bluuebunny/crossref_metadata_2025 huggingface dataset:
Unveiling the Crucial Role of Emissions Inventories from Solid Waste Burning in Air Quality Management across Diverse LMICs; A Case of Nairobi City
Authors: Apondo William , Mwaniki George , Kennedy John , Murgor Ivy , Munyambu Purity
Published: March 2024

Air pollution poses a significant environmental risk in low- and middle-income countries (LMICs), characterized by diverse pollution sources and complex atmospheric processes. Specifically, the city of Nairobi grapples with air quality challenges, generating approximately 2800 tons of solid waste daily, with 75% undergoing collection and the remaining 700 tons (3.9KG/person/year) being openly burnt. Our study underscores the crucial role of bottom-up emissions inventories, particularly those associated with solid waste burning, in quantifying emissions and guiding evidence-based air quality management strategies within the context of data-scarce LMICs. Leveraging the Solid Waste Emission Estimation Tool (SWEET), our estimations encompass Methane (CH4), Black Carbon (BC), Particulate Matter (PM), oxides of Nitrogen (NOX), and other pollutants from municipal solid waste sources. Our baseline scenario, established for the year 2022, is compared with successive five-year alternative scenarios. Preliminary findings indicate alarming emissions, with around 5.2 million metric tons of PM10, 3,400 metric tons of SOx, and 300 million metric tons of Black Carbon annually from open burning under the business-as-usual scenario. Notably, implementing emission reduction strategies, such as the closure of official dumping site, exhibits promising outcomes. Projected reductions include up to 15% in Methane emissions by 2031 (Scenario1) and a substantial 75% reduction by 2033 (Scenario2). Furthermore, SOx, CO2, and PM emissions are anticipated to decrease by over 90% under these scenarios. Strategically reducing waste burning activities, coupled with measures like cutting the garbage truck fleet by 50%, could yield drastic emission reductions. Our findings emphasize the potential for impactful emissions reduction benefits in addressing open waste burning, an often overlooked source contributing significantly to air pollution in rapidly developing cities like Nairobi. The discussion highlights the importance of a bottom-up approach in developing emissions inventories to comprehend the impact of waste burning on overall city emissions reduction goals and incorporating Gender dynamics.
InsegnaciETNA 2023
Authors: Larose Carole , Berenguer Jean-Luc
Published: March 2024

The 2023 edition of the Insegnaci Etna School brings together a number of schools from Eastern Sicily. It aims to teach various aspects of geosciences directly in the field, not only about the nearby Etna volcano, but also about earthquakes, tsunamis, meteorology, geo-environment and the relationships between all these elements and the inhabitants of this area. There were scientific conferences on Etna's eruptions, active faults, earthquakes and ground deformation and also presentations by students from local schools. There were three laboratories where teachers can carry out various practical didactic activities on earthquakes, seismic data analysis, the "Sismobox" experiments, and satellite images analysis. And finally, there was an excursion to the slopes of Etna above Bronte with the support of the Bronte section of the Club Alpino Italiano.I am going to detail one of these laboratories organised by EduMed an educational observatory supported by the University of the Côte d'Azur in Nice, France.  This observatory and its European partners have extended the scope of their educational activities to all aspects of geosciences and geohazards in the Mediterranean.In this workshop, the main goal is to allow teachers to analyse data from seismometers stations in Etna’s area.
Assessing the effects of surface ozone on forest GPP: a vegetation model approach using JULES
Authors: Vieira Inês , Meunier Félicien , Sitch Stephen , Brown Flossie , Duran Rojas Carolina , Gerosa Giacomo , Jansseans Ivan , Boeckx Pascal , Bauters Marijn , Verbeeck Hans
Published: March 2024

Tropospheric Ozone (O3) is a secondary pollutant known for its positive radiative forcing and detrimental effects on air quality, human health, and ecosystems. In plants, O3 acts as a strong oxidant, affecting cellular and molecular processes, e.g. modifying rubisco activity, reducing stomatal conductance, and inducing early leaf senescence. This study aims to evaluate the effects of O3 on Gross Primary Production (GPP) at six forest sites: five European sites (Belgium, France, Finland and Italy) and one tropical site in the Congo Basin. We employed a modelling approach, contrasting simulations of GPP with and without the influence of O3 using the Joint UK Land Environment Simulator (JULES), a land surface model used to study soil-vegetation-atmosphere interactions. The JULES model was calibrated for each site, adjusting key parameters, using historical climate data and soil properties to align with each location's specific environmental and vegetation characteristics. Therefore, we forced the model using measurements of local tropospheric O3, CO2, and meteorological variables. We conducted two simulations for each site: one representing the existing O3 levels observed at each site and another under O3-free conditions. This comparative approach enabled us to isolate the specific effects of O3 on GPP to quantify this effect. Our findings reveal a difference in the sensitivity of the contrasting forest ecosystems to O3 exposure. The correlation values between modelled GPP with O3 and observed GPP vary between 0.786 in Castelporziano, Italy and 0.933 in Hyytiälä, Finland. Consequently, the European sites, encompassing a range of climatic and ecological conditions, displayed diverse responses to O3, and the GPP reduction varies along the different sites. The GPP reduction due to O3 exposure varied across sites, ranging from -1.52% in Hyytiälä, Finland, to -9.79% in Castelporziano, Italy. This study shows the necessity of long-term monitoring datasets combined with process-based models to understand better the O3 impacts at several ecosystems.
A Unified Representation of Subgrid Convection in NOAA’s Unified Forecast System
Authors: Bao Jian-Wen , Michelson Sara , Li Haiqin , Park Sungsu
Published: March 2024

