bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimizing the Multifunctionality of Tropical Peatland Ecosystem
Authors: Rossita Annuri , Boer Rizaldi , Hein Lars , Riqqi Akhmad , Nurrochmat Dodik
Published: February 2023

Ecosystem Services (ES) study, which initially intended to capture externalities produced by economic activity, currently has been developed and expanded into numerous global frameworks. The multidimensional approach made the ES study applicable to a wide-ranging ecosystem, including peatland. While abundant research on spatial peatland ES has been carried out, only a fewest that attempted to use common drivers in deriving multiple ES. This study set out to value and map four peatland ES: provisioning, carbon regulating, water storage, and fire prevention services, using the common driver of land cover and peatland soil moisture. We exclusively apply the ES mapping concept to the status quo condition (2017), regional spatial planning (RTRW), and Indonesia’s Long Term Strategy (LTS) scenario for the peatland ecosystem unit of Gaung-Batang Tuaka KHG in Riau, Indonesia. Our results revealed provisioning services were at the highest to be produced under the RTRW scenario, particularly in the cultivation zone, with an additional USD 37.03 million in benefits for provisioning services compared to the status quo. However, the RTRW scenario failed to increase the carbon services, both in the ecological zones for cultivation and protection. For the Indonesia LTS scenario, immediate restoration using peat native commodity potentially add benefit from provisioning services amounted to USD 9.23 million while generating lower total emissions. However, spatially, negative carbon services were still dominating the study area in all three scenarios, which indicates ecosystem failure to regulate carbon. Omitting the peat subsidence factor, both RTRW and LTS scenarios are able to increase water storage services, while for the fire prevention services, changes in future rainfall due to climate change cause an increasing peatland burning area. While ecologically the LTS scenario performs the most optimum condition for both market and non-market benefit, the current system of valuing environmental benefits that neglects other essential ES beyond carbon is not aligned with the country's attempt to decarbonize the land sector.
Evapotranspiration: spatial variability in semiarid terrain at the sub-daily scale
Authors: Cuxart Joan , Boone Aaron , Price Jeremy , Groh Jannis , Martínez-Villagrasa Daniel
Published: February 2023

An experimental campaign was organised in summer 2021 in the Eastern Ebro basin, in the frame of the LIAISE Initiative (Land surface Interactions with the Atmosphere over the Iberian Semi-arid Environment). Amongst other measurements, the surface energy budget were obtained over different surfaces, including irrigated crops and orchards, rainfed areas and a lake, all them within a radius of 10 km.For dry weather conditions, the values of the latent heat flux (or Evapotranspiration, ET) were very different depending on the surface, varying from more than 500 W/m2 over an irrigated corn field to less than 30 W/m2 over dry bare soil. These different values implied also different sensible heat fluxes, with the irrigated surfaces showing thermal stable stratification in the afternoon well before sunset due to the cooling effect of evaporation.The contrast between the irrigated and the rainfed areas is very well-marked induced mesoscale circulations and local transport of humidity, which were overruled by the sea breeze arrival in the afternoon. Over the semi-arid rainfed areas, ET proceeded very irregularly in time and challenged the fundamental hypotesis of stationarity for the computation of the turbulent fluxes. Over all the well-watered surfaces, classical estimates of Potential ET, such as Penman-Monteith or Priestley-Taylor, overestimated the observed values.
Numerical and Analogue Modelling of Salt-Bearing Rifted Margins
Authors: Bakhtbidar Mahdi , B. Ruh Jonas , Santolaria Otín Pablo , Martinez Granado Pablo , Gratacos Torra Oscar
Published: February 2023

Due to their high economic (natural resources) and scientific (e.g., global archive of climate changes) potential, rifted margins have been studied using different approaches including sequence stratigraphy, high-resolution mapping, structural analysis, or seismic imaging. Sandbox analogue modelers have also assessed rifted margins and tested the driving and controlling parameters that determine their structural styles and evolution. In this research, we present a series of physical analogue models aimed at testing the influence of downbuilding and dominant gliding instabilities on the evolution and configuration of salt-bearing rifted margins. Being aware of the limitations of this experimental technique we go a step further and use numerical modelling to implement parameters that are not easy to simulate using analogue modelling. Several numerical experiments have been defined to test the main governing mechanisms (differential loading vs dominant gliding) and different key parameters such as the rheology of salt and temperature.Comparison of the two approaches yields valuable insights into the processes that control the evolution and structural styles of salt-bearing rifted margins as well as clarifies the limitations and complementarity between both techniques. Our models provide stratigraphic, structural and kinematic templates to better understand salt-bearing rifted margins worldwide.
Progress in high-resolution isotope-ratio analysis of tree rings using laser ablation
Authors: Saurer Matthias , Sahlstedt Elina , Rinne-Garmston Katja , Lehmann Marco , Oettli Manuela , Gessler Arthur , Treydte Kerstin
Published: February 2023

