bluuebunny/crossref_metadata_2025 huggingface dataset:
First evaluation of a 6-months Meteodrone campaign
Authors: Hervo Maxime , Pasquier Julie , Hammerschmidt Lukas , Weusthoff Tanja , Fengler Martin , Haefele Alexander
Published: February 2023

 From December 2021 to May 2022, MeteoSwiss conducted a proof of concept with Meteomatics to demonstrate the capability of drones to provide data of sufficient quality and reliability on a routine operational basis. Meteodrones MM-670 were operated automatically 8 times per night at Payerne, Switzerland. 864 meteorological profiles were measured and compared to co-localized measurements including radiosoundings and remote-sensing instruments. To our knowledge, it is the first time that Meteodrone measurements are evaluated in such an intensive campaign.The availability of the Meteodrone measurements over the whole campaign was 75.7% with 82.2% of the flights reaching the nominal altitude of 2000m above sea level. Using the radiosondes as a reference, the quality of the Meteodrone measurements can be quantified according to WMO requirements (WMO OSCAR , 2022). Applying this method, the temperature measured by the Meteodrone can be considered as a “breakthrough”, meaning that they are a significant improvement if they are used for high resolution Numerical Weather Prediction. The Meteodrone’s humidity and wind profiles are classified as “useful” for high-resolution numerical weather predictions, suggesting they can be used for assimilation in numerical models. The quality is similar compared to the temperature measured by a microwave radiometer and the humidity measured by a Raman Lidar. However, the wind measured by a Doppler Lidar was more accurate than the estimation of the Meteodrone.This campaign opens the door for operational usage of automatic drones for meteorological applications.
Rheology of bubble-bearing magma suspensions under unsteady flow conditions
Authors: Frontoni Alessandro , Vona Alessandro , Romano Claudia
Published: February 2023

The eruptive style of a volcanic system and the energy of the eruption depend on a complex interplay among several internal and external factors, as temperature, pressure, volatile composition and content, and geometry of the volcanic system, all of which concur to affect the rheology of the magma and thus the eruptive strength of a volcano.The comprehension of the rheological behavior of the mixtures of melt, crystals, and bubbles is necessary to understand the migration of magma within the volcanic system and the modality of eruptions. To date, crystal-bearing magmas and their behavior have been the focus of the majority of investigations by the scientific community.The paucity of studies on bubble-bearing magmas may have been partly due to the greater challenges posed by the experimental procedure, mostly related to the outgassing of the gas phase during the experiments. So, while the influence of crystals in magma rheology has been parameterized in detail, a comprehensive model for the rheology of the bubble-bearing magmas has yet to be formulated.The aim of this work is to understand the complex dependence of the viscosity on the bubble content and strain rate, by performing suites of in situ degassing experiments on rhyolitic magma at an experimental temperature of 850 °C, followed by uniaxial deformational experiments (constant strain rates of 5 x 10-5, 10-4 and 10-3 s-1) through a vertical uniaxial press at experimental temperatures varying between 720 and 800 °C. Experimental parameters are selected to investigate the rheology under unsteady flow conditions (i.e., prior to equilibrium deformation of bubbles). Such conditions may be very common during explosive volcanic eruptions, where bubbles are not able to relax in the fast-ascending magmas.For constant strain rates, results show trends of apparent viscosity as a function of bubble content, consisting of an initial increase of viscosity for low amounts of bubbles (0-20%), followed, above the 20% threshold porosity, by a general viscosity decrease. At fixed porosity, a strain rate dependence of viscosity is also observed, with viscosity decreasing as the strain rate increases. Overall, the sample's apparent viscosity appears to be non-linearly controlled by both ambient conditions (Temperature Tdef and Strain rate ) and sample texture (Porosity and Vesicle Number Density VND), whose interplay concurs to define the degree of flow unsteadiness. We, therefore, discuss the weight of each parameter in determining the apparent viscosity of the magmatic mixture.
A set of deterministic and stochastic model improvements for the AWI-CM3 climate model
Authors: Streffing Jan , Semmler Tido , Sidorenko Dmitry , Pithan Felix , Juricke Stephan
Published: February 2023

We present intermediate results as well as ongoing work on improving the post-CMIP6 climate model of the Alfred Wegener Institute, AWI-CM3. A baseline version of the model was completed in 2021 with an above average performance when compared to other CMIP6 models. Close investigation of surfaces fluxes revealed that v3.0 can be further improved in a number of ways which will also benefit other climate models.As a first step we reevaluated old coupling simplifications and assumptions made years ago. At the air-sea ice interface we corrected the gradient of surface sensible heat flux / wind speed vs. (2m air temp - sea ice surf temp), by using a nudged version of AWI-CM3 and evaluating against in situ data from the MOSAiC-Expedition. We added the coupling of ocean current feedback, as well as new latent and sensible heat fluxes resulting from precipitation entering the ocean with a different temperature and state than the ocean surface. As a precursor to subsequent Earth System Model (ESM) development we included the coupling of mass and heat fluxes of snow falling on ice-sheets. The resulting AWI-CM3 v3.1 shows increased ability to represent the current climate and historic climate change.Furthermore we present ongoing work towards AWI-CM3 v3.2, where among other improvements we will include the coupling of sub atmospheric gridscale information from the higher resolution ocean grid, via a stochastic method. Finally we give a brief outlook on our efforts to link up with the EC-Earth climate and earth system model community for common cryosphere, vegetation and isotope developments towards two comprehensive ESMs.
UAS-SfM-derived Elevation Models to Evaluate Changes in the Flow Accumulation and Wetness in Minerotrophic Peatland Restoration Monitoring
Authors: Ikkala Lauri , Ronkanen Anna-Kaisa , Ilmonen Jari , Similä Maarit , Rehell Sakari , Kumpula Timo , Päkkilä Lassi , Kløve Bjørn , Marttila Hannu
Published: February 2023