It remains challenging to represent subgrid convection in weather and climate models at horizontal grid resolution across the gray zone, in which convective clouds are only partially resolved by the model dynamics and it is required for the representation of subgrid convection to have a generalized transitional behavior as the model’s horizontal resolution varies.  A practical approach for such a representation is to scale the eddy transport of physical properties from a conventional convection parameterization scheme by a quadradic function of the fractional area covered by convective updrafts in the grid cell (Arakawa and Wu, 2013).  Despite this approach’s popularity, its generalization is limited theoretically by the fact that the coarse-graining statistical analysis that gave rise to the approach involved only an idealized scenario of deep convection in quasi-equilibrium.  Additionally, when applying this approach, there is a theoretical ambiguity associated with the validity of conventional convection parameterizations for a fractional area covered by convective updrafts in the grid cell that is not close to zero.An alternative approach for subgrid convection representation across the gray zone is to apply a unified plume scheme that treats subgrid convection as nonlocal asymmetric eddies due to unresolved convection relative to the grid-mean vertical flow (Park, 2014).  This unified plume scheme represents unresolved convection relative to the grid-mean vertical motion without relying on quasi-equilibrium assumptions in conventional convection parameterizations.  Its generalized transitional behavior across the gray zone is naturally controlled by the size of the plumes representing unresolved convection that varies with the model’s horizontal resolution.  It simulates all unresolved convective transport of atmospheric properties within a single steady framework, allowing multiple convective plumes.  It also includes the prognosis of unresolved cold pool and convection organization within the planetary boundary layer.  The unified plume scheme circumvents the theoretical limitation and ambiguity of the above approach based on conventional convection parameterization.  It also rectifies the lack of plume memory across the time step in conventional convection parameterizations.This presentation will focus on an ongoing effort to experiment with the alternative unified approach for representing subgrid convection across the gray zone in NOAA’s Unified Forecast System.  Results from 1-D and 3-D case studies will be shown to highlight the advantage of the unified plume scheme.References:Arakawa, A., and C.-M. Wu, 2013: A unified representation of deep moist convection in numerical modeling of the atmosphere. Part I. J. Atmos. Sci., 70, 1977–1992.Park, S., 2014: A unified convection scheme (UNICON). Part I: Formulation. J. Atmos. Sci., 71, 3902–3930.
Assessment of climate change at near-term (2020-2040) over Northern Europe through internal variability storylines
Authors: Cassou Christophe , Line Aurelien , Msadek Rym
Published: March 2024

It is well established that internal variability arising spontaneously from the chaotic nature of the climate system can amplify or obscure anthropogenically-forced signals, especially at near-term and at regional scale in the extratropics. In this talk, we focus on Northern Europe (NEU) winter climate changes over the 2020-2040 period and propose a set of internal variability storylines (IVS) to tackle related uncertainties. IVS are built from the combined evolution of the North Atlantic Oscillation (NAO) and the Atlantic Meridional Overturning Circulation (AMOC) diagnosed as drivers of variability for temperature over NEU.We first show, based on a large ensemble of historical-scenario simulations from CNRM-CM6-1, that, depending on the near-term [AMOC-NAO] doublet evolution, anthropogenically-forced changes can be either considerably amplified with much warmer-wetter mean conditions, almost doubled, or considerably masked with marginal warming and unchanged mean precipitation with respect to present day. We then provide evidence for the robustness of our results by using large-ensembles from several models which ultimately allows assessing the full range of uncertainties for near-term climate change.We finally use the 2010 severe winter case as an illustrative example of the added-value in expressing climate change knowledge in a conditional form through IVS to plan at best climate-related risks and local adaptation strategies at near term. Reframing the uncertain climate outcomes into the physical science space through IVS grapples the complexity of regional situations; it is also informative to more efficiently communicate towards the general public as well as for climate literacy in general.
The Great Fuel Moisture Survey: developing fundamental wildfire science and sustainable community owned agency in traditionally non-fire prone societies
Authors: Kettridge Nicholas , Ivison Katy , Crawford Alistair , Clay Gareth , Belcher Claire , Graham Laura , Little Kerryn
Published: March 2024

