bluuebunny/crossref_metadata_2025 huggingface dataset:
Smoothed predicted distributions in digital soil mapping – a comprehensive comparative study to predict soil texture for irrigation
Authors: Nussbaum Madlene , Vogel Stefan , Oechslin Stefan , Tanner Simon , Burgos Stéphane
Published: February 2023

Spatial predictions for mapping soil properties are often prone to smoothing of distribution tails. As a result small values are overestimated and large values are underestimated. For many applications there might be not harm, but it is critical for map uses where soil property interpretation for small or large values have a substantial effect. For example, soil texture maps are relevant to implement irrigation strategies or to adjust irrigation soil moisture probes. Texture at the margin of the distributions have a much larger impact on probe adjustment than intermediate textures. To investigate the effect of different statistical approaches on smoothing of soil texture prediction we analyzed four Swiss data sets originating from different surveys with different strength of response-covariate relationships (weak: arable land north of Berne, n = 1650; weak to medium: arable land of Canton of Zurich, n = 3920; medium: strongly cultivated Gleysols and Histosol in Seeland/Grosses Moos, n = 2510; strong: cultivated Histosols in Rhine Valley, n = 2590). We evaluated behavior around lower and upper tails of predicted distributions for commonly used methods fitted to clay, silt and sand and to additive log-ratio transformed responses: random forest, gradient boosted trees, support vector machines, Cubist regression, k-nearest neighbor, robust external-drift kriging and group lasso. In addition, we applied approaches that are supposed to alleviate the problem of smoothed predicted distributions: 1) post-processing transformation to match original variance, 2) SMOTER algorithm for imbalanced regression, 3) constrained kriging, 4) random forest with resampling weights inverse to histogram, 5) univariate distributional random forest with a distribution loss criteria and a 6) multivariate response variant of distributional random forest. Validation was done by surveying a design-based dataset for Rhine Valley and Berne and by data-splitting otherwise. Besides computing validation statistics of mean model performance, we evaluated goodness-of-fit of univariate and multivariate distributions. Further, we judged the multivariate accuracy regarding HYPRES and USDA texture classes often used within irrigation applications. The comparative analysis of the used methods showed that no approach outperformed the others on all datasets regarding mean overall accuracy and at the same time satisfactory prediction of tails. Sometimes random forest with inverse histogram weights was resulting in slightly better predictions at the tails, but it was closely followed by an unaltered random forest. Hence, producing proper prediction along the full distribution of a response remains a challenge.
A Modeller’s Compass: How Modellers Navigate Dozens of Decisions
Authors: Remmers Janneke , ter Horst Rozemarijn , Teuling Ryan , Melsen Lieke
Published: February 2023

The usage of hydrological models is diverse and omnipresent. For practical purposes, these models are applied to, for example, flood forecasting, water allocation, and climate change impacts. Numerous methods exist to execute any modelling study. Choosing a method creates a narrative behind each model result. This implies that models are not neutral. So, how do modellers make these decisions? We conducted fourteen semi-structured interviews between September and December 2021 with nine modellers from six different water authorities and five modellers from four different consultancy companies in the Netherlands. The interviews were all recorded and transcribed. We executed an inductive content analysis on the transcriptions. We will discuss the motivation modellers have to make choices during the modelling process. With these insights, we aim to contribute to a discussion on how models, despite their unavoidable non-neutrality, can be robust and dependable to support decision making. Standardisation, e.g. automation, can be a way to achieve this. Understanding the social aspects behind the modelling process is necessary to move forward in modelling and modelling workflows, as well as being able to share and reflect on the model results including the narrative behind it.
The shadowlands of science communication in academia — definitions, problems, and possible solutions
Authors: Gani Shahzad , Arnal Louise , Beattie Lucy , Hillier John , Illingworth Sam , Lanza Tiziana , Mohadjer Solmaz , Pulkkinen Karoliina , Roop Heidi , Stewart Iain , Stiller-Reeve Mathew , von Elverfeldt Kirsten , Zihms Stephanie
Published: February 2023

Science communication is important for researchers, including those working in the geosciences. However, much of this work takes place in “shadowlands” that are neither fully seen nor understood. With the increasing expectation in academia that all researchers should participate in science communication, there is an urgent need to address some of the major issues that lurk in these “shadowlands”. Here the editorial team of Geoscience Communication seeks to shine a light on the “shadowlands” of geoscience communication and suggest some solutions and examples of effective practice. The issues broadly fall under three categories: 1) unclear or harmful objectives; 2) poor quality and lack of rigor; and 3) exploitation of science communicators working within academia. Ameliorating these will require: 1) clarity in objectives and audiences; 2) adequately training science communicators; and 3) giving science communication equivalent recognition to other professional activities.
Development of land use regression (LUR) models for criteria air pollutants in Delhi: Use of regulatory monitoring data
Authors: Upadhya Adithi , Kulkarni Padmavati , Kalshetty Mahesh , Srishti Srishti , Kushwaha Meenakshi , Agrawal Pratyush , Vakacherla Sreekanth
Published: February 2023

