bluuebunny/crossref_metadata_2025 huggingface dataset:
Advancing multi-(hazard)risk science: embracing complexity and cross-disciplinary collaborations
Authors: de Ruiter Marleen
Published: March 2024

Recent disasters have demonstrated the growing challenges faced by society as a result of multi-hazards and compound events. The impacts of such disasters differ significantly from those caused by single hazard disasters: often the impacts of a multi-hazard disaster exceed those of the sum of the impacts of the individual hazards. Recognizing this complexity, the scientific community and international organizations, such as the UNDRR, have been advocating for a more integrated approach in multi-(hazard)risk research. This requires bridging across individual hazard types, but also learning from methodological advances made in neighbouring research fields such as the compound events community.This talk aims to highlight recent advances in assessing the complexities of multi-(hazard)risk and discusses opportunities for further enhancing our modeling capabilities through multidisciplinary collaboration. A crucial challenge of modelling compound and multi-hazard risk, is that of the spatiotemporal dynamics of risk. This includes for example, an improved understanding of post-disaster recovery after multi-hazard disasters and the role of (changing) local contexts within which disasters take place such as the dynamics of socioeconomic vulnerability and the likelihood of post-disaster disease outbreaks. Embracing these challenges and opportunities can support more comprehensive and effective disaster risk management strategies in the future.
Simulation of historical ocean heat and salt content changes in the Atlantic basin in CMIP6 models
Authors: Sinha Bablu
Published: March 2024

The Atlantic Multidecadal variability (AMV) is a multivariate climate phenomenon with wide societal impacts in the North Atlantic region and beyond. In order to gain insight into the circulation dynamics controlling the AMV, we calculate Atlantic upper ocean heat and salt budgets at the basin and sub basin scale, focussing on multi-year to multidecadal timescales, for the upper ocean using output from a subset of CMIP6 models which have the same ocean component (the NEMO model) at nominal horizontal resolutions of 1 degree, ¼ degree and 1/12 degree and corresponding atmosphere-forced ocean-only models. We decompose the advection term into geostrophic and ageostrophic components and further use a Reynolds type decomposition to understand contributions from time-mean versus transient components of the flow. We use a novel decomposition of the large-area heat budget which highlights contributions due to spatial covariance between the large scale circulation and temperature/salinity gradients. Finally we relate the spatial pattern of the heat and salt advection to the meridional overturning (zonal) and horizontal gyre (azonal) components of the flow.
Quality Assurance in Conceptual Hydrologic Models: Developing functional validation tests for ensuring model quality and robustness
Authors: Bucher Florian , Hauffe Corina , Spieler Diana , Schuetze Niels
Published: March 2024

Currently, the quality assurance of conceptual hydrological models is primarily based on calibration and validation procedures, such as the validation tests proposed by Klemeš [1986]. These procedures provide insufficient testing of the underlying assumptions of a model structure and their correctness and credibility for specific purposes. While we assume the models we use are implemented physically correct, actual “crash tests” (Andréassian et al. [2009]) or quality assurance procedures do not exist.This study therefore focuses on the development of a standardized quality assurance procedure for conceptual hydrologic models. A so called functional test scheme is proposed that complements existing calibration and validation procedures. Hereby, expected and unexpected model setups and parameterizations are tested and the model response is evaluated. The applied functional approach involves self-generated time series with synthetic climate data and a synthetic catchment to systematically test individual processes and procedures. We developed a line of test series for the modular modelling framework RAVEN, where several iterative test runs with changing model setups and parameterizations have been conducted in order to gain further insights into the correctness and plausibility of the implemented approaches and equations. We developed an R package that enables the almost automated execution of the repetitive processes in the test application for the RAVEN-based models.Preliminary results revealed some minor and major problems of model functioning, sometimes related to simple reasons like unclear information in the model documentation. For example, showed the testing that the slope correction for different slope angles is not applied on manually entered PET data, while the documentation does not explicitly mention that slope angles are only affecting internally generated PET data. The conducted experiments prove the potential of readily developed functional tests and provide a basis for further developments in this regard.
Chaotic oceanic excitation of low-frequency polar motion variability
Authors: Börger Lara , Schindelegger Michael , Zhao Mengnan , Ponte Rui M. , Löcher Anno , Uebbing Bernd , Molines Jean-Marc , Penduff Thierry
Published: March 2024

