bluuebunny/crossref_metadata_2025 huggingface dataset:
Non-conventional oxidation of SO2 by iodine oxides: A source of nighttime sulfuric acid in the marine boundary layer
Authors: Kumar Avinash , Iyer Siddharth , Barua Shawon , Seal Prasenjit , Rissanen Matti
Published: March 2024

The formation of sulfuric acid (H2SO4, SA), a key aerosol precursor in the atmosphere, hinges on the rate-limiting oxidation of SO2. During the daytime, hydroxyl radical (OH) is the main SO2 oxidant, but the measured ambient SA concentration suggests the existence of other unaccounted pathways via other oxidants (Berresheim et al., 2014). The nocturnal presence of SA in marine environments is particularly interesting as the formation mechanism is not straightforward due to the lack of photochemical reactions. In marine environments, molecular iodine and iodocarbons are prevalent, and their reactions with the nitrate radical (NO3) are known sources of nighttime IO and OIO radicals (Saiz-Lopez and Plane, 2004). OIO has low daytime concentrations due to its large photolysis cross-section but can accumulate during nighttime. In the absence of a photolysis sink, OIO predominantly undergoes self-reaction, leading to the generation of the iodine oxide I2O4 at nighttime. The reported lifetime of I2O4 against the thermal decomposition back to OIO + OIO is about 30 seconds, which means that it is relatively short-lived, but can survive long enough for reactions with other atmospheric trace gases to become relevant (Kaltsoyannis and Plane, 2008).In this study, laboratory experiments for the reaction of iodine oxides with SO2 were carried out using a flow reactor coupled with a nitrate-based chemical ionization mass spectrometer (NO3--CIMS). The iodine oxides were generated in situ by the reaction of iodine vapors and ozone in the presence of nitrate radical, mimicking the nighttime oxidation of SO2 to form SO3 and consequently SA. The experiments were carried out at room temperature and atmospheric pressure conditions. The experiments were complemented by high-level quantum chemical calculations to get detailed insights into the mechanism and feasibility of the oxidation of SO2 by iodine oxides to produce SA. Among all the formed iodine oxides, I2O4 reacts sufficiently fast with SO2 with a rate coefficient of 2.0×10-14 molecule-1 cm3 s-1 and can thus lead to appreciable concentrations of SO3. These results suggest that I2O4 can be a key SO2 oxidant in the marine environment and explain a significant fraction of the produced SA in the nighttime.  References: Berresheim, H., Adam, M., Monahan, C., O'dowd, C., Plane, J. M., Bohn, B. and Rohrer, F.  Atmos. Chem. Phys. 14, 12209-12223, 2014.Saiz–Lopez, A. and Plane, J. M. Geophys. Res. Lett. 31, 2004.Kaltsoyannis, N. and Plane, J.M. Phys. Chem. Chem. Phys., 10, 1723-1733, 2008. 
Autogenic vs Subsidence Controls on Fluvial Stratigraphic Grain Size Fining through Multi-Channel Landscape Evolution Modelling
Authors: Wild Amanda , Braun Jean , Whittaker Alex , Castelltort Sebastien
Published: March 2024

Grain size within the stratigraphic record is often used to interpret changes in tectonics and climate. For example, past work has described the influence of underlying subsidence or flux oscillations due to climate on grain size fining rates within the basin. However, little research has deconstructed the role of internal dynamics in shaping the grain size fining rates preserved within strata under varied basin geometries, precipitation gradients, and bypass states of basin evolution. Through the combination of a landscape evolution model based on the Stream Power Law modified for sedimentation by Yuan et al. (2019) with an extension of the self-similar grain size model of Fedele and Paola (2007) into multiple dimensions (i.e., along dynamically evolving river channels) by Wild et al (in review), we have developed a steady-state framework identifying autogenic vs subsidence dominated grain size fining. When basin accommodation is high relative to incoming flux, or early in the basin evolution, grain size fining is primarily subsidence-dominated regardless of precipitation gradients and basin geometries. Alternatively, under high bypass and low underlying accommodation, grain size fining is autogenically dominated and controlled by relative upstream discharge (or the ratio of the upstream, mountain catchment area vs the downstream, sedimentary system area). Foreland basins (eg: the Alberta foreland basin) with ample downstream area tend to evolve from a high subsidence to autogenic dominated state as they fill over time. Constrained downstream areas (eg: Death Valley fans) display a minimal autogenic impact on grain size fining regardless of their bypass state. We will present our modelled stratigraphic results and compare them to natural systems, such as the Alberta Foreland basin and alluvial fans of Death Valley.
Polar Impact's Guide to Inclusive Fieldwork Experiences
Authors: Vurakaranam Amruta , Robertson Emma , Walcott Caleb , Gill Prem , C. Dryák-Vallies Mariama , Quinter Evan , Ihle Alex
Published: March 2024

