bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes in cloud activity of ship exhaust particles: Potential effects on Arctic mixed-phase clouds
Authors: Santos Luis , Salo Kent , Frostenberg Hannah , Kong Xiangrui , Noda Jun , Kristensen Thomas , Ohigashi Takuji , Ekman Annica , Ickes Luisa , Thomson Erik
Published: February 2023

Maritime shipping remains a large source of anthropogenic airborne pollutants, including exhaust particles that can act as cloud condensation nuclei (CCN). The International Maritime Organization (IMO) imposed global fuel sulfur content (FSC) limits on marine fuels in order to target ship exhaust sulfur oxides and particulate matter emissions, but has allowed competing pathways to regulatory compliance; i.e., low FSC fuels versus exhaust after-treatment. Laboratory experiments revealed that these compliance measures have secondary effects on physicochemical properties of exhaust particles, affecting their CCN activity (Santos et al., 2022a; 2022b). We observe that combustion of low FSC fuels results in emissions of highly hydrophobic particles, causing significant reductions in CCN emissions, whereas wet scrubbing leads to an increase in CCN activity.
One area of focus is the Arctic region, which has been shown to be particularly susceptible to the effects of climate warming. A steady decrease in observed sea ice cover amplifies the regional warming (Screen and Simmonds, 2010), but also opens the region to increased ship traffic which may result in further climate feedbacks (Stephenson et al., 2018). It is of particular interest to identify how increased ship exhaust particle emissions may affect cloud processes; for example, by facilitating liquid droplet formation and thus, potentially changing the radiative properties of the aerosol and clouds.
Here, we investigate how increased shipping activity potentially influences the properties of Arctic mixed-phase clouds. In our study the experimentally observed characteristics of marine particle emissions and their liquid droplet forming potential have been implemented in large eddy simulations. We use the MIMICA model (MISU/MIT Cloud-Aerosol model) (Savre et al., 2014) to simulate a stable stratiform mixed-phase cloud based on the Arctic Summer Cloud Ocean Study (ASCOS) (Tjernström et al., 2014). A range of input parameters for ship aerosol, including size distributions, number concentrations, vertical distributions and hygroscopicities, has been studied to assess the potential impact on cloud properties and regional climate.
Santos et al. (2022a). Environ. Sci.: Processes Impacts, 24:1769-1781
Santos et al. (2022b). Environ. Sci.: Atmos., Advance Article
Savre et al. (2014). J. Adv. Model. Earth Syst., 6:630-649
Screen and Simmonds (2010). Nature, 464(7293):1334–1337
Stephenson et al. (2018). Geophys. Res. Lett., 45:9898–9908
Tjernström et al. (2014). Atmos. Chem. Phys., 14:2823-2869
New method for retrieval surface UV albedo from Lidar Surface Returns (LSR) of Aeolus
Authors: Labzovskii Lev , van Zadelhoff Gerd-Jan , Tilstra Gijsbert , De Kloe Jos , Donovan David
Published: February 2023

Here, we report results paving the way toward a new method for retrieving surface albedo at 355 nm from lidar surface returns (LSR) of Aeolus. We found that averaged monthly LSR estimates at 2.5 x 2.5 grid clearly varied depending on the land type with the signal strength descending as follows: snow, arid areas, vegetation, water surfaces. Most importantly, given the difference in the instrumental setup, Aeolus LSR exhibited unexpectedly high agreement with Lambertian Equivalent Reflectance from TROPOMI and GOME-2 with correlation coefficients (r) of ~0.87 at global scales for median estimates at the study period (r = 0.91 for TROPOMI-GOME-2) and regional estimates for 37 selected areas (r > 0.90) where the agreement is driven by land surfaces with lower agreement over water due to inherently different physics of Aeolus LSR. Aeolus LSR showed superior sensitivity to the change of land type from vegetation to arid, compared to GOME-2 or TROPOMI as indicated by the highest negative agreement between Aeolus LSR, compared to GOME-2 or TROPOMI. We anticipate that our results will lay the foundation for the multiyear surface UV albedo climatology during the entire Aeolus lifetime. 
Redox capacities of different types of clay minerals and their potential to immobilize redox-active radionuclides
Authors: Hoving Alwina , Griffioen Jasper
Published: February 2023

Clay minerals play an important role as barrier in radioactive waste storage. In addition to their function as hydraulic barrier, clay minerals can also immobilize radionuclides by adsorption and redox reactions with radionuclides. Reduction of redox-active radionuclides such as  technetium and selenium by smectites has already been shown. Many clay minerals contain iron (Fe) in their structure, however, not all of this structural Fe is accessible for redox reactions. This can depend on multiple factors such as the quantity and coordination of Fe in the clay mineral structure. While the redox-activity of Fe in smectites has received quite some attention, other common types of clay minerals present in clay host rocks have received less attention. In this study we investigated redox capacities of a variety of common clay minerals using mediated electrochemistry. Results show that most clay minerals have electrochemically‑active Fe to some extent, but there is a large variation in the fractions of electrochemically-active Fe between the different clay minerals. Smectites had the highest redox-active Fe fraction (~100%), followed by mixed illite-smectite (~40%), glauconite (~15%), illite (~10%) and chlorite (~1%). Within the same clay mineral type there was also variation in the redox-active fraction. Batch experiments showed that even for clay minerals in which only a small fraction of Fe was redox-active, reduction of selenite to elemental selenium took place.
Interlaboratory Calibration for Laser Ablation of Ice Cores
Authors: Gadrani Lela , Kurbatov Andrei V. , Korotkikh Elena , Bohleber Pascal , Mayewski Paul A. , Handley Michael
Published: February 2023

