bluuebunny/crossref_metadata_2025 huggingface dataset:
MATS satellite mission: Global patterns
Authors: Linder Björn , Megner Linda , Murtagh Donal , Christensen Ole Martin , Gumbel Jörg , Ivchenko Nickolay
Published: March 2024

MATS (Mesospheric Airglow/Aerosol Tomography and Spectroscopy) is a Swedish research satellite launched in 2022 targeting gravity wave activity in the mesosphere and lower thermosphere (MLT). Infrared measurements of MLT O2 A-band airglow conducted by the MATS satellite during February, March, and April reveal large-scale, global structures that significantly impact this region's dynamics. An analysis of atmospheric A-band emissions between 70 and 110 km reveals that atmospheric tides greatly influence the radiance produced in the airglow layer. This is evidenced by an equatorial maximum at local sunset and minima at 30°N and 30°S, which correspond to the various phases of the tides. Meanwhile - in the vicinity of the poles, westward propagating planetary waves dominate the measurements, including strong signals from the 16-day wave in the northern hemisphere, and the 5.5-day wave in the southern hemisphere. In this talk, we take a closer look at the individual measurements made by the satellite, illustrating the smaller-scale atmospheric structures they contain, as well as the global picture that the images make up together. 
Assessing river morphological changes induced by large ice-rock avalanches: The 2021 Chamoli disaster region using UAV-LIDAR data.
Authors: Kaushal Sahil , Pulpadan Yunus Ali
Published: March 2024

The Chamoli disaster of 2021 in the Rishiganga valley, triggered by a massive ice-rock avalanche, displayed a characteristic example of the complex dynamic in the glacier and fluvial systems under a warming climate. Here, we present cutting-edge UAV-LiDAR technology to examine the post-disaster morphological changes in the headwater river systems of Rishiganga, specifically focusing on river incision and channel morphological changes. Employing multi-period digital elevation models, we present the region's substantial increases in river incision and channel widening. A considerable increase in river width was also recorded following the event. Our research concludes that landslides act as a significant control of channel morphology in the Himalayan terrain. By unravelling the complex dynamics of river morphology caused by extreme events, this study contributes significantly to the literature in the context of bedrock river incision and landscape evolution.
Diffuse He degassing monitoring of Cumbre Vieja volcano, La Palma, Canary Islands
Authors: Pérez Nemesio M. , Collins Harrison , Bonomini Ida , Melián Gladys V. , Gironés Ana , Asensio-Ramos María , Padrón Eleazar , Hernández Pedro A. , Rodríguez Fátima , Padilla Germán
Published: March 2024

Cumbre Vieja volcano, at the southern part of La Palma Island, is the last stage on the geological evolution of the island, the fifth in extension (706 km2) and the second in elevation (2,423 m asl) of the Canarian archipelago. The recent volcanic activity in La Palma Island has taken place exclusively in Cumbre Vieja volcano in the last 123 ka, being the last volcanic activity the Tajogaite eruption, from 19 September to 13 December, 2021. We report herein the results of several intensive soil gas studies, focused on the non-reactive and highly mobile gas helium (He) in Cumbre Vieja. He has unique characteristics as a geochemical tracer: it is chemically inert and radioactively stable, non-biogenic, highly mobile and relatively insoluble in water. The geochemical monitoring of soil He emission at Cumbre Vieja started in 2002. Soil gas samples have been regularly collected at ~40 cm depth using a metallic probe at 600 sites for each survey and later the He content has been analysed by means of a quadrupole mass spectrometer. Spatial distribution maps have been constructed following the sequential Gaussian simulation (sGs) procedure to quantify the diffuse He emission from the studied area. The time series of diffuse He emission rate has shown significant increases before and during the occurrence of seismic swarms that took place in the period 2017-2021. During the eruptive period, a significant increase was also observed, with good temporal agreement with the increase of the volcanic tremor. Increases in diffuse He preceded peaks of diffuse CO2 emission as expected by the characteristics of these gases. The absence of visible volcanic gas emissions (fumaroles, hot springs, etc.) at the surface environment of Cumbre Vieja, makes this type of studies in an essential tool for volcanic surveillance purposes.
Rapid Estimation of Earthquake Induced Landslides using Machine Learning Models: Insights from Haiti Earthquakes
Authors: Thanveer Jiyadh , Pulpadan Yunus Ali
Published: March 2024

