bluuebunny/crossref_metadata_2025 huggingface dataset:
Top-down downscaling of a global emission inventory in the area of Northern China
Authors: Shi Xiaoqin , Brasseur Guy
Published: March 2022

This study develops top-down methods to downscale a global emissions inventory provided by the Copernicus Atmosphere Monitoring Service (CAMS) from a resolution of 10 kilometers to a resolution of 1 kilometer in the area of Northern China. Information extracted from various high-resolution proxies is used as weight factors to distribute the original emissions in 10x10 km grids to emissions in 1x1 km grids. Among five lumped emissions sectors, three of them (transportation, residential and agriculture) are area sources while two of them (industrial and energy) are point sources. For emissions from area sources, the original emissions are first bilinearly interpolated on defined 1x1 km grids in order to smooth spatial distribution of emissions. Correspondingly, the point source emissions are conservatively converted into 1x1 km grids. To downscale the emissions of the transportation sector, road maps including motorways and railways from OpenStreetMap are processed to derive total road length in every 1x1 km grid, which is summed up by weights of different road types. Cropland fraction is used to weight agricultural emissions of 1x1 km grids. Population is taken as a proxy for downscaling of residential emissions. Emissions of energy sector (mainly from power plants) are downscaled based on annual emissions of nitrogen dioxide from individual power plants due to their good correlation with annual emissions of other pollutants. Accuracy of energy sector downscaling is depending on how many power plants are taken into account. Downscaling of industrial sector emissions takes population in industrial area as proxy (weight factor); several proxies are needed here to generate 1x1 km grids covered by industrial area with defined properties. Weighted values of 1x1 km grids are rescaled to conserve the total emission in area of 10x10km grids. Two comparative simulations driven by the CAMS emissions (10 km) and the downscaled emissions (1 km) are performed to test the sensitivity of simulated pollutants to emission resolutions using model of Weather Research and Forecast coupled with Chemistry (WRF-Chem).
Non-tectonic-induced stress variations on active faults
Authors: Cai Yiting , Mouyen Maxime
Published: March 2022

Non-tectonic processes, namely solid earth tides and surface loads such as ocean, atmosphere, and continental water, constantly modify the stress field of the Earth's crust. Such stress perturbations may trigger earthquakes. Several previous studies reported that tides or hydrological loading could modulate seismicity in some areas. We elaborate on this idea and compute the total Coulomb stress change created by solid earth tides and surface loads together on active faults. We expect that computing a total stress budget over all non-tectonic processes would be more relevant than focusing on one of these processes in particular. The Coulomb stress change is a convenient approach to infer if a fault is brought closer to or further from its critical rupture when experiencing a given stress status. It requires to know 1) the fault's rake and geometry and 2) the value of the stress applied on it, which we retrieve from a subduction zone geometry model (Slab2) and a loading-induced Earth's stress database, respectively. In this study, we focus on the Coulomb stress variations on the Kuril-Japan fault over the few last years. By applying this method to the entire Slab2 catalogue and other known active faults, we aim at producing a database of non-tectonic-induced Coulomb failure function variations. Using earthquakes catalogues, this database can then be used to statistically infer the role of the non-tectonic process in earthquakes nucleation.
Invasive mesquite (Prosopis juliflora) reducing soil nitrogen and carbon oxides emissions during rewetting in the Dead Sea valley, Israel.
Authors: Gelfand Ilya , Yagle Isaac
Published: March 2022

Invasive species are modifying invaded ecosystems, changing their species composition, diversity and stability, and affecting overall ecosystem functioning. A recent survey in Israel found that multiple planted populations of mesquite (P. juliflora) became invasive and currently invade 690 km2 of the Dead Sea area, Negev desert, Jordan Valley and the Arava Valley. In the Jordan, the extent of area invaded by Prosopis is ~3 times the area in Israel (>1800 km2), with numerous populations of P. juliflora invading the region around the Dead Sea, mainly in humid habitats with continuous water flow (e.g. river banks and irrigated land). Despite increasing presence and high risk of further spreading, the impact of mesquite encroachment on ecosystem N and C cycles in invaded areas of Israel and Jordan are currently unknown. We studied an established Prosopis population in Khatsason stream mouth on the western coast of the Dead Sea. We have compared emissions of nitrous and nitric oxides (N2O and NO) and carbon dioxide (CO2) during a rewetting event from soil under the canopy of P. juliflora with those from soil under the canopy of the native Red Thorn acacia (Vachellia gerrardii) and to the bare soils far from trees. We have found that overall dynamics of soil trace gases emissions during the rewetting were same under canopies of both, invasive and native species. Each trace gas, however, had different post-rewetting emission pattern, CO2 emission reached maximum immediately after the rewetting (~15 min), soil N2O flux peaked ~1 hour after and soil NO emissions increased during the measurement period of ~ 5 hours without sign of decrease.

