bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemistry-albedo feedbacks from reforestation partially offset CO2 removal benefits
Authors: Weber James , King James A. , Abraham N. Luke , Grosvenor Daniel P. , Beerling David J. , Lawrence Peter , Val Martin Maria
Published: February 2023

Reforestation is widely proposed for carbon dioxide (CO2) removal but the impact on climate, via atmospheric composition and surface albedo changes, remains relatively unexplored. Using two Earth System models, UKESM1 and CESM2, we compare scenarios where existing forests expand to a near biophysical limit (with croplands fixed at 2015 to preserve food production) with SSP1-2.6 and SSP3-7.0 at 2050 and 2095.  In the reforestation scenario, global BVOC emissions are 18% (35%) higher than SSP3-7.0 at 2050 (2095) and 8% (12%) higher than SSP1-2.6. The resulting increases to secondary organic aerosols and aerosol scattering, from BVOC emission changes, drive a negative radiative forcing (RF). However, this is outweighed by the positive RF from increases to methane and ozone and decreases to surface albedo.The net RF is equivalent to CO2 increases of 13 (32) ppm relative to SSP3-7.0 at 2050 (2095) and 3 (8) ppm relative to SSP1-2.6. These indirect factors offset ~25% of the additional CO2 removal arising from reforestation relative to SSP3-7.0 and ~10% relative to SSP1-2.6. This highlights the importance of assessing the full response of the Earth System to reforestation, rather than just the potential CO2 removal.  
Investigating the role of temperatures in proxy-based pCO2 estimates: An integrated model-proxy approach
Authors: Witkowski Caitlyn , Farnsworth Alex , Valdes Paul
Published: February 2023

Atmospheric concentrations of carbon dioxide (pCO2) play a critical role in a number of earth system components, including the biosphere, geosphere, and atmosphere. Understanding how pCO2 has changed over geologic time may provide critical context for predicting future climate scenarios. However, constraining past pCO2 values remain a challenge in paleoclimate studies due to difficulties in constraining proxy calculation parameters. Marine-based pCO2 proxies rely on at least one temperature parameter (i.e., via Henry’s Law to convert dissolved CO2 concentrations from the ocean into atmospheric pCO2), which is difficult to constrain in deep-time. Here, we highlight the importance of temperature and propose a new method of model-derived temperatures based on the paleo-location of the sample site. This methodology can be applied to any pCO2 proxy with temperature input; here we use the example of the pCO2 proxy based on the stable carbon isotopic composition of phytane, the diagenetic product of chlorophyll-a, due to its spatial and temporal ubiquity over the past ca. 465 million years.
Modeling water flow rate and soil erosion in Mediterranean headwaters (with or without check dams) under land use and climate change scenarios using SWAT
Authors: Zema Demetrio Antonio , Carrà Bruno Gianmarco , Lucas Borja Manuel Esteban , Filianoti Pasquale Giuseppe Fabio , Perez Cutillas Pedro , Conesa Garcia Carmelo
Published: February 2023

The use of check dams is a common strategy to contrast soil erosion in the Mediterranean headwaters. However, the effects of these control works on water flow rates and sediment yields have been scarcely investigated under possible scenarios of climate and land use changes. On this regard, the use of hydrological models, such as SWAT, provide reliable hydrological predictions under variable environmental conditions. To fill this gap, this study has evaluated the effectiveness of check dams on the hydrological response of a forest headwater in Calabria (Southern Italy) in comparison to an unregulated sub-catchment with very similar environmental conditions. On this regard, the effects of different combined scenarios of climate change (through three GCMs and two RCP applied to the next 80 years) and land use (forest, pasture, and cropland) on water flow rates and sediment yields in the two headwaters were analysed using the SWAT model. SWAT was first calibrated in a third headwater with very similar climatic, soil and land use conditions, and this verification showed a satisfactory prediction capacity of water flow rate. The water flow rate prediction capacity of the model was satisfactory (coefficients of determination and efficiency of Nash and Sutcliffe equal to 0.71 and 0.67, respectively, and percent bias of 14.9%). No significant differences were detected for the water flow rates and sediment yields between the two sub-catchments (with or without check dams) among the different land uses and climate change scenarios. This was linked to the low hydrological response of both headwaters to the forcing actions, which influenced the low effectiveness of the control works. SWAT estimated higher values of both mean and maximum values of water flow rates and sediment yields under RCP2.6 compared to RCP8.5. Both water flow rates and sediment yields will be very low under all climate and land use scenarios. The regulated headwater with check dams will always produce more runoff and erosion compared to the sub-catchment without check dams. The increases will be up to 60% for the maximum flow rate and 30-35% for the sediment yield in forest land use and under RCP2.6. Although the limitation of this study linked to the lack of validation of the erosion data (due to unavailable records of sediment yield), this study has demonstrated how the use of check dams in headwater catchments may be not effective several decades after their installation for soil conservation purposes in Mediterranean semi-arid areas, where the water flow and erosion rate are limited.
300 years of organic pollution recorded in an urban speleothem (Paris, France)
Authors: Garagnon Julia , Perrette Yves , Naffrechoux Emmanuel , Pons-Branchu Edwige
Published: February 2023