Studies of Earth rotation variations generally assume that changes in non-tidal oceanic angular momentum (OAM) manifest the ocean's forced response to atmospheric pressure, wind, and heat and freshwater fluxes. However, on monthly and longer time scales, changes in OAM may also arise from chaotic intrinsic ocean variability, which has its origin in local non-linear (e.g., mesoscale) dynamics that can further map into mass fluctuations at basin scales. To examine whether or not such chaotic mass redistributions appreciably affect Earth’s polar motion, we compute monthly OAM anomalies from a 50-member ensemble of eddy-permitting global ocean/sea-ice simulations that sample intrinsic variability through a perturbation approach on model initial conditions. The resulting OAM (i.e., excitation) functions are compared both amongst each member and with Earth rotation data from 1995 to 2015. We find that intrinsic variability plays an important role in the excitation of the Chandler wobble, where it modulates the band-integrated excitation power due to forced OAM changes (2.5 mas² over 1995–2015, mas = milliarcseconds) by up to ±2 mas2. At interannual frequencies below the Chandler band, intrinsic signals (ensemble spread) account for 16–36% of the variability in the total equatorial oceanic excitation, with contributions being split almost equally between mass and motion terms. More than half of the variance in the mass term contribution is associated with one mode of intrinsic bottom pressure variability, which has opposite polarity between the Atlantic and the Southern Ocean and largest amplitudes around Drake Passage. Overall, chaotic oceanic excitation represents a factor to consider when interpreting low-frequency polar motion changes in terms of natural climate oscillations or core-mantle interactions.
Recent extreme heatwaves dwarfed by projected future events
Authors: Aglas-Leitner Philipp , Perkins-Kirkpatrick Sarah E. , Stone Daithi
Published: March 2024

In recent decades, unprecedented heatwaves have resulted in substantial impacts on human health and their environment. Previously, heatwave trend analysis has largely focused on trends across global warming thresholds or on specific regions. Furthermore, a variety of diverse heatwave parameters has been applied across separate studies, hampering direct comparison. What is more, there has been limited information on how future projections of individual events compare to recent extreme heatwaves.In our study, we define heatwaves as periods of at least three consecutive days where daily area-weighted mean temperature exceeds the regional 90th percentile. We utilize a comprehensive analysis framework based on four heatwave parameters and additional sub-parameters where appropriate: (1) heatwave duration in days, (2) heatwave severity, an intensity index enabling interpreting excess heat relative to the regional climatology, (3) cumulative heat, and (4) percentage of locally affected area. The latter is an area-based parameter providing information on the exceedance of local (grid cell level) climatology thresholds during the course of an individual heatwave in percent of the respective region’s overall area. For parameters (2) and (4) we, moreover, investigate two sub-parameters, namely median and maximum values. The first sub-parameter refers to the median value of the entire heatwave, whereas the second indicates that this maximum value is being reached for at least one day during the event. This analysis framework greatly increases the ability for individual heatwave-based and regional intercomparison, and, furthermore, explores both regional as well as local scale trends, thereby providing critical human-impact-oriented information. In addition to daily output from multi-model ensembles from models taking part in the Coupled Model Intercomparison Project Phase 5 and 6 and large initial-condition ensembles (CanESM5 and ACCESS-ESM1-5), we employ our framework to 14 regional events observed during the period of 2010-2021 and analyzed based on Berkeley Earth and ERA5. This provides crucial insights into how future heatwaves compare to recent events.Our results indicate that recently observed extreme heatwaves are dwarfed by projected 21st century events. Moreover, without even moderate reduction in greenhouse gas emissions the probability of reoccurrence or exceedance of these recent extreme reference values is significantly increasing, and they are still plausible under aggressive emission reduction scenarios.In conclusion, we can see that a lack of mitigation and adaptation measures could considerably increase human exposure to extreme heat. In particular as we found, depending on the scenario, significant increases in the percentage of locally affected area and the heatwave severity. Thus, these findings stress the necessity for substantial and ambitious mitigation efforts and for considering heatwaves well outside the lived experience for effective adaptation measures.
Long-Term Effects of Chabazite-Zeolite Tuff Amendments on Soil Quality in Arable and Perennial Cropping Systems
Authors: Ferretti Giacomo , Rosinger Christoph , Diaz-Pines Eugenio , Weninger Thomas , Sae-Tun Orracha , Faccini Barbara , Coltorti Massimo , Keiblinger Katharina
Published: March 2024

The use of natural zeolites to enhance soil properties has gained popularity, but there are limited long-term data on its effects. This study evaluates the Soil Quality Index (SQI) in three agricultural soil systems, 6-10 years post-application of chabazite zeolite. These soils had different management practices: intensive arable (cereals), intensive perennial (pear), and organic perennial (olive).In the arable system, chabazite was applied at rates of 5, 10, and 15 kg m-2, compared to unamended soil. Perennial systems were tested at 5 kg m-2. Analysis of 25 soil parameters related to soil health was conducted at each site, including soil physic-chemical properties (bulk density, pH, electrical conductivity, cation exchange capacity, C-N-P species), biological properties (microbial C-N-P, enzyme activity) and gaseous emissions (CO2, N2O and NH3 fluxes). Principal Component Analysis (PCA) was performed to determine the SQI using a linear scoring method.In the arable-cereal field, chabazite increased the SQI significantly from ~0.3 to ~0.6, but no clear dose effect was evident. The SQI also rose significantly in perennial fields thanks to the use of chabazite zeolites. Different indicators have been selected by the PCA at each site, suggesting that chabazite addition impacted soil quality differently in each cropping system.Overall, this research underscores chabazite zeolite potential to boost soil health, indicating a substantial enhancement in soil quality post-amendment.
A Gaussian anamorphosis model for asymmetrically distributed data
Authors: Varouchakis Emmanouil A , Pavlides Andreas , Hristopulos Dionissios T
Published: March 2024

