bluuebunny/crossref_metadata_2025 huggingface dataset:
Using simulated grassland communities and radiative transfer models to test the Spectral Variation Hypothesis
Authors: Ludwig Antonia , Doktor Daniel , Feilhauer Hannes
Published: February 2023

Increasing land use and climatic change lead to a global decline of biodiversity at alarming rates. To counteract this massive loss, global aims such as the convention of biological diversity’s Aichi targets and related conservation programs have been launched. These programs require a detailed monitoring of biodiversity across large areas, which raises high expectation with respect to biodiversity assessments from Earth Observation data. One frequently discussed approach is an application of the so called Spectral Variation Hypothesis (SVH). This approach aims to link the spectral variation of remotely-sensed image data to environmental heterogeneity as the main driver of species diversity in a given area. According to the SVH, diversity in leaf and canopy optical properties and habitat structures increase with increasing species diversity what in turn drives variations in the spectral signature of the plant communities. Various studies that explore these correlations in terrestrial ecosystems come to promising conclusions. However, the transferability of the proposed relations between spectral and taxonomic diversity to other ecosystem types and across different spatial resolutions remains unclear. Especially for grasslands where the mismatch between pixel and individual plant size is heavily pronounced, no comprehensive study has systematically tested the SVH yet. To fill this gap, we developed a theoretical framework that enables the simulation of realistic reflectance patterns of grassland vegetation. Thereby, we can mimic the spectral signal hypothetically reaching different sensor systems. Moreover, it allows us to test the relationships between spectral variation and taxonomic diversity for a high number of simulated plant communities. We created spatial distributions of artificial grassland units based on species inventories and trait data that we sampled in the field. We further simulated the spectral signature of these artificial communities using the leaf and canopy RTM PROSAIL. By including in-situ plant traits (species-, site- and season-specific, sampled on the individual plant level) we 1) simulate realistic reflection profiles which also incorporate seasonal dynamics, 2) modify species composition and species richness, and 3) use this as the basis to assess scaling effects. The modelling framework will be presented as well as the results of the spatial plant community simulations including the generated spectral patterns for three sites and seasons. Further, first results regarding the spectral-to-taxonomic diversity relationship will be discussed. 
From research to the operation of solar wind forecasting with SafeSpace Helio1D: lessons learned and ways forward
Authors: Kieokaew Rungployphan , Pinto Rui , Indurain Mikel , Samara Evangelia , Lavraud Benoit , Brunet Antoine , Poedts Stefaan , Génot Vincent , Rouillard Alexis , Bourdarie Sébastien , Daglis Ioannis
Published: February 2023

Our current capability of space weather prediction in the Earth's radiation belts is limited to only an hour in advance using solar wind monitoring at the Lagrangian L1 point. To mitigate the impacts of space weather on telecommunication satellites, advancing the lead time of the prediction is a critical task. We develop a prototype pipeline called "Helio1D" to forecast ambient solar wind conditions (speed, density, temperature, tangential magnetic field) at L1 with a lead time of 4 days. This pipeline predicts Corotating Interaction Regions (CIRs) in which their compressed stream interfaces and high-speed streams can increase high-energy fluxes in the radiation belts. The Helio1D pipeline connects the Multi-VP model, which provides real-time solar wind emergence at 0.14 AU, and the 1D MHD model. Using the long-term data from Multi-VP, we benchmark the Helio1D pipeline for solar wind speed against the observation data in 2004 - 2013 and 2017 - 2018. We developed a framework based on the Fast Dynamic Time Warping technique that allows us to continuously compare time-series outputs containing CIRs to observations to measure the pipeline's performance. In particular, we use this framework to calibrate and improve the pipeline's performance for operational forecasting. Since the 1D MHD model is computationally inexpensive, we provide daily ensemble forecasting of 21 members, including several targets around the Earth to account for the uncertainties. This pipeline can be used to feed real-time, daily solar wind forecasting to predict the dynamics of the inner magnetosphere and the radiation belts. In this presentation, we will share the lessons from this research-to-operation project and discuss ways to effectively implement operational space weather pipelines.  
Late Cenozoic oxygenation of the Pacific Ocean, a perspective from planktic foraminiferal I/Ca
Authors: Nilsson-Kerr Katrina , Hoogakker Babette , Reyes Macaya Dharma Andrea , Winkelbauer Helge Arne
Published: February 2023

