bluuebunny/crossref_metadata_2025 huggingface dataset:
Gravity applications enabled by quantum sensors. Perspectives for the FIQUgS project.
Authors: Capponi Martina , Sampietro Daniele , Jacob Thomas , Janvier Camille
Published: February 2023

The measurement of gravity acceleration and of its variations are commonly used by geophysicists in many Earth sciences applications. It is quite well known that gravity at the surface of the Earth is influenced by the masses surrounding the instrument, so its measurement can be exploited to characterize subsurface mass density distribution and to investigate many phenomena related to the Earth lithosphere. Gravity measurements also contribute to the exploration of underground resources (mining, hydrology, oil & gas) as well as to civil engineering activities with the detection of voids and cavities. Quantum gravity sensors have already demonstrated interesting competitive advantages with respect to classical gravimeters since they can measure the field with a higher accuracy and they allow to perform absolute measurements. In the framework of FIQUgS project, funded by the European commission in 2022, a new generation of quantum gravity sensors (QGs) is under development to overcome the barriers limiting the first-generation sensors operational usage (e.g. the transportability and robustness not suitable for outdoor operations). Within the project, a new Absolute Quantum Gravimeter (AQGs) and a Differential Quantum Gravimeter (DQGs) are foreseen to allow not only on field absolute gravity measurements but also measures of the vertical derivative.In the context of the FIQUgS project a wide review of potential use cases for quantum gravity sensors has been performed. Applications, which benefits from the advantages of the next generation QGs, have been identified, within different market sectors. Different scenarios have been considered and by means of specific synthetic simulations the capabilities of this technology have been assessed.The potential applications for QGs investigated can be divided in two macro-sectors: the first one includes all the static applications that aim at retrieving the density distribution within a certain area to distinguish any kind of target (e.g. geological models for mining exploration, voids and cavities detection, archeological applications…). The second sector includes dynamic, or the so-called time variable applications which are instead focused on analyzing the temporal variability of potential field signals linked to mass changes (e.g. monitoring of CCS, hydrology variations etc.). For each of the identified scenarios a simulation has been set, which means to build a synthetic model of the study area and analyze its effect in terms of gravity supposing different hypothesis and background information.The results of this analysis will be here presented showing potentialities of quantum sensors and advantages of this next generation of instruments for geophysics applications.
A sub-seasonal to seasonal prediction system with MPI-ESM
Authors: Koul Vimal , Brune Sebastian , Febre Cristian , Domeisen Daniela I.V. , Baehr Johanna
Published: February 2023

Current sub-seasonal prediction systems are traditionally based on models developed for numerical weather prediction. We present a different approach wherein we develop a sub-seasonal prediction system using a coupled Earth system model, the Max-Planck-Institute Earth system model (MPI-ESM), developed primarily for the use in climate prediction. We present results from initialized sub-seasonal reforecasts for the time period 1993-2017 from a 1st generation (CMIP5) seasonal-turned-sub-seasonal prediction system based on MPI-ESM including different components of the Earth system: atmosphere, land surface, ocean, and marine ecosystems. With our system we find (1) that atmospheric variables can be predicted with a quality and prediction horizon similar to what is found within the range of current sub-seasonal to seasonal prediction systems, (2) that extreme events as diverse as heatwaves over land, storm severity over Europe, and sudden stratospheric warmings can be skilfully predicted one to a few weeks ahead, (3) that sea surface temperatures can be skilfully predicted in the majority of large marine ecosystems for several weeks ahead, and (4) that sea ice area in the majority of Arctic seas can be skillfully predicted several weeks ahead. Our findings indicate that a coupled Earth system model like MPI-ESM can already be seamlessly used for sub-seasonal to seasonal (to decadal) climate predictions of different domains of the Earth system. Ultimately these results ask for the seamless approach to be embedded into the development of future coupled Earth system models.
Comparison of nitrogen use efficiency of manure and inorganic fertilizer based on long term field trials in Hungary
Authors: Pirkó Béla , Bakacsi Zsófia , Tóth Eszter , Szabó Anita , Arendás Tamás , Csathó Péter
Published: February 2023

