bluuebunny/crossref_metadata_2025 huggingface dataset:
Examining the impact of extreme land surface temperature and land cover on heatwave occurrence: The case of MENA region 
Authors: asghariian Mohammadsaeed , Azizi Parvin , Aminzadeh Milad , Shokri Nima
Published: March 2024

The increase in Land Surface Temperature (LST) in a changing climate is expected to alter the intensity and frequency of heatwaves by shifting the energy partitioning over the land surface. The relationship between LST and hot air temperatures, influenced by land cover and associated changes in surface properties is not fully understood, particularly in dry regions of the world experiencing prolonged droughts. Extremely high LSTs and their projected changes [1] may stress resilience and adaptive capacities of the growing population in the Middle East and North Africa (MENA). We thus investigate the evolution of extremely high LSTs in MENA over the past two decades to identify its coupling with hot air temperatures considering different land cover types. Our preliminary results highlight the difference in warming rates of LST and air temperature across different land covers thus enabling to identify the role of land temperature extremes in triggering heatwave events. We observed that variation of land temperature arising from land cover changes (affecting soil moisture dynamics and surface thermal and radiative properties) may significantly influence the occurrence and the intensity of heatwaves in this region. The study offers valuable insights into the complex interplay between land and air hot extremes that are particularly important in local climate investigations, agricultural practices, and ecosystem functions.Reference[1] Aminzadeh, M., Or, D., Stevens, B., AghaKouchak, A., & Shokri, N. (2023). Upper bounds of maximum land surface temperatures in a warming climate and limits to plant growth. Earth's Future, 11, e2023EF003755. https://doi.org/10.1029/2023EF003755
Comprehensive two-dimensional structural-geological model of the Nazca Ridge subduction zone
Authors: Ciattoni Sara , Cella Federico , Mazzoli Stefano , Zambrano Miller , Butler Robert , Santini Stefano , Megna Antonella , Di Celma Claudio
Published: March 2024

The Nazca Ridge's thickened subduction beneath the South American continental margin (10° to 15° S) is characterised by a flat-slab configuration. This peculiar geological setting strongly influences upper plate dynamics, significantly impacting stress distribution and seismicity in the South American plate. However, the effects of the Nazca Ridge subduction on the Peruvian forearc and Andean Cordillera development remain subjects of extensive debate. In this study we thoroughly investigate the general structure of the Nazca Ridge subduction zone producing an integrated two-dimensional structural-geological model of the south-Peruvian Andes. Combining surface geological data and geophysical information from existing literature, we delineated the crustal structure up to a depth of about 130 km along a ca. 1000 km-long transect, encompassing the Peruvian Forearc System and the Andean Cordillera. In order to improve the characterization of geological features and validate the model, we carried out forward modelling of the Bouguer anomaly in the region, integrating four distinct datasets. Subsequently, we formulated a two-dimensional density model to reproduce the observed gravity field, taking into consideration the petrological properties of the materials and the P-T condition in each area of the crustal section. The geometry of the structures was assessed by choosing the configuration that, honouring the geological and geophysical constraints upon which the initial model was based, also allowed maximising the fit between observed Bouguer anomaly values and the values computed during the forward modelling process. Our exhaustive approach allowed us to obtain a comprehensive model of the Nazca Ridge subduction zone, accurately defining both the deep lithosphere-asthenosphere system and shallow geological structures. This contribution will substantially enhance the ongoing debate on the tectonic evolution and geodynamics of Andean orogeny.
Distinguishing cooling histories via Diffusion Geospeedometry
Authors: Moulas Evangelos , Stüwe Kurt
Published: March 2024

Extracting apparent timescales or cooling rates of rocks via inverse diffusion modelling allows the testing of geodynamic consequences on the petrological record.  Indeed, inverse modelling of diffusion in minerals such as garnet has been used extensively to constrain thermal history timescales [1] and/or cooling rates [2]. Although inherently such models do not have unique solutions, [3], they can be used to place constraints on the thermal history of rocks and regions [4].This is interesting because different geodynamic processes will have thermal histories with different attributes [5], in particular qualtiative differences in the shape of cooling curves. In this contribution, we investigate aspects of different apparent cooling rates extracted via inverse diffusion modelling in garnet. Our results suggest a clear distinction in thermal history depending on wether the rocks experienced “active” (driven from tectonic forces) or “passive” (purely conductive) cooling [5]. We emphasize that active cooling implies slow cooling rates at high-grade conditions whereas passive cooling can have very large cooling rates at high-grade conditions (Fig. 1). For petrologic systems with relatively high closure temperatures (>400 °C), the spatially varying aparent cooling rates allow the identification of local heat sources such as intrusions or heat-producing shear zones (Fig. 1). Our results help to identify processes that have transient and local characters such as the thermal affects of heat-producing shear zones and magmatic intrusions. Figure 1 – (a) Thermal histories from rocks in the vicinity of a shear zone, note the higher temperatures experienced by the shear-zone rocks. Such thermal histories will lead to spatial gradients of diffusion relaxation. (b) Absolute cooling rates as a function temperature for the curves shown in (a). The cooling rate versus temperature curve was calculated considering the thermal histories shown in (a) for the time period after 1Myr. (after [2]). REFERENCES[1] Chakraborty, S. Diffusion in Solid Silicates: A Tool to Track Timescales of Processes Comes of Age. Annu. Rev. Earth Planet. Sci. 36, 153–190 (2008).[2] Burg, J.-P. & Moulas, E. Cooling-rate constraints from metapelites across two inverted metamorphic sequences of the Alpine-Himalayan belt; evidence for viscous heating. J. Struct. Geol. 156, 104536 (2022).[3] Moulas, E. & Bachmayr, M. Petrology as an ill-posed inverse problem. in 73 (Mainz Institute of Multiscale Modelling, 2023).[4] Braun, J., Beek, P. van der & Batt, G. Quantitative Thermochronology: Numerical Methods for the Interpretation of Thermochronological Data. (Cambridge University Press, 2006). doi:10.1017/CBO9780511616433.[5] Stüwe, K. & Ehlers, K. Distinguishing Cooling Histories using Thermometry. Interpretations of Cooling Curves with some Examples from the Glein-Koralm Region and the Central Swiss Alps. Mitteilungen Österr. Geol. Ges. 89, 201–212 (1998).
Characteristics of Warm‐Season Mesoscale Convective Systems Over the Yangtze–Huaihe River Basin (YHR): Comparison Between Radar and Satellite
Authors: Lu Yutong , Tang Jianping , Xu Xin , Tang Ying , Fang Juan
Published: March 2024

