bluuebunny/crossref_metadata_2025 huggingface dataset:
Climate change impact on surface ozone based on CMIP6 Earth System Models
Authors: Zanis Prodromos , Akritidis Dimitris , Turnock Steven , Naik Vaishali , Szopa Sophie , Georgoulias Aristeidis Κ. , Bauer Susanne E. , Deushi Makoto , Horowitz Larry W. , Keeble James , Le Sager Philippe , O'Connor Fiona M. , Oshima Naga , Tsigaridis Konstantinos , van Noije Twan
Published: March 2022

It is presented an analysis of the effect of climate change on surface ozone (O3) discussing the related penalties and benefits around the globe from the global modeling perspective based on simulations with five CMIP6 (Coupled Model Intercomparison Project Phase 6) Earth System Models. All models conducted simulation experiments considering future climate (ssp370SST) and present-day climate (ssp370pdSST) under the same future emissions scenario (SSP3-7.0). Over regions remote from pollution sources, there is a robust decline in mean surface ozone concentration varying spatially from -0.2 to -2 ppbv oC-1, with strongest decline over tropical oceanic regions, which is mainly linked to the dominating role of enhanced ozone chemical loss with higher water vapour abudances under a warmer climate. However, ozone increases over regions close to anthropogenic pollution sources or close to enhanced natural Biogenic Volatile Organic Compounds (BVOC) emission sources with a rate ranging regionally from 0.2 to 2 ppbv oC-1, implying a regional surface ozone penalty due to global warming. The individual models show this robustly for south-eastern China and India as well as for regions of Africa but there are inter-model differences in areas within Europe and the United States (US) as well as in South America. The future climate change enhances the efficiency of precursor emissions to generate surface ozone in polluted regions and thus the magnitude of this effect depends on the regional emission changes considered in this study within the SSP3_7.0 scenario. The comparison of the climate change impact effect on surface ozone versus the combined effect of climate and emission changes indicates the dominant role of precursor emission changes in projecting surface ozone concentrations under future climate change scenarios.

 

The authors from Aristotle University of Thessaloniki acknowledge funding from the Action titled "National Νetwork on Climate Change and its Impacts - CLIMPACT" which is implemented under the sub-project 3 of the project "Infrastructure of national research networks in the fields of Precision Medicine, Quantum Technology and Climate Change", funded by the Public Investment Program of Greece, General Secretary of Research and Technology/Ministry of Development and Investments.
Snow Cover Analysis of Turkey comparing to Historical Climate Scenarios of CMIP5 and CMIP6 protocols
Authors: Aksu Aleyna Nur , Hazar Ipeknur , Dursun Bahattin Can , Yogun Buket , Tan Elcin
Published: March 2022

Profound changes have been observed in the precipitation pattern of Turkey due to climate change during the last decade. This variation in precipitation pattern affects the amount of snow cover and the temporal and spatial distribution of snow. In addition, significant variability was observed in the initial time of snowmelt that water resources, especially groundwater, might be adversely affected. On the other hand, this adverse effect in snow cover is also crucial for Turkey's winter sports tourism. For this reason, the study aims to analyze the historical simulation results of climate models (MIROC5 and MIROC6; CanESM2 and CanESM5; and GISS-E2-H and GISS-E2-1-H) based on CMIP5 and CMIP6 protocols depending on snow cover variables and compare the consistency of these models with observations. Probability distribution functions of surface snow area fraction and snowfall flux variables over ten-year periods were analyzed. In addition, the frost days index (ECAFD), Ice days index (ECAID), and very cold days (ECATX10P) index were also analyzed. As a preliminary result, it was found that the snow cover values of the CMIP6 protocol climate models were more consistent with the observations.
Adjoint modeling of load-tide sensitivity 
Authors: Dmitrovskii Andrei A. , Martens Hilary , Khan Amir , van Driel Martin , Boehm Christian
Published: March 2022

Deformations of the solid Earth as a response to ocean tidal loading (OTL) are sensitive to the material properties of Earth’s interior across a broad range of spatial and temporal scales. Studying tidal response can provide constraints on the interior structure, which are complementary to seismic tomography and particularly important to explore the interior response to low frequency loads. Although seismic tomography is widely used to constrain the Earth’s interior, it is prone to be only slightly sensitive to the density distribution in the interior with an increase of the sensitivity towards the long period signal. Whereas previous research (e.g. Ito & Simons, 2011, Martens et al., 2016) has shown that the tidal surface displacements may be sensitive to elastic properties of the interior to the same extent as to the mass distribution in the lithosphere and the mantle. The latter are of massive interest to all fields of geophysics and especially geodynamics.

