bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of leadership in education as a decisive factor for the Communication of Sciences: The case of the European project Connect  (Horizon2020)
Authors: Kartsonakis Emmanouil , Kokkori Athina
Published: March 2024

The term "Science Communication" describes the scientific field of theoretical knowledge and practical skills that focuses on issues of two-way communication between the "scientific laboratory" and society, but also on communication between scientists coming from different fields of expertise. Its integration into school environments and educational institutions is an absolutely innovative action in the educational landscape. In addition, it can be safely considered as an expression of leadership of the persons and agencies involved since the role of the people who are called upon to apply the principle of leadership consists mainly in the management and coordination of systems and groups both on a synchronous and a longitudinal level: Leaders should contribute catalytically in the areas of motivating, supporting and developing colleagues, cultivating solidarity, encouraging innovative actions, establishing and defending the appropriate work culture and, ultimately, shaping strategy and vision. In short, leaders are actually charged with the task of achieving the goals set at the collective level by exerting a positive influence on the behavior of his associates, an effect that can greatly activate the feelings of passion, excitement and assimilation that characterize the scientific phenomenon. A typical case of all the above mentioned is the project Connect (https://www.connect-science.net/), a three-year project (2020-2023) in which the Regional Directorate of Education of Crete participated, included in the European Program "Horizon 2020" in framework of the "Science with and for Society" (SwafS) module. It was aimed at schools and offered a model that strengthens children's confidence in their engagement with science as a method of solving everyday problems and at the same time brings them into contact with scientists by involving parents and the local community. In other words, Connect tried to foster the belief that “science is for me”. Its evaluation has shown that the successful exercise of leadership, both at the level of the project coordinators and at the level of the principals of the participating schools, has been the critical factor for the success of the project and the achievement of the goal, i.e. Communication of Science with society.
Does nitrogen management in winter wheat affect its yield and nitrate-N leaching in a wheat-soybean double cropping system?
Authors: Ola Oluwaseun , Guzel Osman , Gage Karla , Williard Karl , Schoonover Jon , Mueller Steffen , Sadeghpour Amir
Published: March 2024

Conventional corn (Zea mays L.)-soybean (Glycine max L.) rotation contributes to nitrate-N and phosphate leaching to waterbodies causing water quality concerns. Two strategies that could minimize N and P losses include (i) incorporating winter rye (Secale cereale L.) (WR) as a cover crop to capture residual nutrients or (ii) intensifying the corn-soybean rotation with winter wheat (WW) (Triticum aestivum L.) (Double cropping). Double cropping WW at a right N management could increase farm profit and provide incentives for adoption as well. A trial was established at two sites (Carbondale, and Belleville, IL) to evaluate soybean and overall cash crop performance along with nitrate-N and phosphate losses in a single season [soybean following a no-cover crop control vs. WR as compared to three double cropping scenarios (low, medium, and high intensity N management of WW prior to soybean). The results indicated that double cropping decreased soybean yield regardless of N management intensity during the previous WW. Nitrogen addition to WW resulted in increased nitrate-N leaching during the WW phase but at medium and high N intensity scenarios, decreased the nitrate-N leaching during the following soybean phase and overall WW-soybean growing seasons suggesting double cropping could minimize N losses and provide farm profit.
Miocene basaltic lavas from Chios Island: Petrogenetic implications
Authors: Kalantzi Lemonia , Giamas Vasileios , Koutsovitis Petros , Petrounias Petros , Hauzenberger Christoph , Ntaflos Theodoros
Published: March 2024

Extensional processes related to subduction initiation stages often result in the formation of back-arc basins. In central Anatolia and the northern-central Aegean, the main lithotypes geochemically correspond to high-K calk-alkaline rocks that formed during the Early Miocene, while volcanism in the Middle Miocene was predominantly Na-rich. The latter lithotypes were in most cases significantly affected by differentiation processes. On the island of Chios, volcanism is comprised of lithotypes that vary significantly from alkali basalts to rhyolites. In particular, the Pyrgi lavas are fine-grained with typical porphyritic and seriate textures, which are classified as alkali basalts according to the AFM ternary plot. These lavas also exhibit positive anomalies in PM-normalized P, Sr, and Pb elements and significant enrichments in LILE (i.e., Cs, Rb, Ba), presenting a probable interaction with subduction melts. The negative correlation between SiO2 contents and the Nb/Yb ratio indicates that crustal contamination did not play a significant role during differentiation. Crystallization appears to be under extremely dry conditions due to the absence of hydrous phases (e.g., amphibole). The presence of MORB signature spinel crystals suggests the implication of a MORB-type source. In the case of Chios, the high Nb tholeiites can be associated with petrogenetic processes in which OIB-related melts interacted with the previously metasomatized mantle wedge, confirming the back-arc extension of the Northern Aegean during the Miocene and possibly to mantle delamination in the western Anatolia region.AcknowledgmentsThis work is part of the first author's MSc. research, which is financially supported by the «Andreas Mentzelopoulos Foundation».
Assessment of geodynamic predictions with surface-wave tomography in the Pacific upper mantle accounting for full 3D resolution and robust uncertainties.
Authors: Latallerie Franck , Koelemeijer Paula , Walker Andrew , Panton James , Davies Huw
Published: March 2024