High-resolution spatial maps of air pollution can be useful for air quality management. In low- and middle-income countries, regulatory measurements of criteria pollutants are typically insufficient to generate spatial maps, due to the sparsely located monitoring stations. Alternatively, high-resolution spatial maps of air pollution can be achieved by dispersion (physics-based) and statistical regression (training-based) modelling. Resolutions of up to ~25 meters can be achieved by Land Use Regression (LUR) modelling based spatial predictions. In this study, we leveraged the high density of regulatory monitors located in New Delhi, India, and developed LUR models for all the major criteria pollutants (PM10, PM2.5, SO2, NO2, and Ozone). New Delhi is one of the most heavily polluted cities in the world. We used data from 40 continuous ambient air quality monitoring stations’ (CAAQMS) for the year 2019 to develop seasonal and annual LUR models, following the ESCAPE (European Study of Cohorts for Air Pollution Effects) stepwise supervised regression method. Model predictors included land use parameters, road lengths, rail track lengths, population, satellite pollution, and NDVI data, along with air pollution point source location data and reanalysis meteorology. The models were validated using leave one station out (LOSO) and 10-fold cross validations (CV). The model adjusted R2 values varied between 0.08 and 0.64. Particle pollutant models (PM2.5 and PM10) performed better than those of gaseous pollutants. Further, ozone models performed the least. Across seasons, summer models performed the best (least) for PM (gaseous pollutants). Models with adjusted R2 were used for spatial predictions at 50-m resolution for the Delhi National Capital Territory region. Spatio-seasonal characteristics of air pollution were studied using the generated high-resolution maps.
Intensification of terrace agriculture on the Northern Apennines during the Medieval Climate Anomaly
Authors: Brandolini Filippo , Kinnaird Tim C. , Srivastava Aayush , Turner Sam
Published: February 2023

Recent environmental studies and policies have recommended maintaining archaeological landscape features such as intercropping, agroforestry and cross-slope barriers (e.g. hedgerows, stone walls, earth banks) for their potential benefits to ecosystems. This study focuses on a portion of the Tuscan-Emilian Apennines coinciding with the municipality of Vetto d'Enza (commonly referred as Vetto), located on the right bank of the Enza River in the Man and the Biosphere UNESCO reserve (Emilia-Romagna region, Northern Italy). The main characteristics of this historic rural landscape trace their origin back to the Middle Ages at the period of the Great Countess Matilda of Canossa (10-11th century CE) and the area’s land management system appears to have remained largely unaltered until the end of the 19th-century CE. Among the most distinctive characteristics of this historic landscape are relicts of agroforestry practices (known as ‘alberata emiliana’) and well-preserved stone walls and earth banks that have been used extensively between steeply-sloping fields to delimit tenurial boundaries and to face agricultural terraces. Optically stimulated luminescence profiling and dating (OSL-PD) has been applied to date the sediments associated with earth banks, stone walls and agricultural terraces. The results provide secure construction dates during the Medieval Climate Anomaly - (MCA). This period (ca. 900–1350 CE) is arguably one of the most crucial moments of recent climate change that impacted societies, particularly in Europe. Above average temperatures allowed high-elevation settlements to persist throughout the MCA, though social trends played a large role in the conversion of uplands into an agro-pastoral landscape. These processes are particularly evident on the Apennine mountains, where mediaeval deforestation coincided with intensification of agriculture associated with development of monastic estates that exploited increasingly larger land holdings as well as new settlement patterns in higher-elevation defensible locations.
Biogeosciences and terroir analysis
Authors: Bonfante Antonello
Published: February 2023

Terroir is a complex concept aiming to express "collective knowledge of the interactions" between the environment and the vines mediated through human action and "providing distinctive characteristics" to the final product (OIV 2010).The popular press often treats and communicates it without a proper understanding of the mechanistic relationships between the wine characteristics and the site. These relationships are primarily rooted in the physical environment, particularly in the interactions between the soil-plant and atmosphere system, affecting grapevine physiology, grape composition, and wine (the terroir expression).Terroir studying and mapping are based on viticultural zoning procedures, realized with different levels of know-how at different spatial and temporal scales, empiricism, and complexity in the description of involved bio-physical processes, integrating or not the multidisciplinary nature of the terroir. The scientific understanding of the mechanisms ruling vineyard variability and the quality of grapes is one of the most important scientific focuses of terroir research. This knowledge can support the analysis of climate change impacts on terroir resilience, the identification of new promise land for viticulture, and drive vineyard management toward a target oenological goal.In this context, the contribution of biogeosciences is fundamental to producing more accurate and reliable approaches to studying and analysing terroir.This contribution will show an overview of the current approaches and applied technologies in terroir studies, with special attention to the identification of terroir zones.
Measured temporal variations of CO2 concentration and atmospheric emissions in a hydropeaking-impacted river
Authors: Dolcetti Giulio , Piccolroaz Sebastiano , Bruno Maria Cristina , Calamita Elisa , Larsen Stefano , Zolezzi Guido , Siviglia Annunziato
Published: February 2023