Strong earthquakes on mountain slopes can trigger numerous landslides, a significant secondary hazard responsible for a substantial proportion of fatalities in the affected area. In this study, we present a model framework for rapidly creating coseismic landslide probability distribution maps using machine learning models and optimal conditioning factors. To illustrate our approach, we focus on the case of the Mw 7.2 Haiti earthquake in 2021 and predict the distribution of coseismic landslides based on historical landslide data collected following the Mw 7.0 Haiti earthquake in 2010. To validate our findings, we mapped all the landslides triggered during the 2021 event. Furthermore, we conduct a comparative analysis of various landslide-conditioning factors (seismic, topographic, lithologic, and hydrological variables) in relation to the coseismic landslides occurring during both earthquake events in 2010 and 2021, to reassess the factors feed into the machine learning model. We observed noticeable differences in patterns of several conditioning factors between the two events EQIL distributions (e.g., tectonic and releif factors), but consistent similarities in other terrain factors (e.g., slope, curvature, topographic wetness index, etc.). Our Random Forest (RF) model, initially trained using the 2010 landslide inventory and 15 selected factors, effectively predicts 2021 landslides with an area under curve (AUC) score of 0.83. Improved performance is achieved when we use a reevaluated set of six factors for training, resulting in an AUC score of 0.90, with  93% of landslides falling into the high to medium probability class. These findings demonstrate the feasibility of rapidly generating highly accurate coseismic landslide distribution maps, even when there are considerable differences in key conditioning factors, highlighting the applicability of ML models to complex problems.
Advancements and Challenges in Assessing and Predicting the Global Carbon Cycle Variations Using Earth System Models
Authors: Li Hongmei , Ilyina Tatiana , Dunkl István , Spring Aaron , Brune Sebastian , Müller Wolfgang A. , Bernardello Raffaele , Bopp Laurent , Friedlingstein Pierre , Merryfield William J. , Mignot Juliette , O'Sullivan Michael , Sospedra-Alfonso Reinel , Tourigny Etienne , Watanabe Michio
Published: March 2024

The imperative to comprehend and forecast global carbon cycle variations in response to climate variability and change over recent decades and in the near future underscores its critical role in informing the global stocktaking process. Our study investigates CO2 fluxes and atmospheric CO2 growth through ensemble decadal prediction simulations using Earth System Models (ESMs) driven by CO2 emissions with an interactive carbon cycle. These prediction systems provide valuable insights into the global carbon cycle and, therefore, the variations in atmospheric CO2. Assimilative ESMs with interactive carbon cycles effectively reconstruct and predict atmospheric CO2 and carbon sink evolution. The emission-driven prediction systems maintain comparable skills to conventional concentration-driven methods, predicting 2-year accuracy for air-land CO2 fluxes and atmospheric CO2 growth, with air-sea CO2 fluxes exhibiting higher skill for up to 5 years. Our multi-model predictions for the next year, along with assimilation reconstructions, for the first time contribute to the Global Carbon Budget 2023 assessment. We plan regular updates and the involvement of more ESMs in future assessments. Ongoing efforts include implementing seasonal-scale predictions for skill improvement. Furthermore, we assess uncertainty contributions to CO2 flux and growth predictions, revealing the comparable impacts of internal climate variability and diverse model responses, particularly at a lead time of 1-2 years. Notably, the effect of CO2 emission forcing rivals internal variability at a 1-year lead time. Large uncertainties in CO2 responses to initial states of ENSO are observed, stemming from both model responses and internal variability. The challenge lies in addressing the scarcity and uncertainty of data for initialization and obtaining precise external forcings to enhance the reliability of predictions. The further advancements involve not only addressing comprehensive bias correction but also implementing statistical methods to enhance dynamical predictions.
CloudEARTHi Initiative – Reshaping Education for a Resilient Future Amidst Societal Challenges
Authors: Abu-Alam Tamer ,   CloudEARTHi consortium
Published: March 2024

In an era marked by multifaceted challenges spanning economic, social, environmental, and political realms, the CloudEARTHi initiative emerges as a transformative force in education. This initiative recognizes that the traditional educational framework requires a comprehensive overhaul to effectively address these challenges and meet the diverse needs of various stakeholders. With a focus on resilience and adaptability, CloudEARTHi is pioneering a shift in educational paradigms to better equip future generations.At the core of CloudEARTHi's approach is the involvement of diverse stakeholders in the course co-creation process. This collaborative effort ensures that education programs are not only academically robust but also practically relevant, addressing real-world issues. Recognizing the importance of soft skills, CloudEARTHi emphasizes communication, teamwork within inclusive and diverse groups, and problem-solving as integral components of its curriculum. Additionally, there is a strong focus on imparting knowledge about environmental challenges, sustainable solutions, and entrepreneurial skills, preparing students to be effective change-makers.CloudEARTHi, a unique initiative with a consortium of 23 partners from 13 European countries, encompasses higher education institutes, NGOs, businesses, and governmental sectors. This diverse collaboration facilitates a multifaceted educational approach, enriching the learning experience with various perspectives and expertise. Supported by several EU programs and initiatives, including the EIT HEI Initiative, EIT RawMaterials, Erasmus+, European Horizon (EISMEA), and HKdir (The Norwegian Directorate for Higher Education and Skills), CloudEARTHi is well-positioned to lead a revolution in education systems across Europe.This contribution aims to present the CloudEARTHi initiative, highlighting its innovative structures for involving different stakeholders in the educational process. We will discuss the initiative's progress, share insights, and invite contributions to further enhance this groundbreaking educational approach. Join us in shaping an education system that is resilient, inclusive, and capable of addressing the complex challenges of our society.
Forest inventory tree core archive reveals changes in boreal wood traits over seven decades
Authors: Bassett Kelley R. , Östlund Lars , Gundale Michael J. , Fridman Jonas , Jämtgård Sandra
Published: March 2024

