bluuebunny/crossref_metadata_2025 huggingface dataset:
Drought and flood episodes during the 19th Century in Catalonia (NE Iberian Peninsula) 
Authors: Pino David , Barriendos Josep , Barriendos Mariano , Balasch Carles , Tuset Jordi , Andreu-Hayles Laia
Published: March 2024

The current context of climate change is leading to an increase in hydroclimate variability in the Mediterranean region. This situation is resulting in more frequent and longer dry periods but also in an increase of torrential rainfall events. Current situation justifies the study of the behaviour of droughts and floods from an integrated long-term perspective.This study aims to study droughts, floods and their interaction during the 19th century in Catalonia using historical and administrative documentary sources. The 19th century corresponds to a climatic period of transition between the Little Ice Age and the current climatic period that includes the appearance of different climatic forcing factors such as solar minimums and extraordinary volcanic eruptions.In Catalonia 19th century stands out for having some of the most important droughts recorded in the instrumental series of Barcelona (1812-1825), along with experiencing some notable catastrophic flood events. Administrative documentary data allowed us to study at daily resolution flood episodes such as in August 1842, May 1853, September 1874 and January 1898, together with the duration and frequency of drought episodes. Complementarily, in order to characterize the atmospheric general patterns during these episodes, we also generated daily barometric synoptic maps using old instrumental pressure data from different points of Europe. This approach provided the identification of different atmospheric anomalies driving these extreme hydrometeorological events.
Assessing the impact of forest fires on human health in Europe
Authors: Chowdhury Sourangsu , Hänninen Risto , Sofiev Mikhail , Aunan Kristin
Published: March 2024

Long term exposure to ambient PM2.5 (particulate matter less than 2.5 µm in diameter) is associated with multiple health outcomes, including morbidity and mortality from respiratory, cardiovascular and cerebrovascular diseases, among other non communicable diseases and is the largest environmental health risk in Europe. While much attention globally has centered on reducing anthropogenic sources of ambient PM2.5 and other air pollutants, the significance of forest fires, capable of inducing extreme air pollution, was largely underestimated until recently, lacking credible mitigation strategies. Forest fires release various hazardous pollutants like black carbon and organic aerosols, potentially posing greater health risks compared to other sources of pollution. Our study delves into the escalating importance of forest fires as contributors to PM2.5 exposure in Europe across a thirty-year period (1990-2019), utilizing simulations from a global meso-scale dispersion model. Additionally, we evaluate the health impact resulting from PM2.5 due to forest fires, examining how this burden has changed over three decades in relation to shifts in mortality rates, demographics, forest fires, and PM2.5 exposure. Our calculations indicate a decrease in the additional number of deaths caused by exposure to ambient PM2.5 throughout Europe, dropping by 10,000 deaths annually. This decline is observed from 0.57 million deaths (with 95% confidence intervals between 0.44 - 0.75 million) in 1990 to 0.28 million deaths (ranging from 0.19 – 0.42 million) within the specified time frame.Through our sensitivity analyses, wherein we considered PM2.5 from forest fires as more hazardous compared to other sources, we found an increased relative contribution of forest fires to excess deaths. These results emphasize the urgent requirement for improved mitigation and adaptation strategies, along with the implementation of more sustainable forest management policies. 
Inter-basin comparison of deep ocean temperature change at the Eocene-Oligocene Transition
Authors: Taylor Victoria E. , Piasecki Alison M. , Bohaty Steven M. , Wilson Paul A. , Coxall Helen K. , Meckler A. Nele
Published: March 2024

The abrupt onset of large-scale Antarctic glaciation approximately 34 million years ago, at the Eocene-Oligocene Transition (EOT), was the pivot point in Cenozoic climate history between greenhouse and icehouse climate states. Our understanding of this event relies heavily on benthic foraminiferal oxygen isotope (δ18Ob) records but the paucity of independent temperature reconstructions prevents an assessment of the contributions of temperature and ice volume to the rapid δ18Ob increase which is interpreted to mark the onset of large-scale Antarctic glaciation. Here we present records of deep-sea temperature change for the EOT using clumped isotope thermometry which permits explicit temperature reconstructions independent of seawater chemistry and ice volume. Recently published benthic foraminiferal clumped isotope records from the eastern equatorial Pacific (Taylor et al. 2023) and a low-resolution long-term record from the northwest Atlantic Ocean (Meckler et al. 2022) hint at a possible thermal decoupling of these two major deep ocean basins at the EOT. To investigate this further, we present new temperature records from the Newfoundland margin in the northwest North Atlantic Ocean (IODP Exp. 342 Sites U1406 and U1411). In addition, we supplement the previously published records from the eastern equatorial Pacific (Taylor et al. 2023) with additional data (ODP Leg 199 Site 1218 and IODP Exp. 320 Sites U1334 and U1333) to better constrain the timing of the onset of deep ocean cooling relative to the onset of large-scale Antarctic glaciation. These new detailed records from both ocean basins enable an assessment of potential divergences in the evolution of deep ocean temperatures in the North Atlantic and Pacific at the EOT, and thus changes in ocean circulation prior to and/or in response to the onset of Antarctic glaciation.    Meckler, A. N. et al., (2022). Cenozoic evolution of deep ocean temperature from clumped isotope thermometry. Science, 377 (6601), 86-90.Taylor, V. E., Wilson, P. A., Bohaty, S. M., Meckler, A. N., (2023). Transient deep ocean cooling in the eastern equatorial Pacific Ocean at the Eocene-Oligocene Transition. Paleoceanography and Paleoclimatology, 38, e2023PA004650. https://doi. org/10.1029/2023PA00465
Three Fundamental Challenges to the Advancement of Stemflow Research and Its Integration into Natural Science
Authors: Van Stan John , Pinos Juan
Published: March 2024

