bluuebunny/crossref_metadata_2025 huggingface dataset:
An operational prototype for seasonal drought prediction in a Mediterranean region
Authors: Torres-Vázquez Miguel Ángel , Gincheva Andrina , Halifa-Marín Amar , Montavez Juan Pedro , Turco Marco
Published: March 2024

Droughts create significant societal and environmental challenges. Accurate seasonal drought forecasting can provide early insights into potential impacts, serving as a vital resource for informed decision-making. An operational prototype with high spatial resolution is presented to predict seasonal meteorological drought in Spain (4SPAIN).The prediction system is inspired by an empirical method known as Ensemble Streamflow Prediction (ESP; Day, 1985). The model forecasts drought using the Standardized Precipitation Index (SPI6; Mckee et al., 1993) based on accumulated monthly precipitation data over 6 months (Turco et al., 2017). Due to the near real-time availability of ERA5 and its high similarity with the Spanish Meteorological Agency Spanish database (Torres-Vázquez et al., 2023), this database was chosen for the development and implementation of 4SPAIN. The validation of the model shows that it has predictive skill generally up to four-month lead time, whereas worse results come from predicting the wet season.Finally, an online operational prediction system called "Drought forecast monitor for Spain" was implemented. This low computational cost tool can provides users and competent authorities with an interactive interface to make early decisions based on updated information about the magnitude of the drought, uncertainty, alert level, and the probability of moderate drought occurrences (https://matv.shinyapps.io/app_4SPAIN/).ReferencesDay, G. N. (1985). Extended streamflow forecasting using NWSRFS. Journal of Water Resources Planning and Management, 111(2), 157–170.McKee, T. B., Doesken, N. J., y Kleist, J. (1993). The relationship of drought frequency and duration to time scales. In Eighth Conference on Applied Climatology, January, Anaheim, California, 1993, pages 17–22. American Meteorological Society.Torres-Vázquez, M. Á., Halifa-Marín, A., Montávez, J. P., & Turco, M. (2023). High resolution monitoring and probabilistic prediction of meteorological drought in a Mediterranean environment. Weather and Climate Extremes, 40, 100558.Turco, M., Ceglar, A., Prodhomme, C., Soret, A., Toreti, A., & Francisco, J. D. R. (2017). Summer drought predictability over Europe: empirical versus dynamical forecasts. Environmental research letters, 12(8), 084006.Acknowledgements A.G. thanks  to the Ministerio de Ciencia, Innovación y Universidades of Spain for PhD contract FPU19/06536. M.T. acknowledges funding by the Spanish Ministry of Science, Innovation and Universities through the Ramón y Cajal Grant Reference RYC2019-027115-I and through the project ONFIRE, Grant PID2021-123193OB-I00, funded by MCIN/AEI/ 10.13039/501100011033 and by “ERDF A way of making Europe”.
Noise analysis of Distributed Acoustic Sensing (DAS) systems in borehole installations
Authors: Pecci Davide , Cesca Simone , Rapagnani Giacomo , Gaviano Sonja , Bocchini Gian Maria , Carelli Giorgio , Stucchi Eusebio , Iannelli Renato , Grigoli Francesco
Published: March 2024

In recent years, there has been an increasing interest in Distributed Acoustic Sensing (DAS) technology for microseismic monitoring, especially in operations involving borehole installations. Despite the widespread adoption of DAS systems in such contexts, many questions regarding the data quality of the recordings are still open. Is the DAS self-noise higher than traditional systems? How does the ambient noise recorded by a DAS system attenuate with the depth as observed with traditional geophones? It is known that various noise types, including optical, thermal, and mechanical noise coupled with the fiber, affect DAS data. Additionally, the noise frequency band often overlaps with the signal frequency band, making frequency filtering alone inadequate for denoising. Therefore, specialized noise reduction workflows, such as FK Filtering and SVD, are necessary. Mitigating the impact of noise on DAS data remains a primary challenge for the seismological and geophysical community. This study aims to examine and characterize the noise influencing DAS data collected in borehole installations, with a specific focus on the data recorded at the Frontier Observatory for Research in Geothermal Energy site in Utah, USA. We use Power Spectral Density analysis to assess depth-dependent noise reduction and its temporal variations. Furthermore, the depth dependence of the signal-to-noise ratio for various microseismic events is evaluated. Finally, a comparison is drawn with geophones data colocated with the fiber, offering a comprehensive exploration of the advantages and disadvantages of the two data acquisition technologies.
Study of magnetosphere dynamics combing geospace and planetary missions
Authors: Nakamura Rumi , Slavin James , Schmid Daniel , Sun Weijie ,   Bepicolombo Earth-Flyby Interval Substorm Study Team
Published: March 2024