Boreal forests play an important role in the global carbon cycle (C), and there is increasing interest in understanding how they react to environmental changes, including nitrogen (N) and water limitations, which may influence future forest growth and C storage. Utilizing tree cores archived by the Swedish National Forest Inventory, we measured stemwood traits, including stable N and C isotope composition, which provides information on N availability and water stress, respectively, as well as N and C content, and the C/N ratio over the period 1950–2017 in two central Swedish counties, Jämtland and Västernorrland, covering an area of ca. 55,000 sq. km (n = 1038). We tested the hypothesis that wood traits change over time and that temporal patterns would vary depending on alternative dendrochronological reconstruction methods, i.e. the established standard “single tree method” (STM) or a conceptually stronger “multiple tree method” (MTM). Averaged across all MTMs, our data showed that all five wood traits for Picea abies and Pinus sylvestris changed over time. Wood δ15N declined strongly, indicating progressive nitrogen limitation. The decline in δ13C followed the known atmospheric δ13CO2 signal, indicating there was no change in water stress. In addition, wood N increased significantly, while C and C/N ratios declined over time. Furthermore, wood trait patterns sometimes differed between dendrochronological methods. The most prominent difference was for δ15N, where the slope was much shallower for the STM compared to MTMs for both species, indicating that mobiity of contemporary N is problematic when the STM is used, leading to much less sensitivity to detect historical signals. Our study shows strong temporal changes in boreal wood traits and also indicates that the field of dendroecology should adopt new methods and archival protocols for studying highly mobile element cycles, such as nitrogen, which are critical for understanding environmental change in high latitude ecosystems.
EYE-CLIMA: A Horizon Europe project to support national inventories for emissions of climate forcers
Authors: Thompson Rona , Stohl Andreas , Peylin Philippe , Ciais Philippe , Boesch Hartmut , Aalto Tuula , Berchet Antoine , Kanakidou Maria , Winiwarter Wilfried , Peters Glen , Shchepashchenko Dmitry , Chang Jean-Pierre , Fuss Roland , Pisso Ignacio , Engelen Richard , Arneth Almut , Buchmann Nina , Reimann Stefan , Platt Stephen , Krishnankutty Nalini
Published: March 2024

National greenhouse gas inventories (NGHGIs) and Biennial Transparency Reports (BTRs) on emissions and removals are crucial elements of the Paris Agreement and its Global Stocktake. However, NGHGIs are subject to significant uncertainties, owing to uncertain emission factors and/or insufficient activity data, thus there is a need for their independent verification. One method to do this is through atmospheric inversions, which use atmospheric observations in a statistical optimization framework to estimate surface-to-atmosphere fluxes. This method of verification is referred to in the 2006 IPCC Guidelines on national reporting and in their 2019 refinement. However, atmospheric inversions have been hitherto considered too complex and inaccurate at national scales to be widely used for this purpose.EYE-CLIMA is a Horizon Europe project that aims to develop the atmospheric inversion methodology to a level of readiness where it can be used to support the verification of NGHGIs. The overarching goals are to: i) develop a best practice in atmospheric inverse modelling for estimating emissions at national scale, including a full assessment of the uncertainties, ii) develop the methodology on how to prepare sectorial emission estimates from atmospheric inversions and make these comparable to what is reported in NGHGIs, iii) work together with NGHGI agencies on projects piloting the EYE-CLIMA methodology of emissions verification and iv) develop international best practices for the quality control of NGHGIs. EYE-CLIMA covers CH4, N2O, 5 HFC species, SF6, and the black carbon (BC) aerosol. This presentation will focus on the set-up of the EYE-CLIMA project and provide an overview of the first results in support of NGHGI verification.
Health protection from heat waves in Croatia - today and in the future
Authors: Srnec Lidija , Magjarević Vjeran , Sokol Jurković Renata
Published: March 2024

Some recent research shows that the average annual excess of deaths is higher due to cold than warm events. Despite that fact, the last two decades are the warmest in history of air temperature monitoring so the long term series analyses show the increase in the frequency but also the severity of the heat waves. 

A heat wave early warning system is a very useful way of protecting human health. This system in Croatia has been operational since 2012 and thanks to it vulnerable groups of people are timely warned about the level of possible risk. In this work, we will briefly explain how Croatian early warning system works nowadays and show the change of number and level of heat wave risks through the past.  

The possible change in heat wave risk in the future will be analysed by using regional climate simulations from the EURO-CORDEX data set. Simulations will cover a set of projections on 12.5 km horizontal resolution, taking into account moderate and high RCP scenarios. The future climate will be considered for three 30-year time slices.  