New fire vulnerable communities are emerging in traditionally non-fire prone regions of the world. But these communities are often largely unaware of the developing threat and do not hold the core wildfire knowledge to galvanise collective community-based action to mitigate the risk. Furthermore, we urgently require knowledge of fuel moisture dynamics and flammability of fuels in such regions to provide accurate assessments of fire danger at the national scale. Here we characterise the moisture content and flammability of heather through engaged environmental science, demonstrating the potential of the approach to develop a public consciousness and knowledge of wildfire within communities. Fuel sampling kits were sent to 150 samplers who collected ~1000 vegetation samples across the UK (from Land’s End to John O’Groats) over a period of two days during a single period of high fire danger. The validity of the volunteer approach for collecting high quality fuel moisture data was also assessed from the analysis of a separate ~1500 samples collected by 17 samplers in a single test plot. The approach provides a simple nationally available entry point for residents traditionally unaware of both the wildfire risk and the management of their community for wildfire mitigation. Empowering samplers offers potential future opportunity to create meaningful local datasets, to build communities, and in doing so give a strong voice to residents in regional and national policy discussions.
Combination of GRACE/GRACE-FO and CryoSat-2 data resolves Glacial Isostatic Adjustment spatially and temporally in the Amundsen Sea Embayment, West Antarctica
Authors: Willen Matthias O. , Wouters Bert , Broerse Taco , Buchta Eric , Helm Veit
Published: March 2024

An effective spatial resolution of a few hundred kilometres, typically assessed for mass variations derived from GRACE/GRACE-FO data, is a major limitation for the rigorous investigation of local causes of mass variations. This is crucial for analyzing mass changes of the West Antarctic Ice Sheet, which is one of the tipping elements in the Earth’s climate system. In this region, ice mass changes occur on spatial scales smaller than the typical GRACE/GRACE-FO resolution. Furthermore, this is also the case for the solid-Earth deformation induced by ice load changes, which in turn can affect the glacier flow. Especially in the Amundsen Sea Embayment, mass changes due to the ongoing Glacial Isostatic Adjustment (GIA) have been postulated to vary on spatial scales smaller than 200 km and to feed back significantly on ice flow dynamics. Here, we present results from a data combination approach with a focus on the Amundsen Sea Embayment, West Antarctica. This approach utilizes data from GRACE/GRACE-FO and CryoSat-2 satellite altimetry with regional climate and firn model results over a time span of 10 years from 2011 to 2020. Improved GRACE/GRACE-FO gravity-field processing and a study area in a high latitude region, where the signal-to-noise is high, benefit a high spatial resolution of the results. One processing step is the smoothing of the input data sets in order to unify their different spatial resolution. We find a best fit of the combination results with independent GNSS observations by applying a Gaussian smoother of 135 km half-response width. The weighted rms difference is 3.8 mm/a in terms of estimated bedrock motion. It is almost twice as large when the input data sets are smoothed with a 300 km half-response filter. The determined effects of solid-Earth deformation may be a useful boundary information for GIA modelling in this region, e.g. for testing rheological models or (centennial) glacial histories.
Effects of 2018 wildfire on soil properties in a peatland within the Peak District National Park (central England)
Authors: Marfella Luigi , Ashby Mark A. , Hennessy Georgia , Marzaioli Rossana , Rutigliano Flora A. , Glanville Helen C.
Published: March 2024

Peatland soil is a valuable component of natural capital by constituting the largest terrestrial carbon sink (~30% of the global soil carbon) and an essential freshwater source. Despite covering only ~3% of the Earth’s surface, peatlands provide crucial ecosystem services i.e. water-quality improvement and climate regulation by storing carbon in peat. However, peat degradation due to anthropogenic activities (e.g. drainage) as well as global climate change exposes this ecosystem to fire risk.This study assessed the medium-term (~5 years) impacts of the 10 August 2018 wildfire within The Roaches Nature Reserve. This area spans the southeastern sector of the Peak District National Park and Special Area of Conservation (SAC-UK0030280). According to the Staffordshire Wildlife Trust (responsible authority for Reserve management), the human-caused fire broke out in a wooded area and aided by wind, spread to the peatland. Here, we integrated soil analyses and vegetation surveys of a burnt and unburnt area i) to assess possible correlations between soil biogeochemical properties and vegetation cover with ii) remote sensing to collect data on fire severity exploring temporal and spatial wildfire impacts.Processing of satellite imagery highlighted a high-severity fire impact within the perimeter of the burned area, which predicts alteration of soil characteristics. Preliminary outcomes on the soil indicated deacidification and reduced water content in the burned peat remains 5 years post-fire.Given that global peatland conservation is an important tool for addressing climate-change, this research appears necessary to develop effective management strategies, including rewetting of peatlands postfire.
A process-based water stable isotope mixing model for plant water sourcing
Authors: Si Bing , Si Eric , Fu Han
Published: March 2024