Plant canopies divert a portion of precipitation to the base of their stems through “stemflow”, a phenomenon that influences the canopy water balance, soil microbial ecology, and intrasystem nutrient cycling. However, a comprehensive integration of stemflow into theoretical and numerical models in natural science remains limited. This perspective examines three unresolved, fundamental questions hindering this integration, spanning the canopy to the soil. First, the precise source area within the canopy that generates stemflow is undefined. Thus, we asked, “whence stemflow?” Current common assumptions equate it to the entire tree canopy, a potentially misleading simplification that could affect our interpretation of stemflow variability. Second, we asked what are the various conditions contributing to stemflow generation—beyond rain, to dew and intercepted ice melt—and could the exclusion of these volumes consequently obscure an understanding of the broader implications of stemflow? Third, we explored ”whither stemflow?” This question extends beyond how much stemflow infiltrates where, into what uptakes it and from where. Addressing these questions is constrained by current observational and analytical methods. Nevertheless, by confronting these challenges, the stemflow research community stands to make significant strides in comprehending this unique hydrological component and situating it within the broader context of natural science.
Automatic generation of topologically connected gully networks for integrated erosion control in sloping olive orchards
Authors: Peña Adolfo , González-Garrido Paula , Laguna Ana María , Gámiz Antonio Miguel
Published: March 2024

The severe erosion problems affecting large areas of olive groves on slopes in Andalusia (Spain), whose soil losses exceed 40 kg m-2an  in extreme rainfall events, require an integrated watershed management run by landowners and state or regional agencies.The most common, and most severe erosion form is gully erosion. Gullies act as preferential ways through which soli particles with adsorbed nutrients and agrochemical substances spread downslope moved by surface runoff, what implies a great water loss.During the last four years a cooperative innovation project between the University of Cordoba and two joint venture groups to (i) evaluate the extent of the soil loss in selected slopes, (ii) estimate the density and location of check-dams to intercept the water and sediment flows; (iii) design a novel type of modular dams; and (iv) complement th conservation works with new cover crops mixtures.A by-product of this project is the development of an automatic model for the spatiotemporal evolution of gully networks based on the D8 flow direction algorithm, and a network branches detection scheme to accumulate flow identifying the final outlet.This model has been successfully applied to two olive cropped slopes of Southern Spain.The innovative proposal has allowed for: (a) Generation of the DEM (Digital Elevation Model) for hydrological modeling of watersheds and determination of gullies and areas vulnerable to erosion; (b) Development of algorithms for a topologically connected network of gullies to establish the areas of origin of soil loss and sediment deposition (c) Protection and correction of ephemeral and deep gullies in pilot plots by means of dikes of modular pieces, vegetation covers in crop roads, protection of roads and vulnerable areas through native plantations, and burying of pruning remains; (d) Monitoring and follow-up of measures from LiDAR sensors on board UAVs and soil analysis before and after extreme events.These initiatives have already been successfully tested in several projects in which the University of Cordoba participates, such as the CPI INNOLIVAR project and the HIDROLIVAR Operational Group and will be implemented in new study basins where excellent results are expected due to the fragility of steep slope olive groves in very degraded soils.
Long-term P fertilizer effects on pasture soil nitrous oxide and carbon dioxide emissions
Authors: Clough Tim , Wells Naomi , Bhople Parag , Richards Karl , Bondi Giulia
Published: March 2024

