bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling the Impacts of Deforestation: local drying of the atmosphere and potential effect on downwind precipitation.
Authors: Devenet Clément , de Noblet Nathalie , Ottlé Catherine , Viovy Nicolas , Chéruy Frédérique
Published: February 2023

The Amazon rainforest is a vital component of the hydrological cycle of South America. Its evapotranspiration is an essential supply of atmospheric moisture for precipitation in more southern regions of the continent. The potential impacts of deforestation on precipitation in these distant regions are yet not fully understood.The present research project aims at quantifying the deficit of evapotranspiration occurring at the location of deforestation, focusing on the southern part of Amazonia, which has experienced intense deforestation since the 80s. We first use the ORCHIDEE land surface model forced with the reanalysis dataset CRU-JRA to simulate the impacts of an imposed land cover change: from observed states of vegetation cover to a massive extension of croplands. The ORCHIDEE model computes all the components of evapotranspiration, giving, in turn, the expected deficit of atmospheric moisture at the location of the land cover change.Then, thanks to existing datasets connecting any place on Earth with the area that supplies its moisture through the atmosphere, we link this deficit with downwind locations highly dependent on this upwind evapotranspiration for its precipitation. From there, we draw hypotheses about the potential changes in precipitation amounts and seasonality.In the project’s second phase, these hypotheses are tested against land-atmosphere coupled simulations produced with the IPSL global climate model, nudged to winds from the ERA5 reanalysis. The model grid is zoomed on the South American continent to better describe the atmospheric transport in the region. The land-atmosphere coupled simulations provide information on the atmospheric feedback induced by the land cover change, confirming or invalidating the hypotheses. Since land cover affects not only water fluxes but also energy fluxes, the coupled model experiments give us insights into the atmospheric processes at stake, the changes in cloudiness and local convection, and the potential shifts in precipitation location or timing.
Managing complex social-hydrological systems for water security: the case of the mountain cryosphere
Authors: Drenkhan Fabian , Buytaert Wouter , Mackay Jonathan D. , Barrand Nicholas E. , Hannah David M. , Huggel Christian
Published: February 2023

In many mountain regions, the cryosphere is a crucial component of water provision to downstream societies, as it contributes to dry-season flows and sustains diverse ecosystems. However, many of the world’s glacierized watersheds experience far-reaching changes at accelerated pace due to declining glaciers and snowpack, climate change impacts and socioeconomic development in the non-cryospheric parts of the catchment. The implications for downstream water supply are therefore manifold and complex. Coupled effects of reduced and less reliable water availability, changes in water quality, and growing water demand exert increasing pressure on water resources and threaten future water security and management.We argue that the limited understanding of interactions between the cryosphere, glacial and non-glacial water stores, river runoff and people hamper climate change adaptation and long-term water security. Meaningful assessments of mountain water security require therefore a holistic social-ecological perspective that interlinks the wider catchment hydrology considering both, surface and subsurface stores, and people including human water demand with improved data and process understanding. Water security assessments can then be guided by a fully coupled hydrological risk framework. This approach needs to integrate multiple social-ecological vulnerabilities as well as the degree of exposure to water shortage under a variety of possible future scenarios of glacier shrinkage, catchment alteration and socioeconomic development. Essentially, this requires a thorough understanding of interrelated upstream-downstream systems and the spatiotemporal propagation of meltwater through the terrestrial water cycle.Improved data and more diverse knowledge collection that point to the missing links in the terrestrial water cycle are a priority. Multiple sources of knowledge should be co-produced and integrated into a collaborative science-policy-community framework, ideally from the early stages of research planning with attention to local practices and governance. This approach can support a wide set of incremental and transformational strategies that guide robust, locally tailored and effective adaptation pathways. These may include, among other, exploring catchment-specific benefits of nature-based solutions to increase the buffer function of wider catchment hydrology against water loss from glacier shrinkage to enhance long-term water security.
On the use of MARRMoT for rainfall-runoff modelling in Irish raised bogs
Authors: Mozafari Behzad , O'Loughlin Fiachra , Bruen Michael , Donohue Shane , Regan Shane , Renou-Wilson Florence
Published: February 2023

