bluuebunny/crossref_metadata_2025 huggingface dataset:
HALO-(AC)3: Airborne Observations of Arctic Clouds in Airmass Transformations
Authors: Ehrlich André , Wendisch Manfred , Klingebiel Marcus , Mech Mario , Crewell Susanne , Herber Andreas , Lüpkes Christof ,   HALO-(AC)3 team
Published: February 2023

Clear indications of the phenomenon of Arctic Amplification include the above-average increase of the near-surface air temperature and the related dramatic retreat of sea ice observed in the last decades. The mechanisms behind these features are widely discussed. Especially the role of clouds and of air mass transports into and out of the Arctic associated with related transformation processes are still poorly understood. Therefore, the HALO-(AC)3 campaign was performed to provide observations of meridional air mass transports and corresponding transformations in a quasi-Lagrangian approach. Three research aircraft equipped with state-of-the-art instrumentation performed measurements over the Arctic ocean and sea ice in March/April 2022. The German High Altitude and Long Range Research Aircraft (HALO), equipped with a comprehensive suite of active and passive remote sensing instruments and dropsondes, was operated from Kiruna, Sweden. The flight pattern covered long distances at high altitudes up to the North Pole probing air masses multiple times on their way into and out of the Arctic. The Polar 5 (remote sensing) and Polar 6 (in-situ) aircraft from the Alfred Wegener Institute operated in the lower troposphere out of Longyearbyen in the lower troposphere over Fram Strait West of Svalbard. Several coordinated flights between the three aircraft were conducted with Polar 6 sampling in-situ aerosol, cloud, and precipitation particles within the boundary layer, Polar 5 observing clouds and precipitation from above roughly at 3 km altitude, and HALO providing the large scale view on the scene following air masses.The observations cover a major warm air intrusion event with atmospheric river embedded bringing warm and moist air far into the Arctic. Multiple cold air outbreaks were characterized in their initial stage close to the sea ice edge with Polar 5 and 6 and in a quasi-Lagrangian perspective with HALO, which allowed to quantify the air mass transformation by changes of thermodynamic profiles, large scale subsidence, and cloud properties over a period of 24 hours. Single events of high latitude Arctic cirrus and the formation of a polar low are included in the data set. The presentation reports on first results of the campaign by illustrating the capabilities of the multi-aircraft operation.
Alkalinity enhancement in intertidal environments: preliminary results of a field experiment
Authors: Mendes Isabel , Lübbers Julia , Cravo Alexandra , Schönfeld Joachim , Correia Cátia , Grasse Patricia , Carrasco A. Rita , Gomes Ana
Published: February 2023

Reducing atmospheric carbon dioxide (CO2) concentrations to combat global warming is one of the greatest challenges of humanity.Marine alkalinity enhancement is a promising carbon dioxide removal measure with high potential to increase oceanic carbon uptake and storage. The natural processes of weathering on land sustains the alkalinity of the ocean and thereby removes CO2 from the atmosphere on geological time scales. The weathering can be enhanced by deploying fine-grained alkaline minerals to coastal areas, to directly supply more alkalinity to near-coastal waters. Nevertheless, the rate of CO2 consumption depends on the minerals used, grains size, temperature, pH, and salinity. During mineral dissolution, nutrients and trace elements are also released, which may affect marine biota. In order to evaluate the CO2 sequestration potential, ensuing biogeochemical and ecological impacts of alkalinity enhancement in intertidal environments, a novel in-situ experiment was installed in the Ria Formosa Coastal Lagoon, southern Portugal.The Ria Formosa is a highly dynamic lagoon system, with daily renewal of water and nutrients through multiple tidal inlets. A succession of salt marshes with varying zonation and faunal communities fringes the lagoon. The experiment was installed in an undisturbed zone colonized with Spartina maritima, in September 2022. The experimental set-up includes three replicate treatments with coarse olivine, fine olivine, coarse basalt, fine basalt, and an untreated control. Lagoonal, supernatant, and porewater waters are sampled from each treatment every month and analysed for temperature, salinity, oxygen concentration, pH, total alkalinity, nutrients, and trace metals. Preliminary data show an increase in total alkalinity in the supernatant and porewaters shortly after minerals deployment, by 0.36 and 2.05 mmol kg-1 on average, relative to the control. Lower values of total alkalinity were recorded in December 2022, followed by markedly lower salinities after heavy rainfall in the study area. The experiment will run over two years and monthly sampled for water properties. For monitoring potential biodiversity changes, sediment samples are analysed for faunal and floral composition. Results of this novel field experiment will provide strategic knowledge on the benefits and risks of alkalinity enhancement in intertidal environments.Acknowledgement. Research supported by the Portuguese Science Foundation, with the projects PTDC/CTA-CLI/1065/2021, UID/00350/2020CIMA and contracts DL57/2016/CP1361/CT0009, DL57/2016/CP1361/CT0002 and CEECINST/00146/2018/CP1493/CT0002.
A global meta-analysis of methane, nitrogen dioxide emission and soil organic carbon changes of grazing grassland soil under different grassland management
Authors: Li Tong , Pan Genxing
Published: February 2023

