bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploring the horizon of geosciences through the lens of geoethics
Authors: Peppoloni Silvia , Di Capua Giuseppe
Published: March 2024

Geosciences play an indispensable role in the functioning of contemporary societies. Nevertheless, the technological aspects associated with the practical application of geoscientific knowledge, should not overshadow the fundamental contribution of geosciences to shaping human thought. Geosciences have not only influenced but continue to shape our perception of the world, its interrelationships, and evolution.The ongoing ecological crisis, with its environmental, social, cultural, economic, and geopolitical implications, has stemmed from an imprudent trajectory in human development. Regrettably, there have been instances where geosciences have contributed to this irresponsible path. This oversight has led to an undervaluation of the social and cultural significance inherent in geological disciplines and the crucial role they can play in addressing current global challenges to support human societies.Geoethics, as the ethics of responsibility towards the Earth system, is grounded in the comprehensive understanding provided by geoscientific knowledge of the complexity of reality. It stands out as the optimal tool for cultivating a new perspective on geosciences, recognizing them as fundamental disciplines crucial for addressing global environmental challenges. This recognition extends beyond technical considerations, emphasizing their cultural significance. By virtue of their epistemological foundations, the geosciences collectively represent an invaluable reservoir of knowledge for human civilization. They are indispensable for redefining the intricate relationship that binds us, as humans, to the Earth.For this reason, geoethical thought should serve as a complementary element to knowledge in the education of geoscientists. It aims to furnish them with a principled framework and ethical values, offering guidance for any application of geoscientific knowledge to the natural environment and human communities. Additionally, geoethical thought is the ground on which to set a shared, global ethical foundation, facilitating the advancement of our interactions with nature. It seeks to actualize an ecological humanism that forms the basis for human well-being and a more sustainable development of socio-ecological systems. The geoethical perspective redefines the cultural significance and objectives of the geosciences. Geoeducation and communication emerge as fundamental tools for bridging the gap between geosciences and society. They play a crucial role in promoting geoscientific knowledge, highlighting not only its scientific value in providing technical solutions to the ecological crisis but also emphasizing the philosophical dimension of geosciences, the geosophy of living consciously and responsibly within the Earth system.
Testing the Potential of Deep Learning in Earthquake Forecasting
Authors: Köhler Jonas , Li Wei , Faber Johannes , Rümpker Georg , Srivastava Nishtha
Published: March 2024

Reliable earthquake forecasting methods have long been sought after, and so the rise of modern data science techniques raises a new question: does deep learning have the potential to learn this pattern? In this study, we leverage the large amount of earthquakes reported via good seismic station coverage in the subduction zone of Japan.  We pose earthquake forecasting as a classification problem and train a Deep Learning Network to decide, whether a timeseries of length ≥ 2 years will end in an earthquake on the following day with magnitude ≥ 5 or not. Our method is based on spatiotemporal b value data, on which we train an autoencoder to learn the normal seismic behaviour. We then take the pixel by pixel reconstruction error as input for a Convolutional Dilated Network classifier, whose model output could serve for earthquake forecasting. We develop a special progressive training method for this model to mimic real life use. The trained network is then evaluated over the actual dataseries of Japan from 2002 to 2020 to simulate a real life application scenario. The overall accuracy of the model is 72.3%. The accuracy of this classification is significantly above the baseline and can likely be improved with more data in the future.
A Systems based approach to understanding the role of co-benefits in encouraging urban air quality interventions 
Authors: Cowell Nicole , Kirk Aoife , Okello Gabriel , O'Sullivan Natasha , de Nazelle Audrey , Weller Roderick
Published: March 2024

There is untapped potential in urban planning behaviour change policies that can simultaneously improve air quality, support net-zero targets, and benefit communities and public and planetary health more broadly. There is evidence  siloed thinking restricts the policy making process in optimising air quality interventions for co-beneficial outcomes. Systems-based approaches create holistic insights and solutions which can address  complex cross-cutting issues by bringing together context-specific evidence, an array of expertise and perspectives whilst merging social and environmental sciences to engage in action. Horizon scanning academic and non-academic literature can  generate insight into the current state of play of air quality interventions, their related outcomes and co-benefits including pathways to healthier cities. It also allows  insight into the gaps between science and policy for an evaluation of how to  generate science-to-policy discussions.  Structured decision-making is a systems approach in which stakeholders are engaged throughout a decision-making process to identify and co-create shared objectives and values around a complex issue, such as urban air quality. This work brings together systems-based approaches to assess the state of play and optimal next steps for addressing urban air quality, investigating the role that co-benefits could play in inciting ambitious change for sustainable cities. The poster will present initial findings from horizon scanning air quality interventions, co-benefits and pathways to healthy cities, which will inform the next steps of generating a structured decision-making tool for assessing the opportunities and challenges of co-created and co-beneficial actions for air quality change.This work is carried out in collaboration with the World Economic Forum Global Future Council on the Future of Clean Air, where academics and stakeholders are working together to address air pollution globally.  
Reconstructing the Late Holocene paleoclimate and paleoenvironmental changes in Southeastern Anatolia (Gölbaşı, Adıyaman, SE Türkiye) through fossil pollen and non-pollen palynomorphs (NPP) 
Authors: Gökgöz Dila Doğa , Biltekin Demet , Eriş Kürşad Kadir , Uçarkuş Gülsen , Kırkan Erdem , Bozyiğit Yakupoğlu Cerennaz , Acar Dursun
Published: March 2024