Mesoscale convective systems (MCSs) are crucial in modifying the water cycle and frequently induce high-impact weather events over eastern China. Radar and Climate Prediction Center (CPC)-4 km satellite-derived infrared cloud top temperature (Tb) data were used to thoroughly analyze the long-term climatology of MCSs over eastern China, particularly in the Yangtze–Huaihe River Basin (YHR) in the warm season from 2013 to 2018. For the first time, we contrasted the effects of data set selection and threshold setting on research outcomes. The large-scale environments of MCSs initiation were also investigated using the latest global reanalysis data ERA5. It is found that striction of thresholds, including duration, reflectivity/Tb, area, and linearity, would lead to a greater proportion of early-morning MCSs. Satellite-identified MCSs differed from radar-derived ones, exhibiting afternoon diurnal peaks, faster movement speeds, longer travel distances, and expansive impact areas. The center of MCS and related precipitation shifted northward from Pre-Meiyu to Post-Meiyu seasons, contributing to up to 20% of total rainfall, with most MCSs moving along eastward trajectories. MCSs typically had the most substantial impact in the Meiyu season because of the most prolonged duration, largest convective core area, and strongest precipitation intensity. Warm-season MCSs initiated ahead of midlevel troughs and were related to strong anomalous low-level convergence and midlevel upward. The circulation anomalies were the strongest in the Pre-Meiyu season among the three subseasons, with most moisture sourced from the southwest.
Effects of conservation tillage on soil organic carbon storage, fractions and stability in Black soil
Authors: Zhang Yan , Liang Aizhen , Zhang Xiaoping , Li Xiujun , Gregorich Edward , McLaughlin Neil
Published: March 2024

In Northeast China, conventional tillage practices involve removal of crop residue after harvest and prior to moldboard plowing; this has been shown to cause a decline of soil organic carbon (SOC) and degradation of Black soils (Mollisols). Conservation tillage, particularly no tillage (NT), has been suggested to be an effective practice to control soil erosion and increase the SOC content. Hence, we established an experiment (since 2001) to evaluate how a combination of different tillage and cropping systems could improve SOC in black soils. The total SOC storage, SOC fractions (physical and chemical), SOC stability were assessed to evaluate the effects of tillage and cropping system. Our results shows that: 1) different tillage and cropping system combinations had different effects on SOC storage; NT combined with continuous maize had the highest SOC storage among all treatments; 2) The effects of tillage on aggregate size and OC concentration mainly occurred in the surface layer (0–5 cm) while the effect of cropping system on aggregate size and OC concentration mainly occurred at deeper depths; 3) NT increased the recalcitrant carbon pool in surface layer showing the critical need for returning crop residues to maintain long-term SOC storage; 4) SOC mineralization (biological stability) appears to be related to the SOC proportion in the light fraction; 5) More than half of the increase in SOC storage due to NT existed as microbial necromass carbon storage under continuous maize which was higher than maize-soybean rotation. Our study shows that in black soils (Northeast China), NT and appropriate cropping systems can not only halt soil degradation caused by poor management but can induce substantial increases in SOC which is beneficial for SOC long-term sequestration.
The intensity distribution of Terrestrial Gamma-ray Flashes from the ALOFT flight campaign
Authors: Fuglestad Anders ,   ALOFT team
Published: March 2024