Stable isotopes of hydrogen and oxygen in water are common tools for investigating water uptake apportionment, but many of the existing methods rely on simple linear mixing approaches that do not mechanistically incorporate additional information about site physical properties and conditions. Here, we develop a 'physically based root water uptake isotope mixing estimation' model (PRIME) that combines a continuous and parametric probability density function for root water uptake with site physical data in a process-based linear mixing framework. To demonstrate the application of PRIME, water uptake patterns of boreal forest Pinus banksiana trees were estimated on four dates in 2019. To aid in validation, estimates were compared with that of the Bayesian linear mixing model framework, MixSIAR. The two approaches provided similar results, but due to its continuous and parametric nature, PRIME provided estimates of superior resolution, certainty, and model parsimony. Although both models incorporate additional physical information into their mixing frameworks , PRIME does so in a mechanistic manner, thereby reflecting the relevant hydrological processes more effectively than the purely empirical approach taken by MixSIAR. Furthermore, because PRIME uses a continuous function to describe the predicted uptake pattern, it allows users to quantify water uptake with essentially infinite resolution, through integration over the desired depth ranges. These findings demonstrate the advantages of utilizing a continuous, parametric, and process-based mixing model to estimate root water uptake apportionment, thus providing a relatively simple yet powerful tool with which to approach plant water sourcing. 
Arsenate aqueous solution – anglesite PbSO4 interface: dissolution, precipitation, and arsenic sequestration
Authors: Stępień Ewa , Manecki Maciej
Published: March 2024

The circulation of toxic elements through soils, sediments and aquatic environments remains a significant environmental problem, which implies several, often unrecognized health risks. Dissolution and precipitation reactions that result in formation of sparingly soluble crystalline compounds containing toxic elements e.g. As, appear to be a promising strategy for reducing their chemical mobility and bioavailability (Magalhães, 2002; Wang et. al., 2013).In this study, the processes occurring at the interface of anglesite and solutions containing AsO43- ions were investigated. The results provide insight into the mechanism of As immobilization on the mineral surface through transformation of labile form into less reactive and more thermodynamically stable phases. Synthetic anglesite powder and fragments of natural anglesite crystals (Tsumeb, Namibia) were reacted for up to 3 months with solutions containing AsO43- (50 mg As/l) in the presence of Cl- ions at pH range 2 - 8. The experiments were conducted at room temperature (20 oC) or in the autoclave (120 oC).Rapid sequestration of As from the solution was associated with precipitation of mimetite Pb5(AsO4)3Cl: over 66% of As was removed within 24 hours. After 7 days of the reaction, the concentration of As decreased from 50 to less than 11 mg As/L. The concentration of Pb2+ ranged from 0.6 mg Pb/L at pH 8 to 20 mg Pb/L at pH 2. Both, homogeneous and heterogeneous precipitation of mimetite was observed, and some anglesite crystals were covered by incrustations. At pH=2, mimetite was associated with schultenite PbHAsO4.Scanning Electron Microscopy observations of the natural crystals surface, indicated that the reaction of As-containing solutions with anglesite at pH 4-8, involves dissolution of PbSO4, resulting in formation of etch pits, followed by precipitation of randomly intergrown mimetite as a loosely bound crust. The crust was formed in the vicinity but is separated from anglesite surface. In contrary, at very acidic conditions (pH=2), anglesite is replaced by a secondary phase as a result of a coupled dissolution and precipitation, leading to formation of lead arsenate pseudomorph. Surprisingly, temperature had no significant effect on the reaction, while the pH control is of great importance and determines the mechanism.References:Magalhães, M. C. F. (2002). Arsenic. An environmental problem limited by solubility. Pure and Applied Chemistry, 74(10), 1843–1850.Wang, L., Putnis, C. V., Ruiz-Agudo, E., King, H. E., & Putnis, A. (2013). Coupled dissolution and precipitation at the cerussite-phosphate solution interface: Implications for immobilization of lead in soils. Environmental science & technology, 47(23), 13502-13510.This research was funded by AGH University of Kraków project No 16.16.140.315.  
Why earthquakes cause disasters and how to counteract it?
Authors: Ismail-Zadeh Alik
Published: March 2024

Scientific discoveries on earthquake occurrences integrated into hazard, vulnerability and exposure studies help in disaster risk assessment and its understanding. Research on the lithosphere dynamics, extreme seismic occurrences, and earthquake forecasting as well as seismic hazards assessments and early warning have significantly advanced during the last decades. Numerical earthquake simulations coupled with a seismic hazard analysis provide a better assessment of potential ground shaking due to future large earthquakes. Hazard analysis, modeling, and forecasting help in development of preventive measures aimed to reduce impacts of extreme events. Meanwhile, we cannot counteract disasters without the nexus between the scientific knowledge on seismic hazards, preparedness to large earthquakes and public awareness about disaster risks. Integrating natural, engineering, social and behavioral sciences and practices with policymaking should significantly improve measures to reduce disaster risks. To this end, a fundamental change in scientific approaches to disaster risk reduction is needed by shifting the current emphasis on individual hazard assessment (e.g., seismic hazard assessment only), which is dominant in the geoscientific community, to a transdisciplinary system analysis with action-oriented research on disaster risk co-produced with multiple stakeholders. This will allow for acquisition of policy-relevant knowledge and its immediate application to evidence-based policy and decisionmaking for risk reduction.
Overview of the EZIE (Electrojet Zeeman Imaging Explorer) Mission
Authors: Yee Jeng-Hwa , Gjerloev Jesper , Mosavi-Hoyer Nelofar , Wind-Kelly Rebecca , Swartz William , Misra Sidharth
Published: March 2024