Surface-waves carry important information about upper mantle structure, especially in poorly sampled areas such as oceanic regions. Surface-wave tomography models can be used to assess geodynamic simulations by comparing observed and predicted structures. However, surface-wave data are noisy and sparse resulting in tomography models being noisy and blurred pictures of the Earth's structure. As a result, tomography models can hardly be compared directly to geodynamic predictions which aim to predict the true structure of the Earth. Although challenging, assessing geodynamic simulations with surface-wave tomography requires accounting for full 3D resolution and robust uncertainties.In this study, we present a workflow to quantitatively assess geodynamic model predictions using surface-wave tomography. Specifically, we measure dispersion data for paths crossing the Pacific ocean and estimate data uncertainties including measurement and theoretical errors. We use a finite-frequency forward theory to linearly relate data to the three-dimensional Vsv structure in the upper mantle. Subsequently, we apply the SOLA (Backus-Gilbert-style) method in 3D to control and produce the full three-dimensional resolution and robust model uncertainties together with the Vsv tomography model. Equipped with this, we assess predictions for the Pacific upper mantle from a set of geodynamic simulations based on different input parameters.Preliminary results highlight physical parameters of mantle convection influencing significantly the misfit between observed and predicted structure in the Pacific upper mantle; and, for quantitative parameters, inform us on values that provide the best fits.
Recent estimates of the sea ice volume and solid freshwater flux across the Arctic’s major export passageways
Authors: Howell Stephen , Babb David , Landy Jack , Brady Mike
Published: March 2024

Sea ice export from the Arctic Ocean is important to the ice mass balance and freshwater budget of the Arctic Ocean and the delivery of freshwater to the North Atlantic. Historically, estimates of the sea ice volume and solid freshwater flux across the Arctic’s major export passageways were temporally limited in terms of available ice thickness data together with low spatial resolution satellite derived sea ice motion data. However, observational advances now provide year-round estimates of ice thickness from CryoSat-2 and high spatiotemporal estimates of sea ice motion can be derived from Senitnel-1 and the RADARSAT Constellation Mission (RCM) synthetic aperture radar (SAR) satellites. In this presentation, we present the results of merging these datasets that provide new high-quality annual and monthly estimates of the sea ice volume flux across the Arctic’s major export passageways of Fram Strait, Nares Strait, Davis Strait and the Canadian Arctic Archipelago from 2016-2022. Over our study period, the annual average volume export at Fram Strait was 1586 km3 that agrees with its longer-term decline. The annual average volume export at Nares Strait and the Canadian Arctic Archipelago was 160 km3, and 43 km3, respectively that is in agreement with longer-term increases and indicates a divergent trajectory compared to Fram Strait. The annual average sea ice volume flux through Davis Strait was 816 km3, nearly double previous estimates. Annually, a total of 1912 km3 of solid freshwater was delivered to the North Atlantic from the passageways of Fram Strait and Davis Strait. Overall, our new high-quality estimates of these sea ice variables provide updated quantities for understanding recent changes in ice mass balance and freshwater budget of the Arctic Ocean and the freshwater balance of the North Atlantic, where overturning is critical to the global climate.
ROTTnROCK: a new ERC project to investigate the influence of hydrothermal alteration on volcano instability, eruption triggers and fault reactivation
Authors: Harnett Claire , Heap Michael , Troll Valentin , Walter Thomas
Published: March 2024

Hydrothermal alteration gradually and imperceptibly changes the chemical and physical state of the rocks inside a volcano, creating a soft and unstable (or 'rotten') interior. However, the link between 'soft' volcanoes and unpredictable volcanic events remains poorly resolved. ROTTnROCK is a 6-year ERC project, running from 2024-2030, funded through the European Research Council's Synergy Call. The growing ROTTnROCK team will investigate the role of hydrothermal alteration in unpredictable volcanic hazards, such as volcanic instability, alteration-induced eruption triggering, and caldera fault (re-)activation. Specifically, we will use remote sensing and geophysics to identify where and at what scales alteration is occurring. Laboratory investigations will study the chemical fingerprint of alteration and its effects on rock mechanical properties and strength. These approaches will be coupled with 4D volcano stability simulations to produce an innovative and optimised hazard assessment workflow. We will work at selected target sites that show evidence of strong hydrothermal alteration, either associated with flank collapse, collapsing lava domes, crater lakes, or active collapse calderas. This project will transform our understanding of hydrothermal alteration and its impact on volcanic hazards, and will pave the way for strategies to predict and mitigate unexpected volcanic events caused by hydrothermal alteration.
Hydropower Dams and the Human Right to Water: an Operational Transdisciplinary Assessment Framework
Authors: Faure Julie , Muller Marc , Bertassello Leonardo , Dolan Elizabeth , Adams Ellis , Sulaimanov Rahman , Desierto Diane , Chigbu Portia , Pabillore Jonathan
Published: March 2024