The operational criteria currently used in the Croatian heat wave early warning system will be applied to the projected daily minimum and maximum air temperatures. The modelled data will be bias-corrected according to the measured data at Croatian meteorological stations. Original outputs and bias-corrected data will be analysed and compared to see which data sets approach closer to the measured data set. Historical climate risk simulated by models will be compared with issued warnings to evaluate simulations. The difference between projected and historical climate risk will be analysed by level of risk, duration, and spatial distribution.              
High spatial resolution Sea Surface Temperature data for the study of Marine Heat Waves in the souther North Sea
Authors: Alvera-Azcárate Aida , Mohamed Bayoumi , Barth Aleander , Massant Joppe , Van der Zande Dimitry
Published: March 2024

Marine Heat Waves (MHWs) are defined as discrete periods of anomalously warm water temperature at a given location. MHWs can have a huge impact on marine ecosystems, already under stress because of the effects of a warming ocean under climate change and high anthropogenic pressure. This work will assess the spatio-temporal evolution of MHWs in the southern North Sea, with an emphasis on the 2022 events. Studying the impact of MHWs on coastal marine ecosystems is currently hampered by the resolution mismatch between traditional satellite data (typically 1 km spatial resolution for SST and CHL) and species habitat/substrate. In the southern North Sea, a multitude of shallow sandbanks, sand, mud and coarser sediment substrats are for instance present, offering a multitude of habitats to different species. With ocean dynamics, and hence water mass and temperature distribution being impacted by the presence of these sandbanks, fine spatial resolution data are required for accurate analysis of the consequences of MHWs and cold spells on the ecosystem. The Thermal InfraRed Sensor (TIRS) sensor onboard the Landsat constellation provides SST at a spatial resolution of 30 m with an accuracy of 0.1 to 0.2K, and can allow the study of the evolution of small-scale dynamics in coastal regions, including the development of MHWs. However, Landsat data have a very low revisit time (7-9 days), not optimal to study specific MHW events, which can evolve on a daily basis. This work will assess the synergy between Landsat data and daily, low-spatial resolution SST data to analyse the evolution of MHWs at coastal regions. DINEOF (Data Interpolating Empirical Orthogonal Functions) will be used to merge these tow data sources and provide high spatial and temporal resolution SST data. This work is a first attempt at linking MHW variability and their consequences on marine ecosystems at very fine spatio-temporal scales, and is part of the North-Heat project. We aim at providing key insights for our comprehension of MHWs in the southern North Sea, a region where marine ecosystems are already under high anthropogenic pressure. 
Modelling the Global Uncertainty of Hydrogen Deposition
Authors: Brown Megan , Archibald Alex , Abraham Luke , Warwick Nicola , Griffiths Paul
Published: March 2024

Using hydrogen as an alternate fuel source could lead to lower carbon emissions if sourced from renewable energies. However, it can act as an indirect greenhouse gas by extending the lifetime of methane and causing stratospheric water vapour to increase. The global production and loss of hydrogen in the atmosphere are important in order to quantify its lifetime and, by extension, its global warming potential. The main sinks for hydrogen are loss through chemical reactions with OH and biological soil uptake, the latter of which accounts for approximately 80% loss and, on average, has an error range of +/-40%. Due to the wide potential range of deposition velocities and its large global impact on hydrogen, this introduces a major uncertainty to the overall hydrogen budget.Previously in the UK Chemistry and Aerosol model (UKCA), the soil uptake of hydrogen was fixed temporally and depended on land type, following the scheme by Sanderson et al. (2003). We have implemented the deposition scheme from Paulot et al. (2021) into UKCA in order to better represent the uptake of hydrogen. A wide range of soil parameters are used in the updated scheme: soil moisture, temperature, snow depth, soil carbon content, soil type, and soil saturation content, which allow for a more diverse and dynamic range of deposition velocities. These results from UKCA are evaluated against previous global hydrogen budgets and verified against hydrogen observations from the National Oceanic and Atmospheric Administration.The calculation of hydrogen deposition velocity onto soil is independent of atmospheric hydrogen, and, as a result, can be calculated offline. We use data from CMIP6 simulations as inputs to calculate a range of global hydrogen deposition velocities across multiple future projections using a range of different deposition models. The different uncertainties associated with models (hydrogen deposition and climate models) natural variation, and future scenarios can be isolated. Fluctuations in deposition and variation through time can be analysed to assess the which factors have the greatest contribution to the hydrogen deposition velocity uncertainty.
Shear heating along subduction zones and thermal structure in the domain of deep slow earthquakes: evidence from the exhumed subduction-type Sanbagawa metamorphic belt, SW Japan
Authors: Wallis Simon R. , Ishii Kazuhiko , Koyama Yukinojo , Nagaya Takayoshi
Published: March 2024

Deep slow earthquakes are commonly observed downdip from the seismogenic zone in relatively warm subduction zones. Most of these events occur close to the Moho depth of the overriding plate at depths of 30–40 km. Slow earthquakes show characteristics that can be related to both brittle and ductile behavior and their occurrence is thought to be closely related to the brittle-ductile transition. There is also good evidence that slow earthquakes develop in regions of high fluid pressure. The temperature of subduction zones is an important control on the location of the brittle-ductile transition and the release of fluid and healing of cracks along which fluids may move. However, temperature estimates along subduction zones are subject to considerable uncertainty. One of the main uncertainties is the amount of shear heating; many thermal models of subduction zones assume such shear heating is negligible. The Sanbagawa metamorphic belt of Southwest (SW) Japan formed along an ancient subduction boundary and now includes slivers of mantle wedge-derived serpentinite which are in direct contact with metasedimentary rocks derived from the subducted oceanic plate. These areas can be related to the ancient subduction plate interface. P-T paths from petrological studies combined with information on ancient plate reconstructions and thermal modelling suggest significant shear stresses developed along the subduction boundary and these strongly affect the thermal structure. Rocks originally located deep in subduction zones can record information about deformation processes, including shear stress. The estimated shear stress is likely to be representative of shear stress experienced over geological timescales and be suitable to use in subduction zone modelling over time scales of millions to tens of millions of years. Stress estimates based on quartz microstructure yield differential stresses of 30–80 MPa at depths close to the Moho of the overlying plate. Such stresses are compatible with the estimates from thermal modelling and imply shear heating needs to be considered when estimating the thermal structure in the domain of slow earthquakes.
Improving the in situ observation-based long-term record of stratospheric age of air 
Authors: Laube Johannes , Atlas Elliot , Blazaki Kyriaki , Chen Huilin , Engel Andreas , Heikkinen Pauli , Kivi Rigel , Tuffnell Elinor , Wagenhäuser Thomas , Rolf Christian
Published: March 2024