Grazed pasture ecosystems are key contributors to anthropogenic nitrous oxide (N2O) emissions. Within the grazed pasture, it is the deposition of ruminant urine, from the grazing animal, that creates the hot-spot for N2O emissions. Grazed pastures also receive phosphorus (P) fertilizer to sustain plant nutrient needs. This in turn increases the soil microbial biomass pool and promotes dry matter production: this affects soil moisture dynamics and plant N uptake. How long-term P fertilizer affects N2O emissions from pasture soils in situ is poorly understood. To address this an in situ study was performed on the Winchmore long-term fertilizer trial, in New Zealand. This has run for 71 years and the pasture has not been disturbed over this time. The trial consists of replicated (n = 4) field plots (0.09 ha) receiving either 0, 17, 23, or 34 kg P ha-1 yr-1 as single superphosphate. These field plots are rotationally grazed by sheep, with stocking rate adjusted according to feed on offer. Headspace chamber bases were installed in each field plot and synthetic ruminant urine or distilled water (control) were applied. Static chambers were placed on the chamber bases during gas flux measurement. Gas measurements were taken over a 76-day period to determine N2O and CO2 fluxes. Soil inorganic-N concentrations (0 – 7.5 cm) were also followed over time, along with soil sampling for determining soil chemical characteristics. Data from this study and their interpretation will be presented to assess the effect of long-term P fertilizer on grazed pasture N2O and CO2 fluxes.
Historical and Future Climate Impacts on Hydrological Regimes: A case Study in the Upper Aral Sea Basin
Authors: Li Yukun , Guo Rui , Tian Fuqiang , Montanari Alberto
Published: March 2024

Originating in the high mountains of the western Tien Shan and Pamir, the two transboundary rivers (the Syr Darya and the Amu Darya) are the only sources of streamflow into the Aral Sea Basin, and constitute a crucial freshwater source for central Asia. Climate change is one of the giant global issues which adversely affects the water resources. Although the current water crisis in the Aral Sea Basin is largely due to human activity, the region is also strongly impacted by climate change. Upstream streamflow has important influence on downstream ecological security, environmental stability, and sustainable development. Therefore, conducting a comprehensive, long-term analysis of the impact of climate change on the hydroclimate of the Upper Aral Sea Basin is crucial in confronting freshwater challenges and solutions. However, this task still poses a significant challenge. To fill this research gap, the present study employs tree-ring based streamflow reconstruction and hydrological modeling forced by past and future hydroclimate variables to comprehensively analyze the shifts in the hydrological regime within the Upper Aral Sea Basin. We utilize data from CMIP6 and PMIP4, integrating them into hydrological models to generate detailed monthly and yearly runoff time series for the Upper Amu Darya and Upper Syr Darya, spanning from 850 to 2100. By comparing the performance of hydrological simulation and reconstruction, we aim to identify the unique strengths and weaknesses inherent in each method or dataset. This approach will significantly contribute to advancing our understanding of the hydrological dynamics in the region.
Importance of vegetation structure for predicting evapotranspiration in a tropical mosaic landscape
Authors: Kirti Raunak , Valdés-Uribe Alejandra , Hölscher Dirk
Published: March 2024

Evapotranspiration (ET) is a critical process within the hydrological cycle, susceptible to shifts due to changes in land use. In tropical forest regions, widespread transformations often result in mosaic patterns of land-use types. Our goal was to explore the importance of vegetation structure, topography, meteorology and soil for the spatial variability of ET in a tropical mosaic landscape. We used a random forest machine learning technique for spatial data, employing forward feature selection and cross-validation to prevent overfitting. Our study region is situated in north-eastern Madagascar and is mainly composed of forest fragments, vanilla agroforests, rice fields and fallow land of shifting cultivation. We used a combination of open-source data products derived from various satellite experiments. Daily ET data were retrieved from the ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS). Forest structure predictors from GEDI and PROBA-V, meteorological data from ERA5, topography from JAXA and soil data from ISRIC were obtained. The variables included in the L3 algorithm to calculate ECOSTRESS ET daily data were not included in the study to prevent bias in the models. The models achieved high accuracy for the spatial prediction of ET (R2) of 0.76 and 0.82 for different days. Besides other biophysical variables, leaf area index, tree cover and tree height were important variables in predicting ET. Our findings thereby underscore the crucial role of forest structure on ET even in complex structured tropical mosaic landscapes.
The Atacama Desert rock coast: an underrated witnesses of long-term wave erosion
Authors: Arróspide Camila , Aguilar Germán , Carrillo Hugo , Rodríguez María Pía , Regard Vincent
Published: March 2024

The Atacama Desert rock coast has allowed for the study of tectonic and climate influences on landscape construction and evolution. This rock coast features important morphologies such as: (1) the Great Coastal Cliff, which runs parallel to the coastline for almost 1000 km, reaching heights between 800 and 2000 m a.s.l.; and (2) shore platforms and staircased marine terraces, which are discontinuously recognized along the extension of the Atacama Desert coast. These morphologies, especially marine terraces, have been studied to estimate rates of uplift in order to constrain the history of the Chilean forearc deformation. However, they have received little attention about the influence of surface processes such as wave erosion on their development and preservation. Certainly, it has been largely proven that wave erosion plays an important role in the development of shore platforms and the evolution of coastal areas. Despite this, its effects on the development of shore platforms and marine terraces and, thus, the landscape construction of the Atacama Desert coast have been scarcely investigated. In this work, we developed a numerical model to understand the influence of a set of processes on the long-term landscape evolution (104-106 years) on rocky coasts. The set of processes involves relative changes in sea level due to eustatic cycles and vertical landmass movements, as well as surface processes such as wave erosion and intertidal weathering. This model allows us to estimate rates of coastal erosion and, thus, morphology development (e.g., platforms and cliffs) to provide new insights for one of the longest but underrated erosive rock coasts. The research design consisted of two stages: (1) model development and testing, and (2) model validation. The model was validated using Atacama Desert coast geomorphology, including field data and morphometric analysis from high-resolution digital elevation models. The model results and the research itself are used to understand the influence of surface processes on the evolution of rock coasts in a tectonic uplift and hyperaridity context.
Interactive decision-support for participatory water planning under multiple sources of uncertainty
Authors: Zaniolo Marta , Fletcher Sarah , Mauter Meagan
Published: March 2024

