bluuebunny/crossref_metadata_2025 huggingface dataset:
Frequency of enhanced food availability controlled the growth of bamboo corals in the Northwestern South China Sea
Authors: Wang Haozhuang , Jian Zhimin , Zhou Xiaoli , Dang Haowen , Wang Yue , Wang Xingxing , Jin Haiyan
Published: March 2024

Cold-water bamboo corals are promising high-resolution archives of paleoceanography and cold-water coral (CWC) development research. Nevertheless, obtaining accurate, high-resolution chronology of these corals are still challenging. In this study, organic nodes of the bamboo corals in the northwest South China Sea (SCS) were used for growth ring imaging, and counting, as well as radiocarbon analysis to establish the high-resolution coral chronology. Our results show that the ratios between the growth ring numbers and coral ages are ~8 (~6) for specimen at ~700 m before (after) 1997 AD, and ~2 for specimen at ~1400 m during the whole life-span. These ratios are two times the frequency of the enhanced particulate organic carbon (POC) flux that determines the frequency of enhanced food availability to the corals, at the corresponding water depths. In analogue to the modern suitable habitat of the thriving CWCs, the growth ring formation of bamboo corals is most likely controlled by the frequency of the enhanced POC flux. Furthermore, the coral chronology and annual to seasonal radial growth rate (RGR) were obtained based on growth ring counting and summarizing the widths of the growth rings, respectively. Correlation between the coral RGRs and the climatic parameters, i.e., the Pacific Decadal Oscillation, the ENSO and the East Asian Monsoons (EAMs) are consistent with the relationship between these climatic parameters. These results further confirm the validity of age model of bamboo corals based on the concentric ring counting.
Hillslope-controlled incision thresholds shape mountain range topography of the Northern Andes
Authors: Ott Richard , Scherler Dirk , Huppert Kimberly , Braun Jean , Bermudez Mauricio
Published: March 2024

Rivers have long been regarded as the drivers of mountain landscape evolution, with hillslopes following suite. In this view, rivers set the rate of base-level change at the bottom of hillslopes that passively adjust their geometry to attain a matching hillslope denudation rate. Hence, most large-scale landscape evolution studies focus on analyzing metrics of the river network, such as normalized river steepness (ksn). More recently, it has been recognized that ksn may depend on incision thresholds, a critical shear stress or unit stream power required to erode bedrock, which depend on sediment cover. In this study, we use previously published cosmogenic-nuclide derived erosion rate data from the Northern Andes to investigate how hillslope sediment delivery, controls incision thresholds and the first-order topography of two adjacent mountain ranges with different lithology.Our results suggest that the exponent of the power law between ksn and erosion rate, which we refer to as topographic insensitivity, is twice as high in the sedimentary rock-dominated Eastern Cordillera compared to the crystalline rock-dominated Central Cordillera. This generally means that in the Eastern Cordillera, spatial differences in erosion rate, e.g. induced by tectonic gradients, will only result in minor differences of river steepness compared to the Central Cordillera. We use river width measurements, discharge data, and channel grain size data to constrain a stochastic threshold incision model. Our results indicate that the difference in the erosion rate- ksn relationship can be explained by a 26 times higher incision threshold in the Eastern Cordillera. This difference in topographic insensitivity caused by incision thresholds cannot solely be explained by factors such as discharge variability, river width to discharge scaling, or channel grain size. However, we find a significantly higher landsliding frequency in the Eastern Cordillera that causes transient channel covering and damming, leading to a lower sensitivity of ksn to erosion rate. These findings highlight how hillslope-controlled sediment delivery can modify the stream response to tectonic uplift and exhibit a first-order control on the landscape evolution of adjacent mountain ranges.
Quantifying the surging process of the Kyagar Glacier in the Karakoram using successive digital elevation models and optical satellite images
Authors: Lv Mingyang
Published: March 2024

Glacier surges are prevalent in the Karakoram and often threaten local residents by submerging land and initiating secondary disasters. The Kyagar Glacier is well known for its surge history as it frequently blocked the downstream valley, leading to a series of high-magnitude glacial lake outburst floods. Although the surge dynamics of the Kyagar Glacier have been broadly described in the literature, there remains an extensive archive of remote sensing observations that have great potential for revealing specific surge characteristics and their relationship with historic lake outburst floods. We propose a new perspective on quantifying the surging process using successive digital elevation models (DEMs), which could be applied to other sites where glacier surges are known to occur. Advanced Spaceborne Thermal Emission and Reflection Radiometer DEMs, High Mountain Asia 8-meter DEMs, and the Shuttle Radar Topography Mission DEM were used to characterize surface elevation changes throughout the period from 2000 to 2021.We also used Landsat time series imagery to quantify glacier surface velocities and associated lake changes over the course of two surge events between 1989 and 2021. Using these datasets, we reconstruct the surging process of the Kyagar Glacier in unprecedented detail and find a clear signal of surface uplift over the lower glacier tongue, along with uniformly increasing velocities, associated with the period of surge initiation. Seasonal variations in surface flow are still evident throughout the surge phase, indicating the presence of water at the glacier bed. Surge activity of the Kyagar Glacier is strongly related to the development and drainage of the terminal ice-dammed lake, which is controlled by the drainage system beneath the glacier terminus.
Two distinct declining trend of autumn Arctic sea ice concentration before and after 2002
Authors: Jiang Zhina
Published: March 2024