In July 2023, the Airborne Lightning Observatory for FEGS and TGFs (ALOFT) flight campaign took place using a NASA ER-2 research aircraft flying over the Gulf of Mexico and the Caribbean Sea. The campaign consisted of about 60 flight hours at a cruise altitude of 20 km, using live telemetry to target gamma-ray glowing thunderclouds.The payload consisted of several instruments including gamma-ray detectors with a dynamic range spanning four orders of magnitude in flux, an imaging array of optical photometers, electric field change meters, radiometers, and radar systems. In addition to several ground stations measuring very low frequency, low frequency, and very high frequency radio signals.96 TGFs were detected by ALOFT. For 44 of these events, it was possible to get an estimate of the location of the source using both correlated optical pulses and lightning detection networks.With the estimate of the source location and the gamma-ray observation from ALOFT. Monte Carlo simulations were used to get an estimate of the source intensity of the TGFs.Based on the results it was determined that the vast majority of the 44 TGFs investigated have source intensities below the threshold needed to be observed from current satellite instruments, which indicates a large population of low intensity TGFs that has gone previously undetected. These results contribute to the open debate on the rarity of TGFs.
Effects of soil phosphorus on root exudates in central Amazonia
Authors: Reichert Tatiana , Fuchslueger Lucia , de Andrade Sara A. L. , Bauerle Taryn , Borghi Alexandre , P. Darela-Filho João , Fleischer Katrin , Hafner Benjamin , Hartley Iain P. , Di Ponzio Raffaello , A. Quesada Carlos , Rammig Anja , Schmeisk Jessica , Lugli Laynara F.
Published: March 2024

Plants in tropical forests are thought to allocate a substantial portion of their photosynthetically fixed carbon (C) to the rhizosphere as exudates. These exudates serve multiple functions, including the mobilization of soil nutrients such as phosphorus (P), which is crucial for plant growth. In Amazonia, the predominant soils have notably low P concentrations, and plants likely employ a variety of strategies for P acquisition. However, the role of root exudates in P-impoverished Amazonian soils has not been empirically explored so far. To fill this gap, we investigated the largely uncharted territory of root exudation, as part of the Amazon fertilization experiment (AFEX), in a mature tropical forest growing on highly-weathered P-impoverished soils of central Amazonia. Our research examined root exudation in situ, both under natural soil conditions and P addition. We assessed the concentration of total organic carbon (TOC), total nitrogen (TN), and a suite of organic acids in root exudates, as well as additional root physiological and morphological traits of relevance, to potentially explain the variability in root exudation rates.Our study revealed higher root exudation rates of TOC and organic acids in control, compared to P-addition plots, which suggests that plant C allocation to root exudates is an adaptive response to P availability. We also found that root exudation traits align with various morphological and physiological traits within the root economic space. Our findings provide insights into the hidden dynamics of root-soil interactions and have significant implications for understanding C cycling in tropical forests, shedding light on the complex coordination of root P acquisition strategies under different soil P conditions. 
Reconstructing historical ocean changes around the West Antarctic Ice Sheet over the past centuries
Authors: Dalaiden Quentin , Holland Paul , Naughten Kaitlin , Mathiot Pierre , Pirlet Noé , Barthelemy Antoine , Jourdain Nicolas
Published: March 2024

Over recent decades, the West Antarctic Ice Sheet (WAIS) has witnessed a large increase in ice shelf melting. This ice loss is recognized to be associated with a response to changes in the ocean state, in particular of the Circumpolar Deep Water (CDW) on the Amundsen Sea continental shelf. It has been shown that the variability of the CDW inflow is strongly related to wind changes. While instrumental-based atmospheric reanalysis products are available since 1979, given the strong natural variability of the West Antarctic climate, this period of a few decades might be too short to identify the mechanisms driving the long-term changes in ice shelf melting, and to distinguish the relative contribution of natural and forced variability to the total changes. Therefore, there is a need to provide long-term historical changes in oceanic conditions to put the recently observed ice shelf melting into a longer context and to ultimately better constrain the future contribution of the WAIS to the global sea-level rise. Over the past few years, atmospheric reanalysis based on paleoclimate records spanning the last centuries have been released. This offers us the opportunity to assess historical changes in oceanic conditions in response to changes in the atmosphere. In this study, we propose a framework to reconstruct past ocean conditions around the WAIS over the last few centuries by using an ocean–sea-ice model (NEMO-SI3) forced by a paleo-based atmospheric reanalysis. Specifically, we use a paleo-reanalysis based on data assimilation that aims at dynamically combining information from paleoclimate records from the Southern Hemisphere (especially ice-core records) and the physics of Earth System Models. This has the advantage of guaranteeing a dynamical consistency between the reconstructed variables. Along with the methodology, we present the first reconstructed oceanic conditions from the NEMO-SI3 simulations.
Using Oil & Gas Borehole Data to Unlock the Geothermal Potential of the Dogger Sandstone in the North German Basin
Authors: Weber Immanuel , Tischner Torsten
Published: March 2024

