bluuebunny/crossref_metadata_2025 huggingface dataset:
Steady-state of the Martian induced magnetosphere and its rapid response to interplanetary magnetic field rotation
Authors: Lin Rentong , Huang Shiyong , Yuan Zhigang , Wu Honghong , Jiang Kui , Wang Yuming , Zhang Tielong , Xu Sibo , Dong Yue , Xiong Qiyang , Huang Huxing
Published: March 2024

The induced magnetosphere in non-magnetized planets or moons, formed by the interaction between their atmosphere and stellar wind or planetary wind, is generally modulated by external magnetic field. The magnetic field in the induced magnetosphere is believed to be dominated by the draped field. The direction of such draped field is theoretically expected to align with the y-z direction of the interplanetary magnetic field. However, observations show the opposite direction of magnetic field in the induced magnetospheres from the interplanetary magnetic field direction. Using joint observations from Tianwen-1 and MAVEN, we obtain the averaged magnetic field map of the Martian induced magnetosphere in the accurate MSE coordinate system and calculated its standard deviation. The standard deviation confirms that the averaged magnetic field distribution is consistent with the steady state assumption. The magnetic field map illustrates a clockwise rotation of the averaged magnetic field in the y-z plane, occurring in both the dayside and nightside in the Martian induced magnetosphere. According to the magnetic induction equation, this clockwise rotation of the magnetic field occurs when a difference in the speed of plasma flow exists within the magnetosphere. It should be noted that the induced magnetospheres of the other non-magnetized planets exhibit similar qualitative properties to that of Mars, suggesting that they share comparable magnetic field characteristics. Observations of the response process of induced magnetosphere to external magnetic field are significant for understanding global dynamical processes in non-magnetized planets, and yet such observations are quite scarce. Using simultaneous observations from Tianwen-1 and Mars Atmosphere and Volatile EvolutioN (MAVEN), we report for the first time the dynamic response of the Martian induced magnetosphere to the rotation of interplanetary magnetic field from the Sun. The magnetic field in the Martian induced magnetosphere deflected as the interplanetary magnetic field rotated suddenly, and eventually stabilized (< 3.5 minutes). The convective electric field rotated in response to the interplanetary magnetic field rotation, and the pick-up oxygen ion plume emerged in minutes (< 3 minutes). These quite short recovery timescales indicate that the induced magnetosphere is a rapidly dynamic system, and is highly sensitive to external magnetic field. It cautions us that change of interplanetary magnetic field should be considered as one of the general types of space weather on Mars, and it is essential of monitoring and short-term forecasting of interplanetary magnetic field upstream of Mars.
Understanding the Heterogeneity and Anisotropy of Permeability in Carbonate Rocks Within a Fault Network
Authors: Akbariforouz Mohammadreza , Zhao Qi , Zheng Chunmiao
Published: March 2024

The complexity of fault zone structure and faulting mechanisms significantly impact the permeability of fault zone rocks. Various factors, including the type and porosity of the host rock, the fault’s geometry, differential strain, the history of deformation, and the tectonic setting, can cause permeability to exhibit wide fluctuations. However, research into the permeability of complex fault zones is constrained by the scarcity of in situ measurements. Utilizing analytical relationships, laboratory tests, outcrop measurements, or numerical modeling often yields biased results, as they may not accurately represent real-world conditions. Moreover, the effects of fault branching and interconnections have not been thoroughly explored. This study compares the permeability of faulted carbonate rocks using a comprehensive database of in situ permeability tests. We investigate how a network of seven faults influenced permeability variations at different locations and depths by examining surface and subsurface data, including information from excavated tunnels. Our findings reveal that factors such as fault dips, length, fault structure, and rock characteristics can create diverse impacts on permeability. We observe permeability values in fault damage zones one to five orders of magnitude higher than those in the host rocks. The thickness and condition of damage zones shed light on the range of fault zone permeability. Furthermore, we find that faulted rocks with higher porosity and lower mechanical strength exhibit more substantial alterations in permeability. This study provides valuable insights into the behavior of faulted carbonate rocks.
EUROHAB II: A Lunar Secondary Habitat platform for Space Analogue Mission
Authors: Singh Nisheet , Weiss Peter , Pouget Thibaut , Makthoum Mohamed
Published: March 2024