Solar system missions studying the sun and the planets in the inner and outer heliosphere use gravity assists of the planets to reach the target orbit of the missions. If such a maneuver happens around Earth, these observations enable us a unique multipoint observation of the magnetosphere together with other existing geospace missions as was the case of the Bepicolombo in April 2020 and the Solar Orbiter in November 2021 and is expected for JUICE in August 2024. Although the spacecraft during flybys are usually not operated in a full science mode, a new constellation with other fleet of spacecraft in Geospace can provide important information in particular for studying large-scale magnetospheric dynamics.In this presentation we discuss the three-dimensional evolution of the magnetotail current of a substorm on April 10, 2020 that took place during the Earth-flyby interval of Bepicolombo. Magnetotail disturbances are observed by GOES 17 and Cluster in the midnight region, while BepiColombo spacecraft traversed the premidnight region duskward at 9-11 RE downtail. The four Cluster satellites, which were separated mainly in north-south direction, crossed the inner magnetosphere successively from north to south. They enable us to monitor the vertical (latitudinal) structure and the sequential changes of the magnetotail current sheet until the end of the recovery phase of the substorm. Multiple dipolarizations and multiple transient field-aligned currents (FAC) were observed by Cluster. Using the unique dataset from these multi-point observations, we examine the structure of the large-scale current sheet and analyze the embedded transient intense field-aligned current disturbances. By also comparing the observations with an empirical magnetic field model, we obtain the changes of the near-Earth magnetotail structure during the multiple dipolarization event.
Response of the Hydrological Cycle to Early Eocene Warmth: Insights from DeepMIP-Eocene
Authors: Cramwinckel Marlow Julius ,   DeepMIP-Hydrology Team
Published: March 2024

Investigating how the early Eocene (∼56–48 million years ago) hydrological cycle operated under elevated atmospheric CO2 concentrations and globally higher temperatures can provide important insights into understanding of current climate change and projects of future climate. Here, we investigate the global and zonal-mean rainfall patterns during the early Eocene using an integrated data-model approach. We leverage insights from the DeepMIP-Eocene suite of model simulations in combination with a compilation of paleobotanical proxies of precipitation. In short, the mid- and high latitudes, as well as the tropical band, are characterized by a thermodynamically-dominated hydrological response to warming, and overall wetter conditions (“wet-gets-wetter”). A more complex picture is painted for the subtropics. Although these are overall characterized by negative precipitation-evaporation anomalies (“dry-gets-drier”) in the DeepMIP models, there is surprisingly large inter-model variability in mean annual precipitation. Intriguingly, we find that models with weaker meridional temperature gradients (e.g., CESM, GFDL) are characterized by a reduction in subtropical moisture divergence, leading to an increase in MAP. These model simulations agree more closely with our new proxy-derived precipitation reconstructions and other key climate metrics and imply that the early Eocene was characterized by reduced subtropical moisture divergence. If the meridional temperature gradient was even weaker than suggested by those DeepMIP models, circulation-induced changes may have outcompeted thermodynamic changes, leading to wetter subtropics, thus going against the “wet-gets-wetter, dry-gets-drier” paradigm. This highlights the importance of evaluating multiple climate metrics against sets of simulations and can provide food for thought for DeepMIP phase two.
Investigating the contribution of biogenic sinks and sources to Vienna’s CO2 budget using bottom-up modelling and tall-tower flux measurements
Authors: Fasano Enrichetta , Schmid Carmen , Moldaschl Erwin , Mayer Merlin , Braun Sebastian Konrad , Vuolo Francesco , Weiss Peter , Schume Helmut , Matthews Bradley
Published: March 2024

The importance of accurate monitoring of carbon dioxide (CO2) emissions from cities is underlined by the substantial urban contribution to global fossil fuel combustion. Typically, cities quantify emissions of CO2 using inventories and also use these models to design appropriate local mitigation policies and measures. However, inventories of individual cities can be uncertain (lack of appropriate activity data and emission factors, uncertainties in spatial downscaling) and furthermore often do not include estimates for the sector Land Use, Land-use Change and Forestry (LULUCF). While the relative, total contribution of LULUCF to a city’s annual CO2 balance may be assumed small, such an assumption should be verified. Furthermore, biogenic fluxes of photosynthesis and respiration may indeed be significant at higher temporal resolutions and omitting these fluxes can limit the conclusions drawn from comparisons of city CO2 inventories with estimates based on atmospheric CO2 observations.The Vienna Urban Carbon Laboratory is currently investigating how monitoring of CO2 emissions in Austria’s capital city can be supported by a range of atmospheric measurement methods, including a tall-tower, urban application of eddy covariance. Despite the focus on atmospheric observations, the project is also investigating the contribution of biogenic fluxes to Vienna’s net CO2 budget. A LULUCF model of annual carbon stock changes has been developed following the IPCC guidelines using inter alia local forest inventory data and spatially-explicit data on land use and urban tree crown cover. Parrellel to this, work is underway to implement spatially- and temporally resolved simulations of vegetation CO2 fluxes using semi-empirical models of photosynthesis and respiration. Ultimately, integrating these results (together with bottom-up estimates of human respiration) will provide a more meaningful comparison between the local CO2 inventory with the fluxes derived from the eddy covariance measurements.
Surface snow bromide and nitrate at Eureka, Canada in early spring and implications for polar boundary layer chemistry
Authors: Yang Xin , Strong Kimberly , Criscitiello Alison , Santos-Garcia Marta , Bognar Kristof , Zhao Xiaoyi , Fogal Pierre , Walker Kaley , Morris Sara , Effertz Peter
Published: March 2024