The Pacific Ocean hosts one of the most extensive areas of oxygen deficient waters at present with well-defined areas of oxygen minima existing both north and south of the equator along the eastern basin. This deficiency in oceanic O2 concentrations is mainly due to a combination of upwelling induced high primary productivity and poorly ventilated intermediate waters. Across the Miocene-Pliocene the Pacific Ocean is thought to have been distinctly different with an elevated water column temperature profile, reduced Walker circulation, active deep-water formation in the north Pacific, high primary productivity, and differences in its fundamental configuration with gateway changes occurring at the eastern and western margins. Collectively, and individually, these different factors will have had implications on Pacific Ocean O2 distribution. To better understand the past oxygenation of Pacific waters amidst this backdrop of climatic and geographical changes we reconstruct iodine/calcium ratios from planktic foraminifera across multiple Pacific Ocean sites. Our I/Ca records extending from the mid-late Miocene through to Pleistocene show the progressive reduction in oceanic O2 content across the Pacific. We place these records in the context of changes in the Central American Seaway and the resultant changes in oceanic circulation.
3D evolution of localized plasma flow and its interaction with ambient field
Authors: Nakamura Rumi , Miyoshi Yoshizumi , Panov Evgeny
Published: February 2023

A major part of the transport of the magnetic flux and energy in the midtail and the near-Earth tail region is accomplished by local fast plasma jets, called bursty bulk flows (BBF) or flow bursts.  The interaction between BBF and ambient field plays an important role in the complex chain of solar wind-magnetosphere-ionosphere coupling processes. Furthermore, near-Earth flow braking/bouncing processes and associated magnetic and pressure disturbances in the transition region of the magnetic field configuration from tail-like to dipolar field  lead to complex localized current sheet restructuring. Associated energetic particle injection further effects the inner magnetosphere bringing in the source population of the plasma waves that cause electron accelerations as well as seed populations of the radiation belts. In this presentation we stress the importance of observations of BBF and dipolarization by covering extensive region, both near the equator and off-equator simultaneously, for understanding the energy transport processes by including both the field-aligned and perpendicular evolution of the flux tube.  By showing several examples of observations with fortuitous multi-spacecraft configuration, 3D nature of the interaction between BBF and ambient plasma will be discussed.   
East to West Acceleration of the Slip Rates Along the North Anatolian Fault and Its Implıcations Regarding Plate Tectonics and Earthquake Cycle
Authors: Yıldırım Sevil Cansu , Bulut Fatih , Garagon Aslı
Published: February 2023

Using GPS measurements, historical earthquake records, and instrumental earthquake data, we investigated GPS slip rates along the rupture zone of the 1668 Great Anatolian Earthquake (M8.1). We found three complete and one incomplete earthquake cycles since 1254 compiling all available historical and paleo-earthquake records in the literature. These records verified that a ~750-kilometer section of the North Anatolian Fault Zone was ruptured in 1668.  To simultaneously estimate segment-based slip rates and locking depths, we combined all available GPS measurements and modeled them using an arctangent approach. Slip rates are used to estimate preliminary inter-seismic slip storages assuming fault segments are fully locked after a mainshock. Large residuals between preliminary slip estimates and co-seismic slips indicate that the fault segments do not store slip for some time after a major earthquake. The creeping and locked stages vary in time and space, as our investigation revealed. Our results show that the slip rates along the NAFZ systematically increase from east to west suggesting that the Aegean extensional regime is the main driving force for the westward movement of the Anatolian Plate. Additionally, the locking depths show an east-to-west decreasing pattern verifying east-to-west thinning of crustal thickness along the Anatolian Plate. The earthquakes over the past three complete cycles and the current incomplete cycle indicate that the failure of the NAFZ begins in the east and moves westward reflecting a decelerating pattern. The failure is typically completed within a time period of 239±3 years.
First monitoring data of the post-project of geomorphological and geochemical rehabilitation in Lousal (Portugal)
Authors: Esbrí José María , Sanchez-Donoso Ramón , Muntaner Lucía , Martins Monica , García-Lorenzo Mariluz , Pereira Ana Margarida , Pinto Alvaro , Relvas Jorge , Lillo Francisco Javier , Tejedor María , Martín-Duque José Francisco
Published: February 2023

The rehabilitation of the Lousal mine in Portugal, carried out during September-November 2021 within the framework of the LIFE RIBERMINE project, is the first designed and built rehabilitation project in Europe where geomorphic reclamation methodologies have been combined with solutions aimed at addressing the problems caused by the generation of acid mine drainage and the mobilisation of potentially toxic elements (PTE).To assess the success and impact of the rehabilitation actions on the hydrochemistry of surface and groundwater in Lousal, four groundwater samples and two surface water samples were collected in May 2022. In each of the water samples, in situ dissolved oxygen, pH, conductivity was measured and PTEs and cation-anion content analysis were carried out by ICP - MS in an external laboratory. The post mine rehabilitation effects of recent less acidic leachates with lower metallic loads have not yet reflected correction to the pH or EC values, but they are significant in terms of oxidation reduction potential and presence of PTEs.The geomorphic evolution and development of vegetation in the reclaimed area has been monitored since the conclusion of the reclamation actions in November 2021. After the completion of the rehabilitation work, localised rilling processes were observed in areas where surface run-on entered the rehabilitation topography from adjacent areas. These erosive forms were corrected by extending limestone blocks over the eroded areas to create additional open limestone channels that manage incoming surface runoff and minimise its erosive potential. Throughout 2022, no signs of active erosion have reappeared in the restored area, demonstrating the success of the physical stabilisation actions applied in the intervention area.Vegetation has successfully developed during the year 2022, after manual sowing in November 2021. Currently, the intervention area is almost completely covered with herbaceous vegetation, with the exception of some small areas where the density of vegetation is lower.It is expected that the data and information obtained from the continued monitoring of this pioneering mine rehabilitation project will provide new knowledge and methodological innovations that can be applied to future mine rehabilitation projects around the globe with characteristics similar to those of the Lousal mine.
Photomosaic Mapping of Mars from the EMM Data
Authors: Almakhmari Ali , Atri Dimitra , Dhuri Dattaraj
Published: February 2023