The ARTEMIS program was launched by NASA to send astronauts back to the Moon to establish a permanent presence. The ARTEMIS missions will pave the way for the next big step—the launch of the first humans to Mars—by utilizing the Moon.Unlike the Apollo missions, ARTEMIS missions are targeting the Lunar South Pole because of the Points of Interest such as the presence of water ice in the Permanently Shadowed Regions (PSR) in the craters, Peaks of Eternal Light (PEL) with high solar illumination, and constant contact with Earth.  On the lunar surface, a crew can travel two kilometres on foot, ten kilometres in an unpressurised rover, and twelve kilometres in a pressurised rover from the Human Landing System (HLS). Security reasons dictate these distances, enabling the crew to return to the HLS in an emergency. There is a clear gap between the points of interest and the safe landing spots identified in the frame of the ARTEMIS program.A Secondary Habitat such as EUROHAB will close the gap between the safe landing spots and the points of interest. EUROHAB is an inflatable, deployable habitat delivered as a payload on a medium-size robotic lander (such as the ESA Argonaut/EL3 or the NYX of The Exploration Company) to the surface of the Moon. If placed strategically on the Lunar surface, EUROHAB not only will act as an outpost or a base camp to extend the range of exploration but also as a safe haven in case of off-nominal scenarios where the crew can take refuge. Additionally, EUROHAB can also serve as a teleoperated science station with experiments running autonomously, a storage place that can be utilized by the next missions, and assist Lunar surface assets like a rover for lunar night survival. A full-scale prototype was developed based on a CNES study (named “LISE”) to develop a lunar habitat that can be brought to the Lunar surface by ESA's Argonaut Lander to serve as a secondary habitat for the Artemis missions. EUROHAB II scale one prototype was exhibited at Assemble Nationale, Paris in June 2023. This platform will serve to test subsystems like the Life Support System, Energy Management, Robotics or Communication. EUROHAB could be a French or European contribution to Artemis which also makes use of other ESA elements of lunar logistics like the communication and navigation network MOONLIGHT.EUROHAB II will be setup in Tignes, France for a five-day simulation mission from 22nd January 2024 to 26th January 2024 to test several aspects related to the mission simulation and system testing. The objective of this mission is to test the system in a harsher analogue environment (high altitude and polar conditions). Also, the team expects to test different internal configurations of such Secondary Habitat. The paper will detail the results of the analogue simulation activity.
Exploring the controls of catchment similarity for the transfer of rainfall-runoff model parameters: a comparative study in different large-sample datasets around the globe
Authors: Neri Mattia , Toth Elena
Published: March 2024

The question of what makes two catchments hydrologically similar is of fundamental importance for the understanding of catchment hydrology and for transferring hydrological information from gauged to ungauged catchments. In the regionalisation of rainfall-runoff model parameters, the definition of a similarity measure for identifying the donors basins as a function of catchment characteristics is an essential step for the most consolidated techniques. As demonstrated by a very large number of studies in the literature, conducted all around the world, the main controls of catchment similarity may change subtsantially across different hydroclimatic regions.The recent availability of large-sample catchment dataset for rainfall-runoff studies in different hydroclimatic regions across the globe allows scientists to conduct comparative experiments for enhancing our knowledge about the factors that shape hydrological processes, including catchment similarity and regionalisation.The aim of this study is to test how hydroclimatic characteristics in different regions of the world influence the main factors that control catchment similarity when regionalising rainfall-runoff model parameters, using a homogenised modeling protocol.Two conceptually different bucket-type rainfall-runoff models are calibrated on more CAMELS-type large samples of catchments all around the world, characterised by different hydroclimates and data availability (i.e. streamgauge density). For each regional sample and for each model, one of the most consolidated parameter regionalisation approaches, based on the choice of a set of “most similar” donor catchments and on the transfer of the entire sets of model parameters from the donors to the target catchment, is applied in jack-knife cross-validation. Naturally, in such approach the choice of the donors (and therefore the regionalised model parameters) strictly depends on the catchment descriptors used to define the similarity measure between target and gauged basins.Assuming that the higher is the similarity of the donors to the target catchment, the better is the model performance, the idea of the work is to assess which catchment features better represent similarity for the transfer of model parameters in each of the regional samples. In particular, it is interesting to analyse if and how such features change across different hydroclimates. In order to reach such goal, the regionalisation technique is implemented by including different typologies and combinations of climatic and/or morphological characteristics when defining similarity, therefore obtaining different donors and different regionalised model performances. The findings achieved in the different large samples are compared, mainly focusing on how the set of basin descriptors bringing to the best model performances varies across the different hydroclimatic regions.
The Weddell Sea atmospheric CO2 uptake: An overview of its seasonal cycle and relationship to sea ice
Authors: Droste Elise , Hoppema Mario , Bakker Dorothee , Huhn Oliver , Landschützer Peter
Published: March 2024