Exploring how methane(CH4), nitrogen dioxide(N2O) and soil organic carbon(SOC) content change under different grassland management is significant for mitigating global warming. We conduct a global meta-analysis to figure out the responses of CH4, N2O and SOC content to different management and Random Forest models are used to explore the most important driving factors of the changes. Our results show that grazing can cause SOC lose except in the climate zone Arid, which can increase the SOC content. The emission of CH4 of grazing grassland increases under all grazing intensities and all climate zones. By comparison, the emission of N2O decreases because of grazing activity except the light grazing intensity. As for fertilizer application, all types of fertilizers lead to more CH4 and N2O emission. Among all the fertilizers，cattle urine leads to the most soil N2O emission and chemical fertilizer causes the most CH4 emission. When adding inhibitors, the mitigation effects are significant. They can decrease CH4 and N2O emission 35% and 25% respectively. As for the variables importance in grassland soil greenhouse gas emission, the results of Random Forest models show that the most three important variables in most models are initial SOC content, mean annual precipitation (MAP) and the mean annual temperature(MAT).This study highlights that moderate grazing is better for nature grazing grassland when considering the comprehensive mitigation effect and removing livestock excrement or adding inhibitors are effective ways to mitigate non-CO2 greenhouse gas emission from soil.
Energy Conversion Associated with Flux Transfer Events at Earth’s Magnetopause
Authors: Dahani Souhail , Lavraud Benoit , Génot Vincent , Toledo-Redondo Sergio , Kieokaew Rungployphan , Fargette Naïs , Gershman Daniel , Giles Barbara , Torbert Roy , Burch Jim
Published: February 2023

Flux Transfer Events (FTEs) are transient phenomena generated at the dayside magnetopause as a result of magnetic reconnection. FTEs have a significant role in the transfer of momentum and energy into the magnetosphere. We study here, in a multifluid framework, how the energy is converted within FTEs and their surrounding plasma. In particular we investigate how the plasma gains or loses kinetic energy through electric and/or pressure gradient terms. We also investigate the terms that control how the internal energy of the plasma is gained or dissipated through the pressure work term. Using observations from Magnetospheric MultiScale (MMS), we perform a statistical study based on an existing FTE catalog (Fargette et al., 2020). We analyze FTEs with or without internal current sheets. We discuss the contribution of the different terms in the energy conversion process separately for ions and electrons and as a function of location within the FTE. We analyze and compare the results found for FTEs’ intervals with magnetosheath intervals (Wang et al. 2021), taking into account their locations, using probability distribution functions of the various energy terms measured in each interval. This work contributes to a better understanding of energy conversion processes associated with FTEs at the magnetopause.
Uncertainty in Sahel precipitation change: a storyline approach
Authors: Monerie Paul-Arthur , Biasutti Michela , Mignot Juliette , Mohino Elsa , Pohl Benjamin , Zappa Guiseppe
Published: February 2023

Future changes in Sahel precipitation are uncertain because of large differences between projections of various climate models. We assess the effect of climate change on Sahel precipitation in summer and for the end of the 21st century. We show that uncertainty in Sahel precipitation is associated with uncertainty at simulating future changes in surface air temperature over the northern Hemisphere. We point out the Atlantic Ocean and Euro-Mediterranean surface air temperature as drivers of the Sahel precipitation change uncertainty. We use a storyline approach, a statistical method, to construct scenarios of changes in Sahel precipitation, whose differences only depend on future changes in Atlantic Ocean and Euro-Mediterranean surface air temperature. We show that uncertainty in changes in Atlantic Ocean and Euro-Mediterranean surface air temperature explains up to 50% of Sahel precipitation change uncertainty. The approach also allows selecting models to better understand uncertainty in Sahel precipitation change, focusing on the mechanisms at play. We suggest that reducing uncertainty in the future warming of the North Atlantic and the Euro-Mediterranean areas would then allow reducing uncertainty in future changes in Sahel precipitation.
Small scale ionospheric disturbances as seen by the LOFAR
Authors: Mevius Maaijke , Beser Kasia
Published: February 2023

The LOFAR radio telescope consists of a large network of stations distributed across Europe, with a dense core in the east of the Netherlands. Each station consists of multiple antenna fields operating at frequencies between 20 and 80MHz and 110 and 240MHz. At these frequencies the ionosphere has a major impact on the astronomical observations, that needs to be corrected for.  This ionospheric calibration, at first order mainly a phase effect, provides valuable information about the ionospheric density variations above the telescope. We report on the use of the calibration solutions to extract the ionospheric information on structure, dominant direction and variability. In particular, we investigated the data recorded with the Dutch array, consisting of a core of 48 stations all within a 3 km diameter circle and another 14 remote stations with baselines up to 100 km, operating between 110 and 170 MHz.  The different baselines give access to different scales in the ionosphere. Furthermore, we present, for the same data, an imaging technique that allows direct imaging of larger scale gradients in the ionosphere.
Modelling the efficacy of catchment remediation measures for reducing sediment & nutrient exports under future climate trajectories 
Authors: Wynants Maarten , Hallberg Lukas , Bieroza Magdalena
Published: February 2023