Fieldwork is a key element in natural sciences, including polar sciences, yet there is a notable lack of representation of minorities in polar field expeditions. Despite the historical involvement of ethnic minorities in such expeditions, their role as contributors and experts in polar scientific knowledge has often been overlooked. In our efforts to promote diversity and inclusivity in the sciences, it is important to reshape fieldwork spaces. This entails providing support to help individuals navigate these spaces, particularly if they are engaging in polar fieldwork for the first time. Establishing resources and support networks is pivotal in this process. We aim to develop a comprehensive fieldwork guide accommodating scientists from underrepresented backgrounds while remaining valuable to a broader audience. Although many fieldwork resources exist, there is an absence of a multi-faceted and inclusive Polar-specific guide. Existing fieldwork guides primarily prioritise physical safety, overlooking crucial aspects such as accessibility, mental health, and insights from underrepresented minority (URM) field scientists. This specialised resource is imperative as exclusionary or negative fieldwork experiences can significantly hinder the retention and career progression of scientists from underrepresented backgrounds. Drawing on our experience as an international volunteer organisation dedicated to promoting inclusivity and accessibility in polar sciences, Polar Impact is uniquely positioned to develop such a fieldwork guide. Our mission focuses on supporting, connecting, and highlighting the experiences of Black, Asian, Indigenous, people of colour, and minority ethnic professionals in the polar research community. It does so by utilising personal experiences from our members and field experts, extensive surveys, and insights from existing guides. Through this expertise, we aim to bridge knowledge and representation gaps, crafting a guide that nurtures a more supportive environment for all scientists in polar research.
Capabilities of IGM, a thermo-mechanical glacier evolution model accelerated by deep-learning and GPU
Authors: Jouvet Guillaume , Cordonnier Guillaume , Maussion Fabien , Cook Samuel , Finley Brandon , Henz Andreas , Herrmann Oskar , Kamleitner Sarah , Leger Tancrede , Lleshi Kejdi , Mey Jürgen , Scherler Dirk , Welty Ethan
Published: March 2024

We present the concepts and capabilities of IGM (https://github.com/jouvetg/igm), a fast and accessible Python model that simulates the evolution of glaciers at any scale by coupling ice thermomechanics, surface mass balance, and mass conservation. IGM models the ice flow by physics-informed deep learning. Specifically, we use a convolutional neural network, which is trained to minimise the energy associated with high-order ice flow physics. Based on the Tensorflow library, IGM performs a suite of fast, vectorised, and differentiable operations, which can be accelerated with a graphics processing unit (GPU). In turn, this allows fully-parallelised implementations of key model components in glacier modelling applications such as the positive degree day surface mass balance scheme, the enthalpy scheme for modelling the thermal regime of ice, or the integration of a large amount of particle trajectories for modelling debris transportation. As a result, IGM combines coding simplicity and modularity, high computational efficiency, state-of-the-art thermomechanical modelling, and efficient data assimilation thanks to underlying automatic differentiation tools. We demonstrate the capability of IGM for two different applications. First, we present a complete workflow (including OGGM-based data preprocessing, inverse and forward modelling, rendering of results) that allows us to model any mountain glacier in the world within a few minutes requiring only its Randolph Glacier Inventory (RGI) ID. Second, we present an application in paleo glacier modelling by simulating the entire European Alpine ice field (about 800 km long) in high resolution (200 m) during the Last Glacial Maximum.
Baltic Sea ferromanganese concretion growth rates and conditions
Authors: Majamäki Renata , Purkamo Lotta , Hultman Jenni , Wasiljeff Joonas , Asmala Eero , Yli-Hemminki Pirjo , Jorgensen Kirsten , Koho Karoliina , Kuva Jukka , Virtasalo Joonas
Published: March 2024