The magnitudes of emissions, however, were strikingly different under canopies of the two species. After the rewetting, soils under native V. gerrardii emitted ~25 times more N2O (peak of ~ 90 µg N m-2 min-1) and ~4 times more NO and CO2 (peaks of ~6 µg N m-2 min-1 and 20 × 103 µg C m-2 min-1, respectively). Our results pointing on a potentially slowing-down of the N and C cycles under the canopy of the invasive mesquite. This is surprising because mesquite invading an ecosystem dominated by similar, at list morphologically, N-fixing acacia. Biogeochemical drivers of the observed post-rewetting emissions, however, requiring further research.
Towards homogenisation of Swiss manual snow series: Investigating the sensitivity of break point detection performances of ACMANT, CLIMATOL, and HOMER
Authors: Buchmann Moritz , Coll John , Aschauer Johannes , Begert Michael , Brönnimann Stefan , Chimani Barbara , Resch Gernot , Schöner Wolfgang , Marty Christoph
Published: March 2022

Measurements of snow depth can vary dramatically over small distances, and as with any other meteorological variable, snow depth time series are affected by inhomogeneities or break points. Such inhomogeneities can arise due to e.g.; changes of instrumentation, changes to station location and observer practices, or changes in the local environment such as urbanisation or plant growth.

In order to analyse and monitor variation in snow depth time series accurately, homogenised snow data series are required. In deriving such homogenised series, it is essential  to understand the characteristics and impacts of inhomogeneities. Having applied some pre-selection criteria to identify candidate series, time series homogenization for 184 Swiss snow depth series was performed using ACMANT, Climatol, and HOMER, three state-of-the-art break detection algorithms.  For the 91 year base period of 1931-2021, we investigated which method and set-up worked best for detecting breaks in this network of Swiss snow data series. The approach identified valid break points in 25% of the series, with HOMER identifying more valid breaks than either ACMANT or Climatol.  By evaluating the network using multiple methods, there is more confidence that the results can be applied to snow time series with insufficient metadata or no  immediately nearby reference  stations in order to include them in future homogenisation efforts.
Monitoring of Indonesian Volcanoes with I06AU infrasound array
Authors: Gheri Duccio , Marchetti Emanuele , Belli Giacomo , Le Pichon Alexis , Ceranna Lars , Hupe Patrick , Mialle Pierrick , Hereil Philippe
Published: March 2022

Detecting and notifying ongoing volcanic explosive eruptions can support the activities of the Volcanic Ash Advisory Centres (VAAC) in their contribution to the International Airways Volcano Watch. However, local monitoring systems are missing on many active volcanoes. Here, the use of a global monitoring that, even with lower reliability, can allow a fast response. Many studies have shown so far the utility and potential of long-range infrasound monitoring for this aim, but still open questions remain concerning the real efficiency and reliability of such a system.

In this study we investigate the potential of the infrasound network of the International Monitoring System (IMS) of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) to detect volcanic explosive eruptions at large distances. We apply a procedure based on the Infrasound Parameter (IP) calculated from a single array to selected volcanoes by accounting for realistic infrasound propagation conditions.

The procedure was applied to data recorded by the I06AU infrasound array (Cocos Island) between January 2012 and December 2019 and targeting Indonesian volcanoes at source-to-receiver distances ranging between 1000 and 2000 km, where activity from 11 volcanoes was reported in the period of analysis with an energy spanning from mild explosions to VEI4 eruptions.

The system reliability was evaluated from the ratio between real ones and the total number of notifications provided from I06AU array for each volcano.

The IP was calculated following previous studies and improved with new constraints accounting for the source strength and signal persistency. These allowed us to improve significantly the system reliability for events VEI3 or greater and strongly reduce the number of false alerts. Still, undetected explosive events remain due to unfavorable propagation conditions and unresolved ambiguity due to short spacing among volcanoes with respect to the array. We propose to solve this last issue by considering volcanic sectors rather than single volcanic edifices. Instead of a notification for a single volcano, an alert for an area of interest could be issued to draw the attention and trigger further analysis of satellite images by the VAACs.

This study is performed to improve the Volcanic Information System (VIS) proposed and developed in the framework of FP7 and H2020 ARISE projects.
A statistically driven spatial model to delineate (dis)connected debris flow release areas
Authors: Scorpio Vittoria , Steger Stefan , Pitscheider Felix , Comiti Francesco , Marco Cavalli
Published: March 2022

Debris flow processes are known to contribute substantial amounts of sediment to the fluvial system in mountainous areas, such as the Alps. In fact, debris flow release areas represent relevant sediment sources that should be taken into account when mitigating flood hazards for lower order streams. However, terrain that frequently produces debris flows is not necessarily connected to the channel network while structurally connected areas may often not produce debris flows. Therefore, the relevance of an area to contribute debris flow material to a channel mainly depends on the co-occurrence of two aspects: a high debris flow susceptibility which coincides with a high structural sediment connectivity.

In this work, we present a novel data-driven approach that allows to identify areas that are both, susceptible to debris flow initiation and structurally connected to the main channel network. The methodology was developed for a debris flow prone basin located in the Dolomites (Italy) and further tested for other catchments that exhibit different geomorphological settings.