Peatlands cover over 20% of Ireland’s landscape, but most have been disturbed by human activities, including land use changes, which alter their natural hydrological functions. As a result, there is a growing need for restoration measures, which require reliable predictive modelling tools for assessing their feasibility and effectiveness. However, choosing a suitable hydrological model, particularly at the catchment scale, can prove challenging. While simplified conceptual rainfall-runoff models remain indispensable water management tools due to their fewer parameters, less input data, and low computational requirements, a critical issue is the limited number of conceptual models that have been successfully applied to peatlands. This is reflected in the lack of intercomparison studies that explore the performance of different model structures for different peatland types. Here, we report on the use of the Modular Assessment of Rainfall-Runoff Models Toolbox (MARRMoT) to analyze the performance of various model structures for three drained, restored, and natural Irish raised bogs. The framework provides a flexible platform for emulating (to a reasonable extent) and comparing different conceptual models within its structure. We emulated the Wageningen Lowland Runoff Simulator (WALRUS) model, which is designed specifically for lowland catchments, and compared it with the other 47 existing models within the framework. The performance of each model was assessed using four goodness-of-fit (GOF) measures. The results revealed a wide range of applicability, which led to several models being excluded from consideration. While the warm-up and calibration periods were limited to less than one year, the reported GOFs provide an invaluable insight into the dynamic performance of the models and the choice of model structure for simulating surface runoff in Irish raised bogs.
Ship emissions and apparent sulphur fuel content measured of board of a large research aircraft in international waters and Sulphur Emission Control Area
Authors: Pasternak Dominika , Lee James , Nelson Beth , Alexiadou Magdalini , Temple Loren , Bauguitte Stéphane , Batten Steph , Hopkins James , Andrews Stephen , Mathews Emily , Bannan Thomas , Wu Huihui , Thamban Navaneeth , Marsden Nicholas , Yang Ming-Xi , Bell Thomas , Coe Hugh , Bower Keith
Published: February 2023

Since 1st January 2020 the legal sulphur content of shipping fuel was decreased – from 3.5% to 0.5% by mass outside of the Sulphur Emission Control Areas (SECAs) to improve coastal air quality. A possible downside of this change was acceleration of climate change since sulphur is believed to be a negative climate forcer and sipping is one of its main sources. Further question was the level of compliance to the new rules, especially in the open waters. Another climate related aspect of shipping is recent growth in the liquified natural gas (LNG) tanker fleets. LNG is considered the greenest of the fossil fuels, however there are few empirical studies of methane emissions from marine LNG transport.The Atmospheric Composition and Radiative forcing changes due to UN International Ship Emissions regulations (ACRUISE) project aims to address the above considerations. During three field campaigns the FAAM Airborne Laboratories’ large research aircraft was deployed to target ships in coastal shipping lanes and open waters. First measurements were performed in July 2019 (before regulation change) in shipping lanes along the Portuguese coast, the English Channel SECA and the Celtic Sea. Further two campaigns were delayed by the COVID-19 pandemic until September 2021 and April 2022, targeting ships in the Bay of Biscay, the English Channel SECA and the Celtic Sea. Throughout the project, nearly 300 ships were measured during 30 research flights, varying from plume aging and cloud interaction studies, through collecting bulk statistics in busy shipping lanes to comparing emissions in and out of SECA. This work focuses on the gaseous species measurements (SO2, CO2, CH4 and VOCs from whole air samples). They are used to study changes in apparent sulphur fuel content of the ships observed throughout ACRUISE, plume composition and methane emissions from LNG tankers.
Probabilistic modelling of water quality in the Ramganga River, India, informed by sparce observational data
Authors: Glendell Miriam , Sinha Rajiv , Choudhary Bharat , Singh Manudeo , Ray Surajit
Published: February 2023

Impaired water quality continues to be a serious problem in surface waters worldwide. Despite extensive regulatory water quality monitoring implemented by the Government of India over the past two decades, the spatial and temporal resolution of water quality observations, the range of monitored contaminants and data related to characterisation of point source effluents are still limited. In addition, discharge data for trans-boundary rivers is considered sensitive information and is not publicly available. Hence, quantifying, and mitigating pollutant loads and planning effective mitigation strategies are hindered by data paucity and there is an urgent need for the development of decision support tools (DST) that can account for these uncertainties.In this study, we tested the application of a probabilistic DST based on Bayesian Belief Networks, to evaluate pollution risk from nutrients (phosphate, nitrate, ammonia), sediments and heavy metals (Cd, Cr, Cu, Pb, Zn) in the Ramganga river basin (30,839 km2), the first major tributary of the Ganga in the state of Uttar Pradesh, India, and is understood to be a significant source of pollution into the Ganga River, contributed from a range of industries, domestic sources and intensive farming practices. Bayesian belief networks are graphical causal models that enable to integrate observational data (both spatial and temporal) with data from literature and expert knowledge within a probabilistic framework, whilst accounting for uncertainty.The objectives of this study were to 1) develop a parsimonious conceptual model of the system that allows harnessing diverse but limited data, 2) evaluate the important components of the system to inform further data collection and management strategies, and 3) simulate plausible management scenarios. We simulated the impacts of point source management interventions on pollution risk, including provision of sufficient municipal sewage treatment plant (STP) capacity, enhanced STP treatment levels and sufficient industrial wastewater effluent treatment capacity. We found a clear effect of enhanced STP interventions on improved regulatory standard compliance for nitrate (from 92% to 95%) and phosphate (from 33% to 41%). However, the effect of interventions on heavy metal pollution risk was not clear, due to considerable uncertainties related to the lack of reliable discharge data and the characterisation of industrial effluent quality. The parsimonious DST helped to collate the available understanding related to water quality impacts from multiple pollutants in the Ramganga river basin, while sensitivity analysis highlighted critical areas for further data collection.
An interpretable neural network approach to identifying sources of predictability in the future climate
Authors: Gordon Emily , Barnes Elizabeth
Published: February 2023