The European Green Deal has the ambition to reduce nutrient losses from agricultural catchments with 50%. In the context of a changing climate, there is an increasing need to evaluate the efficacy of catchment remediation measures and reduction in fertilisation. In this study, we set-up a daily discharge and nutrient load model for two Swedish agricultural headwater catchments using Hydrological Predictions for the Environment (HYPE). The daily model was calibrated and validated using high-frequency sensor data and flow-proportional samples analysed for nutrient and sediment concentrations. Multiple catchment remediation scenarios were run under three downscaled climate models and three Representative Concentration Pathways (RCP 2.6, RCP 4.5, and RCP 8.5). The model predicted that Inorganic Nitrogen loads will decrease in the latter half of the 21st century under RCP 4.5 and RCP 8.5 driven by increased denitrification under higher temperatures. Moreover, under all RCPs, an increase in Particulate Phosphorous and sediment loads is forecasted due to increased rainfall intensity. Decreasing the amount of mineral fertilisation only resulted in decreased Inorganic Nitrogen loads, but had no effect on Total Phosphorous loads. Catchment remediation measures were most effective for reducing Total Phosphorous loads. However, large portions of agricultural catchments will need to be converted to floodplains or wetlands in order to achieve significant load reductions and offset the predicted increases under future climatic trajectories.
Calving Model Intercomparison Project (CaMIP): Overview and preliminary results
Authors: Jordan James , Pattyn Frank
Published: February 2023

Ice shelf calving is responsible for roughly half the mass lost by Antarctic Ice Shelves and is of vital importance for determining ice-shelf stability. Despite this, it is currently poorly represented in numerical models and as such has seen limited inclusion in numerical simulations of the future Antarctic Ice Sheet. A first step towards improving this situation is assessing the capabilities and limitations of current numerical models regarding calving. The Calving Model Intercomparison Project (CaMIP) is, therefore, being undertaken to address this issue as part of the EU funded Horizon 2020 project PROTECT.We present here an overview of the project, as well as preliminary results from the first round of experiments by a range of participating modelling groups from across the cryospheric community.
A UAV-based rut depth detection - A potential for evaluating soil compaction on farmlands
Authors: Ansah Christabel , Rettig Robert , Storch Marcel , Jarmer Thomas
Published: February 2023

In recent decades, due to the increasing weight of agricultural machineries, undesirable soil compaction has become a severe factor for soil degradation. It does not only have negative ecological, but also economic effects. Successfully detecting, monitoring and predicting depths of ruts that were used by heavy vehicles can potentially reduce soil compaction. A crucial task is to generate real-world data at site-specific locations. UAV-based approaches have the advantage of providing sufficient spatial coverage and resolution to assess vital information, which can be used to directly evaluate the compaction resulting from the utilization of these heavy machineries. This information could be used for agricultural predictions, optimized routing and best time for treatments, soil regeneration purposes and many more. Therefore, the aim of this research was to spatially detect the depth of ruts, caused by heavy farm machineries on agricultural fields with consumer-grade Unmanned Aerial Vehicles (UAVs).We therefore created a semi-automatic processing pipeline for UAV based data. The georeferenced RGB orthomosaic was used to spatially predict lanes, in the early stages of the crop cycle, by employing a Machine Learning approach. This prediction was subsequently used to extract the height information of the rut and the surrounding area from the SfM (Structure from Motion) Digital Elevation Model. As a reference method for the absolute height information, we compared this DEM (DJI Phantom 4) to the UAV - LiDAR derived DEM (RIEGL miniVUX-1UAV). For both systems, no substantial difference in the quality of the evaluated compaction depth was observed. This allows the use of low-cost UAV RGB systems to contribute to the ongoing research on soil compaction.
Characterization of Shalbatana Vallis landslides
Authors: Soldano Matilda , Allemand Pascal
Published: February 2023

Shalbatana Vallis is a valley located in the Oxia Palus quadrangle, characterized by a simple system and a homogeneous coverage. Shalbatana vallis flows into the Chryse Planitia basin, alongside Ares Vallis, Kasei Valles, Simud Valles and Tiu Valles. The valley is affected in different points by landslides with various surfaces and elongations. Landslides on Mars are a topic already studied by other authors. However, the problem of the dynamic of such structures remains debated. The landslides of Shalbatana Vallis occurred in a homogeneous lithology and in a valley with a quite constant depth. We first present the ages of the landslide and discuss the age distribution. The, we present a geometrical analysis of the landslides (surface, elongation, volume, runout, etc….) and use these parameters to constrain some dynamical properties (possible velocity, possible loss of volatiles) and to discuss possible triggering mechanisms.
Constraining the rates of olivine crystal growth with diffusion chronometry
Authors: Stroh Annalena , Moulas Evangelos , Botcharnikov Roman
Published: February 2023