Most northern peatlands are severely degraded by land use and drainage. Peatland restoration is an effective way to return the natural functions of peatlands in the catchment hydrology, discontinue the peat degradation and re-establish the long-term carbon sinks. The main aim of the rewetting is to direct the water flows back to the pristine routes and to increase the water-table levels. Conventional monitoring methods such as stand-pipe wells are typically limited to sparse locations and cannot give a spatially representative overview.We introduced a novel high-resolution approach to spatially evaluate the surface flow path and wetness changes after restoration. We applied a UAS SfM (Unmanned Aerial System Structure-from-Motion) method supported by ubiquitous LiDAR (Light Detection and Ranging) data to produce digital elevation models, flow accumulation maps and SWI (SAGA Wetness Index) models for two boreal, minerotrophic restoration sites and their pristine control sites. The pristine sites were to represent natural changes and technology-related uncertainty.According to our results, the hydrological restoration succeeded at the sites showing that the wetness increased by 2.9–6.9% and its deviation decreased by 13–15% 1–10 months after the restoration. Absolute changes derived with data from simultaneous control flights at the pristine sites were 0.4–2.4% for wetness and 3.1–3.6% for the deviation. Also, restoration increased the total length of the main flow routes by 25–37% while the controlling absolute change was 3.1–8.1%.The validity of the topography-derived wetness was tested with field-gathered soil moisture samples which showed a statistically significant correlation (R2 = 0.26–0.42) for the restoration sites but not for the control sites. We conclude the water accumulation modelling based on topographical data potential for assessing the changed surface flows in peatland restoration monitoring. However, the uncertainties related to the heterogenic soil properties and complex groundwater interactions require further method development.
Remote SO2 flux by UV and TIR ground based cameras at Sabancaya volcano (Peru), cross comparison and validation with satellite data
Authors: Corradini Stefano , Salerno Giuseppe , Campion Robin , Guerrieri Lorenzo , Merucci Luca , Stelitano Dario
Published: February 2023

During the 14th IAVCEI Field Workshop held in Peru from 6 to 14 November 2022, SO2 plume measurements were carried out remotely in the volcanic plume of Sabancaya volcano. Sabancaya is an active stratovolcano located in southern Peru (15.787°S, 71.857°W), Sabancaya’s first historical record of an eruption dates to 1750 and the most recent eruption began in November 2016. Volcanic activity consist of rhythm vulcanian explosions, which produce a gas-ash rich plumes which rose few km above the summit terrace. On 10 and 11 November 2022, side-by-side observation by UV and TIR ground-based cameras were remotely carried out with the object to observe the passive and active SO2 burden from the volcanic plume of Sambacaya. Two UV cameras systems were employed observing the volcanic plume at 2- and 5-seconds time steps and calibrating SO2 amounts by coupling SO2 DOAS inverted column densities ad and SO2-quartz cell amounts. The TIR camera (named VIRSO2) is a novel system developed for the detection of volcanic plumes, the estimation of the height and the determination of columnar content and the SO2 flux. It allows acquisition of high frequency data both during the day and at night. It is equipped with 3 cameras, two broadband TIR (7-14 micron) and a VIS, capable of acquiring data simultaneously. For the quantitative estimation of SO2, an 8.7 μm filter is installed in front of one of the TIR camera. Retrieved cameras products were cross-compared and validated in order to determinate limit an uncertainty of both methods and results were also compared with those obtained by S5p-TROPOMI instrument.Preliminary results show a feasible strength between the three ground and space-based techniques. Within the uncertainties of each method, differences between inverted SO2 column densities and emission rates arise from field of view geometrical sampling set-up and radiative transfer. Results gathered in this study prove the promising application of ground-based TIR in volcanic plume SO2 observation.
Qatar Peninsula's vulnerability to oil spills and its implications for the global gas supply
Authors: Hanert Emmanuel , Heggy Essam , Dobbelaere Thomas , Anselain Thomas
Published: February 2023

