bluuebunny/crossref_metadata_2025 huggingface dataset:
Using the Vegetation Condition Index combined with time-series analysis to monitor the health of the Maltese vegetation in the context of sustainable tourism development
Authors: Poupard Hugo , Castel Fabien
Published: February 2023

Earth observation technologies can help tourism organizations to meet sustainable tourism development guidelines and management practices set by the World Tourism Organization, especially regarding the environmental dimension. In this context, the Malta Tourism Authority (MTA) is looking for an easy and reliable tool to assess vegetation health in order to monitor the impact of tourism on its environment. Based on this partnership, we chose to enhance the Vegetation Condition Index (VCI) using Sentinel-2 to assess the vegetation health of Malta from January 2017 to October 2022. This method consists of comparing the current NDVI values to the range of values observed in previous years. The VCI allows to determine where the observed value is situated between the extreme values (minimum and maximum). Lower and higher values are used as proxy to indicate the critical and optimal vegetation state conditions, respectively. We used the Seasonal and Trend decomposition using Loess to decompose the VCI time-series from three distinct vegetation types, namely cropland, grassland, and trees. This method uses locally fitted regression models to decompose a time series into trend, seasonal, and remainder components. Regarding vegetation health assessment of Malta, we noticed a period of drought in 2021 which was the result of a strong anomaly in October 2020. During this period, trees were the most affected type of vegetation. However, no correlation was found between tourists' inbound and vegetation health.We based our validation on the fact that meteorological conditions are the main factors for vegetation health variations. Thus, we used total precipitation, and surface temperature variables from the ERA5 climate reanalysis database (ECMWF) as proxy for ground-truth data. We found that precipitation was “Granger causing” (statistical hypothesis test for determining whether one time series is useful in forecasting another) VCI and that it was cross-correlated (using Spearman correlation method) with VCI at 0.80, whereas temperature was negatively correlated with VCI at -0.91 meaning that our hypothesis was correct. Ultimately, we combined the produced information into a dashboard in order to display the information for the end-user. This visualization combined three distinct dimensions of vegetation health, namely the temporal dimension which displays long-term time-series, the spatial dimension which displays VCI maps with vegetation highlight layers that help for spatial contextualization, and the trend dimension which combines trends of VCI and the influencing factors. 
Simulating rainfall and drainage response using CON-SST-RAIN - a stochastic areal rainfall generator
Authors: Andersen Christoffer B. , Thorndahl Søren , Wright Daniel B.
Published: February 2023

Stochastic rainfall generators have been commonly used in the field of hydrological and hydrodynamic modeling for a long time. These generators allow for an extensive ensemble of rainfall scenarios and continuous time series that is applicable for risk assessment and response variability studies under current and future climate conditions. Most rainfall generators simulate rainfall at daily scale and at point values. Recently some generators have been developed to produce gridded rainfall products. With advancement in weather radar technology a much more detailed representation of rainfall fields is now possible. This is especially needed in the field of urban hydrology.We developed the stochastic rainfall generator CON-SST-RAIN that is based on traditional dry/wet sequencing using Markov Chains and rainfall field generation by Stochastic Storm Transposition (SST), a time-in-space resampling method. CON-SST-RAIN was developed utilizing a 17-year long C-band radar dataset, with a spatio-temporal resolution of 500m x 500m and 10 minutes, discontinuous in time (discard of data) and Markov Chains are derived from rain gauges.CON-SST-RAIN can recreate continuous areal time series that captures the mean annual precipitation while also retaining seasonal and inter-annual variances. Extreme rain rates are likewise preserved and comparable to rain gauge data with +40 years of record.We test the CON-SST-RAIN on stochastically generated artificial hydrological networks to examine the importance of spatio-temporal dynamic rainfall fields. The networks are generated by a Gibbs sampling approach where the modeler can choose the extent and complexity of the generated network. Runoff from these networks is coupled with a simple detention pond model to estimate return periods for rainfall storage.
Spatial and temporal water table dynamic of a common alder riparian forest
Authors: Gribovszki Zoltán , Herceg András , Holik Blanka , Nevezi Csenge , Kalicz Péter , Bazsó Tamás , Brolly Gábor , Zagyvai-Kiss Katalin Anita
Published: February 2023

Forested riparian areas are valuable because they are rich in biodiversity and more productive than their adjacent upland areas, but they could be threatened by drought. The groundwater level of the riparian zone is an important parameter to quantify the forest hydrological processes thus for their survival. This study examines the influence of riparian zone groundwater level dynamics on the water balance of an alder forest. Our research area is a streamside alder ecosystem at the eastern foothills of the Alps, in Hidegvíz Valley (Hungary) experimental catchment. We analysed the water table dynamics in the period 2017-2022 using seven manually detected groundwater wells data. In the case of a selected well, we measured groundwater levels using an automatic pressure probe with high frequency. The related meteorological parameters were also collected in the immediate vicinity of the area.Using manually measured groundwater level data we found that in summer dry periods streamside water table fall below the level of the streambed causing the stream status changes from effluent to influent. Using high frequency water table data we analysed groundwater temporal dynamic and relationship with other environmental parameters seasonally. According to our calculations alder forest ecosystem groundwater transpiration is great in hot rainless periods. As a conclusion these riparian forest types can be characterised as a vulnerable ecosystem  in the changing climate because long dry periods will become more and more common in the future.Acknowledgement: This article was made in frame of the project TKP2021-NKTA-43 which has been implemented with the support provided by the Ministry of Innovation and Technology of Hungary (successor: Ministry of Culture and Innovation of Hungary) from the National Research, Development and Innovation Fund, financed under the TKP2021-NKTA funding scheme.
Development and testing of a modernised Programmable Ion Mobility Spectrometer
Authors: Aplin Karen , Meaney Alan , Bór József , Buzás Attila
Published: February 2023