The preservation of water resources and the limitation of pollution are an environmental central issue in the current intense anthropization context. Considered as sensitive recorders of past changes, speleothems offer an under investigated natural archive for the reconstruction of water quality. Urban speleothems have recently been used to show the impact of urbanization over the water quality using inorganic trace elements. Speleothems thus represent a promising archive of water quality on short and long-time scales. However, they have never been used to trace organic pollution. Within the organic and anthropogenic proxies, polycyclic aromatic hydrocarbons (PAHs) are commonly used in water quality analysis. These persistent organic pollutants (POPs) are mainly due to anthropogenic emissions. The use of speleothem to trace the variations in quantity and quality of organic matter, including organic pollutant as PAHs, over the last centuries, is unprecedented.For this purpose, high resolution (10 µm) solid phase UV fluorescence imaging analyses were crossed with chemical analyses (PAHs, Non Purgeable Organic Carbon (NPOC)) carried out on low weight samples (a few mg to g) from a Parisian aqueduct flowstone. Solid-phase fluorescence imaging, although poorly applied yet to speleothems, is a non-destructive technique. To obtain quantitative information, solid phase spectroscopy is coupled with liquid phase compound analysis and NPOC analysis. Due to their low concentration, the analysis of PAHs required a long development phase. The protocol consists of an extraction and analysis process using high performance liquid chromatography coupled with a fluorescence detector. The first results reveal the presence of PAHs for 300 years in runoff water with an increase, in particular in heavy molecular weight PAHs, over the last two decades. These data will be crossed with modelled imaging of quantitative variations in organic matter. This work opens the way to a better long term understanding of the impact of anthropization on transfer of pollutants in subsurface waters.
Predictability of blocking and zonal flow regimes in a reduced-order land atmosphere coupled model
Authors: K Xavier Anupama , Demaeyer Jonathan , Vannitsem Stéphane
Published: February 2023

Low-frequency variability (LFV) encompasses atmospheric and climate processes on time scales from a few weeks to decades.​ This includes atmospheric blockings, heat waves, cold spells, and at longer time scales long-term oscillations like the MJO, the NAO, ENSO….. Better understanding of LFV, could contribute to improved long term forecasts​. Identifying and evaluating LFVs in GCMs is computationally expensive, so in this study an idealised low order coupled model is used. They are climate models ‘stripped to the bone’,  which links theoretical understanding to the complexity of more realistic models, made by key ingredients and approximations​; which hence helps us to study a particular phenomenon by tweaking the parameters affecting them with less computational cost​. The Quasi Geostrophic land atmosphere coupled model is a python implementation of mid-latitude atmospheric model​ with two layer quasi geostrophic channel atmosphere on beta -plane​ coupled to a simple land portion.  The system exhibits blocking conditions at different time scales depending on the incoming solar radiation and also experiences transitions from blocking to zonal flow after applying different sets of parameters to the model. The predictability and persistence of these regimes is investigated by calculating the local lyapunov exponents at the specified transition points and around them.  The findings are discussed in the perspective of the current literature on the predictability of blocking.
Changing Atlantic Freshwater Transports in Response to Future Climate Projections
Authors: Mecking Jennifer , Drijfhout Sybren , Sinha Bablu
Published: February 2023

Changes in Atlantic meridional freshwater transports have been hypothesized to play an important role in Atlantic Meridional Overturning Circulation (AMOC) stability, redistributing precipitation and evaporation and dynamic sea level changes.  Freshwater transports can be altered by both changes in ocean circulation and changes in salinity.  In this study CMIP5 and CMIP6 models are analyzed to investigate how salinity and velocity changes impact the freshwater transports in the ScenarioMIP future projections.  In the multi-model means of CMIP5 and CMIP6 data there is only a slight increase (< 0.1Sv) in southward freshwater transport across the Atlantic basin.  This slight increase comes from a balance of changes in overturning (zonal mean) and azonal freshwater transports.  The changes in overturning and azonal freshwater transports are largest in the subtropical Atlantic where the salinity driven azonal changes drive an increase in southward freshwater transport which are almost completely counteracted by a velocity driven overturning freshwater transport.  Changes in these freshwater transports are larger in CMIP6 relative to CMIP5, which is especially noticeable in the velocity driven overturning changes (due to the larger AMOC weakening in CMIP6) and salinity driven azonal changes (due to a comma shaped freshening pattern in the North Atlantic, typically associated with a weakening of the AMOC).
Study on the Flow Field Variation in Fracture Channel of Coalfield Fire
Authors: Li Qing-Wei , Fan Hui-Pan , Ren Li-Feng , Xiao Yang , Zeng Qiang
Published: February 2023