More than 20% of global liquefied natural gas (LNG) exports and almost all of Qatar’s drinking water production originate from three industrial sites within a few tens of kilometers on the eastern coast of Qatar’s peninsula. However, with the observed regional increase in maritime transport accidents, the vulnerability of those sites to major oil spills remains largely unquantified, let alone understood, due to complexities in forecasting and containing pollution in such shallow waters and harsh hyper-arid environments. To address this deficiency, we model the oil spill dispersal in the shallow maritime waters surrounding Qatar’s peninsula to identify which offshore areas and times of the year pose the most significant threat to both LNG export and seawater desalination facilities. By combining the outcome of our oil transport simulations with marine traffic data, we identify two high-risk areas, sizing up to ~15% of Qatar’s maritime exclusive economic zone, where the elevated oil pollution exposure is concentrated and can cause major disruptions to the above facilities. Our results suggest that the major LNG liquefaction terminal of Ras Laffan has the highest vulnerability to oil spills among all studied sites all year long. Moreover, the desalination plant to the North of Ras Laffan, producing 30% of the national water supply, has a seasonal vulnerability peaking up to an alarming level twice a year during spring and fall. The two other desalination plants located southeast of the peninsula have a lower vulnerability all year long. Furthermore, both LNG export and desalination facilities are found to be highly vulnerable to oil spills occurring outside of Qatar’s maritime borders, which could land in these vital infrastructures in less than two days. These delays are further reduced when considering the spill's arrival time near coastal waters shallower than 5 m depth, which are inaccessible to several large containment vessels. Therefore, we suggest that those two offshore high-risk areas be closely monitored with airborne and orbital SAR observations, providing early warning for oil spills that can severely disrupt the LNG exports from Ras Laffan, further aggravating the global gas crisis.Reference:Anselain T., E. Heggy, T. Dobbbelaere and E. Hanert (2023) Qatar Peninsula’s vulnerability to oil spills and its implications for the global gas supply, Nature Sustainability, in press, https://www.nature.com/articles/s41893-022-01037-w 
Smart IoT sensors as part of a holistic solution for improving resilience and sustainable reconstruction of historic areas
Authors: Kalis Dr. Antonis , Mitro Nikos , Amditis Dr. Angelos
Published: February 2023

Although Climate Change (CC) has already been reported to have a significant impact on historical areas hosting Cultural Heritage (CH) sites, it is still challenging to assess quantitatively and qualitatively the impact of various climatic and other parameters on the CH sites, since the specific climatic conditions at their vicinity, and the emanating effects on their structure, are difficult to grasp due to cost and regulatory barriers. In the framework of the HYPERION EU project, we address this problem by providing a holistic solution for improving resilience and sustainable reconstruction of historic areas, which integrates the use of smart IoT devices, called Smart Tags, designed to provide environmental measurements close to monuments, with a number of state-of-the-art of technologies, services and tools (e.g. advanced ML, IoT, satellite and terrestrial imaging, social networking, event, material decay and business continuity modelling), in order to develop a single decision support system which aspires to become the cornerstone for resilience and reconstruction planning for historic areas in the future.
Accretion of fast-spreading oceanic crust: benefits from large-scale sampling in the Oman ophiolite in combination with cores drilled by the ICDP Oman Drilling Project
Authors: Koepke Jürgen , Garbe-Schönberg Dieter , Mock Dominik , Merseburger Sven
Published: February 2023

Based on a newly established profile through fast-spreading oceanic crust of the Oman ophiolite and on cores drilled within the ICDP Oman Drilling Project (OmanDP), we present here the results of 12 years research, focusing on the nature of the magmatic accretion of the deep crust beneath fast-spreading mid-ocean ridges. We established a 5 km long profile through the whole plutonic crust of the Oman ophiolite by systematic outcrop sampling in the Wadi Gideah (Wadi Tayin Block near Ibra), providing the reference frame for the 300 to 400 m long OmanDP drill cores GT1 and GT2 (lower crust, mid-crust), as well as CM1 and CM2 (crust-mantle boundary) drilled into the same area.The results allow implication on the mechanism of accretion of fast-spreading lower oceanic crust. Depth profiles on bulk rock and mineral compositions, crystallization temperature and microstructures combined with petrological modeling reveal insights into the mode of magmatic formation of fast-spreading lower oceanic crust, implying a hybrid accretion mechanism. The lower 2/3 of the crust (mainly layered gabbros) was formed via the injection of melt sills and in situ crystallization. Here, upward moving fractionated melts mixed with more primitive melts through melt replenishments, resulting in an upward differentiation trend. Since the fraction of crystallization is only small, upmoving melts could easily transport the latent heat produced by deep crystallization upward. The upper third of the gabbroic crust is significantly more differentiated, in accord with a model of downward differentiation of a parental melt originated from the axial melt lens sandwiched between the gabbroic crust and the sheeted dike complex. While the 5 km long profile shed light on the overall magmatic accretion process, the Oman DP drill cores showing ~ 100% recovery allowing high density sampling provide incredible details on the magmatic accretion process. Examples are the identification of individual melt sills from which the layered gabbro section has been formed (drill core GT1) or the detailed observation of olivine accumulation at the base of the crust (drill cores CM1/CM2).
A new UV-Oxidation set up for AMS radiocarbon analysis for small dissolved organic carbon in marine and fresh water samples
Authors: Haghipour Negar , Lupker Maarten , Wacker Lukas , White Margot , Bröder Lisa , Eglinton Timothy I.
Published: February 2023