This study explores the role of snowpack in polar boundary layer chemistry, especially as a direct source of reactive bromine (BrOX=BrO+Br) and nitrogen (NOX=NO+NO2) in the Arctic springtime. Surface snow samples were collected daily from a Canadian high Arctic location at Eureka, Nunavut (80°N, 86°W) from the end of February to the end of March in 2018 and 2019. The snow was sampled at several sites representing distinct environments: sea ice, inland close to sea level, and a hilltop ~600 m above sea level.  At all sites, snow sodium and chloride concentrations increase by almost tenfold from the top 0.2 cm down to a depth of ~1.5 cm. Surface snow bromide at sea level is significantly enriched, indicating a net sink of atmospheric bromine. Moreover, surface snow bromide at sea level has an increasing trend over the measurement period, with mean slopes of 0.024 mM d-1 in the 0-0.2 cm layer and 0.016 mM d-1 in the 0.2-0.5 cm layer. Surface snow nitrate at sea level also shows a significant increasing trend, with mean slopes of 0.27, 0.20, and 0.07 mM d-1 in the top 0.2 cm, 0.2-0.5 cm, and 0.5-1.5 cm layers, respectively. Using these trends, an integrated net deposition flux of bromide of (1.01±0.48)×107 molecules cm-2 s-1 and an integrated net deposition flux of nitrate of (2.6±0.37)×108 molecules cm-2 s-1 were derived. In addition, the surface snow nitrate and bromide at inland sites were found to be significantly correlated (R=0.48-0.76) with the [NO3-]/[Br-] ratio of 4-7 indicating a possible acceleration effect of reactive bromine in atmospheric NOX-to-nitrate conversion. This is the first time such an effect has been seen in snow chemistry data obtained with a sampling frequency as short as one day.BrO partial column (0-4 km) data measured by MAX-DOAS show a decreasing trend in March 2019, which agrees with the derived surface snow bromide deposition flux. This indicates that bromine in the Eureka atmosphere and surface snow did not reach a photochemical equilibrium state and that the photochemical release flux of reactive bromine from snow must be a weak process and smaller than the derived bromide deposition flux of ~1×107 molecules cm-2 s-1.
Probing the Dynamics of Extreme Weather Events in the Azores, Portugal
Authors: Mondal Dhiman R. , Elosegui Pedro , Brock Lucy , Paine Scott , Mateus Pedro , Mendes Virgilio
Published: March 2024

The rapidly changing climate is escalating the frequency and intensity of extreme weather events in the Azores, Portugal. It is crucial to comprehend the dynamics of these events to mitigate them. Atmospheric water vapor data from the Global Navigation Satellite System (GNSS) and reanalysis products from an atmospheric general circulation model can be utilized to investigate the dynamics of weather fronts in the Azores Islands. A primary goal of our study is to conduct a comprehensive comparison between GNSS and MERRA2-based atmospheric reanalysis data and derive small-scale atmospheric structures with high-temporal resolution. Using statistical analysis, we will unveil the similarities and discrepancies between the two approaches in capturing atmospheric water vapor patterns. Emphasizing an exploratory methodology, we will showcase our findings using a restricted dataset that centers on specific instances of extreme precipitation witnessed in the Azores Islands.
Matching opportunistic column measurements of CO2 with pixel-wise scaled emission tracers from a forward model for the urban area of Thessaloniki – Can we detect strong sources?
Authors: Feld Lena , Schmid Pablo , Hase Frank , Ruhnke Roland , Mermigkas Marios , Balis Dimitrios , Braesicke Peter
Published: March 2024

A rapid reduction in greenhouse gas emissions is critical to limit global warming. In order to act effectively, it is important to be able to monitor emissions and their changes over time. A special interest lies in the monitoring of urban areas due to their significant contribution to the amount of global anthropogenic emissions. However, the heterogeneous structure of urban areas makes it difficult to attribute observed changes in atmospheric concentrations of e.g. CO2 to localized emission sources.Here, we present results from an opportunistic measurement campaign in the framework of the COllaborative Carbon Column Observing Network (COCCON) in Thessaloniki, Greece. During the campaign period in October 2021 and summer 2022, XCO2 amounts were observed with two EM27/SUN FTIR spectrometers located at different places in the city. A total of 20 days of co-observations at different locations were recorded, with differences between the measurement locations of up to 2 ppm.These observations are compared to regional hindcasts generated with the NWP forward model ICON-ART using emissions from the high resolution ODIAC inventory. The agreement between pairs of observed and simulated XCO2 columns obtained in this way is often limited, while other meteorological quantities are well represented in the model. Assuming that the largest source of the XCO2 discrepancies is originating from the inventory, we fragment the urban area of the inventory into different pixels, simulating the contribution of each individual pixel as a separate tracer within the model. The pixel-wise emitted tracers are scaled after run time to optimize the agreement with the observations. In this linear superposition the re-weighting of tracers imply which pixels need to be assigned with higher emissions than stated by the ODIAC inventory. As expected, the agreement between measured and modeled XCO2 columns can be significantly improved with this method, while regions with potentially high emissions (e.g. the harbor area) receive an upscaling.This demonstrates that even smaller datasets without strong emission signatures can contain extractable emission information when processed carefully in conjunction with a good meteorological forward model.
A physical model of the Gibraltar Strait: the HERCULES experiment
Authors: Negretti Maria Eletta , Tassigny Axel , Gostiaux Louis
Published: March 2024