Xenocrysts in magmatic rocks are often found having gradients in their composition. These compositional gradients are commonly interpreted as the result of mass fractionation during crystal growth and it is quite common that these gradients are also influenced by intra-crystalline chemical diffusion. Since the interplay between element diffusion and crystal growth in the magma controls the final composition of magmatic minerals, it is not possible to uniquely constrain the high-temperature history of a zoned crystal. To address this problem, we present a numerical model that can be used in an inverse manner to constrain the rate of olivine growth in basaltic magma. The model addresses a classic moving boundary problem, whilst solving the intra-crystalline diffusion of Ca in olivine. Our model is created to account for the growth of a spherical olivine crystal in a finite (or infinite) reservoir. The diffusion equation is solved with a forward Euler scheme and we use a conservative, regridding approach to account for changes in crystal size. The model was tested against experimentally determined olivine growth rates. Our results show that the inferred growth rates agree within an order of magnitude to the results from experiments at fixed pressure, temperature and oxygen-fugacity conditions.
Mesozoic evolution of the Atlantic-Tethys junction: a kinematic description
Authors: Frasca Gianluca , Manatschal Gianreto
Published: February 2023

Diverging plates are reconstructed through well-defined time-steps and direction of motion thanks to oceanic magnetic anomalies and fracture zones. None of these two oceanic features can nevertheless be used if the divergent boundaries are reactivated in orogenic belts. Convergence erases indeed the dense oceanic material and the related kinematic markers and leave as main witnesses suture zones and associated remnants of the former continental margins. The pre-orogenic plate template of the Alps remains debated for this reason, leading to debate on the size of subducted oceanic domains, and on the complex paleogeography at the Tethys-Atlantic junction. Unravelling size and fate of the pre-orogenic domain remains difficult and asks for a new, holistic restoration approach. Here we use a rift domain approach that enables us to quantify width and formation ages of margins of the Iberia-Eurasia-Adria-Africa plate boundaries. We jointly use a global kinematic restoration software (Gplates) and new rift concepts that allow us to propose a tight fit restoration and evolution of the Atlantic Tethys junction during the Mesozoic. Kinematic restorations of the Mesozoic evolution of what is now the Western Mediterranean must build on independent approaches. A first approach is the correct restoration of the major surrounding plates. A second approach is the restoration of the intra-continental extension accommodated in reactivated rifted margins that can be in the order of several hundreds of kilometers. Remnants of the former margins allow to define so-called building blocks and appear as a good base for restoration where vestiges of a standard oceanic crust are missing.
New constraints from structural data and U-Pb calcite geochronology on La Collada fluorspar ore body (Asturian basin, NW Spain)
Authors: Granado Pablo , Ruh Jonas B. , Guillong Marcel , Rodríguez-Terente Luis
Published: February 2023

The Permian–Mesozoic Asturian (NW Spain) hosts a series of world-class fluorspar deposits - a critical raw material for the EU - with more than 15 Mt. extracted to date. Asturian fluorspar deposits are hosted in silicified Paleozoic and Triassic carbonate rocks, spatially associated with the fault-bound margins of the basin. The Asturian fluorspar deposits show an important structural and lithological control, being hosted in fault-fill veins, jogs and breccias associated with steeply-dipping extensional faults and related folds, and strata-bound bodies replacing carbonate rocks. The general paragenesis comprises fluorite, calcite, quartz, (±) barite, and minor sulfides including pyrite, sphalerite, chalcopyrite, (±) galena. Formation of these fluorspar deposits has been assigned to the Permian volcanic activity during the extensional event following the Variscan orogeny, or the Mesozoic opening of the Atlantic realm.For this study, we have sampled and measured the orientation of the main ore body at La Collada underground works. The ore body is hosted in a fault-fill vein moderately dipping to the SSW (mean plane is 214/47; n=41), ranging in thickness from a few meters to 15m. Observed sub-vertical veins of calcite are kinematically compatible with the main SSW-dipping fault-fill vein, and suggest concomitant ore deposition and extensional faulting. Laminated textures and localized high-dilation breccias in the main fault-fill vein suggests multi episodic fault activity associated with fluid overpressures (fault-valving?). S/C structures and fault slickensides (n=6) indicate oblique right lateral reactivation. Three representative samples from the main fault-fill vein were taken for U–Pb dating by LA-ICP-MS. Calcite spot analysis yielded two age populations (155Ma, 131Ma.) thus suggesting multiepisodic precipitation of calcite, and a potential open system. Obtained radiometric ages are consistent with rift initiation in the Asturian basin, and opening of the Bay of Biscay since Upper Jurassic times. Coupled with structural geology and textural analysis, LA-ICP-MS U-Pb dating of hydrothermal calcite aids in constraining the timing of fluid-flow events and fault activity responsible for ore deposit formation and re-mobilization, and refines the regional context of the Asturian fluorspar deposits.
Is the Pampean flat-slab responsible for the differences in post-seismic motions between Maule and Illapel earthquakes?
Authors: Klein Emilie , Boulze Hugo , Vigny Christophe , Fleitout Luce , Garaud Jean-Didier
Published: February 2023