Fossil pollen and non-pollen palynomorphs are useful indicators to reconstruct paleoclimate and paleoenvironmental changes. In palynological investigations, evaluating the difference between anthropogenic effects and paleoclimatic conditions is important for understanding the causes of paleoecological changes during the Holocene. Non-pollen palynomorphs can be observed in pollen slides owing to their acid-resistant organic structure, providing complementary insights into erosion, pastoralism, cultivation, and trophic state in wetlands.This study investigates paleoclimate and paleoenvironmental variations in the Gölbaşı Basin, located in the East Anatolian Fault Zone (EAFZ), through palynological analyses that have been done on two sediment cores taken from Lakes Gölbaşı and Azaplı for the first time. The GLB-01 core, obtained from Lake Gölbaşı and dating back to 1995 +/- 35 cal BP, measures 129 cm in length and is predominantly composed of uniform, laminated reddish-brown mud. In comparison, the AZP-03 sediment core from Lake Azaplı spans 138 cm, with laminated green mud observed from the core's surface down to 96 cm depth. At the lowermost level of the AZP-03 core, peat deposits are present, containing gastropod shells (Gyraulus sp.) and wood remains attributed to Quercus bratii/libani, along with sandy detrital inputs. The top of the peat deposit dates back to 2889 +/- 27 cal BP. According to this study, cultivated trees are identified by Juglans, Pistacia, and Olea europea, while anthropogenic plants are represented by Caryophyllaceae, Amaranthaceae, Sanguisorba minor type, Centaura, Polygonum, and Plantago. Alongside the analysis of pollen grains, 39 sediment samples have been examined for Non-Pollen Palynomorphs (NPPs) at various percentages along the sediment cores. Notably, green algae Pediastrum, free-floating green algae Spirogyra, and the filter feeder Bosmina sp. exhibit high proportions within the initial 30 cm of the cores. Furthermore, Glomus, a mycorrhizal fungus linked to soil erosion, increases in abundance where herbaceous pollens are prevalent. Herbaceous plants, characterized by non-woody stems, may not provide the same level of soil protection as trees. In the absence of a dense tree canopy, herbaceous plants may be less effective in preventing soil erosion. The increase in Glomus in the cores could be indicative of a response to the changing soil conditions resulting from erosion. This study is supported by the ITU- Scientific Research Projects Coordination Unit (Project Number: MYL-2022- 43676) and TÜBİTAK Project (Grant Number: 121Y287). 
Methane a sign of life - what drives its dynamics on Mars?
Authors: Finster Kai , Begnhøj Mikkel , Nørnberg Per , Knack Jensen Svend , Thøgersen Jan
Published: March 2024

The dominant source of methane (CH4) on Earth is biological and thus a sign of life. Therefore, the discovery of CH4 in the Martian atmosphere was sensational and attracted a lot of attention both within the science community and in the public. Since its discovery, we have learned that the concentration of CH4 on Mars is very dynamic and follows an annual cycle with relatively high concentration during Martian summer and low concentration during winter. Until now the drivers behind this dynamic pattern remain enigmatic as photochemistry which stands behind most atmospheric processes on Mars is too slow to explain the rapid decline. We studied wind-driven erosion as known from dust-devils and/or sand storms and explored whether it can work as a rapid CH4 sink. The outcome of this study will be reported in my presentation. 
Understanding a complex ecosystem: Tillandsiales in the hyperarid core of the Chilean Atacama Desert
Authors: Koch Marcus , Stein Eric , Quandt Dietmar
Published: March 2024

Tillandsia landbeckii is a “core species” in the hyper arid parts of the Atacama Desert colonized by few vascular plants only and this species is totally depending on fog occurrence as the most important source of water. Tillandsia landbeckii is a key element of the most prominent vegetation type of the hyperarid Chilean Atacama core. Epiarenic growth, growing on bare sand and lacking any root system, evolved five times independently in the genus Tillandsia during the past 5 my in the Peruvian-Chilean Desert system and lay the ground to build up unique ecosystems, with Tillandsia purpurea representing the Peruvian vicariant species. The onset of this parallel evolution may be considered as a temporal land-mark for the evolution of those fog-dependent ecosystems of the hyperarid core Atacama. Footprints of evolutionary diversification of present-day gene pools of T. landbeckii go back roughly 500,000 years, and present-day biogeographic distribution pattern is mostly shaped due to environmental changes since the last 22,000 years and the Last Glacial Maximum (LGM). The genetic set-up is surprisingly characterized by ancestral gene pools, “frozen” hybrid genotypes and clonal propagation and dispersal. This observation feeds into our hypothesis that phenotypic plasticity - contributing to plant fitness and survival in space and time - is limited on individual level, but a genetic mosaic on population- and landscape level is compensating this by a mixture of different “frozen” geno- and phenotypes, thereby allowing to cope rapidly with environmental change at the extreme limits of plants´ life. A multi-disciplinary approach combining evidence from different disciplines (plant biology, evolutionary biology, microbiology, climatology, geology, geomorphology and remote sensing technology) aims to unravel the complex interplay of biotic and abiotic factors to elaborate on our understanding of life occuring at the limits of growth due to the lack of water. We introduce the complex phylogeographic history of the species in Chile and introduce a mechanistic/biological growth model exploring environmental - biotic and abiotic - parameters. For comparative analysis on metapopulation level three regions have been selected in Chile (North near Arica, Centre near Iquique, South near Caldera) for detailed comparative in-situ and ex-sito analyses. 
Deep winter mixed layer anchored by the meandering Antarctic Circumpolar Current: Cross-basin variations
Authors: Song Zihan , Xie Shang-Ping , Xu Lixiao , Zheng Xiao-Tong , Lin Xiaopei , Geng Yu-Fan
Published: March 2024