The atmosphere is made slightly electrically conductive by cosmic rays and natural radioactivity, which generate ions. Air conductivity is a key component of the global electric circuit and influences droplet and cloud charging [1]. Further, atmospheric ions may affect the radiative balance through particle formation and infra-red absorption [2], [3]. Both considerations motivate the need for accurate atmospheric ion measurements. The Programmable Ion Mobility Spectrometer (PIMS) is a computer-controlled instrument based on the Gerdien measurement principle in which a cylindrical capacitor, across which a voltage is applied, is aspirated to sample air ions [4]. Computer control of a switchable multimode electrometer [5] offers the capability to measure ions in two modes, offering self-calibration, which removes the difficulties with providing a well-characterised environment for calibration [6]. The PIMS can independently monitor internal leakage currents which can be a significant source of thermally dependent error, especially in outdoor use. First developed in the early 2000s, the PIMS has recently been modernised with a new electrometer and advanced microcontroller, leading to significantly miniaturised electronics and opportunities for more sophisticated interfacing. The modernised PIMS was tested at Nagycenk Geophysical Observatory (47.632°N,16.718°E), Hungary in summer 2022, alongside a full range of meteorological and atmospheric electrical measurements for comparison. References[1]      R. G. Harrison and K. A. Nicoll, “The electricity of extensive layer clouds,” Weather, vol. 77, no. 11, pp. 379–383, Nov. 2022, doi: 10.1002/wea.4307.[2]      K. L. Aplin, “Composition and measurement of charged atmospheric clusters,” Space Sci Rev, vol. 137, no. 1–4, 2008, doi: 10.1007/s11214-008-9397-1.[3]      K. L. Aplin and M. Lockwood, “Cosmic ray modulation of infra-red radiation in the atmosphere,” Environmental Research Letters, vol. 8, no. 1, 2013, doi: 10.1088/1748-9326/8/1/015026.[4]      K. L. Aplin and R. G. Harrison, “A computer-controlled Gerdien atmospheric ion counter,” Review of Scientific Instruments, vol. 71, no. 8, 2000, doi: 10.1063/1.1305511.[5]      R. G. Harrison and K. L. Aplin, “Multimode electrometer for atmospheric ion measurements,” Review of Scientific Instruments, vol. 71, no. 12, 2000, doi: 10.1063/1.1327303.[6]      K. L. Aplin and R. G. Harrison, “A self-calibrating programable mobility spectrometer for atmospheric ion measurements,” Review of Scientific Instruments, vol. 72, no. 8, 2001, doi: 10.1063/1.1382634.
Dominant drivers of Past Mediterranean Marine Heatwaves
Authors: Darmaraki Sofia , Waldman Robin , Sevault Florence , Somot Samuel
Published: February 2023

The Mediterranean Sea, a global climate change hot-spot region, has experienced an increase in marine heatwave (MHW) frequency and intensity since the early 1990s. These extreme events have been associated with a range of local-ecological impacts in the basin, which hosts a large marine biodiversity in addition to 480 million inhabitants along its coasts. According to 21st century projections, the increasing MHW trends are likely to continue in the Mediterranean Sea. This calls for a deeper understanding of MHW drivers that can lead to a higher degree of MHW predictability. Therefore, this study investigates the dominant physical processes behind an ensemble of past Mediterranean MHWs, using the output of a dedicated, fully-coupled regional climate system model in hindcast mode, over the 1980-2018 period. In particular, we explore the vertical signature of multiple events in a local scale through “online” diagnostics of a mixed layer heat budget, where we disentangle the relative role of local-scale dynamics (e.g air-sea interactions, ocean currents, entrainment, mixing) during their development and decline. Preliminary results indicate a key role of atmosphere heat fluxes, wind forcing and vertical mixing on most events and a predominant horizontal advection presence only at smaller-scale. We present here a statistical overview of the dominant MHW drivers at the regional scale, across seasons and different regions in the Mediterranean basin, providing stakeholders and economy sectors affected by these marine extreme events, with critical information on their causes.
Reaction fronts in multi-component fluid-rock interaction using analytical solutions of the Gibbs minimization problem from Thermolab
Authors: Vrijmoed Johannes C. , Podladchikov Yury Y.
Published: February 2023