We report interlaboratory comparisons of a methodology to measure and calculate concentrations of impurities in ice core samples using the Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) system developed at the W. M. Keck Laser Ice Facility at the Climate Change Institute, University of Maine (UMaine). Here, we will summarize results of measured artificial samples with known levels of  Ca, Al, Fe, Mg, Na, Cu, Pb. We adapted a method for LA-ICP-MS analysis of the frozen standard that was developed in the laboratory at Ca’ Foscari University of Venice, and we tested its applicability to the UMaine system. This work will help to measure and interpret very old and highly compressed ice core records from the Allan Hills Blue Ice Area, Antarctica, sampled with different analytical tools.  
Geomorphological-geological characterization of an active, deep-seated rockslide in a heavily foliated rock mass – Wasserradkopf, Austria
Authors: Simma Severin , Gerstner Reinhard , Valentin Gerald , Goldschmidt Franz , Zangerl Christian
Published: February 2023

We present a study focusing on the geologic-geometrical characterization of an approximately1,5 km² large, deep-seated rock slide at the south-eastern slope of the Wasserradkopf (3032m a.s.l.) located in the high alpine environment of the Hohe Tauern National Park (Carinthia,Austria). The rocks composing the Wasserradkopf belong to the “Bündnerschiefer”, whichmainly consist of a highly schistose rock mass.Within our study, we performed a lithological and structural characterization, detailly mappedthe geomorphological features, and incorporated high resolution INSAR data in order todemonstrate the structural control on the rock slide process.Firstly, we conducted a geological field survey with the aim of creating a geological map of thestudy site. Petrographic investigations on the microscope helped to classify the mappedlithologies according to their mineralogy. Additionally, we recorded discontinuities to identifythe structural inventory of the rock mass hosting the rock slide allocate the discontinuities todiscontinuity sets.Secondly, we characterized and mapped the geomorphological features, i.e., scarps, counterfacing scarps and horst and graben structures on the rock slide surface to identify the unstableareas and distinguish individual rock slide slabs.Finally, we assessed the INSAR data to quantify the movement in the outlined unstable areas.By mapping areas of differential deformation rates, we confirm the presence of individual rockslide slabs.The preliminary results show that dominant brittle structures, which are represented by twosubvertical NNE-SSW and WNW-ESE striking joint sets, and several NE-SW striking steepstanding faults provide a favorable structural predisposition in interplay with the moderatelyout-slope dipping schistosity for a rock slide mechanism to develop. Moreover, we correlatethe differential movement rates observable in the INSAR data with the individual rock slideslabs identified by geomorphologic mapping.By this combination of geological, geomorphological and advanced remote sensing techniqueswe demonstrate the structural influence on the rock slide process and unravel its internaldeformation and kinematics.
Borehole thermal energy storage (BTES) as backup systems in district heating and cooling contexts: results from numerical simulations
Authors: Chicco Jessica , Mandrone Giuseppe
Published: February 2023

The current energy crisis since February 2022, have led governments to put in place short and long-term measures aimed at shielding consumers from the direct impact of the rising energy prices across Europe, and to counteract the continuous economic volatility. The pressure is high for finding solutions to reduce energy imports, and fight against climate change impacts. The numerous debates on climate change such as the COP27 are pushing for a greater acceleration in decarbonising the energy sector. Low carbon sources such as geothermal energy can substantially decrease energy consumptions and costs, especially if included into decarbonized heating and cooling grids (Chicco et al., 2022). The use of geothermal energy for thermal energy production and storage in district heating and cooling (DHC) grids may also be a key element in overcoming short-term energy peaks overcoming of the gap between energy supply and demand, which is still a challenge for the energy transition.  In this framework, underground thermal energy Storage (UTES) systems can be a key element for efficient operation of heating and cooling grids. Here, we present a study aimed at evaluating the performance of one of the most promising underground thermal energy storage systems, which uses boreholes to store heat or cold (BTES). Aimed at testifying the replicability of the used methodology, we replicated the same workflow already presented in Chicco and Mandrone (2022) but on a different area in northern Italy, with similar hydrogeological and thermo-physical characteristics. Based on real field data, the study focused on numerical simulations aimed at understanding how these technologies can be used as backup systems, or when the energy demand overcomes that supplied by conventional heating systems. Obtained results proved again how the integration of these technologies in DHC contexts can contribute to greater energy and economic savings, showing that BTES are very flexible to meet both the base and peak load requests for several users.Chicco, J.M.; Antonijevic, D.; Bloemendal, M.; Cecinato, F.; Goetzl, G.; Hajto, M.; Hartog, N.; Mandrone, G.; Vacha, D.; Vardon, P.J. Improving the Efficiency of District Heating and Cooling Using a Geothermal Technology: Underground Thermal Energy Storage (UTES). In New Metropolitan Perspectives; Calabrò, F., Della Spina, L., Piñeira Mantiñán, M.J., Eds.; NMP 2022; Lecture Notes in Networks and Systems; Springer: Cham, Switzerland, 2022, 482, 1699–1710. https://doi.org/10.1007/978-3-031-06825-6_164Chicco, J.M.; Mandrone, G. Modelling the Energy Production of a Borehole Thermal Energy Storage (BTES) System. Energies 2022, 15, 9587. https://doi.org/10.3390/en15249587
The April 2022 South Africa Flood event
Authors: Scudeler Carlotta , Giani Giulia , Tsioulou Alexandra
Published: February 2023