Earth system predictability on decadal timescales can arise from both low frequency internal variability as well as from anthropogenically forced long-term changes. However, on these timescales, the chaotic nature of the climate system makes skillful predictions difficult to achieve even if we include information from climate change projections. Furthermore, it is difficult to separate the contributions from internal variability and external forcing to predictability. One way to improve skill is through identifying and harnessing initial conditions with more predictable evolution, so-called state-dependent predictability. We explore a neural network approach to identify these opportunistic initial states in the CESM2 large ensemble and subsequently explore how predictability may manifest in a future climate, influenced by both forced warming and internal variability. We use an interpretable neural network to demonstrate that internal variability will continue to play an important role in future climate predictions, especially for states of increased predictability.
Development and deployment of a “Mid Cost” sensor network for urban Greenhouse Gases and Air Quality monitoring with a focus on CO2.
Authors: Chariot Mali , Laurent Olivier , Delanoe Damien , Nief Guillaume , Utard Hervé , Lienhardt Luc
Published: February 2023

As part of the European research project ICOS-Cities, the Laboratoire des Sciences du Climat et de l'Environnement (LSCE) and Origins.earth are seeking to extend the Greenhouse Gases (GHG) measurement network in Paris and its immediate suburbs by installing new sensors on the roofs of tall buildings. Each sensor will measure CO2 concentration in real time, which will then be used in an inversion model to determine CO2 emissions at the scale of a district. Several sensors will be upgraded in a second phase with the addition of an Air Quality (AQ) measurement cell.We present a new stand-alone sensor box design (called AtmoBox) that allows to connect GHG and AQ sensors in a single box, as well as the implementation of these Atmoboxes in a ground-based atmospheric monitoring network. In addition to 9 long-term stations equipped with high precision CRDS spectrometers, about 30 Mid Cost instruments are deployed within Paris and its near suburb, measuring CO2 through NDIR sensors. We will detail the steps from the search for suitable sites for the urban measurements, the characterisation of the sensors in relation to the environmental parameters in the laboratory, the related calibration and quality control strategy to meet the performance objective and the performance assessment of the sensors.
Implementing FAIR metrics and assessments for the Earth and Environmental Sciences
Authors: Huber Robert , Pierkot Christelle , Vernet Marine , Strollo Angelo
Published: February 2023

Although there has been great acceptance across disciplines for years to make research data FAIR (findable, accessible, interoperable, and reusable), there is still no consensus in most communities on how to implement this concretely on a discipline-specific basis. Available metrics are exclusively domain agnostic, and there are few approaches to formulate binding metrics and tests specifically for particular domains  (e.g. earth and environmental science disciplines) and to implement them in assessment tools.In this presentation, we will introduce new approaches being developed in the FAIR-IMPACT project, based on domain specific use case partners and their communities, including those from the earth and environmental sciences (e.g. collaboration with the communities involved in the FAIR-EASE project), to extend and thus adapt existing FAIR metrics for assessing data objects and the F-UJI FAIR Assessment Tool to more fully incorporate the disciplinary, 'geo' context. A particular focus here will be on incorporating geo-specific metadata standards, covering data formats and semantic artefacts  within FAIR metrics, and the detection or verification of these standards by the F-UJI FAIR Assessment Tool.

We will finally report also on the collaboration with one of the EIDA Data Centers (as part of the European Infrastructure for seismic waveform data in EPOS) where the F-UJI FAIR Assessment Tool has been further developed to be aware of the very domain specific standard data and metadata as well as services. 
Sensitivity of Sentinel-1 observations to snow properties, comparing radar backscatter, polarimetric decomposition parameters, and interferometric phase changes
Authors: De Breuck Morgane , Lievens Hans , Jans Jonas-Frederik , Beernaert Ezra , Verhoest Niko
Published: February 2023