Sustainability cannot be achieved without improving soil conditions. However, it is estimated that between 60 and 70% of EU soils are unhealthy. Thoughtful use of exogenous organic matter can help restore soil functions and thus improve soil health. Animal manures are the most abundant organic matter in agriculture and, in addition to their high nutrient content, they contribute to improving soil health in many ways by increasing soil biological activity. For these reasons, their efficient and environmentally friendly use is of major importance.The TUdi project will contribute to develop healthy and productive agricultural ecosystems, where the organic fertilizers play an important role in the nutrient supply of the plants. The ongoing development of the nutrient management tool has to consider the different behavior and characteristic of these materials. Our study gives an example of how the long term field trials results can be implemented in this process.37 trials have been selected from the database of the Hungarian field trials which contain the effects of farmyard manure and mineral fertilizer application on the basis of NPK nutrient equivalence. Among the various treatments, the yields of the absolute control, the farmyard manure treatment and the one with equivalent amounts of NPK in the form of mineral fertilizer were evaluated. The experiments were grouped according to the soil texture.Annual fertilization was more favourable in all cases than periodic manure application. Differences between yield surpluses declined with an increase of soil clay contents. The efficiency of fertilization in both farmyard manure and fertilizer treatments were higher on sandy soils, which have the poorest natural nutrient supplying capacity.The correlation between the changes in the organic matter (OM) content of the control plots soils, and differences of the responses to nutrient applied can be described by hyperbolic functions. A similar correlation was established between the AL—(ammonium lactate) soluble K contents and differences of the responses to farmyard manure and fertilizer.As the values of these two soil parameters increased, the advantage of the nutrients given in the form of fertilizer over farmyard manure declined. Keywords: long term field trial, manure application, fertilization, nitrogen use efficiency, nutrient advisory system 
A novel Laser-based technique for in-situ automated measurements of atmospheric CH4 isotopologues and implications for current and future emission scenarios
Authors: Safi Emmal , Rennick Chris , Chung Ed , Arnold Tim
Published: February 2023

Methane (CH4) is the second strongest anthropogenic greenhouse gas in terms of radiative forcing after carbon dioxide (CO2). It has a relatively short atmospheric lifetime for a greenhouse gas (~9 years)and so is an attractive target for near-term climate mitigation strategies. While the total amount fraction of atmospheric CH4 is currently measured by atmospheric monitoring stations to calculate global and regional budgets, it is not currently possible to distinguish the total amount of CH4 emitted by individual sectors. Different sources emit CH4 with unique isotope ratios, and so continuous isotope ratio measurements have the potential to provide the data needed to disaggregate emissions sources.  

We have developed Boreas, an automated field deployable CH4 preconcentrator coupled to a laser spectrometer able to provide continuous, high frequency measurements of both δ 13C (CH4) and δ 2H (CH4) and the total CH4 amount fraction in ambient air. Boreas was deployed to a UK atmospheric monitoring site located in Heathfield, East Sussex, in May 2021.  

We compare atmospheric measurements of δ13C(CH4) and δ2H(CH4) made from Spring 2021 to Spring 2023 with equivalent model output and analyse similarities and differences in the context of currently known isotopic source signatures in Europe. We also consider potential future CH4 emission scenarios and show how these measurements could be used under future emission reduction strategies. 
Impact of Local Ties in GNSS and VLBI Integrated Solution
Authors: Wang Jungang , Glaser Susanne , Ge Maorong , Balidakis Kyriakos , Heinkelmann Robert , Schuh Harald
Published: February 2023