The coalfield fire area is widespread in the world. Numerous coal resources have been destroyed because of the large-scale coalfield fires. Meanwhile, toxic and harmful substances, such as carbon monoxide, carbon dioxide, methane, sulfide, and nitrogen oxide, etc., are numerously generated. All of them threat the local ecological environment and the economic development. The occurrence and evolution processes are complex, challenging the scientific prevention and control for coalfield fire. Gas transport mechanism is one of the key points that influence coalfield fire evolution and its efficient prevention and control. This investigation mainly pays attention to the flow filed in underground coalfield fire area. Combining physical test and numerical simulation, the transition law of the main air supply channel in underground coalfield fire area is studied, and the distribution characteristics of flow field in the channels are revealed. These are of great significance for revealing the evolution process of coalfield fire.
Geoethics values clarification: A playable poster
Authors: Crookall David , Promduangsri Pimnutcha
Published: February 2023

Values underlie geoethics and geoscience, especially climatology.  Can we understand or build geoethics without reference to values?  Are values and geoethics driven by beliefs, or should values remain unchanged despite changing beliefs?  Those are some of the questions that we may ask when considering ethics in life, in the geosciences and in climate change and action.  Values include honesty, compassion, quality, patience, objectivity, truth, respect, individualism, justice, power, peace and beauty.  How are these related to geoethics?  Often an ethical dilemma stems from two or more underlying value conflicts, such as individual identity and social value.  It is not easy to understand the principles and dynamics of such relations.One way into this quagmire is by using a values clarification exercise or game (VCE or VCG).  A VCE can be a useful geoethics literacy tool to help people explore the complexities of such relationships, to allow them to express their own ideas, to confront their ideas with those of others and to gain a rich understanding of their own values that underlie geoethics.  Undorf and colleagues (eg, https://doi.org/10.5194/egusphere-egu22-12732, https://doi.org/10.1007/s10584-022-03435-7) have adopted a philosophical approach.  We take an easier approach, that of interactive, participatory gaming.We have designed and used VCEs and VCGs in a variety of cultural and social settings and with encouraging results.  Our poster will outline our prior experience and allow you to participate, albeit superficially, in a VCE.  Please come to see us during the poster session, and be sure to bring along one or two friends so that you can play; three players is better than two.  Also bring some paper and a pen.
A comparison of inverse methods and basal sliding laws applied to a hindcast model of Jakobshavn Isbræ from 2009 to 2018.
Authors: Trevers Matt , Payne Tony , Cornford Stephen
Published: February 2023

Jakobshavn Isbræ (JI), on the West coast of Greenland, is one of the fastest flowing outlet glaciers of the Greenland Ice Sheet, draining 7% of the ice sheet area. Since the late 1990s it has dramatically accelerated, thinned and retreated in a series of phases alternating with periods of quiescence. It exhibits strong seasonal variations in flow speed and calving front position. Between 2012 and 2015, JI attained its point of furthest retreat and flow speeds in excess of 17 km/yr. Since 2016 it has modestly thickened, concurrent with deceleration and readvance of the calving front.The very fast flow and strong annual and interannual variability present significant challenges for ice sheet modellers. We model the evolution of JI between 2009 and 2018 using the BISICLES ice sheet model. The standard modelling technique of assimilating surface velocity observations to infer a power law basal friction coefficient for a snapshot in time fails to account for rapidly changing basal conditions, underestimating the annual variability. We implement a time-series inverse method in which regular velocity observations are assimilated throughout the study period to produce a time-evolving basal friction coefficient. This method is able to reproduce the large annual variations in flow speed much more accurately than the static method.This reliance on regular observations to drive the model poses a problem for future projections. We compare a range of sliding laws applied with the normal snapshot inverse method. A modern regularized Coulomb friction sliding law is better able to reproduce JI’s annual variations in flow speed due to its ability to modulate the basal friction in response to movement of the grounding line. As a result, it may be a more appropriate choice of sliding law for modelling the future evolution of fast-flowing outlet glaciers.
Evaluation of satellite-derived NOx emissions over Europe
Authors: van der A Ronald , Ding Jieying , Mijling Bas , Eskes Henk , Guevara Marc
Published: February 2023

Nitrogen oxides (NOx) emissions play an important role in air quality, the nitrogen cycle, and as precursor for climate gasses. The most important sources of NOx emissions are fossil fuel burning (industry and traffic) and the release from soil.With the inversion algorithm DECSO (Daily Emissions Constrained by Satellite Observations) we derive quantitative NOx emissions on a 5 to 20 km resolution from TROPOMI (on Sentinel 5p) observations of NO2, taking advantage of the fine spatial resolution (5 x 3.5 km) of the TROPOMI instrument. DECSO is a full inversion algorithm based on data assimilation of satellite observation and the Chemical-transport model CHIMERE. For the data assimilation a Kalman Filter technique is used. For the inversion no apriori information of the NOx emissions is needed and for this reason new sources can be detected. In the postprocessing we use the seasonal cycle to distinct between soil emissions (having strong seasonal cycle with summer peak) and anthropogenic emissions (having low variability over the year).To assess the quality of satellite-derived NOx emissions on various scales, i.e. national, regional, city and points-sources, they are compared to various bottom-up inventories. For bottom-up emissions we selected NEC (National Emission Ceilings Directive inventory), LRTAP (LRTAP convention data), the CAMS (Copernicus Atmosphere Monitoring Service) regional anthropogenic emission database and the high-resolution emission inventory HERMES (High-Elective Resolution Modelling Emission System) for Catalonia. Detailed results will be shown, including the spatial and temporal variation per emission category.
Sources, propagation and sinks of Europe’s major heat waves; a complex network analysis of heat extremes
Authors: Garcia-Marti Irene , van der Schrier Gerard , Polak Florian
Published: February 2023