We present a numerical approach to simulate the elastic and gravitational responses of the solid Earth that relies on the spectral-element method. Modeling the governing equations in a 3-D Earth using a coupled system of the elastostatic and Poisson’s equations enables us to include effects like topography or lateral variations in Earth structure. The adjoint method is a powerful technique to simultaneously compute sensitivity with respect to all material parameters, e.g., density and elastic moduli, by solving an auxiliary linear system. We introduce a recipe for computing adjoint-based sensitivities of the complex-valued amplitude of surface displacement by two simulations for the real and imaginary part of the surface load. Those two simulations are independent under assumption of negligible attenuation.
Seasonal forecasts of cereal crop yields in Iberia
Authors: Bento Virgílio , Russo Ana , Dutra Emanuel , Ribeiro Andreia , Gouveia Célia , Trigo Ricardo
Published: March 2022

Climate change is likely to impact the balance of worldwide food exchange networks and food security. Hence, the use of seasonal forecasts of precipitation and temperature may be regarded as essential for stakeholders to perform timely choices concerning the strategies required to maximize the expected cereal yield outcomes in the harvest period. The availability and ease-of-use of the seasonal forecasts from the European Centre for Medium-Range Weather Forecasts (ECMWF) system 5 (SEAS5) may be an important asset to help implement these strategies by decision makers. Nevertheless, uncertainties and reduced skill may hinder the use of such forecasts for numerous applications. Thus, this work intends to analyse the added value of using dynamical forecasts when compared to using persistent anomalies of climate conditions, with the aim of predicting the production of wheat and barley yields in Iberia. First, empirical models involving annual wheat and barley yields in Spain and monthly values of precipitation and temperature are developed with ECMWF ERA5 reanalysis. Then, dynamical and persistence forecasts are issued at different lead times, and the skill of the forecasted yield is verified through different metrics. Results presented here show that wheat and barley yield anomaly forecasts (dynamical and persistent) start to gain skill later in the season (e.g., April) and show that the added value of using the SEAS5 forecast as an alternative to persistence varies between 6 and 16 %, with better results in the southern Spain regions.

The authors would like to acknowledge the financial support FCT through project UIDB/50019/2020 – Instituto Dom Luiz.
Large wood (LW) and sediment (dis-)connectivity in river systems: Introducing the newly developed LW (dis-)connectivity and sediment storage potential indices and their application in river management contexts. 
Authors: Pöppl Ronald , Fergg Hannah , Perez John
Published: March 2022

In-stream large wood (LW) can have significant effects on channel hydraulics and thus water and sediment connectivity. The relationship between LW structures and their hydraulic function is generally quantified through drag force. Drag analyses, however, are often not straightforward, especially in complex debris jam settings where LW accumulations often consist of wood pieces of variable sizes. Here, we introduce simple LW (dis-)connectivity and sediment storage potential indices, especially developed for river management assessments. The LW (dis-)connectivity index (IDLW) is calculated based on visually estimated, field-derived parameters such as the degree of channel blockage. The LW sediment storage potential index (ISLW) is based on a classification scheme differentiating between different types of LW accumulation. Both indices were calculated and tested in two medium-sized mixed-load streams in Austria, further assessing fine sediment retention volumes behind LW structures. In both systems a variety of different types of LW accumulation with different degrees of blockage and storage potential have been detected. The larger system (river length = 5.7 km) had IDLW and ISLW values of 0,75 and 0,027, the smaller system (river length = 1.3 km) of 1,76 and 0,057. In the larger system in total 88.7 m³ fine sediment have been found to be retained by LW, while 4.7 m³ have been accumulated behind LW structures in the smaller river system. The application of the newly developed indices has shown to be a straightforward and valuable method to assess the effects of LW on water and sediment (dis-)connectivity, especially in a river management context.
Evaluating the sustainability of low enthalpy geothermal applications in a subsurface heat island
Authors: Previati Alberto , Silvestri Valerio , Frattini Paolo , Crosta Giovanni B.
Published: March 2022

Low enthalpy geothermal applications such as ground coupled heat pumps (GCHP) and groundwater heat pumps (GWHP) are an attractive low-carbon solution for heating and cooling of buildings. Their efficiency depends on the subsurface thermal properties (e.g. thermal conductivity, heat capacity) and the hydrogeological/thermal regimes (e.g. groundwater flow, depth of the water table, temperature profile). The geothermal potential is an indicator used to quantify and compare the ability to exchange heat with the subsurface/groundwater according to specific technologies. Even though it has no unique definition, it is often obtained as a combination of the subsurface hydrogeological/thermal properties and the thermal regime and, by means of GIS techniques it can be spatialized to obtain geothermal potential maps.

The subsurface thermal properties vary in space according to the geological setting, while the hydrogeological and thermal regimes can vary both in space and time according to the fluid and heat budgets of the aquifers. However, despite few studies consider the variability of the geothermal potential in time due to possible variations of the hydrogeological and thermal regimes, it is essential to evaluate the efficiency of geothermal systems in a changing environment such as subsurface urban heat islands. The hydrogeological/thermal regimes are not stationary, especially beneath big cities where land and subsurface uses control the elevation of the water table and the shallow subsurface thermal regime. Moreover, the heating and cooling demand of buildings may vary due to climate change effects such as global warming and atmosphere urban heat island.