This study investigates the Arctic sea ice concentration trend during 1979-2021 and explores why the autumn Arctic sea ice loss is accelerated after 2002 and its trend declining center shifts from the Chukchi Sea to the Barents-Kara-Laptev Seas. Attribution analysis reveals that the enhanced summer sea ice concentration negative trend in large part explains the autumn sea ice concentration accelerating reduction, whereas it is the trend center shift of increased downward longwave radiation that accounts for mostly of the autumn sea ice concentration decline center shift. Further analysis suggests the downward longwave radiation trend is closely related to large-scale atmospheric circulation changes. A tendency towards a dipole structure with an anticyclonic circulation over Greenland and the Arctic Ocean and a cyclonic circulation over Barents-Kara Seas enhances (suppresses) the downward longwave radiation over Western (Eastern) Arctic by warming and moistening (cooling and drying) the lower troposphere during 1979-2001. In comparison, a tendency towards a stronger Ural anticyclone combined with positive phase of the North Atlantic Oscillation pattern significantly promotes the increase of downward longwave radiation over Barents-Kara-Laptev Seas during 2002-2021. Our results set new insights into the Arctic sea ice variability and deepen our understanding of the climate change.
Altitudinal shifting of major forest tree species in Italian mountains under climate change
Authors: Noce Sergio , Cipriano Cristina , Santini Monia
Published: March 2024

Climate change has profound implications for global ecosystems, particularly in mountainous regions where species distribution and composition are highly sensitive to changing environmental conditions. Understanding the potential impacts of climate change on native forest species is crucial for effective conservation and management strategies. Despite numerous studies on climate change impacts, there remains a need to investigate the future dynamics of climate suitability for key native forest species, especially in specific mountainous sections. This study aims to address this knowledge gap by examining the potential shifts in altitudinal range and suitability for forest species in Italy's mountainous regions. By using species distribution models, through MaxEnt we show the divergent impacts among species and scenarios, with most species experiencing a contraction in their altitudinal range of suitability whereas others show the potential to extend beyond the current tree line. The Northern and North-Eastern Apennines exhibit the greatest and most widespread impacts on all species, emphasizing their vulnerability. Our findings highlight the complex and dynamic nature of climate change impacts on forest species in Italy. While most species are projected to experience a contraction in their altitudinal range, the European larch in the Alpine region and the Turkey oak in the Apennines show potential gains and could play significant roles in maintaining wooded populations. The tree line is generally expected to shift upward, impacting the European beech, a keystone species in the Italian mountain environment, negatively in the Alpine arc and Northern Apennines, while showing good future suitability above 1,500 meters in the Central and Southern Apennines. Instead, the Maritime pine emerges as a promising candidate for the future of the Southern Apennines. The projected impacts on mountain biodiversity, particularly in terms of forest population composition, suggest the need for comprehensive conservation and management strategies. The study emphasizes the importance of using high-resolution climate data and considering multiple factors and scenarios when assessing species vulnerability. The findings have implications at the local, regional, and national levels, emphasizing the need for continued efforts in producing reliable datasets and forecasts to inform targeted conservation efforts and adaptive management strategies in the face of climate change.
Effects of biochar and its co-application with inorganic and organic fertilizers on soil microbial respiration and temperature sensitivity of carbon mineralization.
Authors: Carpio Espinosa María José , Bonnefoy-Claudet Clément , Thévenot Mathieu , Mathieu Olivier , Benavente-Ferraces Iria , García-Gil Juan Carlos , Plaza César , Panettieri Marco
Published: March 2024

Biochar application to agricultural soils represents a strategy for carbon sequestration and soil quality enhancement. However, long-term field studies on the interactive effects of combined application of biochar and inorganic or organic fertilizers on temperature sensitivity of soil respiration (Q10) are still scarce. To address this gap, a long-term field experiment with a randomized block design was established in a semiarid agricultural soil in Central Spain in 2012. The treatments used for this study included unamended control, amendment with biochar (B) at a rate of 20 t ha-1 year-1, mineral fertilizer (MF), municipal compost (MC) and sewage sludge (SS) at rates to meet N crop demands and the co-amended B+MF, B+MC and B+SS applied at the same application rates used for the individual treatments. Soil samples were taken post-harvest of 2023, eight months after the latest soil amendments. A series of soil incubations were set to a range of 5-35 °C for CO2 measurements, which were addressed using the fully automated system Respicond respirometer X. Overall, Q10 values were not affected by the co-application of biochar and fertilizers. Only soils amended with MC showed a significant increase in the Q10 value in comparison to the B, MF and unamended control treatments. Furthermore, MC-amended soils showed higher respiration rates than those amended with SS. This difference could be attributed to the rapid mineralization of labile carbon fractions added with SS in preceding months or to the presence of preserved complex substrates in MC treatments that could decompose over the long-term. It could also be linked to a higher accumulation of SOC over the past 12 years in MC-treated soils compared to those treated with SS, thereby influencing the observed variations in respiration rates. On the other hand, co-application of biochar with fertilizers decreased soil CO2 fluxes, especially for B+MC and B+SS, in comparison to the treatments applied alone. The study suggests that in semiarid soils the combined application of biochar with other fertilizers may induce beneficial synergistic effects, creating a nutrient-rich soil environment while either limiting soil CO2 fluxes and mitigating the adverse impact on the temperature sensitivity of carbon mineralization. Acknowledgments: This research was supported by the Ministry of Science and Innovation (“BIOGEOCHAR” Project grant ref. TED2021-132342B-I00). M.J.C thanks to the Embassy of France in Spain for supporting her postdoctoral stay in the Biogéosciences Unit and MINECO for her “Juan de la Cierva-Formación” postdoctoral contract.
The New Operational of Indonesian Ocean Forecast System based on High Resolution Couple Atmosphere-Wave-Ocean Model (InaCAWO)
Authors: Alfahmi Furqon , Florida Nelly
Published: March 2024

