bluuebunny/crossref_metadata_2025 huggingface dataset:
Evolution of brittle-ductile deformation to brittle fault zones and the role of fluid migration in Cruzeiro do Nordeste shear zone, Borborema Province, NE Brazil
Authors: Miranda Tiago , Barbosa Daniel , Correia Filho Osvaldo , Silva Acaua , Viegas Gustavo , Pacheco Sergio , Carvalho Bruno
Published: March 2024

The Borborema Province in northeastern Brazil is an ideal location for investigating the tectonic evolution of crustal-scale strike-slip shear zones. These structures exhibit an anastomosing network with numerous well-exposed mylonitic belts linked to the Neoproterozoic Brasiliano-Pan-African Orogeny. However, there is a gap in information on fluid-rock interaction related to both brittle-ductile and brittle deformation. This work aims to describe the control of brittle-ductile structures on the development of brittle fault zones with significant fluid interaction associated with the Cruzeiro do Nordeste shear zone, which limits the northern border of the Jatobá Basin. Our study is based on multiscale structural analyses, integrating aeromagnetic data, UAV images, outcrop-based measurements and microstructural characterization. We documented that the mylonitic foliation is represented by ENE-WSW magnetic positive anomalies (~14 nT/m) and is characterized by S-C fabrics indicating dextral kinematics. Brittle-ductile deformation is marked by dextral C'-type shear bands (WNW-ESE) and mesoscopic strike-slip faults (NW-SE and N-S). These structures exhibit bulges defined by fine-grained, peripheric quartz grains. C’ shear bands evolve into brittle fault zones composed of mosaic and chaotic breccias, veins filled by epidote, epidote+calcite, and calcite, which are associated with hydraulic brecciation. Cathodoluminescence analysis revealed variations in luminescence along the calcite-filled veins, suggesting at least two phases of fluid interaction. The older phase exhibits higher luminescence and is brecciated by the younger calcite fluid, which displays lower luminescence activation. This fluid-rock interaction can modify the permoporous system of analog reservoirs, which can be observed through the variation in cementation intensity in the Tacaratu Formation, sandstones of the Paleozoic sequence of the Jatobá Basin. Our results indicate that the Cruzeiro do Nordeste shear zone is an excellent example that preserves the record of ductile, brittle-ductile and brittle deformation due to exhumation. Furthermore, enhancing our knowledge of brittle deformation associated with the late stages of the Brasiliano-Pan-African cycle (Cambrian?) at shallow crustal levels may be the key to understanding the tectonic evolution of Paleozoic and Cretaceous sedimentary basins in northeastern Brazil. 
Linking midlatitude transient eddy moist static energy transport and extratropical cyclones
Authors: Zibell Jan , Schemm Sebastian , Hermoso Verger Alejandro
Published: March 2024

Earth's equator-to-pole net radiation gradient is counteracted by poleward atmospheric energy transport. In the extratropics, the largest contribution to this poleward flux can be attributed to variability on the timescale of weather systems. Even though the radiative imbalance has been argued not to strongly differ in a warmer climate, the partitioning of heat flux into moist and dry components is expected to change due to a moister atmosphere. On the synoptic scale, an increase in moisture and associated latent heat release enhances the intensification of cyclones, prolongs cyclone lifetimes, and also strengthens downstream anticyclones. Conversely, latent heating locally alters static stability and thereby affects projected trends in baroclinicity, which in turn vary across height due to different trends in temperature. Given that these drivers of cyclones and thereby storm tracks are subject to change and the resulting interplay is complex, isolating the influence of changes in latent heating on cyclone number and storm track intensity is not straight-forward. By combining the global moist static energy (MSE) budget perspective with cyclone numbers and other feature-based characteristics such as intensity and intensification, we aim to better understand the role of latent heat transport and release on midlatitude storm tracks. In particular, we ask: How are changes in zonal and time mean poleward transient eddy MSE flux and its divergence related to changes in cyclone number and intensities?We start investigating the linkage between MSE fluxes and surface cyclones in reanalysis data by calculating cyclone composites. These analyses reveal that in general, poleward flux in the vicinity of low-pressure systems reaches its maximum during the intensification phase and drops after cyclones reaching mature stage. Furthermore, MSE flux peaks slightly equatorward and downstream of the cyclone center. In the mean picture, this signal can be related to warm-sector flux along the cold front, also indicating that the footprint of cold-sector flux is not as dominant. Further separating dry and moist flux components is expected to reveal additional insight into how heat transport is distributed across cyclones. These diagnostics can readily be applied to climate model data and idealized aquaplanet simulations, which we make use of to reduce the complexity and single out the effect of individual drivers of storm track changes.
Can ambitious forestation mitigate temperature overshoot?
Authors: Moustakis Yiannis , Nützel Tobias , Wey Hao-Wei , Pongratz Julia
Published: March 2024