There is growing urgency for actionable and standardized approach to human rights assessments of hydropower dam constructions and operations that incorporates multiple dimensions of the right to water. Yet, the water issues faced by affected communities are determined by local contexts and therefore challenging to map to universal norms like human rights in a way that is both objective and transferrable. Conversely, the human right to water extends beyond the narrow dimensions of water access and availability and also includes cross cutting obligations (e.g, self-determination and non-discrimination) and inter-related rights (e.g., rights to health, healthy environment and livelihood). The nearly universal scope of human rights with respect to water makes them challenging to apply without an operational framework to systematically diagnose challenges to their implementation in practical settings. The framework that we present addresses both challenges with a procedure to systematically diagnose multiple key dimensions of inadequate water access (e.g, green, blue and economic water scarcity or excess) and governance failures (e.g., power asymmetry or threats to hydrosocial relations). The framework then maps the diagnosed issues to specific challenges to implementation of human rights that account for their multi-dimensional nature. This work is a unique transdisciplinary collaboration between water intensive industries and experts from the fields of hydrology, governance, and human rights law. We apply the framework to representative international hydropower cases (e.g., the Lower Sesan 2 Dam in Cambodia, the Muskrat Falls Dam in Canada) to synthesize key insights on the relationship between human rights and the impacts of hydropower projects on water security and governance.
Workflows for volcano hazard assessment in cloud and HPC research infrastructures
Authors: Folch Arnau
Published: March 2024

Short and long-term probabilistic volcano hazard assessments entail the fusion of data from multiple sources with the realisation and subsequent combination of hundreds/thousands of scenarios spanning the range of system uncertainties (model inputs and parameterisations, boundary conditions, etc). Computational workflows are middleware software layers that manage and orchestrate in an automated way the multiple steps and tasks involved in this process, from data acquisition and preparation, to model executions and post-process in centralised (HPC) and/or cloud computing infrastructures. This contribution presents some examples from on-going European projects tackling computational geohazards on HPC/cloud infrastructures. For the short-term hazard assessment, the DT-GEO project (2022-2025, Grant Agreement No 101058129) is implementing a number of workflows conducting precise data-informed early warning systems and hazard assessments by harnessing world-class computational (FENIX, EuroHPC) and data (EPOS) research infrastructures. The volcano-related workflows in DT-GEO include: (i) merging of multi-parametric data from ground-based and remote observation systems (on-site monitoring networks and satellites) with global modelling of magma and rock dynamics and with AI approach; (ii) merging of real-time geostationary satellite observations with the FALL3D model to generate deterministic and ensemble-based probabilistic forecast products; (iii) merging of real-time multi-parametric data from ground-based and remote observation systems with deterministic modelling of lava flow propagation and inundation areas and; (iv) air-quality data and AI in a volcanic gas dispersal forecast context to improve operational Early Warning Systems. On the other hand, the EuroHPC ChEESE Center of Excellence (CoE) is conducting an ensemble-based volcanic dispersal across multiple scales that will lead to the first European tephra hazard map at scale covering, simultaneously, long-range dispersal and short-range fallout telescopically. This will be integrated in the EPOS Volcanic Observations TCS (VO-TCS). All these initiatives liaise, align, and synergise with EPOS and longer-term mission-like initiatives like Destination Earth.
Intercomparison of melt observed by ASCAT and modeled by Greenland Regional Climate Models
Authors: Puggaard Anna , Hansen Nicolaj , Mottram Ruth , Nagler Thomas , Scheiblauer Stefan , Simonsen Sebastian B. , Sørensen Louise S. , Solgaard Anne M.
Published: March 2024

Since the early 1990s, a decrease in the surface mass balance has contributed to about half of the observed Greenland Ice Sheet mass loss. Since surface melt is the primary driver of surface mass loss, an accurate representation of surface melt is crucial for understanding the surface mass balance and, ultimately, the total contribution to rising sea levels. Although Regional Climate Models (RCMs) can simulate ice-sheet-wide melt volume, significant variability exists among state-of-the-art RCMs, underpinning the need for validation of the melt. Here, we explore a novel processing of Advanced SCATterometer (ASCAT) data, which provides estimates of the spatiotemporal variability of melt extent across the Greenland Ice Sheet. We apply these new maps to pinpoint differences in the melt products from three RCMs. Using Programme for Monitoring of the Greenland Ice Sheet & Greenland Climate Network (PROMICE GC-net) air temperature observations, we evaluate how well RCM-modeled melt volume aligns with temperature measurements. With this evaluation, we establish thresholds for the RCMs to identify the amount of meltwater before it is observed at the AWS stations, thus allowing us to infer melt extent in RCMs. Results show that applying thresholds, informed by in-situ measurement, reduces the differences between ASCAT and RCMs and minimizes the discrepancies among RCMs. We leverage the differences between modeled melt extent and ASCAT-observed melt extent to further pinpoint (i) limitations in ASCAT's melt detection, including misclassification in the ablation zone as well as a temporal melt onset bias, and (ii) biases inherent in RCMs, including variability in albedo schemes, snow layer thickness, and temperature and radiation biases in the boundary forcing.
Global trends in forest fragmentation using multiple metrics
Authors: Zou Yibiao , Crowther Thomas , Smith Gabriel , Ma Haozhi , Mo Lidong , Wu Zhaofei , Rebindaine Dominic , Zohner Constantin
Published: March 2024