In Germany, the geothermal development takes place at different speeds regionally. Compared to the Molasse Basin in South Germany, the North German Basin is just at the beginning of its geothermal exploration.The project “Warm-Up” aims to evaluate the geothermal potential in the North German Basin and to promote its geothermal development. One target for detailed investigations are the sandstones of the Dogger. This Jurassic reservoir with nearly full extent in the North German Basin was a worthwhile target for the Oil Industry based on its reservoir quality and its oil content. A large volume of data, including geological and lithological one, with special focus on hydraulic data, porosity-permeability relationships and their links to the facies have been evaluated. Where core data is not available, the extraction of hydraulic properties from well logs is necessary. Different methods for deriving porosity and permeability from well logs are tested and checked against core data. If hydraulic test results are available the comparison of those in-situ data to logging and core measurements is of crucial importance. In reality, a full set of logging, core and test data is only available in a few wells, despite the large effort, taken by the hydrocarbon industry in the past. Therefore, it is important to develop workflows, that allows the prediction of the productivity of the Dogger sandstones in areas with fewer data and to reduce the exploitation risk. Companies like local municipal utility or majors can utilize this knowledge to unlock the geothermal potential of the North German Basin.
Mantle transition zone anomalies beneath Iberia and NW Maghreb
Authors: Parera Portell Joan Antoni , Mancilla Flor de Lis , Morales José , Díaz Jordi
Published: March 2024

The 410 and 660 discontinuities are predicted to be the result of isochemical phase changes in olivine. The differing Clapeyron slope of the reactions, though, leads to opposite 410 and 660 behaviour for a same temperature variation, with cold and hot mantle anomalies resulting in a thicker or thinner transition zone (MTZ), respectively. Here we use more than 56500 high-quality P-wave receiver functions obtained from 881 broadband seismic stations to locate anomalies in the MTZ beneath Iberia and NW Maghreb. We obtained robust maps of the 410 and 660 discontinuity depth thanks to the combined measurements of several 3D depth migrations using regional and global P-wave tomography models, and used these maps to calculate the MTZ thickness. Our results reveal several large-scale anomalies in the region mostly linked to the thermal effects of cold subducted slabs, but we also found evidence for significant chemical heterogeneity in the MTZ. The Gibraltar-Alboran and Alpine-Tethys slabs cause a continuous MTZ thickening along the Mediterranean coasts. Accompanying the slab anomalies are up to three areas with a low-velocity layer (LVL) located at the top of the 410 discontinuity, which provide evidence for partial melting coinciding with an MTZ enriched in water due to slab dehydration reactions. A similar LVL is also found at the top of the lower mantle where the Alpine-Tethys slab pushes the 660 discontinuity downwards. Mantle upwelling occurs at the back of the Gibraltar-Alboran slab, where we find the thinnest MTZ in the region. Upwelling hot materials seem to travel SW following a toroidal flow along the southern boundary of the slab and cause the 410 discontinuity to deepen significantly. Even though the MTZ thickness remains near-standard, the 410 also deepens in a more discontinuous manner beneath the Atlas Mountains. The active anorogenic volcanism in the Western Mediterranean correlates remarkably well with the LVL on top of regions with sunken 410, possibly pointing at a MTZ source for the melts.
Influence of Intraseasonal Variability of Sea Surface Temperature in the Arabian Sea on the Summer Monsoon Precipitation Over the Bay of Bengal
Authors: Xi Jingyuan
Published: March 2024

Summer monsoon precipitation over the Bay of Bengal (BoB) has pronounced intraseasonal variability (ISV), which has a close relationship to the local intraseasonal sea surface temperature (SST). Before heavy precipitation, intraseasonal SST in the BoB often has a warm anomaly and propagates northward, which drives the atmosphere and tends to trigger the convection. Besides the local air-sea interaction, the ISV of SST in the Arabian Sea (AS) also has an effect on the precipitation over the BoB. Results show that a prominent heavy precipitation usually occurs when the warm intraseasonal SST anomaly appears early in the AS and moves northward prior to that emerges in the BoB. The warm SST anomaly in the AS affects the sea level pressure and then trigger a southwestly wind anomaly in the center of AS. This wind anomaly promotes the wind convergence moving northward from the southern tip of Indian peninsula to the north India and northern BoB, which directly influence the vertical moisture advection and finally the precipitation. Understanding this process will be helpful to improve the predictive skill of the ISVs during the Indian Summer Monsoon.
Enhancing groundwater recharge in face of hydrological extremes: assessment of stormwater managed aquifer recharge potential in Flemish drinking water protection zones (Belgium)
Authors: Speijer Lara , Six Simon , van der Grift Bas , Cirkel Gijsbert , Verreydt Goedele , Dams Jef , Huysmans Marijke
Published: March 2024