Even though it has been estimated that country-level commitments on Afforestation/Reforestation (AR) are quite ambitious, amounting globally to 633Mha by 2060, typically modelling studies either apply only moderate levels of AR or are fully idealized, thus not taking into account technoeconomic and biodiversity considerations. Typically, high-end emission trajectories are also employed, yielding strong fertilization of vegetation by elevated CO2 levels and thus enhanced terrestrial carbon stocks, while the CDR potentials over more strongly mitigated pathways remain understudied. This is especially the case for overshoot pathways that are gaining research interest recently, given their relevance for reaching the more ambitious 1.5oC goal.Here, with the fully coupled MPI-Earth System Model we investigate the mitigation potential of an ambitious yet spatiotemporally plausible AR scenario under an overshoot emission trajectory (SSP5-3.4os). The developed AR scenario employed here is commensurate with country commitments in 2060 and extends to 2100 reaching 935 Mha globally and is constrained by technoeconomic considerations based on a multitude of 1,259 Integrated Assessment Model-generated pathways. To further constrain the scenario, we consider biodiversity and restoration priority maps.Based on a big ensemble member approach allowing for robust probabilistic analysis, our results demonstrate that ambitious AR can robustly mitigate global temperature in 2100 by 0.2oC, peak temperature by 0.09oC, and reduce temperature overshoot duration by 13 years, while also delaying the land carbon sink-to-source transition by ~10 years, compared to a reference scenario with constant land-use at 2015 levels. Temperature mitigation emerges also at the local scale, where biogeochemically-induced cooling compensates for any biogeophysically-induced local warming.Overall, ambitious AR should be considered as a useful mitigation tool complementary to drastic emissions reduction even under more strongly mitigated pathways, despite potentially weaker CO2 fertilization.
Actinidia chinensis: physiological and productive performances under different irrigation restitutions
Authors: Boini Alexandra , Bortolotti Gianmarco , Perulli Giulio Demetrio , Corelli Grappadelli Luca , Manfrini Luigi
Published: March 2024

Yellow flesh kiwi fruit production normally follows protocols based on the green species, A. deliciosa, often resulting in low yields, attributable to small sized fruit, meaning A. chinensis seems more susceptible to water limitations. Understanding the species physiology and fruit vascular flows may help determine this crop’s evapotranspiration needs, to efficiently obtain satisfactory harvests. The presented work results from a 3-year trial (2019-2020-2021), where control irrigation vines were compared with deficit-irrigated and over-irrigated vines. Midday physiology, including plant water relations, leaf gas exchanges and fruit vascular flows were analysed, along with harvest parameters and dry matter content. Irrigation treatments influenced the vines’ responses only when soil water content was below certain levels, reflecting sensitivity of the crop to water changes in the soil. Although no significant differences were found in harvest parameters, dry matter content was higher for the less irrigated fruit. The less irrigated treatment performed less better, than the control and the over-irrigated, especially when water supply did not fulfil fruit transpiration. This occurred during the berry development phase (around 1 month after full bloom), a critical period during which the fruit has very high transpiration rates, which passively call photosynthates (phloem inflow) to provide energy for cell division. Fruit transpiration appears to influence phloem inflow during most of the season, even until 1 month before harvest, however the initial phases of fruit development and growth are pivotal for final yield. Vascular flows allowed to unveil a typical simplasmic behaviour in the early stages of berry development, meaning the microenvironment is intensely influencing fruit behaviour. Irrigation must respond to the needs of young fruit, taking into account soil water content and the phenological phase. The use of sensors, plant based and environmental, is an important technique for determining the necessary water volumes for yellow kiwi fruit.
Assessing the influence of large wood on sediment connectivity and river morphology in small streams in the Vienna Woods (Austria)
Authors: Diem Sarah , Chmela Stefanie , Pöppl Ronald
Published: March 2024

Depending on their geometry, in-stream large wood (LW) pieces can significantly influence the morphology and hydraulic properties, the water and sediment connectivity of river channels as well as the riverine biodiversity. Such depositions often form hydraulic resistance, change the flow velocity and reduce the transport capacity. This, in turn, might affect the water and sediment connectivity of a channel, resulting in increased sediment deposition. Furthermore, LW can form new morphological structures, such as riffles or pools or alter already existing ones, for example river banks. The deposition of LW in streams is also associated with positive effects on biodiversity, as changes in the channel and flow patterns can significantly improve the heterogeneity of habitats.In Europe, a lack of studies related to in-stream wood and its effects on channel morphology and sediment connectivity exists, as most research on this topic has been conducted in North America. In addition, the predominantly applied methodology is very time-consuming and complex, as the influence of LW is mostly based on the determination of drag force. The aim of this study is therefore, to apply a simple method to investigate the influence of LW on water and sediment connectivity in small streams in the Vienna Woods (Austria). Furthermore, geomorphological mapping is used to asses the effects of LW on channel morphology.The study has been conducted in four mid-mountain streams of the Vienna Woods, located in the vicinity of the city of Vienna (Austria). LW deposits and potential sediment sources are mapped, classified and counted according to predefined criteria. Sediment deposits are measured and visible morphological changes, both associated with LW, are documented. The collected data is then used to (1) create a map, indicating LW accumulations in the research area; (2) determine the amount of retained material; and (3) apply the recently introduced indices IDLW (LW disconnectivity index) and RPLW (LW sediment retention potential index) (Pöppl et al., 2024) to gain an overview over the disconnectivity and sediment retention potential the LW deposits exhibit.First results of this study will be presented at the EGU General Assembly 2024. Reference: Pöppl, R.E., Perez, J., Fergg, H., Morche, D. (2024) Introducing indices to assess the effects of in-stream large wood on water and sediment connectivity in small streams. Geomorphology 444, 10893
Unveiling the Sustainability Quotient: Blue and Green Evapotranspiration Dynamics Analysis in the Upper Cauvery Basin
Authors: Vasala Saicharan , Hassan Rangaswamy Shwetha
Published: March 2024