Environmental mining and exploration present a challenge for spatial analysis due to small sample sizes and data clustering near mining sites. Additionally, the properties of the covariance function may vary across different mines within the same region, necessitating adaptable geostatistical techniques. A novel approach to analyzing mining data spatial dependence introduces the use of Gaussian Anamorphosis, employing the recently proposed Kernel Cumulative Density (KCDE) method. This technique is particularly effective for data sets that exhibit non-Gaussian distributions, such as the typically asymmetrically distributed natural resources data. Gaussian Anamorphosis through KCDE enables the transformation of skewed probability density functions (PDFs) into the normal distribution. KCDE converts the original data distribution into a continuous cumulative density function (CDF), smoothing out the discontinuities inherent in the traditional staircase CDF estimation approach. We extend our analysis by conducting Kriging interpolation on the transformed data. Since the transformed data distribution closely approximates the normal distribution, it is possible to use the Kriging variance to reliably estimate prediction intervals before the results are inversely transformed back to their original scale for practical interpretation.To explore the variability of our results, we implemented Monte Carlo simulations based on the transformed data. The simulations provide insights into the potential outcomes and their variabilities, which were then inversely transformed back to their original scale for practical interpretation.The findings of this study underscore the effectiveness of Gaussian Anamorphosis using KCDE transformation in dealing with non-Gaussian data distributions in geostatistical analyses. The approach enhances the reliability of spatial predictions and offers robust confidence intervals. Our research demonstrates the potential of combining advanced transformation techniques with geostatistical models to address complex spatial dependencies of natural resources data.The research project is implemented in the framework of H.F.R.I call “Basic research Financing (Horizontal support of all Sciences)” under the National Recovery and Resilience Plan “Greece 2.0” funded by the European Union – NextGenerationEU (H.F.R.I. Project Number: 16537).
Birth and death of a triple junction: The example of the Bay of Biscay
Authors: Mathey Roxane , Autin Julia , Manatschal Gianreto , Sauter Daniel , Schaming Marc , Somoza Losada Luis
Published: March 2024

The Bay of Biscay fossil triple junction separated three tectonic plates: North America, Europe and Iberia. It is defined by three pairs of conjugate margins: Armorican-North Iberian margins, the Goban Spur-Flemish Cap margins, and the West Iberia-Newfoundland margins. In this area, although it was proposed that steady-state spreading started in Aptian/Albian times and ceased around 80 Ma (Verhoef et al., 1986), the timing and opening directions during rifting and spreading remain uncertain. Indeed, oceanic magnetic isochrones are badly constrained. Moreover, exhumed mantle is exposed, so the Ocean-Continent Transition (OCT) of the three conjugate margins is difficult to localize (Boillot et al., 1988; Sibuet et al., 2007; Thinon, 1999; Tugend et al., 2015).  As a result, there is no consensus on kinematic reconstructions.This work, in the context of my PhD thesis, is part of the ANR project “FirstMove”. It is based on a multidisciplinary approach using geological data (wells, dives) and geophysical data (seismic reflection, magnetic, gravity and bathymetry data). Notably, we integrate the Breogham seismic reflection profiles which cross the fossil spreading ridge. We aim to redefine, map and date the different rift domains (necking, hyperextended, exhumed mantle and oceanic domains), in order to better constraint the evolution of the Bay of Biscay triple junction. Indeed, the Iberia plate kinematic is a keystone to understand the global kinematic of the whole Atlantic-Tethys system. Boillot, G., Winterer, E. L., & et al. (Eds.). (1988). Proceedings of the Ocean Drilling Program, 103 Scientific Results (Vol. 103). Ocean Drilling Program. https://doi.org/10.2973/odp.proc.sr.103.1988Sibuet, J., Srivastava, S., & Manatschal, G. (2007). Exhumed mantle‐forming transitional crust in the Newfoundland‐Iberia rift and associated magnetic anomalies. Journal of Geophysical Research: Solid Earth, 112(B6), 2005JB003856. https://doi.org/10.1029/2005JB003856Thinon, I. (1999). Structure profonde de la Marge Nord Gascogne et du Bassin Armoricain. Ifremer-IUEM, Brest, France.Tugend, J., Manatschal, G., Kusznir, N. J., & Masini, E. (2015). Characterizing and identifying structural domains at rifted continental margins: application to the Bay of Biscay margins and its Western Pyrenean fossil remnants. Geological Society, London, Special Publications, 413(1), 171–203. https://doi.org/10.1144/SP413.3Verhoef, J., Collette, B. J., Miles, P. R., Searle, R. C., Sibuet, J.-C., & Williams, C. A. (1986). Magnetic anomalies in the northeast Atlantic Ocean (35°-50° N). Marine Geophysical Researches, 8(1), 1–25. https://doi.org/10.1007/BF02424825
Resolving volcanic from anthropogenic metal input to modern lake Elmenteita, Kenya
Authors: Rosca Carolina , Kübler Simon , Muiruri Veronica , Junginger Annett
Published: March 2024