We study the systematics of reaction fronts in multi-component systems using Thermolab. The methodology is based on a finite difference approach for solving the transport problem in combination with lookup tables generated from precomputed thermodynamic equilibria covering the compositional space. The lookup tables generated from Gibbs minimization using linear programming combined with a discrete compound approach are validated against full analytical solutions of the Gibbs minimization problem. We focus on ternary ideal fluid or melt solutions in equilibrium with pure phases as exact solutions are feasible. We show that linear programming techniques yield similar results as a complete analytical solution and that both can be used in stable reactive transport codes.
Reconstruction of the evolution of the Osning Lineament in northern Germany using 2-D retrodeformation
Authors: Tanner David C. , Wadas Sonja H.
Published: February 2023

Neotectonic movements can cause severe geohazards and thus require examination for seismic hazard assessment, and utilisation of the subsurface for e.g. nuclear-waste disposal sites and geothermal exploitation. In northern Germany, very little is known about these processes and the associated structures, despite proven neotectonic activity, because many faults are hidden beneath sediments.The Osning Lineament (OL) in North Rhine-Westphalia is a recently-active fault zones. Three major earthquakes and seven other macro-seismic earthquakes occurred at the OL during the last 400 years. The strongest earthquakes occurred in 1612, 1767, and 1770, with an estimated intensity of VI to VII on the MSK scale. The OL is a unique fault system compared to other faults in northern Germany. The faults of the OL reach the basement, whereas in the north of the Lower Saxony Basin, most faults are decoupled from the basement by salt. Furthermore, the OL dips to the northeast and therefore the vector of the fault plane points towards the former iceload from Scandinavia, enabling glacial isostatic adjustment to occur on the faults. Additionally, the OL has had a history of multiphase reactivation in the geological past.To better understand the neotectonic evolution of the OL on a regional scale, we carried out a 2D retrodeformation using already existing large-scale cross sections along the lineament, which are based on surface geological maps and sparse drilling information. Balancing of these cross-sections verifies whether the fault geometry and kinematics derived from surface data are justified or need to be revised. Retrodeformation is also used to suggest the path of the fault(s) at greater (seismogenic) depth. Later on, retrodeformation will also be performed including new, highly-detailed seismic profiles and a joint interpretation will be carried out to improve the understanding of the past evolution of the Osning Lineament.
Simulation Study for Precise Orbit Determination of a Callisto Orbiter and Geodetic Parameter Recovery
Authors: Desprats William , Arnold Daniel , Bertone Stefano , Blanc Michel , Jäggi Adrian , Li Lei , Li Mingtao , Witasse Olivier
Published: February 2023

Callisto, the outermost of the four Galilean satellites, is identified as a key body to answer present questions about the origin and the formation of the Jovian system. Callisto appears to be the least differentiated and the geologically least evolved of the Galilean satellites, and therefore the one best reflecting the early ages of the Jovian system.While the ESA JUICE mission plans several flybys of Callisto, an orbiter would allow it to measure geodetic parameters to much higher resolution, as it was suggested by several recent mission proposals,e.g., the Tianwen-4 (China National Space Administration) and MAGIC (Magnetics, Altimetry, Gravity, and Imaging of Callisto) proposals. Recovering parameters such as those describing Callisto’s gravity field, its tidal Love numbers, and its orientation in space would help to significantly constrain Callisto’s interior structure models, including the characterization of a potential subsurface ocean.We perform a closed-loop simulation of spacecraft tracking, altimetry, and accelerometer data of a high inclination, low altitude orbiter, which we then use for the recovery of its precise orbit and of Callisto’s geodetic parameters. We compare our sensitivity and uncertainty results to previous covariance analyses. We estimate geodetic parameters, such as gravity field, rotation, and orientation parameters and the k2 tidal Love number, based on radio tracking (2-way Doppler) residuals. We consider several ways to mitigate the mismodeling of non-gravitational accelerations, such as using empirical accelerations and pseudo stochastic pulses, and we evaluate the benefits of an on-board accelerometer.We also investigate the added value of laser altimeter measurements to enable the use of altimetry crossovers to improve orbit determination and gravity-related geodetic parameters, but also to estimate the recovery of surface tidal variations (via the h2 Love number). For our closed-loop analyses, we use both a development version of the Bernese GNSS Software and the open-source pyXover software.
Variability in ENSO-induced carbon flux patterns
Authors: Dunkl István , Ilyina Tatiana
Published: February 2023

El Niño-Southern Oscillation (ENSO) is not only a driver of global carbon cycle variability, but it also provides several mechanisms of predictability. Although most Earth system models (ESMs) can reproduce the relationship between ENSO and atmospheric CO2 concentrations, the question remains whether the ESMs agree on the origins of these ENSO-related GPP anomalies. We analyse the patterns of ENSO-induced GPP anomalies in 17 ESMs to determine from which regions these GPP anomalies come from, and whether the differences among the models are driven by climate forcing or biochemistry. While most of the GPP anomalies originate from Southeast Asia and northern South America, there are large deviations among the ESMs. The combined GPP anomaly of these two regions ranges between 26% and 75% of the global anomaly among the ESMs. To find out what causes the differences, we examined two major drivers of the GPP anomalies: the size of the ENSO-induced climate anomalies, and the sensitivity of GPP to climate. On the global average, ENSO-induced climate anomalies and GPP sensitivity have similar uncertainty among the ESMs, contributing equally to the variations in ENSO-induced GPP anomaly patterns. This analysis reveals model biases in teleconnection patterns and biochemistry. Addressing these biases is a tangible goal for model developers to decrease the uncertainty in the reproduction of the global carbon cycle, and to increase its predictability.
Towards an Operational Earthquake Forecasting Model for Europe
Authors: Han Marta , Mizrahi Leila , Wiemer Stefan
Published: February 2023