The Weddell Sea has previously been estimated to be a net atmospheric CO2 sink, transporting anthropogenic CO2 to deeper parts of the ocean. However, a paucity of spatial and temporal observational data coverage hinders a complete understanding of its (seasonal and interannual) variability, how it is affected by seasonal sea ice cover, and how it may change with rapidly changing Antarctic sea ice regimes. We provide a status overview of all available partial pressure CO2 (pCO2) observations and estimates in the Weddell Sea, including SOCAT, GLODAP, and SOCCOM float datasets. We identify a particular lack of data on the continental shelves. Floats fill the wintertime-gap by obtaining year-round data, but are restricted to the open ocean and water depths of at least 2000 m. The collated dataset illustrates a seasonal cycle for the Weddell Sea, in which the summertime CO2 uptake can be strong with a mean of -1.2 mol m2 yr-1, but extremely variable (± 2.2 mol m2 yr-1). Some of the summertime CO2 uptake is compensated by wintertime CO2 outgassing, particularly in the northern Weddell Sea where sea ice cover is lowest and wind speeds are high. We use additional reanalysis and observational data-based products to perform a further analysis of differences between subregions within the Weddell Sea. Results show that most regions have a strong seasonal cycle in the sea-air CO2 gradient, with mean amplitudes ranging between 27 µatm (Northern Weddell Sea) and 100 µatm (eastern Peninsula shelf regions). However, wintertime outgassing is largely restricted by sea ice cover in all regions. The central Weddell Sea seems to be a particularly important region for net CO2 uptake, which is partly explained by the timing of wintertime sea ice advance before the surface pCO2 oversaturates with respect to atmospheric CO2. These results imply that the timing of sea ice advance or retreat can have high impact on the net CO2 uptake of the Weddell Sea.
Decadal-scale influence of the Kuroshio and Oyashio extension fronts on atmospheric circulation and storm track
Authors: Zhou Guidi , Li Xiang , Cheng Xuhua
Published: March 2024

Recent findings showed that midlatitude oceanic fronts in the Kuroshio-Oyashio Extension (KOE) region may significantly influence the overlying atmosphere on the interannual timescale. However, the exact mechanism and the combined effects of both the Kuroshio Extension Front (KEF) and the Oyashio Extension Front (OEF) are still largely unknown. Here we use front-resolving ERA5 reanalysis data to investigate the characteristics and mechanisms of the atmospheric response to interannual fluctuations of the KEF and OEF latitudinal position in a consistent way. It is found that the when the fronts meridionally migrate, response of the marine atmospheric boundary layer is remarkable. The response is mostly equivalent barotropic, with upper atmosphere intensification and sign reversal of temperature anomalies. Significant response of the storm track is also found. Diagnosis showed that eddy-mean flow feedback mediated by the storm track is responsible for the large-scale circulation changes, by means of both eddy heat flux and eddy vorticity flux. The spatial pattern of the KEF influence is a zonal dipole and the OEF is a monopole. The northward excursion of the KEF and OEF generally forces atmospheric responses with reverse sign. However, as the KEF and OEF moves in opposite directions with a lag time of 2.5 years, their atmospheric impacts sustains each other.
Effect of soil-plant interactions on nutrient availability and supply in a tropical Andean ecosystem 
Authors: Molina Armando , Vanacker Veerle , Chadwick Oliver , Zhiminaicela Santiago , Corre Marife , Veldkamp Edzo
Published: March 2024

Plants play a key role in absorbing nutrients and water through their roots, and modulate the biogeochemical cycles of terrestrial ecosystems. Nutrient uptake mechanisms of water and nutrient by plants depend on climatic and edaphic conditions, as well as of their root systems. Soil solution is the medium in which abiotic and biotic processes exchange nutrients, and nutrient concentrations vary with the abundance of reactive minerals and fluid residence times. High-altitude grassland ecosystems of the tropical Andes are particularly interesting to study the relationship between vegetation communities, soil hydrology and mineral nutrient availability. In páramo ecosystems, forest, tussock grasses and cushion plants co-occur across the landscape. In the nutrient-depleted nonallophanic Andosols, the plant rooting depth varies with drainage and soil moisture conditions. Vegetation composition is a relevant indicator of rock-derived nutrient availability in soil solutions. Significant variations in the soil solute chemistry revealed patterns in plant available nutrients that were not mimicking the distribution of total rock-derived nutrients nor the exchangeable nutrient pool, but clearly resulted from strong biocycling of cations and removal of nutrients from the soil by plant uptake or deep leaching. Our findings highlight the importance of vegetation communities, soil hydrological condition, and the bioavailability of mineral nutrients to trigger rapid and complex changes in the biogeochemistry of soil waters. Moreover, the findings have important implications for future management of Andean ecosystems where vegetation type distributions are dynamically changing as a result of warming temperatures and anthropogenic disturbances. Such alterations may not only lead to changes in soil hydrology and solute geochemistry but also to complex changes in weathering rates and solute export downstream with effects on nutrient availability in Andean rivers and high-mountain lakes.
Aerosol vertical profile retrievals using passive radiometric measurements
Authors: Lind Elena , Herreras-Giralda Marcos , Momoi Masahiro , Eck Thomas , Sinyuk Alexander , Dubovik Oleg
Published: March 2024

Aerosol vertical profiles in the lowest 1 km of the atmosphere are not very well studied due to technology limitations (e.g. LIDARs) and air space restrictions (e.g. manned and unmanned aircrafts). This study investigates sensitivity of the radiance measurements to the aerosol profiles from the standard columnar almucantar and direct sun measurements combined with low elevation sky scanning (from the horizon to zenith direction). Sensitivity studies are conducted for the sun-sky radiometer filter bands deployed within AERONET. AErosol RObotic NETwork (AERONET) is a network of sun-sky-moon photometers that measure solar radiation at 9 wavelength bands (centered at 340, 380, 440, 500, 675, 870, 937, 1020, 1640 nm, 2-10 nm except 25 nm for 1640 nm FWHM filter transmission). The main AERONET products are columnar aerosol optical depth, Angstrom exponent (from direct sun measurements), single scattering albedo and size distribution (from Almucantar and hybrid scans). The additional products investigated in this study are vertical volume density and aerosol extinction coefficient profiles. GRASP (with the plane parallel radiative transfer model) is initially used to simulate scattered sky radiances and conduct aerosol profile inversions. Several aerosol models and loadings are investigating as well as aerosol volume density profiles.
Development of ship navigation risk indicator in sea ice-infested water
Authors: Zhang Xinfang
Published: March 2024

