while DOC was consistently elevated after high flows, diluted during rainfall events and consequently, recovery in post‐event concentration was delayed. Conversely, the co‐enrichment of TDN at high flows, even in watersheds with relatively high N‐demand, represents a potential “leak” of hydrologically available organic N to downstream ecosystems. Our use of high‐frequency, long‐term optical sensors provides an improved method to estimate carbon and nutrient budgets and stoichiometric recovery behavior across event and seasonal timescales, enabling new insights and conceptualizations of a changing Arctic, such as assessing ecosystem disturbance and recovery across multiple timescales.
Using Stochastic Point Pattern Analysis to Track Regional Orientations of Magmatism During the Transition to Cenozoic Extension and Rio Grande Rifting, Southern Rocky Mountains
Authors: Rosera J. M. , Gaynor S. P. , Ulianov A. , Schaltegger U. 
Published: February 2024

AbstractThe southern Rocky Mountains in Colorado and northern New Mexico hosted intracontinental magmatism that developed during a tectonic transition from shortening (Laramide orogeny, ca. 75 to 40 Ma) through extension and rifting. We present a novel approach that uses stochastic weighted bootstrap simulations of a large set of new and historical geochronology data to better understand how regional anisotropies responsible for focusing magma emplacement evolved through time. This technique can detect subtle trends in directional distributions, including multi‐modal orientations, and can be filtered from regional to local scales. Our results indicate that magmatism followed first the northeast trend of the Colorado mineral belt between 75 and 40 Ma and deviated afterward. These deviations vary depending on the scale of the analysis. At the smallest scale we evaluated (<75 km), the orientation of magmatism from 45 to 30 Ma rotated counter‐clockwise before aligning with the north‐south trend of the modern Rio Grande rift. Larger, regional‐scale analyses indicate magma centers between 40 to 35 Ma and 25 to 20 Ma were dominantly oriented southwest‐northeast, whereas magmatism between 35 and 25 Ma had north‐south orientation. The large areal footprint of magmatism and shifting regional patterns suggest that ancient zones of weakness in the North American lithosphere accommodated magma flow at different moments in time, rather than controlled by a retreating interface of the Farallon and North American plates.
Predicting Imminent Cyanobacterial Blooms in Lakes Using Incomplete Timely Data
Authors: Heggerud Christopher M. , Xu Jingjing , Wang Hao , Lewis Mark A. , Zurawell Ron W. , Loewen Charlie J. G. , Vinebrooke Rolf D. , Ramazi Pouria 
Published: February 2024

AbstractToxic cyanobacterial blooms (CBs) are becoming more frequent globally, posing a threat to freshwater ecosystems. While making long‐range forecasts is overly challenging, predicting imminent CBs is possible from precise monitoring data of the underlying covariates. It is, however, infeasibly costly to conduct precise monitoring on a large scale, leaving most lakes unmonitored or only partially monitored. The challenge is hence to build a predictive model that can use the incomplete, partially‐monitored data to make near‐future CB predictions. By using 30 years of monitoring data for 78 water bodies in Alberta, Canada, combined with data of watershed characteristics (including natural land cover and anthropogenic land use) and meteorological conditions, we train a Bayesian network that predicts future 2‐week CB with an area under the curve (AUC) of 0.83. The only monitoring data that the model needs to reach this level of accuracy are whether the cell count and Secchi depth are low, medium, or high, which can be estimated by advanced high‐resolution imaging technology or trained local citizens. The model is robust against missing values as in the absence of any single covariate, it performs with an AUC of at least 0.78. While taking a major step toward reduced‐cost, less data‐intensive CB forecasting, our results identify those key covariates that are worth the monitoring investment for highly accurate predictions.
A Semi‐Analytical Solution for the Equivalent Permeability Coefficient of the Multilayered Porous Medium With Continuous Fracture
Authors: Zhang Shuai , Liu Xiaoli 
Published: February 2024