The Southern Ocean features some of the deepest winter mixed layers on Earth, crucial for water mass formation and the storage of anthropogenic heat. The winter mixed layer depth (MLD) significantly varies across basins, exceeding 300 m in the Indian and Pacific sectors but less than 150 m in the Atlantic. Current climate models simulate a distribution that is too broad and struggle to accurately represent this inter-basin variation. Using observational data and a global atmospheric model, this study investigates the contribution of surface buoyancy flux and background stratification to inter-basin MLD variations.The surface heat flux is decomposed into broad-scale and frontal-scale variations, both of which are influenced by the Antarctic Circumpolar Current’s (ACC) structure. At the broad-scale, the meandering ACC path is accompanied by a zonal wavenumber-1 structure of sea surface temperature with a warmer Pacific than Atlantic; under the prevailing westerly winds, this temperature contrast results in larger surface heat loss facilitating deeper MLD in the Indian and Pacific than the Atlantic. At the frontal-scale, intensified ACC fronts in the Indian sector further strengthen heat loss to the north. Surface freshwater flux pattern largely follows that of evaporation and reinforces the heat flux pattern, especially in the southeast Pacific.Background stratification also significantly varies across the Southern Ocean, influencing MLD pattern. In the Atlantic and western Indian oceans where the ACC is at a low latitude (45°S), solar heating, intrusions of subtropical gyres and energetic mesoscale eddies together maintain strong stratification. In the southeast Pacific, in comparison, the ACC reaches its southernmost latitude (56°S), far away from the Subtropical Front. This creates a weaker stratification that allows deep mixed layers to form.
A systematic analysis at stations of the Italian seismic network to test the role of local topographic effect.
Authors: Ariano Mario , Fantozzi Pier Lorenzo , Albarello Dario
Published: March 2024

The Italian seismic code (NTC18) provides indications about the expected effects of some morphological configurations on the expected ground motion during earthquakes. In particular, two main 2D morphologies are identified as reference: cliffs and crests. Based on numerical simulations, the value of St is assumed to depend on the steepness of the cliffs and aspect ratio of the crest. A critical aspect of these estimates is that the considered configurations are defined in terms of steepness angles and aspect ratios, without any scale indication. Moreover, the considered morphologies are very schematic, and this prevents their simple application in the natural context: in most case an expert judgement is necessary, and this makes the final estimates potentially controversial and difficult to validate on the basis of empirical observations. To face this problem, in the frame of the PRIN project “SERENA”, a procedure has been developed for the automatic identification of areas prone to morphological amplification effects by following NTC18 prescriptions,  based on the Digital Terrain Model. The proposed approach allows the full exploitation of topographical data at the maximum resolution available. After a first application to restricted areas, the proposed procedure has been applied at National scale at the seismometric and accelerometric sites managed by INGV. The aim is twofold: first comparing outcomes of the new approach with the ones proposed by other Authors at the same sites, second to provide a sound basis of a coherent and reproducible estimate of St values to be compared with possible empirical evidence. In the presentation, the results obtained about the first aim will be presented and discussed.
Numerical simulation of IL-8-based relative inflammation potentials of aerosol particles from vehicle exhaust and non-exhaust emission sources in Japan
Authors: Kajino Mizuo , Kayaba Satoko , Ishihara Yasuhiro , Iwamoto Yoko , Okuda Tomoaki , Okochi Hiroshi
Published: March 2024

Spatial distributions of interleukin-8 (IL-8)-based relative inflammation potentials (IP) of PM2.5 from vehicle exhaust and non-exhaust emission sources in Japan are derived using the meteorology–chemistry model (NHM-Chem) and laboratory experiments. In this study, IP is first defined as multiplying PM2.5 from different emission sectors by supernatant IL-8 concentrations released using PM2.5 samples, normalized to that of particle-free controls. The simulated IP of primary exhaust particles IP(E) accounts for 3%–30% of the total vehicle IP (exhaust + non-exhaust, primary + secondary), IP(V), which is low in densely populated regions (3%–15%) and high (5%–30%) in less populated regions, because there are fewer exhaust PM2.5 emitters (diesel trucks) in more populated regions. The contribution of IP(V) to IP of the total environmental PM2.5, IP(A), varied substantially in space by approximately 3–5 times (the contributions are greater in larger cities as there is more traffic). In our estimates, IP(V) is approximately one and two orders of magnitude higher than IP(E) and IP(T), the IP of fresh tire wear particles (TWPs), respectively. IP(T) has a minor contribution to IP(V) and IP(A). Recently, however, aged TWPs have been reported to be toxic; thus, the aging process of TWPs needs to be considered in the future.
Identification of long-term irrigation effect on plant water use from geophysical and proximal sensing observations: example of a vineyard
Authors: Peruzzo Luca , Mary Benjamin , Burchard Levine Vicente , Guerra Jose , Herrezuelo Miguel , Lovera Raul , Casas Albert , Cassiani Giorgio , Nieto Hector , Pena José
Published: March 2024