Remote sensing can offer important information on snow properties at the global scale. However, the sensitivity of satellite radar measurements at C-band (5.4 GHz) from the ESA and Copernicus Sentinel-1 (S1) mission to snow properties still requires further investigation. This study provides the first results of a detailed sensitivity analysis, carried out over the European Alps at 1-km spatial resolution. It includes three processing types of radar measurements: radar backscatter observations in vertical-vertical (VV) and vertical-horizontal (VH) polarizations, polarimetric decomposition parameters (e.g., H-Alpha dual polarization decomposition), and interferometric phase change and coherence between successive S1 acquisitions from the same relative orbit. The sensitivity of the different radar measurements is investigated with respect to snow properties (snow depth, snow water equivalent, wet-dry snow state), soil properties (surface soil moisture, soil temperature), and vegetation properties (LAI), and furthermore stratified by snow climatology, land cover, and elevation. Preliminary results suggest that, in regions with significant snowfall and limited vegetation, the VH backscatter correlates strongest with snow depth and SWE, whereas the VV backscatter is more strongly correlated with soil properties. The Alpha polarimetric decomposition parameter increases with snow accumulation, indicating increased contributions of volume scattering and multiple scattering. The often low interferometric coherence is confounding the interpretation of interferometric phase changes in mountainous regions. In conclusion, the first results of this sensitivity study indicate the usefulness of S1 radar backscatter and polarimetric decomposition parameters for snow retrieval algorithm development.
A long way of water vapor from the Asian Summer Monsoon into the stratosphere
Authors: Konopka Paul , Rolf Christian , von Hobe Marc , Khaykin Sergey M. , Clouser Benjamin , Moyer Elizabeth , Ravegnani Fabrizio , Viciani Silvia , Afchine Armin , Krämer Martina , Stroh Fred , Ploeger Felix
Published: February 2023

During the StraoClim Geophysica campaign, moist air with total water mixing ratios up to 200 ppmv was observed within the Asian Summer Monsoon anticyclone, above the local cold point tropopause (CPT). High ozone mixing ratios of up to 250 ppbv suggest substantial stratospheric moistening. We used 60-day back- and forward trajectories to classify the observations into two groups based on their distance to the Lagrangian dry point (LDP): those where the LDP has just occurred or is still expected to occur (type A, 0-3 days from LDP), and those where the LDP was passed 15-35 days before (type B). We applied a microphysical box model (CLaMS-Ice) and a simple freeze drying model (FDM) to simulate the evolution of ice mixing ratios along the trajectories. Type A air masses, with ice mixing ratios larger than 1 ppm, underwent multiple transitions between the solid and gas phase, in good agreement with CALIPSO ice and MLS water vapor observations of around 5 ppm. In contrast, type B air masses showed less agreement with CALIPSO ice and significantly overestimated MLS observations when CLaMS-Ice or FDM were applied. However, water vapor reconstructed from the LDP of the merged back- and forward trajectories agreed much better with MLS, indicating that the wet air masses of type B, observed up to 1.7 km above the CPT, are not representative of the large-scale water vapor distribution detected by MLS. Our results suggest that the full backward and forward evolution of the sampled air masses needs to be considered when inferring stratospheric moistening in the Asian monsoon region. Water vapor concentrations set by LDPs seem to be a better proxy for the stratospheric water vapor budget than rare observations of enhanced water mixing ratios above the local CPT. These observations call into question their applicability to quantify long-term stratospheric water vapor trends.
Blueschists and blue amphibole gneisses in the Nan suture zone, NE Thailand
Authors: Sawasdee Pornchanit , Booth John E. , Skrzypek Etienne , Hauzenberger Christoph A.
Published: February 2023

The Nan River mafic-ultramafic belt was identified when detailed geological mapping of NE Thailand began in the 1970s, and suspected to represent a suture zone. However, in the absence of an obvious ophiolite, its tectonic status was not confirmed until two short papers (Barr et al., 1985 and Barr & Macdonald, 1987) reported the discovery of associated  blueschists. Unfortunately military restrictions on access to detailed topographic maps meant they that they did not state an exact location and the outcrops were “lost” to Thai geologists and no further research was conducted. The two “lost” blueschist localities (south of Nan and west of Uttaradit) were recently re-discovered and related winchite – barroisite schist units identified. Additionally, garnet – glaucophane/riebeckite – white mica – quartz – magnetite – titanite – rutile ± albite ± stilpnomelane bearing gneisses were found among the bedload of a stream cutting through these schists. These gneisses are believed to be derived from “exotic” blocks in a mapped, but poorly exposed thrust sheet of tectonic melange, but to date no in place examples have been found. Similar blueschists/greenschists, gneisses and related garnet – white mica schists have been found further north as cobbles on point bars of the Wa river (west Nan), which cuts through a different section of the mafic – ultramafic unit in a mountainous and inaccessible national park.At both in-place blueschist locations the schists have undergone two episodes of deformation, producing well developed schistosities and tight folding. The blue amphiboles are crossitic in composition. They do not contain garnet nor lawsonite, but abundant epidote and white mica with elevated phengite content. They are interbanded with winchite – barroisite bearing schists. The observed mineral assemblages are poorly suited to apply well established geothermobarometers. However, a PT window of the metramorphic overprint could be established with ca. 450 to 550 °C and 0.6 to 1.0 GPa. Geothermobarometry of the blue amphibole and garnet bearing exotic gneisses from the first blueschist locality (south Nan) indicates peak T conditions of ca. 550°C and a max. P of ca. 1 GPa. Comparable blue amphibole and garnet bearing gneisses from the second locality (Wa river) indicate similar peak PT conditions.In-situ U-Pb zircon analyses from 6 blue amphibole – phengite bearing gneiss samples gave weighted mean 206Pb/238U dates ranging from 312 to 326 Ma, which is interpreted as the age of the protolith. Accessory phases within the blueschists and gneisses include variously zircon, titanite, rutile, allanite and monazite. Planned analysis of these phases should provide the age of HP/LT metamorphism.
Path-dependent landslide geometry analysis
Authors: Li Langping , Lan Hengxing
Published: February 2023