In 2021, the Emirates Mars Mission (EMM) Hope probe reached the red planet to preach the United Arab Emirates effort to break the boundary of space sciences in the arab world. The Hope probe is equipped with three instruments: EMIRS (Infrared Spectrometer), EXI (Imager), and EMUS (Ultraviolet Spectrometer). Orbiting at a high altitude (19000km - 44000km) gives the probe an advantage over previous missions, as it is able to fully observe Mars and capture images from various locations with little time in between each image. As a result of the data accumulation since 2021, it is possible now to perform more complex scientific examinations. In this paper, we use the EXI observations of the Martian disk to build a full 2D colored map of Mars in the equirectangular projection. This paper will discuss in detail the photomosaic algorithm that was developed for building such a map while showing the results and their implications.
CALIPSO observations of cirrus cloud properties: investigation of latitude differences and possible aviation impacts
Authors: Li Qiang , Groß Silke
Published: February 2023

Cirrus clouds, forming in the cold upper troposphere, are composed of ice crystals with various sizes and nonspherical shapes. They are observed at all latitudes covering over 30% of the Earth’s surface. Studies reveal that they have a significant impact on the radiation balance of our planet and, consequently, on the climate evolution. The radiative effect of cirrus clouds is strongly determined by the cloud microphysical, thermal, and optical properties. Furthermore, global aviation affects the Earth’s radiation balance by inducing contrails and exerting an indirect effect on the microphysical properties of naturally-formed cirrus clouds. In the last decades, the Arctic surface has been warming faster than other regions of the globe, which is known as Arctic Amplification. The thin and small-coverage cirrus clouds over the Arctic are presumed to largely contribute to it. Unfortunately, however, the optical and microphysical properties of cirrus clouds over the Arctic and the exact role they play in the elevated warming of the Arctic are far from understanding. Compared with the intensive studies of cirrus clouds in the tropics and midlatitude regions, cirrus cloud measurements and model studies at high latitudes are sparse. In this study, we present the comparisons of the particle linear depolarization ratio (PLDR) and occurrence rates of cirrus clouds at midlatitudes (35–60 oN; 30 oW–30 oE) and high latitudes (60–80 oN; 30 oW–30 oE) based on the analysis of lidar measurements of CALIPSO in the years 2018–2021. The results show that cirrus clouds at high latitudes appear at lower altitudes than the midlatitude cirrus clouds. The PLDR and occurrence rates of cirrus clouds at high latitudes are smaller than the midlatitude cirrus clouds. Furthermore, air traffic over Europe was significantly reduced in 2020 (starting from March) and only moderately reduced in 2021 due to the COVID-19 pandemic. Under this condition we are able to study the difference in the aviation impacts on the cirrus cloud properties at high latitudes and midlatitudes.
Atmospheric concentrations of carbon dioxide and its isotopic composition in Krakow (Southern Poland) based on one-year CoCO2 measurement campaign
Authors: Skiba Alicja , Zimnoch Mirosław , Gorczyca Zbigniew , Maslouski Mikita , Marzec Michał
Published: February 2023

Regular, monthly based, diurnal measurements of atmospheric carbon dioxide concentration and its carbon isotope composition (13C/12C and 14C/12C ratios) were performed between 9 February 2021 and 1st February 2022 in Krakow, the second biggest city of Poland, populated by around 780,000 inhabitants. Spot air samples were collected in 3 l glass flasks every 4 hours from the roof of the building (50°04’ N 19°55’ E 220 AMSL, ∼ 20 m above the surface) during each measurement campaign. A total of 72 air samples were collected during 12 measurement campaigns. The samples were analyzed with Picarro G2101i (Picarro Inc., Santa Clara, California, USA) to determine the carbon dioxide. After that, the samples were analyzed with Isotope-Ratio Mass Spectrometry (IRMS) and Accelerator Mass Spectrometry (AMS) in order to determine δ13C and Δ14C composition. The carbon dioxide concentration during the campaign ranged from 404 ppm (7 September 2021) to 617 ppm (1 February 2022) with the one-year average of 463 ppm. δ13C ranged from -14.79 ‰ (1st February 2022) to -8.5 ‰ (7th September 2021). The one-year average results of Δ14C were -35 ‰.Furthermore, measurement of gas concentration and its isotopic composition, along with the use of the isotope-mass balance, allowed determination of fossil fuel-related and biogenic contributions to the total measured CO2 load during campaign days, allowing to characterise the diurnal and seasonal variability of those components in the urban environment. Based on the obtained results, a dataset dedicated for the validation of WRF-CHEM high-resolution simulations of the city atmosphere has been prepared. ACKNOWLEDGEMENTSThe presented work was funded by the CoC02 project, which has received funding from the European Union's Horizon 2020 research and innovation programme under Grant Agreement No. 958927 and the "Excellence Initiative - Research University" program at AGH University of Science and Technology.
Comparison of Neural network based and Kernel based Machine Learning approaches for daily forecasting of reference evapotranspiration in data scarce regions
Authors: Mandal Nehar , Chanda Kironmala
Published: February 2023