The go-to models for developing time-dependent earthquake forecasts are Epidemic-Type Aftershock Sequence (ETAS) models. They model earthquake occurrence as a spatio-temporal self-exciting point process, using basic empirical laws such as the Omori-Utsu law for the temporal evolution of aftershock rate, the Gutenberg-Richter law to describe the size distribution of earthquakes, the exponential productivity law and so on. The main focus and core strength of ETAS lie in modelling aftershock occurrence. An important aspect which holds great potential for improvement is the modelling of background seismicity.In this study, we focus on the data sets and expert solicitations acquired for building the European Seismic Hazard Model (ESHM) 2020. Since these data sets cover a wide range of space and time, the properties of the earthquake catalogs (completeness magnitude, magnitude resolution, time and space resolution, b-value) vary by region and time period. We address these issues using the model accounting for the time-varying completeness magnitude (Mizrahi et al., 2021) and other adjustments, then develop an ETAS model that allows the background seismicity rate to vary with space and be covariate-dependent. The expectation-maximisation-based algorithm allows for these rates to be given as an input, in our case based on fault locations, estimated long-term seismicity rates and area sources, or estimated during inversion for expert-defined zonations. We test the models retrospectively for self-consistency and pseudo-prospectively to identify the ones that lead to the best operational forecasting model for Europe.
On the improved ensemble of multi-source precipitation through joint automated machine learning-based classification and regression
Authors: Chen Hao , Wang Tiejun , Montzka Carsten , Gao Huiran , Guo Ning , Chen Xi , Vereecken Harry
Published: February 2023

Accurate precipitation representation at local and global scales will greatly improve our understanding of climate system changes. However, no precipitation estimate consistently has the lowest errors (systematic biases, random error, and rain/no-rain classification error) under varying environmental gradients, resulting in considerable uncertainty when investigating mechanisms and making predictions. Multiple Source Precipitation Ensemble (MSEP) is regarded as an indispensable approach to this challenge. Based on an automatic machine learning workflow, we propose an MSPE framework that uses machine learning classification and regression jointly. Six distinct precipitation products (e.g., satellite- and reanalysis-based estimates) and their ensembles based on different framework strategies were examined comprehensively at 818 gauges across China and 500 randomly selected sites (representing ungauged regions). The unique features of MSPE were investigated, including the necessity of assigning spatiotemporal dynamic weights and the usage of machine learning classification and regression jointly. Results demonstrated that MSPE could effectively reduce both random and classification errors associated with precipitation occurrences. In addition, the capacity to generalize and the interpretability of the ML models developed within the framework were compared and discussed in depth. We also summarized the current framework's limitations and potential expansions. The framework presented in this research is expected to be a robust and flexible framework for the global application of ensembles of precipitation estimates from numerous scales, data sources, and time periods.
New tools on Terra Antiqua 2.0 applied to reconstructing the paleogeography of the India-Asia collision
Authors: Dupont-Nivet Guillaume , Aminov Jovid , Ruiz Diego , van der Linden Thomas , Gailleton Boris , Roperch Pierrick , Poblete Fernando , Meijer Niels , Kaya Mustafa , Licht Alexis , Gébelin Aude , Fang Xiaomin , Yuan Xiaoping , van Hinsbergen Douwe
Published: February 2023

Terra Antiqua is a plugin for QGIS to make paleogeographic reconstructions with a user-friendly graphical interface. The goal of Terra Antiqua is to make paleogeographic reconstructions accessible and attractive to a much wider range of users, typically Earth and Life scientists and students, without extensive expertise in programming and GIS analyses. Yet Terra Antiqua can also be attractive for GIS developers as our reconstruction algorithms are accessible through application programming interfaces (APIs), open source Github repository and written in python with open standards (e.g. OpenLayers, OGC, GDAL). Starting from physiographic features and datasets rotated back to the desired reconstructed age (typically using Gplates), the previous release of Terra Antiqua offered a set of primary tools to run the main steps of a global reconstruction (1. Combine topo-/bathymetry, 2. Set Paleoshorelines, 3. Modify topo/bathymetry and 4. Create topo/bathymetry) and secondary tools to improve and enhance the result. From this first simple release we are incrementally adding tools and features inspired by various methods developed by experienced paleogeographers. The new release, Terra Antiqua 2.0, has integrated a new set of options on the existing tools, including the ability to create physically realistic geomorphic features. These new options will be presented within the controversial example of the reconstruction of the India-Collision and the development of the Tibetan-Himalayan orogen. Several reconstructions stemming from competing topographic and geodynamic models are thus compared and assessed based on compiled datasets including updated paleoaltimetry.
Geophysical-petrological model for bidirectional mantle delamination of the Adria microplate beneath the Apennines and Dinarides orogenic systems
Authors: Jimenez-Munt Ivone , Zhang Wentao , Torné Montserrat , Vergés Jaume , Bravo-Gutierrez Estefanía , Negredo Ana M , Carminati Eugenio , Garcia-Castellanos Daniel
Published: February 2023