Ever since the Maule earthquake (Mw8.8, 2010), a quick vertical uplift is measured thanks to GNSS in the Andes, facing the rupture zone (~250 km to the trench). Models built for the Maule earthquake [Klein et al. 2016] have highlighted that a low-viscosity channel is required to explain the post-seismic uplift. This channel is located along the slab between 50 km and 130 km depth and has a viscosity of a few 1017 Pa.s - lower than in the asthenosphere, 1018 Pa.s. After the Illapel earthquake (Mw8.3, 2015), simple observations on GNSS time-series show that no uplift occurred in the Andes at an equivalent distance to the trench than in the case of the Maule earthquake. The subduction in the Illapel region is characterized by a flat-slab (called the Pampean flat-slab) in contrast with the normal-dipping subduction in the region of Maule.Here, we investigate what is the impact of the Pampean flat-slab on the post-seismic deformations of the Illapel earthquake. In particular, we try to understand  whether the presence of the flat-slab inhibits the effect of the low-viscosity channel. For that purpose we compare GNSS vertical displacements with predictions in both regions of Maule and Illapel from a 3D spherical finite-element model that accounts for the slab geometry of the Chilean subduction zone.
Lag in catchment vegetation response to water availability and atmospheric dryness
Authors: Abeshu Guta Wakbulcho , Li Hong-Yi
Published: February 2023

Catchment water availability for vegetation use (i.e., catchment wetness) and atmospheric water demand (i.e., vapor pressure deficit, VPD) are two of the major abiotic factors that control the intra-annual variability of catchment vegetation carbon uptake (i.e., GPP). This study analyzes 380 catchments distributed across the contagious US to explore the causality and interconnectedness between these two factors and catchment vegetation productivity. We use indices to represent seasonal climatic, hydrologic, and vegetation characteristics: Horton Index (HI), ecological aridity index (EAI), evaporative fraction index (EFI), and carbon uptake efficiency (CUE). Further, we employ statistical methods, including circularity statistics, spearman's correlation, Granger's causality, and PCMCI+, to depict connections between catchment wetness, atmospheric dryness, and vegetation carbon uptake. Our results indicate that catchment water supply-productivity and water demand-productivity cause-effect relations occur within a maximum span of two months (i.e., ±1 month from GPP). The annual scale relationships of these variables are more likely driven by a few dominant months. Moreover, attributed to the lag, hysteresis exists between GPP and catchment wetness and between GPP and VPD. The narrowest hysteresis develops in dry catchments (i.e., HI→1, EFI→1, and CUE have low intra-annual variability), and the wide hysteresis develops in catchments where HI and EFI have strong intra-annual variability, and their seasonal patterns are not in phase. For catchments that are not permanently under water-limited or energy-limited conditions, vegetation is under hydrologic stress (i.e., high HI) during the peak growing period. GPP is at its highest in this period, and CUE is out of phase with HI and in phase with EFI. These findings support the need for developing a direct functional framework between catchment water supply, atmospheric demand, and vegetation productivity. Such a framework can help us track normal and extreme hydrologic and climatic signals' effect on catchment vegetation and vice versa.
Soil CO2 and N2O emissions in Sahelian Silvopastoral systems: spatial distribution and annual budget estimation
Authors: Agbohessou Yélognissè , Delon Claire , Grippa Manuela , Mougin Eric , Ba Seydina , Ngom Daouda , Roupsard Olivier
Published: February 2023

Silvopastoral systems (SPS) are one of the most common livestock production systems in the Sahel. They are composed of a mix of trees, pastures, and livestock in the same area. Known for providing several beneficial services compared to traditional pastures, SPS can release or absorb greenhouse gases. So far, our understanding of the magnitude and spatial distribution of greenhouse gas emissions in Sahelian SPS is subject to many uncertainties. This is mainly due to a lack of experimental and modelling studies focused on the region.We use a process-based model, STEP-GENDEC-N2O, that couples vegetation growth, biogeochemistry, and gas emissions to investigate the spatial and temporal pattern of carbon dioxide (CO2) and nitrous oxide (N2O) emissions from soil and estimate their annual budget in the Sahelian SPS. After model validation using in-situ data collected at the Dahra site (north-western Senegal), simulations were performed on the entire Sahelian area (latitude: 13°N to 18°N; longitude: 18°W to 20°E) divided into 18271 grid cells of 0.1° x 0.1°, from 2010 to 2021. Input variables were extracted from different datasets available at global or regional scales.We found that the spatial pattern of CO2 and N2O emissions from soils in Sahelian SPS can be mainly explained by the spatial distribution of soil properties (soil temperature, soil sand, and clay content), climate, and animal load. The overall estimated CO2 and N2O emissions from Sahelian SPS during the 2010-2021 period were 0.054 ± 0.005 Tg C yr-1 (1 Tg = 1012 g) and 0.046 ± 0.008 Tg N yr-1, respectively. These values are relatively low compared to other estimates for grazing and cropping systems in other regions. Mapping CO2 and N2O emissions from soils in SPS at the Sahel-wide scale helps identify emission hotspots in order to establish more effective mitigation strategies and management policies for Sahelian SPS.
Modelling Climate Migration in Southeast Asia due to Sea-Level Rise
Authors: Manimaran Sonali , Lallemant David
Published: February 2023