The potential to exchange heat with the subsurface in the Milan metropolitan area was estimated from hydrogeological and thermal regimes simulated by a fluid-flow/heat-transport city-scale numerical model, calibrated on the current state. Several scenarios were generated changing the boundary conditions according to projected changes of (I) the air temperature (based on RCP 2.6, 4.5 and 8.5 scenarios), (II) the groundwater head, (III) the land use/city size and (IV) the geothermal uses (based on the increment of installations and changes of the thermal demand), to estimate the changes and the seasonal variability of the subsurface temperature at different depths in different zones of the city. Finally, the future variations of the thermal potential were estimated for heating and cooling seasons combining the scenarios-projected subsurface temperatures with the hydrogeological and thermal properties, also considering the variation of heating and cooling thermal loads.
Energy Dissipation Rate Estimates from Airborne Atmospheric Measurements with the Max Planck CloudKites
Authors: Schröder Marcel , Nordsiek Freja , Schlenczek Oliver , Ibañez Landeta Antonio , Güttler Johannes , Bodenschatz Eberhard , Bagheri Gholamhossein
Published: March 2022

The energy dissipation rate is one of the most important characteristics of a turbulent flow across the entire range of scales, and of particle-turbulence interaction. To investigate cloud microphysics and turbulence in clouds and in the atmospheric boundary layer, we infer coarse-grained time series of the energy dissipation rate from one-dimensional wind velocity time records by specially developed airborne platforms, the Max-Planck-CloudKite + (MPCK+) and the mini-Max-Planck-CloudKites (mini-MPCK). During the EUREC4A-ATOMIC field campaign in the Caribbean January - February 2020, both instruments are deployed aboard balloon-kite hybrids launched from RV Maria S. Merian and RV Meteor conducting in situ measurements of the wind velocity and meteorological as well as cloud microphysical properties with high spatial and temporal resolution. We present estimates of the energy dissipation rate from in situ velocity time records by the MPCKs during the EUREC4A-ATOMIC field campaign and preliminary assessment of turbulence features.
Impact of fracture length distribution on the injection-induced seismicity in fractured rocks
Authors: Afshari Moein Mohammad Javad , lei Qinghua
Published: March 2022

Induced seismicity is a major challenge for fluid injection operations performed by geo-energy industry to exploit the underground resources. Despite recent developments in the understanding of induced earthquakes, many high-pressure fluid injection operations can still trigger unexpectedly large-magnitude events. A physical understanding of geological parameters controlling the induced seismicity is of central importance for improving our ability to forecast and mitigate the risk of inducing large earthquakes. Current physics-based numerical models are typically based on some simplifications that disregard the multiphysical interactions among fractures and faults. Therefore, the physical linkage between geometrical attributes of the fracture system and the statistics of induced seismicity is poorly understood. The final objective of this research is to determine the impact of fracture network properties on the spatiotemporal evolution of injection-induced seismicity and the emergence of large earthquake events.  

Here, we numerically capture the occurrence of seismic and aseismic slips in fracture systems, represented as discrete fracture networks (DFNs), spanning over two orders of magnitude over the length scale (1-100 m). Then, a 2D finite element model is used to simulate the coupled hydraulic and mechanical processes during fluid injection and analyze the occurrence of earthquakes. We present some preliminary results of our numerical simulations based on synthetic fracture network realizations. We particularly focus on power-law exponent of fracture length distribution and analyze the potential controls on the magnitude frequency of induced seismic events. The results of the analysis could have significant implications injection-related activities such as enhanced geothermal systems.
SimSphere: a software toolkit to facilitate teaching and research in the study of Land Surface Interactions 
Authors: Petropoulos George P. , Silva-Fuzzo Daniela F. , Bao Yangson , Sandric Ionut , Triantakonstantis Dimitris , Detsikas Spyridon E. , Srivastava Prashant K. , Lamine Salim
Published: March 2022

Climate change is facilitating large scale changes within the atmosphere, biosphere, geosphere, and hydrosphere evidenced globally at a variety of geographical scales. Thus, understanding physical processes and the ways the different components of the Earth system interact has been identified today as a topic of key research investigation. Use of simulation process models has played a key role in extending our abilities to study Earth system processes and enhancing our understanding on how different components of it interplay. This is due to their computational efficiency, accuracy, and ability to provide results at fine temporal scales. Soil Vegetation Atmosphere Transfer (SVAT) models have emerged recently as the preferred scientific tool to assess various parameters characterising the Earth system. Those can also be often combined with Earth Observation (EO) data, blending the horizontal coverage and spectral resolution of EO data with the fine temporal continuity and vertical coverage of those models. Several studies have drawn attention to this as a promising direction towards improving our ability to estimate key state variables characterising land surface interactions. SimSphere is such a software toolkit written in Java for simulating the interactions of soil, vegetation, and atmosphere layers of the Earth’s land surface. It is being used either as a stand-alone application or synergistically with EO data. This model since its foundation has evolved significantly both architecturally and functionally and its use has been widely demonstrated so far in a wide spectrum of interdisciplinary science investigations. Furthermore, it is currently used as an educational resource for students in several Universities Institutes globally. Herein, we focus on SimSphere which is used as a case of a successful paradigm of a SVAT model used in teaching and research activities relevant to the study of land surface processes. We provide an overview of the model use so far in a variety of applications and teaching activities whereas we also present the latest advancements conducted from our group in enhancing the model functionality which aim at making its use more robust when used both as a standalone application and synergistically with EO data. The present work is not only an important contribution to the continuously expanding group of the model users community, but it is also very timely more generally as it feeds to efforts currently ongoing by different groups globally towards the development of relevant operational products.
KEYWORDS: land surface, physical processes, SVAT, SimSphere, remote sensing, triangle
Regional variability in Amazon methane emissions based on lower-troposphere observations
Authors: Basso Luana , Gatti Luciana , Marani Luciano , Miller John , Gloor Manuel , Melack John , Cassol Henrique , Tejada Graciela , Domingues Lucas , Arai Egidio , Sanchez Alber , Corrêa Sergio , Anderson Liana , Aragão Luiz , Correia Caio , Crispim Stephanie , Neves Raiane
Published: March 2022