Efficient management of water resources is imperative for sustainable development, necessitating a meticulous partitioning of evapotranspiration into blue and green components. Our study focuses on the Upper Cauvery region, examining water utilization from both rainfed and irrigated sources. Modifying the Hoekstra framework in the context of employing geospatial data and machine learning techniques, we partitioned water resources into blue (ETb) and green (ETg) evapotranspiration, unravelling valuable insights. Results from the decade-long analysis (2010-2020) reveal that ETb significantly outweighs ETg in this region. Examining the temporal trends, both ETb and ETg exhibit a consistent upward trajectory over the specified period, illustrating the evolving water consumption dynamics from 2010 to 2020. The implications of our study extend to potential applications in sustainable water resource utilization and management practices, providing a valuable contribution to the scientific community and policymakers alike. The findings will also raise awareness about the importance of using water resources responsibly in this vital geographical area.
Earlier flowering onset induced by air heating occurs only in certain grassland species in the Giessen T-FACE experiment
Authors: Dehn Philipp , Grüters Uwe , Moser Gerald , Müller Christoph
Published: March 2024

This study investigates the flowering onset of species in an extensively managed, temperate grassland under future atmospheric conditions. Free air CO2 enrichment experiments combined with a warming treatment via IR heaters (T-FACE) are state of the art for investigating future developments in terrestrial ecosystems. This study presents the first results of a new approach to T-FACE technology. In this experiment, the air temperature is increased directly via heating elements, thus creating more realistic environmental conditions for future climate studies.Plant phenology, a widely used indicator of changing environmental conditions, was therefore one of the first subjects to be investigated with the new system. Four grasses and five herbaceous plants were monitored several times a week for the onset of flowering over a period of five years.These were Arrhenatherum elatius, Holcus lanatus, Poa pratensis, Trisetum flavescens as well as Draba verna, Galium album, Geranium pratense, Glechoma hederacea and Sanguisorba officinalis.While significantly earlier flowering was observed in some species, other species showed no change in the onset of flowering. Results suggest that changes in the onset of flowering were mainly seasonal and independent of the functional plant group.
Liming effects on microbial carbon use efficiency and its potential consequences for soil organic carbon stocks
Authors: Schroeder Julia , Damatirca Claudia , Bölscher Tobias , Chenu Claire , Elsgaard Lars , Tebbe Christoph C. , Skadell Laura , Poeplau Christopher
Published: March 2024

The allocation of metabolised carbon (C) between soil microbial growth and respiration, i.e. C use efficiency (CUE) is crucial for SOC dynamics. The pH was shown to be a major driver of microbial CUE in agricultural soils and therefore, management practices to control soil pH, such as liming, could serve as a tool to modify microbial physiology. We hypothesised that raising soil pH would alleviate CUE-limiting conditions and that liming could thus increase CUE, thereby supporting SOC accrual. This study investigated whether CUE can be manipulated by liming and how this might contribute to SOC stock changes. The effects of liming on CUE, microbial biomass C, abundance of microbial domains, SOC stocks and OC inputs were assessed for soils from three European long-term field experiments. Field control soils were additionally limed in the laboratory to assess immediate effects, accounting for lime-derived CO2 emissions (δ13C signature). The shift in soil pHH2O from 4.5 to 7.3 with long-term liming reduced CUE by 40%, whereas the shift from 5.5 to 8.6 and from 6.5 to 7.8 was associated with increases in CUE by 16% and 24%, respectively. The overall relationship between CUE and soil pH followed a U-shaped (i.e. quadratic) curve, implying that in agricultural soils CUE may be lowest at pHH2O = 6.4. The immediate CUE response to liming followed the same trends. Interestingly, liming increased microbial biomass C in all cases. Changes in CUE with long-term liming contributed to the net effect of liming on SOC stocks. Our study confirms the value of liming as a management practice for climate-smart agriculture, but demonstrates that it remains difficult to predict the impact on SOC stocks due its complex effects on the C cycle.
Unraveling the relationship between rural farm household wealth, carbon storage, and soil quality in Namibia's Zambezi Region
Authors: Dr. Sandhage-Hofmann Alexandra , Mira Foerster , Vanessa Amatotsero , Jan Börner , Bisrat Gebrekidan , Wulf Amelung
Published: March 2024