Gravity currents are one of the key sub-mesoscale processes that drive energy transfer, impact the thermohaline structure and the vertical exchange of water masses in the ocean. At present, their representation remains difficult in numerical models. The targeted study area is the Strait of Gibraltar between the Mediterranean and the Atlantic Ocean. We present preliminary results of experiments obtained using the first realistic implementation of the Strait of Gibraltar with the adjacent Gulf of Cadiz and Alboran Sea, including all main forcings: the density difference, the barotropic tide, the Earth’s rotation and the realistic topography, scaled using available in-situ data. Detailed measurements of the velocity and density fields reveal that the large-scale circulation and the further faith of the Mediterranean waters flowing into the Atlantic Ocean are strongly influenced by the turbulent processes at small scale that take place in the main control areas, i.e. the Camarinal and Espartell sills. Two-dimensional velocity and density fields in these key regions and in several locations in the Gulf of Cadiz and Alboran Sea are obtained and turbulent fluxes and mixing are estimated. Finally, internal solitary waves are observed, possibly degenerating in a train of internal waves, generated by the tide in interaction with the topography at Camarinal sill and propagating toward the Alboran Sea. These results are analyzed to assess the impact of the parameter variation (barotropic and baroclinic forcings).
searching for solutions for Carbon-sequestration in coastal ecosystems: an international and interdisciplinary approach
Authors: Zimmer Martin ,   sea4soCiety-Consortium
Published: March 2024

Climate change-mitigation requires immediate and long-lasting drastic reductions in anthropogenic greenhouse gas emissions. As some of these emissions are considered hard-to-abate, the net-zero emissions aim can only be reached through carbon dioxide removal (CDR) strategies. Many of these rely on technical, physical or chemical approaches that are promising but not yet fully implementable nor fully accepted by society (https://cdrmare.de/en). Nature-based Solutions (NbS), by contrast, may be less efficient but enjoy high societal desirability and methodological feasibility. sea4soCiety (https://sea4society.cdrmare.de/en) aims at developing innovative approaches to enhance the potential for Blue Carbon sequestration in mangrove forests (and other blue carbon ecosystems: saltmarshes, seagrass meadows, kelp beds) through expanding their spatial extent into new areas, if and where ecologically feasible, in an environmentally sound, legally and ethically unobjectionable, socially acceptable, and economically viable manner. With the first phase (2021-2024) of the long-term project ending, I will critically shed light on the general concept, progress. Based on first findings -specifically with respect to methodology, organic matter stability and origin, faunal effects on carbon fluxes, and societal perception and acceptance-, an outlook to the second phase (2024-2027) will provide a glimpse at future plans and directions towards Blue Carbon-based climate change-mitigation through the (re-)establishment of coastal vegetated ecosystems.
New estimation models for determining the Q347
Authors: Dups Yanick , Pavia Santolamazza Daniela , Staufer Philipp , Lebrenz Henning
Published: March 2024

In Switzerland, low flows are described by the five percent quantile denoted by Q347. This threshold value not only has consequences for the planning, but also necessitates authorities to adjust the operation of pertinent infrastructure to mitigate ecological impacts on watercourses. Given a discharge timeseries spanning at least a ten-year period, determination of the Q347 can be done using the duration curve. Typically, said timeseries are not available for smaller catchments necessitating the estimation of the threshold value Q347. In Switzerland, the utilization of multiple linear regression has been established to estimate the area-specific discharge q347.The primary objective of these investigations is to estimate the Q347 value for 383 ungauged catchments in the Canton of Solothurn, each covering an area less than 100 km². Daily discharge, precipitation and temperature timeseries ranging from 1990 to 2020 were collected from 56 gauged catchments smaller than 500 km² surrounding the target area. 30 “static” parameters delineating geometry, topography, geology, land use, and drainage along with nine “climatic” parameters describing temperatures, precipitation distributions, and potential evapotranspiration were defined and computed to characterize gauged and ungauged catchments. Alongside comparing three regression methods, coupled with two adjustment techniques supplementing truncated discharge timeseries, three parameter selection methods are evaluated. The validation of the proposed models shows reduced errors and increased linear correlations between estimated and observed values compared to currently applied models. Notably, a spatially more homogeneous yet catchment-specific distribution of estimated values is observable. Particularly when timeseries remain unadjusted or adjustment is done using the Antecedent Precipitation Index (API) and the flow duration curve from a donor basin (Ridolfi, E.; Kumar, H.; Bárdossy, A., 2020), the proposed models yield promising results.Furthermore, the temporal variability of low flow events for the glacier-free catchments in the study area has been analysed. The frequency of low flow events below the threshold systematically increased over the last 30 years, while the 10-year Q347 value of said catchments has systematically decreased in the same period. The increase in low flow days leads to large errors in the estimation of the Q347 value, especially when its estimation is based on truncated timeseries. As further changes in runoff behaviour are to be expected due to climate change, extending the definition of "low flow" to include event duration and intensity alongside a fixed threshold value could offer a more suitable description.
Integrated modeling of climate change impacts on water resources: The Souss basin in Morocco
Authors: Attar Oumaima , Brouziyne Youssef , Bouchaou Lhoussaine , Ait Brahim Yassine , Chehbouni Abdelghani
Published: March 2024