Landslide is not a pure geometric entity, but a mass movement phenomenon. However, in the huge pool of landslide geometry analysis, landslides had been frequently regarded as pure geometric entities, causing that landslide movement characteristics cannot be effectively reflected. For example, many studies had measured landslide length and width by abstracting landslides as rectangles or ellipses. This contribution proposes to do “path-dependent” landslide geometric analysis, and presents relevant methodologies. First, an algorithm for automatic generation of landslide path was developed and coded in a freely available R script called ALPA (Automatic Landslide Path Analysis). Case studies showed that the three-dimensional (3D) paths of landslides with various scales and morphologies can be successfully generated by ALPA. Second, new path-dependent definitions of landslide length (L), width (W) and aspect ratio (L/W) were proposed, in which path-dependent landslide length is measured as the path distance from the landslide crown to its tip along the central line of landslide movement, and path-dependent landslide width is measured as the weighted average lateral extent, across the central line of landslide movement. Specifically, path-dependent landslide width is calculated indirectly through dividing the landslide area by its length. All these path-dependent geometric parameters can be measured either in 3D space or in two-dimensional (2D) space (in the horizontal plane). Case studies showed that path-dependent parameters could be significantly different from path-independent parameters especially for long-narrow and tortuous landslides. Third, the new concept “landslide longitudinal shape”, which describes variation of landslide width along landslide path, is proposed for complementing landslide aspect ratio. Relative width change and relative width fluctuation are defined as parameters quantitatively describing landslide longitudinal shape, and five different types of shape (rectangle, widening, narrowing, spindle and hourglass) are predefined for qualitatively classifying it. Case studies showed that landslide longitudinal shape can provide additional information and therefore is a complement to aspect ratio. Path-dependent geometric parameters do not just describe landslide geometric characteristics, but can somehow help to understand movement characteristics of landslides. We therefore suggest a promotion and further exploration of path-dependent landslide geometry analysis.
Motivations for Engaging in Diversity, Equity, Inclusion and Justice Efforts in the Earth System Science Community
Authors: Haacker Rebecca , Burt Melissa , Montaño Patricia , Vara Marissa , Sloan Valerie
Published: February 2023

In the Earth system sciences, the motivations of organizations for pursuing diversity, equity, inclusion and justice (DEIJ) often center on the benefits to the institution or the science enterprise. The argument is known as the “business case for diversity” in which diverse teams are more creative, set high bars for research, and produce ideas that are more innovative than those produced by homogeneous groups. 
While true, as the sole motivation for DEIJ efforts, the business case is insufficient and does not address the harmful workplaces many marginalized scholars encounter. Institutions will make more progress towards diversifying the STEM workforce by understanding and articulating their ethical responsibilities and transitioning to an equity-centered approach. Emphasizing personal motivations to actively engage in DEIJ work resonates with individuals more, rather than engaging with DEIJ to benefit an institution’s goals. 
Two recent studies in the United States support this argument. The first is an alumni study of postdoctoral fellows at the National Center for Atmospheric Research that explored alumni efforts and motivations for engaging in DEIJ work. The second study surveyed attitudes towards DEIJ efforts among STEM graduate students at Colorado State University who took a course on social responsibility in science. Both studies demonstrate the motivations for scientists to support and get involved in these efforts and indicate that the business case is misaligned with the motivations of students and professionals in STEM. Understanding the attitudes and motivations that individuals have for DEIJ in STEM presents an opportunity for how institutions can best learn from and support these motivations for systemic and sustainable change.
An analysis of 100 years of post-fire streamflow responses of British Columbia watersheds
Authors: Abogadil Karen , Khan Usman
Published: February 2023