Lake Elmenteita located in the central Kenyan Rift System is a shallow (ca. 1 m deep on average), hyper-saline and alkaline playa lake of international bio-ecological importance, as emphasized by its classification as RAMSAR site (2005) and UNESCO world heritage site of “outstanding universal value” (2011). Unusually high rainfall and anthropogenic influence (deforestation, agriculture, sewage loading) are current drivers of changes in water level, composition and quality as well as the dramatic decline in riparian habitats. Identifying individual sources of both, elemental nutrients (P, N, Mg, Si, Zn) and potentially toxic elements (heavy metals, e.g., Cs, Mo, Pb, Sb, Cu) to the lake is imperative for ecosystem monitorization and development of biodiversity conservation strategies.Here, we present dissolved element concentrations in water samples collected in July 2022 from the 1) central, 2) northern (discharge of rivers Kariandusi and Mereroni), and 3) southern (dominated by tectonically modulated volcanic hot-springs) part of the lake, as well as from 4) river Mereroni and 5) an additional hot-spring in the eastern part of the catchment. Data was acquired in the field and at the laboratories of the Isotope Geochemistry Group, Tübingen University. Results show compositional differences between hot springs and riverine influx (e.g., Cs: 0.03 ng/g Mereroni river vs. 3.3 ng/g S-hot springs), and also between Mereroni river water and northern shore waters (e.g., Sb: 0.063 ng/g Mereroni river vs. 0.92 ng/g N-shore; Cu: 0.925 ng/g Mereroni river vs. 27.3 ng/g N-Shore). Accompanied by observed compositional heterogeneities within the lake itself, our findings suggest that several sources and processes govern the elemental influx and distribution. Using geochemical indices, we will propose elemental dispersion vectors, main sources, and in-lake processes with the aim to unfolding the impact of recent anthropogenic signals from volcano-tectonic elemental origins to the lake.
An online parameterization of biogenic VOC emission fluxes in the Integrated Forecasting System for atmospheric composition
Authors: Huijnen Vincent , Sindelarova Katerina , van der Worp Miró , Williams Jason , Rémy Samuel
Published: March 2024

 Biogenic volatile organic compounds (BVOCs) are important contributors to atmospheric chemistry and act as precursors of secondary organic aerosol, formaldehyde (HCHO) and carbon monoxide. In presence of high NOx the emitted isoprene may also contribute significantly to the production of tropospheric ozone. As such, having a good handle on BVOC emissions is important for global air quality analyses and forecasts, as produced operationally as part of the Copernicus Atmosphere Monitoring Service (CAMS). Currently, analyses and forecasts as generated using ECMWF’s Integrated Forecasting System for atmospheric composition (IFS-COMPO), use offline monthly datasets for biogenic emissions based on CAMS-GLOB-BIO. However, this approach lacks the ability to capture the daily variability in biogenic VOC emissions, while also the near-real time forecasts have to rely on climatological emissions.This has motivated the implementation of an online parameterization for the description of BVOC emissions based on the MEGAN scheme, as part of the ECLand module. Having the BVOC emissions as an integral part of the IFS allows the use of the latest parameterization of soil and vegetation properties, together with accurate description of meteorological quantities, which are both important drivers with respect to biogenic emissions. Also, the resulting emissions can be directly used in the atmospheric chemistry module, which has recently been updated with respect to isoprene chemistry. This also enables an indirect evaluation of the emissions using TROPOMI observations of HCHO.In this contribution we present the current status of the implementation of the online biogenic VOC emissions module into the IFS and provide a first assessment by comparing these emissions to a reference CAMS-GLOB-BIO dataset. Also we evaluate the resulting isoprene emissions in terms of HCHO columns using TROPOMI retrievals, along with its impact on surface ozone and secondary organic aerosol. We highlight uncertainties in different aspects along the parameterization and evaluation chain. 
Black carbon aerosol trend in urban regions of China during 2005-2022 using MERRA-2 and CAMS reanalysis
Authors: Yousefi Robabeh , Shaheen Abdallah , Wang Fang , Ge Quansheng , Wu Renguang
Published: March 2024

High atmospheric black carbon (BC) levels due to human activities pose a severe air pollution issue in China, especially in urban agglomerations. In this talk, we analyzed the trends of black carbon-aerosol optical depth (BCAOD) from Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2) and Copernicus Atmosphere Monitoring Service (CAMS) from 2005 to 2022.  Four densely populated and highly polluted urban regions (Beijing-Tianjin-Hebei [BTH], Sichuan Basin [SCB], Yangtze River Delta [YRD], and Pearl River Delta [PRD]) were selected for the analysis. BCAOD from MERRA-2 data showed significant negative trends over the four urban regions during the years 2005-2022, with rates of -0.0007, -0.0008, -0.0007, and -0.0006 yr-1 in BTH, YRD, SCB, and PRD, respectively. Similar significant BCAOD trends from CAMS were also observed in the urban selected regions with rates of -0.0005, -0.0006, -0.0009, -0.0006 yr-1 in BTH, YRD, SCB, and PRD, respectively. The decreasing trend in BCAOD could be mainly attributed to the air pollution policies implemented by the Chinese government.
Recent satellite-based radar and optical monitoring of the activity of a slow-moving landslide in Nepal during monsoon 
Authors: Leder Florian , Daout Simon , Lavé Jérôme , d'Oreye de Lantremange Nicolas , Lacroix Pascal
Published: March 2024