The methodical approach was based on the manual mapping of event-specific connected and disconnected debris flows areas that allowed to (i) calibrate a statistically based debris flow release susceptibility model and (ii) to derive quantitative thresholds for the previously derived connectivity index map (IC). The joined results reflect debris flow connectivity-susceptibility maps that were evaluated from numerous perspectives, including the evaluation of the spatial transferability of the approach.

We present (i) quantitative IC index thresholds that allow to discriminate connected from disconnected debris flow release areas, (ii) well-performing debris flow release susceptibility models and (iii) joint debris flow connectivity-susceptibility maps that allow identifying zones that are differently relevant in terms of debris flow connectivity. Issues related to the geomorphic plausibility of the results and the spatial transferability of the approach are discussed. The proposed approach requires few basic input data sets and therefore will be applied over vast areas with similar geomorphological settings.
Detrital zircon evidence for exotic elements in the southern Neotethys: A provenance study of Triassic-Eocene rock units in the Kyrenia terrane, Northern Cyprus
Authors: Glazer Adar , Avigad Dov , Morag Navot , Güngör Talip , Gerdes Axel
Published: March 2022

Situated between Africa and Eurasia in the eastern Mediterranean, the island of Cyprus has developed on the northern margin of the southern Neotethys by the accretion of three terrains, the Mamonia complex, the Troodos ophiolite, and the Kyrenia terrane. The Kyrenia terrane comprises a tectonic stack of Triassic to Eocene rock units interleaved with basic and acid volcanics and minor metamorphic inliers, alongside an Oligocene-Miocene flysch. Our U-Pb-Hf detrital zircon investigation in the Kyrenia Triassic to Eocene section reveals a large amount of Neoproterozoic zircons (950-600 Ma), alongside Silurian (∼430 Ma), Carboniferous (∼300 Ma), Triassic (∼240 Ma), and Upper Cretaceous (∼85 Ma) zircons. The Precambrian age profile of all three studied units resembles that of Paleozoic sandstones of the Tauride Block, as well as that of Paleozoic and Mesozoic sandstones found across North Africa. It is interpreted as reflecting the reworking of Paleozoic sandstone units from the Taurides or other peri-Gondwanan source. The presence of a substantial proportion of ~300 Ma zircons, as early as in Triassic sediments of the Kyrenia, is of significant interest because Carboniferous magmatism is confined to the Paleotethyan realm which is traced north of the Taurides. Deposition of the Kyrenia sequence closer to a Northern Tethyan province would better fit its detrital zircon signal. The detrital signal of the Kyrenia, indicative for Eurasian terranes north of the Mediterranean, also differs significantly from that of the Mamonia Complex (SW Cyprus) in which only Afro-Arabian sources are distinguished. Thus, in view of its unusual detrital zircon content, the Kyrenia sequence stands out in the Eastern Mediterranean as an exotic rock pile that cannot be straightforwardly correlated with its neighboring geologic environment.
4D physics-based pore pressure monitoring in the shallow subsurface of Groningen, the Netherlands
Authors: Fokker Eldert , Ruigrok Elmer , Hawkins Rhys , Trampert Jeannot
Published: March 2022

We previously developed a physics-based model relating changes in pore pressure and vertical stress to seismic velocity variations and validated the model in a small area of Groningen gas field. Using the entire Groningen seismic network, near-surface velocity changes are estimated over a three-year period, using passive image interferometry. Using our developed model, we invert these observations of velocity change for pore pressure variations as a function of space and time, and thus we construct a 4D pore pressure model for the shallow subsurface of Groningen. Pressure-head recordings in the southeastern region of Groningen allow us to calibrate our inference tool.
UK flood risk under a changing climate
Authors: Savage James , Wing Ollie , Quinn Niall , Sosa Jeison , Smith Andrew , Sampson Chris
Published: March 2022

This study presents a 30 m model of UK flood hazard that considers fluvial, pluvial and coastal sources of flooding. Each of the three sources of flooding are simulated through a hydrodynamic model utilising a number of methodologies and datasets developed in this study, including a new hydrography dataset for Great Britain, a blended Digital Terrain Model (DTM) consisting of LiDAR and open source terrain datasets and a new discharge model for Great Britain. Alongside these, the study incorporates leading datasets including sub-daily river, rainfall, tidal and sea level datasets alongside national flood defence datasets. A defence detection algorithm is also applied to identify flow control structures from high resolution LiDAR terrain data. Results from the hazard model are validated against national scale flood maps at both a building and footprint scale. Future rainfall estimates are then taken from the UK Climate Projections 18 (UKCP18) to directly estimate changes in rainfall for a number of future time horizons and climate scenarios. Hydrological models are then simulated to calculate changes in river discharge which are then used to perturb boundary conditions in the hydrodynamic model. Future estimates of sea level change are used to perturb the coastal boundary conditions. Combined, these future estimates allow us to directly model changes in UK flood risk for fluvial, pluvial and coastal flooding. We use these findings to identify parts of the UK that are expected to see the greatest changes in flood risk resulting from these future projections. 
Integrating measurement representativeness and release temporal variability to improve the Fukushima-Daiichi 137Cs source reconstruction
Authors: Dumont Le Brazidec Joffrey , Bocquet Marc , Saunier Olivier , Roustan Yelva
Published: March 2022