Stable isotope ratio analysis of tree rings has been widely and successfully applied in recent decades for climatic and environmental reconstructions. These studies were mostly conducted at an annual resolution, considering one measurement per tree ring, often focusing on latewood. However, much more information could be retrieved with high-resolution intra-annual isotope studies, based on the fact that the wood cells and the corresponding organic matter are continuously laid down during the growing season. Such studies are still relatively rare, but have a unique potential for reconstructing seasonal climate variations or short-term changes in physiological plant properties, like water-use efficiency. The reason for this research gap is mostly technical, as on the one hand sub-annual, manual splitting of rings is very tedious, while on the other hand automated laser ablation for high-resolution analyses is not yet well established and available. Here, we give an update on the current status of laser ablation research for analysis of the carbon isotope ratio (δ13C) of wood, describe an easy-to-use laser ablation system, its operation and discuss practical issues related to tree core preparation, including cellulose extraction. The results show that routine analysis with up to 100 laser shot-derived δ13C-values daily and good precision and accuracy (ca. 0.1‰) comparable to conventional combustion in an elemental analyser are possible. Measurements on resin-extracted wood is recommended as most efficient, but laser ablation is also possible on cellulose extracted wood pieces. Considering the straightforward sample preparation, the technique is therefore ripe for wide-spread application. With this work, we hope to stimulate future progress in the promising field of high-resolution environmental reconstruction using laser ablation.
Analysis of Wildfire Hotspots in Using Copula for Climate Indicators in Kalimantan, Indonesia.
Authors: Sopaheluwakan Ardhasena , Najib Mohamad Khoirun , Nurdiati Sri
Published: February 2023

Copula approach is a powerful method for analyzing the relationship between two or more data distributions and dependencies, especially those which are not normally distributed. The applications of copula in climate research has increased significantly, however there are only few applications of copula related to wildfires and hotspots.

In this research we analyze the effect of climate indicators on hotspots in Kalimantan, using coupled multivariate approach. Three local climate indicators are used: total precipitation, precipitation anomaly, and dryspell, while the ENSO index is used as an indicator of global climate.

The inference of functions for margins (IFM) method is used because of its ease of estimating the copula parameters. Various univariate distributions and copula functions are used to accommodate differences in the data distribution characteristics for various ENSO phases. Of the three local indicators, total precipitation and dryspells provide sufficient correlation to hotspots. Using the selected copula, the joint distribution of total precipitation and the number of dry days was estimated and analyzed.

The dependency structure of the copula varies according to seasons and the ENSO phase. The joint distributions between local climate indicators and hotspots have also been estimated and analyzed. A copula regression model was constructed from the joint distribution and a probabilistic model approach has also been constructed. This approach provided an improved understanding of seasonal and ENSO dependency to wildfire phenomena, where it can be applicable for early warning purposes.
Numerical modelling of ice forming and thawing in a subsurface energy storage application
Authors: Gerasimov Tymofiy , Naumov Dmitrii , Nagel Thomas , Kolditz Olaf , Shao Haibing
Published: February 2023

In the context of shallow subsurface ice storage, low temperature coolant fluid is circulated through multiple borehole heat exchangers (BHEs) to form ice in the surrounding soil. This can be used later on in building cooling applications. To evaluate the environmental impact of freezing and thawing cycles, we extended the classical Thermal-Hydro-Mechanical model in the OpenGeoSys software platform to simulate the aforementioned phase change scenarios.The new feature development and verification is divided into several subsequent steps. In the model verification, the Stefan problem of slab melting is employed as the benchmark case: the numerical results from OpenGeoSys is verified against the available analytical solution. In the subsequent code verification, the concept of manufactured solution is adopted, in which the numerical outcome is compared with the reference data to show accurate agreement. Following that, the ultimate verification is conducted by comparing results from OpenGeoSys and the open source package like FreeFEM++.For the application of the extended numerical model, we simulate the ice formation around the four BHEs in 3 dimensions for a quarter of the test field setup and over a period of 30 days. With -15 oC temperature imposed on the lower section of the BHE wall and the considered material data, the numerical simulation suggests an up to 50 cm thick layer of frozen soil surrounding the borehole. In the model results, major volumetric deformation of soil is observed in the close vicinity of the BHEs where the ice grows, also triggering small vertical surface elevation. Current on-going work is focusing on the coupling effect between thermal conductivity of soil, mechanical deformation and hydrology, where one of the envisioned impacts is the groundwater flow deviation due to the ice formed.
On the Response of the near-Mercury Environment to Different Interplanetary Conditions from full-scale 3D Hybrid Simulations
Authors: Cazzola Emanuele , Fontaine Dominique , Modolo Ronan
Published: February 2023

While waiting for further insights from the upcoming data from the BepiColombo mission, this work presents some results from full-scale 3D hybrid (ions kinetic and electrons fluid) computer simulations of the near-Mercury environment under different interplanetary conditions. During its orbit Mercury passes from an high density high magnetic field intensity region (Perihelion) to a low density low magnetic field intensity region (Aphelion). Such environment change drastically influences the response of its magnetic environment, including the stand-off distance of both Bow-Shock and Magnetopause. Being these latter not distant from each other nor from the Hermean exosphere, such a dynamics may lead to important interactions between the planetary and interplanetary environments, as well as lead to unpredictable scenarios whenever the interplanetary conditions occasionally result more extreme than those average values curretly known.Here we aim to give more insights  into the near-Mercury environments under more significant interplanetary conditions by means of full-scale 3D multi-species hybrid simulations, including the Aphelion and Perihelion conditions known to date, as well as more extreme conditions, and compare these results with currently available in-situ observations and recent similar computer simulations. 
Tracing metabolic water in living tissues using triple oxygen isotopes
Authors: Herwartz Daniel , El-Shenawy Mohammed , Staubwasser Michael , Zύñiga-Reinoso Alvaro , Predel Reinhard
Published: February 2023