In the multi-technique integrated solution, different space geodetic techniques are combined via common parameters and external observations, such as global ties (Earth Orientation Parameters, EOPs) and local ties (LTs), respectively. Local ties, which directly link the coordinates of co-location stations, are currently used in determining terrestrial reference frames (TRFs). We investigate the impact of global and local ties in Global Navigation Satellite Systems (GNSSs) and Very Long Baseline Interferometry (VLBI) integrated solutions in five VLBI continuous (CONT) campaigns. Compared to a baseline solution where GNSS and VLBI have separate minimal constraints implemented (no-net-rotation and no-net-translation, NNR+NNT), applying additional GTs and LTs improves the VLBI TRF and EOP estimates. As LTs are supposed to transfer the datum information between GNSS and VLBI, we further investigate the scenario where the VLBI datum is linked to GNSS via LT, without NNR+NNT applied to the VLBI network. We demonstrate that in this scenario the VLBI solution is deteriorated, especially the east-west component of station coordinates and UT1-UTC estimates, mainly due to the insufficient accuracy of the currently used LTs. We thus emphasize the importance of improving the accuracy of LT measurements and applying additional ties, for example, space ties and atmospheric ties.
Nature-based Restoration Planning using Spatial-Temporal Simulation Modeling
Authors: Song kihwan , Chon Jinhyung
Published: February 2023

Natural hazards such as typhoons and earthquakes caused by climate change cause enormous damage to the social-ecological system and result in the degradation of ecosystem services. This has suggested the necessity of considering the concept of resilience along with the limitations of existing methods in disaster management and has been linked to restoration plans connected to nature-based solutions. The Republic of Korea suffers from natural disasters caused by typhoons and torrential rains every summer and the damage is worsened because of insufficient spatial management and the failure to predict disasters. Therefore, to cope with these damages and maintain ecosystem services, a nature-based restoration plan should be presented using the concept of resilience. In the process, it is necessary to understand the changes that have happened in ecosystem services over time and plan a space that can respond to natural disasters. The purpose of this study is to simulate changes in ecosystem services for natural disaster damage through spatial-temporal models and present the improvement effects of ecosystem services through nature-based restoration scenarios. Accordingly, we first searched for areas to which the resilient ecosystem service restoration planning could be applied within Pohang, which suffered significant flood damage throughout 2022. Then, a spatial-temporal model of the target area was constructed to simulate changes in the ecosystem services due to floods. Finally, the ecosystem service improvement effect of the spatial-temporal simulation model was analyzed by constructing and applying a nature-based restoration scenario. Based on the results of this study, a nature-based restoration plan was conceived of as a method to improve ecosystem services for the long term by simulating changes in the target area affected by natural disasters in terms of time and space. In addition, by presenting the preceding process as a nature-based restoration plan, it is possible to maintain resilience to the damage caused by natural disasters in terms of the social-ecological system.This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education(NRF-2021R1A6A3A01087973). This research was also supported by OJEong Resilience Institute (OJERI).
Effects of near-surface atmospheric stability and turbulence on air pollution levels in Madrid
Authors: Ortiz-Corral Pablo , Román-Cascón Carlos , Serrano Encarna , Sastre Mariano , Maqueda Gregorio , Yagüe Carlos
Published: February 2023

Air pollution is one of the main hazards for human health worldwide, especially in cities. Surface emissions are the main responsible for the presence of pollutants in the near atmosphere, but meteorological conditions typically play a fundamental role in their accumulation or dispersion. In this work, we focus on the near-surface atmospheric stability and turbulence, for which data from four field campaigns with meteorological and pollutant measurements belonging to the AIRTEC-CM project(*) have been analysed. Available data correspond to the winter and summer seasons of 2020 and 2021 at two public sites located in the city centre of Madrid: a University (ETSII) and a Hospital (HCSC). The evolution of turbulence and stability and their relationships with pollutants such as NO2, PM2,5 and PM10 are investigated. To study turbulence, an analysis of friction velocity and turbulent kinetic velocity is carried out, while the stability parameter (Obukhov length) and the Richardson number obtained by means of the simplified universal similarity functions have been considered for the analysis of the stability. Through the analysis of the mean daily cycle of pollutants, it has been observed how its evolution shows two maxima centered on the morning and evening transitions. The results obtained indicate that pollutant concentrations are strongly influenced by the daily cycle of stability and turbulence, marked by the presence of a maximum of turbulence in the central hours of the day (when the sensible heat flux is greater) and a strong decay of this in the day-night transitions, which in the case of the afternoon transition coincides with the shift from the convective to the stable boundary layer. In addition, the time when this turbulence decay occurs modulates the pollutant concentration values reached, added to the intensity of the stability itself. (*) AIRTEC-CM research project (S2018/EMT-4329) is funded by The Regional Government of Madrid (Spain) and the European Union.
Clusters of lava fountain events identified on strainmeter data at Etna volcano
Authors: Carleo Luigi , Currenti Gilda , Bonaccorso Alessandro
Published: February 2023