EZIE, the Electrojet Zeeman Imaging Explorer, is a NASA three-Cubesat Heliophysics mission scheduled to launch in late 2024 or early 2025. It employs four downward and cross-track looking miniaturized radiometers on each of the 6U CubeSat, flying in a pearls-on-a-string managed formation, to measure, for the first time, the two-dimensional structure and the temporal evolution of the electrojets flowing at altitudes of ~100–130 km. The four identical radiometers simultaneously measure polarimetric radiances of the molecular oxygen thermal emission at 118 GHz and employs the Zeeman sensing technique to obtain the current-induced magnetic field vectors at ~80 km, an altitude region very close to the electrojet.  This measurement technique allows for the remote sensing of the meso-scale structure of the electrojets at four different cross-track locations simultaneously at altitudes notoriously difficult to measure in situ. The compact 118-GHz heterodyne spectropolarimeters leverage technologies demonstrated by NASA’s TEMPEST-D and CubeRRT missions and the CubeSat bus from RAVAN, CAT, TEMPEST-D, and CubeRRT. Differential drag maneuvers are used to manage satellite along-track temporal separation to within 2–10 minutes between adjacent satellite to record the electrojet temporal evolution without the need for on-board propulsion. The combination of the sensing technique, compact instrument and Cubesat technologies allow EZIE to cost-effectively obtain never-before “mesoscale” measurements needed to understand how the solar wind energies stored in the magnetosphere are transferred to the thermosphere and ionosphere.  In this paper, we will present an overview of the EZIE mission, its science objectives, the Zeeman sensing technique employed, and the measurement products to be provided.
Production of standard gases for routine calibration of stable isotope ratios of N2 and N2O 
Authors: Well Reinhard , Buchen-Tschiskale Caroline , Burbank Joachim , Dannenmann Michael , Lewicka-Szczebak Dominika , Mohn Joachim , Rohe Lena , Scheer Clemens , Tuzzeo Salvatore , Wolf Benjamin
Published: March 2024

There is need to calibrate raw data of N2 and N2O isotopocules due to effects of non-linearity, instability, matrix effects and interference with trace gases. Our objective was thus to supply a variety of suitable standard gases for members of the DASIM research unit (www.DASIM.de) and their partners in sufficient amount for routine use to enable calibration for extended time. In total 23 different mixtures were produced to cover all isotopic approaches to study N2 and N2O production and cycling in soils with stable isotopes and suitable for IRMS and laser spectroscopy.Standards for the 15N gas flux method should mimic mixtures of N2 and N2O emitted from highly 15N enriched nitrate in soil and atmospheric background. These must thus contain unlabelled, single-labelled  as well as double-labelled N2 and N2O.N2O standards for natural abundance must cover a range of N2O concentrations and isotopocule values typically found in field flux and laboratory incubation studies to correct for non-linearity and bias.Premixtures were prepared by mixing isotopically enriched or depleted gases which were either commercially available or produced in the lab. Moreover, pure N2O of natural abundance was supplied from a previous project (Mohn et al., 2022, https://doi.org/10.1002/rcm.9296). Premixtures were diluted in artificial atmospheres and compressed in commercial tanks.We will explain the production of mixtures, give an overview of the manufactured mixtures and show first results of analysis in comparison with ideal values.
Can a wrf hybrid 4DEnVar iso system be used to improve forecasts for convective scale systems? A roadmap to using isotope enabled assimilation systems for studying convective scale systems. 
Authors: Steinwagner Jörg , Tjemkes Stephen
Published: March 2024

The assimilation of L2 satellite data is much less CPU intensive than the assimilation of L1 radiation data. However, L2 data usually carries background information that produces artifacts in assimilation results. Migliorini et al. proposed a method to extract the background information from L2 data, transforming the remaining L2 data to ‘feature space’. We successfully applied Migliorini transformed L2 data in an ensemble-based assimilation scheme for a wrf hybrid-4DEnVar system.
Recent developments in the assimilation of water isotope information indicate that this additional isotopic information, most likely due to the more precise characterization of the moisture cycle, can improve forecast skills of NWP models. So far, there has been no direct assimilation of space-based L2 isotope information in models. With the Migliorini transformation isotopic L2 measurements could be introduced to assimilation systems. With a better understanding of moisture cycles and better forecast skills it is likely that pre-convective situations, e.g. in the starting phase of regional scaled storm events, can be characterized more accurate. Together with reduced CPU needs for the L2 assimilation it becomes now feasible to carry out small scale studies, even on convective scale, for small or medium sized institutions. And a larger pool of users most likely will propel our understanding of convective scale processes.         
Integrated water balance reveals that Lake Titicaca is driven by extreme climate variability
Authors: Lima Nilo , Ruelland Denis , Escobar Marisa , Rabatel Antoine , Lavado Waldo , Condom Thomas
Published: March 2024