Stratospheric mean age of air is an important metric and much-used proxy for the speed of the residual overturning circulation in the stratosphere. Much effort has been put into better constraining observation-based estimates of age of air over the past two decades. Yet substantial uncertainties remain for some aspects such as the long-term evolution, especially at higher altitudes that are hard to reach for most in situ-measurement platforms.We here present a newly derived age of air data set, which is based on high precision measurements of inert trace gases that were derived from a) AirCore samples from multiple weather balloon-based deployments since 2017 (updated from Laube et al., 2020), and also b) recently collected as well as archived reanalysed air samples from high altitude aircraft and large balloon campaigns between 1976 and 2017. Utilised trace gases include SF6, C2F6, C3F8, CHF3 (HFC-23), and C2HF5 (HFC-125), all of which have been proven to be suitable as age tracers (Leedham Elvidge et al., 2018). We evaluate the uncertainties connected to the trace gas measurements as well as the derivation of the mean age of air, and compare our estimates to published data sets such as the one from Engel et al. (2017). ReferencesEngel, et al., Atmos. Chem. Phys., 2017, https://doi.org/10.5194/acp-17-6825-2017.Laube et al., Atmos. Chem. Phys., 2020, https://doi.org/10.5194/acp-20-9771-2020.Leedham Elvidge et al., Atmos. Chem. Phys., 2018, https://doi.org/10.5194/acp-18-3369-2018.
Radiocarbon signatures of dissolved black carbon in early winter water masses from the Beaufort Sea
Authors: Speidel Linn , Haghipour Negar , Blattmann Thomas , Bröder Lisa , Lattaud Julie , Coppola Alysha I. , Eglinton Timothy I.
Published: March 2024

Black carbon (BC) is a fraction of organic carbon resulting from the incomplete combustion of biomass and fossil fuels. The production and fate of BC is a topic of great interest in the context of ongoing climate change, as the intensity and severity of fires is increasing. The recalcitrant nature enables BC to buffer these changes by removing biomass-derived carbon into longer cycling pools. BC is mainly produced on land and a portion is transported in both particulate and dissolved form by the rivers to the oceans. Dissolved BC (DBC) cycles on millennial timescales, thereby storing BC as fraction of Dissolved Organic Carbon (DOC) in the marine DOC pool before deposition to sediments or complete degradation. However, there is currently limited information on the cycling, transport and evolution of modern riverine DBC, and how it contributes to the deep ocean DOC pool.The arctic and boreal regions are well recognized as a nexus for climate change, given amplified rates of change in average temperatures and summer precipitation, which exacerbate carbon cycle feedbacks, including enhanced BC production by intensified wildfire seasons. The Beaufort Sea in the Arctic Ocean is composed of different water masses, with Pacific water masses entering from the Chukchi Sea, and arctic rivers - in particular the Mackenzie River - being the major source of freshwater that delivers both terrestrial DOC and DBC. Presently, information on the sources and fate of BC in the Arctic Ocean remains sparse.Here, we report DBC concentrations and Δ14C values in the Beaufort Sea during early winter conditions. Distinct water masses were sampled, including the outflow of the Mackenzie River and the Pacific water jet on the shelf break, during two cruises in 2021 and 2022 that spanned the coast of north Alaska to the Amundsen Gulf. Preliminary radiocarbon results show that DBC on the shelf break is up to five millennia old. We discuss our findings in the context of regional hydrography and carbon cycle processes.
An overview of Lake Urmia: a dying lake in Iran
Authors: Baghaei-Yazdi Namdar , Mohseni Ali , Fallahi Esmaeil
Published: March 2024