Wildfires are becoming larger and more severe due to climate change. This trend affects the forest ecosystem and disrupts many eco-hydrologic processes in forested watersheds. Effects can include rapid runoff responses, increased surface runoff, and elevated erosion, leading to lower water quality and long-lasting effects on hydrologic ecosystem services (drinking water supply or flood regulation). However, post-fire hydrology studies often have variable and contrasting results, making cross-study comparisons difficult. Studies are typically short-term and focused on single wildfire events. Additionally, hydrologic ecosystem services are not always considered. This research has two objectives: to determine accurate indicators for post-fire flow responses; and to develop a flood risk map that considers wildfire history and the hydrologic ecosystem services. The study area includes 336 drainage basins (grouped into five ecozones) in British Columbia, Canada, known for its susceptibility to wildfires and floods. The study analyzes 110 years of wildfire data from 1910 to 2020. Of the 824 wildfires in the study period, over 400 fires were identified with five years of continuous streamflow and precipitation daily flow records. Percent changes in low, high, and peak flows were calculated using pre-fire and post-fire values. Using streamflow, precipitation, wildfire perimeters, land cover and topographic data, statistical analyses were done to determine the most influential watershed characteristic in post-fire streamflow responses. To develop the flood risk map, the same data will be combined with socio-economic and demographic data. Preliminary results suggest differing trends for low, high, and peak flows for the five ecozones in BC, demonstrating the importance of geophysical variables on streamflow response. Results will aid in understanding the effects of climate change over 110 years, specifically the wildfire effects on hydrology in forested watersheds and on the hydrologic ecosystem services provided to nearby communities. The determination of accurate post-fire streamflow indicators will also help water resource managers, urban planners, and other decision-makers allocate resources appropriately for long-term water management and reduce post-fire flood vulnerability.
Applying the AMG Soil Organic Carbon model to assess the carbon trends within French forests
Authors: Houballah Mojtaba , Le Noé Julia , Ferchaud Fabien , Clivot Hugues , Barré Pierre , Guenet Bertrand , Delpierre Nicolas
Published: February 2023

To partially compensate for CO2 emissions, the 4 per 1000 initiative proposed an annual 4‰ soil organic carbon (SOC) stock increase. Yet, the feasibility of such an ambitious target is still under debate. The most efficient way to increase the SOC stocks is to increase the C input to the soil. Yet, knowing how much of an increase of SOC should be an objective is subjected to how much carbon is already stored within soils, and the prediction of the change of carbon pool with time. The objective of this work is to predict the carbon trends in forest soils to be able to better assess the target carbon sequestration. To this end, we use the AMG SOC model to simulate the carbon increase in French forests. AMG is a simple, two-pools model that consider the influence of environmental conditions and litter inputs to simulate the dynamics of SOC. AMG has been designed for agricultural soils, and has proved able to simulate SOC dynamics in croplands but has never been tested on forest soils. The model was run over the French RENECOFOR sites network where SOC measurements have been realized 17 years apart (1994-1996 and 2008-2012) on 95 sites and over which an average increase of +0.35 tC ha-1 yr-1 has been evidenced. We have applied the RockEval method, which mixes machine learning with thermal analysis techniques, in order to initialize AMG, separating the passive from the active carbon pool. We calibrated the model with the aim of simulating the SOC dynamics observed in the RENECOFOR. The results show that even if the model can be successful in predicting the carbon trends locally, there is no general parameterization allowing to reproduce SOC stock evolution trends at the scale of the 95 sites. Our findings suggests that even with a good performance in the case of agricultural soils, there is a need to better represent the litter inputting within the AMG model in the case of forests.
Monthly sea level fingerprints from 1992-2017, utilising ESA CCI Essential Climate Variables in an ensemble modelling framework
Authors: Chuter Stephen , Zammit-Mangion Andrew , Bamber Jonathan , Benveniste Jérôme
Published: February 2023

Sea level rise is one of the greatest socio-economic impacts of climate change in the 21st Century. Whilst global mean sea level is an essential climate variable (ECV) for assessing the integrated response of the Earth system to climate change, regional sea level variability is of primary concern for policy-making decisions and the development of adaptation strategies in coastal localities. Redistribution of terrestrial mass, in the form of hydrological and land ice mass fluxes, partly drives this regional sea level variability due to its impact on the Earth’s gravity, rotation and deformation (GRD), termed ‘Sea Level Fingerprints’ or Barystatic-GRD fingerprints. With increasing mass losses projected from ice sheets and glaciers over the coming centuries, the magnitude and relative contribution of these Barystatic-GRD fingerprints to regional sea level change are expected to increase. As a result, accurately quantifying this phenomenon and its uncertainty is critical when assessing contemporary and future regional sea level variability.Current contemporary Barystatic-GRD fingerprints are typically either calculated using a single mass loading observation source or provide discontinuous coverage since 1992 (the satellite altimetry era). Here, we present a continuous monthly Barystatic-GRD fingerprint product from 1992-2017, computed from an ensemble of mass loadings derived from differing observation techniques. To achieve this, we use the Ice Sheet and Sea Level Model (ISSM) sea level equation solver, which uses a finite element approach to solving the sea level equation at high spatial-temporal resolution, whilst maintaining computational efficiency. This enables us to use an ensemble modelling framework, ensuring the computed Barystatic-GRD fingerprint encompasses the variability between differing observation techniques. Additionally, it allows us to propagate the observation uncertainties into the fingerprint uncertainty in a robust manner. As well as the total Barystatic-GRD fingerprint, we assess the contribution of individual terrestrial components (Antarctica, Greenland, Glaciers, and hydrological mass change). This work is part of the Fingerprinting Approach to Close Regional Sea Level Budgets using ESA-CCI (FACTORS), a European Space Agency Climate Change Initiative Research Fellowship.
Combining optical and SAR remote sensing data for landslide detection and monitoring after extreme climate events: a case study in the northeastern Italian Alps.
Authors: Puliero Silvia , Meena Sansar Raj , Rosi Ascanio , Catani Filippo , Floris Mario
Published: February 2023