For decision making, it is crucial to provide an estimate of the main water balance fluxes to help understand trends and drivers of lake fluctuation in the past and in the future. However, the quantification of fluxes is a complicated task due to the scarcity of hydro-climatic data in space and over time, which hampers addressing all the local and regional hydrological processes at play, notably in the face of multi-decadal climatic and anthropogenic changes. These challenges are addressed at the scale of the Lake Titicaca hydro-system (57000 km2). Lake Titicaca (8400 km2) is located at 3812 m a.s.l. in the Altiplano of South America. Lake water levels measured since the beginning of the last century show extreme fluctuations within a range of approximately 6 m. This study presents an approach to disentangle the climatic and anthropogenic drivers of past  fluctuation of Lake Titicaca. For this, we implemented a conceptual integrated modeling chain that represents the following components: (i) production and routing processes based on a precipitation-runoff model including snow and glacier as well as net water consumption from irrigation in order to estimate lake inflows; and (ii) lake basic functioning according to inflows, direct precipitation and evaporation, bathymetry and outflows. The modeling chain was implemented in the Water Evaluation and Planning System (WEAP) platform at a daily time step over a 30-year period (1985–2015) and was driven by climate inputs derived from ground station data and ERA5 reanalysis. Model calibration and evaluation was based on geodetic mass balance, catchment streamflow, and lake water levels. The results indicate that the estimated annual water balance in the upstream catchments shows that the climate regime is mainly dominated by rainfall since snowfall only represents 1% of total precipitation (716 mm). Ice melt also accounts for 1% of total precipitation. The simulated actual evapotranspiration represents on average 565 mm year-1, of which 3% correspond to net irrigation consumption. Runoff is approximately 173 mm year-1. By scaling this runoff to the lake area, upstream inflow represents 53% of the total inflows into the lake (1818 mm year-1), the remaining 47% corresponding to direct precipitation over the lake. Evaporation losses from the lake are estimated to mean annual value of 1718 mm and downstream outflows 142 mm. Then, the Lake Titicaca is primarily driven by interannual variations in precipitation. The evaporation rate can exacerbate conditions in dry years. The integrated modeling chain will later be used to assess how water levels could be altered by climate change and management options such as water withdrawals and lake releases.
Revisiting the Johnson-Koplik-Schwartz characteristic length to relate transport properties in partially saturated porous media, insights from a fractal-based petrophysical approach
Authors: Jougnot Damien , Thanh Long Duy , Solazzi Santiago , Luo Haoliang
Published: March 2024

In petrophysics, characteristic lengths are used to relate fundamental transport properties of porous media. However, these characteristic lengths have mostly been defined and tested in fully saturated conditions, with few exceptions. This contribution revisits the seminal work of Johnson-Koplik-Schwartz (JKS) length, which represents an effective pore size controlling various transport-related properties of porous media, such as permeability and electrical conductivity. A novel closed-form equation is presented to predict the behavior of this characteristic length in partially saturated media for different saturation states. Using previous models in the literature that predict the intrinsic and relative electrical conductivities under partially saturated conditions, we infer the JKS length as functions of water saturation and properties associated with the pore-size distribution of the considered porous medium. The proposed method allows for the direct estimation of effective and relative permeability through electrical conductivity measurements. This creates new opportunities for remotely characterizing partially saturated media. We believe that this new model has potential for various applications in reservoir (CO2 or hydrogen storage) and vadose zone studies.
Measuring and modelling seismic surface-wave dispersion variations in various hydrogeological contexts
Authors: Bodet Ludovic , Sanchez Gonzalez Ramon , Cunha Teixeira José , Dangeard Marine , Gesret Alexandrine , Rivière Agnès
Published: March 2024

Pressure (P) or shear (S)-wave velocity models of the near-surface can be simultaneously estimated along coincident arrays from P-wave refraction tomography and surface-wave (SW) dispersion inversion methods. Over the past decade, this approach has been integrated into the hydrogeophysics toolbox to image spatial variations of VP/VS (or Poisson) ratio, as its evolution is strongly associated with water content (or saturation) contrasts. The relevance of this method has been verified in various Critical Zone (CZ) observatories, each with distinct hydrogeological characteristics such as continuous multi-layered hydrosystems or fractured environments with strong discontinuities. It has also proven successful in other contexts and application scales, including a hydrothermal site or partially saturated glass beads in a laboratory experiment. However, we identified two major issues: (1) the combined use of P-wave traveltime tomography and SW dispersion inversion involves distinct characteristics of the wavefield and different assumptions about the medium, providing VP and VS models with different sensitivity, resolution, investigation depth, and posterior uncertainties; (2) the involved inversion processes use a small number of layers that cannot properly describe the continuous variations of subsurface hydrological properties. In particular, we noted that VP/VS (or Poisson) ratio was only consistent with strong saturation contrasts and often faced difficulties in retrieving water content variations in the unsaturated zone. This underscores the need to use petrophysical approaches to build alternative forward models and improve inversion processes. Adapted rock physics models have thus recently been developed to take capillary suction effects into account in the effective stress of the soil. In this study, we first present several datasets obtained from various contexts in which SW dispersion variations have been observed and related to changes in water content and/or water table depths. We then suggest using the previously cited rock physics models to simulate these data and show how it helps in understanding the involved hydrofacieses and processes. We finally address the relevance of surface-wave dispersion inversion approaches involving such forward models and discuss the possible use of additional attributes of the seismic wavefield to constrain interpretations.
The impact of flood events on the spatio-temporal variability of microplastics in the river sediments of two contrasting streams discharging towards the southern Caspian Sea
Authors: Dehbandi Reza , Rasouli Zainab , Zazouli Mohammad Ali , Khodabakhshloo Nafiseh , Mousavinasab Nouraddin , Nejati Habib , Esfandiari Yahya , Singh Jaswant , Krause Stefan
Published: March 2024