AbstractFractures significantly alter the permeability characteristics of the natural porous media, especially for the multilayered porous medium system. The most direct and effective approach to assess the hydraulic conductivity of a multilayered porous medium with continuous fracture is to determine its equivalent permeability coefficient (EPC). A mathematical model with second‐order accuracy is established to analysis the permeability characteristics of the multilayered porous medium incorporating a continuous fracture. The Navier‒Stokes equation is used to govern the clear fluid motion in the continuous fracture, and the seepage fluid motion in the multilayered porous matrix is governed by the Brinkman‒Darcy equation. The semi‐analytical solutions for the velocity profile and EPC of the present model are derived under the conditions of the jumping stress at the fracture‐matrix interface and the continuous velocity at the matrix(i)‐matrix(i +1) interface. The Lattice Boltzmann method, finite element method, and one domain method simulations are conducted to verify the deduced semi‐analytical solutions of the velocity profile. Furthermore, the calculated EPC of the present multilayered model is in good agreement with that of the existing classic models (i.e., one region: fracture, two regions: fracture‐matrix, three regions: fracture‐matrix1‐matrix2, and multilayered porous medium without fracture). Parameter sensitivity reveals that increasing the thickness, dip angle, and porosity of the fractured porous media increases the flow velocity, while an increase in the stress jump coefficient can result in the opposite effect. This implies that porous layers containing fracture are more susceptible to erosion, particularly under conditions of steep dip angle and strong permeability.
Finding a balance in reduced toxicity hematopoietic stem cell transplantation for thalassemia: role of infused CD3+ cell count and immunosuppression
Authors: Meissner Barbara , Lang Peter , Bader Peter , Hoenig Manfred , Müller Ingo , Meisel Roland , Greil Johann , Sauer Martin G. , Metzler Markus , Corbacioglu Selim , Burkhardt Birgit , Wölfl Matthias , Strahm Brigitte , Kafa Kinan , Basu Oliver , Lode Holger N. , Gruhn Bernd , Cario Holger , Ozga Ann-Kathrin , Zimmermann Martin , Jarisch Andrea , Beier Rita 
Published: February 2024

AbstractWe performed a retrospective analysis on 124 patients with transfusion-dependent thalassemia who were registered in the German pediatric registry for stem cell transplantation. All patients underwent first allogeneic hematopoietic stem cell transplantation (HSCT) between 2011 and 2020 and belonged mainly to Pesaro risk class 1–2. Four-year overall (OS) and thalassemia-free survival (TFS) were 94.5% ± 2.9% and 88.0% ± 3.4% after treosulfan-fludarabine-thiotepa- and 96.9% ± 3.1% (P = 0.763) and 96.9% ± 3.1% (P = 0.155) after busulfan-fludarabine-based conditioning. Mixed chimerism below 75% occurred predominantly in treosulfan-based regimens (27.5% versus 6.2%). OS and TFS did not differ significantly between matched sibling, other matched family and matched unrelated donor (UD) HSCTs (OS: 100.0%, 100.0%, 96.3% ± 3.6%; TFS: 96.5% ± 2.4%, 90.0% ± 9.5%, 88.9% ± 6.0%). However, mismatched UD-HSCTs performed less favorable (OS: 84.7% ± 7.3% (P = 0.029); TFS: 79.9% ± 7.4% (P = 0.082)). We generated a scoring system reflecting the risk to develop mixed chimerism in our cohort. The main risk-reducing factors were a high CD3+ cell count (≥6 × 107/kg) in the graft, busulfan-conditioning, pre-conditioning therapy and low-targeted ciclosporin A trough levels. Acute GvHD grade III-IV in treosulfan-based concepts predominantly occurred in patients with UD and reduced GvHD prophylaxis but not in the context of high CD3+ cell doses. Taken together, this information might be used to develop more risk-adapted HSCT regimens for thalassemia patients.