A significant portion of smallholder farming systems in Sub-Saharan Africa are marked by significant heterogeneity in both biophysical and socio-economic conditions. Resource access and the patterns of resource allocation at household level are often co-determined by wealth. We hypothesized that wealth plays a pivotal role in the effect of future-oriented farm management on soil organic carbon storage (SOC) and soil quality. To test this hypothesis, we conducted a study involving 42 households categorized in three wealth classes (high, medium, low) based on farm-household survey data from the Namibian Zambezi region. Soil samples were collected up to a depth of 1 m with a focus on soil organic carbon and nitrogen throughout the soil profile. Topsoils were additionally analyzed for texture, cation exchange capacity (CEC), pH, and available phosphorus; field size was measured. A follow-up survey wave captured information on crop species, yield, and soil management practices.Results of the survey showed, that farmers of our study area typically burn their field regularly before the cultivation period. With rare exceptions no farmer fertilized their fields, neither with mineral fertilizer nor with manure. Results indicated that relatively wealthier farmers had larger fields, yet intriguingly, their yields per hectare were not higher than for farmers in lower wealth terciles. Notably, the Arenosols, which are widespread in the Zambezi region, had lower sand and higher clay and silt contents among the relatively wealthier farmers. Moreover, high wealth class showed significantly higher soil organic carbon and nitrogen concentrations in the topsoils compared to medium and low wealth classes along with CEC values. Though, no such a trend was observed for available phosphorous and pH. The elevated levels of soil organic carbon and nitrogen of relatively wealthy farmers persisted consistently up to a depth of 1 meter. These results indicate that the soils of farmers in the high wealth class have inherently better soil conditions. Contrary to our hypothesis, the wealthier farmers did not seem to invest more in land management in order to improve soil conditions. Instead, historically they seem to have been more inclined to settle on the more fertile soils in the Zambezi region of Namibia and benefit from larger fields and thus higher quality natural resources.
Enhancing Hydrological Predictions: Feature-Driven Streamflow Forecasting with Sparse Autoencoder-based Long Short-Term Memory Networks
Authors: Vinod Neha , Geetha Raveendran Arathy Nair , Sankaran Adarsh , Kochukattil Ajith Anandu
Published: March 2024

In response to the critical demand for accurate streamflow predictions in hydrology, this study introduces a Sparse Autoencoder-based Long Short-Term Memory (SA-LSTM) framework applied to daily streamflow data from three-gauge stations within the Greater Pamba River Basin of Kerala, India, which was the worst affected region by the devastating floods of 2018. The SA-LSTM model addresses the challenge of feature selection from an extensive set of corresponding 1 to 7 days lagged climatic variables, such as precipitation, maximum and minimum temperatures, by incorporating a sparsity constraint. This constraint strategically guides the autoencoder to focus on the most influential features for the prediction analysis. The prediction process involves training the SA-LSTM model on historical streamflow data and climatic variables, allowing the model to learn intricate patterns and relationships. Furthermore, this study includes a comparative analysis featuring the Random Forest (RF)-LSTM model, where the RF model is employed for feature extraction, and a separate LSTM model is used for streamflow prediction. While the RF-LSTM combination demonstrates competitive performance, it is noteworthy that the SA-LSTM model consistently outperforms in terms of predictive accuracy. Rigorous evaluation metrics, including Correlation Coefficient (R2), Root Mean Square Error (RMSE), Mean Square Error (MSE), and Mean Absolute Error (MAE), highlight the SA-LSTM's forecasting accuracy across the three stations. Notably, the R2 values surpass 0.85, RMSE values remain under 12 cubic meters per second (m³/s), MSE values are below 70 (m³/s), and MAE values approach 8 m³/s. The detailed comparison between the above models underscores the superior capabilities of the SA-LSTM framework in capturing complex temporal patterns, emphasizing its potential for advancing hydrological modeling and flood risk management in flood-prone regions. Key words : Streamflow, LSTM, Sparse Autoencoder, Flood, Greater Pamba
Long-term denudation and topographic relief evolution of Central and Northern Madagascar
Authors: Clementucci Romano , Willett Sean , Wang Yanyan , Datian Wu , Haghipour Negar , Randriamananjara Hervé , Ranaivoson Nirina Tedy
Published: March 2024

The landscape of Central and Northern Madagascar is characterized by residual landforms, steep slopes, and low-relief areas, resulting mainly from the processes of dissection of the central high plateau and retreat of two main topographic scarps on the western and eastern margins of the island. On the western side, the topography is characterized by relict relief and a highly sinuous plateau edge. Conversely, the landscape on the eastern side is dominated by the great topographic escarpment with a linear plateau edge. Locally, this general morphology is perturbed by the formation of the active Alaotra-Ankay rift system, which displaces the plateau-escarpment system. Here, we explore the long-term relief evolution of these three morpho-structural domains (west and east sides and rift sector) by combining denudation rates derived from cosmogenic nuclides and geomorphic stream profile analysis. Our results show that, although the erosional dynamics are dominated by the same processes of plateau dissection and scarp retreat, the topographic features, drainage networks, and distributions of species richness differ within these three domains. We provide insight into the processes that lead to transient landscape and relief evolution of rifted margins.
Deep Embedded Clustering of a Cryo-Data-Cube
Authors: Peters Julia , Roth Felix , Umaluft Josefine
Published: March 2024