This study investigated the influence of long-term irrigation management on plant water use with an emphasis on the development and activity of grapevine root systems in an irrigated vineyard under semi-arid conditions located in the Madrid region (central Spain). The study tested three types of irrigation management, based on the potential evapotranspiration ETp computed with varying crop coefficient Kc (0.2KC, under-irrigated. 0.4KC, control and 0.8KC, over-irrigated). Note that the irrigation water used is considered as highly saline (3890 μS/cm at 20°C).The interpretation was supported by soil geophysical surveys with electrical resistivity Tomography (ERT), plant physiological traits, and drone-based remote sensing observations. The ERT collected before irrigation showed strong evidence of soil long-term changes, with a gradient of electrical resistivity (ER) increasing with the stress applied, while time lapse ERT before/after the irrigation season showed changes implying deeper root contribution to water uptake in the stressed area. However, uncertainties persisted in interpreting higher ER areas, as it was unclear whether they stemmed from increased soil moisture or were linked to soil salinity caused by soil sodicity.Insights could be derived from proximal and remote sensing data, revealing patterns consistent with soil responses to the applied irrigation stress. Notably, the higher Normalized Difference Vegetation Index (NDVI), thermal-based actual evapotranspiration rates and stomatal conductance (gs) observed in the over-irrigated area, in contrast to the under-irrigated area, may suggest enhanced plant water accessibility and increased transpiration rates. The study paves the way towards the adoption of geophysical methods in combination with remote sensing to control irrigation management particularly in the context of saline water.
A Significant Mode of Small, Tropospheric Particles in the Lower Stratosphere
Authors: Brock Charles , Lyu Ming , Ahern Adam , Schill Gregory , Lawler Michael , Abou-Ghanem Maya , Murphy Daniel , Gurganus Colin , Thornberry Troy , Moore Fred , Hintsa Eric , Hall Bradley , Dutton Geoff
Published: March 2024

The stratospheric aerosol layer plays an essential role in stratospheric chemical and radiative processes. Emissions of SO2 from small-to-midsized volcanic eruptions are typically introduced into the lower stratosphere, where a background aerosol already exists. The radiative and chemical consequences of these eruptive emissions depend in part upon the characteristics of these background particles, whose number originates from the troposphere. In-situ observations of sub-0.1 µm diameter particles in the upper troposphere/lower stratosphere are rare, but are of particular importance in understanding the contribution of upwelling ultrafine particles formed near the tropical tropopause and their subsequent evolution in the stratospheric (Brewer-Dobson) circulation.In the  Stratospheric Aerosol processes, Budget and Radiative Effects (SABRE) mission from January to March 2023, we used three particle sizing instruments on the NASA WB-57 high-altitude aircraft to measure the size distribution of aerosol particles in the size range from 0.003 to ~4.0 μm in the lower stratosphere from middle to high latitudes at altitudes up to 19.6 km. The composition of individual aerosol particles >0.1 µm was also measured, along with O3, N2O, SF6 and OCS. Together, these measurements were used to investigate dynamical and chemical processes in the stratosphere that determine the evolution of the stratospheric aerosol as a function of stratospheric age up to several years. We observed a clear bimodal size distribution structure, with a small mode (< 0.1 μm diameter) originating from the troposphere and a larger mode (>0.2 µm diameter) originating from the photolysis of OCS (the classic Junge, or stratospheric, aerosol layer). These two modes evolve as a function of stratospheric age in a manner consistent with coagulation, condensation, and sedimentation. These are the first reported observations of the presence and evolution of this bimodal aerosol structure deep into the stratosphere. The small (tropospheric) particle mode provides a significant condensation sink at young stratospheric ages. SO2 from modest volcanic eruptions emitted into the lower stratosphere may condense on these smaller particles, reducing the amount of light scattering per unit mass. Proposed geoengineering efforts must also account for this tropospheric mode of particles. Models simulating aerosol processes in the stratosphere need to accurately represent tropospheric particles in the lower stratosphere and their evolution with stratospheric age.
Transport Mechanisms of Microfibers and Their Effects on Soil-Plant Systems
Authors: Chen Zhangling , Banwart Steven.A , Kay Paul , Pramanik Devlina Das , Ashley David , Feng Weiyi , Nash Thomas
Published: March 2024