Efficient estimation and forecast of reference evapotranspiration (ETO) is crucial for water resources management and for developing an efficient irrigation practice that will help better utilization of scanty water resources. This is a more challenging task in data scarce regions. This study aimed at multi-step ahead prediction of ETO across different cropping seasons and agro-climatic regions in India with six Machine learning (ML) based techniques using globally available fifth-generation European Centre for Medium-Range Weather Forecasts (ECMWF) gridded reanalysis products (ERA5). For real-time, one-day, two-day, and seven-day ahead prediction of ETO, this study evaluates and compares the capability and prediction accuracy of deep learning algorithms, i.e., Support Vector Regression (SVR), Multivariate Adaptive Regression Splines (MARS), Random Forest (RF), Multi-Layer Perceptron (MLP), one-dimensional Convolutional Neural Network (CNN) and Long Short-Term Memory (LSTM). ML based models were developed using meteorological observations along with ERA5 inputs at three meteorological stations: Nagpur, Hyderabad and Bhubaneswar. The results indicate that MLP, SVR and CNN outperform other ML algorithms. High performing models, one each (MLP and SVR) from neural network-based models and kernel-based models respectively, are further utilized to scale up the analysis for gridwise ETO forecasting across the whole of India. The Global Land Evaporation Amsterdam Model (GLEAM) dataset has been used as reference to evaluate gridwise ETO forecasts. ETO predicted by MLP model shows better agreement with GLEAM ETO values during the Rabi cropping season (October-March) (MAE = 0.103 mm/day and NRMSE = 3.9 %) than during the Kharif season (June-September) (MAE = 0.151 mm/day and NRMSE = 4.5 %). As expected, the accuracy of the models drops with increase in the prediction horizon from real-time to seven-day; for instance, with MLP, MAE = 0.146 mm/day, R2 = 0.955 for real-time and MAE = 0.173 mm/day, R2 = 0.939 for seven-day ahead prediction over arid agro-climatic zone during Rabi season. However, even the minimum forecast performance observed in the semi-arid tropics region during Rabi season is reasonably good (MAE = 0.396 mm/day, R2 = 0.704 for real-time evaluation and MAE = 0.445 mm/day, R2 = 0.56 for seven-day ahead). This strengthens the potential of the proposed models for multi-step ahead ETO forecasting across varied cropping seasons and agro-climatic regions without depending on meteorological station data.
An Integrated Health Assessment of an Agriculture-Dominated River Basin in India
Authors: Dhal Lingaraj , Kansal Mitthan Lal
Published: February 2023

Watersheds are geographically distinct landscape features with complex webs of interactions among physical, ecological, and social factors. Thus, watersheds are complex and dynamic systems. In addition, watersheds offer various ecosystem services that are crucial for society. Their ability to deliver these services is determined by the current state of the watershed. Therefore, the watershed health assessment is essential for the efficient management of the watershed. The purpose of this research is to comprehensively evaluate the watershed health using a risk-based (Reliability-Resilience-Vulnerability) framework for the 30 watersheds of the Budhabalanga River basin in India. To accomplish this hydrological modelling with Soil & Water Assessment Tool (SWAT), a remote sensing approach and field data have been used. The SWAT model is calibrated from 1995 to 2009 and validated from 2010 to 2017 with NSE > 0.65, R2 > 0.70, and PBIAS < ±10.  To determine the three most important sub-indicators of watershed health i.e., reliability, resilience and vulnerability (R-R-V), suitable criteria and acceptable thresholds are taken into account.  Using the sub-indicators an Integrated Watershed Health Index is developed for all watersheds during the period 2000 to 2020.  Further, the change detection approach is used to study the temporal variation of watershed health during the last two decades. The study revealed that the upstream watersheds are healthier than the other watersheds. In addition, the study will be useful for the watershed managers of the Budhabalanga River basin to prepare a strategic road map for sustainable watershed management. The proposed method can be used as a handy tool for watershed health assessment for any other watershed.
Does mucilage governs rhizosheaths development under drying and wettingCycles?
Authors: Rahim Riffat , Amelung Wulf , Siebers Nina
Published: February 2023