Rivers are increasingly recognised as active players in the global carbon cycle. They are able to transport, transform, and exchange organic matter, and can emit considerable fluxes of greenhouse gases (e.g., CO2) into the atmosphere, with a magnitude comparable to the global carbon input to the oceans. However, the quantification of these processes is still affected by considerable uncertainties, driven by an incomplete understanding of the interplay between physical, geochemical, and biological parameters, and by a lack of spatially and temporally resolved high-quality data. For instance, and despite a potentially strong impact on kilometres of rivers worldwide, the effects of hydropeaking on riverine CO2 emissions have been almost completely neglected until recently (Calamita et al., Unaccounted CO2 leaks downstream of a large tropical hydroelectric reservoir, PNAS 2020). As a contribution to filling this knowledge gap, we present the results of a field-measurement campaign performed in a single-thread Alpine river (River Noce, Italy) during multiple hydropeaking events. Data of water-dissolved CO2, water temperature, and flow discharge, were collected sub-hourly both downstream and upstream of the outlets of a hydropower plant, revealing a complex pattern of variation in time at both locations. Water released from the hydropower plant during hydropeaking had oversaturated CO2 concentrations relative to the atmosphere, in close agreement with water samples collected in the hypolimnion of the upstream reservoir. Higher flow rates during hydropeaking events were associated with higher rates of gas exchange through the water-air interface. Higher exchange rates and higher CO2 concentrations in water during hydropeaking events enhanced CO2 fluxes, as confirmed by measurements with a floating CO2 flux chamber. Meanwhile, the CO2 concentration upstream of the outlets displayed strong diel fluctuations around the atmospheric equilibrium concentration, which were likely driven by primary production within the residual flow during the day. It is shown that the residual flow can have a previously unacknowledged added value as a CO2 sink during the day, fueled by its biological activity. Hydropower releases bypassed the residual flow and discharged hypolimnetic water oversaturated with CO2 at high flow rates during hydropeaking, offsetting CO2 concentration and fluxes downstream of the outlets and increasing emissions on average. These results highlight the ubiquity of hydropeaking impacts also with respect to greenhouse gas emissions. They illustrate the complexity of the riverine carbon cycle and demonstrate the importance of temporally and spatially-resolved data for the accurate assessment of the riverine carbon balance.
CMIP6/OMIP simulations of the Arctic Ocean and the impact of resolutions
Authors: Guo Chuncheng , Shu Qi , Wang Qiang , Nummelin Aleksi , Bentsen Mats , Gupta Alok , Gao Yang , Zhang Shaoqing
Published: February 2023

Underlying the polar climate system are a number of closely coupled processes that are interconnected through complex feedbacks on a range of temporal and spatial scales. Observations are limited in these inaccessible and remote areas, and understanding of these processes often relies on regional and global climate modelling. However, large uncertainties remain due to unresolved key processes in both the regional and global contexts.In this presentation, we first show that large model spread and biases exist in simulating the Arctic Ocean hydrography from the latest CMIP6/OMIP experiments. Our results indicate that there are almost no improvements compared with the previous CORE-II experiments (with similar OMIP-like protocol) which were thoroughly assessed by the ocean modelling community. The model spread and biases are especially conspicuous in the simulation of subsurface halocline and Atlantic Water, the latter often being too warm, too thick, and too deep for many models. The models largely agree on the interannual/decadal variabilities of key metrics, such as volume/heat/salt transport across main Arctic gateways, as dictated by the common atmospheric forcing reanalysis.We then examine a hierarchy of global models with horizontal resolutions of the ocean on the order of 1-deg, 0.25-deg, and 0.1-deg. For the 0.1-deg resolution, we take advantage of a recent unprecedented ensemble of high-resolution CESM simulations, as well as NorESM simulations of similar ocean resolution but of shorter integration. High(er) resolutions show signs of improvements and advantages in simulating the Arctic Ocean, but certain biases remain, which will be discussed together with the challenges of high-resolution simulations in the region.
Evidence of sub-surface water flow dynamics within a karst conduit from ambient noise monitoring
Authors: Pantiga Axelle , Allègre Vincent , Lastennet Roland , Houillon Nicolas , Mateo Sylvain , Naessens Fabien , Denis Alain
Published: February 2023