Following extreme climate events, a timely and detailed landslide mapping is necessary to determine which areas have been most affected and to support civil protection in rescue operations. Moreover, the monitoring of slope instabilities can lead to an appropriate hazard and risk assessment of the affected areas and to an effective design of remediation works. The integration of optical and SAR remote sensing data acquired by spaceborne sensors plays a key role in these types of evaluations. Optical sensors perform better in terms of spatial and temporal resolution; SAR sensors have the advantage of acquiring images in all weather and light conditions. In this case study, an unstable slope located on the left side of the Boite river in the municipality of Valle di Cadore (northeastern Italian Alps) was investigated after windstorm Vaia event that occurred in October 2018. Medium and high-resolution optical imagery acquired by Sentinel-2 and PlanetScope missions, respectively, have been exploited to calculate NDVI values before and after the event as well as to identify and delineate the most damaged areas using the change detection technique. Then, the processing of Sentinel-1 SAR data through the Small BAseline Subset (SBAS) multi-temporal algorithm allowed for monitoring the evolution of the slope during the post-event. The results show the benefits of combining optical and SAR data to map and monitor the evolution of a slope that was affected by an extreme event such as the windstorm Vaia. In particular, the optical data show the sectors affected by slope instabilities and the time series derived by the SBAS analysis quantifies the displacement rate, emphasizing that the slope is still active. In conclusion, the analysis carried out reveals how these techniques can now become a concrete part of the design of systems to mitigate geological risks derived from hydrometeorological phenomena, whose frequency appears to be increasing due to climate change.
Nighttime atmospheric nucleation driven by marine microorganisms
Authors: Chamba Guillaume , Peltola Maija , Barthelmeß Theresa , Rissanen Matti , Rose Clémence , Iyer Siddharth , Saint-Macary Alexia , Saiz-Lopez Alfonso , Rocco Manon , Safi Karl , Deppeler Stacy , Barr Neil , Harvey Mike , Engel Anja , Dunne Erin , Law Cliff , Sellegri Karine
Published: February 2023

Understanding ocean-cloud interactions and their effect on climate requires that atmospheric new particle formation is characterized. Yet, the process of particle formation from marine biogenic gaz-phase emissions has not been evidenced in the open ocean lower atmosphere, partly due to the naturally low concentrations of these particles in remote oceanic places. Here we show, using new ship-borne air-sea interface enclosures, that new particles are formed in relation to marine micro-biology present in the seawater. The chemical analysis of newly formed clusters with API-ToF-MS shows unexpected results, implicating nucleating coumpounds and pathways that are usually not taken into account in nucleation processes.
Importance of the mesoscale circulation in the energetic of internal tides in two contrasted areas of the North Atlantic.
Authors: Bella Adrien , Lahaye Noé , Tissot Gilles
Published: February 2023

Ocean internal tides are both ubiquitous and important for the transport of tracers and the meridional overturning circulation, because of the mixing in the deep ocean they cause when they break. They are specific kind of internal waves generated when the astronomical tide encounters topographic features, which can propagate over more than a thousand kilometres. This long range propagation leaves opportunities for these waves to interact with mesoscale flows and eddies, which can be of comparable length scale. These interactions are of importance since they impact both the wavelength and the phase of internal tides, making them difficult to map using satellite altimeter once they have lost their coherency with the astronomical forcing. These interactions may also impact the energy budget of the internal tide and the cascade of energy from the astronomical (barotropic) tide to shorter internal waves (down to scales under 1 km), down to 3D turbulence and dissipative scale. In this presentation, we will describe the energy life cycle of internal tides in the North Atlantic basin using outputs from the numerical simulation eNATL60. This simulation has an horizontal resolution of around 2 kilometres and 300 vertical levels. Using a vertical mode decomposition, we investigate the energy budget of the semi-diurnal internal tide and more precisely the exchanges of energy between modes triggered by the topography, the mesoscale flow and the variations of the ambient density field, as well as their time variability.We will focus on two contrasted areas of the North Atlantic: the Azores Islands and the North mid Atlantic ridge with a weak mesoscale activity and strong topographic features, such as seamounts and a ridge, and the Gulf Stream area featuring a strong western boundary current as well as a continental shelf break.In the vicinity of the Azores, topographic induced couplings are of leading order for mode 0 and 1 and induce a substantial transfer of energy from low to high modes. The fraction of energy transferred toward high modes by the topography is almost 100% of the total transfer, but advection by the balanced flow becomes significant in the energy budget for modes 2 or higher.In contrast, in the Gulf stream region, interactions with the mesoscale balanced flow accounts for more than 35% of the energy transfer from low baroclinic modes to high modes, and the mesoscale plays an important role in the energy budget for all baroclinic modes. The most prominent contribution it is the advection by the mean flow: it accounts for 26% of this transfer toward high modes and dominate over topographic scattering for modes 1 to 10.Advection of the internal tides is the dominant contribution of the interaction between internal tides and the mesoscale balanced flow in the two areas. We find that the internal tide only weakly extracts energy from the mesoscale flow and associated buoyancy field in the two areas.
Crustal and upper mantle structure of northern Algeria inferred from a 3-D inversion of teleseismic tomography
Authors: Aichaoui Moussa , Abtout Abdeslam , Bourouis Seid , Bouyahiaoui Boualem
Published: February 2023