Cryoseismological records consist of numerous signals generated by various sources within or surrounding glacial ice, including icequakes, water flow, avalanches, rockfalls, wind, or precipitation. This results in a notably high noise level within the data, posing a significant challenge in detecting and distinguishing individual seismic events and sources.Our research employs Deep Embedded Clustering (DEC) to address this challenge, focusing on the analysis of a Distributed Acoustic Sensing (DAS) dataset acquired on Rhonegletscher (Switzerland) in 2020.To visualize and efficiently streamline the DEC processing of this substantial volume of data, we reorganize the numerous continuous DAS channels as a 3D data cube featuring the three dimensions: time, space, and frequency. The DEC approach involves first transforming high-dimensional seismic data into a more manageable lower-dimensional latent space using an autoencoder. This transformation is vital in emphasizing the essential characteristics of the data, thereby enabling more effective clustering. Subsequently, the DEC algorithm autonomously categorizes these seismic signals into distinct clusters based on their unique spatio-temporal characteristics, without the prerequisite of manual annotation.The primary aim of this approach is to utilize DEC for the effective mapping of clearly defined spatio-temporal clusters within cryoseismological records. This approach is geared towards achieving a more nuanced understanding of the various sources contributing to these records and their complex dynamics. By successfully segregating these clusters, the aim is to reveal new insights into the complex processes and interactions in glacial environments.Both the DAS data and the clustering results can be explored interactively using the data cube viewer Lexcube. Come find us at the poster stand!
Glaciers – an overlooked water balance component in global hydrological modeling
Authors: Hanus Sarah , Schuster Lilian , Burek Peter , Maussion Fabien , Wada Yoshihide , Viviroli Daniel
Published: March 2024

Although the share of glacier coverage is generally limited in large river basins, glaciers act as large water storages and contribute to runoff in the summer months. Due to climate change, glacier runoff is undergoing considerable change and is expected to decrease significantly by the end of the century. Thus, glaciers are a water balance component with a strong seasonal pattern which is rapidly changing in the future. However, glaciers have been mostly omitted in large-scale hydrological models so far, which limits climate impact studies on global water resources.We aimed to improve the glacier representation in regional and global hydrological modelling and assess the contribution of glaciers to runoff. Therefore, we sequentially coupled the global glacier model OGGM (Maussion et al., 2019) with the large-scale hydrological model CWatM (Burek et al., 2020).Coupling a glacier model with a hydrological model for global application comes with multiple challenges, such as precipitation data adjustment, different spatial and temporal resolutions, different snow process representations and model calibration. Here we elaborate on our experience of combining glacier and hydrological modelling, its challenges and uncertainties.Moreover, we show results of glacier contributions to runoff in the past and under future scenarios. Glacier contributions to runoff are largest close to the glaciers and decrease downstream. Nevertheless, the runoff contribution from glaciers at the outlet of large river basins often remains important, especially in dry periods. We analyzed projected changes in glacier contribution to discharge at the outlet of 56 glacierized river basins globally. Our analysis suggests that the relative glacier contributions to discharge will decrease drastically towards the end of the century, also under the low-emission scenario SSP1-2.6.Thus, including glaciers in regional and global assessments of water availability is especially relevant when assessing future changes, particularly on seasonal or shorter timescales. Otherwise, future changes in discharge are likely underestimated in glacierized basins.The hydrological and glacier modelling communities should foster continued collaborations to include glaciers in the modelling of the water cycle and address the associated challenges.Burek, P., Satoh, Y., Kahil, T., Tang, T., Greve, P., Smilovic, M., Guillaumot, L., Zhao, F., and Wada, Y.: Development of the Community Water Model (CWatM v1.04) – a high-resolution hydrological model for global and regional assessment of integrated water resources management, Geosci. Model Dev., 13, 3267–3298, https://doi.org/10.5194/gmd-13-3267-2020, 2020.Maussion, F., Butenko, A., Champollion, N., Dusch, M., Eis, J., Fourteau, K. et al..: The Open Global Glacier Model (OGGM) v1.1, Geosci. Model Dev., 12, 909–931, https://doi.org/10.5194/gmd-12-909-2019, 2019.
Vertical distribution of net zooplankton biomass at the time of winter vertical mixing in the open southern Adriatic Sea (Mediterranean Sea)
Authors: Batistić Mirna , Garić Rade , Hure Marijana , Pasković Nika , Ursella Laura , Cardin Vanessa , Civitarese Giussepe , Gačić Miroslav , Miserocchi Stefano
Published: March 2024