    The Fukushima-Daiichi accident involved massive and complex releases of radionuclides in the atmosphere. The releases assessment is a key issue and can be achieved by advanced inverse modelling techniques combined with a relevant dataset of measurements. A Bayesian inversion is particularly suitable to deal with this case. Indeed, it allows for rigorous statistical modelling and enables easy incorporation of informations of different natures into the reconstruction of the source and the associated uncertainties.
    We propose several methods to better quantify the Fukushima-Daiichi 137Cs source and the associated uncertainties. Firstly, we implement the Reversible-Jump MCMC algorithm, a sampling technique able to reconstruct the distributions of the 137Cs source magnitude together with its temporal discretisation. Secondly, we develop methods to (i) mix both air concentration and deposition measurements, and to (ii) take into account the spatial and temporal information from the air concentration measurements in the error covariance matrix determination.
    Using these methods, we obtain distributions of hourly 137Cs release rates from 11 to 24 March and assess the performance of our techniques by carrying out a model-to-data comparison. Furthermore, we demonstrate that this comparison is very sensitive to the statistical modelling of the inverse problem.
openghgmap.net -  Estimating CO2 Emissions for 108,000 European Cities
Authors: Moran Daniel , Pichler Peter-Paul , Zheng Heran , Muri Helene , Klenner Jan , Kramel Diogo , Többen Johannes , Weisz Helga , Wiedmann Thomas , Wykmans Annemie , Strømman Anders Hammer , Gurney Kevin R.
Published: March 2022

City-level CO2 emissions inventories are foundational for supporting the EU’s decarbonization goals. Inventories are essential for priority setting and for estimating impacts from the decarbonization transition. Here we present a new CO2 emissions inventory for all 116,572 municipal and local government units in Europe, containing 108,000 cities at the smallest scale used. The inventory spatially disaggregates the national reported emissions, using 9 spatialization methods to distribute the 167 line items detailed in the National Inventory Reports (NIRs) using the UNFCCC Common Reporting Framework (CRF). The novel contribution of this model is that results are provided per administrative jurisdiction at multiple administrative levels, following the region boundaries defined OpenStreetMap, using a new spatialization approach. Project website: openghgmap.net
The role of Large Igneous Provinces in controlling long-term Phanerozoic climate change
Authors: Longman Jack , Mills Benjamin J.W.
Published: March 2022

Large Igneous Provinces (LIPs) are accumulations of igneous rocks representing periods of intense volcanism in Earth’s history. The timing of the emplacement of many LIPs corresponds with global climatic perturbations and mass extinctions, leading to the hypothesis that their occurrence is implicated in these events. However, detailed investigations into these hypotheses are typically restricted to studies of individual events (e.g. the Siberian Traps emplacement at the Permian-Triassic boundary), and single forcing mechanisms (e.g. carbon emissions). As a result, it is often unclear what the overall impact of LIP emplacement was on climate in Earth’s history.

In this work, we present the results of the first integration of LIP degassing and weathering to a long-term model of global carbon cycling. We use the SCION climate-chemical model, which allows for both the addition of LIP degassing as a CO2 forcing mechanism, and the introduction of LIPs as highly weatherable terranes on the Earth surface. In this way, we can estimate both the warming impact LIPs may have had on climate change in the past, through carbon degassing, but also the cooling effect they would have had, through enhanced silicate weathering. Our work shows the importance of LIP location on weathering rates, with those which are emplaced in the mid-latitudes having the biggest cooling impact.

Comparison of our reconstruction with previous estimates of Phanerozoic climates show that the inclusion of LIPs enhances model-data comparability. This is particularly clear in the late Triassic, and Cretaceous periods, where previous model reconstructions overestimated atmospheric CO2 and global temperature. Our findings suggest LIP weathering is an important factor mitigating global climate change through the Phanerozoic.
Real-time Delivery of Sensor Data Streams using IoT and OGC Standards
Authors: Jirka Simon , Autermann Christian , Drost Sebastian
Published: March 2022

In the past, many projects have evaluated and demonstrated the use of the Sensor Web Enablement (SWE) Standards of the Open Geospatial Consortium (OGC) in order to publish sensor data. Advantages of these standards included the provision of a domain-independent approach for ensuring interoperability of interfaces, data, and metadata. However, in most cases, the developed infrastructures were limited to pull-based data retrieval patterns. This means that data consumers regularly query servers for data updates which may result in high server loads due to a high-frequency of update requests or increased latencies until a consumer receives new sensor data.