Deforestation has exacerbated the fragmentation of habitats into smaller, more isolated patches, driving global declines in biodiversity. Yet, a comprehensive global perspective of the trends in forest fragmentation, and its key drivers in relation to forest cover change remains elusive. To provide a comprehensive global overview of recent changes in forest fragmentation, we compare multiple fragmentation metrics, including those that are sensitive to forest cover and those that are not. Our analysis reveals that, according to cover-sensitive metrics that reflect the ecological implications of forest fragmentation, 52% of the world's forests have become more fragmented over the last two decades, a trend that is primarily attributed to increased deforestation in tropical zones. This value is twice as high than estimates from previous research, which estimated that forest fragmentation is declining across 75% of the global forest area. This discrepancy arises from a mathematical artifact, as previous cover-insensitive metrics equate declines in forest cover with decreased fragmentation. By adjusting for this and focusing on metrics that capture the ecologically relevant aspects of forest fragmentation, our study highlights a worrying trend: the ecological integrity of the global forest system has been significantly deteriorating in recent decades. This underscores the importance of using appropriate metrics to accurately assess the ecological impacts of forest fragmentation, especially in the context of global environmental change.
Aerosols enhance winter fog lifetime over North India
Authors: Nair Arun , Sarangi Chandan , Qian Yun
Published: March 2024

Anthropogenic aerosols affect cloud properties and change theirlifetime, a phenomenon dubbed as aerosol-cloud interactions (ACi). Radiation fog is asurface-level cloud formed due to night-time radiative cooling of the land surface. Each year,north India experiences several prolonged fog events. These multi-day fog episodes canaffect surface visibility and air quality, affecting human health and the transportation sector.From long-term observations, we find that the fog duration and foggy days are enhancedduring high aerosol loading periods over north India.However, the mechanistic role of heavy aerosol pollution on the evolution, lifetime,and frequency of North Indian fog episodes is still poorly understood. Using chemistry-coupled regional model simulations, we find ACi leads to fog lifetime enhancement byproducing smaller droplets and reducing the droplet deposition rate. During the daytime, theenhanced activation of aerosols into droplets prevents evaporation from the surface.Interestingly, during this period, the aerosol radiative effect also helps produce conducivesurface conditions to delay fog dissipation. The unequivocal role of aerosol effects on the foglifetime over North India suggests the urgent need to regulate particulate pollution to reducelong periods of fog.
ELMO: ELectron Microburst Observatory mission to study microbursts
Authors: Kanekal Shri
Published: March 2024

We describe the ELectron Microburst Observatory mission, ELMO  which is proposed as  aCubeSat constellation mission to fully characterize microburst event spatial extent systematically for the first time both in latitude  and longitude. ELMO comprises 4 CubeSats two per orbit plane in two orbit planes. ELMO will fly in a high inclination LEO at about 500 km in altitude. The CubeSats will systematically separate both in latitude and longitude over the mission lifetime and will carry MERIT, Miniaturized Electron and Proton Telescope as the the payload. MERIT has been built,tested and delivered  to fly on NASA's HERMES, Lunar Gateway mission. MERIT is a solid state detector particle telescope with two identical sensor heads pointed zenith- and nadir-wards enabling measurement of both downgpoing and upwelling electrons thereby accurately estimating  electron precipitation into the atmosphere.  MERIT  will measure electron and protons over a wide energy range in multiple differential channels with a very time resolution of less than 4 ms.    ELMO will quantify for the first time the contribution of microbursts to radiation belt electron loss using systematic coordinated multipoint measurements. Energetic electron precipitation affects atmospheric chemistry and therefore climate change. ELMO measuresmicrobursts with unprecedented time and energy resolution. ELMO provides critical knowledge of electron loss processes required for quantitative prediction of global electron fluxes.
Geological mapping of Kuiper Crater: a break within Mercury crust
Authors: Carli Cristian , Giacomini Lorenza , Massironi Matteo , Zambon Francesca , Galiano Anna , Capaccioni Fabrizio , Palumbo Pasquale
Published: March 2024