Over April 2022, heavy rain in KwaZulu-Natal province in South Africa, followed by intense flooding and mudslides, caused one of the deadliest natural disasters in the country, mostly hard-hitting the areas in and around Durban. The intense rainfall was caused by a cut-of-low mid-latitude depression, known as Storm Issa, which is a common weather system in South Africa, particularly in the spring and summer months. In this study we present an analysis which investigates 1) the reasons why this event has been so impactful in terms of damage and loss compared to other similar events in South Africa and 2) if the intensity and frequency of such a storm is increasing as a result of a changing climate.  The analysis has been carried out at different levels: ERA-5 reanalysis data and rain gauge data have been used to characterize at different temporal and spatial scales the precipitation relative to the event and compared to other similar events; DWS discharge data have been used to analyse the event in terms of hydrological response and flow; and finally the footprint of the event has been reconstructed, following the flow analysis and by means of UNOSAT satellite-detected flood, landslide and damaged structures taken as reference. Among the major outcomes of the analysis we found that the duration and antecedent conditions, most probably also exacerbated by La Nina effect, made the event exceptional, resulting in a flash flood among the highest recorded in the last 70 years. The reconstructed event footprint whilst could be improved in the areas which were mostly affected by landslides, captures well the flooding in the major floodplain.     
Influence of enhanced silicate weathering on microbial processes and soil carbon formation in agricultural soil
Authors: Sohng Jaeeun , Holzer Iris , Goertzen Heath , Schmidt Radomir , Scow Kate
Published: February 2023

Enhanced silicate weathering (ESW) is an innovative technique to leverage natural processes which usually operate over millions of years to potentially replenish nutrients and carbon (C) in soil. ESW involves applying pulverized silicates to increase reactive mineral surfaces which in turn may speed-up the weathering and scale to aid in global CO2 removal. However, current studies supporting ESW has been relying on theoretical estimates and short-term laboratory experiments whose results are difficult to extrapolate to the field. Also, many studies have focused on inorganic C chemistry while soil is a rich medium that mediates a multitude of chemical and biological processes, many of which are not well studied but may play an important role in controlling ESW. To address this gap, the Working Lands Innovation Center (WLIC) Project was launched in 2019 for a field scale test, and three commercial amendments (compost, biochar, and silicate powder—meta-basalt) have been applied yearly with a full factorial design in a 2.07 ha corn field at the Campbell Tract research facility located on the UC Davis campus. My project within WLIC evaluates the impact of ESW on soil surface C pools related to microbial processes and its potential synergies with traditional organic amendments. We hypothesized that co-applying organic amendments plus pulverized silicate minerals will: 1) increase microbial biomass with distinct microbial community composition; and 2) increase the formation of stable carbon pools (e.g., mineral associated organic matter) relative to only silicate applied soil. To test this, we sampled soils from all possible amendment combinations at pre-, and post-harvesting seasons in 2021 and 2022. We completed a suite of analyses to monitor temporal changes of soil chemistry, multiple C pool sizes, and microbial parameters. Here, we will examine the causal mechanisms that explain how adding extra C with silicates may change microbial environments and carbon pool dynamics over a two-year period. Our findings will provide critical information whether natural soil processes, such as rock weathering and soil organic C stabilization, can be engineered (and accelerated) for management purposes at agricultural field scale.
Novel Directional Steel Shot Drilling Technology for Short-Radius Multilaterals – Field Application and Commercial Impact
Authors: Reinicke Andreas , Deb Paromita , Saar Martin O. , Zikovic, V. Vedran , Lassnig Erich , Knebel Marcel , Blangé Jan Jette
Published: February 2023