Although there were relevant specifications such as the OGC Publish/Subscribe standard as well as discussion papers, the OGC SWE framework never included a widely accepted solution to handle an active push-based delivery of observation data. With the adaptation of the SensorThings API standard of the OGC in conjunction with mainstream Internet of Things protocols such as the Message Queuing Telemetry Transport (MQTT) protocol this has changed in recent years.

In 2020 we have already presented at the EGU an approach on how to use these technologies to enable the efficient collection of sensor observation data in hydrological application by bridging between sensors and data management servers (Drost et al., 2020).

As part of this contribution, we will discuss the applicability of these technologies, OGC SensorThings API as well as MQTT, to also cover the delivery of data to consumers in addition to the previously described data transmission from sensor devices to a data sink. We will put special emphasis on experiences gathered from the deployment in marine environments (e.g., live underway data and event metadata streams of research vessels), as part of the EMODnet Ingestion II project. Special consideration will be given to a discussion of potential advantages of push-based communication patterns as well as identified challenges for future work (e.g., metadata about push-based data streams, standardization of payloads, access control, best practices on how to structure provided data streams).

Furthermore, we will address the development of data visualization tools for such interoperable real-time data streams and will discuss the opportunities to transfer these technologies to further application domains such as hydrology.

References

Drost, S., Speckamp, J., Hollmann, C., Malewski, C., Rieke, J., & Jirka, S. (2020). Internet of Things Technologies for the Efficient Collection of Hydrological Measurement Data. EGU General Assembly 2020, Online. https://doi.org/10.5194/egusphere-egu2020-10452
Combined assimilation of reanalyzed SWE and observed streamflow to enhance spring flow forecasts in southern Quebec, Canada
Authors: Farhoodi Sepehr , Leconte Robert , Trudel Mélanie
Published: March 2022

Incorporation of observed streamflow into different hydrological models has resulted in improved streamflow forecasting in many studies. This approach is currently used by different hydropower companies to maximize hydroelectric production and also to predict and mitigate flood damages. In addition, snow-related model states, such as SWE, snow depth, and snow wetness, also carry important information regarding both timing and volume of spring flow in snow-dominated regions. Consequently, the main objective of this study is to combine assimilation of observed streamflow and reanalyzed SWE to enhance spring flow forecasting. The reanalyzed SWE product investigated is SNODAS.

SNODAS is a snow data assimilation system that improves outputs of a snow model by assimilating observed snow data provided by airborne platforms, satellites, and ground stations and generates snow-related data, such as SWE and snow depth at 1 km resolution.  SNODAS is run each day so that the data product is available in near real-time.

In this study, SNODAS SWE data has been assimilated into HYDROTEL, a physically-based distributed hydrological model equipped with a snow module based on a mixed energy budget – degree-day approach, along with observed streamflow during the spring flow season in order to enhance spring flow forecasts. The study site is Au Saumon watershed, located in southern Quebec, Canada.  The Au Saumon watershed has an area of 1022  and is predominantly forested. The simulation period is the 2014-2015 water year. Preliminary results show that combined assimilation of SNODAS SWE and observed streamflow improve spring flow predictions, while SWE assimilation has a more delayed impact than streamflow assimilation.

Keywords: Data Assimilation, SNODAS, SWE, Spring Flow Prediction
Automated tool for estimating field line resonance frequencies using ground-based magnetometer measurements
Authors: Pietropaolo Ermanno , Foldes Raffaello , Del Corpo Alfredo , Vellante Massimo , Marino Raffaele
Published: March 2022

Ground-based magnetometer stations offer a valuable and easy-to-access tool for sounding the Earth’s magnetic field disturbances in the inner magnetosphere with a multi-viewpoint system. Using Ultra-Low Frequency (ULF) measurements recorded from meridional aligned stations, it is possible to infer the Field Line Resonance (FLR) frequencies, using a well-established technique, namely the gradient method (Baransky et al. 1985 and Waters et al. 1991). Based on this technique, several authors developed (semi-)automated tools for estimating FLR from ground-based magnetometer measurements. Recently it has been observed (Foldes et al., 2021) that the Machine Learning (ML) approach represents a valuable tool to estimate FLRs from Fourier cross-phase spectra. However, it is commonly known that detecting FLRs using cross-phase spectra may often be unfeasible due to data gaps, noisy signals and/or quiescent ULF wave periods. To handle these situations, we implement an ML classification algorithm to detect periods in which resonance frequencies are clearly observable and thus can be easily estimated. Our algorithm can distinguish between periods with observed frequency from the others; moreover, it can determine if the considered field line is crossing the plasma boundary layer (PBL) at a given time. The results of our method are validated for a particular pair of stations (at L=2.9), along the Equatorial quasi-Meridional Magnetometer Array (EMMA), which provides an extensive data set with several different geomagnetic conditions. This kind of approach in the analysis of ground-based magnetic field measurements, combined in a two-stage ML pipeline with a regression algorithm (as in Foldes et al., 2021), may provide a prominent tool for monitoring the plasmasphere dynamics using a completely automated system.
Mirror mode-like structures around unmagnetised planets: a comparison between the magnetosheaths of Mars and Venus
Authors: Simon Wedlund Cyril , Volwerk Martin , Mazelle Christian , Rojas Mata Sebastián , Stenberg Wieser Gabriella , Mautner David , Halekas Jasper , Espley Jared , Rojas-Castillo Diana , Möstl Christian , Bertucci César
Published: March 2022