After a period where atmospheric methane (CH4) levels were nearly steady, its levels have been rapidly raising since 2007, but the main reasons remains uncertain. Increases in wetlands emissions could be one possible reason, mainly at tropical regions like Amazonia, which host some of the largest wetlands/seasonally flooded areas on the globe. Based on 590 lower troposphere vertical profiles of CH4 and carbon monoxide (CO) observations over four sites at Amazon (at the northeast, southeast, northwest-central and southwest-central regions) we estimated that Amazon region contributes with 8% of global CH4 emissions, and wetlands are the mainly CH4 source to the atmosphere (Basso et al., 2021). Vertical profiles are sampled using light aircraft, high-precision greenhouse gas and CO analysis of flask air, fortnightly between 2010 and 2018. We observed an unexpected east-west gradient in CH4 emissions, with higher emissions in northeast Amazon region. The higher emissions are mainly from wetlands and are not explained by biomass burning and anthropogenic emissions (like enteric fermentation), but its causes remains unclear. In the other three sites located further downwind along the main air-stream the CH4 emissions represents approximately 24-36% of what is observed in the northeast region. Our wetlands emission estimates of each region were compared to analogous fluxes from the WetCharts wetland model ensemble (Bloom et al., 2017). The estimates were similar except for the northeast region, where WetCharts does show substantial emissions, but still just 40% of our estimates based on the lower troposphere observations (Basso et al., 2021).
A framework for modelling groundwater floods and its applications for forecasting and assessing the impact of climate change in groundwater systems: examples from Ireland
Authors: Campanyà i Llovet Joan , McCormack Ted , Naughton Owen
Published: March 2022

Climate change will have a major impact on Ireland’s water resources. It will pose significant risks to water management and exacerbate existing pressures in terms of water supply, quality, flooding and drought. Early detection of these pressures in hydrological regimes is key to informing adaptation strategies and minimizing adverse environmental and societal impacts. In response to this risk, a framework was developed to enable short-term forecasting of groundwater levels, and to quantify and analyse the impact that climate change will have on Irish groundwater systems.

A key element of the framework is the use of robust hydrological models to simulate groundwater levels. The framework was developed in Python, with a particular focus on groundwater flooding, and incorporates two modelling approaches: 1) mathematical transfer functions (combination of exponential decay, gamma distribution, and linear decay functions), and 2) a physically based lumped model (reservoir model). For both modelling approaches, precipitation data is converted to effective rainfall based on soil moisture deficit and evapotranspiration data, and the model parameters are calibrated using a Bayesian Markov Chain Monte Carlo algorithm.

The framework was tested and implemented with synthetically generated groundwater level time series, and with a selection of 12 groundwater dependent wetlands covering a wide range of hydrological behaviours. The tested approaches have proof successful to: 1) produce viable numerical models for those systems, with Nash-Sutcliffe Efficiency (NSE) and Kling-Gupta Efficiency (KGE) values between 0.85 and 0.98 for most of the sites calibration and validation datasets, and 2) inform on how the groundwater systems operate (i.e. multiple outflows, changes in catchment area). The models are now used for forecasting groundwater levels and assessing the potential impact of climate change in ecologically important wetlands.