There's increasing transpolar shipping in both the Arctic and Antarctic as a result of the reduction of sea ice and the desire from social economics.  Sea ice is a hazard for shipping in ice-infested water, Ship navigability in ice-covered sea depends on sea ice concentration, ice thickness, fraction of pressure ridges, and multi-year ice as well as ice speed and compression, it also depends on the vessel ice class. IMO introduced Risk Index Outcome(RIO) to provide guidelines for safe navigation, calculation of RIO requires accurate sea ice information including sea ice concentration and thickness. We developed a method similar to RIO to calculate navigation risk indicators using forecasting models including ECMWF S2S data, Copernicus data, and DMI data. Other than conventional sea ice parameters sea ice concentration and sea ice thickness, ice salinity, and ice age are also taken into account in risk indicator calculation. We select the time March 2019 -Oct 2020 and adopt the initial condition of the model forecast for sea ice to demonstrate the capabilities of seasonal forecasting of this navigation risk indicator in different models. In future, the calculation method will be implemented within the ClimateDT environment.
A Geodynamically Consistent Approach to Residual Topography and Geoid Anomalies on the Convecting Mantle: Importance of Global Crustal Models 
Authors: Kamali Lima Shayan , Forte Alessandro M. , Greff Marianne
Published: March 2024

While the isostatic compensation of crustal thickness and density heterogeneity provides the dominant contribution to Earth’s observed topography, there nonetheless remains a substantial difference (the ‘residual topography’) between these two fields. This difference is a consequence of dynamic processes occurring within the mantle, most notably due to time-dependent vertical surface stresses driven by mantle convection. Mantle convection dynamics also produce differences between the observed geoid and the isostatic geoid generated by crustal heterogeneity: the ‘residual geoid’. The joint consideration of both residual geoid and topography anomalies provides unique and fundamental global constraints on the amplitude and spatial distribution of density anomalies in the convecting mantle.Despite the crucial role of isostasy in determining residual geoid and residual topography, accurate constraints depend heavily on the quality of the isostasy calculations. The classical theory of isostasy relies on a 1st-order treatment of hydrostatic equilibrium, which is not sufficiently accurate for the calculation of isostatic geoid anomalies on a compressible, self-gravitating mantle. Consequently, we present a geodynamically consistent approach that is based on the surface loading response (via dynamic kernels) calculated with a viscous flow model that incorporates a fully compressible mantle and core (given by the PREM reference model) with self-gravitation.Another critical issue that remains outstanding is the accuracy inherent in global crustal heterogeneity models. Here we show that the differences between the residual geoid and topography fields predicted using CRUST1.0 (Laske et al. 2012) and the most recent ECM1 (Mooney et al. 2023) crustal heterogeneity models are substantial. We discuss the importance and implications of these differences in the context of determining the most accurate constraints on density anomalies in the convecting mantle.
Building hierarchical use classification based on multiple data sources with a multi-label multimodal transformer network
Authors: Zhou Wen , Persello Claudio , Stein Alfred
Published: March 2024

Effective urban planning, city digital twins, and informed policy formulation rely heavily on precise building use information. While existing research often focuses on broad categories of building use, there is a noticeable gap in the classification of buildings’ detailed use. This study addresses this gap by concurrently extracting both broad and detailed hierarchical information regarding building use. Our approach involves leveraging multiple data sources, including high spatial resolution remote sensing images (RS), digital surface models (DSM), street view images (SVI), and textual information from point of interest (POI) data. Given the complexity of mixed-use buildings, where different functions coexist, we treat building hierarchical use classification as a multi-label task, determining the presence of specific categories within a building. To maximize the utility of features across diverse modalities and their interrelationships, we introduce a novel multi-label multimodal Transformer-based feature fusion network. This network can simultaneously predict four broad categories and thirteen detailed categories, representing the first instance of utilizing these four modalities for building use classification. Experimental results demonstrate the effectiveness of our model, achieving a weighted average F1 score (WAF) of 91% for broad categories, 77% for detailed categories, and 84% for hierarchical categories. The macro average F1 scores (MAF) are 81%, 48%, and 56%, respectively. Ablation experiments highlight RS data as the cornerstone for hierarchical building use classification. DSM and POI provide slight supplementary information, while SVI data may introduce more noise than effective information. Our analysis of hierarchy consistency, supplementary, and exclusiveness between broad and detailed categories shows our model can effectively learn these relations. We compared two ways to obtain broad categories: classifying them directly and scaling up detailed categories, associating them with their broad counterparts. Experiments show that the WAF and MAF of the former are 3.8% and 6% higher than the latter. Notably, our research visualizes attention models for different modalities, revealing the synergy among them. Despite the model’s emphasis on SVI and POI data, the critical role of RS and DSM in building hierarchical use classification is underscored. By considering hierarchical use categories and accommodating mixed-use scenarios, our method provides more accurate and comprehensive insights into land use patterns.
Triggering rainfall for torrent floods and debris flows in Austria and assessment of climate change impact
Authors: Kaitna Roland , Becsi Benedikt , Schlögl Matthias , Schöffl Tobias , Hrachowitz Markus , Rieder Harald , Formayer Herbert
Published: March 2024