InaCAWO is a new part of the Indonesian Ocean Forecast System (BMKG-OFS) that was developed by the Indonesian Agency for Meteorology, Climatology, and Geophysics in collaboration with NC State University and Baron Weather in 2023. BMKG-OFS has been operated since 2004 to provide marine weather predictions and ocean modeling, especially for the Indonesian sea area, continuously and in real-time conditions. In earlier stages, BMKG-OFS used wave modeling (Windwave-05, Wavewatch-III) with atmospheric modeling (WRF, GFS) as a forcing, separately. Couple modeling in these stages has the purpose of creating simulations with more accurate and realistic conditions.
The InacaWO model is built upon the COAWST model. It includes the regional oceanic model (ROMS), the atmospheric model (WRF), and the Simulating Wave Nearshore (SWAN) model. The system is linked to the Model Coupling Toolkit (MCT), a compilation of information modeling procedures. The spatial and temporal resolution of the model InaCAWO is approximately 3 km, with an hourly timestep, a 2036 x 1116 grid, and 70 vertical layers. ECMWF is used for initial and boundary conditions in atmospheric modeling, while MERCATOR is used for ocean modeling.
The atmospheric parameters of InacaWO have been evaluated using mean sea level, surface wind speed, and daily precipitation based on synoptic observations over a period of one year, despite the evaluation of ocean parameters based on satellite and drifter observations. The result indicates that the model's accuracy with contingency methods for all parameters is approximately 80%. InaCAWO is also capable of capturing a variety of unique Indonesian phenomena, such as the mixing process in Indonesian Throughflow with T-S Diagram, Eddy Circulations, Flow Intensifications in Narrow Straits, and Freshwater Discharge
SurfQuake (SQ): A new Python toolbox for the workflow process of seismic sources
Authors: Cabieces Roberto , Junqueira Thiago C. , Relinque Jesús
Published: March 2024

surfQuake is a new software designed to overcome the workflow process that involves the estimation of seismic source parameters. The complete set of toolboxes inside surfQuake allows the user the complete automation of seismic phases arrival times estimation and events association, event locations, magnitudes and attenuation, slowness vector, and moment tensor inversion.The software is programmed in Python 3 and offers the users the possibility of three programming levels. From the core library, which allows the user to integrate the core of surfQuake into his own scripts, to the Command Line Interface, which gives the user access to an upper layer that simplifies the use of the core. Finally, surfQuake core is wrapped by a Graphical User Interface (GUI) and connected to a SQL Lite database to store all the results. The user has direct access to query the database tables to extract important information through the object Relational Mapper SqlAlchemy directly managed from the GUI.The software has been fully tested with the earthquake cluster that occurred during the eruption of La Palma in 2021-22. The source parameters resulting from the eruption and the basic statistics associated with them are displayed using the database toolbox. Additionally, we offer a web tutorial with the documentation of surfQuake and a set of usage examples for the three programming levels.
Ecophysiological modelling of cessation of wood formation phenology in temperate and boreal forest trees
Authors: Lin Jianhong , Delpierre Nicolas , Rathgeber Cyrille
Published: March 2024

Wood phenology is an important indicator of ecosystem response to climate change. However, compared to leaf phenology, the understanding of wood phenology is still in its infancy. In this study, we developed the first ecophysiological model to simulate the cessation of wood formation for two major Northern Hemisphere conifer species (Pinus sylvestris and Picea abies). The model developed postulates cessation of wood formation to be driven by both photoperiod and temperature. We calibrated and validated the model based on the GLOBOXYLO database documenting the occurrence of phenological stages in wood formation. We focused on two European species here, namely Pinus sylvestris and Picea abies, totaling 96 site-years. The model received support for both species with a root mean square error of 12.6 days and 8.6 for the prediction of validation data, respectively. The model accuracy was significantly related to the within-population variability in the observed data of cessation of wood formation, with higher prediction errors in years when trees of the same population were not in sync. Moreover, we found the number of radial cell and tree diameter to also affect the cessation of wood formation based on a path analysis model. This study improves the knowledge of the role of environmental and ontogenetic factors controlling the cessation of wood formation in the temperate and boreal zones.
Multi-spacecraft observations of 10 December 2021 ICME impact on Mars
Authors: Yu Bingkun , Chi Yutian , Owens Mathew , Scott Christopher , Shen Chenglong , Xue Xianghui , Dou Xiankang , Heyner Daniel , Auster Hans-Ulrich , Richter Ingo , Sánchez-Cano Beatriz , Lockwood Mike , Wang Yuming
Published: March 2024