Karst aquifers are characterized by their heterogeneity and complex underground geometry. A great part of the world relies on karst resources for drinkable water and understanding the functioning of karst systems is essential to assess their vulnerability and response to rainfall. Relevant continuous parameters to quantify the underground flow dynamics are still required for these studies as direct underground measurements are not possible. We used surface ambient noise measurements to estimate the seismic signature and amplitude associated with the water flow within an underground karst conduit. We combined geophysical measurements with hydro-chemical and hydrogeological data to build a multidisciplinary approach. The experimental site is the Glane spring, in Dordogne (France). The hydrogeological catchment of this Vauclusian-type spring is 75 km² and consists of upper Jurassic carbonate rocks. The Glane spring shows rapid and intense variations of discharge following rainfall events, ranging from 0.1 to 4 m3/s in 2021. Ambient noise has been continuously recorded since December 2021 using four seismic stations deployed upstream of the source and above the well-known karst terminal conduit. Hydro-chemical parameters and water level have been continuously monitored during a full hydrological cycle and a rain gauge was installed on site to monitor rainfall. During the first year of monitoring, we identified six flooding events. Each event was characterized by an increase in water flow associated with an increase in the seismic signal amplitude. We observed that the seismic amplitude standard level is higher during the high-water period than during the low water period suggesting a larger base water flow. We also observed hysteresis between the seismic power and hydro-chemical parameters. Correlations between the seismic recordings and hydrochemistry might suggest a change in water flow regime within the conduit prior to the flood. Seismic power variations associated with discharge variations are similar to what was already observed for sub-glacial melting flow. Other springs and swallow holes are currently instrumented to validate the approach in the field.
Forecasting ICME induced Satellite Orbit Decays
Authors: Drescher Lukas , Kroisz Sofia , Krauss Sandro , Temmer Manuela , Suesser-Rechberger Barbara , Strasser Andreas
Published: February 2023

Geomagnetic storms are capable of triggering thermospheric density variations which in turn have an influence on the trajectory of low Earth orbiting satellites (LEO). The strongest of these disturbances of the thermosphere are caused by interplanetary coronal mass ejections (ICMEs). Due to increases in the neutral mass density during such ICME induced geomagnetic storms the altitude of satellites will decrease. Therefore, ICME induced orbit decays are important for long-term orbit prediction as well as short-term as the prominent example of the so called ‘Starlink’ event of February 2022 showed where 40 satellites reentered the atmosphere.
In order to calculate the ICME induced orbit decay we calculated the thermospheric neutral mass density through the deceleration due to drag. This is done either with an observation approach using the high orbiting global navigation satellite system (GNSS) or calibrated data from onboard accelerometers. We then relate the solar wind plasma and magnetic field measurements taken at L1 from the ACE (Advanced Composition Explorer) and the DSCOVR (Deep Space Climate Observatory) satellites to the calculated ICME induced orbit decays. 299 ICMEs occurred during the operation of the GRACE (Gravity Recovery And Climate Experiment) satellite which orbits at an altitude of around 490 km. Analysis of the ICME induced orbit decays and the interplanetary magnetic field at L1 show a strong correlation as well as a time delay between the ICME and the associated thermospheric response of around 15 hours on average. This correlation is implemented in the real time forecasting tool SODA (Satellite Orbit DecAy). Because the ICME induced orbit decay strongly depends on the altitude we additionally processed data from the CHAMP (CHAllenging Minisatellite Payload) satellite mission to cover the range of 400 km altitude. The GRACE focused forecast algorithm SODA is part of the project SWEETS and ESPRIT, which will be implemented in the ESA Space Safety Program (Ionospheric Weather Expert Service Center) in 2023.
Carbon and nitrogen services from cover crops are optimized by including legumes in mixtures
Authors: De Notaris Chiara , Mortensen Esben , Liang Zhi , Chiriacò Maria Vincenza , Rasmussen Jim
Published: February 2023

Cover crops are cultivated during unproductive periods to provide ecosystem services, such as preventing nitrogen (N) leaching, and have the potential to increase soil organic carbon (C), thus contributing to climate change mitigation. Their effect on soil C storage depends on C input, which is challenging to quantify due to belowground sampling (roots and C deposited in the soil). Leguminous cover crops (in pure stands or in mixtures) increase the productivity of following main crops due to high N input, but also the risk of N losses, compromising the mitigation effect. As C and N services vary with cover crop type, tradeoffs could be minimized by species selection. The aim of this study was to assess C input from different cover crop species and mixtures, as well as N uptake in their biomass, and their effect on soil mineral N (SMN) and yield of the following crop.We conducted a field experiment in 2020-2021 at Foulum, Denmark (temperate oceanic climate, sandy loam soil), with seven treatments (five cover crops, control with volunteers, and bare soil) replicated four times. Cover crops undersown in spring barley (Hordeum vulgare L.) in May 2020 were: Lolium perenne L. (ryegrass, RG), Trifolium pratense L. (red clover, RC), Plantago lanceolata L. (plantain, PL) and the mixtures RG-PL and RG-PL-RC. On August 24, 2020, after barley harvest, PVC cylinders (diameter: 29.5 cm, height: 30 cm) were inserted in each plot (25 cm depth) and used for 13C-CO2 multiple-pulse isotopic labeling. Two sessions per week were conducted until cover crop sampling in November 2020, when C and N in above- and belowground biomass, as well C deposited in the soil were determined. Monthly soil sampling (20 cm depth) was performed from August 2020 until April 2021 to assess SMN. Then barley was sown to evaluate cover crops residual effect.Aboveground biomass was lowest in RG (1.5 Mg ha-1), and highest in RG-PL-RC (5.4 Mg ha-1). Total C input (above- and belowground) ranged from 1.6 to 4.3 Mg ha-1, with RG-PL-RC (highest) being significantly higher than RG-PL and RG (lowest). The same pattern applied to total N input, ranging from 74 to 202 kg ha-1. All cover crop treatments had lower SMN than bare soil and volunteers in August 2020. SMN increased from August until April 2021 with all cover crops except RG, and decreased with bare soil and volunteers. SMN in April was 15 kg ha-1 higher with RC and RG-PL-RC than RG. Barley yield following leguminous cover crops was comparable to plots fertilized with 100 kg ha-1 of mineral N, while non-legumes to 40 kg ha-1. Overall, the mixture with RC provided the greatest C input and positive residual effect. The small change in SMN in April indicate that biomass N was converted into mineral N and taken up by barley during the growing season, thus not increasing the risk of N losses.
Representing the effect of (de)compaction on soil hydraulic properties using segmental constitutive laws
Authors: Kiałka Filip , Flores Omar , Naudts Kim , Luyssaert Sebastiaan , Guenet Bertrand
Published: February 2023