Microplastics (MPs) have emerged as a global environmental concern due to the uncertainties surrounding their occurrence, fate, and potential implications for environmental and human health. While research on the impact of MPs on aquatic systems is expanding, studies investigating their influence on terrestrial systems are limited. Agricultural soil acts as a dominant reservoir for MPs, with microfibers being a predominant form due to the application of organic amendments. Despite their ubiquity, the transport mechanisms of these particles and their effects on soil-plant systems remain largely unknown. This study addresses critical knowledge gaps by conducting a series of soil incubation experiments aimed at exploring the effects of polyester (PES) microfibers on soil quality and the growth of three common crops: lettuce, Chinese cabbage, and radish. Plants were cultivated in glass jars containing 100mg/kg fluorescent microfibers thoroughly mixed with the soil. Microfiber distribution was visualized using EVOS Auto FL 2. Soil endpoints revealed that the presence of microfibers induced significant alterations in soil bulk density, with minimal impact on soil carbon and nitrogen content across all plant treatments. Additionally, microfibers exerted a significant decrease in soil pH in lettuce-growing soil, while exhibiting a marginal pH increase in cabbage-growing and radish-growing soils. Microfibers were also found to diminish the formation of water-stable aggregates, particularly in the cabbage-growing soil. In terms of plant endpoints, the study observed accelerated germination of lettuce in the presence of microfibers, while the root length of radish was substantially affected. Microfibers led to a reduction in chlorophyll content in lettuce and cabbage leaves, whereas radish leaves exhibited an increase when exposed to microfibers. Microfibers were detected in both lettuce and radish roots and stems, and weak fluorescence was detected in lettuce leaves. Notably, the impact of microfibers varied among plant species, emphasizing the necessity for species-specific considerations. Furthermore, this study highlights the negative, positive, and neutral effects of microfibers on soil properties and plant performance and proves the potential uptake of microfibers by certain edible plants. The observed outcomes are attributed to the distinctive characteristics of fibers, including their unique shape, surface area, and flexibility, which may interact with soil particles and crops. Given the widespread distribution and accumulation of microfibers in agricultural soil, this study provides crucial insights for ecotoxicological assessments related to soil and terrestrial higher plants. It also holds implications for stakeholders in environmental pollution, food safety, and human health.
Magnitude and intensity simulation of ground motion on near-fault areas: the case of Talysh (southern Azerbaijan)
Authors: Babayev Gulam , Aliyev Yashar , Aliyev Mirzali
Published: March 2024

In this research, we combine seismic and tectonic approaches in an attempt to apply the empirical relationships between fault parameters and earthquake magnitudes aiming to assess the maximum possible magnitude for the prediction of intensity ground motion in the areas close to active faults. The case we study is the Talysh area in southern Azerbaijan with the total area of 3960 km². It stretches to 38054'N northern latitude and 48035'E eastern longitude and spreads to the north through the Alborz mountains of Iran. The earthquakes with a higher depth are concentrated mainly in the central part of the Talysh zone (up to 70 km) and in the southwestern part of the Caspian Sea (up to 55 km), with the local magnitude range of up to M5.5.The earthquake magnitudes calculated on the basis of the surface fault length were compared with the catalogued magnitudes. As a procedure, (1) a comprehensive catalogue of all available known faults was compiled; (2) earthquake magnitude is then derived from fault length; (3) the resulting fault-length-earthquake-magnitudes were compared by the mathematical difference with catalogued earthquake magnitudes; and (4) as a final, intensity simulation of ground motion on near-fault areas was plotted. The results show the approximate consistence of the calculated fault-length-earthquake-magnitude with the catalogued seismicity. The map shows that the highest intensity areas of VII are observed in the central and western parts of the zone. An intensity VI covers majority of the Talysh zone. The results will contribute to the implementing more solid analyses for advancing seismic hazard analysis. Our research emphasizes the seismotectonic areas in southern Azerbaijan where further comprehensive studies on faults are required.
Properties and baroclinic instability of stratified thermal ocean flow
Authors: Beron-Vera Francisco
Published: March 2024

We investigate the properties of, and can carry out a stability analysis of a baroclinic current in, a stratified thermal rotating shallow-water model for the subinertial dynamics of the upper ocean, a key player in the global climate system where most of the ocean variability is concentrated affecting the lateral transport of floating material such as plastic garbage, oil, and Sargassum seaweed.  Unlike the standard thermal model, the model considered here includes linear buoyancy variation in the vertical, still maintaining its two-dimensional structure and that of the adabatic (constant density) model.  Like the standard thermal model, the stratified thermal model produces submesoscale circulations resembling those observed in satellite imagery, yet taking longer to manifest.  Our study is motivated by this numerical observation. The model possesses a Lie--Poisson Hamiltonian structure.  A particular aspect of the model is that it supports motion integrals which neither form the kernel of the corresponding bracket nor are related to any explicit symmetries via Noether's theorem.  Among other things, we investigate the role of these conservation laws in constraining the growth of finite-amplitude perturbations to a zonal flow with quadratic vertical shear. Joint work with Maria J. Olascoaga.
The effects of ice nucleation parameterizations in GFDL climate model 
Authors: Guo Huan , Fan Songmiao
Published: March 2024