The transition to renewable energy and the acceleration of technology demand vast amounts of hi-tech metals that are critical in green energy technology. Due to increasing demand for hi-tech metals, rising interest in mining from more unconventional sources, such as the seafloor, is inevitable. Ferromanganese concretions, which are centimeter-scale accumulations of iron and manganese oxides, are common in the Baltic Sea. In addition to iron and manganese, concretions contain hi-tech metals, such as cobalt. The Fe-Mn concretions are important reaction surfaces for diverse microbial communities, and they regulate metal and nutrient cycling in the concretions. Extraction of Fe-Mn concretions from the Baltic Sea could impact the seafloor ecosystem, biogeochemical cycling of elements, concretion growth, and recovery. This study provides information on Baltic Sea Fe-Mn concretion growth rates and conditions in laboratory experiments.The ferromanganese concretions were collected from the Baltic Sea during May and June 2022 for a 12-week laboratory incubation and metal tracer experiments. Triplicate concretion samples and one abiotic control sample were collected into bottles containing artificial brackish seawater and incubated in the dark at +5 °C in an orbital shaker at 100 rpm to imitate seafloor conditions. Bottles were sampled at the beginning and the end of the 12-week incubation experiment. We assessed the concretion growth with X-ray computed tomography and freshly formed concretion material with a scanning electron microscope. We analyzed the headspace methane concentrations and pH of the incubation solution. We measured phosphorus and metal (Mn, Fe, Co, V, Ni, Zn, Mo) concentrations of the incubation solution with triple quadrupole ICP-MS.The results provide new information on the growth rates and conditions of Fe-Mn concretions. It was confirmed that concretions grew in laboratory conditions, and new growth was as much as 10 µm in 12 weeks. Headspace methane concentrations decreased in all samples during incubation, but least in abiotic controls, where the microbial activity was eliminated. The microbes living on the surface of concretions utilized methane, indicating that concretions have methanotrophic communities. Incubation solutions’ metal analysis showed that metal concentrations increased more in the abiotic controls than in biotic triplicates after a 12-week incubation, thus metals dissolved from concretions into the incubation solution faster without the activity of microbial communities. We suggest that microbes occupying the concretions have an important role in the concretions’ growth and the factors affecting the accumulation and release processes of metals.This work was supported by the Finnish Natural Resources Research Foundation and the Research Council of Finland (Fermaid project, grant 332249).
Batch experimental results about the occurrence and fate of Gadolinium in aquifers  
Authors: Pujades Estanislao , Ekiz Mert Çetin , Scheiber Laura , Jurado Anna , Izquierdo Maria , Vázquez-Suñé Enric , Foppen Jan Willem
Published: March 2024

The use of groundwater as a freshwater source must be increased to mitigate the increasing pressure over water resources, resulting from growing population and climate change. However, many aquifers are commonly polluted by a wide range of anthropogenic substances, especially those aquifer located in urban areas. Therefore, to use groundwater resources safely, it is needed to establish the presence and fate of pollutants that can endanger human health. This is the case of Gadolinium. Integrated in Gadolinium-based contrast agents it is harmless and used for medical purposes, but it can cause serious health issues when released in the environment.This research arose during a water sampling campaign undertaken in Barcelona where Gadolinium anomalies (i.e., resulting from anthropogenic activities) were detected in surface and underground water bodies which were hydraulically connected. What was striking was that Gadolinium pollution in groundwater bodies was less frequent and at lower concentrations than in surface water bodies. These observations suggested that Gadolinium was attenuated during its transport through the subsurface. To establish the mechanisms controlling the attenuation of Gadolinium, laboratory based batch experiments were carried out and then modelled using PHREEQC. Experimental results suggested that main process affecting the concentration of Gadolinium was sorption which could reduce considerably its presence in groundwater. Our results contribute to understanding the fate of anthropic Gadolinium in aquifers which is of paramount importance to use groundwater safely.
Analysis of MSTIDs triggered by dynamical events
Authors: Buresova Dalia , Chum Jaroslav , Mani Sivakandan , Mielich Jens , Urbar Jaroslav , Barta Veronika , Belehaki Anna , Verhulst Tobias G.W. , Altadill David , Segara Antoni , Kouba Daniel , Guerra Marco , Koucka Knizova Petra , Mosna Zbysek , Berényi Kitti A. , Cesaroni Claudio , Spogli Luca
Published: March 2024

It is well known that the ionosphere is a highly dynamic medium, and the electron density can vary significantly within a very short period of time at a given location. One of the reasons for the irregular variations are ionospheric signatures of Atmospheric Gravity Waves (AGWs) – Travelling Ionospheric Disturbances (TIDs). TIDs are one of the major and frequent wave-like perturbations of the ionospheric plasma. Medium scale TIDs (MSTIDs) have been described as perturbations characterized by a wavelength, period and phase speed of 50–500 km, 12–60 min and 50–400 m/s, respectively. The wave-like effects of the MSTIDs are one of the main obstacles for accurate interpolation of ionospheric corrections in a medium scale reference of the Global Positioning System (GPS) networks as the ionospheric delay is almost proportional to Total Electron Content (TEC) along the signal path and inversely proportional to the frequency squared. MSTIDs are a common phenomenon from high to low latitudes.The main objective of the T-FORS project is the development of new validated models able to issue forecasts and alerts for TIDs several hours ahead, exploiting a broad range of observations of the solar corona, the interplanetary medium, the magnetosphere, the ionosphere and lower atmosphere. This paper presents our results on the analysis of dynamic events that trigger MSTIDs. The events identified for the purposes of the analysis were such as geomagnetic disturbances, deep tropospheric convections, earthquakes and volcano eruptions. Based on the T-FORS methodologies all available data (detrended TEC, Continuous Doppler Sounding System -CDSS measurements, Digisonde vertical and oblique soundings and gradients of the electron density, reference meteorological and seismic data) were used for this analysis. The MSTIDs occurrence was recorded and analysed and propagation pattern for these events were extracted and compared with the results of the climatological model. This comparison will support the definition of alerts criteria when the detected disturbances exceed the climatology. Physical conditions that triggered enhanced MSTID activity were also analysed to compile an inventory of parameters that can be considered as early indicators of enhanced MSTIDs.
A mechanical insight into the continuous chatter of a fault volume
Authors: Bhat Harsha , Almakari Michelle , Kheirdast Navid , Villafuerte Carlos , Thomas Marion
Published: March 2024