Urban water resources planning is complicated by unprecedented uncertainty in supply and demand. Real-world planning often simplifies the full range of uncertainty faced by a system into a limited set of deterministic scenarios to enhance accessibility for decision-makers and the public. However, overlooking uncertainty can expose the system to failures. The academic literature has developed tools, such as scenario analysis, to test water systems across various uncertain futures, assessing their responses to diverse drivers. Applying scenario analysis to the full set of uncertain drivers can identify system vulnerabilities, but current approaches to visualizing this information are difficult to communicate and therefore have limited practical applications. There is a lack of water planning frameworks that effectively integrate a rigorous treatment of uncertainty with accessible, user-friendly visual and interactive tools to enhance understanding and implementation for users.In this work, we develop an example of such framework for the case study of the city of Santa Barbara, CA. Santa Barbara faces multiple uncertainties in their water supply portfolio and demand, from pending state and federal regulations, to changing hydrology and water demand. The city seeks to increase their water portfolio robustness by expanding its seawater desalination plant, but must determine the expansion capacity. We introduced computational tools that enable a comprehensive assessment of uncertainty across nine uncertain drivers, identified with the help of water planners in Santa Barbara. To allow public participation in the desalination expansion decision, we develop interactive visual analytics to aid decision-makers and stakeholders in navigating complex scenario analysis outcomes. Our results quantify the tradeoffs between increased capacity and system robustness. We also categorize uncertain drivers according to their criticality and the level of control that the municipality can exert over them, for instance the city's water demand can be partially controlled through water efficiency campaigns. This work aims to enhance participation and uncertainty characterization of urban water planning efforts.
Double harmonic-series gravitational field model for bilobed small bodies: example for 67P/Churyumov-Gerasimenko
Authors: Hu Xuanyu , Andert Thomas
Published: March 2024

An increasing number of small extraterrestrial objects in the Solar System are found to have bilobed shapes, which could have resulted from the merger of two independently formed bodies. It is both natural and justified to treat the lobes separately to account for, or discern, any potential difference between them (Andert, et al., 2015). Gravity provides a crucial constraint on the interior mass distribution of the body and is among the key scientific objectives in most space missions. Most often, the gravitational field is modeled as a spherical harmonic (SH) series, whose coefficients are then used along with other constraints to interpret the interior structure.In this study, a double harmonic-series approach for the bilobed bodies is presented. Namely, a harmonic series is established for each lobe to facilitate the investigation of their interior structures separately. The focus of the analysis is on comet 67P/Churyumov-Gerasimenko, the rendezvous target of the Rosetta mission with an exemplary bilobed shape and variable gravity field (Sierks et al. 2015; Pätzold et al. 2016, 2019). We employ the ellipsoidal harmonic (EH) series, whose coefficients are fully analogous to those of the SH and whose reference surfaces fit more closely the triaxial shapes of the individual lobes (Hu 2016).We develop the double EH model for 67P via simulations and assess the model performance around the body. Additionally, we discuss the equivalence of the double EH model to the SH model as well as the conditions for direct model transformation from the latter. We revisit the physical meaning of the EH coefficients and demonstrate how their known relationship to the body's mass density moments can be leveraged to interpret different mass distributions of the comet. Importantly, there should be no restriction on the applicability of the method to other bilobed objects. ReferenceAndert, T., et al. (2015), The Gravity field of Comet 67 P/Churyumov-Gerasimenko Expressed in Bispherical Harmonics, in: AGU Fall Meeting Abstracts. pp. P31E-2109.Hu, X. (2016), The exact transformation from spherical harmonic to ellipsoidal harmonic coefficients for gravitational field modeling, Celest. Mech. & Dyn. Ast. 125, pp. 195-222, https://doi.org/10.1007/s10569-016-9678-z.Pätzold, M., et al. (2016), A homogeneous nucleus for comet 67P/Churyumov-Gerasimenko from its gravity field, Nature, vol. 530, pp. 63-65, https://doi.org/10.1038/nature16535.Pätzold, M., et al. (2019), The Nucleus of comet 67P/Churyumov-Gerasimenko - Part I: The global view - nucleus mass, mass-loss, porosity, and implications. Monthly Notices of the Royal Astronomical Society, 483, 2337–2346, https://doi.org/10.1093/mnras/sty3171.Sierks H., et al. (2015), On the nucleus structure and activity of comet 67P/Churyumov-Gerasimenko, Science, vol. 347, no. 6220, https://doi.org/10.1126/science.aaa1044.
Drought suppresses rhizosphere carbon inputs and losses with cascading effects on soil microbial communities in a pine forest
Authors: Guidi Claudia , Frey Beat , Gavazov Konstantin , Han Xingguo , Peter Martina , Mayer Mathias , Zhang Yueqi , Stierli Beat , Brunner Ivano , Hagedorn Frank
Published: March 2024