Reliable delivery of economic well performance of geothermal projects is affected to a high degree by uncertain reservoir quality. Construction of multilateral wells is well known as an effective concept to overcome the challenges of reservoir heterogeneity or low permeability by increasing the reservoir contact. However, the drilling costs for these structures are currently very high and multilateral well construction with standard rotary steerable systems is complex. Canopus’ directional steel shot drilling system (DSSD) has the potential to enable the construction of short-radius multilaterals at rates attractive for geothermal applications.As part of the European GEOTHERMICA project ‘DEPLOI the HEAT’, the operational performance and economic impact of Canopus’ DSSD system will be investigated. Full-scale tests at TNO’s Rijswijk Centre for Sustainable Geo-Energy (RCSG) and a field trial at the Hagerbach underground test facility (VSH) are planned for the first project year. The RCSG drilling rig enables full factory acceptance testing (FAT) of the drilling assembly before the trial at the VSH site is executed. The geology at the VSH site reflects conditions of typical mid-depth fractured limestone reservoirs in Switzerland and elsewhere. At VSH, a complete set of operational parameters and system longevity will be tested with a full-scale trial to prepare for live well deployment.Further, a techno-economic assessment of multilateral structures drilled with Canopus’ DSSD system will highlight the potential for increasing or safe-guarding well productivity and economically de-risking geothermal projects. Several operators are involved in this project and the techno-economic assessment of the drilling technology will be based on several site-specific data sets provided by them. Stochastic modeling approaches will be implemented to generate an ensemble of equally probable realizations of permeable structures in the subsurface. Then, the performance and costs of different well geometries and multilateral configurations in different subsurface model realizations will be evaluated and compared.The current status of this project will be presented with a focus on the factory acceptance testing at TNO, the VSH trial preparations and the workflow developed for the techno-economic assessment of this innovative multilateral drilling technology.
Overview of aerosol observations from the Marion Dufresne Atmospheric Program – Indian Ocean (MAP-IO) program
Authors: Dournaux Meredith , Tulet Pierre , Pianezze Joris , Sellegri Karine , Brioude Jérôme
Published: February 2023

The study of marine aerosols size distribution and cloud condensation nuclei (CCN) properties is of major interest as they influence clouds life and clouds radiative properties, particularly in the remote ocean which remains poorly documented. Several short campaigns focusing on specific regions as phytoplankton bloom regions, pristine regions or remote areas influenced by continental air masses took place to address this issue. However, long sampling periods targeting different in-situ conditions had not been realized.
In this context, the MAP-IO program was launched with the aim of providing a large new set of marine aerosol observations (size distribution from 10 nm to 10 µm and CCN properties) on different sea state and meteorological conditions. Thus, the Marion Dufresne vessel has been equipped with a set of various instruments described in Tulet et al. (in preparation) or on the website www.mapio.re. Two years after the launch of the program, we now have aerosol observations (about 200 days) over an area covering 50 ° of latitudes and extending from the Tropics to the upper Southern Ocean. 
These measurements were first used to investigate the size distribution and CCN variability of marine aerosols according to local conditions (sea states and wind speed).The results highlight that at the lowest latitudes (south of 50 °S) the minimum concentration of CCN tends to increase when the wind speed exceeds approximately 12 m s-1, which is consistent with the literature as sea salt  emissions are mechanically driven by local conditions and tend to be predominant from 10 m s-1. .When analyzing the size distributions of aerosols according to the wind speed during a 5-day storm that occurred in the Southern Ocean, we found that: (1) the number of particles with a diameter less than 500 nm is predominant and stable over the full range of wind speeds (4 to 33 m s-1), (2) the number of aerosols with diameter greater than 500 nm remains low under 10 m s-1 and increases from 10 m s-1 to 33 m s-1 to finally reach the concentration of the particles with diameter less than 500 nm at 33 m s-1. 
Taking this first analysis into account, further work will focus on average size distributions per region, season, origin of air masses (from simulated FLEXPART back trajectories) and wind speed conditions. Analysis of these distributions is unique due to the size of the database, the variability of regions encountered and knowing that the measurements were carried out with the same experimental device. 
 Finally, to deepen the study, the activation diameter of marine aerosols will be determined and the hygroscopicity parameter Kappa-Köhler will be calculated (Petters and Kreidenweis, 2007) in this case to distinguish sea salts (Kappa~1.2) from organic matter (0.01<Kappa<0.5).
Updating annual rainfall maxima statistics in a data-scarce region
Authors: Avino Angelo , Cimorelli Luigi , Pianese Domenico , Manfreda Salvatore
Published: February 2023