In this study we present a geophysical-geochemical integrated model of the thermochemical structure of the lithosphere and uppermost mantle of the Adria and Tisza microplates along two transects running from the Northern Apennines to the Pannonian Basin, and from the Southern Apennines to the Balkanides, respectively. The objectives are to image crustal thickness variations and characterize the different mantle domains. In addition, we evaluate the topographic response of opposed subductions and discuss their implications in the evolution of the region. Results show a more complex structure and slightly higher average crustal density of Adria compared to Tisza microplate. Below the Tyrrhenian Sea and Western Apennines, Moho is much shallower (< 25 km) than along the Eastern Apennines, where it can reach depths of 50-55 km. The LAB depth shows significant lateral variations, from the shallow LAB of the Tyrrhenian Sea and Western Apennines (< 80 km) to the thick LAB underneath the eastern Apennines and Adriatic Sea (150 and 125 km, respectively). Our results are consistent with the presence of two mantle wedges, resulting from the rollback of the Ligurian-Tethys and Vardar-NeoTethys oceanic slabs followed by continental mantle delamination of the eastern and western distal margins of Adria. These two opposed slabs beneath the Apennines and Dinarides are modelled as two thermal sublithospheric anomalies of -200°C. A Tecton garnet lherzolite (Tc_2 of Griffin et al., 2009) for the whole lithospheric mantle allows fitting geoid height and long-wavelength Bouguer anomalies. Most of the elevation along the profile is under thermal isostasy and departures can be explained by regional isostasy with an elastic thickness between 10 and 20 km.This research has been funded by the GeoCAM Project (PGC2018-095154-B-I00) with the contribution of the China Scholarship Council.
Engaging for geosite awareness based on GIS information
Authors: Veiga-Pires Cristina , Oliveira Sónia , Pereira Luís , Moura Delminda
Published: February 2023

In the last decade, GIS programs allowed to focus on the dissemination of international, national, and municipal data making them available for consultation or for download and future processing by the population. Several geoportals can be used to share the information, as Internet-based geospatial resources, allowing users to discover, view and access geospatial information and services provided by a wide range of organisations. From this data there are unlimited options for analysis by users, including students and teachers, such as making maps, 3D models and other applications.The Algarvensis aUGGp is relying on this technology for various purposes ranging from scientific site assessment and categorization, to educational and touristic engagement.Here, we present examples of practical applications based on GIS information, such as storymaps, digital terrain models in 3D and touristic maps.Storymaps are based on web applications that allow to tell a story in a dynamic way combining geographical maps with text and other multimedia contents. These applications are increasingly used in scientific dissemination, as well as educational tool within a wide range of themes. They have thus also great potential to enable the awareness about the geoparks and the geosites values to all the public in an interactive and appealing way as well as to support stakeholders and policy makers’ action and management decisions for conservation. Digital educational resource can also be used to explore the geosite during the pedestrian trails, but also as a virtual field trip in a classroom context, for instance. This study had the support of national funds through Fundação para a Ciência e Tecnologia (FCT), under the project LA/P/0069/2020 granted to the Associate Laboratory ARNET and UID/00350/2020 CIMA, as well as from the Municipalities of Loulé, Silves and Albufeira.
Potential impact of tropopause sharpness on jet latitude
Authors: Birner Thomas , Boljka Lina
Published: February 2023

The wintertime extratropical general circulation may be viewed as being primarily governed by interactions between Rossby waves and the background flow. These Rossby waves propagate vertically and meridionally away from their sources and amplify within the core of the tropopause-level jet, which acts as a waveguide. The strength of this waveguide is in part controlled by tropopause sharpness, which itself is a function of the strength of tropopause inversion layer (TIL), a layer of enhanced static stability just above the tropopause. Here, we report a strong relation between interannual-to-multidecadal variations in the strength of the midlatitude TIL and jet latitude in a reanalysis and climate models. Similar relationships hold for the variability across climate models. Experiments with a mechanistic model show that a sharper tropopause promotes an intensified general circulation and an equatorward shifted jet.Reference: https://doi.org/10.1038/s41612-022-00319-
Variability of the photosynthetic and fluorescence response of high mountain plants to climate change.
Authors: Aljazairi Salvador , Sebastià M.-Teresa , Agea Daniel , Sánchez-Cañete Enrique P. , Kowalski Andrew , Zamora Regino , Serrano-Ortiz Penelope
Published: February 2023