Radiocarbon measurements of dissolved organic carbon (DOC) can give us valuable information about origin and age of DOC, a major, yet little understood component in the global carbon cycle. One way to measure DOC in water is to remove dissolved inorganic carbon first, oxidize organic carbon with UV irradiation and ultimately analyses the formed inorganic CO2 for 14C. The main challenge of UV-Oxidation (UVox) methods is to extract the typically low concentrations of DOC with low blanks required for relatively high precision 14C measurements. A disadvantage of currently used UVox methods is that only one sample can be oxidized in a laborious process at the same time in large volume. Here we present a UV-Oxidation system where up to 12 water samples can be oxidized simultaneously in 12 separate quartz reactors arranged around a single UV lamp in a compact setup. The simple setup further uses helium instead of vacuum typically used by conventional extraction lines to speed up the extraction of the formed CO2 after oxidation. The key improvements of the new UVox setup are: 1) Reduced amount of water needed (30- 60 ml) as samples are measured for 14C with the Micadas gas ion source., 2) UV oxidation efficiency for standards is high (96%), 3) No KI trap is needed, 4) Required time for sample preparation of up to 12 samples is 4-6 h, 5) combined the CO2 from different reactors to one trap.  We obtained 2.6 ± 0.6 µgC with F14C= 0.27±0.05 for processing blank.  We will present the first measurments of DOC samples from Swiss lakes, Canadian Beaufort Sea and the reproducibility of the line.
A comparison between investment in hydraulic infrastructures and the consequent risk reduction: a case study in Italy
Authors: D Ayala Margherita , Arosio Marcello , Martina Mario
Published: February 2023

Flooding constitutes the most frequent and one of the most destructive natural disasters, and every year it affects millions of people worldwide causing loss of life, disruption of many essential services. Even in Italy, floods represent one of the most widespread extreme events, increasingly common and hazardous.Due to the big discrepancy, highlighted in an Italian recent report, between funds spent before and after the occurrence of a flood event, respectively for risk prevention and for recovery, it is of major interest understanding where money is spent both from a geographical perspective and from a risk level area point of view.Through a deep analysis on the economic and technical criteria used to design infrastructures for flood risk protection, based on the Italian ReNDiS database (Repertorio Nazionale degli interventi per la Difesa del Suolo – National Database of soil protection measures) a comparison between type of hydraulic infrastructures and their cost, and official risk maps produced in accordance with the EU flood Directive (2007/60/EC) have been done.Moreover, this work also aims to understand if the current criteria with which flood risk maps are produced catch the effects in terms of benefit of the flood risk mitigation measures.The authors want to prove the importance of a risk-based design for mitigation measures instead of a simple application of the current legislation that does not catch all the components of the risk.
Uncovering the Slope Water Dynamics in the Layered Subsurface of Saprolite Dominated Landscapes: A Case Study from the Bavarian Forest, Germany
Authors: Zhuang Yuan , Putzhammer Sarah , Holmer Anna , van Grinsven Sigrid , Völkel Jörg
Published: February 2023

In the low and mid-mountain ranges of Central Europe, such as the vast Bavarian Forest, slopes are dominated by quaternary stratified Periglacial Slope Deposits (PSD), often underlain by saprolite. Previous research already pointed out that both PSDs and saprolite significantly impact the slope water movement and storage. In this study, in addition to slope water movement and intermediate storage in PSDs and saprolite, we investigate the transition to the active floodplain and the stream itself. From a geomorphological and pedological point of view, another focus is on the role of saprolite and loess, far outside the classic loess distribution areas.The study area 20 km North of the City of Regensburg encompasses two catenae, each showing an upper slope planted with forest, a middle and toe slope covered with grassland, transitioning into a river floodplain that is also gras covered. The geomorphogenesis, soil genesis, and soil properties of these slopes are to be discussed as an essential basis for the work. Besides physicochemical analysis to characterize sediment and soil properties, also numerical dating techniques (OSL) are used. Furthermore, we use geophysical methods like ERT, SSR, and GPR to prospect the architecture of the shallow subsurface along the entire hillslope. Finally, we permanently instrumented each catena with, among other things, soil moisture probes and tensiometers. These are placed based on the position of particular sediment layers like PSDs, to highlight their differentiation and role in the slope water transport. The aim is to develop a model of the shallow subsurface, characterizing the pathways and temporary buffer of slope water under the given geomorphological conditions.
The influence of physical properties of crustal rocks on volcanic unrest at Campi Flegrei caldera
Authors: Buono Gianmarco , Caliro Stefano , Chiodini Giovanni , Giudicepietro Flora , Maccaferri Francesco , Macedonio Giovanni , Pappalardo Lucia , Pozzi Giacomo , Spagnuolo Elena , Tramelli Anna
Published: February 2023