Flanders (Belgium) is expected to experience more severe drought and flooding events in face of climate change. Infiltration to increase groundwater recharge is therefore adopted as policy strategy to deal with both hydrological extremes. Stormwater provides an interesting water source for managed aquifer recharge, given the high urbanization and imperviousness level of the region. Furthermore, the historical ban on infiltration in groundwater protection zones for drinking water production has been removed to encourage infiltration practices. This could potentially enhance groundwater recharge in the groundwater abstraction zones, but concerns remain regarding the impacts on groundwater quality due to the potential contamination of stormwater with a wide range of pollutants originating from traffic, building materials, weed control and other more diffuse sources.Therefore, tools need to be developed to weigh out benefits of groundwater replenishment relative to potential groundwater quality risks. This research aims to contribute to the knowledge on the hydrological aspects of this quantity-quality balancing exercise by investigating the potential of stormwater managed aquifer recharge to replenish the groundwater system in Flemish groundwater protection zones. For this, potential stormwater volumes that could supply managed aquifer recharge are calculated and compared to the actual groundwater recharge and pumping volumes for drinking water production to assess the significance of this practice in protection zones.Results indicate a variable, but high stormwater infiltration potential in Flemish protection zones, providing up to 29% extra groundwater recharge in all protection zones combined. Furthermore, this practice could compensate up to 32% of abstracted phreatic drinking water volumes. Locally, the potential can be higher, reaching 100% in protection zones located in highly urbanized areas, including zones around the city of Leuven. Stormwater infiltration can therefore be considered as an important drought adaptation measure in Flemish protection zones, given the same order of magnitude of stormwater and pumping volumes in these areas. However, recent studies raise concern on the occurrence of organic micropollutants in stormwater and data in the Dutch and Flemish setting is insufficient. Therefore, additional research on occurrence and fate of these substances is needed.
Monitoring two-phase fluids in geothermal fields using seismic noise interferometry
Authors: Sánchez-Pastor Pilar , Wu Sin-Mei , Hokstad Ketil , Kristjánsson Bjarni , Drouin Vincent , Ducrocq Cécile , Gunnarsson Gunnar , Rinaldi Antonio , Obermann Anne , Wiemer Stefan
Published: March 2024

Harvesting geothermal energy often leads to a pressure drop in reservoirs that promotes the formation of steam. In some reservoirs, steam coexists with liquid water forming two-phase fluids, as happens in the Hengill geothermal field. This field is located in a triple junction of three large tectonic features in Iceland, 30 km east of the capital Reykjavik. The accumulation of steam in the top part of the reservoir forms a so-called steam cap. While steam caps are valuable energy resources, they also alter the reservoir thermodynamics and entail diverse risks such as land subsidence. Therefore, monitoring the steam content in reservoirs is essential for both operational and economic perspectives. However, this is an inherently challenging task and quantifying the steam content from indirect and surface-based measurements is still an unsolved matter.Here, we present a new method for indirectly sampling the steam content in the subsurface using the ever-present seismic background noise. We analyse the seismic velocity changes in the area, estimate the land subsidence via Interferometric Synthetic Aperture Radar (InSAR) and work with in situ borehole data. We observe a consistent annual velocity drop in the Hengill geothermal field and establish a correlation between the velocity drop and steam buildup. This study introduces seismic noise interferometry as a powerful tool for monitoring two-phase fluids in the crust with minimal infrastructure, only one seismic station. Beyond geothermal sites, the methodology could extend to diverse geological settings, such as volcanoes, CO2 storage sites, hydrocarbon reservoirs, among others.
Orbit parameterization aspects in global solutions of spherical Laser Ranging Satellites
Authors: Meyer Ulrich , Geisser Linda , König Daniel , Dach Rolf , Thaller Daniela , Jäggi Adrian
Published: March 2024

Laser ranging to spherical satellites is a major source for the determination of geophysical and geometric parameters like the scale of the reference system and the lowest degree (1-2) gravity field coefficients, i.e. geocenter motion, dynamic oblateness and the orientation of the rotation axis of the Earth. The International Laser Ranging Service (ILRS) is collecting Satellite Laser Ranging (SLR) observations of a global station network, providing the range data as normal points to its analysis centers, which perform precise orbit determination (POD) and network solutions based on 7 day orbital arcs. Currently, efforts are undertaken to extend the classical ILRS processing of the LAGEOS and ETALON satellites by LARES 2, as well as lower-flying satellites, i.e. LARES, Stella and Starlette, necessitating an adaption of the SLR-POD model and parametrization due to the increased sensitivity to orbit perturbations at low orbit altitudes.We present the status of the SLR-POD at AIUB, where in support of the ILRS analysis center at BKG the incorporation of the low-flying SLR satellites into the 7 day POD and network solution of LAGEOS/ETALON/LARES-2 is beeing tested, making use of long-arc stacking techniques of daily arcs to continuous 7 day arcs. All orbit and geophysical parametes are estimated in one common estimation process to avoid implicit regularization by apriori information. Special attention is paid to the co-estimation of the low-degree gravity field coefficients and the correlations with the empirical dynamic parameters deployed in the classical LAGEOS/ETALON POD model.
Thermo-poro-elastic effects induced by fluid flow can explain the recent seismicity and deformation at Campi Flegrei (Italy)
Authors: Nespoli Massimo , Tramelli Anna , Belardinelli Maria Elina , Bonafede Maurizio
Published: March 2024