Alpine ecosystems have a high ecological value, high biodiversity, and provide important ecosystem services. However, alpine communities are highly vulnerable to climate changes. Changes in biodiversity and its distribution will affect the goods and services that these ecosystems provide. Also, it can affect climate regulation by altering the exchanges of greenhouse gases (GHG) and the cycles of carbon (C) and nitrogen (N), in feedback processes. Due to their ecological importance and vulnerability, alpine meadows deserve special attention. In this regard, the main objective of the IBERALP project is the analysis of the interactions between components of biodiversity, mainly plant and soil microbial diversity, and their relationship with GHG fluxes; and how these interactions are affected by climate change. IBERALP is focused on the alpine communities of five Iberian mountain National Parks: Picos de Europa, Ordesa and Monte Perdido, Aigüestortes i Estany de Sant Maurici, Sierra Nevada, and Sierra de Guadarrama. In each National Park, we selected two different altitudes and two different alpine community types based on soil conditions (mesic and xeric). Here we study leaf physiological and fluorescence parameters assimilation, respiration, the quantum yield of photosystem II (PhiPSII), maximum quantum efficiency (Fv`/Fm`) and photochemical quenching (qP) in two representative plant species (a legume (Trifolium repens) and a grass (Nardus strita)) present in each National Park. In addition, we recorded altitude and humidity soil condition using a portable photosyntheic system (Li-cor 6800; Li-Cor Inc.) with an integrated fluorescence chamber head. Multiple factors affect the ability of plants to assimilate CO2 and photoprotect themselves from solar radiation excess, so there was no common pattern for all Parks. However, in general, plants at higher altitudes showed a greater photosynthetic and photoprotection capacity against high irradiances compare to those at lower altitudes. Similar behaviour was found in mesic versus xeric communities. Exceptions were found, such as, for example, in Picos de Europa National Park, where the intense fog and grazing (with continuous contribution of N to the soil) modified these patterns of photosynthesis and photoprotection. This work was supported by the OAPN through the project PN2021-2820s (IBERALP).
A conceptual model for a fractured volcanic aquifer to investigate the role of climate variability and water withdrawal on recent changes in water-table and discharge
Authors: Bonaccorso Brunella , Silipigni Marco , Di Salvo Cristina , Borzì Iolanda , Preziosi Elisabetta
Published: February 2023

The Alcantara River Basin is located in North-Eastern Sicily (Italy), encompassing the north side of Etna Mountain, the tallest active volcano in Europe. On the right-hand side of the river, the mountain area is characterized by volcanic rocks with a very high infiltration. Here, precipitation and snow melting supply a big aquifer whose groundwater springs at the mid/downstream of the river, mixing with surface water and contributing to feeding the river flow also during the dry season. In the upstream a maximum of 520 l/s are extracted for municipal use through wells and an infiltration gallery supplying the Alcantara Aqueduct. In summer 2020 and 2021, the river suffered a prolonged dry phenomenon in the middle-valley stretch with a serious loss of fish fauna, due to significant spring depletion along the stream most likely determined by a meteorological drought. Since this anomaly is of great concern, the need arises to better understand whether the interaction between the water abstraction to supply the Alcantara aqueduct and the natural recharge of the aquifer is compatible with maintaining the balance of aquatic ecosystems in the middle-downstream valley of the Alcantara River also during dry years; or if the observed changes may also be partly due to other mechanisms, such as illegal or unaccounted water abstractions or hydrogeological modification due to the volcanic activity. To this end, in this study, an attempt was made to analyze changes in the groundwater level and in the interconnection between surface and groundwater by using the widely accepted MODFLOW 6, a finite-difference numerical model that in principle can provide constraints to reduce uncertainty and address field activity in data scarce case studies. The model was calibrated in steady state by comparing simulated and observed water heads as well as the groundwater budget. Then the simulation was run in transient mode for the period 2014–2021. The model outcome showed a depletion rate compatible with the one observed during the recent dry summers, thus suggesting that more sustainable and comprehensive strategies, also including groundwater extraction regulations, should be implemented to preserve this natural resource for in-stream water use and ecosystem services.
Sequestering soil organic carbon by planting hedgerows in agricultural landscapes
Authors: Biffi Sofia , Chapman Pippa , Ziv Guy
Published: February 2023

Recent policy initiatives have placed a strong focus on the use of agricultural soils for atmospheric CO2 removal by adopting practices for sequestering and storing SOC. In the UK, changes in agricultural land use, such as the integration of woody species in the form of hedgerows--lines of regularly trimmed shrubs commonly used to delimit agricultural fields--, have been recommended for climate change mitigation. The Climate Change Committee has proposed a 40% increase in hedgerow length across the country as a key contribution to net-zero targets. In England, this would equate to 193,000 km of newly planted hedgerows. However, the contribution of hedgerow planting to reaching net-zero goals remains unclear due to a lack of data on the rate at which CO2 is taken up and stored in the soil beneath them. In our study, seventy-eight hedgerows across six different pedo-climatic conditions in England were classified into four age categories. Soil organic carbon (SOC) stocks were quantified at 10 cm intervals for the top 50 cm of soil beneath hedgerows and in adjacent grassland fields. Moreover, we examined the distribution of SOC among particle-size fractions to investigate how hedgerow planting may influence SOC dynamics by affecting the quality and long-term stability of organic matter in soils, particularly to illustrate why hedgerow-associated SOC stocks are rapidly lost after hedgerow removal. SOC stocks beneath hedgerows were higher than adjacent fields for all age categories and hedgerows stored an average additional 40% SOC stock in the top 50 cm of soil compared to adjacent fields and 30% in the top 30 cm of soil. The additional SOC stock beneath hedgerows was 40.9 Mg C ha-1 at 0-50 cm depth, or 6.1 Mg C km-1. We used a 37-year-old SOC sequestration rate to show that if England were to reach its goal of 40% increase in hedgerow length, 6.3 Tg of CO2 will be sequestered and stored in the soil over 40 years (9.9 Tg with aboveground biomass). However, it will take ~200 years to reach this target with current rates of planting in national public agri-environment schemes. These results contribute measurable outcomes towards the estimate of targets for net-zero 2050 and the extent of ecosystem services provision by hedgerow planting in agricultural landscapes. 
CARS - Catalog of Relative Seismic Locations of 1981-2018 Italian Seismicity
Authors: Michele Maddalena , Di Stefano Raffaele , Chiaraluce Lauro , Latorre Diana , Castello Barbara
Published: February 2023