We incorporated a temperature, dust, and sea spray aerosol-dependent ice nucleation parameterization in the recently developed GFDL AM4-MG2 framework, and refer to this new configuration as AM4-MG2-new. The major difference of the ice nucleation parameterizations in AM4-MG2-new and AM4-MG2 is the inclusion of sea spray aerosol as ice nucleating particles (INPs). Then we conducted AMIP (Atmospheric Model Intercomparison Project) mode simulation with AM4-MG2-new. It turns out that AM4-MG2-new produces mean model climate comparable to AM4-MG2, for example, similar cloud radiative and precipitation fields, but different cloud water phase partitioning or supercooled cloud fractions, especially over the mid-high latitudes where mixed-phase clouds (clouds that consist of both liquid and ice) are prevalent. The cloud-phase feedback could in turn impact the estimate of climate sensitivity. The results suggest that ice nucleation parameterizations, which have large uncertainties, have important impacts on climate sensitivity.
Non-conservative nature of Boron in low salinity Arctic ice and ice melt zones
Authors: Rush Samantha , Lee Chang-Ho , Lee Kitack , Vlahos Penny , Barrett Lauren
Published: March 2024

The Arctic Ocean is one of the most rapidly changing environments on the planet as sea ice extent and thickness have declined extensively over the last 40 years. It is predicted that by 2050, Arctic summers will become mostly ice-free, and the Arctic Ocean will be dominated by seasonally annual, rather than multiyear, sea ice. Arctic sea ice serves as a mediator of biogeochemical processes globally, though the impacts of increased ice melt and water column freshening on Arctic biogeochemistry are uncertain. Specifically, declining sea ice raises significant concerns regarding the future carbon uptake potential of the Arctic and the buffering capacity, or alkalinity, of seawater. Boron (B) is a major element in seawater, and in the form of the borate ion, it serves as the third largest contributor to alkalinity. Boron concentrations in the open ocean are typically conservative and accounted for through relationships with other water components, such as with salinity (S) in the boron to salinity ratio (B/S). Well established B/S ratios have been defined for the open ocean; however, salinity variability can create discrepancies in the open ocean boron corrections for alkalinity. In 2021, work in the marginal ice zone of the Bering and Chukchi Seas revealed non-conservative boron behavior and significant alkalinity system inaccuracies based on the deviation in computed B/S ratios in ice cores and brine. In this study, we investigate the B/S ratio in ice melt zone waters, snow, brine, annual, and multiyear sea ice from the eastern Arctic basin. A total of 169 samples were collected during the onset on melt (May-June 2023) on the ARTofMELT expedition across a range of salinities (2 - 63). High salinity samples (S>29) included 1 lead, 7 brine, 16 under-ice, and 28 open ocean water samples. Low salinity samples (S
The influences of sedimentary environments on carbon accumulation in lacustrine deposits: Evidences from elemental geochemistry
Authors: Zhang Mingming
Published: March 2024

The carbon dynamics of lacustrine deposits play an important role in controlling the atmospheric carbon cycle. However, the influences of various sedimentary factors on carbon accumulation in lacustrine deposits are rarely known. In this study, the petrological and geochemistry analyses of organic-rich (average total organic content = 24.22 wt.%) lacustrine deposits and organic-poor (average total organic content = 2.48 wt.%) lacustrine deposits buried under a peatland (the Zhibian peatland) in Northeast Asia are used to explore the above issues. Results suggest that the concentrations of major oxides, trace elements and rare earth elements in the organic-poor lacustrine deposits are higher than those in the organic-rich lacustrine deposits. Furthermore, these lacustrine deposits were sourced from felsic rocks. The tectonic background was continental island arc and active continental margin. Additionally, the sedimentary models of lacustrine deposits buried under peat sequence were also concluded. Organic-poor lacustrine deposits were developed in a deep-water area, that was freshwater and oxygenic condition. This type of lacustrine deposit was influenced by the frequent input of coarse-grained terrigenous debris and low productivity. In contrast, the organic-rich lacustrine deposits were developed in a shallow-water area, that was saline and anaerobic condition. This type of lacustrine deposit was influenced by a rare input of fine-grained terrigenous debris and high productivity. These findings should assist future studies on the carbon dynamics of buried lacustrine deposits. This study would provide a representative example of carbon accumulation processes and mechanisms in buried paleolake system in Northeast China.
Enhancing GRACE-FO Gravity Field Solutions: A Comparative Assessment and Novel Combination of ACT Products
Authors: Nie Yufeng , Chen Jianli , Shen Yunzhong , Chen Qiujie
Published: March 2024

The performance degradation of one onboard accelerometer of the GRACE-FO mission presents a significant challenge to the scientific community. This issue has been largely mitigated by transplanting data from the other fully functional accelerometer. Various accelerometer data transplant (ACT) products have been developed using distinct methodologies, each showing different performances in gravity field recovery. In this study, we conduct a systematic evaluation of three available ACT products—JPL-ACT and JPL-ACH from NASA's Jet Propulsion Laboratory, and TUG-ACT from Graz University of Technology—utilizing a uniform Level-1B data processing approach. Our analysis reveals that these ACT products exhibit inconsistent quality across different time periods. Consequently, we introduce a novel approach combining these ACT products at the normal equation level to enhance gravity field solution accuracy. Compared to solutions using the JPL-ACT, the combined solution gives a notable noise reduction of 5% to 12% depending on the choice of post-processing filters and the replacement of C20/C30 coefficients, which doubles the noise reduction achieved by the next best individual ACT product, JPL-ACH. Furthermore, the C20 coefficient derived from the combined solution agrees better with the Satellite Laser Ranging (SLR) benchmark, compared to those derived from individual ACT products. This advancement largely reduces the spurious 161-day signal observed in polar regions. Regarding the C30 coefficient, while JPL-ACT solutions exhibit suboptimal estimates, the JPL-ACH, TUG-ACT, and combined solutions all contribute to substantial improvements.
Nitrite stimulates HONO and NOx but not N2O emissions in Chinese agricultural soils during nitrification
Authors: Wu Dianming , Song Yaqi , Yu Yuanchun , Dörsch Peter
Published: March 2024