Thermo-Poro-Elastic (TPE) inclusions are suitable to model the mechanical effects induced by hot and pressurized hydrothermal fluids pervading a closed volume of rocks. In fact, modeling of TPE deformation sources finds application in both geothermal and vulcanological fields. Some recent works showed that a cylindrical TPE inclusion located at about 2 km of depth contributed to the large and rapid soil uplift observed during the ‘82-’84 unrest phase in the Campi Flegrei caldera. In the present work, we demonstrate that such a source of deformation can be responsible for a significant contribution even in the current unrest phase, that started in 2005 and it is still in progress. We show that the time-series of soil uplift observed in the last years can be reproduced by assuming the rising of hot and pressurized fluids, possibly exsolved by a deep magmatic source, within the same deformation source responsible of the ‘82-’84 unrest. The existence of such a TPE inclusion at Campi Flegrei was supported by previous tomographic studies and it is reinforced by the new analysis of the b-values. In fact, we found a sharp variation of the b-value in correspondence of the depth of the modelled TPE inclusion. The decrease of the b-values is consistent with the fact that within the TPE inclusion the induced shear stress is maximum and the occurrence of larger earthquakes is favored. The results support the existence and the importance of the mechanical effects of fluids flow, during the unrest phases of the Campi Flegrei caldera.
Using personal weather station data for improving precipitation estimates and gauge adjustment of radar data
Authors: Seidel Jochen , Einfalt Thomas , Jessen Markus , Bárdossy András , El Hachem Abbas , Treis Adrian
Published: March 2024

Personal Weather Stations (PWS) are simple, low cost meteorological instruments that can be set up by private persons or companies. In Central Europe, the number of PWS has increased significantly over the last years, in the meantime clearly outnumbering the number of rain gauges operated by national weather services and other authorities. However, the data from PWS suffer from many drawbacks since these stations are not set up and maintained according to professional standards. Apart from this, there are additional sources of errors and uncertainty originating from data transmission errors and incorrect information about the location of a PWS. Hence, the precipitation data from PWS has to be filtered and corrected before this information can be used e.g. for improving precipitation interpolation. Such algorithms have been developed e.g. by de Vos et al. (2019) and Bárdossy et al. (2021).In the area of the water boards Emschergenossenschaft and Lippeverband (EGLV), investigations were carried out to determine whether data from private weather stations (PWS) can improve the interpolation of rainfall fields and if PWS can be used for the gauge-based adjustment of radar data. The area of the EGLV is located in a densely populated area in the federal state of North Rhine-Westphalia, where there is also a large number of PWS available. Furthermore, the EGLV operates a dense rain gauge network which is required for the quality control (QC) algorithm by Bárdossy et al. (2021) which was used in this study.The results show that the additional information from PWS can capture the spatial structures of precipitation better than a standard measurement network alone. However, the spatial resolution and the maxima of the radar data are not achieved, especially in areas with low PWS density. Another aspect that was investigated is the question whether individual PWS can be used for the gauge adjustment of radar data. In principal, individual quality controlled PWS can be used for this purpose, there are however issues due to data gaps and the underestimation of hourly precipitation maxima, which currently limits the use of PWS for commonly used gauge-adjustment procedures.ReferencesBárdossy, A., Seidel, J., and El Hachem, A. (2021), The use of personal weather station observations to improve precipitation estimation and interpolation. Hydrol. Earth Syst. Sci., 25, 583–601.de Vos, L., Leijnse, H.,Overeem, A., and Uijlenhoet, R. (2019), Quality control for crowdsourced personal weather stations to enable operational rainfall monitoring. Geophysical Research Letters,46,8820–8829. 
Constraining Mantle Convection Patterns by Joint Geodynamic and Seismological Modelling
Authors: Faccenda Manuele
Published: March 2024

The study of the Earth’s interior has been traditionally based on seismological and geodynamic modelling, the first one providing important information about its present-day structure, composition and state, while the second about its dynamics and compositional evolution. Seismological and geodynamical modelling are very often conducted independently, which creates mechanical and geometrical inconsistencies across the models, hampers the interpretation of seismic observations in terms of geodynamic processes and enhances the non-uniqueness of geodynamic model predictions.An alternative approach is combining computational seismology and geodynamics with mineral physics, which provides a comprehensive understanding of the Earth's interior processes, seismic behavior, and material properties. In this multidisciplinary methodology, the geodynamic flow calculations are used to compute the rock elastic properties as a function of strain-induced mantle fabrics through micro-mechanical models of crystal aggregate deformation, and of the local P-T conditions with thermodynamically self-consistent models of mantle mineralogy. The obtained seismic mantle structure is then used for seismological synthetics, such that specific hypotheses on mantle dynamics can be tested directly against seismic data. Examples from the South American, North American, and the Central Mediterranean convergent margins will be discussed.Finally, I will introduce ECOMAN, a recently developed, open-source software package that is intended to overcome the computationally intensive nature of this approach and the lack of a dedicated and comprehensive computational framework for modelling strain-/stress-induced rock fabrics and testing the effects of the resulting mechanical (elastic and viscous) anisotropy on seismic imaging and mantle convection.
Compounding drivers amplify the severity of river floods 
Authors: Jiang Shijie , Tarasova Larisa , Yu Guo , Zscheischler Jakob
Published: March 2024