Climate change has different impacts on water resources, altering hydrological cycles and exacerbating water-related challenges. Changes in precipitation patterns, including more frequent and intense droughts in semi-arid areas contribute to water scarcity and unpredictable availability. Being situated in central-western Morocco, the Souss basin (SB) is subject to high variations on many different scales and is strongly influenced not only by the variability of the climate but also by anthropogenic activities. SB is a strategic watershed that has considerable economic potential, mostly related to the agricultural sector, and has the typical assets and challenges of most Mediterranean watersheds. Allowing the best use of the limited water resources helps in planning better conservation and management strategies.  In this study, a DSS approach based on the ModSim-DSS model and recorded data about physical processes, hydraulic infrastructure features, and crop management was used to simulate the response of SB to climate change during the period 1990–2022. Observed rivers flow data were used to force the modeling framework over the study area. The results showed that the extent of climate change has had repercussions across the entire basin, particularly in terms of flow regimes and dam inflows. The simulation period witnessed a considerable decrease in the supply levels for the two most important dams in the region. Over the period between 2012 and 2019, there has been a notable reduction in water supplies for the Aoulouz dam, declining from an average of 100 Mm3 to 10 Mm3, representing a significant 52% decrease. Similarly, the ABDMNN dam experienced a substantial drop in water availability during the same period, decreasing from an average of 20 Mm3 to 3 Mm3, indicating a remarkable 89% decline. The differences among different supply sources fluctuate during the simulation period, resulting from changes in the available water inputs each year. The modelling approach used in this work helped identify the Souss basin’s potential challenges for best consideration in future sustainable water management plans.
Coupled 3D radiation deepens cumulus clouds without changing the mean surface solar irradiance
Authors: Tijhuis Mirjam , van Stratum Bart , van Heerwaarden Chiel
Published: March 2024

Most atmospheric models consider radiative transfer only in the vertical direction (1D), as 3D radiative transfer calculations are too costly. Thereby, horizontal transfer of radiation is omitted, resulting in incorrect surface radiation fields. Previous work on 3D radiative effects mainly used uncoupled 3D radiative transfer. In our current work, we study the impact of coupled 3D radiative transfer on the development of clouds, and the resulting impact on the domain average surface solar irradiance.We performed a series of realistic Large-Eddy simulations with MicroHH. We developed the option to use aerosol data from the CAMS global reanalysis to include the interactions between aerosols and radiation in our LES simulations. This makes sure our simulated radiation is in line with observations. To investigate the impact of 3D radiative transfer, we selected 12 days on which shallow cumulus clouds formed over Cabauw, the Netherlands. For each day, we performed simulations with 1D radiative transfer and with a coupled ray-tracer. The simulations with the coupled ray-tracer also include the results of uncoupled 1D radiative transfer. This allows us to compare the differences between 1D and 3D radiative transfer when the clouds are the same.  In general, our simulations with coupled 3D radiative transfer have a higher domain average liquid water path compared to our simulations with coupled 1D radiative transfer. The cloud cover is similar in both simulations, but the cloud size is increased in the simulations with coupled 3D radiative transfer. For the domain average radiation, we find that 3D radiative transfer in general decreases the direct radiation and increases the diffuse radiation, but the net effect is on average less than 1 W m-2. We can explain the differences in radiation when we look separately at the direct and diffuse radiation, the uncoupled 3D effects, and the impact of the change in the clouds. The uncoupled effect of 3D radiative transfer is an increase in global radiation, which is counteracted by a decrease is global radiation caused by the change in clouds.
Enhancing the Design of Climate Service Training Programs: Identifying Targeted Audiences for the User Learning Services for the Copernicus Program
Authors: del Pozo Maria , van der Bolt Bregje , Gulikers Judith , den Brok Perry , Ludwig Fulco
Published: March 2024

This research tackles the multifaceted challenges inherent in the design of climate service training programs, with a specific focus on the context of C3S User Learning Services. The heterogeneity of actors involved, including producers, providers, intermediaries, and users, often leads to misalignments attributable to overlooked nuances in learning needs. The primary objective is to establish consensus among trainers involved in the C3S User Learning Services regarding the identification of targeted audiences, their associated knowledge and skills, and the interests pivotal for the success of capacity-building initiatives. Utilizing the Delphi method, trainers participate in iterative rounds of questionnaires, wherein statistical measures and qualitative assessments guide the refinement process. The study introduces specific levels of agreement, distinguishing between poor, average, and strong agreement based on percentage evaluations. The structured yet flexible approach incorporates a pre-testing stage involving external experts to ensure survey clarity. With the potential inclusion of a fourth round in cases of low consensus, the research aspires to comprehensively address the diverse learning needs within the climate service domain, ultimately enhancing the efficacy of training programs, exemplified by C3S User Learning Services
Meteorological environments leading to two large fires in Southern Portugal
Authors: Purificação Carolina , Campos Cátia , Henkes Alice , Kartsios Stergios , Couto Flavio T.
Published: March 2024