The Tianwen-1 spacecraft is China’s first Mars exploration mission, released by the China National Space Administration (CNSA). It was launched from the Wenchang Space Launch Center on Hainan Island on 2020 July 23 and entered into a Mars orbit on 2021 February 10. The Tianwen-1 payload consists of 13 instruments, seven of which are deployed on the orbiter and six of which are put on the Zhurong rover. A rapid ICME swept across Mars' space environment between 00:00 on December 10 and 20:00 on December 11. Multi-spacecraft observations from Tianwen-1, MAVEN, and BepiColombo are used to investigate the impact of the ICME on the Martian upper atmosphere and ionosphere.
Enhanced late spring ozone in southern China by early onset of the South China Sea summer monsoon
Authors: Zhang Xiaorui , Lu Xiao , Wang Fan , Zhou Wen , Wang Peng , Gao Meng
Published: March 2024

The onset of the South China Sea summer monsoon (SCSSM) profoundly impacts meteorological conditions over East Asia. However, whether the interannual variability in monsoon onset date impacts ozone (O3) pollution remains unclear. Here, we investigate the relationship between the early onset of SCSSM and late spring O3 in southern China. Our results show notable differences in surface O3 concentrations before and after SCSSM onset during early onset events in southern China. The enhanced O3 of 11.1 µg m-3 is supported by increased air temperature and solar radiation of 1.1 K and 30.9 W m-2 and reduced relative humidity of -5.7%. Both observation and model simulations confirm that O3-favorable meteorological conditions modulated by early SCSSM onset can be found in May. It increases the boundary layer height and biogenic emissions of volatile organic compounds, enhancing O3 by 10 µg m-3 over southern China. Chemical processes dominate such increases in O3 with enhanced chemical production of 0.27 Tg month-1. Descending motion in southern China vertically transports O3 to the surface by 0.10 Tg month-1, whereas horizontal advection reduces O3 concentration by 0.12 Tg month-1. The meteorological responses to colder sea surface temperature (SST) in the central equatorial Pacific are pronounced, leading to higher O3 concentrations over the Yangtze River Delta, while warmer SST in the Philippine Sea contributes O3 over the Pearl River Delta and eastern China. This study highlights the importance of SCSSM onset with respect to O3 in southern China, with promising applications in management of air pollution and agriculture.
Potential assessment of flood resource utilization based on the inflow flood identification model
Authors: Huang Jing , Tan Chao , Chen Xiaohong , Li Jiqing
Published: March 2024

The potential assessment of flood resource utilization is a prerequisite for the rational allocation of water resources and storage capacity in a watershed. In response to the increasingly uneven distribution of water resources in the context of climate change, an inflow flood identification model was established based on the Kolmogorov-Smirnov test, improved peak-over threshold method, and time-varying parameters with Poisson distribution model. A potential assessment method of flood resources utilization in reservoir groups was proposed based on constraints such as the comprehensive regulation and storage capacity of the watershed and water demand. The four cascaded reservoirs in the lower Jinsha River (Jinxia Four Reservoirs), namely Wudongde, Baihetan, Xiangjiaba, and Xiluodu, was used as a case study. The results show that: 1998 and 2002 are the consistency change points of the runoff seies from June to November at Xiangjiaba Hydrological Station. The main type of inflow flood is short-fat, and the 3-day flood volume is a key indicator of balanced comprehensive utilization benefits except for the flood peak. Jinxia Four Reservoirs are constrained by storage capacity, when encountering floods with a design standard of once-in-a-century or below, the potential utilization of flood resources is 37.27×108m3. It is recommended to continuously optimize the storage capacity by raising the water level to 952.26m, 806.77m, 576.31m, and 373.99m in sequence of Jinxia Four Reservoirs. This work aims to provide reference for the optimal allocation of water resources and storage capacity in the watershed.
Airborne Measurements of OH Reactivity over Urban Megacities
Authors: Stainsby Aaron ,   AEROMMA Team
Published: March 2024

           The production of organic peroxy radicals from the reactions of the hydroxyl radical (OH) and organic compounds is frequently a rate-limiting step in the formation of ground-level ozone.  OH reactivity, the inverse of the OH radical’s lifetime, gives a measure of the production rate of peroxy radicals. A custom-built instrument that can directly measure the total OH reactivity was developed at the Forschungszentrum Jülich and employed on the AEROMMA measurement campaign, organized by the US National Oceanic and Atmospheric Administration in the summer of 2023. The measurement campaign utilized a variety of aircraft and an array of advanced instrumentation to investigate the chemical composition of urban pollution outflows. It is expected that the importance of vehicle emissions is decreasing and that of other emissions, like volatile chemical products, are increasing.  OH reactivity was measured over major urban areas, including New York City, Los Angeles, Chicago, and Toronto.           A suite of instrumentation measured the OH reactants, such as inorganics, nitrogen oxides, alkanes/alkenes, aromatics, and biogenic organic compounds. In the presentation, the sum of OH reactivity from these species is compared to the measured reactivity, to explore the closure of reactivity budget.  From the measurement campaign, the relative contributions of different emission sources to the total OH reactivity including sources for VCPs are analyzed.
Expanding PlioVAR to PlioMioVAR: Updates and Future Directions
Authors: Ford Heather L. , Sosdian Sindia , McClymont Erin , Modestou Sevi , Ho Sze Ling , Burls Natalie , Dolan Aisling , Fletcher Tamara ,   PlioMioVAR
Published: March 2024