The outputs of this project will improve the national ability to understand how groundwater resources respond to climatic stresses and improve the reliability of adaptation planning and predictions in the groundwater sector.
Four year-long observations from a key inflow region onto the southern Weddell Sea continental shelf
Authors: Steiger Nadine , Sallée Jean-Baptiste
Published: March 2022

The Filchner Trough on the continental shelf in the southern Weddell Sea is the gateway for warm water from off the continental shelf to flow towards the Filchner Ice Shelf. The warm water is steered southward along the eastern slope of the trough, potentially increasing basal melt rates of the ice shelf and leading to the formation of cold and dense Ice Shelf Water that overflows and contributes to the Antarctic Bottom Water. We present mooring time series from 2017 to 2021 in key inflow regions of modified Warm Deep Water onto the eastern continental shelf. Three moorings were placed across the eastern flank of the Filchner Trough close to the shelf break and captured the changes in the thickness of the northward-flowing Ice Shelf Water as well as the overlying southward warmer water. Another mooring was placed over the shallower eastern shelf and allowed a comparison between the two pathways of warm water onto the continental shelf. The four-year-long observations provide a better understanding of the processes that influence the seasonal and interannual variability in temperatures and circulation and possible changes in the flow of warm water towards the ice shelf.
The added value of forcing, surface parameter and land model to the high resolution soil moisture modeling in China
Authors: Ji Peng , Yuan Xing
Published: March 2022

Soil moisture is a vital land surface variable that influences the terrestrial hydrothermal cycles, modulates the land-atmosphere interactions and provides important predictability for weather and climate forecasting. Numerous efforts have been made to investigate the contribution of meteorological forcings, land surface parameters and land models to the uncertainties or precision of soil moisture modeling through both complex statistical approaches and simple comparative land surface modeling experiments. However, previous research mainly focus on one or two factors and the influence of a specific factor is usually quantified by comparing two different datasets. It still unclear that how much added value the current high resolution forcings, surface parameters and land models have to the soil moisture modeling and whether the results depend on the choice of model, datasets and even study regions.

To address the above issue, we first performed a high resolution (6km) soil moisture modeling over China during 2012~2017 by using the newly developed Conjunctive Surface-Subsurface Process version 2 (CSSPv2) land model forced by high-resolution meteorological forcing and high-resolution soil hydraulic property data. The high-resolution simulation has good performance in representing the observed magnitudes and variations of the rootzone (0~1 m) soil moisture based on >1,500 soil moisture stations, and improves the Kling-Gupta efficiency by 33~118% from the current high-resolution global land reanalysis (e.g., ERA5-Land and GLDASv2.1) and remote sensing based products (e.g., ESA CCI and GLEAMv3.1). In order to quantify the contributions from forcings, parameters and CSSPv2 model, we repeated the simulation by using coarse resolution datasets and different models including three meteorological forcing datasets, two soil hydraulic property datasets and three land models. By comparing 48 sets of experiments, the model and soil parameter are found to contribute more than 50% of the improvements at national scale which indicates necessity of developing high resolution land models and model parameters. On the regional scale, however, the meteorological forcing is shown to has the largest added value over the northwestern and southwestern China while land model is most important for the improvement over southern and eastern China. Further works will analyze the specific physical process in CSSPv2 model that improve the soil moisture simulation which will shed light on the future land model development.
Monitoring Solanum lycopersicum var. Elpida salinity stress using multispectral imaging
Authors: Papadimitriou Dimitris , Daliakopoulos Ioannis , Constantinopoulos Constantinos , Manios Thrassyvoulos , Kosmopoulos Dimitrios
Published: March 2022

Under salinity stress, plant physiology and yield characteristics deteriorate, showing, among others, symptoms similar to those of water stress. Tomato (Solanum lycopersicum) is moderately sensitive to salinity stress and suffers yield losses of over 15% at irrigation water electrical conductivity (ECw) of  3 dSm-1 (Malash et al., 2008) and over 25% at ECw of 3.5 dSm-1 (Daliakopoulos et al., 2019). As salinity can often buildup in soils and substrates, it can have a creeping effect not readily measurable in irrigation water ECw, therefore it is essential that plant physiology symptoms are spotted early to take corrective action. Here we investigate the potential of multispectral imaging, to detect early symptoms of salinity stress on S.lycopersicum plants (var. Elpida) due to NaCl accumulation in the nutrient solution of a soilless cultivation system. In this context, we established a control (0.5 mM) and five salinity treatments of 5.0, 10.0, 15.0, 20.0 mM NaCl, with three tomato plants (replications) per treatment, resulting in a total number of 18 S.lycopersicum plants. During the experiment, multispectral images (bands 460, 540, 630, 850, and 980 nm) were obtained at three stages of plant development (30, 60, and 90 days after transplant) using a MUSES9-MS sensor. For each multispectral image, four spectral indices (NDVI, OSAVI, LWSI and GOSAVI) were calculated. Although, the statistical analysis of the results reveal low sensitivity to the increasing salinity at early sampling stage (60 DAT), during the third sampling stage (120 DAT) all spectral indicators demonstrate significant sensitivity for treatments over 10.0 mM NaCl.

References

Daliakopoulos, I.N., Apostolakis, A., Wagner, K., Deligianni, A., Koutskoudis, D., Stamatakis, A., Tsanis, I.K., 2019. Effectiveness of Trichoderma harzianum in soil and yield conservation of tomato crops under saline irrigation. Catena 175. https://doi.org/10.1016/j.catena.2018.12.009

Malash, N.M., Ali, F.A., Fatahalla, M.A., A. khatab, E., Hatem, M.K., Tawfic, S., 2008. Response of tomato to irrigation with saline water applied by different irrigation methods and water management stratigies. Int. J. Plant Prod. 2, 101–116.