Mucilage helps in rhizosheath formation. Rhizosheath is known as the soil attached to plant roots when excavated from the soil after gentle shaking. However, very little is known about mucilage role in the development of rhizosheath under various alternate drying and wetting cycles. This study is design to test the formation of rhizosheath by inducing alternate drying and wetting cycles in the presence of chia seed mucilage. For this experiments, we have used sterilized and unsterilized soils with different clay contents. Sterilized soils are often used in experiments related to soil microbiology. But for underground process like rhizosheath formation it’s very less common. Therefore, we intended to use sterilized and unsterilized soils with 22% and 32% clay contents to check the rhizosheath formation. Sterilized soils were autoclaved at 121oC /103 kPa for 30 min on three consecutive days. After that soils were incubated at 25oC and drying and rewetting cycles were induced to a water holding capacity at field capacity of 75% at regular four intervals. Soils were treated with 0.3% [mg dry mucilage/ g of water] of chia seed mucilage and artificial roots made of flax cord will be used as modeled plant roots. Rhizosheath formation were examined after four wetting and drying cycles. Our preliminary results indicated significantly higher rhizosheath development in unsterilized soils as compared to sterilized soils. In parallel study, we also planned to check soil aggregation by scanning electron microscope (SEM).The quantitative findings of analysis will be presented and discussed.
Visualizing reaction zones in tidal subterranean estuaries using physical tank experiments
Authors: Grünenbaum Nele , Greskowiak Janek , Binte Delwar Rezwana , Massmann Gudrun
Published: February 2023

In coastal aquifers, terrestrial freshwater and seawater mix and form typical compartments in the subsurface (subterranean estuary, STE), a zone of intense biogeochemical reactions. Flow and transport processes are mainly driven by density differences and- if present- tides. Typically, an upper saline plume is encountered overtopping a freshwater discharge tube and a saltwater wedge. Contrary to the general view of the hydraulic conditions in the STE, latest studies proclaim that the subsurface salinity distribution is less stable and more dynamic than previously thought, especially under the influence of strong morphodynamics. Also, the occurrence of the phenomena of fingering flow has been observed in modelling studies. In this study, physical tank experiments were conducted to compare unstable and stable flow conditions in the STE with respect to the formation of iron oxides that may form in the transition zone between the oxygen-free, iron(ii)-containing, terrestrial freshwater and the oxygen-rich seawater. The results illustrate how biogeochemical processes in the STE are linked to the hydrodynamics as salt fingering flow strongly influenced the location and extent of ferric iron oxidation and the precipitation of Fe(III)hydroxides.
Integrating omics, machine learning, and process-based land surface model to predict hydroclimate feedbacks of microbial functions and its implication for soil carbon emission
Authors: Song Yang , Fan Changpeng
Published: February 2023

Climate change is altering the spatiotemporal pattern of precipitation toward more extreme conditions. However, it’s still unclear how a more variable hydroclimate influences soil biogeochemical cycling and resultant soil carbon emission. One key challenge is our limited understanding of how hydroclimate coupling with other environmental drivers regulates the composition and functions of soil microbial communities. Moreover, how this environmental feedback of soil microbial communities mediates soil biogeochemical processes. To overcome this challenge, we integrated published metagenomics datasets across the US to identify eight general soil enzyme functional classes (EFCs) involved in soil carbon (C), nitrogen (N), and Phosphorus (P) cycles. We then integrated this omics-informed microbial functional information with the corresponding hydroclimate and other environmental data to train and test a machine learning (ML) pipeline for predicting the spatial distribution of EFC composition across the US domain and its variability with changing hydroclimate. This ML-predicted microbial functional feedback to changing hydroclimate was finally coupled with the Community Land Model (CLM5.0) to assess its impact on microbially-mediated soil carbon emission. Our study showed that soil enzyme functional composition is sensitive to changing hydroclimate. Microbial communities decrease the investment in EFCs involved in SOM decomposition under drying conditions. Incorporating this microbial feedback to hydroclimate into the CLM5.0 captured soil carbon dynamics in the water-limited region. Output from this study, including the gridded EFC composition dataset and coupled model framework, can be applied to mitigate the uncertainty in projecting soil carbon-climate feedback under changing hydroclimate.
Classification of snow and rainfall using commercial microwave links
Authors: Øydvin Erlend , Hagland Rasmus Falkeid , Nilsen Vegard , Wolff Mareile Astrid , Kitterød Nils-Otto
Published: February 2023