In recent decades, there has been a proliferation of observations related to spatiotemporally intricate slip events occurring in fault systems. These events encompass a spectrum of transient energy releases, ranging from slow slip events to low-frequency earthquakes (LFEs) and tremors, in addition to the more familiar creep and fast ruptures. The prevailing focus in recent research has been to interpret these events by considering variations in frictional behavior along the fault plane.However, it is crucial to acknowledge the inherent geometric complexity of fault systems across multiple scales. Recent studies have illuminated the significance of incorporating a fault volume or damage zone surrounding the fault in the analysis of slip dynamics. In the context of this study, we endeavor to investigate the influence of "realistic" fault geometry on the dynamics of slip events. To achieve this, we approach the problem from three interrelated perspectives:Forward Source Modeling: We employ forward source modeling techniques to simulate and understand the behavior of slip events.
Bridging Source Modeling and Observations: We establish a connection between our source modeling and observed data by generating synthetic surface records that can be compared to actual observations.
Energy Budget Analysis: We meticulously analyze the variations in the energy budget that occur throughout the earthquake cycles to gain insights into the mechanics of slip events.
Our primary objectives include deciphering how deformation within the volume is accommodated by both the off-fault damage zone and the primary fault. Specifically, we aim to determine the proportion of the supplied moment rate that is absorbed by off-fault fractures during an earthquake cycle. Additionally, we seek to unravel how the diverse sequences of complex behavior observed on the fault plane manifest in the signals recorded by seismic stations. This entails assessing the distinct contributions of the main fault and off-fault fractures to the radiated signals detected at the monitoring stations. Lastly, we delve into the evolution of the medium's energy budget throughout the earthquake cycles and evaluate the dissipative contribution of off-fault fractures to ascertain their energetic role in the context of earthquake cycles.
Sea-level projections in recent IPCC reports: how we got here, where we are and where we’re going 
Authors: Slangen Aimée , Palmer Matthew , Camargo Carolina , Church John , Edwards Tamsin , Hermans Tim , Hewitt Helene , Garner Gregory , Gregory Jonathan , Kopp Robert , Malagon Santos Victor , van de Wal Roderik
Published: March 2024

Sea-level science has seen many recent developments in observations and modelling of the different contributions and the total mean sea-level change. Here, we focus on sea-level projections in the recent IPCC reports, and discuss (1) the evolution in IPCC projections (“how we got here”), (2) how the projections compare to observations (“where we are”) and (3) the outlook for further improving projections (“where we’re going”). We start by discussing how the model projections of 21st century sea-level change have changed from the IPCC AR5 report (2013) to SROCC (2019) and AR6 (2021), highlighting similarities and differences in the methodologies and comparing the global mean and regional projections. This shows that there is good agreement in the median values, but also highlights some differences. In addition, we discuss how the different reports included high-end projections. We then show how the AR5 projections (from 2007 onwards) compare against the observations, and find that they are highly consistent with each other. Finally, we discuss how to further improve sea-level projections in future studies.
Influence of microplastic occurrence on complex conductivity of river sediments
Authors: Li Shuai , Xu Mingsa , Peng Yumeng , Hu Xiangyun
Published: March 2024

This study utilized an improved sand column experimental setup to investigate the effects of microplastic on Yangtze River bank sediments. The experiments conducted included Darcy experiments, electrokinetic experiments, and wettability experiments, together for the same sample. By varying the particle size of the microplastics in the samples, we were able to observe different response of the electrical properties as well as hydrogeophysical parameters in the samples.Results show that increasing the mass fraction of mixed microplastics generally resulted in a significant decrease in sample electrical conductivity associated with an increase in permeability. These were expected to be due to the weak conductivity and strong hydrophobic properties of plastic particles, as well as the small adhesive forces between particles, which increased the pore space of the sediments and ultimately increased permeability. However, an anomalous increase trend was observed when decreasing the particle size of the mixed microplastics. Under this condition, increasing the concentration of same size plastic particles enhanced the electrical conductivity of the sediment sample. This anomaly phenomenon was reflected in both permeability and wettability, resulting in a decrease in sample permeability and a significant increase in sample hydrophobicity. Our observations using optical microscopy revealed two types of microplastic distribution in the sediments: one case was that microplastic particles were distributed within sediment pores and they did not touch each other, the other was that they were adsorbed onto sediment particle surfaces. We hypothesized that changes in the existence form of microplastics altered the double-layer structure of sediments, ultimately changing their hydrogeophysical parameters. This work has significance and relevance for electromagnetic-based characterization of microplastic-filled porous materials; for example, estimation of microplastic abundance in sediments.
A comparative study to analyze O and H water isotopes in organic enriched solutions
Authors: Hissler Christophe , Klaus Julian , Barnich François , Guignard Cédric , Louis Loïc , Zuecco Giulia , Angeli Nicolas
Published: March 2024