Debris flows represent a severe hazard in Alpine regions. The initiation of debris flows is connected to several hydro-meteorological and geomorphological factors. For operational early warning and assessment of climate change impact, knowledge about critical rainfall conditions is needed. For several regions of the European Alps intensity-duration (I-D) thresholds for debris flows have been derived in recent years. In this study we provide triggering rainfall conditions of high temporal and spatial resolution for > 3700 documented torrent processes including debris flows that occurred in Austria between 2003 and 2022. Additionally, we estimate the change in their probability of occurrence in a future climate, based on an ensemble of bias corrected and localized EURO-CORDEX simulations. We find slightly steeper I-D curves for debris flows than for torrent floods and no clear trend indicating substantial influence of antecedent rainfall on the triggering rainfall. For all process types, it is shown that both the probability of occurrence and the areas affected by triggering precipitation events increase substantially in the future, with clear dependences on the emission scenarios (RCPs). The results of this study provide a basis for improved event forecasting in a changing climate. 
Same same but different: the scientific challenges when re-using the subsurface for sustainable energy developments
Authors: Hangx Suzanne
Published: March 2024

Though global energy needs continue to grow, fossil fuels, and their associated CO2 emissions, are increasingly being opposed as our main source of energy. Instead, to achieve net zero greenhouse gas emissions goals, we are currently transitioning to more sustainable sources of energy, such as solar and wind power and geothermal energy, coupled with storage of waste, such as CO2. However, these new technologies come with their own challenges, as they continue to rely on (re-)use of the subsurface landscape. The intermittency of solar and wind power will require storage of renewably generated electricity. Hydrogen fuel has been marked as a potential energy carrier, enabling us to store large quantities of energy for prolonged periods of time, such as required to supply large industries or communities during winter months. To store this hydrogen fuel, the subsurface offers the largest storage space available, such as in (offshore) depleted hydrocarbon fields, but reproduction of the stored fluid is crucial. Geothermal energy production will require the extraction of hot fluids from depth and will often be performed in populated areas, close to the consumers, meaning that phenomena such as surface subsidence and induced seismicity are highly undesirable. The safe storage of CO2 for thousands of years also entails fluid injection, but containment is of vital importance to keep the CO2 out of our atmosphere. So though we have a vast history of exploitation of the subsurface through the oil and gas industry, which we can and should build upon, these new sustainable energy developments also pose their own, new challenges. While fluid production changes the physical equilibrium of the system, these new uses will also impact the chemical equilibrium through the injection of new fluids. Furthermore, containment and safety play an even bigger role than before to ensure the longevity of these new subsurface operations. In this contribution, I will outline what the challenges are that we are facing and how geoscientists can contribute to solving these challenges, across all areas from rock physics, geochemistry and hydrology, to sedimentology, structural geology and policy.
Metrics that Matter: Calibration Choices and Their Impact on Signature Representation in Conceptual Hydrological Models
Authors: Wagener Peter , Spieler Diana , Schütze Niels
Published: March 2024

Hydrologists are generally aware that the choice of calibration metric will affect how their model reproduces catchment runoff. However, scientific literature mainly provides a theoretical or case study specific discussion of the topic and no general guidelines. This study thus aims to develop a broader picture by evaluating the influence of 8 different objective functions on the representation of 15 hydrologic signatures for 45 lumped conceptual models in 10 climatically diverse catchments.The 10 selected catchments are a subset of the CARAVAN dataset (Kratzert et al. [2023]) chosen by using a k-means clustering algorithm based on climate indices (Willmott and Feddema [1992]). The 45 models are taken from the MARRMoT toolbox (Knoben et al. [2019], Trotter et al. [2022]) and only models performing over a specified benchmark are used for the analysis. The signatures that will be analysed represent different processes and aspects of the hydrological regime and the following 8 calibration metrics are investigated: KGE, NSE, log KGE, log NSE, NP-KGE (Pool et al. [2018], Split KGE (Fowler et al. [2018], SHE (Kiraz et al. [2023], DE (Schwemmle et al. [2021]).Preliminary results show that the ability to reproduce specific signatures is clearly influenced by the chosen metric and therefore this choice should always be based on the specific goal of the prospective modelling study. Each metric has specific strengths and weaknesses that may be used to make a decision. However, the results vary based on climate conditions, the applied model structure and the investigated signature. It is therefore difficult to disentangle all interdependencies and develop more general guidelines with the limited catchment set used in this study. We speculate that very dominant processes shaping the general runoff generation in a catchment (such as snow melt) reduces the impact of the choice of calibration metric, and that more complex models typically are more consistent in process representation.References:Fowler et al. (2018): doi: 10.1029/2017WR022466Gupta et al. (2009): doi: 10.1016/j.jhydrol.2009.08.003Kiraz et al. (2023): doi: 10.1029/2023WR035321Knoben et al. (2019): doi: 10.5194/gmd-12-2463-2019Kratzert et al. (2023): doi: 10.1038/s41597-023-01975-wNash and Sutcliffe (1970): doi: 10.1016/0022-1694(70)90255-6Pool et al. (2018): doi: 10.1080/02626667.2018.1552002Schwemmle et al. (2021): doi: 10.5194/hess-25-2187-2021Trotter et al. (2022): doi: 10.5194/gmd-15-6359-2022Willmott and Feddema (1992): doi: 10.1111/j.0033-0124.1992.00084.xDisclaimer: The first author conducted the presented research at TUD, now a PhD student at UofC
Hybrid neural differential equation models for atmospheric dynamics
Authors: Gelbrecht Maximilian , Boers Niklas
Published: March 2024