The Campi Flegrei caldera is in an unrest phase, manifested by increasing ground uplift, seismicity and hydrothermal activity since 2005. The seismicity mainly involves the first 3 km below the main hydrothermal site of Solfatara-Pisciarelli, where an intensifying heating and pressurization phase is inferred by gas geothermobarometers. Geodetic data inversions generally localize the deformation source around this depth in the central sector of the caldera. Two driving mechanisms of magmatic and non-magmatic unrest have been proposed. Recent studies have demonstrated that the main magma storage area is localized at a depth of ~8 km and is periodically recharged by a mafic deeper source. Magmatic fluid transfer from these reservoirs toward the surface can occur through small-volume shallow intrusions, and can occasionally culminate in an eruption. In this frame, investigating the physical properties of subsurface rocks can be valuable to define the source of the current and past unrest. In fact, they can largely affect local stress and strength, controlling volcano dynamics. We explored subsurface rocks of the Campi Flegrei caldera, extracted from 3-km-deep exploratory geothermal wells. X-ray microtomography investigations were combined with in-situ mechanical experiments (4D imaging at room temperature and dry conditions) to characterize rock properties and link them with 3D microstructural changes. The cores were collected according to the most representative stratigraphic levels and are dominated by tuffs alternating with minor lavas. The mineralogical assemblage reflects different depth-dependent T-P conditions ranging from argillic alteration (150 °C) to thermometamorphism (350 °C). Their tensile strength varies between 2 and 15 MPa and shows a general increase with depth, suggesting that a similar excess pressure is required within a potential shallow chamber to drive magma transfer. Combining this preliminary data with correspondent elastic properties, it can be inferred that a volume change between 0.001 and 1 km3 is sufficient to cause rupture conditions in a sill with radius between 0.5 and 5 km, respectively. These results are in agreement with magma volumes erupted during past eruptions at Campi Flegrei caldera, and particularly consistent with volcanological and petrological data of products from small-scale events.
A perfect model study on the reliability of the added small-scale information in regional climate change projections
Authors: Lenderink Geert , de Vries Hylke , van Meijgaard Erik , van der Wiel Karin , Selten Frank
Published: February 2023

The issue of the added value (AV) of high resolution regional climate models is complex and still strongly debated. Here, we approach AV in a perfect model framework within a 16-member single model initial condition ensemble with the regional climate model RACMO2 embedded in the global climate model EC-Earth2.3.  In addition, we also used an ensemble produced by a pseudo global warming (PGW) approach. Results for winter temperature and precipitation are investigated from two different perspectives: i) a signal-to-noise perspective analysing the systematic response to changing emission forcings versus internal climate variability, and ii) a prediction perspective aimed at predicting a 30-year future climate state. Systematic changes in winter temperature and precipitation contain fine-scale response patterns, but in particular for precipitation these patterns are small compared to internal variability.  Therefore, single members of the ensemble provide only limited information on these systematic patterns. However, they can be estimated more reliably from PGW members because of the stronger constraints on internal variability. From the prediction perspective, we analysed AV of fine-scale information by comparing three prediction pairs. This analysis shows that there is AV in the fine-scale information for temperature, yet for precipitation adding fine-scale changes generally deteriorates the predictions. Using only the large-scale change (without fine scales) from a single ensemble member as a delta change on top of the present-day climate state, already provides a robust estimate of the future climate state and therefore can be used as a simple benchmark to measure added value.
How UAV improve past metallurgical deposits characterization for landfill regeneration
Authors: Michel Hadrien , Dumont Marc , Caterina David , Jonard François , Isunza Manrique Itzel , Debouny Tom , Nguyen Frédéric
Published: February 2023

Ancient metallurgical industries produced large amounts of residues, which were typically deposited in heaps or tailing ponds. The presence of such wastes could represent a potential source of pollution that may prevent the reuse of the sites. The NWE-REGENERATIS project aims to characterize different types of metallurgical deposits in order to improve their management and rehabilitation. The understanding of these sites is made difficult by their heterogeneous composition, complex morphology and dense vegetation.Here, we explore the interest of integrating UAV surveys in geophysical characterization of NWE-REGENERATIS sites. First, our approach uses photogrammetry to build the digital surface model. Such models can be used to approach deposit volume and improve modelling of the sites. Those are crucial to carry accurate inversion of land-based geophysical data. Secondly, the multi-spectral measurements allow characterizing surface geochemical composition in order to define surface waste characteristics. These data could be used to explain surface electrical resistivity variation. Finally, areas with high metallurgical contents are highlighted with magnetic mapping. There, the ability of UAV to cover areas previously unattainable by land (dense vegetation and/or steep inclines) is key for a better understanding of the site.This methodology is applied to multiple sites, including old iron and zinc factories or uncharacterized industrial landfill. We thus present strengths and weaknesses of each UAV mapping used to characterize metallurgical landfills.
Emerging ecological and environmental hazards in the Himalayas
Authors: Krishnaswamy Jagdish , Daniel Denzil , Sen Sumit , Khanna Jaya
Published: February 2023

The Himalayas are at the forefront of hazards related to climate change as well as other global change drivers such as land-use and land-cover change including complex interactions between diverse drivers.
Scientists, civil society organizations and local communities have identified key issues related to how specific Himalayan ecosystems are responding to these drivers including episodes of greening and browning of vegetation as well spread of Pine and the retreat of Oak forests, higher incidence of forest fire due to changes in winter rainfall and summer heat.
Using evidence from multi-decadal time-series of remotely sensed data on state of vegetation combined with climate data and measurements and observations from instrumented catchments we now have insights on the greening and browning of vegetation at larger scales and the comparative ecohydrological response of Pine and Oak dominated catchments at finer scales.   The Himalayas show elevation specific patterns of greening and browning trends that differ across the Himalayas from west to east.  Pine dominated catchments seem to have lower levels and temporally homogeneous soil moisture profiles as well as higher evapotranspiration and lower discharge regimes compared to Oak dominated catchments.  We discuss the implications of the evidence for biodiversity and ecosystem services under emerging and future climate change.
 