In the last few decades, Europe has seen many devastating heat waves; each one producing new all-time heat records and pushing the limits of climatic extremes. The quantification of the dynamical linkage, the evolution and propagation of such heatwaves is a start to understand these processes. This network structure and propagation characteristics for European heatwaves is analyzed using a complex network approach based on E-OBS, the gridded dataset based on in situ data from the European meteorological services.
Complex networks (CN) are data-driven methods suited to model natural non-linear dynamic systems (Dijkstra et al., 2019). CN are based on graph theory; hence a network is composed by two sets (nodes and vertices) conforming a network topology that can be subsequently explored. In this work, we process European-wide daily maximum temperature gridded layers to build up a CN capable of shedding light on interesting mechanisms underlying the heatwave propagation. We identify the source and sink regions primarily responsible for heatwave propagations and the strength of association between these regions. The network coefficients are derived to evaluate the extremal dependence, evolution, and spatial propagation of specific large scale heatwave events.
Enabling the tracking of climate extremes such as heatwaves might be a relevant resource to help evaluating climate attribution methodologies and expanding them further having this visual support. In addition, having a more realistic representation of a heatwave might help reduce uncertainties, hence better guiding the decision-making process. Both types of contributions might be of service at issuing weather warnings tailored to regions, therefore improving the social preparedness and response capacity when heatwaves hit a region (e.g. excess human mortality associated with heat stress).
ReferencesDijkstra, H. A., Hernandez-Garcia, E., Masoller, C., & Barreiro, M. (2019). Networks in Climate. Cambridge: Cambridge University Press, Cambridge, UK and New York, NY, USA. 
An extended stochastic and probabilistic hazard event set for Europe for use in multi-hazard studies
Authors: Schaefer Andreas , Daniell James , Claassen Judith , de Ruiter Marleen , Brand Johannes
Published: February 2023

There are a number of European level datasets which have been produced over the last decade for natural perils to provide stochastic and probabilistic results at sites, or across the whole of Europe. As part of the MYRIAD-EU project, a key review of historical individual and multiple peril datasets has been made in order to create a compendium of useable results for regional level analysis in MYRIAD.It uses datasets from SERA-EU, SHARE and ECA for earthquake, RAIN and PRIMAVERA for weather-related disasters such as storms, tornadoes and other events, historical volcanic eruption data from LAMEVE and VOGRIPA, hydrological data and past flood events from databases such as the work of DFO, MODIS, datasets from VU Amsterdam and other research institutions, and bushfire data from EFFIS and other local databases as well as heat wave and cold wave data from multiple datasets.Where possible, stochastic event sets have been created in order to allow for concurrent and coinciding events to be identified. In many cases, stochastic event sets have not yet been able to be implemented and should be considered as a first step towards a fully event based process. As part of the scenario studies within MYRIAD-EU, probabilistic results will be turned into specific events in order to examine the risk and feedback loops associated with the different event combinations.This effort has been placed on the MYRIAD-EU Zenodo, and provides the basis for studies into risk in terms of concurrent disasters.
Data Mining at school with InSight space mission
Authors: Berenguer Jean Luc , Tartaru Dragos , Balestra Julien , Saliby Christelle
Published: February 2023

InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) is a discovery program, lead by NASA, that has landed a single lander on Mars and other sensors, such as a seismometer, a heat flow probe, and more others sensors that provided a lot of data.
The main payload is the seismometer called SEIS, that is the first seismometer (after Viking fail) to record signal with a very deep precision. The goal of this mission is to investigate the dynamics of Martian tectonic activity and understand all the processes that shaped the Red Planet.
Pupils were able to benefit from the data recorded by SEIS, and transmitted, with little delay, to schools by the science team. In this presentation, we will show all the practical activities done with kids, teens and students in France and other countries during the space mission (2018-2022).
This work has been done by a French team of teachers, in international cooperation with others countries (with UK, USA, Switzerland, Spain, Romania ...) and can be found on this specific website: https://insight.oca.eu
As the InSight mission draws to a close, a survey was conducted within the Education community to assess the impact of such an education component in a research programme.
Beyond Mesoscale off Mauretania
Authors: Dietze Heiner , Löptien Ulrike , Hordoir Robinson , Renz Matthias
Published: February 2023