Severe drought impacts soil organic carbon (SOC) cycling. Yet, there is limited understanding of drought effects on rhizosphere C allocation and its fate in the soil, since belowground C contributes to new SOC formation while fueling soil microbial communities and SOC mineralization. Here, we quantified rhizosphere C inputs and losses in a 17-year long irrigation experiment in a dry Scots pine forest using 13C-enriched soil ingrowth bags with different mesh sizes. Fungal and bacterial communities inside the ingrowth bags and in adjacent soils were analyzed by Illumina MiSeq sequencing.After two years, net new SOC accumulation was 5 times greater in root-accessible vs root-exclusion bags (1000- vs 20-μm mesh). Irrigation stimulated new SOC formation in the first year as compared to natural drought both in root-accessible (+26%) and root-exclusion bags (+47%). Losses of “old” 13C-enriched SOC increased under irrigation in root-accessible (+88%) and root-exclusion bags (+32%), resulting in an overall balanced effect of irrigation on SOC. After two years, irrigation showed a limited effect on net new SOC formation both in root-accessible and root-exclusion bags despite a 70% greater root ingrowth under irrigation. We attribute the lacking irrigation effect on rhizosphere-derived SOC to higher respiratory losses of new soil C, which is in line with +55% old C losses by irrigation in root-accessible bags after two years. These findings indicate a faster C cycling in the rhizosphere under irrigation with enhanced C inputs, which were however rapidly mineralized, resulting in negligible net effects. The increased belowground C allocation and increased C turnover in the rhizosphere under irrigation were paralleled by shifts in fungal and bacterial communities in ingrowth bags as well as in adjacent soils. Fungal and bacterial community structures were also shaped by the presence of roots in the bags.Overall, our results in this long-term irrigation experiment imply that naturally dry conditions slow SOC cycling, suppressing both rhizosphere C inputs and losses. The reduced supply of belowground C leads to cascading effects on soil microbial community composition under drought.
Beyond the Peak: What we know and don't know about temperature overshoot
Authors: Schleussner Carl-Friedrich
Published: March 2024

Global emission reduction efforts continue to be insufficient to meet the temperature goal of the Paris Agreement. This makes the systematic exploration of so-called overshoot pathways that draw temperatures back down to safer levels in the long term a priority for science and policy. I will present major insights from the Horizon 2020 PROVIDE project on overshoot pathways. We find that global and regional climate change in a post-overshoot world would be substantially different from a world that avoided overshoot, bearing profound implications for adaptation needs. Irrespective of the peak warming, we find that achieving declining global temperature remains critical for limiting long-term climate risks including sea-level rise and cryosphere changes. Reversal of warming by deploying carbon dioxide removal (CDR) at scale, however, is not guaranteed. In addition to uncertain technical and sustainability limitations of CDR, we find that a preventive CDR capacity of several hundred gigatonnes might be desirable to hedge against strong Earth system feedbacks that amplify warming. Aiming for temperature decline is thus not a robust strategy to achieve a climate objective, but rather one part of a broader approach towards managing long-term climate risks. It is no replacement for stringent near-term emission reductions to limit risks at peak warming in the first place.
Improved GNSS receiver bias estimation using a neural-network based total electron content model
Authors: Hoque Mainul , Adolfs Marjolijn , Salamanca Luisa Riaño
Published: March 2024

With the availability of fast computing machines, as well as the advancement of machine learning techniques and Big Data algorithms, the development of a more sophisticated total electron content (TEC) model featuring large scale ionospheric irregularities and anomalies is possible. We recently developed a fully connected neural network model trained with Global Ionospheric Maps (GIMs) data from the last two solar cycles. The model can successfully reconstruct ionospheric features that are not always visible such as Nighttime Winter Anomaly (NWA) which is only visible in the Northern Hemisphere at the American sector and in the Southern Hemisphere at the Asian longitude sector during low solar activity, winter and local night-time conditions. The NN based TEC model inherits also other features such as the distribution of Mid-latitude Ionospheric Trough (MIT) and the longitudinal variation of the Equatorial Ionization Anomaly (EIA) features. Being motivated from the performance of the NN based TEC model in ionosphere reconstruction we applied the model for differential code bias (DCB) estimation for a network of ground GNSS receivers. The investigation shows that the receiver DCBs can be accurately computed by the NN-based TEC model. The obtained accuracies are comparable to those obtained by the conventional method of DCB estimation by fitting GNSS TEC data to the ionospheric basis function represented by spherical harmonics or other approaches. It is expected that the application of NN based TEC model for GNSS receiver bias estimation will simplify the operational procedures for near real-time ionosphere monitoring without losing its accuracy.
A unifying moist shallow water framework and test cases for moist shallow water models
Authors: Hartney Nell , Bendall Thomas
Published: March 2024