The growing number of extreme hydrological events observed has raised the level of attention toward the impact of climate change on rainfall process, which is difficult to quantify given its strong spatial and temporal heterogeneity. Therefore, the impact of the climate cannot be determined on the individual hydrological series but must be assessed on a regional and/or district scale. With this objective, the present work aims at identifying the trends and dynamics of extreme sub-daily rainfall in southern Italy in the period 1970-2020. The database of annual maxima was assembled using all available rainfall data (provided by the National Hydrographic and Mareographic Service - SIMN, and the Regional Civil Protection). However, due to the numerous changes (location, type of sensor, managing agencies) experienced by the national monitoring network, the time-series were found to be extremely uneven and fragmented. Since the spatio-temporal discontinuity could invalidate any statistical analysis, gap-filling techniques (deterministic and/or geostatistical [Teegavarapu, 2009]) were applied to reconstruct the missing data. In particular, the “Spatially-Constrained Ordinary Kriging” (SC-OK) method [Avino et al., 2021] was used, namely a mixed procedure that adopts the Ordinary Kriging (OK) approach with the spatial constraints of the Inverse Distance Weighting (IDW) method. The SC-OK method allows to reconstruct only missing data for stations selected by the IDW method (those with a sufficient number of functioning neighbouring rain gauges). Then, the reconstructed dataset has been used to explore trends and regional patterns in annual maxima highlighting, how rainfall are evolving in the most recent years.REFERENCESAvino, A., Manfreda, S., Cimorelli, L., and Pianese, D. (2021). Trend of annual maximum rainfall in Campania region (Southern Italy). Hydrological Processes, 35.Teegavarapu, R.S.V. (2009). Estimation of Missing Precipitation Records Integrating Surface Interpolation Techniques and Spatio-temporal Association Rules. Journal of Hydroinformatics, 11(2).
Introducing the French national programme TRACCS: TRAnsformative Advances in Climate modelling for Climate Services
Authors: Kageyama Masa , Morin Samuel , Anquetin Sandrine , de Noblet Nathalie , Terray Laurent , Boucher Olivier , Deshayes Julie , Durand Gaël , Salas y Mélia David , Bouilloud Ludovic , Braconnot Pascale
Published: February 2023

TRACCS (TRAnsformative Advances in Climate modelling for Climate Services) is a new French programme which will start in 2023 and run for the next eight years. TRACCS will combine several types of activities: i) process modelling for simulating climate from global to local scales, so as to provide reliable climate information for assessing both mitigation scenarios and local adaptation actions and their feedback effects on the climate, ii) adaptation of computer codes to new computing architectures, to seize the opportunities offered by exascale in terms of increasing spatial resolution, better representing the complexity of the climate system, and exploring large sets of simulations and obtain better information on model and scenario-related uncertainties, iii) the use of advanced statistical methods and artificial intelligence to characterise climate extremes, accelerate models, and develop emulators (fast statistical models) to better quantify uncertainties, iv) the estimation of the impacts of climate change on different activity sectors and different territories in order to co-construct adaptation, and v) the development of a dialogue between scientists and stakeholders, teaching and communication with all audiences in order to co-construct prototypes of climate services in a transdisciplinary approach. These activities, together with the training of a new generation of experts in climate change and its impacts, have the ambition to transform the way scientific advances on climate change are shared with stakeholders, thereby multiplying the capacity for science-based adaptation and mitigation.The programme is jointly managed by CNRS and Meteo-France and involves key partners (CEA, IRD, CERFACS, Université-Grenoble-Alpes, Sorbonne Université, Université Versailles-Saint-Quentin, Université Paris-Saclay) in modelling and understanding climate change and its potential impacts.Our poster presentation will give us an opportunity to present this new project and build collaborations with similar projects at the European and international level.
Geospatial modeling for evaluating restoration suitability of Posidonia oceanica meadows offshore Civitavecchia (eastern Tyrrhenian margin, Mediterranean Sea)
Authors: Savini Alessandra , Varzi Andrea Giulia , Marino Luca , Fersini Giorgio , Piazzolla Daniele , Scanu Sergio , Marcelli Marco
Published: February 2023

Marine ecosystem restoration actions are becoming increasingly more popular in many areas of the world, representing one of the greatest challenges to date that can deliver results in line with the UN 2030 Agenda for Sustainable Development. However, their success rate is highly variable and depends mainly on the specific biological and ecological characteristics of the species involved, their ecosystem functioning, and undoubtedly on how, where and when restoration is conducted. Knowledge about the factors that enhance or limit the success of restoration efforts, with respect to a given habitat is, to date, very limited for the marine environment. Different sensitivity to human pressures and the spatial variability in the ecological variables that determine their presence and distribution are undoubtedly key factors, and it is therefore necessary to provide detailed and focused information on the selection of restoration sites and methods, from which successful and sustainable restoration actions depend. The national RENOVATE project (ecosystemic appRoach to the EvaluatioN and testing of cOmpensation and mitigation actions in the marine enVironment: the cAse of the civiTavEcchia harbuor), coordinated by CMCC (Mediterranean Centre for the study of Climate Changes) and funded by “AdSP (Autorità di SIstema Portuale) of the north-central Tyrrhenian Sea” is performing an integrated methodology for the compensation of Mediterranean marine ecosystems, damaged by anthropogenic impacts, in selected areas located offshore Civitavecchia harbor, where port expansion activities will soon be started. In this context, the present work focuses on providing a high resolution mapping of Posidonia oceanica meadows within the targeted project areas and introduces a new approach, based on the application of geospatial modeling techniques, to perform a semi-automatic detection of appropriate restoration sites. The proposed work flow is based on performing quantitative analysis of acoustic remote sensing data (i.e. Multibeam bathymetry and side-scan sonar backscatter intensity) applying Object-Based Image Analysis (OBIA) techniques, and ad-hoc developed numeric modeling. Our major goal was to classify seafloor suitability for restoration actions, according to variation in landscape spatial arrangement of P. oceanica meadows (determined by type of lower and upper limit, type of seagrass bed morphology, meadow patchiness, etc), quantified through the morphometric characterization of their geospatial configuration and architecture, and the operational depth for planned seagrass implantation strategy. Our work attempts to contribute to the development of efficient methodologies for the detection of suitable restoration sites that can support long-term growth and survival of P. oceanica meadows.
Quantifying carbon cycle feedbacks to past hyperthermal events
Authors: Greene Sarah , Jones Stephen , Adloff Markus , Doherty Daniel , Ridgwell Andy
Published: February 2023