The stable isotopes of hydrogen and oxygen of the water molecule are widely used in ecohydrological-process studies to understand water uptake, redistribution by plants or to partition evaporation and transpiration. In this regard, within the last decade, the demands for a high spatio-temporal resolution of stable isotope data from xylem water has risen to better understand the water interactions between the Critical Zone compartments.The arrival of isotope ratio infrared spectroscopy (IRIS) for analysing stable water isotopes based on the different adsorption spectra of water molecules with different isotopic composition allowed much faster sampling processing, in-situ measurements in the field, and lower costs per sample. Currently two IRIS instruments are available on the market with measurement technology based on i) off-axis integrated cavity output spectroscopy (OA-ICOS) and ii) wavelength scanned cavity ring-down spectroscopy (WS-CRDS). However, IRIS measurements of water samples can be seriously compromised by interference of some specific organic compounds in the sample with the absorption spectrum of water isotopologues. The impact of contamination issue by organic compounds on the IRIS measured isotopic composition has led to a range of measures to support usability of IRIS instruments in ecohydrological studies.Until recently isotope ratio mass spectrometry (IRMS) was the standard in isotope hydrology studies and it is still considered as the reference in ecohydrology to mitigate the effects of organic contamination. However, IRMS analysis of water samples include the oxygen and hydrogen isotopes of organic compounds that are present in the water before entering the furnace of the spectrometer. Those compounds are burned at the same time as the oxygen and hydrogen of the water molecule and can dissipate together with those resulting in joint signal detection in the mass spectrometer analysis. This contribution to the measured oxygen and hydrogen isotopic composition from the organic compounds has the potential to compromise the IRMS results depending on the concentration, species, and the isotopic composition of the organic compounds present in the water sample.In this study, we assess the type and concentration of organic compounds in extracted xylem water and evaluate their impact on stable water isotope analysis with IRMS and IRIS. Our working hypothesis is that samples that are currently analysed in ecohydrology, such as xylem samples heavily enriched in organic compounds, decrease more the analytical precision of IRMS than that of IRIS. We perform an intercomparison study between IRMS and two IRIS instruments with different configurations (with and without combustion module; old and new catalyst) on water without organic compounds, water spiked using different organic molecules (glucose, ethanol, methanol) and beech sap samples.
Using ocean chemical budgets and groundwater flow models to quantify SGD individual component fluxes
Authors: Kiro Yael , Levy Yehud
Published: March 2024

Coastal aquifers encompass a variety of flow patterns, with circulating seawater being a prominent phenomenon driven by diverse mechanisms of varying spatial and temporal scales. Understanding the volume of seawater circulation in aquifers is of great interest due to water-rock interactions and consequent modification of seawater composition. While the influence of circulating seawater on ocean biogeochemistry and ecology is well recognized, quantifying its actual effect is challenging due to the involvement of multiple mechanisms.In this study, we employed element and isotope ocean budgets and groundwater flow modeling to quantify fluxes through specific mechanisms, enabling us to determine solute fluxes from coastal aquifers into the sea. Our budgets included all known ocean sources and sinks, such as river fluxes, mid-ocean ridge hydrothermal circulation, basalt weathering, and diffusive fluxes. We used major element budgets and δ26Mg and 87Sr/86Sr budgets to constrain the long-term SGD flux. Our sensitivity tests included steady-state conditions and scenarios where the hydrothermal fluxes and rivers were over or underestimated, and precipitation of carbonates was over-estimated. We found the steady-state, underestimation of both hydrothermal and river fluxes, and overestimation of carbonate fluxes reasonable scenarios.Our findings, using groundwater flow models sensitivity tests and geospatial databases, reveal that benthic wave-driven circulation contributes the largest volume of circulating seawater, while other mechanisms such as nearshore circulation, tidal pumping, and density-driven circulation are 2-3 orders of magnitude smaller. However, the short duration (minutes) of water-rock interaction under the wave-driven circulation limits its potential to modify seawater. Long-term density-dependent circulation emerges as the most significant mechanism influencing ocean chemistry, primarily due to its extended time scale of water-rock interaction. The prevailing water-rock interaction process in coastal aquifers is identified as ion exchange, wherein circulating seawater returning to the sea becomes enriched in calcium and depleted in potassium and sodium. The annual volume of seawater circulating through the long-term process is calculated to be approximately 1000-2000 km3/y, resulting in calcium and potassium fluxes of 17 ± 6 and -3.36 ± 1.6 Tmol/y, respectively. Notably, these fluxes are of the same magnitude as solute fluxes from rivers.
Tabular Reinforcement learning for Robust, Explainable CropRotation Policies Matching Deep Reinforcement LearningPerformance
Authors: Goldenits Georg , Mallinger Kevin , Neubauer Thomas , Weippl Edgar
Published: March 2024