The results from planetary investigation in the last years strongly point out that the integration of compositional information with the morphology, stratigraphy and tectonics permits to produce a more comprehensive geological approach, obtaining geological maps instead of purely morpho-stratigraphic maps. In this view, firstly PLANMAP project, and then GMAP (within EUROPLANET-RI 20-24), have given indications on different approaches to follow for such integration.Investigating the surface of Mercury is an important task of the Bepicolombo mission. To be prepared for this task we are investigating the data obtained by past MESSENGER mission in order to understand which geological features and/or region of Mercury should hide key information.In this work we investigate the Kuiper crater (62 kilometer in diameter) which overlies the northern rim of the larger crater Murasaki. The Kuiper crater is one of the highest albedo features on the surface of Mercury with an important ray system, indicative of  its young age. From this point of view Kuiper can be considered an important feature on hermean surface history, such as to give the name at the last period of Mercury timeline (the Kuiperian age). However, on the other side,its relatively young age does not permit it to investigate the local geology by using the global basemaps, since the albedo is saturating within the crater, making difficult to understand the variegation on it and on the proximal and distal ejecta. Whereas considering the color variegation from the different filters of the WAC camera onboard MESSENGER, at relatively high spatial resolution (385 m/px), we clearly highlighted how several peculiar geological features arise. These regions have been later investigated by ad-hoc mosaics considering the highest resolution images available (~ 120 m/pixel) from the NAC camera onboard MESSENGER.The extension of the ejecta could be improved and differentiated from reflectance properties of the crater floor, showing an asymmetry towards S-SE. Moreover, the crater wall seems to reveal the possible impact direction. Evidence of pyroclastic-like material, from spectral reflectance properties, are present on the N-E wall, whereas from north to west the terraced wall seems to show the presence of re-melted material. Interestingly, two different hollows-like terrain are present on both the inner peaks and on the southern wall, indicating that hollows could be emplaced on different bedrock terrains. In addition, the spectral indication shows a clear distinction from Kuiper material with respect to the Murasaki terrains.We want to acknowledge the GMAP, Europlanet RI 20-24 grant n.: 871149-GMAP and the Bepicolombo (SIMBIO-SYS) project, ASI-INAF agreement n.: 2017-47-H.
Side discharges on positively charged lightning leaders
Authors: Yuan Shanfeng , Qie Xiushu , Jiang Rubin , Wang Dongfang
Published: March 2024

Recent observations unveiled two types of side discharges associated with positive leaders: needle discharges and nearby bidirectional leaders. The formation mechanism and connections of two phenomena remained unclear due to the lack of synchronous optical detection and radio mapping data. Here we present the first high-speed video and low-frequency lightning mapping results. Negative branches of nearby bidirectional leaders can propagate after connecting to the parent positive channel, and needle discharges act as positive connecting leaders. Our research shows that positive leaders exhibit unconventional channel extensions, maintained by frequent recoil leaders, sharing characteristics with streamer discharges. Notably, when two approaching positive leaders develop in this manner, they can eventually collide. These findings significantly advance our understanding of side discharges on positive leaders, offering fresh insights into these intriguing phenomena.
Genetic Control and Phenotypic Plasticity of Root Cortical Aerenchyma in Maize
Authors: Schneider Hannah
Published: March 2024

The functional role and genetic control of many root anatomical and architectural traits are poorly understood. Our research focuses on characterizing root traits for enhanced stress tolerance and identifying genetic mechanisms controlling the expression of root traits. We have identified a candidate gene for root cortical aerenchyma formation which mapped to a root cortex-expressed bHLH transcription factor gene. A bHLH121 Mu transposon mutant line and a CRISPR/Cas9 loss-of-function mutant exhibited reduced root cortical aerenchyma formation, whereas an overexpression line exhibited significantly greater root cortical aerenchyma formation when compared to the wildtype line in many environments. Overall functional validation of the bHLH121 gene’s importance in root cortical aerenchyma formation provides a functional marker to select varieties with improved soil exploration and thus yield. Characterization of these lines under suboptimal water and nitrogen availability in multiple soil environments revealed root cortical aerenchyma is plastic in response to abiotic stress. Our results suggest that phenotypic plasticity is highly quantitative and plasticity loci are distinct from loci that control trait expression in stress and non-stress conditions. The identification of genes and functional phenotypes of root traits will facilitate efforts for the development of novel nutrient and water efficient crop varieties.
Trend-Preserving Deep Learning for Multivariate Bias Correction and Downscaling of Climate Models
Authors: Tian Di , Wang Fang
Published: March 2024