Combining process-based models in Earth system science with data-driven machine learning methods holds tremendous promise. Can we harness the best of both approaches? In our study, we integrate components of atmospheric models into artificial neural networks (ANN). The resulting hybrid atmospheric model can learn atmospheric dynamics from short trajectories while ensuring robust generalization and stability. We achieve this using the neural differential equations framework, combining ANNs with a differentiable, GPU-enabled version of the well-studied Marshall Molteni Quasigeostrophic Model (QG3). Similar to the approach of many atmospheric models, part of the model is computed in the spherical harmonics domain, and other parts in the grid domain. In our model, ANNs are used as parametrizations in both domains, and form together with the components of the QG3 model the right-hand side of our hybrid model. We showcase the capabilities of our model by demonstrating how it generalizes from the QG3 model to the significantly more complex primitive equation model of SpeedyWeather.jl. 
Burning poop: carbon dynamics in herbivore dung during southern-African savanna fires
Authors: Sánchez-García Carmen , Santín Cristina , Strydom Tercia , Doerr Stefan
Published: March 2024

Herbivores play a vital role in the functioning of savanna ecosystems. They ingest plants, modifying the vegetation cover, and disperse nutrients across the landscape in the form of dung. Fire in savanna is also a key nutrient recycling pathway, making elements readily available through the resultant ash and smoke. Wildfire ash, known for its susceptibility to be transported by wind and water, plays a key role in redistributing pyrogenic organic matter and nutrients across the landscape. However, our level of understanding of ash characteristics from burnt dung is very low. In addition, and due to its high carbon content, dung also adds to the wildland fuels for fires, alongside vegetation. Given that savannas are the dominant source of global Cemissions from fires, assessing the role of burnt dung in C dynamics is, therefore, also crucial for more accurate estimations of the overall C released during savanna fires.We quantified C losses from dung combustion during fire in four savanna sites burnt by experimental fires in Kruger National Park (South Africa). We also analysed chemical properties, including major nutrients and metals, of dung and dung-derived ash. The studied dung came from large herbivores (zebra, elephant, giraffe, buffalo and wildebeest). The concentration of carbon and nitrogen in burnt dung was significantly lower than unburnt dung (carbon: 41 and 4.1%, nitrogen: 1.1 and 0.3% in unburnt and burnt dung, respectively). The carbon released from dung burning accounted for up to 6% of the carbon released from vegetation burning, emphasizing the substantial role of dung in carbon emissions during savanna fires. Our results also highlight burnt dung as a hotspot for minerals and nutrients with chemical characteristics different to those found in vegetation ash (e.g., phosphorus: 9,195 and 6,158 mg kg-1, copper: 55.8 and 28.1 mg kg-1 in dung-derived and vegetation ash respectively). This is likely to affect local soil physical and chemical properties and hence enhance ecosystem diversity.
Coupled evolution of rivers and floodplains
Authors: Nicholas Andrew , Aalto Rolf , Ashworth Phil , Best Jim , Bruckner Muriel , Gasparotto Andrea , Paes de Almeida Renato
Published: March 2024