Soil (de)compaction is widespread and has a large impact on soil constitutive relationships including hydraulic and gas-exchange properties. Surveys estimate that about a third of EU soils are severely degraded by compaction, and lab experiments show that the effect of compaction on soil hydraulic conductivity can be as large as the differences between textural classes. Nevertheless, the effect of (de)compaction on soil properties remains absent or only provisionally represented in present-day soil-crop, ecosystem, and land-surface models. That is despite the formulation of soil structure evolution models for key land management practices, biotic factors, and wet-dry or freeze-thaw cycles. The slow maturing and uptake of these models results from observational limitations and from difficulties with upscaling and with relating their outputs to soil properties of interest. Here we address the latter by extending established models of soil hydraulic properties to represent a dynamically evolving soil structure parametrized by a discrete pore-size distribution. The extension decomposes a given water retention curve into smooth algebraic segments corresponding to predefined pore size classes. The segments are then individually scaled to represent the changing pore volumes and summed to obtain the new retention and conductivity functions. We validate this approach using lab-based compaction experiments and demonstrate its use at site scale by leveraging the soil hydrology scheme of the ORCHIDEE land surface model. Finally, we discuss new applications that our approach enables, with a focus on representing the interaction between ecosystem engineers, soil structure, and soil water.
Imaging the Magmatic Plumbing System beneath Askja Caldera, Iceland with Seismic Tomography
Authors: Han Jifei , Rawlinson Nicholas , Winder Tom , Greenfield Tim , White Robert , Brandsdóttir Bryndís
Published: February 2023

Askja caldera is a large central volcano located in the Northern Volcanic Zone in Iceland. It has experienced a number of eruptions in modern history with one of the largest taking place in 1875, from which tephra managed to travel as far as Germany. After its most recent erup- tion in 1961, GPS measurements have shown that deflation has continued since the 1970s, which may primarily be caused by the cooling of a magma body at a depth of around 2 km below sea level, as suggested by geodetic modelling. In ~September 2021, the Askja caldera switched from deflation to inflation. This has caused a lot of excitement in the seismology and volcano communities, with increased monitoring and data collection beginning in earnest in an attempt to better evaluate the progress and potential outcomes of this interesting phenomenon.
My study aims to image the magmatic plumbing system beneath the top ~10 km of the Askja caldera and the surrounding region using seismic tomography. The dataset consists of the first arrival picks of P- and S-waves from local earthquakes. The initial dataset is sourced from Greenfield et al. (2016), but additional picks from more recently collected data are also incorporated to enhance ray coverage. These arrival times are inverted using the FMTOMO package, which jointly constrains hypocenter location and 3-D Vp, Vs and Vp/Vs structure using an iterative non-linear approach, in which the forward problem of traveltime prediction is solved using the Fast Marching Method (Rawlinson et al., 2005).
The final tomographic results yield a variety of wavespeed anomalies that can be associated with the volcanic plumbing system. Of particular note is a low Vp, low Vs and high Vp/Vs anomaly at around 2 km depth below the caldera, a feature that has previously not been observed in seismic imaging results. A low wavespeed anomaly also connects the mid-crust with the surface below the edifice, which is consistent with the flux of melt through the crust. Synthetic checkerboard and spike tests indicate that these features are constrained by the data.

References
Rawlinson, N. and Sambridge, M. (2005). The fast marching method: an effective tool for tomographic imaging and tracking multiple phases in complex layered media. Exploration Geophysics, 36(4):341.
Greenfield, T., White, R. S., and Roecker, S. (2016). The magmatic plumbing system of the Askja central vol- cano, Iceland, as imaged by seismic tomography. Journal of Geophysical Research: Solid Earth, 121(10):7211– 7229.
Quantifying the added value of underway pCO₂ data from sailboats
Authors: Behncke Jacqueline , Landschützer Peter
Published: February 2023