Microplastics (MPs), as global emerging pollutants, have received significant attention worldwide due to their wide spread presence in aquatic and terrestrial ecosystems. However, the mechanisms controlling their fate and transport through river networks remains poorly understood. This study investigates the spatio-temporal distribution of MPs in two contrasting rivers (Tajan and Talar) discharging to southern coasts of the Caspian Sea, Iran and identifies pollution sources and their activation. In both rivers, MPs were dominated by black-gray larger-sized (1000-5000 μm) Polystyrene (PS)particles. Spatially, MPs concentrations in both rivers differ from upstream to downstream and showed uneven distribution. The March 2019 flood event affected on the concentration and patterns of MPs in river sediments. The total MPs concentration in both river sediments in all stations significantly decreased from pre to post-flood time (p-value
Neogene biostratigraphy in the  Niger Delta by  intergrating  foraminifera and  Paleo-oceonographic implications
Authors: Solomon Joshua Avong , Obiosio Enam , Ibrahim Hamidu , Gospower Ubit , Anyanna Linus
Published: March 2024

The Cenozoic Niger Delta formed after the separation of the African and South American plates.An integrated micropaleontology analysis was employed based on foraminifera studies  to determine age, biostratigraphic zonation, paleowaterdepth, paleosalinity and sea-level history of the well interval based on ditch cutting samples. Foraminifera preparation was based on standard micropaleontology preparation techniques and identification, which showed a high diversity and abundance of both planktonic and benthonic foraminifera occurrence. The planktonic foraminifera: Globigerinoides bulloidues, Globigerinoides primordius, Globorotalia obesa, Globigerinoides sp.,Catapsydrax stainforthi showed the entire deposition took place during the early to late Miocene (N6-N17) based on the First Downhole Occurrence (FDO) and Last Downhole Occurrence (LDO).The boundary resolution between the Early and Middle Miocene was identified based on the FDO of Catapsydrax stainforthi and the boundary between Middle and Late Miocene based on the FDO Globorotalia obesa. Two benthic biozones are proposed for the well interval equivalent to the N11-N17 and N6-N11 based on bioevents of chronostratigrahically significant benthonic foraminifera and whose stratigraphic range were well established in the Niger Delta and worldwide. Three third-order sea-level rises and falls occurred during the Early to Late Miocene within the Niger Delta, with a corresponding paleo-waterdepth from transitional to outer neritic based on biofacies such as ; Ammonia beccarii, Quinqueloculina microcostata, Poritextularia panamensis, Uvigerina subperegrina, Brizalina mandoroveensis, Lenticulina grandis and Eponides eshira.The maximum flooding surfaces shown by,the Chiloguembelina-3 Shale (16.0 Ma), Dodo Shale (11.6 Ma) and the Uvigerina-8 Shale (9.2 Ma), were associated with transgression. The 15.5 Ma SB of Depositional Sequence 1(Early Miocene), 10.5 Ma SB of Depositional Sequence 2(Middle Miocene) and 8.5 Ma SB of Depositional Sequence 3(Late Miocene) due to progradation, resulting in three depositional sequences established within the study interval. This showed  that the study interval was exposed to three local depositional cycles (cycle 6,9and 10), three regional cycles (cycles 2.3,2.6 and 3.1) within the TB2  and TB3 super cycles, correlated to the Niger Delta chronostratigraphic sea-level chart, which indicated that the sedimentary cyclic pattern was due to tectonics, eustatic and climatic conditions. Based on the triangular plot of the foraminifera test type (arenaceous, porcelaneous and hyaline), suggests a transition from the brackish marginal marine environment to open neritic conditions. The study interval is said to have penetrated sediments of the parallic Early to Late Miocene Agbada formation. Keywords: Biostratigraphy, Early-Late Miocene, Planktonic Foraminifera, Benthic Foraminifera, sedimentary cyclic pattern
Exploring ice cloud formation mechanisms through satellite observations and integrated Lagrangian transport with microphysical models
Authors: Saiprakash Athulya , Krämer Martina , Konjari Patrick , Rolf Christian , Riedi Jérôme , Sourdeval Odran
Published: March 2024