River-floodplains are coupled systems in which the conveyance and cycling of sediment over centuries to millennia set the morphological and sedimentological boundary conditions that control fluvial processes over shorter time periods (e.g., years to decades). Although this is well known, understanding how such processes are coupled over short and long timescales remains a significant challenge. Moreover, fluvial geomorphology as a discipline has, arguably, focused more on the study of within-channel processes and dynamics, with less attention given to how river-floodplain interactions and feedbacks control the functioning of the wider river corridor (i.e., channel-belt). Growing concern over the potential impacts of 21st century environmental change (e.g., on river morphology, flood conveyance and floodplain ecosystems) highlights a pressing need to address this knowledge gap.This study applies a physically-based morphodynamic model to investigate the coupled evolution of channel-floodplain systems. The model solves the shallow water equations for in-channel and overbank flows, together with equations representing fine and coarse sediment transport, channel migration and floodplain development. Simulations are run over time periods sufficient for the floodplain to be reworked (and hence reconstructed) by the model. Simulation results provide new insights into: (i) the relative importance of river gradient, sediment flux and bank erodibility as controls on channel migration rates; (ii) the factors that determine the mechanisms and frequency of channel cutoffs; (iii) the degree to which floodplain dynamics (e.g., floodplain reworking and construction) control both floodplain topography and river pattern; (iv) the relative importance of bedload versus suspended load in determining overall fluvial system behaviour; and (v) the challenges involved in simulating these effects using numerical models.
Data quality of large dense seismic networks – lessons learnt from AlpArray and application to AdriaArray
Authors: Kolínský Petr , Vecsey Luděk , Stampa Johannes , Eckel Felix , Belinić Topić Tena , Working Group the AlpArray , Seismology Group the AdriaArray
Published: March 2024

Large dense seismic networks popping up around the world in the last two decades enable studying the wave propagation and structure of the Earth with unprecedented details. Hundreds of broadband seismic stations spaced by tens of kilometers produce large amounts of data, which is usually processed by automatic routines. The data is no longer supervised by seismologists on a detailed level of every record as thousands of hours of data are handled at once. Ensuring the quality of data and accompanying metadata is nowadays a discipline by and of itself. Besides the classical techniques, which investigate the properties of data at a single station, large dense seismic networks allow for a multi-station approach to review the quality of the data. The diagnostic tools of multi-station methods are based on the detection of outlying stations/records among many others. Properties of the wavefield of wavelengths longer than the station spacing vary smoothly and hence comparing the measurement at neighboring stations allows for identifying anomalous behaviors. These methods work under the assumption that most of the (meta-) data is correct, and therefore a small number of outliers can be detected. Thus, not only do large dense seismic networks contribute to research, which is their primary goal, but thanks to the design of these networks, data quality can also be tested more precisely than before. We review both types of techniques, showing examples of the AlpArray experiment (2015 - 2022), and discussing the development of the approaches over the years to what is nowadays applied to the AdriaArray Seismic Network. AdriaArray experiment started in 2022 and encompasses now around 1000 permanent as well as over 430 temporary broadband stations. We show how the availability and retrievability of the data are checked, how amplitude and phase information from the ambient and deterministic wavefields are used to assess the correctness of metadata and how we represent the results of these tests in maps and tables. The purpose of these tests is aimed in both directions: towards the users, so that they are aware of potential issues, as well as towards the station operators so that they can be notified and asked to fix the detected problems.
Correlating tomography structure parameters with physical soil functions in representative sites in Schleswig-Holstein, Germany
Authors: Roosch Svenja , Ormeno Jocelyn , Uteau Daniel , Fleige Heiner , Mordhorst Anneka , Rostek Jens , Wiermann Conrad , Müller Gerrit , Peth Stephan
Published: March 2024

Soil structure influences important soil functions like hydraulic conductivity and air permeability, which in turn influence plant growth. The physical structure of soils is thus, besides chemical and biological parameters, one major component of soil fertility. Unfortunately, this physical fertility is often impaired by agricultural practices.To study the structural status and the relationships between structural and functional parameters, 45 representative arable sites in Schleswig-Holstein, Germany, were sampled at three depths in top- and subsoil. Soil structure was described quantitatively using X-ray computed tomography of soil cores (continuity and size distribution of macropores). Measured soil functions included saturated hydraulic conductivity, air permeability, air capacity, and pore size distribution (via water retention curves).The results not only help elucidate relations between structural and functional soil parameters. They also give a detailed and comprehensive insight into the structural state and their relation to soil physical functions of typical arable sites across Schleswig-Holstein that has not existed before.
AMOC weakening and its association with increased dynamic sea level in recent decades 
Authors: Eresanya Emmanuel , McCarthy Gerard , MecKing Jennifer , Yinghui He , Osinowo Adekunle
Published: March 2024

The Atlantic Meridional Overturning Circulation (AMOC) is a crucial mechanism of poleward heat transport in the ocean and climate system. It modulates the redistribution of heat and carbon in the northern hemisphere. The state of AMOC in recent decades has revealed a slowdown compared to the industrial era. Its state is linked to a number of physical factors, including sea level. Along the eastern seaboard of North America, on long timescales, the imprint of the AMOC is projected onto sea level patterns. The relationship between AMOC weakening and sea level is not clearly understood. This study investigates the state of the AMOC in recent decades and its link to the regional sea level using CMIP6 and RAPID datasets.One of the most critical questions in ocean science is whether climate models and observations of the state of the AMOC in recent decades are consistent. If these datasets show significant differences, it could lead to a bias in our projected long-term climate knowledge. This study shows the potential of sea level data to inform the evolution of the AMOC to constrain and improve future projections.
Extreme weather threatening vineyards of North-East Italy: multi-temporal satellite analysis in Google Earth Engine 
Authors: Baldan Vincenzo , Straffelini Eugenio , D'Agostino Vincenzo , Tarolli Paolo
Published: March 2024