Mirror mode structures arise whenever a temperature anisotropy is present in the plasma, classically in the wake of the bow shock in a quasi-perpendicular configuration with respect to the interplanetary magnetic field, or from pickup ion distribution effects. Born from space plasma instabilities and in competition with other wave modes, these ultra-low frequency waves contribute to energy exchanges between the different plasma populations present in the magnetosheath. At Mars and Venus, such structures have very similar scales: they last typically a few tens of seconds and appear as peaks or dips in the magnetic field data in antiphase with the local plasma density variations. As magnetometers are present on many space missions, magnetic field-only criteria are an ideal tool to study these structures across different magnetosheath environments. We present here for the first time a comparison of the statistical occurrence of magnetosheath mirror mode-like structures at Mars with MAVEN and at Venus with Venus Express. Based on magnetic field-only measurements, we use identical detection criteria at both planets to select quasi-linear structures in B-field measurements. We then present two-dimensional maps of mirror mode-like occurrence rates with respect to solar cycle variations and EUV flux levels, atmospheric seasons (for Mars) and the nature of the shock crossing (quasi-parallel or quasi-perpendicular configurations), and compare them between planets. Finally, we discuss ambiguities in the nature of the detected structures and their global effects on the magnetosheath.
Century scale CO2 pulses could substantially alter marine primary production, CaCO3 export, oxygen concentrations and DMS emissions
Authors: Liebermann Ralf , Hofmann Matthias
Published: March 2022

The world's oceans have historically made a significant contribution in mitigating global warming by storing both large amounts of anthropogenic CO2 emissions and a significant portion of the heat generated by the enhanced greenhouse effect. However, precisely because of this buffering function, they are themselves subject to massive chemical and physical regime shifts that are suspected to continue long after anthropogenic CO2 emissions have ceased. For this reason, within the HORIZON2020-COMFORT project, we are studying the long-term effects that different scenarios of temporarily increasing atmospheric CO2 concentrations could have on marine biogeochemistry. To this end, we use CLIMBER3alpha+C, an Earth system model of intermediate complexity, to study the response of the ocean carbon cycle and associated nutrients during and after the period of elevated atmospheric pCO2 levels. Preliminary results show sustained changes in marine primary production, export of CaCO3, extent of hypoxic zones and production of dimethyl sulfide (DMS), with DMS acting as a condensation nucleus in cloud formation. This raises the possibility that the effects of elevated CO2 on the oceans will cause a change in both the Earth's radiative balance and the marine carbon pump long after atmospheric CO2 concentrations have returned to preindustrial levels.

 

 

Acknowledgements:

“This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 820989 (project COMFORT, Our common future ocean in the Earth system – quantifying coupled cycles of carbon, oxygen, and nutrients for determining and achieving safe operating spaces with respect to tipping points).”

 

Disclaimer:

“This [project/poster/presentation/etc.], reflects only the author’s/authors’ view; the European Commission and their executive agency are not responsible for any use that may be made of the information the work contains.”

 
Solutions for existing and future challenges in water governance
Authors: Nakulopa Faluku , Borchardt Dietrich , Marcé Rafael , Rinke Karsten , Bärlund Ilona
Published: March 2022

Global surface water bodies suffer multitude of human induced pressures that lead to the deterioration of water status through conditions of anoxia, eutrophication, pollution, depletion, among others, which compound water scarcity. Climatic and socio-economic changes will most likely exacerbate the water crises. However, effective water governance strategies can be deployed to mitigate water crisis and guarantee sustainable water use and ecosystem health.  Such strategies can be developed and implemented using a holistic modelling approach.  In this study, we aim at developing – through re-analysis and modelling – an adaptive water governance framework that can be utilized to ensure sustainable water-use and ecosystem health. The study will be piloted at the Möhne reservoir in the North Rhine-Westphalia state, Germany – representing a multi-decadal time machine for hydroclimatic changes, socioeconomic dynamics and water governance by the Ruhrverband. The study will address five key questions; i) How did the drivers and pressures of the reservoir water status change over time? ii) How did the water governance structures change/respond over time? iii) How did the water quality and quantity change over time? iv) What are the likely future drivers, pressures and governance structures/responses? v) Are there strategies to compare with or transfer to/from other systems?