Global climate models (GCMs) or Earth system models (ESMs) exhibit biases, with resolutions too coarse to capture local variability for fine-scale, reliable drought and climate impact assessment. However, conventional bias correction approaches may cause implausible climate change signals due to unrealistic representations of spatial and intervariable dependences. While purely data-driven deep learning has achieved significant progress in improving climate and earth system simulations and predictions, they cannot reliably learn the circumstances (e.g., extremes) that are largely unseen in historical climate but likely becoming more frequent in the future climate (i.e., climate non-stationarity).  This study shows an integrated trend-preserving deep learning approach can address the spatial and intervariable dependences and climate non-stationarity issues for downscaling and bias correcting GCMs/ESMs. Here we combine the super-resolution deep residual network (SRDRN) with the trend-preserving quantile delta mapping (QDM) to downscale and bias correct six primary climate variables at once (including daily precipitation, maximum temperature, minimum temperature, relative humidity, solar radiation, and wind speed) from five state-of-the-art GCMs/ESMs in the Coupled Model Intercomparison Project Phase 6 (CMIP6). We found that the SRDRN-QDM approach greatly reduced GCMs/ESMs biases in spatial and intervariable dependences while significantly better reducing biases in extremes compared to deep learning. The estimated drought based on the six bias-corrected and downscaled variables captured the observed drought intensity and frequency, which outperformed the state-of-the-art multivariate bias correction approach, demonstrating its capability for correcting GCMs/ESMs biases in spatial and multivariable dependences and extremes.
Africa's Climate Response to Marine Cloud Brightening
Authors: Odoulami Romaric C. , Hirasawa Haruki , Kouadio Kouakou , Patel Trisha D. , Quagraine Kwesi A. , Pinto Izidine , Egbebiyi Temitope S. , Abiodun Babatunde J. , Lennard Christopher , New Mark G.
Published: March 2024

Climate intervention through solar radiation modification is one proposed method for reducing climate risks from anthropogenic warming. Marine Cloud Brightening (MCB), one such approach, proposes to inject sea salt aerosol into a regional marine boundary layer to increase marine clouds' reflectivity. This study assessed the potential influence of four MCB experiments on the climate in Africa using simulations from the Community Earth System Model (CESM2) with the Community Atmospheric Model (CAM6). Four idealised MCB experiments were performed with the CESM2(CAM6) model under a medium-range background forcing scenario (SSP2-4.5) by setting cloud droplet number concentrations to 600 cm-3 over three subtropical ocean regions: (a) Northeast Pacific (MCBNEP); (b) Southeast Pacific (MCBSEP); (c) Southeast Atlantic (MCBSEA); and (d) the combination of these three regions (MCBALL). The CESM2(CAM6) model reproduces the observed spatial distribution and seasonal cycle of precipitation and minimum and maximum temperatures over Africa and its climatic zones well. The results suggest that MCBSEP would induce the strongest global cooling effect and thus could be the most effective in decreasing (increasing) temperatures (precipitation) and associated extremes across most parts of the continent, especially over West Africa, in the future (2035-2054) while other regions could remain warmer or dryer compared to the historical climate (1995-2014). While the projected changes under MCBALL are similar to those of MCBSEP, MCBNEP and MCBSEA could result in more warming and, in some regions of Africa, create a warmer future than under SSP2-4.5. Also, all MCB experiments are more effective in cooling maximum temperature and related extremes than minimum temperature and related extremes. These findings further suggest that the climate impacts of MCB in Africa are highly sensitive to the deployment region.
Correlation of wind and precipitation annual aggregate severity of European cyclones
Authors: Jones Toby , Stephenson David , Priestley Matthew
Published: March 2024

The risk from compound natural hazards (such as extratropical cyclones) can be large, but the aggregate loss over yearly timescales is significantly greater. The total insured losses from three European cyclones in February 2022 was over €3.5 billion.This study has investigated the correlation between wind and precipitation annual aggregate severity caused by extra-tropical cyclones over the Europe-Atlantic region (from 30°N 100°W to 75°N 40°E ) in the 41 years of ERA5 reanalyses from 1980-2020.Simple aggregate severity indices were constructed by summing exceedances above chosen thresholds of wind gust speed maxima and precipitation totals for all storms in a year that pass within 5° radius of each grid point location.At low thresholds, there is a strong positive correlation between wind and precipitation aggregate severity most likely induced by the common dependence on the total number of storms. However, at higher thresholds, where the aggregate indices are expected to be better predictors of wind and flood losses, negative correlations start to appear especially over western Europe e.g. a correlation of -0.22 for severity indices aggregated over France at thresholds of 20ms-1 and 20mm.This suggests that accumulated wind and flood losses in Europe should not be assumed to be either independent or positively correlated, and that there is a potential for risk diversification.
Re-evaluating Rapid Glacier Retreats: Hektoria Glacier’s Unprecedented Tidewater Collapse
Authors: Ochwat Naomi E. , Scambos Ted A. , Anderson Robert S. , Walker Catherine C. , Fluegel Bailey L.
Published: March 2024