Animals and plants metabolize carbohydrates to acquire energy. The most common oxidant is air O2, which comprises a distinct negative Δ’17O anomaly. Vertebrate bones and teeth inherit this anomaly providing a tool to approximate metabolic rates, aridity or paleo atmospheric compositions. In order to directly trace the Δ’17O anomaly in invertebrates, plants or soil water, we have developed a technique to quantitatively extract water from any organic tissue without heating or freeze drying. The method is based on water transfer from the organic matrix to initially dry, hygroscopic CaCl2 salt in closed containers and is presented in detail by El-Shenawy et al. (this conference).A sprouted potato is examined as an example for respiration by plant roots. Clear negative Δ’17O anomalies derived from air O2 are observed within the water extracted from the tribes and especially the small fruits that only develop after prolonged time of spouting in a dark cabinet. Apparent evaporation trajectories evolve in δ18O vs. d-excess space, but these are mostly artifacts due to production of metabolic water with high δ18O within the potato and the tribes. Clearly, the production of such metabolic water within plants and soils must be accounted for, especially when interpreting δ18O vs. d-excess trajectories as evaporation slopes.We examined Insect body water from lab reared beetles and silverfish as well as free ranging specimens form the Atacama Desert in Chile. A large interspecies range in δ18O vs. Δ’17O is observed, which is mainly interpreted to reflect variable water acquisition strategies. Metabolic water derived from air O2 can make up large proportions of body water in some species, but not others. Respective body water mass balance models are presently constructed and will be presented.
Very short-lived halogens amplify recent and future ozone depletion trends in the tropical lower stratosphere.
Authors: Villamayor Julián , Iglesias-Suarez Fernando , Cuevas Carlos A. , Fernandez Rafael P. , Li Qinyi , Abalos Marta , Hossaini Ryan , Chipperfield Martyn P. , Kinnison Douglas E. , Tilmes Simone , Lamarque Jean-François , Saiz-Lopez Alfonso
Published: February 2023

Recent observational evidences show ongoing net ozone depletion in the tropical lower stratosphere (LS) since the late 20th century, in contrast to the overall stratospheric ozone recovery following controls in the Montreal Protocol to limit the production of long-lived ozone depleting substances. Such behavior is currently thought to be driven by dynamical transport accelerated by global warming. In contrast, the role of chemistry, i.e., the enhanced ozone depletion due to emissions of halogenated ozone-depleting very short-lived substances (VSLS) has been considered to be unimportant. Here we employ a chemistry-climate model with a comprehensive chemical scheme to demonstrate that VSLS chemistry accounts for around a quarter of the observed tropical LS negative ozone trend in 1998-2018. We attribute such an effect to chemical reactions with VSLS from natural and anthropogenic emissions in concert. Future projections show the persistence of the currently unaccounted for contribution of VSLS to ozone loss throughout the 21st century in the tropical LS, the only region of the global stratosphere not projecting an ozone recovery by 2100. Our results show evidence for the need of mitigation strategies for regulating anthropogenic VSLS emissions to preserve the present and future ozone layer in low latitudes.
Nature-based solutions in savanna-grasslands can be both uncertain and unstable
Authors: Pellegrini Adam , Hobbie Sarah , Reich Peter
Published: February 2023

Altering management of disturbances in savanna-grasslands, a biome spanning >20 million km2 and under extensive human management, can offset a substantial proportion of anthropogenic carbon emissions. Quantifying the long-term carbon accrual and storage can be challenging because much of the change occurs belowground and it requires an understanding of ecological processes in a diverse set of environmental conditions. Here, we focus on the role of altered fire regimes given ca. 3 million km2 of savanna-grasslands burn annually. Combining repeated measurements of total ecosystem carbon stocks in a 58-yearlong fire-manipulation experiment with a global dataset, we demonstrate that while fire management leads to large changes in carbon sequestration, its magnitude and persistence over time is highly variable. In the experiment, fire exclusion resulted in large increases in carbon in soil organic matter via increased aboveground biomass inputs and faster decomposition. Increased burning frequency decreased carbon but this was partly offset by increased inputs from fine root turnover. However, repeated measurements illustrated both the magnitude of the sequestration within a plot and the differences across treatments changed—and even reversed—through time due to changes in tree inputs following a disease outbreak. The global dataset revealed that in wet sites, carbon sequestered in trees is most important but in drier sites the sequestration in soil organic matter is most important. Within soils, much of the variability in carbon accrual was due to variability in how much woody biomass inputs changed, with drier sites experiencing large changes. Consequently, much of the variability in carbon accrual is due to variability in the amount of woody biomass inputs and decomposition into soils. Because trees can be highly sensitive to changing disturbance regimes in drylands we propose that using fire management to sequester carbon in soils can be highly uncertain and unstable through time.
Benthic foraminiferal assemblage changes during OAE 2 in the southern high latitudes - IODP Site U1516, Indian Ocean
Authors: Wolfgring Erik , Amaglio Giulia , Petrizzo Maria Rose
Published: February 2023