The Pliocene (~2.6-5.3 million years ago), and increasingly the Miocene (~23-5.3 million years ago), are used by the climate community as pseudo-analogs of future climate change. Relative to modern, the Plio-Miocene was globally warmer with reduced continental ice volume and reconstructed atmospheric carbon dioxide concentrations similar to or higher than present-day. The Past Global Changes (PAGES) PlioMioVAR working group expands on the previous PAGES PlioVAR working group aims to create a synthesis of marine and terrestrial data to characterise spatial and temporal reconstructions of Plio-Miocene climate. Major outputs from PlioVAR include a synthesis and evaluation of multi-proxy sea surface temperatures (SSTs) during the KM5c interglacial (~3.2 million years ago) and Pliocene-Pleistocene intensification of Northern Hemisphere Glaciation. In coordination with the Pliocene model intercomparison project Phase 3 (PlioMIP3), our Pliocene efforts are to 1) continuously update the existing mid-Pliocene database, 2) expanding our data synthesis to the early Pliocene (~4.5 and ~4.9 million years ago) and 3) synthesise terrestrial records. In coordination with the Miocene Model Intercomparison Project (MioMIP), our Miocene efforts are to 1) synthesise surface and deep temperatures and 2) identify Miocene time slices for data-model comparison. From workshop discussions, we’ve identified future research directions including 1) refining site-specific chronologies to ensure robust comparison of temperature records at short (i.e. glacial-interglacial) and longer time scales, 2) constraining seawater chemistry changes, 3) comparing multi-proxies with sufficient temporal and spatial coverage, and 4) reconstructing high-latitude regions (temperature and ice margin records) to improve our ability to to assess meridional temperature gradients, polar amplification, and ice sheet volume and stability. Focusing our efforts on these research directions could be community themes in the next incarnation of IODP. These databases and data-model comparisons are critical for navigating future climate change. This presentation outlines our current state of synthesis, assessment and analysis, and we welcome discussions on new data sets and approaches.
Deciphering Mars’ water cycle with missions and models
Authors: Franck Montmessin
Published: March 2024

My presentation will cover the present and recent configurations of Mars’ water cycle. The Martian water is only visible in two forms: gas and ice. The existence of a water cycle on Mars was deduced from the first seasonal monitoring of water vapor performed by the Viking mission in 1982. It revealed that the same seasonal and spatial pattern repeated itself for nearly two consecutive Martian years. After Viking, other missions have confirmed this initial conclusion: seasonal water vapor variations appear to be controlled by exchanges between various reservoirs, achieving an annual stationary state with some inter-annual differences. These variations are primarily influenced by the seasonal evolution of the climate in the north polar region, as the latter hosts the most massive reservoir of water, consisting of an ice cap of more than 2 million km3. When exposed to sunlight in spring and summer, this cap releases a massive amount of water vapor that then spreads across the Martian globe, only to return to the North Pole the following winter in the form of frost. Decades of theoretical and observational exploration have delivered a nearly comprehensive view of Mars’ water cycle. From the water molecules that leave the cap in summer to the hydrogen atoms that escape Martian gravity and get lost in space; I will show how the Mars missions and the 3D models used to simulate Mars’ climate have laid the foundations for our understanding of the main processes that govern the evolution of water on Mars.
Formate consumption and stable carbon isotope fractionation in anoxic rice field soils and lake sediments
Authors: Conrad Ralf , Claus Peter
Published: March 2024