The study is a step forward in the characterization of meteorological environments that favour the evolution of large and extreme fires in Southern Portugal. The region has some fire-prone areas which are recognized by the mega fires occurred in 2003, 2005, and 2018. Two numerical simulations were performed using the Meso-NH non-hydrostatic research model and used to investigate in detail the atmospheric environments of two large fires that occurred on 18th July 2012 and 19th June 2020. The simulations were configured using two nested domains with a 375 km × 375 km grid domain (D1) at 2.5 km horizontal resolution and a 150 km × 150 km domain (D2) at 500 m resolution added before the start of the fires. The vertical grid was configured with 50 stretched levels following the terrain. The initial and boundary conditions are provided by the 6-hourly operational ECMWF analyses. The large-scale circulation has been characterised using data obtained from the ECMWF's Meteorological Archival and Retrieval System. In addition to the large-scale circulation, namely the positioning of the Azores anticyclone and the thermal low development over the Iberian Peninsula, the results have shown the important role played by regional orography in creating favourable fire weather conditions. For instance, the high-resolution simulations showed the high daytime temperatures and sometimes overnight, low humidity, and strong wind gusts that favour fire spread. In July 2012, the typical sea breeze circulation affected the fire evolution, whereas the intense downslope winds favoured the fire spread in June 2020. The study brings useful guidelines for interpreting the impact of different mesoscale environments that may produce large fires, namely the orographic effects that can increase the fire susceptibility and vulnerability of some regions. This study was funded by national funds through FCT-Foundation for Science and Technology, I.P. under the PyroC.pt project (Ref. PCIF/MPG/0175/2019).
Impact of Deccan Volcanism on evolution of higher plant terpenoids
Authors: Niyolia Deepti , Dutta Suryendu , Samant Bandana
Published: March 2024

The Deccan volcanism represents one of the largest volcanic eruptions in Earth’s history. The volcanic activity significantly impacted global environmental changes and played a crucial role in the Maastrichtian period's floral and faunal diversification. The present study aims to explore the palaeovegetation during the Deccan Volcanism for better understanding of floral occurrences using biomarker proxy.
The sediment samples from the Early Cretaceous Kutch Basin and Late Cretaceous Deccan Intertrappean samples were investigated. The samples were analysed by extracting the bitumen fraction and separating it into saturates and aromatics using column chromatography. Comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry was employed to analyse the resulting fractions.
The saturated fractions of Early Cretaceous Kutch Basin were dominated by n-alkanes and acyclic isoprenoids with a slight OEP predominance and high CPI. In the Kutch samples, diterpenoids such as labdane, ent-beyerene, isopimarane etc were detected. However, in the Late Cretaceous samples only dihydrorimuene and abeitane were identified in the saturated fractions, showing limited gymnosperm contribution. Hopanes series showed C27-32 hopanoids in the Intertrappeans along with mono-unsaturated hopanes. Mono- and di-unsaturated A-ring degraded compounds, including des-A-olean-13(18)-ene, des-A-olean-12-ene, olean-12-ene, olean-18-ene, urs-12-ene, olean-2, 13(18)-diene, and A-ring degraded compounds like des-A-ursane and des-A-lupane, related to angiosperm input were recorded in the Late Cretaceous samples. Additionally, various angiosperm-derived aromatic triterpenoids were detected in the Intertrappean samples.
Based on the biomarker distribution, it was inferred that the palaeovegetation during the Cretaceous period showed a remarkable shift from gymnosperm dominated paleo-assemblage to angiosperm- dominated palaeovegetation and that the angiosperm evolved during the Cretaceous time. Overall, this study aims to shed light on the palaeovegetation during the Deccan Volcanism, providing insights into how the massive volcanic eruptions can impact the palaeoflora and paleoecology of the region.
The ups and downs of the Lascar crater floor, and the resulting fracture pattern analyzed by satellite stereo photogrammetry and 3D printed mould analog experiments
Authors: Ai Lun , Walter Thomas , Aguilera Felipe
Published: March 2024