At Site U1516 (Mentelle Basin, southeast Indian Ocean, offshore western Australia), the International Ocean Discovery Program (IODP) Expedition 369 recovered an almost complete record of the Upper Cretaceous, including the Oceanic Anoxic Event 2 (OAE 2). Benthic foraminiferal assemblages indicate a distal, outer neritic to bathyal depositional environment. For a better understanding of the paleoenvironmental changes across the OAE 2, we analysed 32 samples for benthic foraminiferal abundance data. The dataset represents one of the few deep water benthic foraminiferal records of the OAE 2 in the southern high latitudes. The record of the OAE 2 can be subdivided in pre OAE 2, pre max-CIE, low CaCO3, and post low CaCO3 intervals. The interval of low CaCO3 content covers a prominent positive Carbon Isotope Excursion (CIE). The Cenomanian-Turonian boundary records an extreme decline in benthic foraminifera during OAE 2. The post low CaCO3 interval documents a strong repopulation event in benthic foraminifera. During the pre OAE2 and pre-max-CIE intervals, taxa like the calcareous deep-water gavelinellids, lingulogavelinellids and gyroidinids are dominant. In the overlying low-carbonate interval, the microfossil record documents a substantial increase in Radiolaria while foraminifera become a rare faunal element. Remarkable changes in benthic foraminiferal assemblage composition are recorded in the initial low CaCO3 interval directly underlying the maximum CIE. Rather than acting as the trigger, it appears that the max CIE merely interrupted environmental change in the bottom waters.  Furthermore, the comparison of pre- and post-CIE benthic foraminiferal assemblages highlights a distinct repopulation event during the post max- CIE interval mainly represented by a profound increase in the abundance of agglutinated foraminifera and the calcareous epibenthic taxon Osangularia. The dataset collected at Site U1516 documents one of the most complete benthic foraminiferal records across the OAE 2 that registers the Late Cretaceous environmental changes in the Southern Hemisphere.
Exploring lithological controls on drainage density in Santa Gracia, Central Chile
Authors: Lodes Emma , Scherler Dirk , Stammeier Jessica A. , Schleicher Anja , Loyola Lafuente Martín Andrés
Published: February 2023

The controls of drainage density remain a mystery, despite it being a fundamental attribute of landscape morphology. Studies have shown that dry climates with less vegetation or less-consolidated sediment often have higher drainage densities. It remains unclear, however, how lithology effects drainage density, and existing studies have mixed results. Here, we investigate a landscape in Central Chile where two adjacent granitoid plutons (a monzogranite and a granodiorite) have different drainage densities. Since the tectonic setting and climate are the same between the two lithologies, we hypothesized that lithological differences control drainage density through modulating groundwater infiltration and runoff. To test this, for each lithology, we quantified the density of streams, channel heads, and vegetation using a 1-m resolution LiDAR digital elevation model. In the field, we measured infiltration rates and surficial sediment grain size distributions. In the lab, we obtained major oxide compositions from bedrock samples using X-Ray Fluorescence, identified mineralogy within thin sections, measured the hydraulic conductivity of the bedrock, and obtained in-situ cosmogenic 10Be-derived denudation rates from hillslope and stream sediment samples. Our results show that the granodiorite has a lower drainage density, a more weatherable mineralogy (more abundant biotite, hornblende and plagioclase) and composition (lower levels of SiO2 and K2O and higher levels of Na2O and CaO), denser vegetation, and a larger average grain size. Infiltration rates and hydraulic conductivity are similar between the two rock types, and 10Be results suggest similar erosion rates between the two lithologies. Our results suggest that differences in grain size and/or vegetation cause the observed differences in drainage density. In addition, there may be differences in infiltration rates that were undetected by our measurements or were different in the past.
Geoethics: hammering out an interdisciplinary conversation
Authors: Fox Bethany , Dawson Kate , Trowler Vicki , Briggs Sophie , Massey Ruth , Fitzsimmons Alexandra , Marshall Tania , Riesselman Christina , Davidson Anna
Published: February 2023