Hektoria Glacier on the Eastern Antarctic Peninsula underwent a heretofore unseen rate of tidewater-style glacier retreat from 2022 to 2023 after the loss of decade-old fast ice in the Larsen B embayment. The glacier has retreated 25 km between February 2022 and January 2024, of which at least 8-13 km was grounded ice. Remote sensing data in the months following the fast ice break-out reveals an ice flow speed increase of up to 4-fold, and rapid elevation loss up to 20-30 m, representing an 8-fold increase in the glacier thinning rate. Hektoria and Green Glaciers underwent three phases of retreat displaying differing calving styles. During the first two months after the loss of the fast ice in January 2022 the Hektoria-Green ice tongue calved large tabular bergs. In March 2022, an abrupt change in Hektoria’s calving style was observed, changing from large tabular icebergs to buoyantly rotated smaller bergs. Following this transition, Hektoria underwent several short periods of rapid retreat. In December 2022, 2.5 km of grounded ice were lost over 2.5 days. These retreat rates for grounded tidewater ice are greater than any reported in the modern glaciological record. Here we examine the evidence for locating the pre-fast ice break-out grounding zone as well as the drivers that could cause such a rapid retreat. We link these observations to known causes of glacier instability, such as Marine Ice Sheet Instability and Marine Ice Cliff Instability, as well as the classical tidewater glacier retreat cycle.
Lateral variations of density and composition in the Martian south polar layered deposits
Authors: Genova Antonio , Petricca Flavio , Andolfo Simone , Gargiulo Anna Maria , Sulcanese Davide , Mitri Giuseppe , Chiarolanza Gianluca
Published: March 2024

A joint analysis of subsurface sounding, topography and gravity data is presented in this study to provide constraints on the lateral density variations of the south polar layered deposits (SPLD). The enhanced resolution of the gravity field enables a thorough characterization of the signal associated with the polar deposits that highly correlates to the surface global topography. A novel iterative method is used to determine the radial gravity disturbances that depend on the density contrast and topography of the surface deposits across the polar cap. By using a constrained least-squares approach on localized three-dimensional mass concentrations (mascons), we locally inverted the bulk density from the gravity disturbances, leading to a new map of its lateral variations.We thus leverage our retrieved map of the lateral density variations to provide bounds on the volumes of the main constituents of the SPLD. By assuming that the polar cap is composed of water ice, carbon dioxide ice and dust, a preliminary analysis of the compositional distribution is carried out. Our results show with unprecedented resolution extensive regions with bulk density consistent with pure water ice. The resulting map of the SPLD composition is fully consistent with complementary data, including the mass fraction of water-equivalent hydrogen measured through epithermal neutron and fast neutron counting rates acquired by the Mars Odyssey Neutron Spectrometer (MONS).
Four decades (and counting) of Satellite-based Surface Solar Radiation data - The CM SAF SARAH-3 and CLARA-A3 Climate Data Records 
Authors: Trentmann Jörg , Pfeifroth Uwe
Published: March 2024

The incoming surface solar radiation is an essential climate variable as defined by GCOS. Long term monitoring of this part of the earth’s energy budget is required to gain insights on the state and variability of the climate system. In addition, climate data sets of surface solar radiation have received increased attention over the recent years as an important source of information for solar energy assessments, for crop modeling, and for the validation of climate and weather models; all applications are requiring high-quality and temporally-consistent data records.Gridded regional and global data records of the surface irradiance are available based on satellite measurements as well as derived from numerical models, e.g., reanalysis systems. For climatological analyses, long-term data records, covering multiple decades, are required. SARAH-3 and CLARA-A3, the satellite-based climate data records from the EUMETSAT Satellite Application Facility on Climate Monitoring (CM SAF), provide data for more than 4 decades already, starting in 1983 and 1979, respectively, and are providing temporally consistent near real-time data.Here, we present the surface solar radiation data from the SARAH-3 and the CLARA-A3 climate data records for Europe. Evaluation results using surface reference data from BSRN / GEBA and other sources document the quality of the satellite-based data in terms of accuracy and temporal stability. The variability, the changes, and the trends in surface radiation are presented and discussed. Additional data, e.g., top-of-atmosphere fluxes and cloud coverage, are used to assess potential causes for the trends and variabilities found in the surface solar radiation in Europe.  
Impacts of Climate and Land use Changes on Streamflow in the Mun-Chi River Basin, the Largest Tributary of the Mekong River
Authors: Inseeyong Nantawoot , Xu Mengzhen
Published: March 2024