Lava emplacement in a summit crater is often associated with unpredictable explosions and volcanic hazards, especially for volcanoes that are popular with tourists. The Lascar volcano, Chile, experienced a sudden eruption in December 2022, followed by the extrusion of lava. We acquired a series of Pleiades tri-stereo satellite images covering this new eruptive episode. Using a photogrammetric approach, we generated high resolution point clouds and orthomosaics from the satellite images. By directly comparing distances between point clouds, we are able to quantify morphological and structural details and changes. We find initial uplift of the crater floor due to lava extrusion and rockfall deposits, and evidence for subsidence and the formation of a funnel centered on the crater floor. To understand the mechanical factors controlling the uplift and subsidence of the crater floor, we designed a novel set of analogue experiments to simulate lava extrusion and subsidence inside a scaled 3D printed mould of the Lascar crater. We account for geometric and topographic effects by running these extrusion and subsidence models. Sand and sand-plaster mixtures extrude and subside from a vertical conduit at a constant rate, simultaneously recorded by a digital camera at 10-second intervals. We use particle image velocimetry (PIV) method to track and visualize displacements on the crater floor. The results show that extrusion and subsidence occurs along distinct shear faults, which are constrained by the diameter of the underlying conduit. The shear faults are represented as concentric fractures and are consistent with the ring features observed at Lascar. By comparing satellite observations with analogue models, we develop a conceptual model in which a lava extrusion is affected by withdrawal from the conduit, forming a funnel-shaped surface depression associated with inward-dipping radial erosion gullies. Thus, our observations and analogue models also help to define the position and dimensions of the volcanic conduit, which is essential for understanding future episodes of the ups and downs of the Lascar crater floor.
A parametric study of sea level and grounding line projections in the Amundsen Sea sector for coupled solid Earth - ice sheet models.
Authors: Houriez Luc , Larour Eric , Caron Lambert , Schlegel Nicole-Jeanne , Pelle Tyler , Seroussi Hélène
Published: March 2024

The evolution of the Antarctic Ice Sheet (AIS) represents one of the most important and uncertain contributions to sea level rise in the upcoming centuries. Thwaites glacier and the Amundsen Sea sector of the West Antarctic Ice Sheet (WAIS) have been identified as the continent's most critical areas. The retreat of Thwaites' glacier grounding line - the transition area where ice is no longer grounded and becomes afloat - is the subject of considerable study for modelers as it governs the collapse of the glacier. Recent advances towards coupling of dynamical ice models with Glacial Isostatic Adjustment (GIA) models has provided the means to improve grounding line projections by considering solid-Earth processes and their interactions with the cryosphere and hydrosphere. However, the spatial and temporal model resolution necessary to fully capture these interactions, and its sensitivity to model parametrization, remains elusive. We investigate the grounding line retreat of Thwaites Glacier through 2350 using the parallelized coupled physics capabilities of the Ice-sheet and Sea-level System Model (ISSM) which capture the complex interactions between solid-Earth, ice-sheets, and ocean. We incorporate realistic climatology, ocean melt rates, and GIA models and we discuss the impact of spatial and temporal model resolution, and solid-Earth parametrization, on the grounding line retreat and sea level change. © 2024 California Institute of Technology. Government sponsorship acknowledged.
Morphodynamics of three active rock glaciers and its influence on spring hydrochemistry in the Swiss Alps
Authors: Del Siro Chantal , Crivelli Giona , Gärtner-Roer Isabelle , Lambiel Christophe , Delaloye Reynald , Scapozza Cristian
Published: March 2024

In the current context of climate change, intact rock glaciers represent potentially important water resources in high mountain regions, regarding the storage of both liquid and solid water. In particular, water stored in ground ice could become a valuable resource in the long term, due to slower ice melt rates occurring in rock glaciers than in surface glaciers. However, the amounts of ground ice are difficult to detect, and the related processes (i.e melting and refreezing) are complicated to monitor and therefore poorly understood. In this regard, geochemistry of water emerging from rock glaciers can help gaining more insight. In this study, morphodynamic analyses of three active rock glaciers located in the Swiss Alps were therefore combined with the physico-chemical monitoring of water emerging from these periglacial landforms. The three studied rock glaciers (Monte Prosa A, Ganoni di Schenadüi and Piancabella) are located in the Lepontine Alps (Canton of Ticino) and their ground surface temperatures and kinematics are monitored since 2009. Two of them (Monte Prosa A and Piancabella) belong to the Swiss Permafrost Monitoring Network PERMOS.Changes in morphodynamics of the rock glaciers were investigated through repeated Unmanned Aerial Vehicle (UAV) and differential Global Navigation Satellite System (dGNSS) surveys during the warm season (i.e in early summer, late summer and early autumn). Intra-seasonal comparison between dense point clouds obtained through Structure from Motion (SfM) photogrammetry shows significant seasonal changes in elevation, especially a negative volumetric change in the rooting zone of two rock glaciers (Monte Prosa A and Ganoni di Schenadüi), with thickness losses ranging from about 0.15 to 0.55 m. Rooting zone also shows the largest seasonal horizontal displacements (up to 0.3 m) for these rock glaciers, obtained through image correlation. Furthermore, isotopic analysis (δ18O) were performed on water samples arising from rock glacier springs, precipitation, snowpack and seasonal ground ice, the latter sampled between blocks within the active layer. A seasonal increase in δ18O was observed in rock glacier springs, indicating a change in the water origin, from a supply fed mainly by snowmelt to a supply fed by a mixture of more 18O-enriched water. In addition, ion content of water samples collected from rock glacier springs and seasonal ground ice was also measured. Rock glacier springs show a seasonal increase in the solute export (e.g. SO42-, Ca2+ and Na+), while high concentrations of Na+, K+ and Cl- were found in seasonal ground ice samples. These first results show a clear seasonal pattern and indicate a probable influence of ground ice melting on both morphodynamics and chemistry of water emerging from the studied active rock glaciers.
Impacts of receiving international industrial transfer on China’s air quality and health exceed those of export trade
Authors: Liu Lu , Zhao Yu , Zhao Hongyan , Wang Yifei , Nielsen Chris P.
Published: March 2024