The use of Commercial microwave links (CMLs) to estimate rainfall has been under investigation for the past 15 years. CMLs still seem like a promising supplement to standard measurement methods. So far, CMLs have almost exclusively been applied for rainfall only situations. It is expected that different precipitation types affect the CML signal strength and error sources differently. For CML applications in high latitude countries with frequent and extended periods with snowfall and mixed precipitation, an extension of the classification methods for these precipitation types is needed. In this presentation we study how the CML signal attenuation is affected by different precipitation types and how those can be used to classify the different events. We use nearby disdrometers as a ground truth reference and CML data from different climatological conditions in Norway.
Swarm - status after almost 10 years in orbit and the way forward
Authors: Stromme Anja
Published: February 2023

The three satellite Swarm constellationon is on a mission to unravel our planets invisible shield - the Earths magnetic field, and Swarm is after almost 10 years in orbit still in excellent shape and is still contributing to a wide range of scientific studies  from the core of our planet via the mantle, the lithosphere and out to the ionosphere and the interaction with the Solar wind. In this talk we will present an update on the status of the Swarm mission, including the health and quality of the spacecrafts , instruments and data products, examples from scientific studies  and outline our plans for the future.
Consideration of positional uncertainty of sea-surface platform for GNSS-A seafloor positioning
Authors: Zhao Shuang , Yokota Yusuke
Published: February 2023

As the unique approach to obtain centimeter-level seafloor positioning information, Global Navigation Satellite System-Acoustic ranging combination technique (GNSS-A) (Spiess, 1985) has drawn increasing attention and plays an important role in ocean engineering and marine geoscience research (Gagnon et al. 2005; Tadokoro et al. 2006; Watanabe et al.2014; Yokota et al. 2016; Yang et al. 2018).GNSS-A positioning accuracy is significantly restricted by temporal and spatial variation errors related to propagation velocity of acoustic signals, the bridge medium to connect sea-surface platform and seafloor stations. Valuable investigations focusing on sound speed structure (SSS) modelling and inversion have been released and contribute to the GNSS-A performance improvements (Fujita et al. 2006; Ikuta et al. 2008; Honsho et al. 2017; Yokota et al. 2019; Watanabe et al. 2020; Yang et al. 2020; Yokota et al, 2022; Xue et al. 2023, in prep). It’s promising to progressively suppress SSS errors effect on seafloor positioning capability based on the increasingly refined SSS model policy.Besides concentration on SSS errors modeling and corrections, additional consideration of positional uncertainty of sea-surface platform, one of vital parts of entire GNSS-A observation system, is reasonable for refined seafloor positioning policy. Currently, joint/total adjustment model and parameter estimation of the transducer and seafloor transponder for underwater precise point positioning have been published (Zhao et al. 2021). Furthermore, for seafloor geodetic network scene, numerical tests considering the positional uncertainty of sea-surface transducer were conducted. Further research may be hopeful to evaluate and control error propagation effect on seafloor positioning from sea-surface segment and helpful for usage of more flexible platform.
Taking Stock of Greenhouse Gas Emissions in the Geosciences: an Example from GFZ Potsdam
Authors: Sens-Schönfelder Christoph , von Blanckenburg Friedhelm , Kaiser Knut
Published: February 2023

The basis of all serious efforts to reduce greenhouse gas emissions is an inventory of the emissions caused by the various activities of an organisation. The Greenhouse Gas Protocol provides the guideline for establishing such an inventory. The German Research Centre of Geosciences GFZ Potsdam used these guidelines to estimate its greenhouse gas emissions for 2019. Besides the estimation of quantities (e.g. travel distances or hotel nights) which is an administrative challenge, the specific emissions per unit of quantity -- the Global Warming Potential -- play a crucial role. Unequivocal accounting of emissions from construction work is another task of great complexity.  A compilation and standardisation of these values within the research community would greatly simplify the compilation of GHG inventories and help to improve their comparability. Controversy inevitably will arise regarding the design of mitigating measures, like purchase of electricity and heat from renewable sources (which generates extra costs) the compensation of emissions (of which the effectiveness is contested), and even to shifting scientific activities away from those with high greenhouse gas footprints (which may conflict with scientific needs). Building awareness for emissions caused by academic activities and careful communication of mitigation options comprise the first necessary steps en route to low (or net-zero)-emission science.
Mass change of Antarctica from new GRACE/GRACE-FO releases
Authors: Jenny Barbara , Hansen Nicolaj , Jensen Tim , Forsberg René
Published: February 2023

An important application of the NASA/GFZ GRACE and GRACE-FO satellites is the derivation of ice mass changes in the arctic regions from the gravity field changes. Looking at climate change, it is important to know how fast the ice caps are melting for global sea level rise estimation and validation of climate models. We use recently released L2 GRACE/GRACE-FO models, including the latest CSR release 6.1, which show major improvement over earlier models, especially for Antarctica, as well as the latest TU Graz models.  We also compare the GRACE results to a new surface mass balance model, and joint high-resolution inversion with ESA’s Earth Explorer CryoSat altimetry data, highlighting areas of dynamic changes and giving a higher resolution on the main mass change areas. The study is a precursor to a project for demonstrating use of Level-1 laser data for glacial change detection.
Late Ediacaran macrofossils in storm and debris flow deposits reveal the allochthonous nature of many Ediacaran palaeocommunities from the Nama Group, Namibia
Authors: O'Connell Brennan , McMahon William , Liu Alex
Published: February 2023