Hitherto unresolved oceanic sub-mesoscale variability may retard air-sea exchange of heat and carbon in contemporary IPCC-type model projections. Here, we set out to put this hypothesis to the test in the Atlantic in a region off Mauretania that is renown for its complex coastal dynamics. Results from a suite of coupled ocean-circulation biogeochemical models suggest that the oceanic bottleneck between the atmosphere and the vast abyssal stocks of heat and carbon is relatively insensitive in the range from mesoscale and to sub-mesoscale resolution. More specifically we find that the sensitivity of effective vertical mixing to changes in spatial resolution is comparable to infamous uncertainties associated with contemporary numerical algorithms.
Going with the flow: Initial soil structure development by percolating dissolved organic matter
Authors: Kögel-Knabner Ingrid , Bucka Franziska B. , Felde Vincent J.M.N.L. , Peth Stephan
Published: February 2023

Percolating dissolved organic matter (DOM) from the topsoil is considered the main source of subsoil organic carbon (OC) in temperate soils. Although DOM adsorption to minerals has been extensively studied, comprehensive knowledge about its influence on subsoil OC storage and structure development is limited.We conducted a short-term incubation experiment using artificial model soils without pre-existing aggregates to study the effects of percolating DOM within varying soil textural conditions on OC turnover and initial structure development.The model soils were designed with contrasting texture (clay loam, loam, sandy loam), but identical mineral composition (quartz, illite, montmorillonite, goethite), mimicking subsoil conditions, where mineral surfaces free of OM come into contact with percolating DOM. The regular application of DOM under a constant suction head (-15 kPa) enabled the DOM to percolate freely through the soil matrix over the course of the experiment.A higher sand content caused a lower porosity, which was accompanied by a lower moisture content. In contrast, the OC retention (21% of the OC input), and the microbial abundance and activity were unaffected by the soil texture. The percolating DOM created patches of OM covers on 10% of the mineral surfaces (N2-BET) within an otherwise OC-free mineral matrix.The biochemical processing of the percolating DOM solution induced the formation of large, water-stable aggregates (wet-sieving) in all textures without requiring the presence of physical organic nuclei. Aggregate formation was pronounced in the clay-rich soils (58% mass contribution), which also exhibited a higher mechanical stability of the aggregates.The results highlight that retention and microbial mineralization of dissolved OM are decoupled from pore sizes and soil solution exchange, but are instead driven by the mineral composition and OC input.The biochemical processing of percolating DOM can induce large soil aggregates. Here, the presence of fine mineral particles enhances the formation and mechanical stability of the aggregates, irrespective of their surface charge or sorption properties.
Remote Sensing for large-scale agricultural investment areas in Ethiopia – agricultural monitoring based on Earth observation time-series
Authors: Eisfelder Christina , Sogno Patrick , Alemu Genanaw , Hailu Rahel , Mesmer Christian , Huth Juliane
Published: February 2023

Ethiopia is known to be currently food insecure and suffering from considerable food deficits. The Government of Ethiopia strives to increase the agricultural production and its efficiency. Therefore, Ethiopia has been promoting large-scale agricultural investment (LSAI) to transform the agricultural sector. However, the progress by agricultural development has been limited. Investors only developed a small fraction of the transferred land. Therefore, there is a great need for monitoring of the implementation and actual state of land use of every LSAI project. The use of remote sensing can substantially support agricultural monitoring. In this study, Earth observation time series are analyzed to examine the land used for agricultural production and to differentiate crop types grown within the three study areas. Current land use/land cover (LULC) is analyzed using Sentinel-2 time series to identify cropland areas. In a second step, remote-sensing time-series of Sentinel-1 and Sentinel-2 are used to differentiate among 20 different crop types grown in the region. The developed classification methods have been applied to derive information products for three study regions in Ethiopia including the LSAI areas within the provinces of Amhara, Benishangul, and Gambella. The methods and derived information products on LULC and crop types will be made available to GIZ and regional experts to support agricultural monitoring of developed land in Ethiopia.
Crustal Features of Eastern Anatolia based on a Joint Grid Search Performed over Receiver Functions and P-wave Coda Autocorrelation
Authors: Aygün Hazal , Eken Tuna , Keleş Derya , Kaya-Eken Tülay , Cammarano Fabio , Delph Jonathan R. , Taymaz Tuncay
Published: February 2023