The steep Himalayan slopes are highly exposed to landslides, primarily triggered by earthquakes and monsoon intense precipitation. Along the Himalayan southern slopes, a specific landslide type involves old slided hillslope, characterized by intense internal fracturing, and prone to rapid retrogressive erosion through deep gullies incision, ultimately leading to catastrophic collapse of secondary landslides. Anticipating such events requires understanding if subsiding slices at the edge of the deeply incised talweg exhibit signs of acceleration preceding their rapid collapse and establishing a potential relationship between triggering factors (such as rain) and displacement amplitude. While optical images are commonly used for rapid landslides (with displacements superior to 20 cm/yr), their effectiveness is hindered by cloud cover during monsoon period, limiting sampling frequency and impeding the identification of transient deformation signals.In this study, we integrated satellite-based optical and radar remote sensing data with high spatial and temporal resolution to characterize the dynamics of a slow-moving landslide located in the Marsyandi valley (84.418° E ; 28.411° N ; 1900m a.s.l.) in Nepal, and to understand how it responds to monsoon rainfall. We developed a processing chain to apply sub-pixel image correlation to a data set comprising spotlight TerraSAR-X and PAZ radar images (1m spatial resolution), as well as medium resolution Sentinel-2 (10m), and high-resolution Pleiades (1m) amplitude optical images. We derived time series of ground displacements in range, azimuth, east-west, and north-south directions. Vertical displacements were additionally produced by comparing high-resolution Digital Surface Models (DSM) obtained from tri-stereo Pleiades images. The displacement time series revealed metric transient ground displacements in the upper part of the landslide at the end of the monsoon, along with linear displacements in downstream gullies. Field observations validated our satellite measurements, indicating that during the monsoon, the south-eastern part of the landslide remained relatively stable and revegetated, while the north-western part experienced downward sliding. By comparing these displacements with precipitation data, we characterized the response of the slow-moving landslide to seasonal forcing and gained insights into the mechanisms of collapsed hillslopes.
An 8000 yr lacustrine paleoseismic record (Lake Iznik, NW Türkiye): Implications for the seismic cycle of the Middle Strand of the North Anatolian Fault
Authors: Duarte Edward , Sabatier Pierre , De Sigoyer Julia , Gastineau Renaldo , Anselmetti Flavio S. , Rapuc William , Fabbri Stefano C. , Domenge Jarod , Şahin Mustafa , Gündüz Serkan
Published: March 2024

Lacustrine sediment sequences can provide long and complete records of earthquake recurrence patterns due to their continuous nature of subaqueous sedimentation. This gives this “natural seismograph” a high sensitivity for registration of seismic shaking and accurate age-depth control, these characteristics are important parameters for high-quality seismic hazard assessments. As the middle strand of the North Anatolian Fault (MNAF) is a slow slipping fault (5 mm/yr), a long-term earthquake chronicle is required to study its behavior. Here, we report on ﬁndings from three long sediment cores (from 8.5 to 15 m), retrieved in Lake Iznik (northwest Türkiye), crossing the Iznik underwater fault, that provide insight into the local and regional earthquake cycle and thus improve the paleoseismic history for the NAF system over the last 8000 years. We used radiocarbon-based age-depth models combined with sedimentological observations, X-ray fluorescence elemental data, and seismic reﬂection data to reconstruct the spatiotemporal rupture variability. Recurring millimetric, coarse-grained laminae identified as event deposits were deposited synchronously at the three coring sites. Over the last 2000 years, the ages of the event deposits recorded in Lake Iznik correspond to the historical evidence of seismic activity reported along the North Anatolian Fault (NAF) system, allowing us to recognize regional earthquake-triggering mechanisms and assess seismic intervals. The event deposits are inferred to be earthquake-triggered, and the sensitivity to earthquake shaking in Lake Iznik is proportional to the sedimentation rate. Our record demonstrates that Lake Iznik has been repeatedly exposed to significant seismic shaking over the past 8000 years. Our data suggest that large earthquakes with moment magnitudes Mw >7 occur on the Iznik fault segment part of the MNAF with a mean recurrence interval of ~1000 years. At the regional scale period of seismic activity alternates with several hundred years of quiescence. This study allows us to investigate the timing of large paleoearthquakes over the last 8000 years, providing important input for seismic hazard assessment and increasing societal awareness and preparedness in the case of future catastrophic events along the MNAF.
Spatially differentiated impacts of climate change on the carbon sequestration potential of afforestation and reforestation
Authors: Mathesius Sabine , Gerten Dieter
Published: March 2024