This paper is a literature review of published papers on Lake Urmia. The authors have conducted a literature search on the status of this dying lake, causation of failure, and potential of recovery.Lake Urmia (LU) is as the largest endorheic and hypersaline lake in Iran and one of the largest saltwater lakes in the world. Anthropogenic drought, along with natural resources mismanagement based on political ideology of Islamic Republic of Iran are the preeminent factors behind the disappearance of LU.There is a growing interest in restoration of saline lakes around the world. Eco-conscious people around the world have been concern with drying lakes of the world. Likewise in Iran the number of concern scientists and Eco-conscious public has been increasing as well. The outcry for restoration of the drying lakes inundated the scientific communities for restoration of the drying lakes. The published data indicate that LU had the least recorded shrinkage between 1987 to 2000 with less than 2% of the lake surface water area. From 2000 to 2010 LU started shrinking with rapid pace to 28% of the surface area and from 2010 to 2014. The 2 chief contributing factors to the LU shrinkage are the construction of 30 operating dams and 16 more under construction by the IRI government and the second factor is licensing the drilling of 88000 water wells in and around the lake Urmia. After years of the public outcry, finally the Government sanctioned the restoration of LU in 2014. As a part of the restoration process, the researchers using the spatio-temporal technology to detect the land cover changes and salinization progress in Urmia Lake Basin (ULB) during  2014 to 2019. The available data indicates that the area of irrigated lands around the lake increased from 1265 km2 in 1975 to 5525 km2 in 2011, resulting in disappearing of the water surface area of UL from 5982 km2 in 1995 to 586 km2 in 2014 with increased salinization in the basin of LU.  According to most of the published investigative studies to the cause and effect of the shrinkage of the LU, the natural drought and climate changes were not the main causes of the lake LU shrinkage. We believe, restoration of the lake Urmia demands a multidisciplinary approach through integration of marine biologists, ecologists, botanists, agricultural scientists, engineers, epidemiologists, chemists, geologists, management and governmental policies experts, under the supervision and inspection of the United Nations Environmental agencies.
MARSIS data as a New Constraint for Phobos’ orbit 
Authors: Desage Léopold , Herique Alain , Lainey Valery , Kofman Wlodek , Cicchetti Andrea , Orosei Roberto
Published: March 2024

Phobos’ orbit is currently known down to a precision of 300m, mostly directed along its track. It has mainly been determined with imagery, and more recently with the Super Resolution Channel of the HRSC camera onboard Mars Express (MEX). This method is associated with an error mainly normal to the plane of imagery. By dynamical constraints, Phobos’ trajectory determination error is mainly spread along its orbit. In order to refine the orbitography and reduce the range error of the measurements, we propose to use data from the MARSIS radar onboard MEX. To do so, we perform a SAR synthesis on the MARSIS data in order to locate the radar echoes in a range/along-track plane. For every one of the 35 datasets at our disposal measured between 2008 and 2021, we also perform a coherent simulation using a Phobos shape model by Willner et al. (2014), and apply the SAR synthesis the same way we did for the MARSIS datasets. Given the geometry of our simulations and the SAR synthesis, the simulated radargrams are not sensitive to a range error of a few km in MEX’s trajectory, they can therefore be taken as reference points. We measure range errors between simulations and MARSIS data, distributed around +1km, with a standard deviation of 350m. The measurements being spread all around Phobos, the most probable cause for the non-zero average of the offsets measurements is an instrumental delay. After subtracting this average from the measurements, we estimate the offset that Phobos would have along its track to create this standard deviation. We find that this offset is of about 100m before 2017, and that the estimated value is rising linearly after this date to reach about 1.3km in 2021, date of our last observation. Since 2017 is the date of the last control point of the NOE-4-2020 ephemeris used for this study, our measurements exhibit a significant drift after this time period suggesting that there may exist a source of inaccuracy in the Phobos ephemeris. This study shows that radar data can be used as control points for the orbitography.
Vertical fluxes in subpolar eddies from a high-resolution, multiplatform experiment in the Labrador Sea
Authors: Dilmahamod Ahmad Fehmi , Karstensen Johannes , Horstmann Jochen , Krahmann Gerd
Published: March 2024

Mesoscale structures are key dynamical features of the ocean. They are associated with a variety of short lived and small-scale dynamics linked to physical, biological, and chemical processes at the submesoscale, such as cascading energy, impacting ocean stratification, and guiding ocean carbon and oxygen uptake. In the high latitudes, the spatial extent of the mesoscale is only tens of kilometres, making it challenging to observe the submesoscale processes. In August-September 2022, an extensive submesoscale-resolving multiplatform experiment was conducted across an Irminger Ring in the Labrador Sea. The experiment leveraged two underwater electric gliders equipped with nitrate, microstructure shear, chlorophyll fluorescence, oxygen, and turbidity sensors, operated in concert with a variety of ship operated instruments including underway-CTD’s, a moving vessel profiler, Thermosalinograph, ADCPs and a X-band radar system. Observations were acquired both, along the peripheries and within the core of the eddy, and offered insight into submesoscale dynamics of the ring. Making use of nearly concurrent turbulence and nutrients observations, we estimated the vertical flux pattern across the eddy’s frontal and interior regions. From the recorded and expected glider vehicle motion a vertical water velocity could be inferred and compared with the nutrient flux pattern. The stability of the ring was tracked with surface drifters, for weeks after the ship and glider survey ended, and a link between the disintegration of the ring and an atmospheric event was investigated
A decade of multibeam bathymetric mapping: Implications and lessons learned from (peri-)Alpine lakes in Switzerland
Authors: Kremer Katrina , Fabbri Stefano , Hilbe Michael , Anselmetti Flavio S.
Published: March 2024