The rotating shallow water equations are widely used in the development of weather and climate models. They are a much simpler equation set than the full 3D atmospheric equations and so are computationally cheap, but they still retain many pertinent features of atmospheric dynamics. The usual shallow water equations model a ‘dry’ atmosphere and so neglect moist processes and moisture effects. Including moisture in the shallow water system not only extends the modelling potential of the equations, but also introduces numerical complexities that are of interest in the development of time-stepping schemes. These include features such as new timescales related to moist physics processes, discontinuities introduced by the notion of boundaries between ‘precipitating’ and ‘non-precipitating’ regions, and how the addition of moisture affects the ideas of balance and conservation in the equations. In this way the moist shallow water equations provide a simplified equation set for exploring physics-dynamics coupling and how this coupling is handled by different time steppers.This talk will discuss our implementation of a flexible, unifying moist shallow water model that encompasses three different approaches to moist shallow water modelling. Our implementation is in the dynamical core toolkit Gusto, which follows a compatible finite element approach like that of the next-generation UK Met Office model. We will demonstrate some simple moist shallow water test cases using each of the three approaches with our unifying formulation in Gusto, and describe progress towards running tests with more complex dynamics to investigate questions about time-stepping with physics. 
TRACE: An approach to detect, track and monitor large floating marine litter in our seas
Authors: Weiß Tobias , Bochow Mathias
Published: March 2024

Marine debris is a severe environmental problem. It originates from many sources and causes a wide spectrum of environmental, economic, safety, health and cultural impacts. Millions of tonnes enter the oceans every year and tackling the issue is gaining momentum at all levels.Our project presents an approach to detect and track floating marine debris such as lost fishing nets, debris aggregations or patches based on high-resolution remote sensing time series, machine learning, and ocean current modeling. The goal is to obtain more reliable data regarding quantity, position, material properties and sources of litter as well as to address the lack of understanding of floating debris behavior in the open sea due to the limited monitoring capabilities (Garaba and Dierssen, 2018). In order to achieve this goal, a convolutional neural network was trained with a hand-labeled dataset of objects floating on the sea surface extracted from Planet satellite imagery, to learn the spatial characteristics of these objects. A software pipeline has been developed to automatically retrieve, process and analyze large amounts of satellite images and enable continuous monitoring. As identifying floating objects in the marine environment from space remains a challenging and difficult task and ground truthing is near to impossible, we further apply a mechanism to find matching objects on time series of satellite images using an ocean current model as well as different image processing techniques.
Justice and urban transformation in light of accelerating climate change 
Authors: Haustein Karsten , Zacher Hannes , Liebal Katja , Eichholz Marie , Mühlhaus Ulrike
Published: March 2024

Climate change adaptation in urban spaces will only be successful if societal actors from science, politics and public find common ground, and join forces on a local level. One of the sectors that is notoriously difficult to transform in a sustainable way is transportation, and linked to it the way we design our cities. Bike infrastructure is almost universally under-developed (apart from notable exceptions such as Utrecht, NL, or Copenhagen, DK), putting marginalised people at a massive disadvantage in that they cannot freely choose which mode of transport to use. The structural privilege for motorists in virtually all post-war western societies is so prevalent, that even mentioning of the shear existence of those privileges is considered offensive and met with huge outcry and media frenzy in support of the status quo.So how to address the issue, given the fact that a host of transformative steps are undoubtedly required to make urban spaces future proof? How are we raising awareness to the fact that the externalised costs of excessive car use in cities are vastly underappreciated - be it health related costs due to noise and air pollution, accidents, lack of exercise; environmental costs due to carbon emissions; infrastructural investments; or the lack of greenery due to parked cars, and so on? In short, how can we change the conversation such that justice and visionary thinking (rather than fear) become front and center of the discourse?We show how tailored science communication can help to expose preconceived notions and thus reduce conflict between various actors. The strategy is based on solid evidence, which highlights the hidden costs of currently privileged modes of transport. Also, it demonstrates why certain arguments in support of the status quo are deeply flawed. Using expertise from colleagues in the social sciences (organizational psychology), we aim at understanding why decision makers act so hesitantly. Ultimately, a list of guiding principles when it comes to constructive dialogue - and identifying bad faith actors - will be developed (with the help of experienced societal actors) and disseminated amongst decision makers but also colleagues in disciplines with similar levels of public controversy. First results are presented at EGU’24.
The continuous growth of newly formed particles in urban environments
Authors: Du Wei , Zha Qiaozhi , Cai Jing , Yan Chao , Zheng Feixue , Guo Yishuo , Kokkonen Tom , Liu Yongchun , Kerminen Veli-Matti , Kulmala Markku
Published: March 2024