The complex tectonic structure of eastern Anatolia results from the superposition of subduction and collisional structures along a long-lived convergent margin between the Gondwanan (Arabian) and Eurasian plates. The geodynamic processes shaping the tectonic setting and uplifting history of the region still remain enigmatic despite the fact that the number of geophysical, geological, and petrographic-based models/interpretations in recent years has increased notably. Further issues, i.e., how the spatiotemporal patterns of seismic activity are controlled by pre-existing deformational zones in the lithosphere and/or modern convergent stresses, and how magmatism is related to the lithospheric variability along the margin, are unclear. Models of seismological features of the Earth’s interiors provide insights on isotropic heterogeneity that are of great importance for constraining the current physical and chemical conditions, as they likely control the localization of structures. For this purpose, the present study aims to constrain lateral variations of crustal thickness, Moho topography, and average seismic velocities (Vp, Vp/Vs) by leveraging information from both teleseismic scattered (receiver function) and reflected (autocorrelation) waves (H-k-Vp stacking). Incorporating teleseismic autocorrelation waveforms from the P-wave coda, we can better constrain average crustal P-wave velocities (Vp) by highlighting the amplitude term of the Moho-reflected Pmp phase. Our dataset consists of digital waveforms extracted from 512 teleseismic events (within the epicentral distance range from 30° to100° and with Mw>6) observed at 33 permanent broadband seismic stations operated under the KOERI network between 2013 and 2022 and will result in a new map of crustal architecture and its physical properties (crustal thickness, Vp, and Vp/Vs) below eastern Anatolia. Preliminary results indicate a thickening crust from south to north reaching down to depths of ~50 km. High Vp/Vs ratios mark volcanic provinces as well as fault damage areas presumably characterized by highly fractured rocks with high amounts of water content. Lateral variations of P-wave velocities along two continental fault zones (EAFZ and NAFZ) of the region imply that the degree of shear deformation and resultant seismic activity is well-correlated with density/seismic wave speed variations. Moho depth variations across the NAFZ further suggest a much narrow and localized distribution of deformation in the lower crust and upper mantle compared to the EAFZ. Further analysis of these results will lead to a better understanding of the controlling mechanisms behind seismicity and magmatism in the Eastern Anatolian Plateau.
(How) can we attribute West Antarctic ice mass loss to climate change?
Authors: Bradley Alexander , Bett David , Williams C. Rosie , Arthern Robert , Holland Paul , De Rydt Jan
Published: February 2023

The West Antarctic Ice Sheet is thinning and losing mass at an accelerating rate. However these changes have yet to be formally attributed to anthropogenic climate change, primarily because of the potential for positive feedbacks on ice sheet mass loss which may have been triggered even within the limits of natural internal climate variability. This begs the question: has the thinning, mass loss, and ultimately sea level rise from Antarctica resulted from anthropogenic changes? Or, is the ongoing mass loss simply the result of a positive feedback playing out on the long timescales on which ice sheets evolve? We have developed a framework to address this question, in which forcing is applied via variable ice-shelf basal melt rates with large internal variability. This framework is suitable, in particular, for use in systems with strong feedback potential. An idealised example shows that this framework permits statistically robust attribution statements to be made, even in systems that are highly susceptible to feedbacks, demonstrating the feasibility of such attribution studies for the West Antarctic Ice Sheet.
Reconstructing spatial variability of forest soil water characteristic by using a combination of electrical resistivity tomography and local soil water content measurements
Authors: Noell Ursula , Hemmens Erkki , Ahrends Bernd , Stadler Susanne , Fleck Stefan , working group Klibw-gw
Published: February 2023

Effective management of groundwater resources requires conclusive evidence and understanding of forest management effects (tree species selection, harvest intensities, forest rotation periods) on groundwater recharge. The high spatial variability of forest soil characteristic hampers an area representative measurement of forest soil moisture distribution and flow processes in the unsaturated zone. This results in high uncertainties in the detection of tree species difference of water balance and groundwater recharge in forests. We attempt to delineate this heterogeneity by combining different investigation methods and forest stands of different tree species. From 2019 – 2022 we investigated a Norway spruce stand (Picea abies (L.) KARST.) in the Solling mountains (AMT 7.3°C, AMP 1168 mm). The observation shows higher moisture contents close to the trees, where the root density is highest. We calculated a site-specific function relating electrical resistivity to soil water content and used this to reconstruct moisture changes down to a depth of one meter below the rooting zone. Recharge seems to happen not only in winter but also in summer after intense precipitation events. During a severe spring drought in 2020, the water content dropped markedly in the rooting zone. In 2022 we started the observation of the water balance in a lowland Scots pine stand (Pinus sylvestris) with locally regenerating red oak (Quercus rubra) in the shrub layer. The geophysical monitoring using electrical resistivity tomography discovered again lower resistivity indicating higher moisture content close to the trees where root density is highest. The application of different inversion smoothness constraints revealed differences in resulting electrical resistivity values, showing the non-uniqueness of the inversion results. This presents a challenge, relating single point soil water measurements to ERT 3D inversion results and calls for the need to construct a site-specific Archie function by using simultaneous water content measurements at the site rather than laboratory measurements. The investigations will continue in stands of Douglas fir (Pseudotsuga mentiesii), red oak (Quercus rubra), common oak (Quercus robur) and European beech (Fagus sylvatica).The project is funded by the Forest Climate Fond under the joint leadership of BMUV and BMEL (Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection and the Federal Ministry of Food and Agriculture (KLIBW-GW:FKZ: 2220WK39B4 and 2220WK39B4)).
Tracing Atlantic water exiting the Fram Strait and its transit in the Arctic Ocean by isolating reprocessing-derived 236U and colored dissolved organic matter
Authors: Lin Gang , Qiao jixin , Gonçalves‐Araujo Rafael , Steier Peter , Dodd Paul , Stedmon Colin
Published: February 2023