The ocean regulates the climate by annually absorbing roughly 25 % of anthropogenic CO2 emissions from the atmosphere. In order to quantify the capacity of the ocean carbon sink from observations, measurements of the sea surface partial pressure of CO2 (pCO2) are essential. Building on the existing observational networks, we can utilize neural networks and other statistical methods, to interpolate data gaps in time and space creating homogeneous pCO2 maps to estimate the exchange of CO2 through the air-sea interface. However, uncertainties in these neural network interpolations are still substantial, particularly in less frequently monitored ocean regions such as the Southern Ocean. Trying to close existing data gaps, MPI is working with a novel, cost efficient and environmentally friendly fleet: sailboats. Sailboat pCO2 has been regularly collected since 2018, however, their added value has not yet been quantified.Here, we quantify the added value and rate of improvement of underway pCO2 data from such racing events by creating a twin of all available SOCAT observations, excluding data from sailboat races. We apply the SOM-FFN technique on all pCO2 observations in SOCAT as well as the twin dataset and calculated the sea surface pCO2 and subsequently the air-sea CO2 exchange. By comparing the reconstructive air-sea CO2 fluxes, we were able to quantify the difference, representing the added value of sailboat racing events.Our results show that the reconstructions on SOCAT and the twin dataset significantly differ in the air-sea CO2 flux density on regional scales by up to 1.26 mol m-2 yr-1. 99 % of the significant differences fall below 0.40 mol m⁻² yr⁻¹. While differences are within the noise in many regions, significant differences can be detected in the less frequently monitored Southern Ocean, where pCO2 data from single events, such as the Vendée Globe are added, as well as in the North Atlantic, where the majority of racing events took place. While the results after 5 years of data collection do not show a significant effect when globally integrating the air-sea CO2 exchange, our results highlight the potential of sailing yachts as an observational platform, particularly in less frequently navigated ocean regions. We conclude that sailboat races provide a complementary observing platform to research vessels and robotic floats. Considering the recurrence of sailboat races, they have the potential to improve reconstructive air-sea CO2 flux estimates on a larger scale in the future.
Additions of ochre to soil increase the retention of organic carbon
Authors: Hodson Mark E , Islam Mahmuda , Metcalf Matty , Wright Amy
Published: February 2023

Fe oxyhydroxides are known to adsorb organic carbon in soil, protecting it from degradation. In this presentation we will report the results of experiments in which we added waste ochre (Fe oxy-hydroxide) precipitated by waters draining former UK coal mines to soils and observed decreases in carbon lability and thus increased carbon storage. In batch experiments in which ochre was added to soil at rates of 5 wt % and 10 wt % by mass and shaken in 20 mL 0.01 M CaCl2, organic carbon release into solution was significantly reduced suggesting that the ochre had adsorbed organic carbon. In an initial set of plant growth experiments soil was amended with 5 wt% ochre and wheat plants grown for 6 weeks. The concentration of organic carbon leached from the soil over the course of the experiment and the hot water extractable organic carbon at the end of the experiment were significantly reduced by c. 43 % and 16 % respectively indicating a reduction in carbon lability. However, plant growth was reduced by c. 50 % by the ochre amendments. As Olsen P was reduced by the ochre amendments we ascribe this growth reduction to reduced P availability due to adsorption of P to the ochres. In a follow up set of experiments we added both ochre and KH2PO4 to soils. The KH2PO4 was added at a rate equivalent to levels of recommended P fertiliser application in the UK. In this second plant experiment, there was no difference in plant biomass between the study control and the ochre-treated soils and carbon lability was still significantly reduced by the ochre treatments. In addition to this the ochre amended soils leached less phosphate over the course of the experiment. These results suggest that Fe oxide amendments to soil may be a practical way of changing soil chemistry in order to increase the amount of carbon retained in soils but that care must be taken to ensure that phosphorus availability is not negatively affected. However, rough calculations indicate that the global supply of Fe-rich waste may be insufficient for Fe-oxide waste amendments to generate significant increases in soil carbon at a global scale. So addition of Fe-oxide wastes may represent a local means of waste-generating industries to offset their carbon footprint.
Planktonic Foraminiferal δ13Corg as a novel proxy for Carbon Cycling
Authors: Paoloni Tommaso , Hoogakker Babette , Grant Helen , Keenan Patrick , Hamilton Helliot
Published: February 2023

It has been hypothesized that lower atmospheric CO2 concentrations and lower temperatures during glacial times caused the enrichment of carbon isotopes of particulate organic material (δ13Corg-POM) produced in the surface ocean. Some downcore measurements of organic carbon isotopes of bulk sediments show such a trend, however, others do not. The lack of a coherent picture could be due to issues relating to the bulk sediments, including diagenetic alteration, the nature of the organic material, input of allochthonous material, and sediment redistribution.Recent work by Hoogakker et al. (2022) shows that planktonic foraminifera-bound organic carbon δ13C values (δ13CFBOM) are remarkably similar to those of δ13Corg-POM. Here we present the first down-core organic carbon isotope record of planktonic foraminifera-bound organic carbon (δ13CFBOM) from the Southern Ocean (ODP Site 1088), to test for a glacial enrichment in δ13Corg-POM. The samples (Globigerina bulloides, Globorotalia truncatulinoides, and G. inflata) cover the last 20,000 years.Our δ13CFBOM results show a slight positive trend toward the Last Glacial Maximum (LGM), in accordance with the hypothesized δ13Corg-POM trend, but not to the extent as shown in some bulk sediments from more tropical latitudes. We discuss our results in the context of predicted past δ13Corg-POM using ice core atmospheric pCO2 concentrations, G. bulloides calcification DIC (from inorganic carbon isotopes), and temperature (using Mg/Ca). 
Impacts of technically modified plant pits on water balance dynamics and tree vitality in urban environments
Authors: Nofz Ines A. , Becker Joscha N. , Eschenbach Annette
Published: February 2023