New particle formation events (NPF) are observed to take place in all environments, including megacities where the concentrations of pre-existing particles acting as sink are exceptionally high. NPF produces high number concentration of small particles, which can act as seed particles suitable for the accumulation of particle mass after their subsequent growth. However, the reason of the frequently observed NPF in urban environments is still unclear, and the contribution of NPF and subsequent growth to air pollution is still controversial.To improve the understanding of the link between air pollution and NPF, comprehensive observations, including gaseous precursors, size distributions and chemical compositions of atmospheric aerosols, as well as meteorological conditions, were conducted in the west campus of Beijing University of Chemical and Technology (BUCT, 39o 56’31” N, 116o17’50” E), near the West Third Ring Road of Beijing, China. We also performed simultaneous measurements of aerosol composition and particle number size distributions at ground level and at 260 m based on the 325 m Beijing meteorological tower.We divided NPF events into two types based on whether the newly formed particles grow continuously or not. By comparing the meteorological conditions, gaseous precursors, and chemical composition between these two types, we investigated the conditions favour the continuous growth of new formed particles. Our results also showed that the continuous particle growth could contribute to the formation of haze. Due to the stronger emission of gaseous precursors near ground coupled with the less effective boundary layer mixing, particles originating from NPF continue to grow at ground level while their mean diameter remains relatively stable at a higher altitude, resulting in the more severe haze pollution at ground level than at high altitude.
A Multi-Scale Scheme for Simulating Subsurface Dynamics in Land Surface Models using HydroBlocks
Authors: Guyumus Daniel , Torres-Rojas Laura , Bacelar Luiz , Chaney Nathaniel
Published: March 2024

Over recent years, considerable advances have been made in Land Surface Models (LSM) to enhance the representation of small-scale heterogeneity while maintaining reasonable computational efficiency. Such is the case of HydroBlocks, which employs fine-scale clustering to define Hydrologic Response Units (HRUs) or tiles as its core modeling element. These innovations have facilitated a better representation of water and energy balances over large-scale domains by capturing local dynamics and their signature over continental processes.While the benefits of these advances are substantial, there is still a growing need to understand surface and subsurface dynamics under these novel approaches. In our current study, we propose a novel multi-scale scheme designed to capture subsurface interactions within an LSM. This approach builds upon the abstraction introduced in HydroBlocks and addresses the lateral contributions of soil columns for local, intermediate, and regional subsurface flows. Importantly, this is achieved without compromising the computational efficiency of the already efficient HydroBlocks model. Our approach enables us to capture complex fine-scale interactions between surface and subsurface hydrological processes over continental extents, potentially providing insights that traditional models cannot achieve.To implement this, we decompose the domain into regional units and compute the subsurface flux exchange, efficiently updating the one-dimensional vertical solution of Richard’s equation within the LSM. A convergence analysis is performed by comparing the efficiency of our framework to that of the quasi-fully distributed solution. The methodology has been tested within a 1.0°x1.0° domain in the United States to evaluate its performance. The inclusion of intermediate and regional groundwater representation led to significant shifts in soil moisture redistribution and streamflow patterns. Notably, we uncover regional water flow patterns from ridges to valleys, often underrepresented in the traditional model. Additionally, we explore the impact of spatial scale on water redistribution, offering profound insights into the uncertainties associated with groundwater structure and its influence on surface fluxes.Our findings reveal that the multi-scale scheme converges towards a quasi-fully distributed solution for the LSM HydroBlocks emphasizing the efficacy of our method in achieving a comprehensive representation of subsurface dynamics while maintaining computational cost.
Rhizosphere microbial activities in response to combined effects of drought and microplastic 
Authors: Feizi Ali , Hoang Duyen T.T. , Razavi Bahar S. , Spielvogel Sandra
Published: March 2024

The human’s well-being is challenged by various global issues such as environmental pollution and climate change. While plastic waste, particularly microplastic, is an emerging environmental pollution, drought becomes a more frequent natural hazard to cropping system.Two hypotheses were proposed in this research as (i) drought is more dominated as compared to microplastic existence regulating microbial activities; (ii) the effects of microplastic on enzyme activities and distribution are enzyme specific and depends on microplastic types. Zymography was acquired to demonstrate the distribution of β-glucosidase (GLU) and acid phosphatase (APT) within soybean rhizosphere amended with either biodegradable microplastics or nondegradable microplastics. In addition, enzyme activities of GLU, APT, leucine aminopeptidase (LEU), and microbial biomass phosphorus (MBP) were assayed to prove the hypotheses. Five-time lower hotspot percentage in dry soil than moist soil regardless of microplastic types implied an overwhelming impacts of water stress as compared to microplastics on the microbial degradation of soil organic matter in the plant-soil ecosystem. A shortened rhizosphere extent was found in microplastic treatments also demonstrated its negative influence on rooted microbial activities. In conclusion, the co-influence of two distinguished abiotic factors should increase the complexity of plant-microbe association and unpredicted regulation of nutrient and C flux in the crop land.Keywords: rhizosphere, enzyme activities, microbial biomass, drought, zymography
Formation and modulation of ice clouds by gravity waves
Authors: Dolaptchiev Stamen , Achatz Ulrich
Published: March 2024