The open southern Adriatic Sea with a maximum depth of 1242 m is one of the three sites of open deep-sea convection in the Mediterranean Sea. The effects of winter vertical mixing on zooplankton biomass were investigated in the open southern Adriatic Sea in February 2023. Samples were collected using Nansen nets (250 µm mesh size) in eight layers from 0 to 1200 m depth during day and night. The highest biomass values were sampled in the deeper layers below 300 m depth (twice as high as in the upper layers) both in the day and night samples. This could be related to vertical mixing in several pathways. This event was triggered by cold winter conditions and significant heat loss in the previous days, which together with the inflow of high salinity water from the eastern Mediterranean (38.96) caused strong vertical mixing down to 600 m depth. As a result of this event, relatively high chlorophyll-a concentrations (max. 0.33 mgm-3) were measured down to 600 m depth. Therefore, due to the vertical mixing, deeper layers received more food than usual from the surface, so that more food was available for deep-sea zooplankton organisms and they did not have to migrate upwards. The effect of vertical mixing in winter was also clearly visible in some zooplankton organisms that cannot effectively resist the vertical currents, so that they also contribute to the increase in biomass at depth. This is confirmed by the backscattering strength (Sv) data, which show that convective mixing resulted in a smeared Sv signal, indicating that the plankton was transported to deeper layers and no migration took place.Future studies should consider the influence of open-sea convective events on vertical carbon export in the oligotrophic southern Adriatic. 
Impact of marine gateways on oceanic circulation and carbon cycle in the Late Eocene
Authors: Fabre Emma , Ladant Jean-Baptiste , Donnadieu Yannick , Sepulchre Pierre
Published: March 2024

The Late Eocene is a period of global cooling and high-latitude tectonic changes culminating in the Eocene Oligocene Transition (34 Ma ago), one of the major climatic shifts of the Cenozoic. Across the Late Eocene, the Earth went from a largely ice-free greenhouse during the early Eocene climatic optimum to an icehouse with the ice sheet inception over Antarctica. This long-term cooling happened simultaneously with a decrease in the atmospheric content in carbon dioxide whose causes are still unclear.During the same period, marine gateways surrounding Antarctica (Drake Passage and Tasman Gateway) opened and deepened and Atlantic-Artic gateways changed configurations, thereby allowing the onset of oceanic currents such as the circumpolar current isolating Antarctica.Here, we investigate how coupled changes in the configuration of these gateways may impact oceanic circulation and carbon cycle using climate simulations performed with the IPSL-CM5A2 model, an Earth System Model equipped with the biogeochemical model PISCES. Our reference simulation uses the paleogeography from Poblete et al (2021), based on the paleobathymetry of Straume et al (2020). Several sensitivity experiments with different gateway configurations are then presented and discussed, with specific focus on global ocean circulation changes and implications for the carbon cycle.
Evaluation of MERRA-2 reanalysis for Sulfur dioxide aerosol in China
Authors: Shaheen Abdallah , Yousefi Robabeh , Wang Fang , Ge Quansheng , Wu Renguang
Published: March 2024

Considering the uncertainty of the reanalysis data is essential, the uncertainty of Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2) SO2 concentration still is lacking. In this talk, we evaluated the MERRA-2 SO2 concentrations in China. Monthly SO2 concentrations from 100 ground observation during the years 2015-2021 were used to evaluate the monthly MERRA-2 SO2 data. Our results showed that the MERRA-2 SO2 concentrations exhibit a moderate Pearson correlation coefficient (R) with ground-based SO2 measurements (R = 0.62). In terms of root-mean square error (RMSE) and mean absolute error (MAE), biases (≤ 10 μg m-3) were found mainly for extensive regions (about 70%) of the Chinese sites. According to the results, the relative mean bias (RMB) and fractional gross error (FGE) showed values greater than 1 and 0, respectively, in the eastern China, which indicates that MERRA-2 overestimates the SO2 measurements in the urban regions, while underestimation of MERRA-2 SO2 was found in rural regions of China. A parameterized method could be suggested to improve the quality of MERRA-2 SO2
Assessing and mapping of land subsidence risk at different scales in major urban areas in Italy 
Authors: Bonì Roberta , Cigna Francesca , Teatini Pietro , Paranunzio Roberta , Zoccarato Claudia
Published: March 2024