The northern Algeria forms the southern edge of the Western Mediterranean Sea that formed within the zone of convergence between the African and Eurasian plates. It is one of the poorest studied areas in the western Mediterranean region, mainly due to the lack of data. The current structure of northern Algeria is the result of the geodynamic evolution that occurred in the western Mediterranean. The few tomographic studies revealed the presence of velocity anomalies beneath the south of the western Mediterranean region. These anomalies suggest the existence of abnormally cold material in the asthenosphere, interpreted as the trace of subducted plunging panels (slab). During the recent decades, the seismological network in northern Algeria has significantly developed, giving rise to a significant increase in the amount of information given by the network database. This development motivated us to investigate the crust and the upper mantle structure beneath the northern Algeria using a non-linear teleseismic tomography method. An overall of 29 stations distributed along the northern part of Algeria have been used to collect 11018 P-waves from 2847 earthquakes recorded over ten years. The proposed model suggests the presence of high-velocity anomalies along of the northern Algeria. We interpreted these abnormal anomalies as a slab teared into two panels. A central segment bending along the Atlasic massif of Hodna and plunging under the Lesser Kabylia. The second segment at the North-East, shifted to the north plunging towards the North-East. A series of Tellian high-velocity anomalies axes mark the limit between the African and the Eurasian plate. The south eastern region covered by our model (Aurès massif) is characterized by a low-velocity anomaly potentially linked to the remnant of the Mesozoic rifting.
Hydrogeoethical questions related to urban groundwater management: the case of Kabul city, Afghanistan
Authors: Hussaini Mohammad Salem , Farahmand Asadullah , Abrunhosa Manuel
Published: February 2023

Groundwater resources are largely invisible and unknown to most people. Hence, unauthorized appropriation of groundwater is not obvious, and its impacts are less evident. It can be said that it is an invisible geo-resource but its impacts and problems are visible to mankind, even if often its source is not recognized. Kabul, the capital of Afghanistan, is the fifth fastest-growing city in the world and rapid population growth and urbanization have created huge pressure on groundwater resources. As a result of a lack of surface water storage and the seasonal variability of river flows, Kabul is among the world's most water-stressed cities as it depends almost entirely on groundwater. The findings of scientific studies reveal that extensive groundwater depletion and degradation of groundwater quality in Kabul city is largely due to anthropogenic factors and it is likely to rapidly continue in the future, particularly in densely populated areas of the city. Here, ethics can play an important role because human behavior is among the main factors creating the problems. So, hydrogeoethical concepts can be assessed and discussed, especially for urban groundwater where human needs (social ethics) and environmental dynamics (environmental ethics) both should be respected. In this study, the most vital questions related to ethical aspects of groundwater management in Kabul city are extracted. To achieve the questions, the water ethics principles and ethical criteria were evaluated concerning the condition of groundwater and the society of Kabul city, as an exercise of applied hydrogeoethics. Finally, six questions are obtained as the result of this study. The response to these critical questions could be a key to solving many dilemmas related to groundwater management in an urban concept. It is recommended to groundwater managers and policymakers explore the answer to these questions and consider the findings in the policies, strategies, and regulations, particularly in urban regions.The questions are as follows:1) What is the level of contribution, obligation, responsibility, honesty, trust, and respect among geoscientists, and engineers related to groundwater management?2) What kind of regulation is adequate for the management of over-abstraction urban groundwater; top-down or self-regulation or a mix of both?3) How education and communication can shape moral motivation for city residents to better groundwater management?4) What is the level of participation of public media (TV, radio, newspapers, etc.) in awareness-raising campaigns related to groundwater conditions?5) Can groundwater abstraction from the deep aquifer (groundwater mining) be an ethical and sustainable policy concerning future generations and environmental ethics?6) How consideration of gender equity and women's participation can be effective in the management of groundwater?