Trees as essential components of green urban structures are of crucial importance for the regulation of the urban climate and human wellbeing. Despite this, the currently rising demand for living space and infrastructure causes an increase in the share of sealed and compacted soils. These trends directly affect soil-plant interactions in urban environments. The synergy of the increasing land use pressure and changing climatic conditions worsen the site and growth conditions and thus the vitality for young and mature trees. A possible adaptation strategy is the transformation of plant pits into water reservoirs combining the discharge of excess water with impermeable sole materials and substrates that optimise the water conductivity and storage capacity. The corresponding aim of this study is the quantification of the effects of the water balance dynamic in the rooting zone on the vitality of young trees at highly sealed sites in the city of Hamburg. The two main questions are 1) Do technically modified plant pits reduce summerly drought stress inside the rooting zone and thus improve the root water uptake and tree vitality?, and 2) Does excess water after high rainfall limit the gas exchange and thus the root growth? To answer these questions, we selected two different sites, one residential area and one pedestrian zone. A total of 13 tree planting pits, including 5 technically modified and 8 generally constructed ones, with two types of substrates and water discharge, are equipped with TDR- and water tension sensors for a continuous monitoring of the soil water balance and O2 and CO2 sensors and tubes for monitoring the gas household. Stomatal resistance, chlorophyll content and fluorescence as well as Δ13C isotope measurements are combined with branch and trunk growth measurements and a tree appraisal to investigate the tree vitality. The comparative data analysis will be used for evaluating the different planting pit variants to give development as well as dimensioning recommendations for prospective planting pit constructions, improving the soil-plant interaction.
Influence of the extraordinary Filomena snowstorm on the surface energy balance and its relationship with the subsequent very-low surface temperatures
Authors: Fernández-Castillo Pablo , Román-Cascón Carlos , Yagüe Carlos
Published: February 2023

Filomena snowstorm impacted a large part of the Iberian Peninsula during January 2021, especially affecting the central part of Spain, and covering the Madrid region with up to 50 cm of snow.In this work, we analyse data from a micrometeorological station (GuMNet-Herrería) placed in a rural environment in the northwest of the Community of Madrid. The objective is to determine the influence of the microscale on the extremely low temperatures reached after Filomena's passage, as well as to better understand the physical processes associated with these extreme conditions.Although the snowfall lasted only for 2 days, the snow was present on the surface for more than 10 days, already with stable synoptic conditions, accompanied by a weak turbulent transfer between the surface and the lower part of the atmospheric boundary layer. These days after, extremely low temperatures were recorded, reaching minima of up to -26.5 ºC in the central part of the Iberian Peninsula. The presence of snow on the surface modified significantly the components of the surface energy balance (SEB). This included a reduction in the available net radiation at the surface as result of increased albedo and emissivity of the surface, compared to standard conditions (previous period to Filomena), as well as in the turbulent fluxes, contributing to some records of minimum temperatures. The persistence of the snow cover also affected the soil temperatures, keeping the ground heat flux practically constant.
Cation exchange reversibility of potassium-ammonium binary solution: effect of organic matter
Authors: Nguyen Bich-Thao , Arye Gilboa
Published: February 2023

Soil fertility refers to the capacity of soil to support plant growth and development. Cation exchange capacity (CEC) is a fundamental measure of soil fertility quantifying soil's ability to retain essential cation nutrients such as potassium, ammonium, calcium, and magnesium, serving as a reservoir for soil native cations and artificially applied ones. However, soils are a finite resource and therefore subjected to unprecedented pressure due to rapid human population growth, agricultural activity, and food consumption, resulting in unsustainable soil degradation. For this reason, the application of exogenous organic matters (EOMs) such as biosolid, compost, manure, and biochar, is regarded as one of the most sustainable approaches for enhancing soil fertility, plant growth, and yield, soil carbon content, microbial biomass, and activity as well as preventing desertification by improving soil structure stability. Given the diverse origins of organic amendments from agriculture, forestry, industry, or wastewater-derived biosolids, their physical and chemical properties are different and may differently affect the adsorption and affinity of nutrient cations such as NH4+ and K+. Understanding the intrinsic properties of these EOMs in conjunction with the K-NH4 cation exchange behavior would improve our understanding of K-NH4 fertility management in organic matter-amended soil. The motivation for this study is the recognized knowledge gaps regarding cations exchange in organic materials, in particular, exchange reversibility. The main objective of this study is to quantify the cation exchange reversibility of K-NH4 in EOMs and to assess the hysteretic desorption behavior. Binary exchange experiments were conducted in which soils or organic materials were pre-saturated with NH4+. The results were analyzed based on the Gapon equation and the Freundlich model. The results demonstrated significant differences between soil and organic materials in adsorption capacity and selectivity of K+ and NH4+. In the desorption phase, the hysteretic desorption of K+ and NH4+ was observed and found to be concentration dependent. In our presentation, the results of exchange isotherm and adsorption-desorption will be presented and discussed.    Keywords: soil organic matter, cation exchange, selectivity coefficient, adsorption, desorption, potassium, ammonium.
Digital Twinning of Geophysical Extreme Phenomena (DT-GEO)
Authors: Carbonell Ramon , Folch Arnau , Costa Antonio , Orlecka-Sikora Beata , Lanucara Piero , Løvholt Finn , Macias Jorge , Brune Sascha , Gabriel Alice-Agnes , Barsotti Sara , Behrens Joern , Gomes Jorge , Schmittbuhl Jean , Freda Carmela , Kocot Joanna , Giardini Domenico , Afanasiev Michael , Galves Helen , Badia Rosa
Published: February 2023