High to very high susceptibility and hazard levels of land subsidence have been identified in several Italian regions: Emilia-Romagna and Veneto regions, where loss of land elevation up to 7 cm/year in the Po River Plain impacts 30% of the Italian population since the 1950s; Puglia, e.g. at Tavoliere Plain, with land subsidence up to 2 cm/year; the Florence-Prato-Pistoia Plain in Tuscany and the Volturno Plain in Campania, with more 2 cm/year; the Gioia Tauro Plain in Calabria with more than 1 cm/year.Assessing the contribution of urbanization and the growth in urban population to this process is still a challenging task.The SubRISK+ project is aimed to provide new Earth observation-derived products and tools to improve the comprehension of current and future land subsidence in major urbanized areas of Italy. The project is funded by the European Union – Next Generation EU, in the framework of the Research Projects of Significant National Interest (PRIN) - National Recovery and Resilience Plan (PNRR) call 2022, and it is led by the National Research Council of Italy in Rome with the collaboration of the University School for Advanced Studies of Pavia and the University of Padua.In particular, the risk associated to land subsidence will be investigated for the 15 metropolitan cities of Italy and the Emilia Romagna region by exploiting Copernicus’ European Ground Motion Service (EGMS) data.Satellite-based Interferometric Synthetic Aperture Radar (InSAR) observations will be employed to map the current land subsidence and assess the potential induced damages to urban infrastructures.Then, a multidisciplinary approach incorporating geological, hydrogeological, geotechnical, land use data, and ground displacement observations will be implemented to disentangle the contribution of various processes and evaluate the associated triggers.The activities will be performed across national, regional, and local scales. The use of advanced groundwater flow and geomechanics model for a “hotspot city” case study will allow to quantify the effects of groundwater exploitation and estimate uncertainties in land subsidence.Market and non-market direct/indirect losses will be assessed at national, regional, and local scales via a newly developed socio-economic impact analysis, based on the exposure, vulnerability, and resilience of the investigated urbanized areas. Finally, future land subsidence risk scenarios will be estimated in the medium (2050) and long term (2100).
ITRF2020 Updates : motivation and expectation
Authors: Altamimi Zuheir , Rebischung Paul , Collilieux Xavier , Métivier Laurent , Chanard Kristel
Published: March 2024

The ITRF2020 marked considerable innovations compared with previous versions of the ITRF, by modeling nonlinear station motions (seasonal signals and Post-Seismic Deformation –PSD– for sites subject to major earthquakes). It also confirmed the stability of the CM-based frame origin, as sensed by SLR, at the level of or better than 5 mm and 0.5 mm/yr. For the first time in the ITRF history, the scale agreement between SLR and VLBI solutions submitted to ITRF2020 is at the level of 0.15 ppb (1 mm at the equator) at epoch 2015.0, with no drift. Motivated by these results, and for a number of reasons that will be exposed in this paper, the ITRS Center decided to regularly (yearly) update the ITRF2020, with a first update expected to be released around mid-2024. Depending on the input data availability that will be submitted by the four technique services, we expect some preliminary results that will be discussed in this presentation. Emphasis will be given to answer some critical questions, such as: how does the VLBI scale drift evolve after 2021.0? Do the SLR and VLBI scales remain in agreement? Does the SLR origin drift or not from the ITRF2020 origin after 2021.0?
4000 Sols on Mars - A Long-term Study of Radiation Variations
Authors: Löwe Jan Leo , Wimmer-Schweingruber Robert , Khaksarighiri Salman , Hassler Donald , Guo Jingnan , Ehresmann Bent , Zeitlin Cary , Matthiä Daniel , Berger Thomas , Reitz Günther , Löffler Sven
Published: March 2024

The Radiation Assessment Detector (RAD) onboard the Mars Science Laboratory's Curiosity rover is the first-ever instrument continuously monitoring energetic particles on the surface of Mars. Since the rover's landing on August 6, 2012, RAD has accumulated valuable data, providing an unprecedented opportunity to assess the radiation environment across a solar cycle on an another planet.Understanding the radiation environment on Mars is crucial for a more accurate assessment of the risks posed to manned future space missions. Moreover, it also serves to further investigate planetary conditions, properties of the Sun, and galactic cosmic rays (GCRs).  The radiation field on the surface of Mars primarily consists of charged particles, including primary GCRs propagating to the Martian surface and secondary particles generated through the interaction of primary GCRs with the Martian atmosphere or soil. Furthermore, it undergoes temporal changes caused by factors such as atmospheric pressure variations due to thermal tides, seasonal changes, geographical and topographical shielding effects, heliospheric modulation of GCRs, as well as Martian soil and subsurface conditions. Considering all these factors is essential for a comprehensive description of the radiation environment.  Here we utilize the extensive RAD dataset spanning the last 11 years to delve into the intricate variations in particle flux. Our analysis encompasses a diverse array of particle species, providing a comprehensive understanding of how particle flux evolves over the course of one complete solar cycle. This extended time frame allows us to capture and analyze long-term trends, offering valuable insights into the dynamic nature of particle interactions within the Martian environment. By exploring the temporal patterns of particle flux across different species, we aim to contribute to a more nuanced comprehension of the complex radiation dynamics on Mars and its implications for future space missions and potential habitation.  Additionally, we endeavored to understand the impacts of subsurface composition on the Martian surface radiation field, particularly in generating additional upward particles. This investigation is significant as it contributes to the exploration of potential subsurface water content on the surface of Mars.
Mapping and characterizing peatland using ground-penetrating-radar and nuclear-magnetic-resonance
Authors: Müller-Petke Mike , Blanco Arrué Bárbara , Igel Jan , Splith Tobias , Costabel Stephan
Published: March 2024