Geoethics is not just a matter of geoscience, but involves complex transdisciplinary concerns with social, economic and cultural implications. Because of this, both geoethicists within geosciences and those working in social sciences and humanities are increasingly calling for dialogue across disciplinary silos. Drawing from our work on the British Academy funded interdisciplinary project, ‘Mining for Meaning: the Geoethics of Extractive Industries,’ we trace out what an interdisciplinary engagement with Geoethics might look like. As an earthly ethics that necessarily stretches beyond geological considerations to consider the socio-natural, cultural-spiritual and political-economic, any engagement with Geoethics demands conversations that bring geoscientific understandings into more explicit dialogue with ideas from the social sciences and the geohumanities (though not exclusively). Acknowledging the very real challenges of doing interdisciplinary work - from distinct understandings about research, knowledge and results, to disciplinary-specific technical terminology - we set out the core ideas underpinning Geoethical approaches in these domains. This lays important groundwork for crafting meaningful and indeed ethical conversations that stretch across these disciplines, but crucially, avoids the mining of other disciplines for useful concepts and metaphors, without due regard for their context, history and technical meaning – a form of disciplinary extractivism in itself. Animated by this anti-extractivism, the paper presents a reading of how the earth, ethics, knowledge and practices are understood from within the geosciences, social sciences and geohumanities respectively, charting out what we hope to be a useful frame of reference for working across these disciplines. We then use this analysis as the bedrock for discussing the potential of cross-disciplinary conversation. By critically responding to the relative strengths, limitations and offerings of each discipline’s conceptualisation of geoethics, we bring to the fore important interdisciplinary frictions, overlaps and potential collaborative directions. Taken together, we suggest that this two-part analysis offers scope for crafting meaningful conversations necessary for an interdisciplinary Geoethics. 
Nitrous oxide flux dynamics on agricultural grasslands in Western Finland
Authors: Aaltonen Heidi , Manninen Noora , Koskinen Markku , Hakkola Saana , Kling Virpi , Nousiainen Juha , Pihlatie Mari
Published: February 2023

Agricultural grasslands may act as carbon sinks, counteracting emissions caused by agricultural practices. Contrastingly, grasslands may also act as sources of Nitrous oxide (N2O). For example, in Finland, N2O emissions from grasslands total up to 30 % of the climate impact of milk production. The N2O emissions from grasslands are induced by the use of nitrogen fertilizers, crop management and various environmental factors. However, the dynamics of N2O production are complex and not yet fully understood. Successful mitigation of N2O fluxes from agricultural soils calls for better understanding of these dynamics and the finding of practical solutions for farmers.We measured greenhouse gas fluxes (N2O, carbon dioxide (CO2) and methane (CH4)) in May-September on five Finnish grasslands with varying soil types (organic and mineral) and vegetation (perennial grasses) in 2022. The grasslands were harvested and fertilized twice during the measurement period. Each grassland had a fertilized and nonfertilized plot. The fluxes were measured every second week, with a dark chamber method by using online gas analysers, from both plots and adjacent soil samples were collected each time for chemical analysis. Soil parameters (temperature, moisture and conductivity) were measured continuously on each plot.The measured N2O fluxes varied from -22.6 to 928 µg N2O m-2 h-1. All measured grasslands were N2O sources over the measurement period, with organic soils showing higher emissions. Statistical analysis showed that N2O fluxes were affected by soil moisture, soil type and pH, whereas the effect of fertilizers and harvests was not as clear. However, the harvests and fertilizers seemed to have a more profound effect on CO2 respiration. The results indicate, that environmental factors govern the changes of N2O fluxes in these agricultural grasslands, but there is a need for long term, continuous measurements.
Impact of a large isolated city on the mixed layer height during different weather conditions
Authors: Fenner Daniel , Christen Andreas , Chrysoulakis Nektarios , Grimmond Sue , Van Hove Melania , Kotthaus Simone , Meier Fred , Morrison William , Zeeman Matthias
Published: February 2023

Understanding how cities impact the atmospheric boundary layer is crucial for many processes such as air-pollution dispersion and concentrations, and is therefore important as part of weather and climate modelling. To improve modelling of those dynamic processes observation are critical as they inform development and evaluation of models, and enhance delivery of services to citizens and the management of urban infrastructure, which is vulnerable to different strengths of heat and pollutant exposure.During a year-long field campaign from Autumn 2021 to Autumn 2022 a comprehensive set of ground-based remote sensing observations were gathered in Berlin, Germany. These allow us to explore the impact of a large city on the regional atmospheric boundary layer. The campaign, undertaken within the European Research Council funded urbisphere project, involved a grid-like network of instruments in the densely built-up city centre, with ground-based remote sensing (e.g. automatic lidars and ceilometers ALC, Doppler-wind lidars) for mixed/mixing layer height (MLH) detection. Additional instruments were located along two perpendicular rural-urban-rural transects, with existing instruments in the city and surrounding region complementing the network. During Intensive Observation Periods (IOP) in spring and summer 2022 radiosonde releases within and outside the city during selected days allow air temperature, humidity and wind-distribution profiles in the atmospheric boundary layer to be investigated.This contribution showcases how an urban environment modifies the dynamics and convective cloud properties under varying regional-scale weather conditions. We focus on case studies for different synoptic conditions to show the extent of impact of a large city on the MLH within and beyond the urban area, including urban-rural contrasts, upwind-downwind effects, and intra-urban variability of MLH.
Pollution-derived Cl2 and Br2 boost oxidation power of the coastal atmosphere
Authors: Wang Tao ,   study team
Published: February 2023