Observational and modeling studies suggest that gravity waves (GW) canhave a substantial impact on the microphysical properties of iceclouds and their life cycle. However, the effects of GW on ice cloudsare only crudely parameterized in current climate models, if atall. One major obstacle here is that large portion of the GW spectrumhas to be parameterized itself in those models.
Recently, an asymptotic framework was introduced allowing forself-consistent description of the interactions between GW and iceclouds and analytical solutions were derived for the nucleated numberof ice crystals in a parcel model (Dolaptchiev et al., 2023).  Here,we evaluate the results from the asymptotic analysis in 3D idealizedexperiments with fully resolved GW, where the GW dynamics is forcingdouble-moment ice microphysics scheme. In addition, correspondingexperiments with parameterized GW dynamics are performed. In thosesimulations a next generation ray-tracing-based GW parameterization isused, which allows for an improved representation of the temporal andspatial GW variability. Within the present framework we develop andtest coupled GW-cirrus parameterizations for climate model.
References:
S. Dolaptchiev, P. Spichtinger, M. Baumgartner and U. Achatz, 2023,"Interactions between Gravity Waves and Cirrus Clouds: AsymptoticModeling of Wave-Induced Ice Nucleation", Journal of the AtmosphericSciences, https://doi.org/10.1175/JAS-D-22-0234.
A new, fast and unified subglacial hydrological model applied to Thwaites Glacier, Antarctica
Authors: Gregov Thomas , Kazmierczak Elise , Coulon Violaine , Pattyn Frank
Published: March 2024

Subglacial hydrology is a crucial element for understanding the dynamics of marine ice sheets. Indeed, the presence of subglacial water modulates the ice basal motion, resulting in a modified ice flow across the entire ice sheet. Nonetheless, the subglacial environment is difficult to reach, which makes it necessary to develop models. Many efforts have recently been made in the glaciological and hydrological communities to improve their accuracy and efficiency. Even so, the models currently being developed are typically fairly costly in terms of computing time. As a consequence, conducting numerical simulations over long time scales or running ensemble simulations remains particularly challenging.Here, we propose a simplified approach for coupling subglacial hydrology with the motion of ice. First, we introduce a computationally efficient subglacial hydrology model that is suited for hard and soft bed types as well as efficient and inefficient drainage systems. Then, we show some numerical results based on our implementation of this model within the Kori-ULB ice-sheet code. We first study the impact of subglacial hydrology in the idealized MISMIP configuration. Subsequently, we show results of simulations conducted over Thwaites Glacier which suggest that the coupling of subglacial hydrology with ice flow could significantly increase the contribution of marine ice sheets to future sea-level rise.
Polar Motion Prediction with Derivative Information
Authors: Ligas Marcin , Michalczak Maciej , Belda Santiago , Ferrandiz Jose M. , Modiri Sadegh
Published: March 2024

Our study introduces a hybrid model that combines least-squares (LS) extrapolation of a linear trend and periodic components with a vector autoregression applied to LS residuals in an attempt of enhancing polar motion (x, y) predictions through incorporating its rates (derivatives; x', y'). We used the historical daily sampled final IERS EOP 20 C04 time series available on https://www.iers.org as a reference for all computations. The prediction experiment covers 10 years, 01.03.2013 – 01.03.2023. Within this period, 1000 random samples with a length of one year were generated, with the starting modified Julian date (MJD) of each yearly sample randomized. Within each sample, a 30-day forecast was performed every 7 days, resulting in a total of 48 forecasts in each random trial. Polar motion rates were incorporated to the prediction procedure in various combinations, i.e., {x, x'}, {y, y'}, {x, y, x'}, {x, y, y'}, {x, y, x', y'} and the prediction results based on them were compared to the predictions obtained from the reference data combination {x, y}, which does not include derivative information. As a basic measure of prediction accuracy, we used the mean absolute prediction error (MAPE) as well as a number of measures indicating improvement through incorporating rates into the prediction procedure. The results indicate a noticeable gain in prediction accuracy with the use of derivatives, although not substantial, it is systematic. This improvement is particularly apparent for the first few days of the forecast, which might indicate its potential use in ultra-short-term prediction. This promising data combination (and prediction method) is worth further analysis and an attempt of adapting it for operational settings (real time forecast).