Peatlands are of importance for a number of environmental services and ecological processes. They are a crucial component of the global carbon cycle and, therefore, of special interest in times of climate change. On the one hand, drained peatlands irreversibly degenerate when used for agriculture and lose their physicochemical functionality. On the other hand, activities on renaturation or joint use are in discussion or already in practice. Consequently, there is a demand for knowledge of the state of the peat layers and for the ability to monitor their changes, most preferably in high detail and on a large scale. Airborne geophysics and remote sensing (e.g. optical images, radar or electromagnetics) are  approaches to gain large-scale information on the lateral extend of peatlands, however, covering the large scale comes along with limitations and uncertainties on knowledge about thickness, internal structure, or degradation states.We conducted a ground-penetrating-radar (GPR) and nuclear-magnetic-resonance (NMR) survey at a peatland site in northern Germany, which has been in agricultural use for decades. The site is characterized by a peat layer of varying thicknesses between 0--4 m covering mineral sediments. While GPR provides a fast 3D insight into the internal structure, extent, and thickness, NMR enables the characterization of the internal layers detected by GPR in more detail and may provide information on their degradation states. The results are compared to visually inspected vertical soil sampling data. Our study demonstrates that ground-based geophysics can provide the demanded detailed information and may easily be upscaled to effectively cover areas at the kilometre scale.
A fusion retrieval approach for monitoring upstream suspended sediment fluctuations using Sentinel-2 imagery
Authors: Cao bowen , Picco Lorenzo , Yang Xiankun
Published: March 2024

Remote sense data are increasingly being developed also to accomplish environmental monitoring activities. In the context of climate change, a growing number of extreme events are being observed worldwide, leading to significant changes in surface hydrological processes. This shift is a crucial factor in the alteration of suspended sediment concentration (SSC) in large rivers. Particularly, large rivers originating in the high mountainous regions of Asia and flowing into densely populated areas of Southeast Asia are more susceptible to erosion due to their geomorphic characteristics and intensive human activities. Faced with grand and complex geomorphic conditions, there is a need to adopt a basin-wide perspective by employing a broader array of monitoring methods. This is particularly important for the Pearl River, a major river in southern China. Retrieval of SSC using remote sensing is one of the popular monitoring methods in the past decades. Unfortunately, its application has mainly focused on the estuary and coastal open water. In this study, we place a stronger emphasis on the basin-wide scale, specifically focusing on the upstream and major tributaries. We recalibrated model parameters using a general index model (Gindex) and a regional high-precision model (CSSC). These recalibration results were combined with Sentinel-2 imagery and field data to establish a basin-wide suspended sediment monitoring program. The results of the integrated model fit (n = 29), R2 = 0.95, RMSE = 14.15 mg/L. The modeling results indicated that the spatial distribution of SSC in the upstream and tributaries of the Pearl River showed a clear concentration pattern, with markedly different concentrations in the upstream and downstream reaches. In the upstream, the SSC distribution was clearly divided into two parts, with concentrations of 104.85 mg/L and 13.43 mg/L, respectively, reflecting a substantial difference. It is worth noting that the monthly SSC statistics were clearly seasonal related to the precipitation. May and June were two months with high SSC concentrations in the whole river, with median values of 85.51 mg/L and 106.48 mg/L, respectively. In addition, we observed an abrupt change in suspended sediment downstream of the large reservoirs. This difference is likely caused by the streamflow resulting from the high drop of the dam or channel narrowing. Consequently, we have analyzed the suspended sediment dynamics of both the mainstem and major tributaries of the entire Pearl River. The results will enhance the understanding of suspended sediment changing in large rivers, serving as a valuable complement to water resource management and soil erosion risk assessment.
Competing development of S and C foliations in mylonites
Authors: Chatterjee Pramit , Roy Arnab , Mandal Nibir
Published: March 2024

Mylonites are characteristic rocks in ductile shear zones, and they contain two primary fabrics: i) C-fabrics, which are usually aligned parallel to the principal shear planes in the shear zones, ii) S-Foliations, which are oriented at angles to the shear plane, showing their vergence in the shear direction. Despite extensive studies of mylonite structures over several decades, the factors controlling the formation of S and C fabrics and their relative abundance in ductile shear zones are yet to be fully explored. This article investigates the competing development of S and C fabrics in ductile shear zones from two geological terrains of Eastern India. The shear zones offer macroscopic observations of various mylonitic rocks: i) C mylonites ii) S mylonites, and and iii) S-C mylonites.  Numerical simulations were performed to replicate them in model shear zones, considering a combination of transient visco-plastic rheology. The model study suggests that the growth of C- versus S- fabrics in mylonites depend on two fundamental non-dimensional parameters: imposed strain rate and bulk viscosity. It is observed that low bulk viscosity and strain rate conditions promoted the formation of S fabrics. With increase in bulk viscosity and strain rate, formation of C bands in the shear zones is facilitated leading to the localisation of strain in the form of narrow zones.