Removal of CO2 from the atmosphere (CDR) will most likely be required to reach the goal of the Paris Agreement to limit global warming to well-below 2°C above pre-industrial temperature, in addition to rapid reduction of greenhouse gas emissions. Re-/afforestation (A/R) is among the most prominently discussed CDR methods, as it can be realized at low cost and is already implemented in many places today. However, forests are vulnerable to various disturbances caused by climate change, such as wildfires, droughts, and heat stress, which can lead to a decreased CO2 uptake or even a release of previously stored carbon back to the atmosphere. There is still a high uncertainty on the effects of climate change on the CDR potential of A/R. Here, we show spatially explicit how climate change affects the potential of A/R to sequester and store carbon under severe climate change (SSP3-7.0) and moderate climate change (SSP1-2.6), as simulated by the dynamic global vegetation model LPJmL5. Utilizing a highly stylized global afforestation scenario, we explore changes in net primary productivity, soil respiration and CO2 emissions from fires and identify the region-specific underlying causes (such as soil moisture changes or heat stress). We also demonstrate to what extent CO2 fertilization could counteract detrimental effects of climate change and highlight the possibility to underestimate climate impacts by overestimating the CO2 fertilization effect. By revealing and explaining spatial patterns of simulated future climate impacts on the CDR potential of A/R, our study contributes to a more profound understanding of the role A/R might be able to play in removing CO2 from the atmosphere.
Analysis Techniques for Future Multipoint, Multiscale Observatories
Authors: Klein Kristopher , Broeren Theodore
Published: March 2024

Turbulence is three-dimensional, multiscale disorder. Characterizing turbulence requires determining how energy is injected into, transported through, and removed from these systems. One can study the three-dimensional structure by using measurements from at least four spatial points combined with appropriate analysis approaches to estimate spatial gradients and distributions of power at a given scale. Such techniques have been applied to data from spacecraft missions such as MMS and Cluster, but are limited to a single scale associated with the average inter-spacecraft distance. Given that future selected and proposed spacecraft missions, including HelioSwarm and Plasma Observatory, will have many more than four measurement points, with separations between the spacecraft spanning different characteristic spatial scale lengths, we consider the extension of previously implemented analysis techniques to these multipoint, multiscale configurations. In particular, we consider the propagation of measurement error through the wave telescope technique as a function of the number of measurements points and configuration to demonstrate the impact on accurate resolution of the underlying wavevectors. We also explore the optimal selection of subsets of measurement points to more accurately measure the properties of plane waves and wave packets with wavevectors spanning the spatial scales encompassed by a representative multispacecraft observatory.
Investigating the role of air-sea heat flux for marine heatwaves in the Mediterranean Sea
Authors: Denaxa Dimitra , Korres Gerasimos , Bonino Giulia , Masina Simona , Hatzaki Maria
Published: March 2024

The Mediterranean Sea (MS) has been experiencing progressively intensified Marine heatwave (MHW) conditions over the past decades, associated with severe environmental and socioeconomic impacts. Building upon prior research on physical mechanisms underlying the occurrence of MHWs, here we assess the relative role of air-sea heat exchange in driving the onset and decline phases of surface MHWs in the basin, utilizing remote sensing and reanalysis data for the period 1993-2022. Although contributing positively to the SST evolution during most MHWs, surface heat flux is identified as the primary driver in less than half of the onset/decline MHW phases. This finding suggests that oceanic processes play a crucial role in driving SST anomalies during MHWs in the basin. The role of surface heat flux becomes more pronounced during onset periods and warmer seasons, with the latent heat being the most significant heat flux component in modulating SST anomalies during both MHW phases and across all seasons. Heat flux emerges as the major driver of most onset phases in the Adriatic and the Aegean Seas. Onset/decline phases shorter than 5 days exhibit a weaker heat flux contribution compared to longer phases. Moreover, an inverse relationship between event severity and heat flux contribution is observed. At the subsurface, mixed layer shoaling is observed over the entire duration of most events, particularly for those of shorter duration. Therefore, the surface cooling right after the peak intensity day is likely not associated with vertical mixing in such cases. After the MHW end day, a significant mixed layer deepening in most cases suggests that further dissipation of heat is commonly driven by vertical mixing. This study emphasizes the need for considering subsurface information for MHW studies and accounting for limitations associated with the definitions employed for MHW phases. Clearly articulating such choices, tailored to the specific contexts of individual studies, is vital for precise interpretation and meaningful comparisons across different studies on MHW drivers.
Environmental Impacts of Developing Flood Protection Systems throughout a Marshland Ecosystem in Lower Louisiana: a Numerical Case Study
Authors: Barreca Daniel
Published: March 2024