Formate is energetically equivalent to hydrogen and thus, is an important intermediate during the breakdown of organic matter in anoxic rice field soils and lake sediments. Formate is a common substrate for methanogenesis, homoacetogenesis and sulfate reduction. However, how much these processes contribute to formate degradation and fractionate carbon stable isotopes is largely unknown. Therefore, we measured the conversion of formate to acetate, CH4 and CO2 and the δ13C of these compounds in samples of paddy soils from Vercelli (Italy) and the International Rice Research Institute (IRRI, the Philippines) and of sediments from the NE and SW basins of Lake Fuchskuhle (Germany). The samples were suspended in phosphate buffer (pH 7.0) both in the absence and presence of sulfate (gypsum) and of methyl fluoride (CH3F), an inhibitor of aceticlastic methanogenesis. In the paddy soils, formate was found to be an excellent substrate for acetate formation, while CH4 was mainly produced from acetate. Acetate was also produced in the presence of sulfate. The produced acetate was strongly depleted in 13C relative to formate (about -50‰ to-25‰), but the consumption of formate itself displayed only a small isotope enrichment factor on the order of -8‰ to -6‰. Therefore, it is likely that formate was disproportionated to 13C-depleted acetate and 13C-enriched CO2. The δ13C of CO2 was indeed slightly higher than that of formate. Acetate was most likely produced by homoacetogenesis via the Wood-Ljungdahl pathway. Methane was only a minor product and was mainly produced from the acetate as its production was inhibited by CH3F. The homoactogenic bacteria in the paddy soils apparently competed well with both methanogenic and sulfate-reducing microorganisms, when formate was the substrate. In the lake sediments, the product spectrum was similar, but only under methanogenic conditions. In the presence of sulfate, however, acetate and CH4 were only minor products and no enrichment factor was detectable when formate was degraded to mainly CO2. Hence, homoacetogenesis was the major anaerobic degradation pathway of formate. Formate-dependent methanogenesis was negligible, and sulfate-dependent oxidation was only operative in the lake sediments but not in the paddy soils.
The “NGGM-MAGIC: A breakthrough in the understanding of the dynamics of the Earth” project
Authors: Marotta Anna Maria , Barzaghi Riccardo , Braitenberg Carla , Brocca Luca , Cambiotti Gabriele , Camici Stefania , Casotto Stefano , De Gaetani Carlo Iapige , De Min Angelo , Fedi Maurizio , Pastorutti Alberto , Pivetta Tommaso , Reguzzoni Mirko , Riccardi Umberto , Rossi Lorenzo , Sabadini Roberto , Zoffoli Simona , Blasone Giovanni Paolo , Longo Francesco
Published: March 2024

The substantial improvement in spatio-temporal accuracy that will be provided by the ESA NGGM/MAGIC mission will make it possible to take a decisive step forward in our knowledge of the dynamics of the main physical processes involving the different compartments of the Earth.Since every physical process that occurs within each terrestrial compartment involves a redistribution of mass and therefore a signal of gravity, the project intends to provide results of impact and breakthroughs in the modeling and understanding of the dynamics of Solid Earth and Fluid Earth processes, the latter including the water stored in continents and oceans, as well as in geodesy.Methodologies will be developed that link gravity signals from the various compartments of the Earth to the MAGIC raw data, finally linking each terrestrial compartment with the two pairs of satellites, the core of MAGIC.The partnership proposing the project includes researchers from different Universities and Research Institutions and has all the skills in the various sectors mentioned above, from its assets in basic science to the application ones.The following activities are planned:- Modeling of the gravitational effects of slow tectonics and seismic cycle- Modeling of the gravitational effects from volcanic processes- Development of methodologies of compact imaging/inversion for the estimation of mass changes- Tidal and ocean circulation models for gravity signal and generation of L2 data- Precipitation and river flow models, hydrological models for the TWSA- High resolution background gravity and gravity anomaly error determination and E2E simulations for geophysical processes detectability.Among the objectives of these activities, common to all partners, there will be in particular that of verifying that the spatio-temporal resolution of MAGIC allows to satisfy the requirements necessary to extract from the mission data the gravity signal that allows a significant advance in the basic research and related applications in the various geophysical and geodetic components.The project is funded by the Italian Space Agency - ASI.
Chloride Trends in the Fox River watershed: Stratton Dam to Illinois River 
Authors: Getahun Elias , Zavelle Atticus
Published: March 2024

Applying road salt to melt ice on urban roads and pavements has raised the chloride levels in streams and rivers in the U.S. over time, which can damage aquatic life. High chloride levels in the waterbodies of the Fox River watershed, where one-third of the land is urban, are mainly caused by road salt application for deicing. This study analyzed how the chloride levels changed over the years and seasons in the Fox River watershed – from Stratton Dam to Illinois River. The Seasonal Kendall Tau (SKT) method was used to estimate the annual and seasonal trends in chloride concentration at 44 monitoring sites on the Fox River and its tributaries for three time periods (2017–2021, 2012–2021, and 1997–2021), after conducting exploratory data analysis and assessing the data suitability. The chloride concentration in the watershed varied over time, space, and season. From 2012 to 2021, it declined or remained stable at most of the monitoring sites, but it rose slightly from 1997 to 2021. The 5-year trend from 2017 to 2021 was similar, except that some sites showed an increase in summer and fall. The chloride concentration along the Fox River and Tyler Creek showed a longitudinal pattern, decreasing from upstream to downstream in most seasons and periods, except for the 5-year annual and fall trends, which increased. Weighted Regression on Time Discharge and Season (WRTDS) models were developed to estimate the trends in flow-normalized chloride flux for one site on the Fox River and two sites on its tributaries with daily flow data. The resulting trends indicate that the chloride fluxes dropped significantly at the Fox River and Polar Creek sites, mainly in the winter of 2012–2021. However, the site on Blackberry Creek had an opposite trend of increasing chloride flux, except for the winter flux, which also declined. Trends in selected streamflow statistics including mean, 7-day minimum, and 1-day maximum flows were also analyzed for the three monitoring sites to provide insight into how hydrologic variability affects chloride trends. The trends in annual and seasonal flow statistics exhibited a steep slope for low flows but a gradual slope for high flows, indicating more variability in the low flow statistics during the periods of analysis. The changes in chloride concentration and flux were partly related to the changes in flow, but other factors affecting water quality, such as watershed conservation, may also play a role. Assessing trends over distinct periods provides a nuanced understanding of how mitigation strategies may influence water quality improvements through the years and serves as a crucial guide for initiatives aimed at enhancing the overall health of the Fox River ecosystem. Choosing deicing methods that balance cost, performance, and environmental impacts should be a vital part of a mitigation plan. Moreover, monitoring and evaluating trends can help assess the current status of chloride levels in the watershed and inform future actions.
Long-term Solar Spectral Irradiance Observations by the TSIS-1 Spectral Irradiance Monitor
Authors: Richard Erik , Coddinton Odele , Harber Dave , Pilewskie Peter , Woods Tom
Published: March 2024