The northern-east part of Italy is an important wine production area, which exports high-quality wine worldwide. The territory boasts of areas that are under the protection of FAO and UNESCO, thanks to the unique relationship between landscape and agriculture. In the last two decades, extreme weather events created criticalities, especially in steep slope territories.Future climate trends could influence the frequency of heatwaves, drought and intense rainfalls, impacting on vineyards. Therefore, identifying trends helps to understand the risks to which vineyards are subjected.The purpose of this study is to identify extreme weather trends in the area located in Veneto and Friuli-Venezia Giulia and discover areas that are more affected by increasing and decreasing trends. The workflow started with analyzing historical climate data in different datasets in Google Earth Engine. We implemented the Land Surface Temperature dataset of the Modis satellite for surface temperatures and the CHIRPS Daily dataset for historical precipitation data. Additionally, for 2-meter temperatures and cumulative rainfall, we considered weather station data.Based on the initial findings, the summer of 2022 reported strong heatwaves and drought. Certain areas showed an increase in surface temperature of more than +20%, compared to the mean summer temperature during the 2000-2010 period. For precipitations, otherwise, the central-east part of the region reported a negative anomaly of around -50 % compared to the summer average of the last 30 years.Future research activities will focus on intense rainfall and more about the frequency, duration and distribution of heatwaves and drought to detect future scenarios.The results of this research may inspire the development of sustainable initiatives focused on improving water management, aiming to reduce run-off during intense precipitations and enhancing water storage during drought seasons, as well as on supporting the insurance companies to provide tailored risk coverages against increasing climatic risks in vineyard farms.
Adapting to Heat Extremes with Unequal Access to Cooling: Evidence from India
Authors: Pavanello Filippo , Sue Wing Ian
Published: March 2024

As global temperatures rise, the unequal access to residential cooling technologies, especially air conditioning, poses a critical challenge for heat adaptation in developing countries. To mitigate this disparity, affordable alternatives like evaporative coolers have been proposed. However, the extent to which they provide protection against extreme heat is uncertain. This paper investigates the inequality in heat adaptation, examining the effectiveness of alternative cooling technologies in mitigating mortality impacts from extreme heat in India for the period 2014-2019. Our empirical results highlight a critical trade-off in heat adaptation. While we find that the expensive air-conditioning proves to be highly effective in reducing temperature-related mortality, its ownership and use remains low, predominantly limited to high-income cities. In contrast, many Indian households, including low-income ones, purchase and use cheaper evaporative coolers, which we estimate offer reduced protection against heat stress. Our analysis then reveals that heat adaptation technologies have collectively reduced heat-related deaths by 21%, generating an annual gross welfare gain of $32 billion. Notably, the wide prevalence of evaporative coolers contributes to two-thirds of these benefits. Yet, our counterfactual scenario demonstrates that air conditioners, if as widespread as evaporative coolers, could have prevented 47% of the heat-related deaths. We conclude showing that subsidising air-conditioning is a cost-effective way to reduce heat-related mortality in India.
Three-dimensional monitoring of Ionospheric storms using COSMIC-2 RO
Authors: Joshi Lalit Mohan
Published: March 2024

High-rate Radio Occultation (RO) measurement using the COSMIC-2 constellation has enabled the observation of the transient changes in the ionosphere's three-dimensional (3D) structure.  This capability enables studying the changes to the 3D ionospheric structure during a geomagnetic storm. So far, the ionospheric storms (positive/negative ionospheric storms) that follow space weather events, have mostly been studied globally using two-dimensional (2D) TEC maps generated using ground-based networks. Ground-based networks also limit the measurements to only over the landmass and islands. High-rate 3D observation from COSMIC-2 can overcome these limitations of the ground-based networks. Such measurements provide 3D ionospheric variations over a large region lying within +/- 400 geographic latitude, with a spatiotemporal resolution significant enough to provide new insights.  This paper presents a 3D perspective of the ionospheric impact of the November 04, 2021, geomagnetic storm. In the present study, electron density has been binned with latitude, longitude, altitude, and time resolution of 60, 300, 25 km, and 2 hours, respectively. It must be noted that the present study excludes electron density variation below 225 km altitude where RO retrievals are not considered reliable. Some of the key observed features of the ionospheric storm under consideration are: (a) Large enhancement in the ionospheric plasma density due to the enhanced ‘fountain effect’ in the main phase is most significant in the topside ionosphere with a maximum variation observed above 450 km, (b) the most significant enhancement in the topside ionospheric plasma density (positive storm effect) was seen during the midnight period, irrespective of the longitude under consideration, (c) enhancement in the electron density also indicated some longitudinal dependence, and (d) most significant impact of the ionospheric storm was observed over the latitudinal belt lying beyond the poleward boundary of the EIA crests.  These and several other interesting observations will be presented. Results will also be discussed in light of the current understanding of ionospheric storms.