Louisiana is a state in the United States of America that is experiencing the multiple challenges of climate change, extreme weather events (such as hurricanes), and human intervention impacts for flood protection. The marshland regions of lower Louisiana have been heavily impacted by human influence, since the state was originally formed and maintained by deposition of sediment carried from the Mississippi River. Not only has impact of human intervention impacted the sediment transport processes, but there has also been significant human development of levee systems and other flood protection structures in Louisiana’s coastal environment. Specifically after Hurricane Katrina, additional levee systems, environmental control structures, and floodgates were built in this marshland region. A few different design criteria are important to analyze for these systems, some of the more notable design criteria are flood protection, navigational safety for ships passing through floodgates, marshland protection, water quality, and system biology. In addition to monitoring human impacts, the US Army also seeks to understand how the system behaves under long-term climate change impacts.While flood protection is a primary motivator for building these systems, it is important to ensure that structures built do not have adverse effects on the local wildlife or commercial/recreational opportunities for the locals in these areas. Adaptive Hydraulics (AdH) is a finite element based 2D shallow water equation solver that can be used to numerically evaluate these impacts. Another focus of this study is to analyze the indirect impacts of structures built since 2004. To ensure that everything built since then has not had major impacts on the local wildlife or commercial/recreation opportunities, AdH and PTM can also be used to gain insight into that impact. The numerical modelling portion is the author’s direct contribution to the project, though the overall project of developing Lower Louisiana, and its impact of that and climate change on the natural environment and local people will be discussed.
Carbonaceous aerosols in restaurants: optical properties and possible impact on climate
Authors: Mandal Debayan , Chakraborty Abhishek , Tripathi Shruti
Published: March 2024

Organic carbon is a significant constituent of PM2.5. The organic carbon percentage in indoor microenvironments is higher than in the ambient environment. Water soluble organic carbon (WSOC) is responsible for altering hygroscopicity, hence determining the ability of particles to act as cloud condensation nuclei (CCN). In this study, quartz fiber filters were collected from two restaurants (R1 and R2 ) using an Airmetrix low-volume sampler at a 5 lpm flow rate. R1 was a closed restaurant where dining tables and the cooking locations were adjacent to each other. R2 was a semi-indoor environment; two sides of the dining place were open with adjoining dining tables, and cooking locations. Organic carbon (OC), elemental carbon (EC), and water-soluble organic carbon (WSOC) were estimated using DRI thermal optical analyzer and total organic carbon analyzer instruments. All these constituents can exfiltrate outdoors and alter the climate. Absorption coefficient (babs)  and Mass Absorption Efficiency (MAE) were calculated for Water-soluble carbon at 365 nm. Average OC and EC concentrations were very high in R1, i.e. 160.31 µg/m3 and 14.99 µg/m3,respectively. It was lower in R2, i.e., 29.61 µg/m3 and 4.88 µg/m3,respectively. As there was a direct biomass burning source, i.e., cooking, the major portion of the OC was POC. In R1, the average POC was ~67%, and in R2, ~60% of the total OC. The average WSOC percentages in the R1 and R2 were 8.01% and 25.21%, respectively. MAE values were comparable, i.e., 0.04 and 0.03 in R1 and R2, as the nature of the source was similar. Brown Carbon (BrC) absorption peaks at 365 nm were observed in both locations, confirming its presence. A negative correlation was observed between babs and WSOC, indicating BrC as the main absorption component of the WSOC. The effective carbon ratio (ECR= SOC/[POC+EC]) was calculated to estimate the impact of the particles on the local radiative energy balance. The values were 0.42 in R1 and 0.51 in R2. Aerosol generated from both locations was more absorbing in nature than scattering. In the R1, the aerosol had more absorption capability than in R2 . This study did not quantify the amount of  WSOC and BrC from different food and cooking fuels. But, from this study, it was noticed that cooking-related aerosols are absorbing in nature and can exfiltrate outdoors and alter the local climate.Keywords: Water Soluble Organic Carbon, Mass Absorption Effiency , Effective Carbon Ratio, Brown Carbon
Tianwen-1 and MAVEN Observed Multiple Ion Escape Channels of Mars during an Interplanetary Coronal Mass Ejection
Authors: Qiao Fuhao , Li Lei , Xie Lianghai , Li Wenya , Kong Linggao , Tang Binbin , Jin Taifeng , Zhang Yiteng , Zhang Aibing , Wang Limin , Ma Jijie
Published: March 2024

Interplanetary coronal mass ejections (ICMEs) are solar transients that have significant effects on the Martian space environment. The simultaneous spacecraft observations from Tianwen-1 and Mars Atmosphere and Volatile Evolution (MAVEN) are used to study the planetary ion escape for a dramatic ICME. MAVEN passes through the upstream solar wind, +E hemisphere, and -E hemisphere in one orbital period at 20:00 UT -24:00 UT on 2022 April 24. During this period, the interplanetary magnetic field (IMF) remained stable and dominated by the +Y component. In addition to the well-known “plume” escape channels located in the +E hemisphere, MAVEN also observed one ion escape channel in each hemisphere. The additional escape channel located in the +E hemisphere was easily identified as ionized atoms originating from the exosphere, which became significant during CME and was first reported. These ions are observed in both the solar wind and the magnetosheath, and the observed flux of these ions is strongest when MAVEN is very close to the upstream of the bow shock. In this event, ion density of this channel is up to 0.03 cm-3, which is 10 % ~ 30 % of the observed plume. The escape channel structure in the -E hemisphere is complex, and MAVEN has insufficient observation of this channel due to its orbital inclination. Tianwen-1 provided a powerful supplement based on the 1.5 hr observation of this structure, revealing many characteristics of this escape channel. The channel in the -E hemisphere also shows a narrow band in the energy spectrum, similar to the plume. Moreover, its density is between the ion densities of the two +E hemispherical channels. Interestingly, it is more likely to be observed near the magnetic pileup boundary rather than the entire -E hemisphere magnetosheath. These new channels reveal more details of Martian ion escape. The solar wind conditions similar to the early solar system during the ICMEs also help to study the early evolution of Mars.
How is microbial metabolic power distributed throughout the soil pore network?
Authors: Nunan Naoise , Maestrali Maëlle , Wu Haotian , Schwitzer Steffen , Raynaud Xavier
Published: March 2024