Benefiting from international economic cooperation on income, technology diffusion, and employment, China also suffers its environmental and health impacts, from both international trade (IT), as is now widely understood, and international industrial transfer (IIT), which has been largely unrecognized. Here, we develop a comprehensive framework to estimate the impacts of exporting IT and receiving IIT. We find that China’s emissions of CO2 and almost all air pollutants associated with IIT and IT together grew after 1997 but then declined after 2010, with the peak shares of national total emissions ranging 18–31% for different species. These sources further accounted for 3.8% of nationwide PM2.5 concentrations and 94,610 (76,000–112,040) premature deaths in 2012, and the values declined to 2.6% and 67,370 (52,390–81,810), respectively, for 2017. Separated, the contribution of IIT to those impacts was more than twice that of IT. Scenario analyses suggest that improving emission controls in its less-developed regions would effectively reduce the impact of economic globalization, but such a benefit could be largely offset by strengthened international economic cooperation. The outcomes provide a scientific basis for adjusting China’s strategic roles in the international distribution of industrial production and its formulation of relevant environmental policies from a comprehensive perspective.
How appropriate is the alternating block method to represent flooding from extreme precipitation events?
Authors: Jankowfsky Sonja , Sharifian Mohammad , Moges Edom , Nicotina Ludovico , Li Shuangcai , Hilberts Arno
Published: March 2024

Running inundation on a stochastic event set with thousands of events can be quite time consuming, especially if physically based methods such as the shallow water equations are used. In order to optimize runtime and to keep a high spatial resolution, event footprints are often reconstructed using return period maps. However, this means that design storm events need to be constructed for each return period which should ideally be representative for different event durations.Here, we compare the alternating block method, a popular design storm model, to actual event hyetographs from a selection of storm events in Florida. The hyetographs are input to a 10m grid-based Green-and-Ampt infiltration model which is coupled to a two-dimensional shallow-water inundation model. The difference between the alternating block method and the actual event hyetograph is measured based on the flood extent and depth.
Magnetospheric time history:  How much do we need for forecasting?
Authors: Gilmore Kendra R. , Bentley Sarah N. , Smith Andy W.
Published: March 2024

Forecasting the aurora and its location accurately is important to mitigate any potential harm to vital infrastructure like communications and electricity grid networks. Current auroral prediction models rely on our understanding of the interaction between the magnetosphere and the solar wind or geomagnetic indices. Both approaches do well in predicting but have limitations concerning forecasting (geomagnetic indices-based model) or because of the underlying assumptions driving the model (due to a simplification of the complex interaction). By applying machine learning algorithms to this problem, gaps in our understanding can be identified, investigated, and closed. Finding the important time scales for driving empirical models provides the necessary basis for our long-term goal of predicting the aurora using machine learning.Periodicities of the Earth’s magnetic field have been extensively studied on a global scale or in regional case studies. Using a suite of different time series analysis techniques including frequency analysis and investigation of long-scale changes of the median/ mean, we examine the dominant periodicities of ground magnetic field measurements at selected locations. A selected number of stations from the SuperMAG network (Gjerloev, 2012), which is a global network of magnetometer stations across the world, are the focus of this investigation.The periodicities retrieved from the different magnetic field components are compared to each other as well as to other locations. In the context of auroral predictions, an analysis of the dominating periodicities in the auroral boundary data derived from the IMAGE satellite (Chisham et al., 2022) provides a counterpart to the magnetic field periodicities.Ultimately, we can constrain the length of time history sensible for forecasting.
Reconciling climate change mitigation, biodiversity conservation and rice production through changes in water management strategies
Authors: Echeverría-Progulakis Sebastián , Martínez-Eixarch Maite , Pérez-Méndez Néstor
Published: March 2024

Tackling climate change while enhancing biodiversity without compromising production is a main goal in agricultural policy. In rice farming, water-saving irrigation techniques alternative to permanent flooding are necessary to face water scarcity and have proven effective in reducing greenhouse gas (GHG) emissions, yet potential trade-offs with biodiversity conservation are often overlooked. Here we used a field-scale experiment to compare the effects of water management strategies representing a water use gradient on i) GHG emissions, ii) the diversity of aquatic macroinvertebrate and vertebrate (fish and amphibians) communities, and iii) crop productivity. Reduced methane emissions were observed in rice fields with lowest water use when compared to fields permanently flooded, yet the effect on aquatic biodiversity and crop yield was the opposite. Through this holistic assessment approach, we were able to identify an intermediate rice water-saving irrigation strategy that conciliates climate change mitigation, biodiversity conservation and crop production in rice agrosystems.