The NASA’s Total and Spectral Solar Irradiance Sensor (TSIS-1) launched on December 15th, 2017 and was integrated on the International Space Station (ISS) to measure long-term total solar irradiance (TSI) and solar spectral irradiance (SSI). The direct measurement of the SSI is made by the LASP Spectral Irradiance Monitor (SIM) and provides data essential to interpreting how the Earth system responds to solar spectral variability. Extensive advances in TSIS-1 SIM instrument design and new SI-traceable spectral irradiance calibration techniques have resulted in improved absolute accuracy with uncertainties of less than 0.5% over the continuous 200 to 2400 nm spectral range. Furthermore, improvements in the long-term spectral stability corrections provide lower trend uncertainties in SSI variability from those of the previous SORCE SSI instruments. We present the early mission results of the TSIS-1 SIM SSI observations for the first 5 years of operations – a time-period that includes the descending phase of solar cycle 24, the last solar minimum, and the ascending phase of solar cycle 25. Comparisons are made to previous spectral measurements both in the absolute scale of the solar spectrum and the time dependence of the SSI variability. The TSIS-1 SIM SSI spectrum shows lower IR irradiance (by as much as 6% near 2400 nm) and small visible irradiance increases (~0.5%) from the previous ATLAS3 and WHI reference solar spectra, but more consistent agreement with recent SCIAMACHY and SOLAR2 reanalysis results. We also show initial comparisons to current NRLSSI2 and SATIRE-S SSI model results both for short-term (solar rotation) spectral variability and, for the first time, the longer-term (near half solar cycle) spectral variability across the solar spectrum from the UV to the IR.
Introducing the first ecovoltaic parks of Hungary: a reconciliation between solar development and nature conservation
Authors: Tölgyesi Csaba , Magyar Botond , Frei Kata , Hábenczyus Alida Anna , Bátori Zoltán , Gallé Róbert
Published: March 2024

Solar energy is the most rapidly growing renewable globally. However, ground-mounted solar panels have a high land requirement, leading to extensive, low-nature-value photovoltaic parks. This may be alleviated by considering ecological aspects during their planning, construction and mainetnance. The resulting ecovoltaic park can bring various benefits for the owners if ecosystem services related to the imporved ecological conditions are recognized and wisely utilized. A major step in developing ecovoltaic parks is the creation of a short but species-rich grassland ecosystem. There is little empirical evidence on how to achieve this; therefore, we set up an experimental sowing experiment in three formerly conventional photovoltaic parks located in the forest-steppe zone of Hungary. From the regional native grassland species pool, we selected short but competitive ones (two graminoids and 50 forbs that are often visited by pollinators), and sowed them in half of the parks (between panel rows) in October, 2022, while the other half was left as control. In 2023, we surveyed the vegetation of the sown and control parts of the parks and adjacent old-growth grasslands (as references), and found that total plant species richness and the species richness of grassland specialists increased compared to the control sites, but remained below the references. In contrast, the cumulative cover of grassland specialist species in the sown sites could reach the references. We also surveyed pollinator assemblages (hoverflies and wild bees), and found higher species richness and Shannon diversity in the sown parts then in the reference grasslands, while control parts of the parks showed intermediate values. This might have been caused by spillover from the sown parts, although flying pollinators might have also taken advantage of the permanent windshade among the panel rows of control parts, despite the low food supply compared to the reference grasslands. Our findings suggest a rapid improvement of plant and pollinator assemblages after sowing native seed mixtures in solar parks. The resulting high-nature-value grassland ecosystem can have many co-benefits for the owners, as (i) it requires lower management intensity due to the short vegetation, (ii) has the potential to offer high-quality forage for livestock or honey-bees, and (iii) lowers the widespread “not-in-my-backyard” syndrome of local inhabitants due to its attractive, flower-rich appearance.
The linkage between autumn Barents-Kara sea ice and European cold winter extremes
Authors: Cai Di , Lohmann Gerrit , Chen Xianyao , Ionita Monica
Published: March 2024