Our ability to compare late Ediacaran macrofossil assemblages between global localities and place firm constraints on the palaeoecology of Ediacaran biota is limited by a paucity of detailed palaeoenvironmental reconstruction and sedimentological facies analysis for many fossil-rich strata. Here, we present sedimentological evidence for ubiquitous transport of soft-bodied macro-organisms in storm deposits of the Aar Member, Nama Group, Namibia. Higher in the succession, transport of biomineralizing taxa in debris flows of the Spitzkop Member reveals further evidence for mass transport.

Fossiliferous sandstone beds of the Aar Member often have sharp bases with erosional scours, flute casts, tool marks, and elongate parallel syneresis cracks. Upper plane stage beds pass both upward and along strike into 3D dunes and 3D ripples (hummocky cross-strata), to 2D wave-ripple lamination, and finally to silty sandstone beds. Facies and bedform transitions occur over short distances (m-scale to decameter-scale) before event beds pinch out into mudstone. Drawing on constraints from flume experiments, these beds require rapid deceleration and sediment aggradation under combined unidirectional and oscillatory flow conditions – common during storm events. Ediacaran soft-bodied macrofossils such as Pteridinium are aligned with flow or twisted, jumbled, and overturned in event beds – i.e., they are entrained and transported in storm deposits and are not preserved in situ. Other soft-bodied macrofossils such as Ernietta can colonize the sediment surface after events and may be in situ. In some Spitzkop Member localities, biomineralizers such as Cloudina and Namacalathus are preserved in cm- to m-scale stacked carbonate beds (recording many events), have scoured bases with tool marks, and are graded and capped by bypass surfaces. Individual fossils (clasts) within beds are chaotic in orientation or imbricated. Erosive bases and chaotic arrangement of clasts are typical of gravity-induced debris flows in deep-water and therefore many biomineralizing taxa are also not in situ.

Our findings have implications for palaeoecological interpretations of Ediacaran taxa and for research into potential late Ediacaran extinction events. Consideration of palaeontological and sedimentological data from late Ediacaran shallow marine sedimentary sections in the U.K., Australia, and Canada further permits direct comparison between our Namibian data and the Ediacaran palaeocommunity compositions of comparable depositional environments.
Land plant responses during extinction events linked to large volcanic eruptions – is there a common pattern?
Authors: Lindström Sofie , Galloway Jennifer M , Tegner Christian , Bos Remco , van der Schootbrugge Bas
Published: February 2023

Large-scale volcanic activity during the formation of large igneous provinces (LIPs) were contemporaneous with almost every mass extinction event in Earth’s history, and LIP activity is believed to have caused or contributed to at least three, if not all, Big Five mass extinctions. However, compared to the marine fossil record, the effects of the volcanism on the terrestrial plant record is still poorly understood. Extinctions in the animal record during major biotic crises in Earth history are not mirrored by comparable major changes in land plants. Despite being sedentary organisms land plants have evolved adaptations to cope with adverse changes in the environment which may provide autecological advantages compared to animals. Despite their remarkable resilience, land plant communities were still affected in multiple ways during LIP-induced extinction events. During the end-Triassic mass extinction (201.56–201.36 million years ago) emissions of greenhouse gases, sulfur dioxide and aerosols, halocarbons, polycyclic aromatic hydrocarbons, Hg and heavy metals from magmatic activity, as well as sea-level changes, during the emplacement of the Central Atlantic Magmatic Province (CAMP) are considered to have severely stressed land plants. This is exemplified by major changes in ecosystem structure in palynological records, a rise in microscopic charcoal abundance indicating increased wildfire activity, enhanced reworking of palynomorphs indicating increased soil erosion, acid rain damages on macroplant leaves, and increased abundances of abnormal spores and pollen indicating mutagenesis from Hg-toxicity and/or ozone layer depletion. Several of these land plant responses have also been observed during other extinction events contemporaneous to LIP activity. Here, we compare and discuss some of the changes in common between different biotic crises to evaluate whether there is a common pattern or not.
Development, application and validation of a flood damage model for multi-year crops (vineyards and orchards).
Authors: Petruccelli Natasha , Domeneghetti Alessio , Marinelli Ludovica , Molino Maria Chiara , Brath Armando
Published: February 2023