Acknowledgements
This research has been co-financed by the European Union and Greek national funds through the Operational Program Competitiveness, Entrepreneurship, and Innovation, under the call RESEARCH-CREATE-INNOVATE (project codes: T1EDK-04171)
Characterizing mantle deformation processes during the rift-to-drift transition at magma-poor margins
Authors: Montiel Nicholas , Massini Emmanuel , Lavier Luc , Müntener Othmar
Published: March 2022

A holistic understanding of rift initiation, evolution, and variation is made complicated by the difficulties of deep seismic imaging, limited modern examples of continental rifting, and few accessible outcrops of fossil rifted margins. In particular, The temporal structural and rheological evolution of the mantle lithosphere during riftingis poorly constrained. The mantle lithosphere rheology controls lithospheric strength at initiation, but how deformation is partitioned between the crust and mantle,  and how the paths for melt migration from the asthenosphere to the rift surface evolve during rifting is fundamental for our understanding of the rift-to-drift evolution .
Here, we use elastoplastic-viscoelastoplastic modeling in concert with published deep seismic profiles of Atlantic rifted margins and geological insights from the Lanzo peridotite outcrops in the Alps to propose a new mode of extensional tectonics in the subcontinental mantle. We run a series of dynamic models varying initial conditions and mechanisms of deformation localization in the mantle lithosphere consistent with mechanisms of ductile shear zone formation observed at slow spreading centers. Models and geophysical surveys show homologous, sigmoidal reflectors in the mantle, a reversal of fault vergence as seafloor spreading develops, exhumation of the mantle, and increasing magmatic accretion. Geological evidence, along with the coincidence of magmatic accretion and extensional structures in the mantle, suggests that faults in the mantle may serve as conduits for melt, resulting in bright reflectors on seismic profiles.
Temperature effects on carbon storage are controlled by soil stabilisation capacities
Authors: Hartley Iain , Hill Tim , Chadburn Sarah , Hugelius Gustaf
Published: March 2022

Physical and chemical stabilisation mechanisms are now known to play critical roles in controlling carbon (C) storage in mineral soils. This has led to suggestions that climate warming-induced C losses may be lower than previously predicted. However, evidence has also been produced that the decomposition of older, and more protected soil organic matter (SOM) is more sensitive to temperature than unprotected and more rapidly decomposing SOM pools. Thus, the extent to which temperature controls C storage in mineral soils remains controversial, and it is not known whether the C stores in soils with large capacities for stabilising C are more, or less, vulnerable to climate warming than the C stored in soils with more limited stabilisation capacities.

By analysing data on >9,000 soil profiles from the World Soil Information Database, we found that, overall, C storage declines strongly with mean annual temperature. However, we observed very large differences in the effect of temperature on C storage in soils with different capacities for stabilising SOM, as indicated by their textural properties. In coarse-textured soils (clay contents less than 20%) with more limited stabilisation capacities, C storage declined strongly with temperature, decreasing by a factor of 1.6 to 2.0 for every 10 oC increase in temperature. However, in fine-textured soils (clay contents greater than 35%) with greater stabilisation capacities, the effect of temperature on C storage was more than three times smaller. This pattern was observed independently in cool and warm regions, and after accounting for potentially confounding factors including plant productivity, precipitation, aridity, cation exchange capacity and pH. The difference in the effects of temperature on C storage in soils with contrasting stabilisation capacities could not, however, be represented by an established Earth system model (ESM). To reduce uncertainties in projections of the effect of climate change on soil C losses, we suggest that ESMs could be evaluated against their ability to simulate the differences in the effects of temperature on C storage in soils with contrasting textural properties.

In conclusion, our results suggest that there are stabilised pools of SOM in fine-textured soils that may be relatively insensitive to the impacts of climate change, but that less protected pools in coarser-textured soils may be substantially more vulnerable to global warming than currently predicted. Finally, given the mismatches between data and model outputs, ESMs may not be predicting accurately the potential magnitude of soil C losses in responses to climate warming or which stocks are most vulnerable.
Connecting subduction, extension, and shear localization across the Aegean Sea and Anatolia
Authors: Barbot Sylvain , Weiss Jonathan
Published: March 2022