The Fram Strait, located between Svalbard and Greenland is an important gateway for exchange of salt and heat between the Arctic Ocean and the North Atlantic Ocean and is also a geographically crucial region for investigating Atlantic water transport pathways and transit times, which are necessary to understand the progress of environmental changes in the Arctic. 236U from the two European nuclear reprocessing plants (RPs) at La Hague (LH) and Sellafield (SF) provides a unique signal in Atlantic water for studying its circulation pattern in the Arctic Ocean. In this study we first isolate RP-derived 236U (236URP) using the characteristic 233U/236U signature and then use colored dissolved organic matter (CDOM) to indicate transit pathways and therefore constrain the selection of appropriate 236URP input functions. High CDOM absorbance in the Fram Strait reflects the passage of Atlantic water transported to the Arctic by the Norwegian Coastal Current (NCC) and subsequently along the Siberian shelf where the Ob, Yenisei and Lena rivers supply terrestrial organic matter with high CDOM levels. Conversely low CDOM water represents Atlantic water that has remained off the shelf. Based on CDOM absorbance, potential temperature (θ) and water depth the path of a given body of Atlantic water could be determined and an appropriate RP input function selected so that transit times could be estimated. Waters with high CDOM levels sourced from the NCC and Barents Sea branch water (BSBW) had an average Atlantic water transit time of 12 years. Waters with low CDOM,  θ < 2 °C, and depth < 1500 m were sourced from the Norwegian Atlantic Current (NwAC), had little interaction with riverine freshwater with an advective Atlantic water transit time of 26 years.
Facilitating provenance documentation with a model-driven-engineering approach.
Authors: Bastin Lucy , Reynolds Owen , Garcia-Dominguez Antonio , Sprinks James
Published: February 2023

Evaluating the quality of data is a major concern within the scientific community: before using any dataset for study, a careful judgement of its suitability must be conducted. This requires that the steps followed to acquire, select, and process the data have been thoroughly documented in a methodical manner, in a way that can be clearly communicated to the rest of the community. This is particularly important in the field of citizen science, where a project that can clearly demonstrate its protocols, transformation steps, and quality assurance procedures have much more chance of achieving social and scientific impact through the use and re-use of its data.A number of specifications have been created to provide a common set of concepts and terminology, such as ISO 19115-3 or W3C PROV. These define a set of interchange formats, but in themselves, they do not provide tooling to create high-quality dataset descriptions. The existing tools built on these standards (e.g. GeoNetwork, USGS metadata wizard, CKAN) are overly complex for some users (for example, many citizen science project managers) who, despite being experts in their own fields, may be unfamiliar with the structure and context of metadata standards or with semantic modelling. In this presentation, we will describe a prototype authoring tool that was created using a Model-driven engineering (MDE) software development methodology. The tool was authored using JetBrains Meta Programming System (MPS) to implement a modelling language based on the ISO19115-3 model. A user is provided with a “text-like” editing environment, which assists with the formal structures needed to produce a machine-parable document.This allows a user to easily describe data lineage and generic processing steps while reusing recognised external vocabularies with automated validation, autocompletion, and transformation to external formats (e.g. the XML format 19115-3 or JSON-LD). We will report on the results of user testing aimed at making the tool accessible to citizen scientists (through dedicated projections with simplified structures and dialogue-driven model creation) and evaluating with those users any new possibilities that comprehensive and machine-parsable provenance information may create for data integration and sharing. The prototype will also serve as a test pilot of the integration between ISO 19115-3 and existing/upcoming third-party vocabularies (such as the upcoming ISO data quality measures registry).
Plasmaspheric wind in the Earth’s magnetosphere: contribution to the early evolution of the terrestrial atmosphere
Authors: Dandouras Iannis
Published: February 2023

The Earth’s plasmasphere dominates the mass content of the inner magnetosphere. During extended periods of relatively quiet geomagnetic conditions the outer plasmasphere can become diffuse, with a gradual fall-off of plasma density. During increasing magnetospheric activity, however, the plasmasphere is eroded and plumes, forming at the plasmapause and released outwards, constitute a well-established mode for plasmaspheric material release to the Earth’s magnetosphere. These plumes are associated to active periods and the related electric field change. In 1992, Lemaire and Shunk proposed the existence of an additional mode for plasmaspheric material release to the Earth’s magnetosphere: a plasmaspheric wind, steadily transporting cold plasmaspheric plasma outwards across the geomagnetic field lines, even during prolonged periods of quiet geomagnetic conditions. This has been proposed on a theoretical basis. The Cluster spacecraft, that cross the plasmasphere from south to north during their perigee passes, provided for the first time an experimental confirmation of the plasmaspheric wind. This is based on the analysis of ion measurements acquired by the CIS experiment onboard these spacecraft, which allows also to study the plasmaspheric dynamics under various geomagnetic activity conditions. The plasmaspheric wind has been systematically detected in the outer plasmasphere during quiet and moderately active periods, and provides a contribution to the magnetospheric plasma populations outside the Earth’s plasmasphere.During the early terrestrial evolution (around 2 to 4 billion years ago), when the Earth’s rotation period around its axis was much shorter, the imbalance between gravitational, centrifugal and pressure gradient forces, giving rise to the plasmaspheric wind, should generate much stronger outflows. The plasmapheric wind should then have played an important role in the early evolution of the terrestrial atmosphere, through enhanced atmospheric escape, including the escape of heavy elements (C+, N+, O+).   
Why rainwater is harvested in different ways and what this means for household water insecurity – findings from a mixed-methods study in rural South Africa
Authors: Lebek Karen , Krueger Tobias
Published: February 2023