The magnitude of future climate change depends on how Earth's natural carbon reservoirs respond to the changing climate via carbon cycle feedbacks. Yet many of these feedbacks are poorly constrained and are widely acknowledged as a major source of uncertainty in climate projections, particularly into the long-term future. Whilst we can measure carbon cycle feedbacks over the historical period, the future pacing and strength of carbon cycle feedbacks remains uncertain. We do not yet know whether they will collectively amplify or dampen anthropogenic climate change in future or whether carbon cycle tipping point events will be triggered, releasing geologically sequestered carbon to the ocean-atmosphere. Hyperthermal events can serve as partial analogues to anthropogenic climate change and allow us to better constrain carbon cycle behaviour in response to global warming. However, most sedimentary proxy records of hyperthermals at the Earth’s surface record the net environmental change caused by both an initial ‘forcing’ and all subsequent ‘feedbacks’ to that forcing. Disentangling forcing and feedbacks signals across hyperthermals requires further independent constraints on some aspect of the system. The geological record is peppered with examples of past carbon emissions events from large igneous province (LIP) activity, many of which coincide with mass extinction and/or hyperthermal events. Here we show how carbon emissions from a large igneous province (the North Atlantic Igneous Province or NAIP) can be constrained at high resolution entirely independently from environmental proxy records. We further show how an Earth system modelling approach comparing NAIP carbon emissions predictions with proxy records of the Paleocene-Eocene Thermal Maximum (PETM, ~56 Ma) can be employed to constrain net global carbon cycle feedbacks to NAIP carbon emissions. Lastly, we show how the addition of carbon and trace metal isotope systems in this Earth system modelling framework has the potential to allow us to disentangle individual global carbon cycle feedbacks across events like the PETM, ‘fingerprinting’ the carbon reservoirs and quantifying their response to a known exogenic carbon input.
Modelling approaches for atmospheric ion-dipole collisions: all-atom trajectory simulations and central field methods
Authors: Neefjes Ivo , Halonen Roope , Vehkamäki Hanna , Reischl Bernhard
Published: February 2023

Collisions between ions and dipolar molecules can facilitate the formation of atmospheric aerosol particles and play an important role in their detection in chemical ionization mass spectrometers. Conventionally, analytical models or simple parametrizations have been used to calculate rate coefficients of ion-dipole collisions in the gas phase. Such models, however, neglect the atomistic structure and charge distribution of the collision partners.         To determine the accuracy and applicability of these theoretical approaches, we calculated collision cross sections and rate coefficients from all-atom molecular dynamics collision trajectory simulations, sampling a relevant range of impact parameters and relative velocities, and from a central field model using an effective attractive interaction fitted to the long-range potential of mean force between the collision partners. We considered collisions between various atmospherically relevant molecular ions and dipoles, as well as charged and neutral dipolar clusters.         We find excellent agreement between the collision cross sections and rate coefficients obtained from the molecular dynamics trajectory simulations and the central field model. Therefore, we conclude that the effective interactions between the collision partners are highly isotropic, and the central field model is able to capture the relevant physicochemical properties of the system.         Comparing the molecular dynamics trajectory simulations with the often-used parametrization by Su and Chesnavich (1982), we find that the latter can predict the collision rate coefficient quite well for systems with a molecular dipole, but the agreement worsens for systems with a dipolar cluster.         Based on our results, we propose the combination of potential of mean force calculation and central field model as a viable and elegant alternative to brute force sampling of individual collision trajectories over a large range of impact parameters and relative velocities.         We are currently using the combination of potential of mean force calculation and central field model, as well as the atomistic trajectory simulations, to understand the relatively large increase in rate coefficient observed in chemical ionization mass spectrometers when sulfuric acid is charged with acetate, as compared to nitrate (Fomete, 2022). Su, T. and Chesnavich, W. J.: J. Chem. Phys. 76, 5183–5185, 1982.Fomete. S. et al.: J. Phys. Chem. A 126, 44, 8240–8248, 2022.
Modelling plant-mycorrhizae interactions - a review
Authors: Forsberg Malin , Wild Birgit , Manzoni Stefano
Published: February 2023