Estimating the risk of river flooding under global warming is challenging, mainly due to the compound nature of the various drivers, which is not yet fully understood. Our study aims to quantitatively unravel the complex dynamics of multiple factors that interact and influence river flooding. Using interpretable machine learning techniques, we analyzed thousands of global catchments to identify the role of compounding drivers in river flooding. Our results indicate that these compounding drivers have played a significant role in increasing the magnitude of river floods over the past four decades. In particular, the influence of the interaction effects between these drivers becomes more pronounced with increasing flood magnitude, and the degree is modulated by specific physioclimatic conditions. Importantly, traditional flood analysis will underestimate the magnitude of extreme floods due to insufficient consideration of the varying compounding effects in flood generation. Overall, our results emphasize the need to more carefully incorporate compounding factors to improve extreme flood estimates.
Modeling geoid and dynamic topography from tomography-based thermo-chemical mantle convection with temperature- and depth-dependent viscosity
Authors: Cui Ronghua , Steinberger Bernhard , Fang Jian
Published: March 2024

Mantle convection causes the most important contribution to the geoid and dynamic topography. With high resolution tomography models and numerical simulation methods solving the governing equations of mantle convection, the model geoid can fit well compared to observation. However, if wave speed variations are converted to density variations assuming both are due to temperature variation in the entire mantle, there is still a large discrepancy between the present dynamic topography predicted by mantle flow and that induced from observations: Especially large negative topography is predicted in cratons, contrary to observations. In order to improve the fit of model dynamic topography compared to observations, chemical density anomaly in earth’s lithosphere need to be included. In this study, we will combine these with lateral viscosity structure and study the effect on model dynamic topography and geoid, and investigate which density models would yield a good fit. In the sublithospheric mantle, under the assumption that the density anomalies are thermally induced from temperature variation in the mantle, we use temperature-dependent viscosity. We also include thermo-chemical density anomalies in the Large low-shear-velocity provinces (LLSVPs) in the lowermost mantle to compute their effect on the model geoid and dynamic topography. Our overall objective is a better constraint on the Earth’s interior structure, by achieving good fits of both dynamic topography and geoid to their observations, to provide as a good reference for the Earth’s study.
Response of two coastal peatlands to the duration of rewetting and the release of nutrients
Authors: Voss Maren , Breznikar Anne , Liskow Iris , Poenisch Daniel , Rehder Gregor
Published: March 2024

Along the German coastline of the Baltic Sea are numerous former coastal fens. The originally approx. 40,000 hectares of peatland that were regularly flooded are now mostly diked, drained and are mainly used for agriculture. In order to be prepared for rising sea levels in the future, attempts are being made to determine the consequences of renewed flooding for the development of the fen and the adjacent Baltic Sea. A first test area was a former peatland in Drammendorf on the island of Ruegen, Germany. It had been rewetted in a major campaign lead by the Baltic Sea Foundation. The other area, Karrendorf, had been flooded already 30 years ago. The two coastal fens had different periods of waterlogging and were studied comparatively over the course of a year. In addition to the typical seasonality, which is reflected in the same temperature and oxygen content at both sites and the adjacent bays, there are striking differences in nutrient concentrations and isotope signatures of organic matter and nitrate, some of which can be traced back to the history of the areas as agricultural land. Shortly after its rewetting in winter, for example, nitrate concentrations in Drammendorf were several times higher than in Karrendorf and nitrous oxide saturations were up to 4000 %.We found that the longer the area was flooded and nutrients released to the overlying waters, the less nutrients are discharged into the adjacent Baltic Sea. This finding was not only reflected by lower nutrient concentrations in the surface water of Karrendorf, but also in much lower porewater nutrient concentrations. Moreover, we saw a close coupling of the microbial processes in the overlying water with the soils. Nitrification, which converts ammonium from decomposition processes into nitrate, was clearly recognizable in the nitrogen and oxygen isotopes of nitrate despite low rates. However, high δ18O values of nitrate indicate precipitation as another possible source of nutrients. In addition, the isotope values of the organic matter show that there is an intensive exchange between the Baltic Sea and the coastal fens, whereby Drammendorf is more strongly characterized by marine organic matter inflow than Karrendorf. Thus, the flooding of coastal peatlands initiates lateral transport across the terrestrial-marine interface, while the microbial processes play more of a role in the interaction between soil and water.For future management, the soil composition and history should always be considered and the intensity of exchange with coastal waters taken into account so that these areas do not become hot spots of eutrophication due to their large nutrient reservoirs.
Spatiotemporal Impacts of Aerosols on Cloud Properties and Precipitation Patterns in South Asian Monsoon Region: Contrasting High and Low Precipitation Years.
Authors: Khattak Palwasha , Cermak Jan , Fatima Syeda Hira , Fuchs Julia
Published: March 2024