Studying the morphology of the landscape is crucial for understanding the processes that shape the Earth’s surface. In subaqueous environments, where direct observations are challenging, bathymetry-derived terrain models are the fundamental form of geomorphological data. Over a century ago, Switzerland initiated systematic bathymetric surveys under the federal "Siegfried Map" project, marking an effort to explore the subaquatic morphology of perialpine lakes. These early studies laid the groundwork for subsequent research on the subaqueous landscape in Switzerland. The early bathymetric surveys in Switzerland focused on documenting the general shape of deep basins and discovering features on lake floors such as channel levee complexes and sublacustrine moraine ridges. These observations formed the basis for early theories on the age of the last glaciation and the existence of turbidity currents in lakes.Recent advances in multibeam swath bathymetry systems combined with differential GNSS location services dramatically improved survey efficiency as well as spatial and vertical resolution by several magnitudes, generating new findings with every surveyed lake. Apart from the reconnaissance of the overall basin shape, the detailed geomorphologic mapping led to the discovery of various subaquatic features, such as landslides and rockfalls, glacial features, pockmarks, channel and canyon systems, fault structures, and prehistoric and historic human impact. These findings had significant implications for evaluating natural hazards caused by earthquakes, floods, and tsunamis. Detailed glacial imprints became suddenly visible in high-alpine proglacial lakes, revealing the recessional behavior of glaciers. Mapping the source area of mass movements on the lake’s slopes represents the base for understanding lacustrine tsunamis and their modeling. Subaquatic canyons of deltaic systems often extend further into deeper waters than anticipated, promoting accelerated transport of coarse-grained sediments into the deepest parts, typical target areas for major drilling campaigns. Submerged traces of prehistoric settlements revealed unexpected chapters of human activities. Therefore, no drilling effort should be planned without a detailed lake floor map.In this contribution, we will outline lessons learned from these surveys of 22 lake systems across Switzerland since 2007, summarize key findings, and review the implications of the technology on the limnogeological community. We will also glimpse the future and explore what to expect from ongoing 4D-bathymetric mapping campaigns.
CNES Earth Observation Programme and our vision for the monitoring of the water cycle
Authors: Le Gac Sophie , Cherchali Selma , Carbonnière Aurélien , Deschamps Adrien , Faugere Yannice , Maisongrande Philippe , Sylvestre-Baron Annick
Published: March 2024

The French Space Agency, Centre National d'Etudes Spatiales (CNES), is responsible for shaping and implementing France’s space policy at national, European and international levels. Among its five key domains (launchers, science, Earth observation, telecommunications and defence), the Earth Observation programme is a fundamental pillar which covers a full scope of activities: from science and technology needs and priorities to the development of applications and services, with a strong core in infrastructure and data management.Earth Observation (EO) is becoming increasingly accurate and essential to tackle major challenges for the future: advancing our understanding of the functioning of the Earth system, in particular the water, energy and carbon cycles, understanding and assessing climate change and its effects, and the impact of humans on the environment. This research and the development of new space missions both contribute to satisfying major societal needs for up-to-date and qualified environmental information. CNES, along with its national and international partners, is working to develop and to renew the space infrastructure needed for continuous innovation to address those needs and, on the other hand, support new actors to develop the market.In this presentation, we will show how CNES EO program addresses the challenges of the monitoring of the water cycle, from the science and climate drivers to the downstream applications, with a focus on current satellite missions’ achievements such as SWOT. Ongoing developments and future missions addressing the different components of the water cycle will also be presented: Trishna, a thermal-infrared mission to measure surface temperature of land surfaces and coastal strips at high temporal and spatial resolution; The Atmosphere Observing System AOS, a mission to examine links between aerosols, clouds, convection and precipitation. C3IEL, an innovative mission dedicated to water vapor, convective clouds and lightning, and their impact on climate. ODYSEA, a mission to understand ocean currents and winds, and the sea-air interactions. SMASH, a high-revisit altimetry mission designed to provide river and lakes water level.
Exploring the relationship between urban morphology types and household-level flood vulnerability profiles in Ho Chi Minh City
Authors: Tu Jiachang , Reimuth Andrea , Garschagen Matthias
Published: March 2024

There is rising discussion focused on the ways in which urban growth and expansion, often into flood-prone areas, takes effect on the exposure and vulnerability profiles of the respective households. In order to drive city-wide and regional analysis, remotely sensed urban structure types are increasingly being used as a proxy for socio-economic characteristics. However, whether and how urban structure types in fact match the nuanced realities of socio-economic exposure and vulnerability to floods remains largely unclear. Resolving this question is of particular relevance for improving flood risk assessments in rapidly growing coastal cities with a high hazard exposure. We therefore use Ho Chi Minh City in Vietnam as a case study to develop a detailed composite indicator index for measuring the exposure and vulnerability at household level in flood-affected parts of the city, based on household survey data. We then correlate this index to urban structure types to see whether morphology characteristics map against socio-economic vulnerability and exposure profiles. In order to allow for an assessment of temporal trends, data from a repeated survey (two years after the first) is used to examine dynamics in exposure, vulnerability and urban development.Our research yields a number of key results (Tu et al., forthcoming): First, household vulnerability is not necessarily correlated to flood exposure. Second, the vulnerability and flood exposure levels of households are differ along an urban, peri-urban and rural gradient. Third, the exposure and vulnerability profiles only partly correlate with the urban structure types, but a certain mapping can be done with a reasonable uncertainty bandwidth in order to drive future modeling forward. These findings not only shed light onto spatial vulnerability patterns in HCMC but also on methodological advances in the field of city-wide risk and adaptation modeling. These lessons and their transferability to other coastal cities with similar adaptation pressures but different morphology and vulnerability profiling will be discussed.
IODP Expeditions 384/395C/395: Reykjanes Mantle Convection and Climate. Preliminary results
Authors: Briais Anne , Parnell-Turner Ross , LeVay Leah ,   Expedition 395 Science Party
Published: March 2024