PM10 concentration data analysis monitoring in Volos during the period 2001-2018, Greece
Authors: Proias Georgios , Moustris Kostantinos , Nastos Panagiotis
Published: February 2023

This study investigates the temporal variation of suspended particles with aerodynamic diameter less than or equal to 10 μm (PM10) during an eighteen years period. Mean daily PM10 concentrations between 2001 and 2018, from the monitoring station established in Volos is used. The aim is to investigate the seasonality, intraweek, intraday, weekend effect and spatial variations of the PM10 concentrations as well as trends of data, are statistically studied. The work may assist the formation of PM10 forecasting models of hourly, daily, weekly, monthly and annual horizon. Significant changes observed in PM10 series concentrations dusing the years were found. This may be due to economic and social reasons but also due to measures taken by the state so as to be harmonised with the European Directives concerning the protection of public health and the atmospheric environment of the European Union (EU) members.

Keywords: 
PM10 data series; statistical analysis; Volos; Greece
Earth system impacts of a realistic ocean alkalinization deployment scenario
Authors: Bergman Tommi , Bourgeois Timothée , Schwinger Jörg , Foteinis Spyros , Renforth Phil , Partanen Antti-Ilari
Published: February 2023

Negative emission technologies (NETs) are an integral part of most climate change mitigation scenarios limiting global warming to 1.5 °C above preindustrial levels. Several different NETs have been proposed, including ocean alkalinization that has been considered as one method with high carbon removal potential. To date, most studies on NETs with Earth System Models have been based on idealized scenarios where atmospheric carbon is either simply removed by prescribed amount or some NET is deployed at magnitudes that would be extremely challenging to reach if any economic, technical, or political constraints were considered. 

Here, we present a more realistic global deployment scenario for ocean alkalinization with Ca(OH)2 dispersed at ocean surface in the exclusive economic zones of US, EU, and China, based on their respective production capacities. The dispersion scenario is based on current excess capacities in the lime and cement industries, and high-end projections on how they could evolve until 2100. We use the high-overshoot SSP5-3.4-OS as the socioeconomic background scenario. We simulate the deployment scenario with two different Earth System Models: EC-Earth and NorESM2-LM. In addition to this sophisticated scenario, we carry out an idealized scenario with a uniform addition of 0.5 Gt Ca(OH)2 per year in the same coastal areas. 

The preliminary results show that the idealized 0.5 Gt Ca(OH)2 flux decreased the atmospheric CO2 concentration by 7 ppm in the first 15 years. The effects on ocean carbon uptake and surface ocean pH were strongly localized near the dispersion regions. The early version of the dispersion zone also included the Baltic Sea and the Mediterranean Sea, which led to significant increase in the alkalinity in these sea regions as the water exchange with the wider oceans are limited there. 

By providing a more realistic scenario for ocean alkalinization, we can give also more realistic assessment of climate effects and explore new research questions such as detectability of local changes in pH or carbon fluxes with slowly increasing deployment rates.  
Change of the THM properties of a Malm geothermal reservoir under present and future exploitation schemes
Authors: Gaucher Emmanuel , Egert Robert
Published: February 2023

Sustainable and efficient use of the geothermal resource sitting below the city of Munich (Germany) is a topical issue for the local energy providers. Indeed, by 2035, Munich city expects to supply 100 % of its electricity and heat demand from renewable energies. Hence, the exploitation of the highly conductive aquifers will be intensified with the development of numerous new geothermal power plants. This is a challenging task, which requires better understanding of the coupled processes taking place underground and of their effects, especially in terms of possible induced seismicity and ground uplift or subsidence. These last two concerns are at the heart of the INSIDE research project. The present study focuses on the thermo-hydro-mechanical (THM) modelling of the deep geothermal site in Pullach im Isartal (close to Munich), which constitutes one step to reach the overall project goal.At the Pullach site, since 2005, a deep geothermal reservoir in the Mesozoic Malm is successfully operated and supplies heat to the local grid. A finite-element (FE) reservoir model is developed consisting of eight different lithologies ranging from the crystalline basement to the Earth’s surface. Focusing on the Malm geothermal reservoir, the lithology of interest is subdivided into the three potential and permeable reservoir rocks of the lower, middle and upper Malm. The three geothermal wells are included with their real trajectories and open-hole sections as lower-dimensional elements. The FE model is used to simulate the fully-coupled THM processes taking place under continuous operation using the TIGER open-source application, which is based on the Multiphysics Object-Oriented Simulation Environment (MOOSE).The 3D numerical model was calibrated using hydraulic tests conducted at the wells and the continuous operation of the plant, running for many years, gave the opportunity to assess the simulation results. Consequently, predictions of the long-term changes of the THM characteristics of the geothermal reservoir for the next 50 years are expected realistic. The results show that, under our assumptions and the current operational conditions, exploitation will remain sustainable in the future. Furthermore, near the injection well, a long-term increase in porosity and permeability should be expected due to thermo-poroelastic effects. At last, millimetre-scale uplift could be observed at surface above the injection well.In addition to the present exploitation schemes, several scenarios to increase the exploitation using additional wells are investigated. A similar approach is taken, but particular attention is paid to possible interferences between existing and future neighbouring wells due to enhanced reservoir utilization.
Tropospheric BrO in Arctic Spring 2019 measured by S5-P/TROPOMI - A statistical analysis of the spatial expansion and shape of tropospheric BrO plumes
Authors: Schöne Moritz , Sihler Holger , Warnach Simon , Borger Christian , Herrmann Maximilian , Gutheil Eva , Beirle Steffen , Platt Ulrich , Wagner Thomas
Published: February 2023