The chlorine (Cl·) and bromine atom (Br·) are known to destroy ozone, and Br· accelerates the deposition of toxic mercury (Hg). However, their abundances, sources and impacts in polluted regions are not well understood. In this talk, we give an overview of recent measurements of significant levels of Cl2 and Br2— a producer of Cl· and Br·, respectively —in the coastal atmosphere of Hong Kong. We present field and laboratory evidence to show photodissociation of particulate nitrate being a major production pathway for daytime Cl2 and Br2 and reactive uptake of N2O5 on aerosols as an important nighttime source. Model-calculated and Cl· and Br· from these di-halogens have significant impacts on VOC oxidation, OH radical, ozone production, and Hg oxidation. The findings suggest that reactive halogens may play a larger role in the atmospheric chemistry and air quality of polluted coastal regions than previously thought and call for more research on this issue.
Survivorship of Planktonic Foraminifera in the Cretaceous-Palaeogene Transition: A Carbonate Demand Perspective
Authors: Kesen Kebenle , Punekar Jahnavi
Published: February 2023

The Cretaceous-Palaeogene (K-Pg) boundary interval is marked by the mass extinction of more than 50% of the larger more specialized Cretaceous planktic foraminifera, followed by the extinction of ~33% generalist species (short-term survivors) (Keller and Abramovich, 2009 Punekar et al., 2014). Adaptation strategies identified in Cretaceous planktic foraminifera assemblages within this biotic-stress interval include changes in the community structure through shifts in abundance of species and diversity decline. Changes on a species level are reported as inter- and intra- specific dwarfing, malformation and test-wall thinning. Guembelitria cretacea is typically small sized triserial species identified as the only long-term survivor of this event. Through this study, we test the ocean acidification hypothesis of the late Maastrichtian planktic stress by understanding the link between species carbonate demand and their survivorship at the K-Pg boundary.Four-dimensional X-ray microscopy (FDXRM) scans of pristine Cretaceous planktic morphogroups (the globotruncanids, the rugoglobigerinids and the planoheterohelicids) from pristine late Maastrichtian zone CF4 of DSDP 525A (South Atlantic) yield the most accurate estimation of their respective test calcite volume. The average test weights and the FDXRM reference estimates together suggest that the scaling of calcium carbonate for globotruncanids, planoheterohelicids, rugoglobigerinids, w.r.t. the guembelitrids is 10-269ug, 6-28ug and 9-60ug respectively. This scaling is significant in context of the observed survivorship of these morphogroups across the K-Pg boundary interval. The new results establish a preliminary link between the carbonate demand, ocean acidification related carbonate crisis (especially in the late Maastrichtian biozone CF1) and the survivorship of these morphogroups. However, other detrimental environmental factors in this critical stress interval cannot be ignored.
Evaluating the Capabilities of Backbones for Scanning Electron Microscopy Images of Opalinus Clay
Authors: Brysch Marco , Sester Monika
Published: February 2023

The characterization of pores in materials such as Opalinus clay is crucial for understanding the physical properties, including permeability and strength, which are important for the safe disposal of radioactive waste. Scanning electron microscopy (SEM) is a technique that allows high-resolution imaging of these pores at the nanoscale. However, the analysis of SEM images can be challenging due to the resolution limits of nanoscale pores and their manual segmentation. In the development of automatic segmentation methods, approaches of supervised or unsupervised machine learning (ML) and deep learning (DL) methods are increasingly applied. The main advantage of these methods is to achieve fast and more consistent results that do not rely on user input.An essential component in DL is the so-called backbones, which can learn object features that are necessary for object recognition. In image processing, objects are recognized through groups of specific features that allow an unambiguous identification. Pre-trained backbones, which have been trained on large datasets such as ImageNet containing millions of everyday images, possess a wide range of features that are useful during image processing tasks. However, specialized applications, such as the automatic analysis of microscope images using DL may require features that differ from those of pre-trained backbones. The limited availability of SEM images makes it difficult to effectively train DL models, as these models typically require a large amount of data to learn new features. In these cases, ML methods may perform better due to their ability to use carefully selected, expert-defined features [Maitre et al., 2019].In this study, the training behavior of eight different DL backbones was examined using a dataset of 2000 SEM images showing both the background and pores of an Opalinus clay sample. The backbones studied included VGG16, VGG19, ResNet50, Desenet, Xception, and Mobilenet. To train these models with the relatively small amount of training data available, a transfer learning technique was applied. We analyzed gradient-weighted class activation mappings (grad-CAM) [Selvaraju et al.,2019] during the learning process to obtain a general sense of the behavior of the different backbones. Through analysis of the model's adaptation efforts, the present study demonstrates which pre-trained backbones show good training behavior on SEM images and provides an estimation of the amount of data needed for effective training. References[Maitre et al., 2019] Maitre, J., Bouchard, K., and Bédard, L. P. (2019). Mineral grains recognition using computer vision and machine learning. Computers & Geosciences, 130:84–93.[Selvaraju et al., 2019] Selvaraju, R. R., Cogswell, M., Das, A., Vedantam, R., Parikh, D., and Batra, D. (2019). Grad-cam: Visual explanations from deep networks via gradient-based localization.
Elucidating cm-scale heterogeneity in soil biogeochemistry with a 13C pulse-chase assay
Authors: Kohl Lukas , Kiuru Petri , Palviainen Marjo , Raivonen Maari , Koskinen Markku , Matala Laura , Pihlatie Mari , Laurén Annamari
Published: February 2023