In order to reconstruct the drivers, pressures, status and impacts of the Möhne reservoir waters, with the respective management and policy responses over time, we start by re-analyzing the multi-decadal trajectory of a few representative variables. In this poster we highlight this using air temperature and precipitation, reservoir water level and population changes in the catchment.
Modeling Potential Impacts of Gas Exploitation on the Israeli Marine Ecosystem Using Ecopath with Ecosim
Authors: Lahav Ella , Astrahan Peleg , Ofir Eyal , Gal Gideon , Bookman Revital
Published: March 2022

Exploration, production, extraction and transport of fossil fuels in the marine environment are accompanied by an inherent risk to the surrounding ecosystems as a result of the on-going operations or due to technical faults, accidents or geo-hazards. Limited work has been conducted on potential impacts on the Mediterranean marine ecosystem due to the lack of information on organism responses to hydrocarbon pollution. In this study, we used the Ecopath with Ecosim (EwE) modeling software which is designed for policy evaluation and provides assessments of impacts of various stressors on an ecosystem. An existing EwE based Ecospace food-web model of the Israeli Exclusive Economic Zone (EEZ) was enhanced to include local organism response curves to various levels of contaminants, such as crude oil, in the water and on the sea floor sediments. The goal of this study is to evaluate and quantify the possible ecological impacts of pollution events that might occur due to fossil fuel exploitation related activities. Multiple spatial static and dynamic scenarios, describing various pollution quantities and a range of habitats and locations were constructed. Using the enhanced Ecospace models for assessing the potential impacts of gas exploitation on organism biomass, the spatial and temporal distribution and food-web functioning was tested and evaluated. The results of this study will show a quantitative assessment of the expected ecological impacts that could assist decision makers in developing management and conservation strategies.
The state-of-the-art in cave ice coring
Authors: Kern Zoltán , Perșoiu Aurel
Published: March 2022

Since the first core drilled in a cave ice deposit in 1947, more than 141 m of ice cores has been extracted from 20 cave ice deposits worldwide until 2021. Cave ice drilling projects focused mainly in Central European caves, however, half of the cave ice cores (3 out of 6) published in 2020 represent non-European localities predicts that an increasing number of such projects are focusing on other geographical areas hosting ice caves. Depending on the two types of ice encountered (firnified snow and frozen water), local climatic conditions and cave geometry, cave ice cores have highly variable length (between 1 and 25 m long), time span and continuity of the record covered (from a few years up to several thousands of year). The longest cave ice core in terms of both core length (~25 m) and continuous time span (~10 kyr) comes from Scărișoara Ice Cave (Romania), with several others (in Spain, Slovakia, Austria, Romania, the USA) reaching back in time towards (and beyond) the mid-Holocene. Major challenges in cave ice core science are posed by 1) presence of englacial rocky and woody debris, 2) complex stratigraphy of the ice deposits (often disturbed due to ice flow in a restricted space), 3) problematic chronology and 4) complex mechanisms of climate-proxy information transfer. Regardless, cave ice deposits offered over the past decade several unique records of Holocene climate and environmental change as well as of past microbial and fungal diversity. Because ice caves are located at much lower altitudes and latitudes than polar and mountain glaciers, they face the double threat of both increasing temperatures and precipitation amounts, several possible milennial old deposits being lost over the past few years. An ongoing race to salvage the paleoclimatic information these ice deposits holds is thwarted by climatic, financial and knowledge risks.
Frequency-dependent Ganymede’s tidal Love number k2 detection by JUICE’s 3GM experiment and implications regarding the subsurface ocean characterization
Authors: De Marchi Fabrizio , Cappuccio Paolo , Mitri Giuseppe , Iess Luciano
Published: March 2022

Ganymede will be the first icy satellite orbited by a spacecraft: ESA's JUpiter ICy moons Explorer (JUICE). The launch is scheduled for September 2022 and the arrival at Ganymede is foreseen in 2035.

Precise range and range-rate data (Ka-band) will be provided by the tracking system of the onboard Geodesy and Geophysics of Jupiter and Galilean Moons experiment (3GM).

These measurements will be used to infer, among others, the static gravity field of the moon up to degree 35-45.

Tidal stresses generate the time-varying part of the Ganymede’s gravitational field and the largest contribution is due to the interaction with Jupiter, modulated by the eccentricity of the Ganymede’s orbit.

However, our work is focused on the lower amplitude time-varying components: those generated by the tidal interactions with Io, Europa and Callisto.

To a good approximation, the corresponding gravitational signals are periodic functions composed by several harmonics of the fundamental synodic frequencies Io-Ganymede, Europa-Ganymede and Ganymede-Callisto. The elastic response of Ganymede is expected to be frequency-dependent as well.

Therefore, we modeled Ganymede’s k2 as a set of coefficients, one for each frequency, to be estimated.

In this work we describe a procedure, supported by numerical simulations and a covariance analysis, to estimate these coefficients in the standard orbit determination framework of the 3GM experiment during the orbital phase at Ganymede.