The impact of climate change and human activities poses significant challenges in the tropical region of Southeast Asia, specifically within the Mun-Chi River Basin, the largest tributary of the Mekong River in Thailand. The bias-corrected MPI-ESM1-2-LR, the most appropriate Global Climate Model (GCM) under the Coupled Model Intercomparison Project Phase 6 (CMIP6) for projecting Mun-Chi River flow, represent future climate variations in the basin. The analysis reveals forthcoming transformations in future land use, with cropland areas transitioning into forests and urban areas. The projected annual streamflow contributing to the Lower Mekong River is expected to increase by 1.14% to 3.49% in 2023-2035 and 1.84% to 4.26% in 2036-2050, with 67.17% attributed to climate change and 32.83% to land-use change. Temporal variations in the future flow regime reveal a wetter wet season and a drier dry season in this catchment. During the wet season, streamflow is projected to rise by 4.97% to 17.67% in 2023-2035 and 9.97% to 24.08% in 2036-2050. In contrast, the dry season is expected to experience a decrease of -2.69% to -9.15% in 2023-2035 and -6.28% to -17.10% in 2036-2050. These seasonal contrasts suggest a potential increase in extreme hydrological events, presenting challenges for efficient water resource management in this watershed and downstream countries. Consequently, effective water regulation and land-use policies are deemed crucial for sustainable management in the Mun-Chi River Basin.
A Step Towards Global Hydrologic Modelling: Accurate Streamflow Predictions In Pseudo-Ungauged Basins of Japan
Authors: Servia Hemant , Albrecht Frauke , Saxe Samuel , Bierti Nicolas , Kawasaki Masatoshi , Kurihara Shun
Published: March 2024

In addressing the challenge of streamflow prediction in ungauged basins, this study leveraged deep learning (DL) models, especially long short-term memory (LSTM) networks, to predict streamflow for pseudo ungauged basins in Japan. The motivation stems from the recognized limitations of traditional hydrological models in transferring their performance beyond the calibrated basins. Recent research suggests that DL models, especially those trained on multiple catchments, demonstrate improved predictive capabilities utilizing the concept of streamflow regionalization. However, the majority of these studies were confined to geographic regions within the United States.For this study, a total number of 211 catchments were delineated and investigated, distributed across all four primary islands of Japan (Kyushu - 32, Shikoku - 13, Honshu - 127, and Hokkaido - 39) encompassing a comprehensive sample of hydrological systems within the region. The catchments were obtained corresponding to the streamflow observation points and their combined area represented more than 43% of Japan's total land area, after accounting for overlaps. After cleaning and refining the streamflow dataset, the remaining catchments (198) were divided into training (~70%), validation (~20%), and holdout test (~10%) sets. A combination of dynamic (time-varying) and static (constant) variables were obtained on a daily basis corresponding to the daily streamflow data and provided to the models as input features. However, the final model accorded higher significance to dynamic features in comparison to the static ones. Although the models were trained on daily time steps, the results were aggregated to monthly timescale. The main evaluation metrics included the Nash-Sutcliffe Efficiency (NSE) and Pearson’s correlation coefficient (r). The final model achieved a median NSE of 0.96, 0.83, & 0.78, and a median correlation of 0.98, 0.92, & 0.91 corresponding to the training, validation, and test catchments, respectively. For the validation catchments, 90% exhibited NSE values greater than 0.50, and 97% demonstrated a correlation surpassing 0.70. Correspondingly, these proportions were observed at 77% and 91% for the test catchments.The results presented in this study demonstrate the feasibility and efficacy of developing a data-driven model for streamflow prediction in ungauged basins utilizing streamflow regionalization. The final model exhibits commendable performance, as evidenced by high NSE and correlation coefficients across the majority of the catchments. Importantly, the model's ability to generalize to unseen data is highlighted by its remarkable performance on the holdout test set, with only a few instances of lower NSE values (< 0.50) and correlation coefficients (< 0.70).
Assessing the Impact of Ice Velocity Observations on Ice Sheet Mass Loss Projections from the Amundsen Sector
Authors: Recinos Beatriz , Goldberg Daniel , Maddison James R.
Published: March 2024

Ice streams in the Amundsen Sea Embayment (ASE) are some of most rapidly thinning in Antarctica, experiencing ocean-driven grounding-line retreat and increased mass loss. Ice streams in this sector are crucial for maintaining the stability of the West Antarctic ice sheet, which contains enough ice to raise global mean sea-level by 5.3 m. Ice sheet models are our main tool to make projections of ice sheet mass loss or volume above floatation (which is equivalent to sea level rise). Standard methodologies consist of constraining model parameter fields using satellite observations, and then simulating model response to climate forcing. However, to date there is no comprehensive assessment of how sensitive these projections are to different satellite products or to spatial variations in ice velocity observations, or changes in the spatial distribution of unknown model parameters.  

Mapping the sensitivity of ice streams to a given set of model inputs can be done using an ensemble of simulations and running the model workflow tens (or hundreds) of thousands of times. Automatic Differentiation (AD) and data assimilation, however, provides an efficient method to perform this analysis and get these sensitivity maps at the scale of the model’s mesh. Here we use the ice sheet model Fenics_ice and its AD capabilities to construct maps of the sensitivity of volume above floatation to changes in the calibrated unknown model parameters, as well as changes in ice velocity observations. Our preliminary results show that the sea level rise forecast is more sensitive to ice velocity changes at the grounding line and to changes to the basal drag coefficient at those same locations.  