Southeast Asia (SEA) is among the regions that are most at risk of experiencing climate change-induced human migration. It is home to more than 675 million people, many of whom reside in lower-middle income countries, with pre-existing social vulnerabilities and poverty, largely in low-lying coastal cities. SEA regularly experiences natural hazards, including floods and typhoons, whose impacts are expected to be magnified by climate change, and compounded by newer hazards, such as sea-level rise (SLR). Some level of climate migration is inevitable in this region, but with appropriate management, the scale of migration can be reduced and can serve as an effective adaptation strategy.To better understand the scale of SLR-induced migration, as well as to identify the areas and population groups most at risk, this study employs a radiation model, which has previously been shown to be successful in predicting internal migration flows. In this study, the radiation model is used to predict the migration flows in SEA due to SLR, and to identify hotspots of sending and receiving regions of migrants. Specifically, future migration flows in Indonesia and Philippines are modelled from 2050 to 2100, looking at baseline non-climate migration, as well as SLR-induced climate migration, for a range of Representative Concentration Pathways (RCPs) and population growth projections. Preliminary results show a ~25% increase in migrant outflows under SLR scenarios relative to baselines, and a ~50% increase in inter-provincial migration rates. This indicates that SLR-driven migration will be significant for these countries and needs to be managed in a way that does not exacerbate existing vulnerabilities. This entails implementing in-situ adaptation measures in locations where it is still feasible, and facilitating relocation where in-situ adaptation would not be feasible. The radiation model is an effective way to predict migration flows at sub-national and national scales, and can be applied to other countries in SEA, given that the data inputs for the model are readily available.
NEMO v4.2 in regional climate modelling - towards climate projections for the German coasts
Authors: Ehlers Birte-Marie , Meyer Janna , Düsterhöft-Wriggers Wibke , Maurer Vera , Janssen Frank
Published: February 2023

The “German Strategy for Adaption to Climate Change” (DAS) is the political framework to climate change adaption in Germany. The DAS core service “Climate and Water” provides monitoring and projection data to evaluate requirements for climate change adaption. Using the state of the art ocean model NEMO v4.2 a setup is developed to provide projection data for the target regions North Sea and Baltic Sea with focus on the German coastal region and its estuaries.The setup includes the entire North-West-Shelf to take into account the impact of the North Atlantic weather systems on the dynamics of the seas and the cross-shelf transport. An adjusted bathymetry based on up-to-date measurements of the sea floor from the EMODNET network is introduced and studied with regard to its tidal behaviour, especially in the German Bight. The setup is also tested for its response on the use of different data sets of boundary data for tides, temperature and salinity, providing insights into the influence of temporal resolutions of boundary data on projection results.Validation work is presented with focus on the sea level at the German coasts and water exchange between the North Sea and the Baltic Sea through the Danish Straits. Furthermore special attention is payed to the thermal stratification and to the seasonality and thickness of sea ice.First results and a short overview on the coupling of NEMO to the atmospheric model ICON for the EURO-CORDEX domain will complete the presentation. An outlook on further development steps towards high-resolution nested grids and the utilisation of a wetting-and-drying scheme will be given.
Two classes of magnetotail Dipolarization Fronts observed by MagnetosphericMultiscale Mission: A statistical overview
Authors: Alqeeq Soboh , Le Contel olivier , Canu patrick , Retinò Alessandro , Chust Thomas , Mirioni Laurent , Chuvatin Alexandre , Nakamura Rumi , Ahmadi Narges , Wilder Frederick , Gershman Daniel , Khotyaintsev Yuri , Lindqvist Per Arne , Ergun Robert , Burch James , Torbert Roy , Fuselier Stephen , Russell Christopher , Wei Hanying , Strangeway Robert ,   MMS team
Published: February 2023

We carried out a statistical study of 132 Dipolarization Fronts (DFs) events detected by the Magnetospheric Multiscale mission (MMS) during the full 2017 Earth’s magnetotail season. We found that two DF classes can be distinguished: class I (74.4%) corresponds to the standard DF properties and energy dissipation whereas a new class II (25.6%), which includes the six DF discussed in S. Alqeeq et al. 2022, corresponds to a bump of the magnetic field associated with a minimum of the ion and electron pressures and a reversal of the energy conversion process. For both classes we found that ions are mostly decoupled from the magnetic field by the Hall fields. The electron pressure gradient term is also contributing to the ion decoupling and likely responsible for an electron decoupling at DF. Both DF classes show that the energy conversion process in the spacecraft frame is driven by the diamagnetic current dominated by the ion pressure gradient. In the fluid frame, it is driven by the electron pressure gradient. In addition, we have shown that the energy conversion processes are not homogeneous at the electron scale mostly due to the variations of the electric fields for both DF classes.
Soil organic matter stability decreases with increasing urbanization in highly weathered rainfed tropical arable soils
Authors: Asabere Stephen Boahen , Don Axel , Peplau Tino , Sauer Daniela
Published: February 2023