Finally, we show how the measured coefficients and their accuracies, supported by a viscoelastic model of Ganymede, can be used to provide constraints on the outer ice shell thickness, and on the subsurface ocean density and thickness.
Comparison of wind measurements from different Doppler lidar scan strategies and two lidar brands with an ultrasonic anemometer
Authors: Wolz Kevin , Wildmann Norman , Beyrich Frank , Päschke Eileen , Detring Carola , Mauder Matthias
Published: March 2022

Technology has reached a point where ground-based remote sensing instruments have the ability to greatly increase the spatial and temporal data density compared to conventional instruments. This offers the great opportunity to improve the understanding of individual processes and to increase the predictive capabilities of numerical weather models and reduce their inaccuracies. The goal of this study is to assess these measurement inaccuracies and the usefulness of Doppler lidar systems for these purposes. The data were collected during the FESST@MOL 2020 measurement campaign, organised by the German Weather Service (DWD) and initiated by the Hans-Ertel-Center for Weather Research (HErZ), at the boundary layer field site (GM) of the DWD in Falkenberg (Tauche), Germany. During the measurement campaign, a total of eight Doppler lidars of the brands Halo Photonics and Leosphere were active in different operating modes. We compare the results of triple and single Halo Photonics lidar setups and triple Leosphere lidar setups with the measurements of an ultrasonic anemometer mounted at a height of 90 m at the 99 m high instrumented tower in Falkenberg. The focus of the operating modes was on various virtual tower (VT) measurements and velocity azimuth display (VAD) measurements with the different averaging times of ten and thirty minutes for the mean horizontal wind. The discrepancy in readings between VT and VAD measurements increases with increasing height above the ground while the Halo Photonic lidars performed better in the comparison with the sonic anemometer.
Hydrogen isotopes in assimilates and cellulose, but not in n-alkanes, integrate signals of the plant primary carbon metabolism
Authors: Lehmann Marco M. , Schuler Philipp , Cormier Marc-André , Ghiasi Shiva , Werner Roland A. , Saurer Matthias , Wiesenberg Guido
Published: March 2022

Recent studies suggest that isotope ratios of the carbon-bound non-exchangeable hydrogen (δ2H) in plant cellulose and lipids can indicate changes in the primary carbon and energy metabolism; however, systematic investigations are scarce.

Here, we studied δ2H patterns in two different tobacco (N. sylvestris) model systems, where severe changes in the plant primary metabolism were known: 1) along a nitrogen (N) supply gradient and 2) in a starch-less knockout mutant (pgm). Specifically, we measured δ2H of water, bulk soluble sugars, transitory starch, and cellulose in leaves and roots, using a novel hot water vapor equilibration method and TC/EA-IRMS. Besides, we measured δ2H values of leaf n-alkanes with GC-IRMS.

We observed clear δ2H differences in sugars and starch along the N gradient and a 2H-enrichment of both assimilates in pgm compared to a wild type control. The photosynthetic 2H-fractionation between leaf water and sugars/starch reached a maximum of ca. 100‰ in both model systems and was related to changes in concentrations of primary metabolites (e.g. sugars, starch, organic and amino acids), enzymatic activities, gas-exchange, and growth. The signal of the primary carbon metabolism was also visible in δ2H of leaf and root cellulose in both system, but dampened compared to those of sugars and starch. In contrast, the signal was absent in leaf n-alkanes in both systems.

Our results provide the first direct evidence that changes in the primary leaf carbon metabolism are imprinted on δ2H of plant carbohydrates in leaf and roots. The metabolic signal might therefore be reconstructed from plant material of important paleo archives (e.g. tree-ring cellulose, lake sediments) and help to better understand plant-climate interactions. The absence of the signal in δ2H of leaf n-alkanes is surprising and suggests a strong difference in metabolic fluxes between carbohydrates and lipids. Yet, this observation may help to further disentangle the processes shaping hydrogen isotopes in plants.
Managing multi-layered geographic information to describe environmental monitoring and research sites using DEIMS-SDR
Authors: Wohner Christoph , Peterseil Johannes
Published: March 2022

Providing information on the context of long-term measurements, i.e. the observation and research facilities where measurements were done, is key for re-using data generated for a defined area. This information is also needed to manage site networks of research infrastructures or research networks or to enable a link from in-situ measurements to earth observation. To cover these requirements, the Dynamic Ecological Information Management System – Site and Dataset Registry (DEIMS-SDR, https://www.deims.org/) allows the description of in-situ environmental observation or experimental sites implementing a multipurpose data model and generating persistent, unique and resolvable identifiers for each site. The aim of DEIMS-SDR is to collect site information in a catalogue describing a wide range of sites across the globe, providing information including each site's location, ecosystems, facilities, measured parameters and research themes and enabling that standardised information to be openly available. DEIMS-SDR currently stores over 1200 site records along a wide geographic, altitudinal and ecosystem gradient. To address research needs as well as to enhance interoperability and machine readability, the used site model has been revised and compared to existing de-facto standards resulting in a more modular structure.

The presentation describes the outcomes of the revision of the data model, the conceptual considerations behind it and how it is implemented. We illustrate the capabilities of the data model focussing on the description of multi-layered geographic information that is needed to accurately document sites and the various observation locations they might cover. This represents a major step forward in both the development of DEIMS-SDR as well as the interoperable and cross-disciplinary documentation of sites in general.