The Eastern Mediterranean is the most seismically active region in Europe due to the complex interactions of the Arabian, African, and Eurasian tectonic plates. Deformation is achieved by faulting in the brittle crust, distributed flow in the viscoelastic lower-crust and mantle, and Hellenic subduction, but the long-term partitioning of these mechanisms is still unknown. We exploit an extensive suite of geodetic observations to build a kinematic model connecting strike-slip deformation, extension, subduction, and shear localization across Anatolia and the Aegean Sea by mapping the distribution of slip and strain accumulation on major active geologic structures. We find that tectonic escape is facilitated by a plate-boundary-like, trans-lithospheric shear zone extending from the Gulf of Evia to the Turkish-Iranian Plateau that underlies the surface trace of the North Anatolian Fault. Additional deformation in Anatolia is taken up by a series of smaller-scale conjugate shear zones that reach the upper mantle, the largest of which is located beneath the East Anatolian Fault. Rapid north-south extension in the western part of the system, driven primarily by Hellenic Trench retreat, is accommodated by rotation and broadening of the North Anatolian mantle shear zone from the Sea of Marmara across the north Aegean Sea, and by a system of distributed transform faults and rifts, including the rapidly extending Gulf of Corinth in central Greece and the active grabens of western Turkey. Africa-Eurasia convergence along the Hellenic Arc occurs at a median rate of 49.8 mm/yr in a largely trench-normal direction, except near eastern Crete where variably-oriented slip on the megathrust coincides with mixed-mode and strike-slip deformation in the overlying accretionary wedge near the Ptolemy-Pliny-Strabo trenches. Our kinematic model illustrates the competing roles the North Anatolian mantle shear zone, Hellenic Trench, overlying mantle wedge, and active crustal faults play in accommodating tectonic indentation, slab rollback, and associated Aegean extension. Viscoelastic flow in the lower crust and upper mantle dominate the surface velocity field across much of Anatolia and a clear transition to megathrust-related slab pull occurs in western Turkey, the Aegean Sea, and Greece. Crustal scale faults and the Hellenic wedge contribute only a minor amount to the large-scale, regional pattern of Eastern Mediterranean interseismic surface deformation.
Chaotic mixing in laminar flows through rocks
Authors: Puyguiraud Alexandre , Le Borgne Tanguy , Heyman Joris
Published: March 2022

Recent studies have shown that chaotic advection is spontaneously produced by laminar flows through granular media such as bead packs, strongly impacting solute mixing rates. This has strong implications for many reactive and biological processes in the subsurface. Chaotic dynamics could also be key in a wide range of environmental and industrial applications driven by mixing. Beside granular media, there is still no evidence that chaos broadly arises in the large variety of porous architectures that exist. In particular, it is unknown how the pore structure and topology can control chaotic dynamics.
In this study, we numerically investigate the mixing behavior of solute for a wide range of natural and engineered porous material that goes from carbonates and sandstones to beadpacks. We quantify chaotic advection by measuring Lagrangian stretching statistics (Lyapunov exponent) and its impact on mixing by estimating the decay of solute concentration variance. We find that stretching and mixing rates vary significantly between the different classes of porous architectures. A simple topological model is proposed to explain this behavior.
Aerosol chemistry of the 2021 Fagradalsfjall eruption – following major and trace elements from source to exposed communities
Authors: Ilyinskaya Evgenia , Pfeffer Melissa , Stefansson Andri , Kleine Barbara , Wieser Penny , Liu Emma , Edmonds Marie , Mather Tamsin , Mason Emily , Burton Mike , Barsotti Sara
Published: March 2022

Fissure eruptions are a pollution hazard due to their emissions of gas and aerosol particulate matter (PM) into the lower troposphere, which elevates pollutant concentrations at ground level. Alongside major gas species (e.g., H2O, SO2, CO2) and minute amounts of ash, fissure eruptions emit volatile trace elements including metals and metalloids, typically transported in the atmosphere as fine particulates.

The 2021 Fagradalsfjall fissure eruption in Iceland presented a unique opportunity to better understand volatile emissions and their spread in the atmosphere. During a 5-week campaign inMarch-April 2021, we sampled the plumes from the active vents and the lava flows using ground-based instruments and Unmanned Aerial System (UAS). Size-resolved major (including sulfate and chloride) and trace element aerosol chemistry were analysed using ICP-MS and ion chromatography. We compare the emission rate and magmatic volatility of trace elements between the crater and the lava degassing; and with that of other eruptions globally.

The volcanic plume was also sampled in several downwind areas between 3 and 30 km distance from the eruption site. Using this network, we captured temporal and spatial changes in the major and trace element chemistry of the volcanic plume as it aged.

 
Recent trends in impacts-relevant climate in the world’s Mediterranean-type climate regions 
Authors: Seager Richard , Liu Haibo , Jacobson Tess , Kushnir Yochanan , Simpson Isla R. , Osborn Timothy J. , Nakamura Jennifer
Published: March 2022

Mediterranean-type climate regions are heavily dependent on cool season precipitation for water resources and agriculture.  Declines in cool season precipitation have been noted in the Mediterranean, Chile, southwest South Africa and southern Australia while California has also been experiencing recent droughts.  These changes have been attributed with some confidence to rising greenhouse gases, a poleward shift of storm tracks and Hadley Cell expansion.  However, from the perspectives of climate hazards such as fire and heat and ecosystem impacts, spring and summer climate change are also important.  For example, recent work shows that summer burned area in California’s Mediterranean-type climate depends on winter precipitation but also on precipitation, temperature and vapor pressure deficit in spring and early summer.   Here we consider trends over past decades in the impacts-relevant quantities of precipitation, surface temperature, humidity and vapor pressure deficit throughout the seasons for all the world’s five Mediterranean-type climate regions.  Trends from reanalyses are compared to those from CMIP6 models to attribute changes to radiative forcing and natural variability and the connections between change in thermodynamic quantities and the atmospheric circulation are explored.  We show that across the Mediterranean-type climate regions human-driven climate change throughout the year is generating changes in impacts-relevant climate quantities that will create substantial challenges to societies and ecosystems.
Integration of multiple geoscientific investigation methods for a better understanding of a water system: the example of Chimborazo glaciers melting effects on the Chambo aquifer, Ecuador
Authors: Scozzari Andrea , Catelan Paolo , Chidichimo Francesco , de Biase Michele , Mendoza Trujillo Benito G. , Carrettero Poblete Pedro A. , Straface Salvatore
Published: March 2022