The Istituto Nazionale di Geofisica e Vulcanologia (INGV) monitors the Italian peninsula seismicity by using the data recorded by the Italian National Seismic Network (RSN) together with the ones gathered by other permanent regional networks (PRN). Earthquakes are real-time located by the INGV surveillance system and manually revised by the Italian Seismic Bulletin (BSI) group analysts.Starting from a catalog composed by homogeneous absolute locations (CLASS; Latorre et al., 2023), obtained by using a 3D regional-scale velocity model, we generated a catalog of relative seismic locations (CARS) of about 310,000 events occurred in Italy during 1981-2018.We inverted absolute P- and S- waves arrival times derived from data collected by RSN plus PRN for the period 1981-2008 and only by RSN for 2009-2018 to apply the double-difference relocation algorithm (Waldhauser and Ellsworth, 2000).For the second period, we combined the absolute travel times with relative ones obtained by waveforms cross-correlations analysis performed on pairs of similar events. The time domain cross‐correlation method proposed by Schaff et al., 2004 and Schaff & Waldhauser, 2005 was applied to seismograms of all pairs of events separated by 10 km or less and recorded at common stations. Seismograms were filtered in the 1–15 Hz frequency range using a four pole, zero phase band‐pass Butterworth filter. The correlation measurements were performed on 1.0 s long window for P- and S-waves. We collected a total of ~17 million P- and ~23 million S-wave delay times, retaining all measurements with correlation coefficients greater than 0.7.1D velocity models characterising 18 different (geologically, seismically and tectonically homogeneous) Italian macroareas (after Pastori et al. B2-2019-2021, Wp1-task4) were used in the location procedure.To cope with the memory limits (15,000 events with less than 200 readings) of the HypoDD code so to use it in a steady operational mode, we first subdivided the study region in the 18 macroareas related to the velocity models, then we additional discretize each in 100x100km2 cells, overlapped by the 80% in longitude and latitude. We repeatedly produced hypocentral locations of the same events that we merged by computing a final weighted mean location.We present the double-difference catalog of Italian seismicity, allowing to depict alignments clearer with respect to the starting catalog (CLASS), to be related to seismogenic faults and/or to regional structures along the whole Italian peninsula.
Towards integrated numerical models of lithospheric-scale magmatic systems
Authors: Kaus Boris , Kiss Daniel , de Montserrat Albert , Riel Nicolas , Berlie Nicolas , Spang Arne
Published: February 2023

Understanding the dynamics of magmatic systems requires numerical models that take the physics of the involved processes into account and allows interpreting geophysical and geological data in a consistent manner.  In climate science, a similar venture started over 5 decades ago with the generation of the first quantitative climate models, which has been indispensable in our understanding of the ongoing climate change. A similar effort for magmatic systems does not yet exist, even when many processes can already be described quantitatively.Here, we will discuss recent progress towards creating a modelling framework to simulate magmatic systems, developed as part of the ERC MAGMA project. We initiated several open-source packages in the Julia programming language that significantly simplifies creating new codes that simulate different processes and run on both workstations and high-performance GPU systems.This makes it straightforward to create a 3D model of a particular system taking available data into account (using GeophysicalModelGenerator.jl), use that as input for 3D models that link uplift/gravity data with dynamic models (using LaMEM), or simulate the thermal evolution and zircon age distribution following the intrusion of dikes & sills (using MagmaThermoKinematics.jl). One can easily switch the employed rheologies/parameterisations in the FEM or finite difference simulations, create synthetic seismic velocity models from the output (using GeoParams.jl) or account for the evolving chemistry of the magmatic system (using MAGEMin_C.jl).In this presentation, we will discuss implementation details and show that the use of GeoParams, for example, slows down pseudo-transient codes (as expected) but not substantially, whereas it results in much shorter codes.
Carbon dioxide, methane and heat emissions of the Monterotondo Marittimo and Sasso Pisano geothermal areas (Tuscany, Italy)
Authors: Ariano Alessandra , Frondini Francesco , Cardellini Carlo , Chiodini Giovanni , Petrelli Maurizio , Vetuschi Zuccolini Marino , Virgili Giorgio
Published: February 2023