Halogen radicals can drastically alter the atmospheric chemistry. In the polar regions, this is made evident by the ozone depletion in the stratosphere (ozone hole) but also by destruction of boundary layer ozone during polar springs. These recurrent episodes of catalytic ozone depletion, better known as “ozone depletion events” (ODEs) are driven by enhanced concentrations of reactive bromine compounds. The proposed mechanism by which these compounds are released into the troposphere is known as “bromine explosion” - reactive bromine is formed autocatalytically from the condensed phase.In comparison to previous satellite missions, the TROPOspheric Monitoring Instrument (TROPOMI) onboard ESA’s S5-P satellite allows an improved localization and a more precise specification of these events due to its superior spatial resolution of up to 3.5 x 5.5 km2. Together with the better than daily coverage over the polar regions, this allows for investigations of the spatio-temporal variability of enhanced BrO levels and their relation to different possible bromine sources and release mechanisms.We present tropospheric BrO column densities retrieved from TROPOMI measurements using Differential Optical Absorption Spectroscopy (DOAS). One advantage of our retrieval is its independence from any external input data, thereby avoiding systematic biases from external datasets. We used a modified k-means clustering and methods from statistical data analysis to separate tropospheric and stratospheric partial columns, relying only on NO2 and O3 columns measured by the same instrument. This ensures in particular that the derived tropospheric BrO data set keeps the same high spatial resolution as the TROPOMI instrument, because no model data with coarse resolution is used. In a second step, the retrieved tropospheric slant column densities (SCDs) are converted to vertical column densities (VCDs).TROPOMI’s improved spatial resolution is then utilized to study the spatial extent and shape of BrO plumes detected in the Arctic region. For this, a combination of morphological filters and connected component labeling is used to provide a statistical overview of all enhanced BrO plumes detected above certain sensitivity thresholds in the Arctic spring of 2019. This provides a lower limit for the spatial extent of enhanced BrO events (and hence also for ODEs) of around 40-60 km. Additionally, seasonal trends in size and shape of the BrO plumes as well as correlations to relevant meteorological parameters are investigated.
Tracing N2O production pathways in aqueous ecosystems by quasi-simultaneous online analysis of 15N in reactive nitrogen species and gaseous emissions
Authors: Mohn Joachim , Huang Kun , Eschenbach Wolfram , Wei Jing , Hausherr Damian , Frey Claudia , Kupferschmid André , Dyckmans Jens , Joss Adriano , Lehmann Moritz F.
Published: February 2023

Natural and engineered nitrogen (N) removal processes in aqueous systems represent important sources of nitrogenous gas emissions, including the potent greenhouse gas nitrous dioxide (N2O). The relevance of microbial and abiotic formation pathways can be assessed using 15N tracing techniques. While 15N-N2O analysis using optical analyzers is straightforward, quantification of 15N fractions in inorganic N compounds, ammonium (NH4+), nitrite (NO2-), and nitrate (NO3-), is typically time-consuming and labor-intensive.In this study, we developed an automated sample-preparation unit coupled to a membrane-inlet quadrupole mass spectrometer (3n-ASSP-MIMS) for the online quasi-simultaneous analysis of 15N fractions in NH4+, NO2-, and NO3-. The technique was designed and validated for applications at moderate (100 - 200 μmol L-1) to high (2 – 3 mmol L-1) N, as found in sewer systems, wastewater in treatment plants, or eutrophic surface waters, and 15N spiking (f15) between 1 and 33%.The potential of 3n-ASSP-MIMS was demonstrated in a feasibility study, where the technique, in conjunction with 15N-N2O analyses by FTIR spectroscopy, was applied to pinpoint nitrifier denitrification as the primary N2O formation pathway during partial NH4+ oxidation to NO2- in a lab-scale sequencing batch reactor.
Densification of air quality monitoring in Nigeria: Progress and challenges
Authors: Ogunjo Samuel , Rabiu Babatunde , Fuwape Ibiyinka , Jenkins Gregory , Obafaye Aderonke
Published: February 2023