Urbanization is a major land use change factor affecting soils. There is little understanding of how expansions of tropical West African cities have affected soil organic matter (SOM) composition and dynamics. In such cities, urban agriculture is common, playing an essential role in food security and urban sustainability. However, tropical soils tend to have low nutrient contents and cation exchange capacity. Thus, management strategies that enhance soil fertility and carbon (C) sequestration are needed. Developing such strategies requires a thorough understanding of how SOM dynamics alter in response to urban growth. Here, our objective was to assess how urbanization has affected the relatively stable mineral-associated-SOM (MAOM) and the labile particulate-SOM (POM) fractions in rainfed urban arable maize fields of Kumasi, a typical expanding city in Ghana (West Africa).Using a grid-based satellite approach, and keeping other factors constant (including climate, topography, parent material and soil type), we took topsoil samples (0–10 cm) along an urban-intensity (UI) gradient, distinguishing: (i) low UI, located >400 m away from any primary road and having been under urbanization for <30 years, (ii) mid-low UI, located ≤400 m from a primary road and having been under urbanization for <30 years, (iii) mid-high UI, located >400 m from primary road and having been under urbanization for ≥30 years, (iv) high UI, located within ≤400 m from a primary road and having been under urbanization for ≥30 years. SOM fractions were isolated from the soils using a size separation approach, whereby the sand-sized fraction (0.063 - 2 mm) was regarded as POM and the clay- and silt-sized fraction (<0.063 mm) as MAOM. Prepared samples were ultimately analyzed for SOC using a Leco temperature ramp C analyzer, where a temperature threshold of 600 ºC was used to separate organic from inorganic C.We found that mean SOC contents of the POM fraction increased markedly from 7.7 g kg-1 in the low UI topsoils to 13 g kg-1 in their high UI counterparts, suggesting an increase in POM with increasing urbanization. This trend was not observed for the MAOM that showed SOC contents of 4.5, 4.1, 4.9, and 4.1 g kg-1 for the low, mid-low, mid-high, and high UI topsoils, respectively. Moreover, the share of SOC contents of POM in the bulk SOC increased from 51% in the low UI topsoils to 64% in the high UI topsoils, whereas that of MOAM decreased by 6% from 31% to 25%, respectively. These findings suggest that while there is evidence of strong anthropogenic contributions of SOM to urban arable soils, urbanization does not seem to promote SOC storage in the relatively stable MAOM fraction. Consequently, rainfed urban arable soils in Kumasi will need management interventions for keeping appropriate long-term SOM levels to maintain soil functions.       
Effect of tectonic closure of the American Seaway on oxygen minimum zone in the tropical Pacific from model simulations
Authors: Khon Viacheslav , Hoogakker Babette , Schneider Birgit , Segschneider Joachim , Park Wonsun
Published: February 2023

The world’s largest oxygen minimum zone (OMZ) resides in the eastern tropical Pacific where poorly ventilated “shadow zone”, created by stagnant tropical cyclonic gyre is complemented by intensive biological consumption of dissolved oxygen, thereby promoting oxygen deficiency in this region. The present-day continental configuration with the presence of the Isthmus of Panama prevents water mass exchange between the tropical Pacific and the Caribbean Sea, shaping the climate and marine biogeochemistry features in the eastern tropical Pacific. The tectonic closure of the American Seaway during the mid-Miocene to mid-Pliocene epoch (~16-3 Ma BP) is thought to be a key factor for the development of stagnating conditions in the eastern equatorial Pacific leading to emergence of tropical Pacific OMZs . This study aims at investigating the impact of the CAS opening on the large-scale ocean circulation and oxygen minimum zone in the tropical Pacific. To this end, we performed a series of sensitivity experiments with the global climate model KCM where a sill of the open CAS was set at different depths, ranging from shallow to deep levels. Our results confirm previous studies that Panamanian gateway closure during the Pliocene may have led to an intensification of the Atlantic Meridional Overturning Circulation (AMOC) due to a termination of fresh-water supply from the tropical Pacific to the North Atlantic. It was found that the CAS opening drives eastward subsurface flow in the northern tropical Pacific. This, in turn, facilitates stronger west-to-east oxygen supply and subsequent overall oxygen enrichment in the subsurface Pacific waters with strongest anomalies observed in the eastern tropical Pacific. In addition, the marine net primary production is slightly weakened in this region due to an export of nutrients to the Caribbean Sea through the open Panamanian gateway. This, in turn, leads to a weaker export of particulate organic carbon towards the ocean interior, and, therefore, to lower biological consumption of oxygen in this region.
Testing the splitting intensity methodology to retrieve average, dipping, and depth dependent anisotropy from a complex subduction model
Authors: Confal Judith M. , Baccheschi Paola , Pondrelli Silvia , VanderBeek Brandon P. , Karakostas Foivos , Faccenda Manuele
Published: February 2023