In the central part of Tuscany region (Italy), is located the Larderello – Travale geothermal system which is a large-scale steam dominated system with reservoir temperatures that can exceed 350°C (Bellani et al. 2004). The characteristic high heat flow in this particular area is due to the presence of a thermal anomaly caused by the intrusion of a big Pliocene batholith into the upper crust (Musumeci et al. 2002). This work is aimed at investigating the relationships between carbon emissions and heat, particularly to analyse the distribution of CO2, CH4 and soil temperatures in the Monterotondo Marittimo and Sasso Pisano areas. Three hundred measurements of gas fluxes from the soil have been performed using the accumulation chamber method. CO2 fluxes range from 0.1 gm-2d-1 to about 20,000 gm-2d-1, while CH4 fluxes, available for a lower number of points, vary between 0 and 637 gm-2d-1. Soil temperatures were also measured at each location and ranges from 8.0 °C to 100 °C, with an average of 39.8 °C.CO2 fluxes show a polymodal statistical distribution with (i) a background population characterised by an average CO2 flux in the order of 16.0 g m-2 d-1 and (ii) anomalous populations with an average CO2 flux of 400 g m-2 d-1 and 1600 g m-2 d-1   for Sasso Pisano and Monterotondo Marittimo respectively. Not null CH4 fluxes were measured only at points with a CO2 flux in the range of the anomalous CO2 flux population. The statistical distribution of the CH4 resulted more complex with two populations characterized by an average value of 0.8 g m-2d-1 and 174 g m-2d-1 respectively, probably reflecting differences in the gas transport mechanism in the soil and/or soil permeability, which is largely variable in the areas with anomalous flux.The areas characterized by anomalous soil gas fluxes, show also an evident soil temperature anomaly (reaching values close to 100 °C), suggesting that soil degassing is accompanied by a significant process of steam condensation. In the anomalous areas, the CO₂/CH₄ ratios by weight vary between 1.6 x 10-4 to 1.0 x 10-1 and fall in the range of variation observed for the geothermal fluids of the Larderello-Travale region (Truesdell & Nehring, 1978; Chiodini et al., 1991; Chiodini & Marini, 1998).Assuming that the soil is heated by steam condensation, a thermal energy release associated to the degassing process of about 200 MW is estimated for Monterotondo Marittimo, an energy release >15 MW is estimated for Sasso Pisano, where the measurements are still in progress.
Atmospheric excitation of length of day inferred from 21st century climate model projections
Authors: Böhm Sigrid , Salstein David
Published: February 2023

The Coupled Model Intercomparison Project Phase 6 (CMIP6) provides, amongst others, the Earth climate response to several different scenarios that simulate possible future anthropogenic drivers of climate change. The scenarios are characterized by different forcings, which are defined from a combination of plausible future societal developments, the Shared Socioeconomic Pathways (SSPs), and the Representative Concentration Pathways (RCPs), identified by the approximate radiative forcing level anticipated for 2100.In a previous work, we investigated length of day variations induced by multi-model projections of zonal wind fields, stemming from historical simulations and from the four scenarios SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5. In order to cover the same set of five scenarios that are treated in the sixth assessment report of the Intergovernmental Panel on Climate Change, we add another low emission scenario, SSP1-1.9, in this follow-up study. Furthermore, we do not only assess the wind term but complete the analysis with the calculation of the respective atmospheric surface pressure terms. We are especially interested in the long-term variations and trends of length of day predicted for the period from 2015-2100 and the connection with variations and trends of the global surface temperature patterns. Regarding the excitation by zonal winds, preliminary assessments show that higher emission scenarios, which are associated with more intense global warming, would lead to a moderate increase in atmospheric angular momentum and thus to a proportional decrease of the Earth rotation rate.
Insights into the linear dynamics between sea ice and atmosphere through strong-coupled data assimilation
Authors: Xie Jiping , Bertino Laurent
Published: February 2023

Sea ice exists between the atmosphere and the ocean and plays a fundamental role in the global energy budget. In recent years, the satellite-based sea ice thickness (SIT) combined from Cryosat2 and SMOS has been assimilated into different ice-ocean coupled model systems and shows the Arctic SIT can be constrained well. However, few studies investigate how large extent to which the dynamic link between sea ice and the atmosphere has been corrected. In this study, in a strongly coupled ocean and sea ice data assimilation system-TOPAZ, the two parallel assimilation runs were done with and without assimilation of SIT during 2014-2017. Except for assimilating SIT, these two runs all assimilate other types of ocean and sea ice observations. Firstly, comparing the autocorrelations of SIC and SIT, respectively, the SIT variability shows a much longer timescale (100 days). Furtherly, we investigate the differences incurred from the additional assimilation of the SIT observations. The analysis highlights the dynamics between the SIT and the key variables from the atmospheric forcing through the singular value decomposition (SVD), which improves understanding of the coupling responses between sea ice and the atmosphere.

Keywords: Strong-coupled data assimilation; Linear dynamics; Sea ice thickness; TOPAZ