AbstractDigital Twins are becoming an increasingly researched area in agriculture due to the pressure on food security caused by growing population numbers and climate change. They provide a necessary push towards more efficient and sustainable agricultural methods to secure and increase crop yields.Digital Twins often use Machine Learning, and more recently, deep learning methods in their architecture to process data and predict future outcomes based on input data. However, concerns about the trustworthiness of the output from deep learning models persist due to the lack of clarity regarding the reasoning behind their outputs.In our work, we have developed crop rotation policies using explainable tabular reinforcement learning techniques. We have compared these policies to those generated by a deep Q-learning approach, using both five-step and seven-step rotations. The aim of the rotations is to maximise crop yields while maintaining a healthy nitrogen level in the soil and adhering to established planting rules. Crop yields may vary due to external factors such as weather patterns, so perturbations were added to the reward signal to account for these influences. The deployed explainable tabular reinforcement learning methods perform similarly to the deep Q-learning approach in terms of collected reward when the rewards are not perturbed. However, in the perturbed reward setting, robust tabular reinforcement learning methods outperform the deep learning approach while maintaining interpretable policies. By consulting with farmers and crop rotation experts, we demonstrate that the derived policies are reasonable and that the use of interpretable reinforcement learning has increased confidence in the resulting policies, thereby increasing the likelihood that farmers will adopt the suggested policies.Keywords: Digital Twin, Reinforcement Learning, Explainable AI, Agriculture, Crop Rotation Planning, Climate Change, Food Security
Implementation of a newly developed Photonic Meta-Concrete into the COSMO-CLM model to estimate the impact on the urban heat island: a case study of Flanders, Belgium
Authors: Adams Nick , Neirynck Jérôme , Borgers Ruben , Van Lipzig Nicole
Published: March 2024

Radiative cooling (RC) materials gained interest over the past decades, as these can help mitigating the urban heat island effect, fighting climate change and reducing the cooling demand for buildings. Their altered photonic properties, albedo and emissivity, enable these materials to cool down below ambient temperature and radiate heat in the atmospheric spectral window (8-13 µm), effectively releasing heat into space. Current RC materials typically consist of thin layers of metal and polymer, manufactured through energy-intensive and costly manufacturing processes. The Horizon 2020 project ‘MIRACLE’ is developing a new innovative radiative cooling material, that for the first time, is based on conventional concrete.This study quantifies the effect of the Photonic Meta Concrete (PMC) on the climate of the highly urbanized region of Flanders, Belgium (13600 km²). Modelling such a large area allows to explore the impact on the urban heat island across multiple cities with diverse geometrical and geographical properties. More specifically, this study assesses the urban heat island effect of selected cities during a heatwave in August of 2019, comparing scenarios with and without the implementation of PMC in the built environment. The COSMO-CLM regional climate model, utilizing the TERRA-URB urban-canopy land-surface scheme, is employed for this assessment. Integration of the PMC’s photonic properties, i.e. the specific emissivity and albedo, into the urban canopy scheme is achieved by adapting the land surface parameters using the Semi-empirical Urban CanopY parametrization (SURY). Comparisons are made between scenarios incorporating specific albedo of the PMC, specific emissivity of the PMC or both against a baseline scenario without the PMC implementation. These comparisons aim to estimate the mitigation potential offered by this innovative material.Initial findings suggest that the PMC shows promising potential for lowering city temperatures, with the albedo being identified as the primary factor in combating the urban heat island effect. In Brussels, surface temperatures drop by as much as eight degrees, while temperatures at a height of two meters decrease by up to two degrees
Feedback mechanisms controlling Antarctic glacial cycle dynamics simulated with a coupled ice sheet–solid Earth model
Authors: Albrecht Torsten , Bagge Meike , Klemann Volker
Published: March 2024