Understanding the formation mechanisms of ice clouds has been hindered by the complexity of their composition and the diversity of their growth processes. Previously, observational constraints have been limited, leading to substantial gaps in our comprehension and representation of ice clouds. Satellite measurements face a significant challenge due to the lack of essential environmental context information, that is necessary to identify and understand the cloud's formation mechanism and evolution. Indeed, these representations only capture a snapshot of the state of a cloud and its microphysical properties at a given time. This study addresses this limitation by providing additional metrics on ice cloud history and origin along with operational satellite products.Here, we present a novel framework that combines satellite observations with Lagrangian transport and ice microphysical models, to obtain information on the history and origin of air parcels that contributed to their formation. The air mass transport model CLaMS (Chemical LAgrangian Model of the Stratosphere) was employed to track the trajectory of air parcels along the DARDAR-Nice track. CLaMS-Ice model is jointly used to simulate cirrus clouds along trajectories derived by CLaMS. This approach provides information on the cloud regime as well as the ice formation (in-situ vs liquid origin) pathway. Our findings, derived from case studies involving multiple cloud types, present a realistic representation of these complex processes. We explore the sensitivity of our methodology to initial conditions and thresholds. Additionally, a statistical analysis examines how satellite cloud microphysics are sensitive to CLaMS-Ice metrics. This comprehensive approach advances our understanding of ice cloud processes and helps to refine satellite-based representations of these atmospheric phenomena. 
The influence of anthropogenic greenhouse gases emissions on noctilucent clouds and their response to the solar cycle
Authors: Vellalassery Ashique , Baumgarten Gerd , Grygalashvyly Mykhaylo , Lübken Franz-Josef
Published: March 2024

The increasing emissions of greenhouse gases, especially CO2  and CH4, have a significant impact on Earth’s climate as they contribute to global warming. In the upper atmosphere, however, the consequences are different. Understanding the impact of this phenomenon on the upper mesosphere is challenged by difficulties and limitations in measuring atmospheric properties. Noctilucent clouds (NLCs) have been proposed as important tracers in the summer mesopause region due to their high sensitivity to atmospheric background conditions such as temperature, water vapor concentration, and dynamics. Recently, we studied the long-term trends in the response of NLC properties and the background atmosphere to the solar cycle during the period 1849-2019, which covers 15 complete solar cycles (Solar Cycle 10 to Solar Cycle 24) with increasing concentrations of CO2 and CH4. We utilized model simulations from the Leibniz Institute Middle Atmosphere (LIMA) and the Mesospheric Ice Microphysics And tranSport (MIMAS) over 170 years. We found that background temperature and H2O show an apparent response to the solar cycle throughout the study period, which intensified after 1960 due to increased greenhouse gas emissions. The properties of NLCs, such as maximum brightness, mean radius of ice particles, and ice water content (IWC), respond to the solar cycle, and these responses increase with time mainly due to an increase in water vapor. NLC altitude responds positively to the solar cycle, mainly due to temperature changes caused by the solar cycle. The response of NLC properties to the solar cycle varies with latitude, with most NLC properties showing larger and similar responses at higher latitudes (69°N and 78°N) than at mid-latitudes (58°N). We will also present results from our recent simulations projecting into the future up to 2070, based on RCP 8.5 scenarios for increasing greenhouse gases.
Unleashing the archive of aerial photographs of Iceland, 1945-2000. Applications in geosciences 
Authors: Belart Joaquín M. C. , Gunnarson Sydney , Berthier Etienne , Dehecq Amaury , Jóhannesson Tómas , Hannesdóttir Hrafnhildur , Baxter Kieran
Published: March 2024

The archive of historical aerial photographs of Iceland consists of ~140,000 vertical aerial photographs acquired between the years 1945 and 2000. It contains an invaluable amount of information about human and natural changes in the landscape of Iceland. We have developed a series of automated processing workflows for producing accurate orthomosaics and Digital Elevation Models (DEMs) from these aerial photographs, which we’re making openly available in a data repository and a web map visualization service. The workflow requires two primary inputs: a modern orthomosaic to automatically extract Ground Control Points (GCPs) and an accurate DEM for a fine-scale (sub-meter) alignment of the historical datasets. We evaluated the accuracy of the DEMs by comparing them in unchanged terrain against accurate recent lidar and Pléiades-based DEMs, and we evaluated the accuracy of the orthomosaics by comparing them against Pléiades-based orthomosaics. The data are becoming available at https://loftmyndasja.lmi.is/. To show the potential applications of this repository, we present the following showcases where these data reveal significant changes the landscape in Iceland in the past 80 years: (1) volcanic eruptions (Askja 1961, Heimaey 1973 and the Krafla eruptions, 1975-1984), (2) decadal changes of Múlajökull glacier from 1960-2023, (3) Landslides (Steinsholtsjökull 1967, Tungnakvíslarjökull 1945-present) and (4) coastal erosion (Surtsey island).