Spatial heterogeneity in the soil pore network is commonly understood to lead to spatially distinct biogeochemical transformations like the production of methane in anaerobic pockets in unsaturated soils. Yet, demonstrations of this heterogeneity and its linkage to soil structure (e.g., the spatial position in the soil pore network architecture) remains elusive.We therefore developed an assay to elucidate centimeter-scale differences in biogeochemical reactions within and between peat soil cores. For this, we injects a isotope-labeled substrate (sodium 13C2-acetate) at different locations in intact peat samples (10 cm diameter x 10 cm height) and followed its conversion to 13CO2 and 13CH4 over 5 days time in an automated measurement system using a Picarro G2201-i trace gas analyser. We analyse the ratio of 13CH4 and 13CO2 produced from the amended substrate, the fraction of substrate converted to 13CH4/13CO2, and the time course of 13CH4/13CO2 release. To test this approach, we collected seven pairs of peat core samples (15-25cm depths, 10 cm diameter, >30m between apart) at a drained forested peatland in Southern Finland. As one of the goals was to evaluate the effects of water retention hysteresis, half of the samples were set to -15 hPa water potential after draining to -30 hPa water potential, while the other half was set to same water potential after water-saturating the samples. In three experiments per core, we injected 10 nmol sodium acetate in 1mL water at 2, 5, and 8cm depth. We find both fixed effects (of core, injection depth, water treatment) and random effects that might be governed by the position of the injection with the peat core. We find, for example, that while a subset of the peat cores emitted (natural abundance) CH4, these cores showed highly heterogeneous conversions of the injected label into CH4 and CO2 that could not be explained by the fixed effects, demonstrating the spatial heterogeneity of methanogenesis and heterotrophic respiration within the peat core.In our future work, we will explore if pore networks models extracted from microtomographic images can explain these contrasting results. 
Understanding the double-ITCZ problem over the Atlantic with bias-corrected downscaling
Authors: Liu Shuchang , Zeman Christian , Schär Christoph
Published: February 2023

The long-existing double-ITCZ problem in GCMs affects not only the models' ability in simulating the current climate, but also implies limitations regarding the assessment of climate sensitivity and global climate change. Using a regional climate model (RCM) with explicit convection at a horizontal grid spacing of 12 km in a large computational domain covering the tropical and sub-tropical Atlantic, we develop a bias-correction downscaling methodology to remove the biases of a driving GCM. The methodology is related to the pseudo-global warming (PGW) approach. Normally this method is used to impress the climate-change signal to a reanalysis-driven RCM simulation, but it can also be used to modulate the lateral-boundary conditions of a GCM, such as to remove the large-scale biases. We show that the double ITCZ problem persists with classical dynamical downscaling (i.e. when driving the RCM directly by the GCM output), but with our bias-corrected downscaling the double ITCZ problem can be removed. Detailed analysis reveals that the main cause of the double ITCZ problem can be attributed to the GCMs' SST bias. Compared to the GCMs' AMIP simulations, RCMs with higher resolution allow explicit deep convection and enable a better simulation of tropical convection and clouds. By improving the corresponding radiative forcing, vertical motion is better simulated. Subsidence stronger to the south of the ITCZ pushes the ITCZ more north in the boreal spring, which is consistent with the observation of the ITCZ. The developed methodology provides an opportunity for better constraining climate sensitivity by removing double-ITCZ biases.
Monitoring daily cropland CO2-exchange at field scale with Sentinel-2 satellite imagery
Authors: Gottschalk Pia , Kalhori Aram , Li Zhan , Wille Christian , Sachs Torsten
Published: February 2023

The cropland carbon (C) balance at regional scale still contains high uncertainties not the least due to the problem of up-scaling C fluxes of temporarily and spatially highly divers ecosystems. The C-exchange between the terrestrial ecosystem and the atmosphere constitute the largest and most uncertain flux of the cropland C balance, as opposed to C import from organic (manure) and C export through harvest which are lower and less uncertain.Combining satellite data with local eddy covariance CO2-flux data is commonly used to up-scale the C-exchange signal from point to regional scale across global ecosystems. Low spatial resolution products like MODIS limit their applicability and accuracy to larger homogeneous areas involving a high degree of uncertainty rather than detecting and tracing highly dynamic (farm-)field scale CO2-fluxes from space. We are using eddy-covariance CO2-flux data of an arable field in conjunction with Sentinel-2 derived vegetation indices (VI) to assess the ability of the satellite data to monitor daily net-ecosystem exchange (NEE), gross-primary productivity (GPP) and ecosystem respiration (Reco) based on a matched footprint. Simple linear regression models are built to test the ability of a range of VIs (NDVI, GNDVI, EVI, EVI2, SAVI, MNDWI, NDWI, SR, S2REP) to monitor and predict CO2-exchange for croplands. We analyze the correlation between measured CO2-fluxes and VIs over the course of the growing seasons to assess the suitability and accuracy of the VIs along the phenological year. We present a single site analysis to zoom into short-comings of this approach and how the satellite signal relates to vegetation CO2-exchange. VIs generally show a high variability in their predictive power. Still, results suggest a similarly high accuracy as mechanistic modelling approaches for suitable VIs, e.g. the cumulative C-exchange (NEE) of winter wheat of one growing season based on NDVI and GNDVI is over- and under-estimated by only 33 (15%) and 41 (18%) g C m-2 respectively.
Multi-disciplinary investigation of water content and displacement evolution around the Mont Terri twin niches in Opalinus Clay
Authors: Ziefle Gesa , Cajuhi Tuanny , Costabel Stephan , Furche Markus , Kunz Herbert , Maßmann Jobst
Published: February 2023