Destination Earth initiative pursues the implementation of a digital model of the Earth. With the aim to help understand and simulate the evolution and behavior of the Earth system components, to aid in better forecasting the impacts on human system processes, ecosystem processes and their interaction. The current state of the art technologies in numerical computations (HPC), data infrastructures (involving data storage, data access, data analysis), enable the possibility of developing numerical clones mimicking Earth’s geophysical extreme phenomena.A Digital Twin for GEOphysical extremes (DT-GEO),is a new EU project funded under the Horizon Europe programme (2022-2025), with the objective of developing a prototype for a digital twin on geophysical extremes including earthquakes, volcanoes, tsunamis, and anthropogenic-induced extreme events. It will enable analyses, forecasts, and responses to “what if” scenarios for natural hazards from their genesis phases and across their temporal and spatial scales. The project consortium brings together world-class computational and data Research Infrastructures (RIs), operational monitoring networks, and leading-edge research and academia partnerships in various fields of geophysics. It mergesthe latest outcomes from other European projects and, Centers of Excellence. DT-GEO will deploy and test 12 Digital Twin Components (DTCs). These will be self-contained entities embedding flagship simulation codes, Artificial Intelligence layers, large volumes of (real-time) data streams from and into data-lakes, data assimilation methodologies, and overarching workflows for deployment and execution of single or coupled DTCs in centralized HPC and virtual cloud computing Ris. (DT-GEO: A Digital Twin for GEOphysical extremes, project ID 101058129)
Microplastic distribution characteristics and storage in a multi-species saltmarsh
Authors: Zhang Yan , Wang Yanting , Chen Xiaogang , Zhu Peiyuan , Jing Siyuan , Li Ling
Published: February 2023

Plastic has greatly changed modern society, and it has become an indispensable material in our daily lives. Microplastics are now regarded as the serious environmental threats due to the management limitations. Saltmarshes are one of the most productive ecosystems on earth and a high-efficiency blue carbon sink. As an emerging contaminant, the load, transport and fate of microplastics are largely neglected in saltmarshes. Here, we firstly measured the mass concentration of microplastics in the sediment cores of a multi-species saltmarsh by pressurized liquid extraction and modified double-shot pyrolysis gas chromatography-mass spectrometry. The major microplastics in saltmarsh sediments were polyethylene (PE), polyvinyl chloride (PVC), and polypropylene (PP). The microplastic mass concentration in the sediment of Scirpus mariqueter was greater than Phragmites australis and mudflat. As artificial carbon, carbon content of microplastics accounts for 1.15% of total organic carbon. Overall, the results suggest that saltmarsh vegetation can efficiently drive the microplastic settling and retention. Therefore, the microplastic distribution characteristics in saltmarsh can be effected by the vegetation types and their distribution pattern.
Understanding the Stratospheric Response to Arctic Amplification
Authors: Mudhar Regan , Geen Ruth , Lewis Neil , Screen James , Seviour William , Thomson Stephen
Published: February 2023

Recent studies propose that Arctic sea ice loss and associated warming influence wave propagation into the stratosphere, affecting the winter polar vortex. Through stratosphere-troposphere coupling, this may perturb the winter jet stream and affect surface weather. But the “stratospheric pathway” linking Arctic variability to midlatitude weather extremes is not well understood. For example, studies such as the Polar Amplification Model Intercomparison Project (PAMIP) have not found a robust stratospheric response to Arctic sea ice loss, in strength nor sign.Here, we use an idealised atmospheric modelling framework (Isca) to better understand mechanisms and uncertainties in the stratospheric polar vortex response to Arctic amplification. We use Newtonian relaxation of temperature to a specified equilibrium temperature to simulate northern hemisphere winter, and force the model with an adjustable polar heating. Consistent with previous work, the vortex weakens in response to the imposed heating. Notably, we find a dependency on heating depth; vortex variability and sudden warming frequency reduces with increasing depth. This is relevant to PAMIP given previous work suggesting that atmosphere-only GCMs likely underestimate the depth of sea ice loss-induced atmospheric warming compared to fully coupled ones, and that the Arctic amplification link to midlatitude weather is sensitive to the vertical extent of polar warming. As such, our results should help to improve understanding and reduce biases in such comprehensive models.