This study investigates the relationship between aerosols and cloud properties in the South Asian monsoon over two decades, using satellite data. We conducted a 20-year analysis of aerosols and diverse cloud properties during the monsoon months. Precipitation patterns were categorized into high and low years based on anomalies. Significant correlations emerged between aerosol optical depth (AOD) and cloud properties, including cloud fraction, cloud droplet size, cloud top features, column-integrated water vapor, ice water path, and liquid water path. AOD and cloud fraction showed positive correlations, though not always translating to increased precipitation, underlining the role of cloud microphysics. AOD influenced cloud droplet size differently across regions, with some showing smaller droplets with higher AOD. Cloud height, temperature, and reflectivity were affected by AOD, indicating its influence on cloud properties through droplet concentration. Column-integrated water vapor positively correlated with AOD, implying aerosol involvement in water vapor condensation into cloud droplets. These findings uncover the intricate regional dynamics of aerosol-cloud interactions during the South Asian monsoon, offering valuable insights into the delicate relationships between aerosols, cloud properties, and precipitation variations across the diverse landscape of South Asia. This underscores the significance of considering regional variations in aerosol-cloud interactions when evaluating their impact on South Asian monsoon systems.
Understanding corrosion and carbonation effects on pore scale properties of geological reservoir rocks during CO2 injection and storage: Insights from X-ray Computed Tomography 
Authors: Macente Alice , Piazolo Sandra , Pessu Frederick Oritseweneye
Published: March 2024

Carbon capture and storage (CCS) holds the potential to mitigate carbon dioxide (CO2) emissions into the atmosphere. However, there is a likely accumulation of impurities generated from the corrosion reaction taking place within the pipelines during the injection process as well as during the transportation phase. Reactions can change the chemistry of injected fluids for storage, which can then react with the adjacent rock formations reservoir, affecting the reservoir porosity, permeability and caprock integrity. These are important parameters that determine the injectivity and storage capacities of deep geological sites for long term CO2 storage. The study is aimed at evaluating the upstream corrosion of the metallic pipeline materials, correlating their kinetics with changes in the injection fluid chemistry and evaluating the effect of these combined phenomena on the storage capacities of the geological reservoir rocks. The study involves the investigation and characterisation of corrosion and bulk scaling upstream to the deep geological formations of various rock types. Reservoir rock samples are characterised before corrosion and after carbonation reactions using X-ray Computed Tomography and other micro-analytical techniques, to assess the changes in the rock storage capacity properties such as porosity, pore connectivity and permeability. Our preliminary results indicate an increase in porosity, pore size and pore connectivity in pure sandstones compared to impure sandstones, indicating that local rock chemistry in an important factor in controlling dissolution/carbonation kinetics.
Viscous-Flow-to-Fracture Transition in Linear Maxwell Fluids vs. Yield-Strength Materials: Implications for Magma Fracturing and Acoustic Emission
Authors: Sánchez Claudia , Ichihara Mie , Muramatsu Dan
Published: March 2024

During magma ascent, the growth, ascent, and bursting of bubbles play a pivotal role, intricately linked with the rheological properties of magma. In the realm of this complexity, viscoelasticity stands out as a crucial factor influencing infrasound generation resulting from bubble bursting in volcanic systems. The linear Maxwell model, a fundamental representation of magma viscoelasticity, serves as a starting point for our investigation.In this study, we explore acoustic wave generation induced by bubble bursting in two distinct fluids: a Maxwell-type viscoelastic fluid (CTAB) and a Bingham-type yield-strength fluid (GEL). Despite both fluids exhibiting similar rigidity in the linear elastic regime, their fracture and flow behaviors diverge significantly. The acoustic signals generated by these fluids display pronounced variations, contingent upon factors such as flux (Q) and the depth of air injection (h).In the case of CTAB, bursting sounds are observed exclusively in the brittle regime at elevated Q, characterized by successive fractures within the fluid. At shallow injection depths, these fractures extend from the nozzle to the fluid surface, creating distinct acoustic waves. Deeper air injection results in crack growth, detachment from the nozzle, ascent to the surface, and subsequent acoustic wave generation. Interestingly, a round cavity, exclusive to small Q, does not produce acoustic waves.In contrast, GEL consistently forms a round air cavity, with the initial bursting being silent within the same range of Q and h as observed in CTAB. Brittle fractures are notably absent, and acoustic wave generation occurs only with continued air injection, indicating that rigidity alone does not dictate bursting sound; rather, it hinges on fluid brittleness and gas-flow conditions, including rate, depth, and injection history. This experimental exploration sheds light on the nuanced interplay between fluid properties and gas-flow dynamics in the context of acoustic wave generation during bubble bursting.           
A pattern recognition approach to generate soil process units for ecosystem modeling
Authors: Ließ Mareike
Published: March 2024

The landscape-scale evaluation and modeling of the impact of agricultural management and climate change on soil-derived ecosystem services requires soil information at a spatial resolution addressing individual agricultural fields. A pattern recognition approach is presented that generates a nationwide data product. It agglomerates the multivariate soil parameter space into a limited number of functional soil process units (SPUs) that facilitate operating agricultural process models. Each SPU is defined by a multivariate parameter distribution along its depth profile from 0 to 100 cm. It has a depth resolution of 1 cm and a spatial resolution of 100 m. The methodological approach is based on an unsupervised classification procedure involving remote sensing, cluster analysis, and machine learning. It accounts for differences in variable types and distributions and involves genetic algorithm optimization to identify those SPUs with the lowest internal variability and maximum inter-unit difference with regards to both, their soil characteristics and landscape setting. The high potential of the method is demonstrated for the agricultural soil landscape of Germany. It can be applied to other landscapes and ecosystem contexts.