Symbiotic associations between plants and soil microbes, especially mycorrhizal fungi, are fundamental for plant nutrition and belowground processes associated with carbon (C) transfer from plants to the rhizosphere and mycorrhizae are key components of the global carbon cycle. Plants sacrifice photosynthetically acquired C in exchange for nutrients from their symbiotic partner. This exchange can be advantageous when mycorrhizae can access nutrient pools that plants cannot reach—either because chemically recalcitrant (e.g., nutrients in organic matter), or physically isolated (hyphae explore soils more effectively than roots). Additionally, the mycorrhizal network can extend into great distance and allows plants to share C and nutrients. Therefore, understanding this relationship and the interactions between plants and soil microbes are vital for creating realistic predictions of C and nutrient cycling in forests.In this contribution, we review current modelling approaches to plant-mycorrhizae processes and pathways, focusing on C and nutrient cycling, to highlight ongoing trends and knowledge gaps. It is evident that further model-development is needed in order to get accurate predictions. Some models include C and nutrient exchanges between plants and mycorrhizae via empirical factors, lacking a process-based description of these exchanges. Other models describe C-nutrient exchanges based on stoichiometric demand and supply of C and nutrients, possibly resulting in excessively constrained exchanges. The approaches that quantify costs and benefits of symbiosis in an eco-evolutionary framework are promising as they capture adaptation mechanisms. In general, models tend to focus more on stoichiometry than on temperature and soil moisture effects on plant-mycorrhizae interactions. Information about how the soil-plant system reacts to changes with climate dependent environmental conditions are also underrepresented. Therefore, while coupled plant-mycorrhiza models have been tremendously improved in recent years, they might still not fully capture the role of mycorrhizae in the C and nutrient cycling in terrestrial ecosystems.
CMIP6 multi-model projections of the groundwater response to climate change during the 21st century
Authors: Costantini Maya , Colin Jeanne , Decharme Bertrand
Published: February 2023

Climate change will impact every component of the climate system and water cycle. It does not spare groundwater which account for approximately one third of the human fresh water withdrawals. The combined effect of climate change and groundwater pumping could lead to water scarcity and food insecurity in some regions. Therefore, it is essential to study the groundwater response to climate change to improve the development of adaptation and mitigation plans in water management.Here, we analyze the response of groundwater recharge to climate change using an ensemble of simulations runs with 22 fully coupled ocean-atmosphere-land models participating to the CMIP6 exercise. They are run from 1850 to 2100 and follow four of the latest IPCC scenarios of greenhouse gas future evolution. This analysis is supplemented with the assessment of the climate-driven response of groundwater level given by the CNRM global climate models (which are part of the CMIP6 exercise). These models represent the hydrogeological processes involving groundwater, including the two-way water exchanges with rivers and the unsaturated soil, the lateral groundwater fluxes, and the interactions with the atmosphere. Results show that on global average, groundwater recharge is expected to increase with climate change. The changes in groundwater recharge follow those of precipitation and, to a lesser extent, evapotranspiration and thus follow the same regional patterns. As these CMIP6 models do not represent human groundwater withdrawals, the projected changes in recharge are somewhat optimistic and could be out of step in regions with strong groundwater pumping. To address this limitation, results are put in perspective with projections of water withdrawals following the CMIP6 experiments. This analysis shows the combined effects of climate change and groundwater pumping on groundwater and help to understand the evolution of the future large scale water resource.
Effect of transient deformation in southeast Greenland
Authors: Barletta Valentina R. , Bordoni Andrea , Khan Shfaqat Abbas
Published: February 2023

Recent studies have shown that in the area of the Kangerlussuaq glacier, a large GPS velocities residual after removing predicted purely elastic deformations caused by present-day ice loss suggests the possibility of a fast rebound to little ice age (LIA) deglaciation. We previously investigated this area with a Maxwell viscoelastic rheology Earth model and compared the model predictions with GPS residual. We found a match for a rather thick lithospheric thickness and a rather low mantle viscosity structure beneath SE-Greenland. In this study we are going to examine the effect of a Burger model: 1) we compare the results with those from the Maxwell model and 2) we estimate if and where the differences can be discriminated with observational data.Maxwell models describe a steady state mantle deformation and they are the most commonly model used in post glacial rebound problems. Burgers models, instead, describe a time-varying mantle deformation, which include an initial fast transient components followed by a steady-state phase of mantle deformation. This kind of transient deformation would allow to reconcile the Earth rebound caused by the Pleistocene deglaciation and the faster rebound caused by the recent LIA deglaciation.We then analyze several scenarios of ice retreat in the last 2000 years in the fiord in front of Kangerlussuaq glacier, in view of the difference between the two rheologies.
Inferring the scaling of the Earth system response to past periods of global warming
Authors: Cramwinckel Marlow Julius
Published: February 2023