Coupled hydro-mechanical effects in Opalinus Clay (OPA) are of significant interest regarding the  stability and integrity of a potential storage facility for high-level radioactive waste (HLW). In the Mont Terri Rock Laboratory, the CD-A twin niches differ only in their ventilation and enable the investigation of near field effects like desaturation and development of the excavation disturbed zone (EDZ). Amongst others, the evolution of water content and deformation are observed and provide a comprehensive data set as basis for a pragmatic approach to capture effects in the EDZ in safety assessment. The measuring campaign includes electric resistivity tomography (ERT), providing daily measurements of the electric resistivity distribution up to a few meters into the rock formation, as well as the nuclear magnetic resonance method (NMR) aiming on the evolution of water content near the surface of the niches. Due to the corresponding effort in handling the relatively new single-sided application, the NMR measurements are only conducted once per season. Nevertheless, the combined interpretation of NMR and ERT provides valuable data of water content and hydraulic conductivity evolution enabling a meaningful optimization of numerical modelling approaches. The interpretation of the water content evolution in combination with the geologic characterization demonstrates the high heterogeneity of the sandy facies of OPA, a significant impact of the ventilation, and a correlation of high resistivity regions with open fractures, indicating potential preferential flow paths that are relevant for transport processes. As a matter of fact, the results illustrate a need to discuss the set-up of numerical modelling, especially concerning the boundary conditions, the heterogeneities, and the parametrization and set-up of the EDZ. Further measuring focus on the displacements around the niches. While laser scans represent the convergence behavior near the surface, extensometers generate information about the displacements a few meters around the twin niches. Summarizing these data, the convergence behavior near the surface as well as a few meters around the twin niches depends significantly on the ventilation of the niches, indicating seasonal effects and differences in the long-term convergence behavior. Future work aims on an increased system understanding considering long-term effects due to climatic conditions, geotechnical boundary conditions, heterogeneities amongst others and their realistic representation in safety assessment.
Assessing ExxonMobil’s global warming projections
Authors: Rahmstorf Stefan , Supran Geoffrey , Oreskes Naomi
Published: February 2023

The performance of mainstream climate models has received extensive scrutiny. By contrast, climate projections by the fossil fuel industry have never been assessed. Based on recent archival discoveries, we quantitatively evaluate all available global warming projections documented by – and in many cases modeled by – Exxon and ExxonMobil Corp scientists between 1977 and 2003. We find that most of their projections accurately forecast warming consistent with subsequent observations. Their projections were also consistent with, and at least as skillful as, those of independent academic and government models. We find that Exxon and ExxonMobil Corp also correctly rejected the prospect of a coming ice age, accurately predicted when human-caused global warming would first be detected, and reasonably estimated the ‘carbon budget’ for holding warming below 2°C. Our results show that ExxonMobil predicted global warming correctly and that by the 1980s, they already knew how much global warming the company’s products were likely to cause.  
Quantification of source- and basin-induced surface waves effects on the seismic performance of nonlinear structures
Authors: Soto Valeria , Lopez-Caballero Fernando
Published: February 2023

The present paper focuses on the influence of Rayleigh and Love waves on the seismic structural performance of a simplified nonlinear beam structure representing a bridge column. The impact of surface waves in the structure is quantified directly by a coupled 3D SEM-FEM numerical wavepropagation simulation from the earthquake source to the structure using the Domain Reduction Method.In the first step, ground motions, including basin-induced surface waves, are generated from a regional model containing the earthquake source and a simplified basin. Surface waves are extracted and characterized with the Normalized Inner Product (NIP) in terms of amplitude andfrequency content from ground motions at different locations inside the basin. In the second step, the seismic wavefield from the SE simulation is imposed in a FE model composed of a nonlinear structure placed over a portion of the basin sediments. The model considers soil-structureinteraction and structural non-linearity through a multifiber beam approach.By placing the structure in different positions, the extracted surface waves and the structural damage can be linked to a specific location inside the basin. Therefore, the spatial variability of the structural damage and the surface wave characteristics can be quantified. Consequently, this workevaluates if structural damage can be estimated only from typical ground motion intensity parameters or if other parameters associated with surface wave characteristics are necessary. The results show a correlation between obtained seismic damage with rotational components fromsurface waves (torsion for Love waves and rocking for Rayleigh waves).