The dynamics of the ice sheets on glacial-interglacial time scales are highly controlled by interactions with the solid Earth, i.e., glacial isostatic adjustment (GIA). Particularly at marine ice sheets, competing feedback mechanisms govern the migration of the ice sheet’s grounding line and hence the ice sheet stability.In this study, we run coupled ice sheet–solid Earth simulations over the last two glacial cycles. For the ice sheet dynamics we apply the Parallel Ice Sheet Model PISM and for the load response of the solid Earth we use the three-dimensional viscoelastic Earth in view of sea-level and vertical displacement changes we apply the Viscoelastic Lithosphere and Mantle Model VILMA.With our coupling setup we evaluate the relevance of feedback mechanisms for the glaciation anddeglaciation phases in Antarctica considering different 3D Earth structures resulting in a range of load-response time scales. For rather long time scales, in a glacial climate associated with far-field sea level low stand, we find grounding line advance up to the edge of the continental shelf mainly in West Antarctica, dominated by a self-amplifying GIA feedback, which we call the ‘forebulge feedback’. For the much shorter time scale of deglaciation, dominated by the Marine Ice Sheet Instability, our simulations suggest that the stabilizing GIA feedback can significantly slow-down grounding line retreat in the Ross sector, which is dominated by a very weak Earth structure (i.e. low mantle viscosity and thin lithosphere).The described coupled framework, PISM-VILMA, allows for defining restart states to which to run multiple sensitivity simulations. It can be easily implemented in Earth System Models (ESMs) and provides the tools to gain a better understanding of ice sheet stability on glacial time scales as wellas in a warmer future climate.
Lake breeze characteristics and high-resolution cloud products retrieved by wind profile radar in Nam Co, TP
Authors: Sun Lijun , Wang Binbin , Ma Yaoming , Shi Xingdong
Published: March 2024

Lake breeze systems can contribute substantially to the local climatic and hydrological variability by altering atmospheric boundary layer processes, such as the advection and convection of air flow, exchanges of turbulent latent and sensible heat fluxes, and the spatial heterogeneity of clouds and precipitation formation. However, the limited in situ measurements and the low spatiotemporal resolution of satellite products and reanalysis data has hindered our comprehensive and complete assessment of local atmospheric recirculation flows (i.e. lake breeze) over lake basins of the Tibetan Plateau. Here, based on the high-resolution wind profile radar measurements at Nam Co Station for one year (2022.6-2023.5), we analyzed the characteristics of lake breeze and clouds, and evaluated four popular reanalysis wind products (ERA5, MERRA-2, CSFv2, JRA55). The results showed that (1) The lake breeze had annual occurrence frequency of 29%, annual mean speed of 3.6 m/s, average onset 2-5 h after sunrise, annual mean duration of 4.8 h, and average vertical development height ranging from 300 m to 600 m. The lake breeze developed vigorously when the background wind was less than 6 m/s. Increased frequency, earlier onset time, and longer duration during May-September indicated lake breeze evident seasonal variation. (2) The diurnal variation of cloud frequency fluctuated around 0.5 from May-September, and the cloud frequency at night was higher than that during the day from October to April. (3) The wind direction deviation of 550hPa reanalysis data was large (RMSE > 60°, MAE: 43-48°), the wind field of 500hPa and above were in good agreement with the radar, and ERA5 had superiority.Keywords: Tibetan Plateau, Nam Co, lake breeze, cloud base height, reanalysis data evaluation.
Improvements in the spread-skill relationship of precipitation in a convective-scale ensemble through blending
Authors: Gainford Adam
Published: March 2024

Convective-scale ensembles are routinely used in operational centres around the world to produce probabilistic precipitation forecasts, but a lack of spread between members is providing forecasts that are frequently overconfident. This deficiency can be corrected by increasing spread, increasing forecast accuracy or both. A recent development in the Met Office forecasting system is the inclusion of Large-Scale Blending (LSB) in the convective-scale data assimilation scheme. This method aims to reduce the synoptic-scale forecast error in the analysis by reducing the influence of the convective-scale data assimilation at scales that are too large to be constrained by the limited domain. These scales are instead initialised using output from the global data assimilation scheme, which we expect to reduce the forecast error and, thus, improve the spread-skill relationship. In this study, we have quantified the impact of LSB on the spread-skill relationship of hourly precipitation accumulations by comparing forecast ensembles with and without LSB over a 17-day summer trial period. This trial found modest but significant improvements to the spread-skill relationship as calculated using metrics based on the Fractions Skill Score. Skill is improved for a lower precipitation centile by an average of 0.56% at the largest scales, but a corresponding degradation of spread limits the overall correction. The spread-skill disparity is reduced the most in the higher centiles due to a more muted spread response, with significant reductions of up to 0.40% obtained at larger scales. Case study analysis using a novel extension of the Localised Fractions Skill Score demonstrates how spread-skill improvements transfer to smaller-scale features, not just the scales that have been blended. There are promising signs that further spread-skill improvements can be made by implementing LSB more fully within the ensemble.
Temporal clustering of rainfall for landslides detection
Authors: Banfi Fabiola , Bevacqua Emanuele , Rivoire Pauline , Oliveira Sérgio C. , Pinto Joaquim G. , Ramos Alexandre M. , De Michele Carlo
Published: March 2024