Soil microbial communities live within a complex three dimensional pore network, the properties of which constrains microbial life and activity. The physical structure of soil, and the associated pore network, limit microbial access to resources. It also determines micro-environmental conditions (e.g. redox conditions) that can affect microbial use of the available resources and the rates at which they use energy. Whilst the distributions of different types of activities (CO2 production, enzyme activities) in the pore network have received some attention, the rate at which microbial communities use the energy available to them, i.e. metabolic power, has received little. Energy is required for most aspects of microbial functioning and the rate at which this energy is used determines the extent to microbial functioning proceeds.Linking the energy available to the rate at which it is processed at the pore scale may help us to better understand how microbial growth and C dynamics are constrained by the physical environment in soil. In order to do so, we collected data from papers in which isotopically-labelled organic substrate was added to pores with different neck diameters and calculated the microbial community catabolic rates, the Gibbs energies of the reactions in oxic and anoxic conditions. This allowed us to estimate the distribution of microbial metabolic power in the pore network and of carbon use efficiency using the approach in LaRowe and Amend (American Journal of Science, Vol. 315, March, 2015,P.167–203, DOI 10.2475/03.2015.01). We then compare the calculations with laboratory measurements of the distribution of carbon use efficiency at the pore scale. 
Non-linear softening and relaxation in rocks and geomaterials: a laboratory perspective
Authors: Asnar Manuel , Sens-Schönfelder Christoph , Bonnelye Audrey , Dresen Georg , Bohnhoff Marco
Published: March 2024

In rocks and other consolidated geomaterials, static or dynamic excitation leads to a fast softening of the material, followed by a slower healing process in which the material recovers all or part of its initial stiffness as a logarithmic function of time. This requires us to exit the framework of time-independent elastic properties, linear or not, and investigate non-classical, non-linear elastic behavior and its time dependency. Softening and healing phenomena can be observed during seismic events in affected infrastructure as well as in the subsurface. Since the transient material changes are not restricted to elastic parameters but also affect hydraulic and electric parameters as well as material strength – documented for instance by long lasting changes in landslide rates – it is of major interest to characterize the softening and recovery phases. To characterize this behavior in a controlled environment, we perform experiments on Bentheim sandstone in a Materials Testing System triaxial cell with pore pressure and confining pressure control. Our sample is subjected to various static loading cycles in both dry and water-saturated conditions, while an active acoustic measurement setup allows us to monitor minute P-wave velocity changes, which can then be directly tied to dynamic elastic modulus changes.Our transducer array allows us to observe the dynamic softening as well as the recovery processes in the sample during repeated loading phases of various time lengths. Observations indicate high spatial, frequency and lapse-time sensitivity of the observed velocity changes, indicating a rich landscape of concurrent effects and physical phenomena affecting our sample during these simple experiments. To investigate the spatial and directional dependency of the velocity changes, we restrict the analysis to direct and reflected ballistic waves. Our observations indicate that, while stress-induced classical effects are clearly anisotropic as expected, the non-classical effects do not exhibit significant anisotropy. This allows us to rule out a number of physical phenomena as the cause for the non-classical effects. Most importantly, we conclude that the microscopic structures responsible for the reversible softening and healing processes are different from the cracks that induce the anisotropic acousto-elastic effect.
Chemo-Hydro-Mechanical variational phase-field fracture model 
Authors: Mollaali Mostafa , Lu Renchao , Yoshioka Keita , Wang Wenqing , Montoya Vanessa , Kolditz Olaf
Published: March 2024

We present a fully coupled chemo-hydro-mechanical variational phase field model for simulating fracture initiation and propagation, including chemical reactions in cementitious systems. Using a staggered approach, we coupled three subprocesses: (i) fluid flow in porous media, (ii) reactive transport, and (iii) mechanical deformation of fractured porous media using a variational phase field. The geochemical package PHREEQC was coupled in an operator-splitting approach with a finite element transport solver to calculate chemical reactions in thermodynamic equilibrium (dissolution or precipitation), considering changes in porosity. Mechanical deformation and fluid flow were coupled using the fixed-stress splitting approach. For chemical damage, we introduced a variable to a constitutive relation representing a degree of chemical damage ranging from zero (intact) to one (damaged material). This chemical damage variable represents changes in porosity caused by chemical reactions independently from the phase field variable that represents the mechanical damage.Additionally, as effective diffusion and hydraulic conductivity increase in the presence of fracture and changes in porosity, the phase field variable and chemical damage should impact the hydraulic conductivity and the diffusion coefficient. We conducted different benchmarks to demonstrate the model's capabilities and properties in capturing fracture initiation and propagation due to chemical reactions. The proposed model was implemented in the open-source finite element framework OpenGeoSys. 