Pollution is a major problem in developing countries.  There has been much studies on water pollution and its relation to communicable diseases with little attention to air pollution.  Air quality problem in sub-Saharan Africa is pervasive due to lack of awareness and paucity of reliable data.  The lack of reliable data has limited our underestanding and quantification of its impact on the population.  To address this problem, the the Centre for Atmospheric Research, Nigeria, and the Alliance for Education, Science, Engineering and Design in Africa of the Penn State University collaborated to densify air quality monitoring networks in Nigeria.  The programme has succeeded in deploying over 70 monitoring networks across the country within the last two years. Using data from the network, the impact of air quality especially in relation to diseases have been assessed within Nigeria.   This approach has revealed significant association between air quality and COVID-19 infections.  Furthermore, the available data has helped in understanding the sources of air pollution in different regions of the country.  This is helping in formulating environmental policy, planning, and monitoring for reduction of air pollution.  In this presentation, the progress and challenges in the densification of air quality monitoring stations across the country will be presented.
Atmospheric Chemistry linked to HOx radicals of a Suburban Forest during the ACROSS summer Field Campaign
Authors: Shamas Nesrine , Batut Sebastien , Lahccen Amaury , Michoud Vincent , Cantrell Christopher , Dusanter Sébastien , Brito Joel , Tomas Alexandre , Lahib Ahmad , Jamar Marina , Fittschen Christa , Schoemaecker Coralie
Published: February 2023

Atmospheric Chemistry linked to HOx radicals of a Suburban Forest during the ACROSS summer Field CampaignNesrine. Shamas1, Sebastien. Batut1, Amaury. Lahccen1, Vincent Michoud2, Christopher Cantrell3, Sébastien Dusanter4, Joel Brito4, Alexandre Tomas4, Ahmad Lahib4, Marina Jamar4, Christa. Fittschen1, Coralie. Schoemaecker11 PC2A, CNRS – University Lille, Bât. C11, Cité Scientifique, Villeneuve d’Ascq, France2 LISA, CNRS – Université Paris Cité and Université Paris-Est Créteil, F-94010 Créteil, France3 LISA, CNRS – Université Paris-Est Créteil and Université Paris Cité, F-94010 Créteil, France41IMT Nord Europe, Institut Mines-Télécom, Univ. Lille, Center for Energy and Environment, F-59000 Lille, FranceParis, one of the largest European megacities, transports pollution to different surrounding areas depending on the variation of the wind direction associated with specific meteorological conditions. The relatively unique situation of this isolated megacity from other urban areas make it a suitable location to study the impact of urban emissions on the chemistry of close biogenic environments such as forests and vice versa. In order to investigate this influence, the ACROSS (Atmospheric ChemistRy Of the Suburban foreSt) field campaign was performed during summer 2022, with a measurement site located in the Rambouillet forest. The combination of the data provided during this field campaign from different research groups (such as measurements of VOCs, inorganic species, particle concentration and composition, …) will allow a better understanding of the influence of mixing anthropogenic urban or oceanic air masses, leading to different NO concentrations, with biogenic forestry emissions on the oxidation of tropospheric VOCs. This will ultimately help improving this chemistry within atmospheric models. The UL-FAGE instrument was deployed during the ACROSS campaign, where different types of measurements were performed: OH, HO2, ROx radical quantification at the ground level and OH reactivity. The OH reactivity was alternatively measured at two different levels: below (ground level) and above the forest canopy (top of a 40 m tower). Clear stratification was observed during the night with a higher OH reactivity at the ground level than above the canopy. Comparison between the measured and the calculated OH reactivity allows to identify the diurnal missing reactivity at both levels. Preliminary results of the OH reactivity and the radical quantification will be presented.References[1] Baklanov et al., Advances in Science and Research, 4, 115–120, 2010[2] MEGAPOLI campaign 2009-2010 special issue, https://acp.copernicus.org/articles/special_issue248.html page, accessed 24 May 2019
Glacial abrupt climate change as a multi-scalephenomenon resulting from monostable excitabledynamics
Authors: Riechers Keno , Gottwald Georg , Boers Niklas
Published: February 2023

During past glacial intervals the high northern latitude’s climate was punctuated by abrupt warming events which were accompanied by a sudden loss of sea ice, a reinvigoration of the Atlantic Meridional Overturning Circulation (AMOC), and cooling of the Nordic Seas. Despite being considered the archetype of past abrupt climatic change, to date there is no consensus about the physical mechanism behind these so-called Dansgaard-Oeschger events and the subsequent milder interstadial phase. Here, we propose an excitable model system to explain the DO cycles, in which interstadials are regarded as noise-induced state space excursions. Our model comprises the mutual multi-scale interactions between four dynamical variables representing Arctic atmospheric temperatures, Nordic Seas’ temperatures and sea ice cover, and AMOC. Crucially, the model’s atmosphere-ocean heat flux is moderated by the sea ice variable, which in turn is subject to large perturbations dynamically generated by fast evolving intermittent noise. If supercritical, these perturbations trigger interstadial-like state space excursions seizing all four model variables. As a physical source for such a driving noise process we propose convective events in the ocean or atmospheric blocking events. The key characteristics of DO cycles are reproduced by our model with remarkable resemblance to the proxy record; in particular, their shape, return time, as well as the dependence of the interstadial and stadial durations on the background temperatures are reproduced accurately. In contrast to the prevailing understanding that the DO variability showcases bistability in the underlying dynamics, we conclude that multi-scale, monostable excitable dynamics provides a promising alternative candidate to explain the millennial-scale climate variability associated with the DO events.