Worldwide, rainwater harvesting (RWH) is gaining importance as alternative water source for water insecure households that face drought and water scarcity. RWH is especially useful in the widely dispersed settlements of rural South Africa, where water infrastructure and services are only partially developed and often dysfunctional and unreliable. Surprisingly, according to previous studies and data from the South African General Household Survey, only 1 to 3 % of South African households practice rainwater harvesting; however, these studies and surveys have only considered conventional RWH systems, i.e. industrially manufactured gutters and large 4 to 6kl-tanks. In our case study in rural Kwazulu-Natal, over 90% of households practiced RWH, yet only 25% harvested rainwater in a conventional way. The majority of households collected rainwater in what we call a “makeshift mode”, using short, homemade gutters made from metal sheets, hollow tree trunks or plastic bottles that route the water into 210 l-drums, tubs or bowls. We aimed to investigate the reasons for the differences in the RWH mode (conventional or makeshift) and explore what the different modes of RWH mean for some aspects of household water insecurity. Our analysis is based on ethnographic field work in rural uMvoti, including field observations, interviews, participant observation, and a household survey with 67 households. Field observations suggested that income, water access and type of housing all contribute in interrelated ways to the mode of RWH that rural households could practice. We triangulated these hypothesised relations statistically. Moreover, our statistical analysis yielded new hypotheses for further ethnographic field work and allowed us to quantify the strengths of the effects: the share of round huts has a much greater effect on RWH mode than household income. For upscaling RWH in rural areas, therefore, the specific water needs and housing types of households need to be considered. While some households may benefit from new drums and gutters that are tailored to their round huts, other households may need to transition to conventional RWH with large tanks, which requires at least one building with straight roofs. Certainly, makeshift RWH is less efficient than conventional RWH systems in terms of volume, but can be advantageous in terms of water quality and affordability. Presumably, makeshift RWH is prevalent in other parts of rural South Africa and should be considered in future RWH research. With regards to the methodological stance of our study, we propose the iteration of ethnographic field work and statistical modelling as a useful research process for learning about particular places.
Net acidification preserves phytoliths over a century in a bare fallow soil
Authors: Delvaux Bruno , Li Zimin
Published: February 2023

Acid soils cover approximately 40% of the world's land area and 50% of potential arable land. Net acidification is a natural process occurring wherever annual precipitation exceeds evapotranspiration. It can be accelerated or blocked by the use of fertilizers and amendments. Phytoliths are fine-sized biogenic silica particles that can either dissolve to contribute to the global cycle of silicon (Si) or persist in soils and sediments over millenniaHere, we study the resilience of phytoliths in a loess derived Luvisol maintained as a bare fallow for nearly one century (1929-2019). We compared a control with plots affected by the prolonged use of ammonium sulfate [(NH4)2SO4] or calcium carbonate [CaCO3]. A diachronic dynamic of the kinetic release of dissolved Si (DSi), aluminum (Al) and germanium (Ge) was carried out using a dilute saline solution. Molar Al/Si and Ge/Si ratios were used to identify the DSi source and pH was measured at each kinetic step. Phytolith content was assessed by heavy liquid separation. Extracted phytoliths were separated as not-, little- and highly-weathered by counting dissolution cavities per 100 µm2.Over the period 1929-2019, pH decreases from 6.0 to 5.7 with no input, from 6.0 to 3.5 under prolonged use of (NH4)2SO4, but increased from 6.0 to 8.5 under systematic liming with CaCO3. Using the total reserve in bases (TRB) as a proxy for the soil Acid Neutralizing Capacity (ANC), we observed that TRB was 110 cmol(+)kg-1 in 1929. TRB (cmol(+)kg-1) decreased to 94 and 84 with no input and (NH4)2SO4, respectively, while it increased to 160 with CaCO3 indicating, respectively: net acidification, accelerated net acidification and net alkalinization.Clay minerals and phytoliths were the privileged source of DSi under prolonged use of (NH4)2SO4 and CaCO3, respectively. Phytolith content was around 14 g kg-1 in 1929. It slightly decreased over a century with no input and CaCO3 supply, but not under prolonged use of (NH4)2SO4. In addition, the proportions of not-little-highly weathered phytoliths were 26-36-38 % with no input, 21-37-42% with CaCO3 and 42-33-25% with (NH4)2SO4 indicating a better resilience of phytoliths under accelerated acidification.