Landslides are impactful and complex natural hazards, causing important damages in vulnerable areas. They can be related to several pre-existing conditions and triggering factors. The former are variables that do not directly cause the event but that increase its likelihood in the presence of a triggering variable. Example of the former are the slope or the aspect, of the latter precipitation, earthquakes, snowmelt, or human disturbances. Among the triggering factors the most important is rainfall. Usually deep-seated movement, characterized by a slip surface deeper than 1.5 m, are related to repeated moderate precipitation episodes while shallow landslides, characterized by a slip surface less deep than 1.5 m, to single and more intense episodes. Landslide detection is usually performed with the use of precipitation thresholds, either process-based or empirical ones. Here we introduce a new methodology to detect landslides based on temporal clustering of precipitation. Temporal clustering is a particular typology of compound event falling inside the category of temporal compounding events and it is defined as the occurrence of multiple events of the same type in close succession. The new method is compared with the use of empirical rainfall threhsolds considering as case study two landslide inventories in the Lisbon region, Portugal. The method shows a better sensitivity with respect to empirical rainfall thresholds and a performance in terms of precision variable dependending on the site. In general, the detection of deep landslides is better than of shallow landslide. The method requires only precipitation data and the selection of a precipitation quantile to identify events and it could help to improve the detection of rainfall-triggered landslides.
On the Equilibrium State of the Beach Profile Based on the Concept of Wave Phase Potential and Its Changes due to Sea Level Rise
Authors: Lee Jung Lyul
Published: March 2024

Despite much academic progress and groundbreaking changes in thinking, research results on how sandy terrain forms its current profile shape and how it evolves in the short term based on the equilibrium profile state are minimal. In this study, based on the concept of wave phase potential, which was devised based on the equation of equilibrium beach profile in the surf zone, it is shown which type of beach profile is in equilibrium in the inflow of flat waves. In order to interpret the erosion problem caused by sea level rise on the basis of this concept, we will show how the beach profile responds to sea level rise. As a representative result, the beach retreat width due to sea level rise is given as a function of the dominant wave period and the beach scale factor (a factor obtainable from the sand grain size) as well as the sea level rise. This equation is compared to Bruun's proposal and also discusses the constraints in applying Bruun formula. The results of this study can provide a scientific basis for predicting how a seabed topography composed of sand can be formed or to reverse estimate the wave incident condition from the current landform and seabed conditions, as long as the inflow wave data and the sampled sand grain size data are available. Moreover, it shows how devastating the inundation erosion caused by sea level rise can be. It is time to judge how urgent it is to secure a coastal buffer zone behind this, and to hasten technical and policy responses to mitigate the damage caused by it. As an example of application, the sea level rise trend for the coast of the Korean Peninsula and the inundation erosion predicted for 2050, 2070 and 2100 for 350 beaches of the Korean Peninsula will be presented.
A stochastic framework for rainfall intensity-timescale-return period relationships regionalized over Greece 
Authors: Iliopoulou Theano , Koutsoyiannis Demetris , Malamos Nikolaos , Koukouvinos Antonis , Dimitriadis Panayiotis , Mamassis Nikos , Tepetidis Nikos , Markantonis David
Published: March 2024

We develop a regionalization framework for rainfall intensity-timescale-return period relationships that is implemented across the Greek territory. The methodology for single-site estimation is based on a stochastic framework for multi-scale rainfall intensity modeling. Five parameters are first independently fitted for each site, and the resulting parameter variability is explored in terms of uncertainty and spatial variability patterns. Two parameters, the tail-index and a timescale parameter, are identified as constant in space and estimated using data pooling techniques. The remaining three parameters are regionalized across Greece using a combination of spatial interpolation and smoothing techniques, which are evaluated using cross-validation in a multi-model framework.
Novel source localization method from observed peak emissions in time series using LPDM transfer functions
Authors: Klappenbach Friedrich , Chen Jia , Cohen Ronald C. , Franklin Jonathan , Jones Taylor , Makowski Moritz , Wofsy Seven
Published: March 2024

We developed a novel method to estimate from an observations-time series the upwind distance as well as the emission strength of an unknown source, which releases a gas into the atmosphere (top-down). For this purpose, we used LPDM-modeled particle trajectories to infer the transfer function of the source region. The transfer function that matches the observed enhancement best, identifies the potential source region. In a second step, we infer the source strength using the particle ensemble.We developed this method with a data set obtained during a six-week campaign in the San Francisco Bay Area. Aim was, to infer greenhouse gas emissions, specifically carbon dioxide and methane, from total column abundances.At the UC-Berkeley site, one particular instrument recorded a strictly periodic peak-enhancement of approximately 10ppb methane within a consecutive 12-minute interval. Co-emitted species showed no correlation with this pattern. Therefore, we assumed a singular, point, and puff-emitting source of methane.Due to favorable meteorological conditions, we were able to analyze a total of 14 peaks during a three-hour time-span in the forenoon. We estimated the average emission strength during the emission period to be 1.8+/-0.5 g(CH4)/s (equivalent to 6.48+/-1.80 kg/hr). Although we were unable to identify the source in the field, we concluded that methane ventilation from the natural gas supply, a so-called blow-down, could be a plausible explanation.