Seismic anisotropy measurements provide a lot of information on the deformation and structure of the Earth’s interior, in particular of the upper mantle. Conventional methods of measurement of anisotropy have their limitations, especially regarding depth resolution. Splitting intensity (SI) is a seismic observable, related to the amount of energy on the transverse component waveform and, to a first order, it is linearly related to the elastic perturbations of the medium through the 3-D sensitivity kernels, that can be therefore inverted, allowing a high-resolution image of the upper-mantle anisotropy. Starting from synthetic SKS waveforms, we first derived high-quality SKS splitting intensity measurements; then we used the splitting intensity data as input into tomographic inversion. This approach enables high‐resolution tomographic images of horizontal upper‐mantle anisotropy through recovering vertical and lateral changes in anisotropy and represents a propaedeutic step to the real cases of subduction settings. Additionally, this approach was able to detect regions of strong dipping anisotropy by allowing a 360° periodic dependence of the splitting vector. Single and thick layers of dipping angles between 30 and 60° are clearly represented with a high dt2 value, while double layers or nearly vertical dips are more difficult to identify.
Introduction of detection and monitoring methods in coal field fire
Authors: Yuan Yu
Published: February 2023

Accurate identification of high temperature area of coal fire is the premise of coal fire control, coal fire monitoring is the test of coal fire control effect, coal fire detection and monitoring are the key and difficult points of coal field fire fighting engineering. This report first introduces the characteristics of high temperature anomalies in coal fire areas, Abnormal characteristics include: abnormal temperature, spontaneous potential, magnetic field intensity, resistivity, gas content. and then proposes targeted detection and monitoring methods on this basis. Commonly used methods include: Temperature measurement method, thermal infrared remote sensing method, natural electric field method, magnetic method, high density resistivity method, transient electromagnetic method, gas component measurement method, radon gas measurement method, and so on. Finally, comprehensive comparative analysis is adopted to achieve the purpose of identifying and monitoring the fire area.
Hyperspectral sensing as a tool for smart environmental monitoring in mine waste management
Authors: Flores Hernan , Rudoplh Tobias , Möllerherm Stefan
Published: February 2023

The use of hyperspectral imaging (HSI) at different scales has become a big ally for a large range of applications in remote sensing, especially within the mining life cycle. In this contribution, we explore the use of HSI sensing, particularly to monitor mine waste at different constellations that might face environmental damaging phenomena: Acid Mine Drainage (AMD). Failure to accurately monitor and remediate such a complex process, leads to long-term impacts on ecosystems and human health, in addition to significant financial consequences and reputational damage to operators. We propose a workflow to integrate hyperspectral visible to near-infrared (VNIR) data, together with mineralogical and geochemical data to precisely map the extent of acid mine drainage using machine learning algorithms. Collected data from the field and further laboratory analyses on a few specimens provide the ground-truth and training data to support the proposed mapping algorithms. Results consist of semi-quantified concentration of dissolved metals, physicochemical properties in water bodies, and associated AMD minerals sub-products (e.g., goethite, jarosite, schwertmannite) within mine waste materials, as well as mineralogical characterization for predictive modeling at laboratory scale.  Regardless of the scale of acquisition, spectral imaging represents a cost-effective tool to enhance the quality of classical environmental analyses both in active and post-mining scenarios, which can increase the overall accuracy of the monitoring, allowing frequent and multi-temporal observations to reveal risk scenarios, take fast corrective actions and keep a continuous control.
Analysis of type III radio emissions observed by the Solar Orbiter spacecraft close to their source locations
Authors: Formánek Tomáš , Píša David , Souček Jan , Santolík Ondřej , Vecchio Antonio , Maksimovic Milan , Rodríguez-Pacheco Javier , Horbury Timothy , Owen Christopher John
Published: February 2023

Type III radio emissions are often observed by the Solar Orbiter spacecraft in the solar wind. They arise from a mode conversion of Langmuir waves generated by electron beams ejected from the Sun. In this study, we analyze sources of type III radio emissions that occurred after July 2020. We use data from the Radio and plasma waves (RPW), Energetic particle detector (EPD), Magnetometer (MAG), and Solar Wind Analyzer (SWA) instruments. We identify in-situ type III events and examine various parameters that may have influenced their generation mechanism. We use the maximum amplitude (MAMP) data product from the Time Domain Sampler (TDS) receiver of the RPW instrument for continuous tracking of Langmuir wave packets. For in-situ type III events throughout the Solar Orbiter mission, we study the wave polarization of the locally generated Langmuir waves measured in the Y-Z plane of the spacecraft reference frame. Using data from the EPD instrument, we obtain electron beam velocities for several in-situ events. We show that the electron beam velocity for those events is higher than predicted by previous studies.