The long-lived greenhouse gas nitrous oxide (N2O) and short-lived reactive nitrogen (Nr) gases such as ammonia (NH3), nitrous acid (HONO), and nitrogen oxides (NOx) are produced and emitted from fertilized soils and play a critical role for climate warming and air quality. However, only few studies have quantified the production and emission potentials for long- and short-lived gaseous nitrogen (N) species simultaneously in agricultural soils. To link the gaseous N species to intermediate N compounds [ammonium (NH4+), hydroxylamine (NH2OH), and nitrite (NO2‒)] and estimate their temperature change potential, ex-situ dry-out experiments were conducted with three Chinese agricultural soils. We found that HONO and NOx (NO + NO2) emissions mainly depend on NO2‒, while NH3 and N2O emissions are stimulated by NH4+ and NH2OH, respectively. Addition of 3,4-dimethylpyrazole phosphate (DMPP) and acetylene significantly reduced HONO and NOx emissions, while NH3 emissions were significantly enhanced in an alkaline Fluvo-aquic soil. These results suggest that ammonia-oxidizing bacteria (AOB) and complete ammonia-oxidizing bacteria (comammox Nitrospira) dominate HONO and NOx emissions in the alkaline Fluvo-aquic soil, while ammonia-oxidizing archaea (AOA) are the main source in the acidic Mollisol. DMPP effectively mitigated the warming effect in the Fluvo-aquic soil and the Ultisol. In conclusion, our findings highlight the important role of NO2‒ in stimulating HONO and NOx emissions from dryland agricultural soils. In addition, subtle differences of soil NH3, N2O, HONO, and NOx emissions indicated different N turnover processes, and should be considered in biogeochemical and atmospheric chemistry models.
Fluvial and coastal sedimentary response to extreme fluctuations in rainfall, central California, USA
Authors: East Amy , Stevens Andrew , Snyder Alexander , Ritchie Andrew , Dow Helen , Warrick Jonathan
Published: March 2024

Understanding landscape response to changing climate is essential to protecting lives, property, and infrastructure. In some regions, climate warming is associated with enhanced fluctuations between wet and dry hydrologic extremes; such hydroclimatic ‘whiplash’ has been evident in California, USA, over the past decade. We studied sedimentary responses to these changes on the central California coast, focusing on the 357-km2 San Lorenzo River watershed and its nearshore zone. This study used fluvial suspended-sediment data together with biannual topographic and bathymetric coastal surveys to quantify the magnitudes and time scales of extreme-event signals. We find that in two extreme wet years (2017 and 2023), fluvial sediment loads were an order of magnitude greater than in years with average rainfall and nearly three orders of magnitude greater than during extreme drought. Extreme wet years are associated with substantial accretion in the nearshore zone around the river mouth, totaling several hundred thousand tonnes of new sediment in 2017 and 2023. The signal of aggradation can persist along the coast for 3–4 years. In wet years with multiple river floods, the floods occurring later in the wet season supply disproportionately coarse suspended sediment to the coast (60–75% sand), indicating their outsized importance on littoral sediment budgets as beach-building events. The dominance of coarse fluvial sediment after unusually large seasonal rainfall is attributable to landslides supplying coarse material to stream channels. In contrast, river floods occurring earlier in the wet season or in non-extreme-wet years supply finer-grained suspended sediment (20–30% sand, attributed to less landslide activity under drier antecedent soil conditions) and thus are less likely to influence coastal morphology. Understanding these process changes will be important for effective management of fluvial and coastal systems under a future, warmer climate with greater risk of both drought and extreme rain.
Quantitative Sn-wave Attenuation Beneath the Tibetan Plateau and Lithospheric Rheology
Authors: Zhao Lian-Feng , Xie Xiao-Bi , He Xi , Yao Zhen-Xing
Published: March 2024

Sn wave, a regional seismic phase, propagates horizontally in the uppermost mantle and is sensitive to lateral variations in mantle lid thickness, temperature, and melt. The physical properties of the lithosphere can be indicated by Sn propagation efficiency or attenuation. The inefficient Sn propagation has been typically used to describe the regions with high-temperature anomalies in the uppermost mantle and infer the subduction front of the Indian lithosphere in the north Tibetan plateau. Here we collect 122,481 tangential-component digital seismograms, isolate the geometric spreading and attenuation for SH-type Sn wave, and construct a broadband uppermost mantle shear wave attenuation model in the Tibetan region. Beneath the central and north parts of the Tibetan plateau the Sn waves are strongly attenuated, while relatively weaker attenuation can be observed in the perimeter of the plateau, i.e., the Himalaya mountains in the south, Tarim and Qaidam basins and Eastern Kunlunshan terrain in the north, and Sichuan basin in the east. These weak attenuation regions are likely where the old crustal fragments were deposited during the collision between the Indian and Asian plates. In contrast, strong Sn attenuation likely indicates local lithospheric delamination in central and eastern Tibet. Furthermore, the correlation between strong Sn and Lg attenuation zones reveals the potential mantle upwelling with deep heat sources invading the crust.
Vegetation phenology and its response to climate change in the Yellow RiverBasin from 2001 to 202
Authors: yichen wang , jie he , liang he , yujie zhang , xiaoping zhang
Published: March 2024