The identification of the processes underlining natural systems often requires the adoption of multiple investigation techniques for the assessment of the sites under study. In this work, the combination of information derived from non-invasive sensing techniques, such as geophysics, remote sensing and hydrogeochemistry, highlights the possible influence of global climate change on the future water availability related to an aquifer in a peculiar glacier context, located in central Ecuador. In particular, we show that the Chambo aquifer, which supplies potable water to the region, does not contain fossil water, and it’s instead recharged over time. Indeed, the whole Chambo river basin is affected by the Chimborazo volcano, which is a glacerised mountain located in the inner tropics, one of the most critical places  to be observed in the frame of climate impact on water resources. Thanks to the infomation gathered by the various surveying techniques, numerical modelling permitted an estimate of the recharge, which can be fully originated by the runoff from Chimborazo melting glaciers. Actually, the retreat of the glaciers on top of the Chimborazo is an ongoing process presumably related to global climate change.
Investigation of climate change impact on olive trees in Tunisia via MODIS LST and NDVI products and correlation measures
Authors: Bounouh Oumayma , Tarquis Ana M. , Riadh Farah Imed
Published: March 2022

Olive trees play a vital role in Tunisia, a North African Mediterranean country. The Mediterranean basin region is experiencing severe climate change conditions. Indeed, traditional olive trees have the distinguishable ability to resist climatic conditions. However, warming trends and unusual both raining, and drought periods are threatening this crop by causing drying phenomenon and decreasing yield’s quality and quantity. Therefore, this culture is attracting great attention for effectively analyzing, and monitoring their changes to cope with the projected changes accurately and put the necessary adaptation strategies. Such work remains a challenge via field measurement approaches. Meanwhile, satellite imagery provides a wide range of data. In this work, we took advantage of MOD13Q1 products to analyze the relationships between vegetation indices and their hidden components and the land surface temperature (LST) for various reasons: Firstly, to assess the relationship between the LST and vegetation indices and their components. Secondly, to determine which temporal profiles are more closely related to each other. Thirdly, to quantify the impact of climate change on olive sites. To this aim, the wavelet transform is used to decompose the time series. Moreover, various similarity and statistical measures are calculated to better quantify these relationships. On one hand, no significant correlation is measured for the trend components. Moreover, the olive trend has shown a positive slope. In contrast, LST depicted negative dynamics. On the other hand, interestingly, the temporal profiles seemed similar. And the wavelet coherence showed a consistent relationship between them. Based on our findings, we remark the limitation of classical correlation measures in depicting the relationship between the discussed variables. Therefore, we conclude that a good causality study must rely on time point relation detection and not on the overall similarity between the environmental variables and the vegetation indices.
Synoptic Drivers of Landfalling Atmospheric Rivers Near Dronning Maud Land, Antarctica
Authors: Baiman Rebecca , Winters Andrew , Lenaerts Jan
Published: March 2022

Atmospheric rivers (ARs) that reach the Antarctic Ice Sheet (AIS) transport anomalous moisture from lower latitudes and can impact the AIS via extreme precipitation and increased downward longwave radiation. ARs contribute significantly to the interannual variability of precipitation over the AIS and thus are likely to play a key role in understanding future changes in the surface mass balance of the AIS. While ARs impact the entire coastal AIS, coastal Dronning Maud Land (DML) is one of four East Antarctic maxima in AR frequency. Along with the high frequency of ARs, the variability of large-scale flow patterns associated with ARs around DML motivates further investigation of synoptic regimes favoring ARs in this region.

 

This study utilizes a self-organizing map (SOM) to identify synoptic-scale regimes associated with landfalling ARs in and near DML. The catalogue of ARs used in this research is output from a detection algorithm developed specifically for Antarctic ARs, and AR landfalls are identified at timesteps in which an AR overlaps with the AIS between 30°W and 30°E. To determine synoptic regimes conducive to AR landfall, sea level pressure anomalies between 60°W and 60°E from MERRA-2 at the time of AR landfalls are used to train a 16 node SOM. Analysis of precipitation attributable to each SOM node reveals three out of the 16 synoptic regimes are responsible for 28% of the AR precipitation despite representing only 24% of the AR timesteps. Subsequent analysis of this SOM will provide insight into the synoptic drivers and thermodynamic characteristics of the synoptic regimes conducive to the most impactful ARs in the region.