While the Arctic's accelerated warming and sea ice decline have been associated with Eurasian cooling, debates persist between those attributing this to sea ice retreat and those to internal variability. Using the observational data to track month-to-month variabilities, we show that the variability of sea ice over the Barents-Kara Seas in autumn is related to extreme cold winters over much of the European continent. The winter temperature change in Europe is a direct response to a stationary Rossby wave generated by the lower troposphere diabatic heat anomaly as a result of sea ice loss over the Barents-Kara Seas in autumn, leading to a negative phase of North Atlantic Oscillation and more frequent episodes of the atmospheric blocking over Greenland and the North Atlantic. The negative phase of the North Atlantic Oscillation and enhanced blocking are closely related and mutually reinforcing, shaping the spatial distribution of cold anomalies over much of the European continent. Our results suggest a link between the unusual decrease in Barents-Kara Sea ice during autumn and the occurrence of intense European weather extremes in subsequent winter months. Delving deeper into this relationship on monthly time scales can enhance our predictive capabilities for midlatitude extreme events. 
A microfluidic approach to understanding coupled dissolution-precipitation during CO2 storage in fractured systems
Authors: Nisbet Haylea , Chen Michael , Neil Chelsea , Viswanathan Hari
Published: March 2024

Until recently, efforts to understand the fluid dynamics processes occurring in flowing fractures have generally excluded chemical reactions or only explored one reaction: dissolution or precipitation. This has hindered our progress in predicting the CO2 storage potential in a given system because it has limited our understanding of in situ carbon mineralization. Identifying the influence of fluid flow in fractures on geochemical reactions is particularly important for CO2 mineralization in low-permeability rocks, such as ultramafic rocks (e.g. peridotite), which will rely on fractures to act as primary conduits for CO2 distribution and mineralization. We are working towards bridging this knowledge gap by conducting experiments using an advanced high-P, high-T microfluidics setup that permits real-time visualization of carbon mineralization in a coupled dissolution-precipitation regime under flowing conditions.In order to understand fundamental regimes of coupled dissolution and precipitation relevant to mineral carbonation, experiments have been conducted in an analog setup where the dissolution of gypsum (CaSO4) by a carbonate solution is coupled to the precipitation of calcite (CaCO3). The fracture model used in the experiments included a primary channel and dead ends, which define advection and diffusion-dominated zones. We conducted experiments under different flow conditions, and the results revealed key factors that affect optimal carbonation. The amount, morphology, and geochemistry of carbonate mineralized was strongly influenced by the fluid flow rate. These results suggest that the rate of CO2 injection could be an important parameter to consider during in situ carbon mineralization operations.
The unsaturated soil hydraulic conductivity as a sum, an average, or a junction of domain conductivities
Authors: de Rooij Gerrit H.
Published: March 2024

Recent models of the unsaturated hydraulic conductivity curve (UHCC) are the sum of separate UHCCs for domains of capillary water, film water, and water vapor. A new theoretical framework for aggregating domain conductivities to a bulk soil UHCC reveals that this requires parallel domains. The same theory also generates arithmetic, harmonic, and geometric averages of the liquid-water conductivities, which can be arithmetically averaged with the vapor conductivity. However, current models for capillary and film conductivities are intrinsic, i.e., valid within their respective domain. The vapor conductivity is a bulk conductivity, i.e., it gives the conductivity of the gaseous domain as it manifests itself in the soil. Conversion relationships use the domain volume fractions as approximations of the as-yet unknown weighting factors to convert between intrinsic and bulk conductivities. This facilitates consistent averaging of domain conductivities. The fitted curves for the capillary and film water depend on the averaging (or adding) method. Hence, they are not strictly characteristic of their respective domains. Truly intrinsic domain conductivity functions may not exist, or are perhaps merely tools to arrive at a good fit of the UHCC of the bulk soil. Given these complications, a simpler junction model that joins a capillary and a film limb at a junction point offers an attractive alternative. 
The roles of flux-tube entropy and effective gravity in the inward plasma transport at Saturn
Authors: Wing Simon , Thomsen Michelle , Johnson Jay , Ma Xuanye , Mitchell Donald , Allen Robert , Delamere Peter
Published: March 2024

The inward plasma transport at Saturnian magnetosphere is examined using the flux tube interchange stability formalism developed by Southwood and Kivelson (1987).  Seven events are selected.  Three cases are considered: (1) the injected flux-tube and ambient plasmas are nonisotropic; (2) the injected flux-tube and ambient plasmas are isotropic and (3) the injected flux-tube plasma is isotropic but the ambient plasma is nonisotropic.  Case (1) may be relevant for fresh injections while case (3) may be relevant for old injections.  For cases (1) and (2), all but one events have negative stability condition, suggesting that the flux-tube should be moving inward.  For case (3), the injections located at L > 11 have negative stability condition, while 4 out of 5 of the injections at L < 9 have positive stability condition.  The positive stability condition for small L suggests that the injection may be near its equilibrium position and possibly oscillating thereabouts---hence the outward transport if the flux tube overshot the equilibrium position.  The flux-tube entropy plays an important role in braking the plasma inward transport.  When the stability condition is positive, it is because the entropy term, which is positive, counters and dominates the effective gravity term, which is negative for all the events.  The ambient plasma and drift out from adjacent injections can affect the stability and the inward motion of the injected flux tube. The results have implications to inward plasma transport in Jovian magnetosphere as well as other fast rotating planetary magnetospheres.