     Vegetation phenology is widely recognized as a comprehensive indicator of global climate change. Studying the spatiotemporal characteristics and trends of regional vegetation phenology can improve our understanding of the stability and dynamic changes of the ecosystem. Based on the 16day, 250m resolution MODIS NDVI data from 2001 to 2020, this study used the S-G filtering method and the relative threshold method to extract vegetation phenology parameters in the Yellow River Basin. Combined with the ERA5-LAND hourly climate reanalysis dataset and CHIRPS daily precipitation dataset provided by GEE platform, using trend analysis and partial correlation analysis methods, we explored the spatial distribution characteristics and change trends of vegetation phenology in different vegetation zones under global climate change.We also analyzed its response to climate factors.The results show that: (1) the climate in the Yellow River Basin presented a warm and humid development trend from 2001 to 2020, with an annually average temperature increase of 0.15℃/10a (P>0.05) and an annual precipitation increase of 24mm/10a (P
Uncertainty Projected Mapping: A Bayesian tool for generating site response maps with statistically significant resolutions   
Authors: Chakraborty Anirban , Goto Hiroyuki , Sawada Sumio
Published: March 2024

Site response maps are mostly proxy-based. The map resolutions are driven by the resolutions of the digital elevation model. Although high-resolution maps are seemingly more enriched with local information, these details are not always supported with in-situ data. The high-resolution maps are reliable only when the in-situ data supports it. Without in-situ data available, a low-resolution map might be more reliable. Depending on the availability of in-situ data, a site response map with spatially varying map resolutions would better represent the actual ground conditions. In this study, we introduce uncertainty projected mapping (UPM) to generate statistically significant map resolutions. UPM is Bayesian-based and considers the statistical significance of differences in neighborhood values in determining the posterior site response. The study area is in Osaka, Japan, where dense borehole data from the Kansai Geo-informatics Network is available. In the Bayesian framework of UPM, the site responses estimated using 1D seismic ground response analysis at this borehole network constitute the likelihood. In the first case study, a non-informative prior (uniform) is employed to generate the posterior UPM site response map. The UPM map shows the presence of statistically significant map resolutions, which in-situ data can explain. In the second case study, the available proxy-based site responses are employed as an informative prior to generate the posterior UPM map. The results show that proxy-based site responses have been updated only at meshes with in-situ data. However, these updates also show statistically significant resolutions explainable by the in-situ data. The results of both case studies show that the statistically significant map resolutions of the UPM site response map better represent the in-situ data.   
Precise point positioning with LEO augmentation: results from two experimental satellites
Authors: Li Wenwen , Li Min , Huang Tengda , Chang Chuntao , Zhao Qile
Published: March 2024

Using LEO satellites for positioning and navigation has been a research hotspot in the GNSS community in recent years. As the LEO satellites are much closer to earth and move much faster relative to earth than GNSS, precise point positioning (PPP) convergence time can be substantially improved. Various simulation studies on LEO augmentation have been carried out, but its performance with real LEO observations in a real-world environment is rarely reported. The CENTISPACETM system, which is developed by Beijing Future Navigation Tech Co., Ltd., has launched four experimental satellites in the last two years, providing a good opportunity for studying LEO augmentation. We collect real LEO navigation observations from two CENTISPACETM satellites using a regional network. Before conducting LEO-augmented PPP, orbit determination and time synchronization (ODTS) for the experimental LEO satellites are first investigated, and a data-processing framework is established using the space-borne GNSS observations from LEO satellites and the LEO augmentation observations from ground stations. The LEO-augmented PPP algorithm is then derived, with a focus on the LEO relativistic effect. With these bases, we analyze the LEO-augmented PPP performance with different GNSS systems (including GPS, BDS, and Galileo) combined with LEO satellites. The static PPP tests using one (G/C/E), two (GC/GE/CE), and three (GCE) GNSS systems show that the average convergence time is significantly reduced with the participation of the two LEO satellites, from 32.7, 17.9, and 14.2 min to 16.7, 8.9, and 5.7 min, respectively. This indicates that adding only two LEO satellites improves the convergence times of static PPP with one, two, and three GNSS systems by 48.9%, 50.2%, and 59.8%, respectively. For PPP precision evaluation, the GNSS-only 3D positioning errors are 6.1, 4.6, and 4.6 cm with one, two, and three systems, respectively. They are reduced to 5.2, 3.9, and 3.8 cm by adding two LEO satellites, respectively. The corresponding improvements are 13.9%, 16.4%, and 18.8%, respectively. The above study not only validates the customized processing framework and strategy for LEO augmentation processing but also demonstrates the great potential of LEO augmentation. With more LEO satellites to be deployed in the future, much larger improvements can be achieved.