Floods are one of the most frequent and widespread natural hazards globally. Over the past 20 years, the number of floods has more than doubled from the previous two decades, resulting in annual losses of around $40 billion worldwide. Among the various sectors exposed, agriculture is certainly the most vulnerable to events of this type, given its close dependence on weather conditions. However, although floods constitute the second most serious threat to agricultural areas, causing total production losses of up to 20%, their impacts are still difficult to assess. The perceived minor importance of agricultural losses compared to those of other assets (e.g. infrastructures, residential and industrial buildings, cultural assets), together with a lack of observations, have led to development of few approaches for crop damage assessment in case of floods, in most of the cases also characterized by considerable imprecisions.In compliance with the requests of the Floods Directive (Directive 2007/60/EC), a model has been developed to quantify the direct and tangible flood-related damages to the multi-year crops (such as vineyards and orchards). The loss of perennial plant material in the years following the flood and thus, the expected damage, is evaluated based on hazardous variables (e.g., water depth, inundation duration, season of occurrence, etc.), crop (e.g., typology, technological solutions, yield, etc.) and economic conditions (product price, production costs, etc.). The model relies on several damage curves, by means of which it is possible to estimate the total absolute damage for each flooded agricultural portion.The expert-based model has been developed referring to the Emilia-Romagna region (Northern Italy) and validated using real damage records collected after the flood of the Secchia river (2014). Results are convincing, reproducing the damage suffered by farmers with a good approximation (errors of about 12-20%).
Fault characterization using seismic and DAS recordings at the Hengill geothermal area, Iceland
Authors: Goertz-Allmann Bettina P. , Langet Nadège , Baird Alan , Kühn Daniela , Kaschwich Tina
Published: February 2023

The Hengill geothermal area is located in southwest Iceland on the plate boundary between the North American and Eurasian plates and is one of the most active seismic zones on the island with thousands of natural earthquakes per year. In addition, seismicity is induced due to active production and injection operations, including the two largest geothermal power plants in Iceland, Nesjavellir and Hellisheiði. In addition, this area is the next target region for the Iceland Deep Drilling Project (IDDP) in search for supercritical geothermal fluids. Detecting and imaging fault zones at high resolution is therefore an important contribution to evaluate the optimum drilling location. We analyze thousands of microseismic events in the area that occurred between December 2018 and August 2021. These events were recorded on different permanent and temporary seismometer networks in the area. In addition, we recorded distributed acoustic sensing (DAS) data along a 25 km long fiber optic telecommunication cable near the Nesjavellir geothermal power plant. We analyze event clustering with a waveform cross-correlation approach and find a clear spatial separation of event clusters delineating planar structures. Clusters experience different temporal evolutions where some develop steadily and others as sudden bursts. Spatial variations of Gutenberg’s b-value and event stress drops show patterns consistent with tomographic seismic velocity inversions. Furthermore, focal mechanisms indicate very consistent source mechanisms within selected event clusters. Along the fiber path, we study waveform characteristics, which correlate with mapped geological features.  Data segments that are recorded where the fiber crosses fault zones exhibit long-tailed codas that may indicate trapping of seismic energy in low-velocity zones around active faults.
Meteorological Feedbacks on a Decaying Alpine Glacier
Authors: Shaw Thomas , Buri Pascal , McCarthy Michael , Miles Evan , Ayala Álvaro , Pellicciotti Francesca
Published: February 2023

A developed boundary layer can decouple a glacier's response to the ambient meteorological conditions, though glacier retreat can limit this boundary layer development and increase a glacier’s sensitivity to climate change. We explore six years of distributed meteorological data on a small Swiss glacier in the period 2001-2022 to highlight its changing response to local conditions. We find an increased sensitivity (ratio) of on-glacier to off-glacier temperature changes as the glacier has retreated and its debris-cover area expanded. The glacier lost ~60% of area since 1994, coinciding with notable frontal retreat post 2005 and an observed switch from down-glacier to up-glacier winds in the upper ablation zone from 2001-2022. Increased sensitivity to external temperature changes is thus driven by a combination of increased up-glacier winds and the larger extent of ice exposed to warm air at a retreating, debris-covered glacier terminus. Calculated sensible heat fluxes on the glacier are therefore increasingly determined by the conditions occurring outside the boundary layer of the glacier, highlighting the expected negative feedback of smaller Alpine glaciers as the climate continues to warm and experience an increased frequency of extreme summers.
Teachers training on climate change
Authors: Ginoudi Athina
Published: February 2023

We will present the training of secondary school science teachers in the region of Crete on climate change issues. The training is in the framework of a national educational program that includes topics related with climate change, like the drivers, the impacts and the measures for sustainability. Teachers participate actively in the workshops and are involved in hands-on activities and experiments that simulate climate phenomena in a simple way. The aim is to educate further their students in the climate science through topics that fit in the national science curriculum. The teachers are also trained in the hub that is developed by researchers of the University of Crete that is around the atmospheric monitoring station in Finokalia in Crete and is focused on the expertise of the Greek research group while it also adapts international scientific knowledge to the local special conditions. After training, teachers have the possibility to collaborate in groups to prepare their own lesson plans that are appropriate for their students. They also implement the activities in the classroom, assess the implementation in practice and propose potential improvements. The proposed methodology is the inquiry based learning that promotes the active participation of the trainees.