International Ocean Discovery Program Expeditions 384, 395C and 395 investigated the interactions between variations in the Iceland hotspot activity, ocean crust formation at the Reykjanes Ridge, ocean circulation, and climate in the North Atlantic, and sediment drift deposition on the flanks of the mid-ocean ridge. Variations in crustal production along the Reykjanes Ridge produced V-shaped ridges and troughs located on the flanks of the mid-ocean ridge, and the role of the Iceland hotspot in their generation is debated. Changes in hotspot activity, and therefore in the associated dynamic topography, likely influenced the depth of the oceanic gateways formed by the Greenland-Scotland Ridge between the North Atlantic and the Norwegian and Arctic Seas. Such variations might thus have controlled the strength of cold, deep water currents, and the accumulation rate of sediment drifts on the flanks of the ridge: Björn and Gardar drifts on the eastern flank and Eirik drift to the west. Expeditions 384 in 2020, 395C in 2021, and 395 in 2023 collected cores from a transect of five drill sites along a plate-spreading flowline spanning seafloor ages from 2.8 to 32 Ma and crossing Björn and Gardar drifts on the eastern ridge flank, as well as a sixth site along the eastern Greenland margin crossing Eirik drift. Combined, over 400 m of oceanic basalt and over 5.8 km of sediment core was recovered, including continuous records through key Pleistocene and Pliocene sequences, and a unique record of progressive basalt alteration. Here we present preliminary results of the expedition, featuring new insights into crustal accretion variations through time, constraints on the onset of sedimentation at Björn, Gardar and Eirik contourite drifts, and new records of climatic cycles on thousand-year timescales. These sites also provide a unique view on how crust interacts with fluids and sediment over millions of years, while in-situ samples obtained from the cores yield insights into chemical exchanges and microbial systems in the ocean, sediment, and crust. The vast amount of sediments, basalts and measurements collected during Expeditions 384, 395C and 395 will provide a major advance in our understanding of mantle dynamics and the linked nature of Earth’s interior, oceans, and climate.
Gridded datasets of climate indices: comparison of two approaches
Authors: Tilg Anna-Maria , Habibi Maral , Chimani Barbara , Greilinger Marion
Published: March 2024

Gridded data is highly appreciated for many climate related applications due to their spatial information compared to single station locations. The quality and additional value of a gridded dataset is depending on the method itself and on the amount of additional information, e.g. topographical data, used for the interpolation. Furthermore, there is an ongoing discussion on the implications of using gridded datasets of primary climate parameters like temperature or precipitation to derive gridded datasets of climate indices. Within the project SDGHUB (https://www.sdghub.at/), we are exploring the influence of different approaches on the final gridded climate index dataset.  The focus is on the frequently used climate index of hot days (days with a maximum air temperature above or equal to 30 °C). In the first approach the hot days were computed from the gridded climate dataset SPARTACUS (Hiebl and Frei, 2016), while in the second approach the hot days were directly interpolated considering station values. SPARTACUS is a national gridded dataset of Austria, available on a daily basis with a 1 km-spatial resolution via the DataHub of GeoSphere Austria (https://data.hub.geosphere.at/). It covers the period from 1961 onwards and includes the parameters of maximum, minimum and mean air temperature and rain amount.  For the second approach the efficacy of several geostatistical interpolation methods, including Kriging with External Drift (KED), Ordinary Kriging (OK), and Regression Kriging (RK), with a particular emphasis on their ability to represent the spatial variability of hot days was explored. The comparison showed that KED provides the best results, as the complex terrain in Austria can be considered best. Therefore, this method was used for further analysis. To further improve the interpolation results of KED, different data transformations were tested, with the square root transformation emerging as the most effective one. As for SPARTACUS, the direct interpolation was done on a 1 km-scale for Austria.To evaluate the performance of the two respective approaches a cross-validation is applied.The presentation will include information on the interpolation methods and provide insights into the evaluation and differences of the two datasets as well as the effect of station density. The final dataset of hot days will be available via the DataHub of GeoSphere Austria with a monthly, seasonal and annual resolution. ReferencesHiebl J, Frei C (2016) Daily temperature grids for Austria since 1961 – concept, creation and applicability. Theor Appl Climatol 124:161–178. https://doi.org/10.1007/s00704-015-1411-4 AcknowledgementThe project SDGHUB is funded by the Austrian Federal Ministry for Climate Action, Environment, Energy, Mobility and Technology (BMK) via the ICT of the Future Program - FFG No 892212.