Periods of warming in the geological past provide evidence of the Earth system response to increased temperatures. Global warming has occurred at different rates and amplitudes, and the full set of these different natural experiments can be leveraged to extrapolate and predict the Earth’s systematic environmental and ecological response to present-day climate change. Especially the perturbations of the Eocene hothouse world (56–34 million years ago) provide useful analogues under an already warm background state. Here, I will focus on comparing and contrasting the Earth system response to global change during the Middle Eocene Climatic Optimum (MECO; ~40 million years ago) with the Paleocene-Eocene Thermal Maximum (PETM; ~56 million years ago). Warming during the MECO was about an order of magnitude slower and several degrees Celsius less than during the PETM. Moreover, it is likely that different destabilizing carbon cycle feedbacks were involved as causal forcing to these events. Although it seems that similar responses occurred – including ocean deoxygenation and stratification, turnover in marine and terrestrial biotic communities, poleward migration of species – reconstructions show the MECO was characterised by less severe environmental and biotic change. Using the MECO and PETM as main template, I will assess if we can use past periods of warming to infer scaling dynamics and potentially non-linearities in the consequences of past and future greenhouse-gas driven global change.  
How does the geographic location and pest management strategies impacts the geochemical fingerprint of leaves and olives in olive growing systems?
Authors: Medoro Valeria , Ferretti Giacomo , Galamini Giulio , Rotondi Annalisa , Morrone Lucia , Faccini Barbara , Coltorti Massimo
Published: February 2023

Recently, the demand for quality and food safety has become more pressing, with a consequent requirement for unequivocal geographical identification of agri-food products. Moreover, the requirement for eco-friendly and human healthy practices is a key issue for the agriculture of the future. In this framework, this work aims at investigating soil, leaves and olives from two areas in the Emilia-Romagna Region (Italy), Montiano (MN) and San Lazzaro (SL), where three different foliar treatments were carried out for each site to protect plants from environmental stress and pests. Geochemical analysis of REE and trace elements were performed to 1) univocally determine the locality of provenance and 2) evaluate if the different foliar treatments can affect the geochemical fingerprint of leaves and olives. the effect of different foliar treatments (no treatment, dimethoate, and alternating of natural zeolitite and dimethoate in MN; Spinosad+Spyntor fly, natural zeolitite and NH4+-enriched zeolitite in SL). Principal Component Analysis (PCA) and Partial Least Square-Discriminant Analysis (PLS-DA, including Variable Importance in the Projection analysis) were used to discriminate between localities and different treatments. PCA of leaves and olives highlighted that different foliar treatments can be identified based on different geochemical contents (total variance: 95.64% and 91.08% in MN; 71.31% and 85.33% in SL of leaves and olives, respectively). Slightly lower, although still quite acceptable, results are given by PCA applied to area discrimination (87.46% and 80.43% of total variance). The PLS-DA analysis gave the largest contribution to the discrimination of different treatments and geographical identification. VIP analyses provided to identify which elements could be considered as potential discriminators in the model in order to correlate leaves and olives from the same area: i) Sm and Dy in MN site and ii) Rb, Zr, La and Th in SL field; in order to discriminate different areas Rb and Sr were the best identifiers. Based on REE and trace element analyses, it can be highlighted that 1) the geographical origin could be discriminated and 2) different foliar treatments applied for crop protection can be recognized, which means, reversing the reasoning that each farmer can develop a method to pinpoint his own product.
Determination of the spatial scaling relationship of rainfall extremes using radar data
Authors: Goshtsasbpour Golbarg , Haberlandt@iww.uni-hannover.de Uwe , Sharma Ashish , El Hachem Abbas , Seidel Jochen , Bardossy Andras
Published: February 2023

Climate models and their future projections, are normally provided in coarse spatial resolutions which makes them an imprecise source of information for certain hydrological purposes. Finding the proficient means of downscaling such data is one of the open questions of climate research. Previous research has shown that, the rainfall extremes show self-similarity in time and that a relatively similar behavior exists in regard to the spatial scale as well (Veneziano et al 2002). This study aims at determining the spatial scaling relationship of the rainfall extremes by using fine grids of radar datasets and upscaling them. In an empirical manner by aggregating the radar rainfall cells in space and for different cell sizes with a = 1, 2, 3, …12 km and for different durations of d = 5 min, 15 min 30 min, 1 hr, 2 hr, 4 hr, …, 24 hr the Annual Maximum Series are extracted. Using the AMS of different spatial and temporal scales and applying the Koutsoyiannis et at. 1998 method for rainfall extreme value analysis, the probability distribution function is fitted. Assessing the changes of the PDF parameters with the scale, with a logarithmic transformation on both variables; ln(parameter) vs. ln(scale), can show the sought relationship. The preliminary results of the study show definable non-linear relationships for location and scale parameters of the GEV distribution and the eta parameter of the Koutsoyiannis et al. 1998 parametrization. Koutsoyiannis, D. Kozonis, and A. Manetas, A mathematical framework for studying rainfall intensity-duration-frequency relationships, Journal of Hydrology, 206 (1-2), 118–135, doi:10.1016/S0022-1694(98)00097-3, 1998.Veneziano, Daniele; Furcolo, Pierluigi (2002): Multifractality of rainfall and scaling of intensity-duration-frequency curves. In Water Resour. Res. 38 (12), 42-1-42-12. DOI: 10.1029/2001WR000372.