Lava fountains at Etna volcano are spectacular eruptive events characterized by powerful gas jets that expel lava fragments to several hundred meters and volcanic ash to several kilometers above the crater. Ash fall-out and dispersal cause critical hazards to both the vehicular traffic and the aviation, inducing the temporary closure of the southern Italy airports.In 2020-2022, Etna experienced more than 60 lava fountains. The dynamics of such explosive events is usually a gradual process, starting with a strombolian activity that progressively evolves in an intense and continuous explosive activity with a sustained eruptive column. The duration, the degree of explosiveness, the portion of effusive flows, etc., are usually variable implying a different degree of involved hazard. Recently, researchers attempted to manually classify lava fountains at Etna on the basis of volcanological and geophysical data. However, manual classification is time consuming and prone to subjective biases.We propose an automatic procedure to cluster the lava fountain events that occurred in 2020-2022 at Etna using unsupervised machine learning techniques. The clustering algorithm is applied on high precision strain signals recorded by the borehole dilatometer network deployed to monitor volcano deformation processes. In particular, the analysis focuses on the strain variations recorded during the lava fountain events to highlight similarities and differences among the eruptions in terms of induced ground deformation. The results disclose the main features of the strain signal effective to group the lava fountain events. Four well-separated and coherent clusters are identified improving the manual classifications performed by the experts. Moreover, the analysis reveals that the lava fountains clusters are grouped also over time showing possible transitions in the eruptive style.
Post-collision Extension in the Eastern Central Asian Orogenic Belt: Insight from the Late Triassic High-Mg Andesites
Authors: Zhang Liying , Huang Feng , Xu Jifeng , Liu Xijun
Published: February 2023

Central Asian Orogenic Belt (CAOB) with multiple blocks and suture zones is a key locality for understanding the process of plate tectonics. Extensive studies are mainly on the western CAOB, but less on the eastern side. Many questions remain unclear due to the lack of obvious structural records and ophiolite assemblages. In this study, we report the andesites sampled from Laolongtou Formation in the eastern CAOB with detailed geochronology and geochemistry analyses. The andesites are characterized by high Mg# values at their intermediate SiO2 contents, which are defined as typical high Mg# andesites. Zircon U-Pb ages show they erupted at the Late Triassic (~236 Ma) and the Ti-in-zircon thermometer indicates a potential high primary magma temperature. Geochemically, they show relatively high contents of Al2O3, Na2O, Cr, and Ni, with enrichment in light rare earth elements and depletion in high field strength elements. Besides, they are markedly depleted in Nb and Ta, enriched in Sr, Ba contents, and significantly differentiated in Th and U contents. They have homogeneous depleted Sr-Nd isotopic compositions that fall into the range of MORB and mantle-derived ranges. Together with the depleted zircon Hf isotopic compositions, showing the possible addition of a hot and depleted component. We propose that they were formed by interactions of components derived from a subducting slab and the overlying mantle wedge. The slab-derived components are most likely a low degree of partial melting of subducted oceanic crust that was able to stabilize garnet and rutile, without plagioclase in the melt residue. They subsequently interacted with the overlying mantle wedge, which resulted from an post-collisional setting related to the final closure of Paleo-Asian Ocean. The upwelling of the upper mantle triggered by the oceanic slab break-off may explain the genesis of the high Mg# andesites and the formation of the continental crust in northeast China. 
Cosmic rays on snow: A combined analysis of fractional snow cover derived from Sentinel-2, MODIS and Cosmic Ray Neutron Sensors across Europe
Authors: Krebs Nora , Schattan Paul , Oswald Sascha , Schrön Martin , Rutzinger Martin , Stötter Johann
Published: February 2023

Epithermal neutrons from cosmic ray showers are slowed by hydrogen atoms in snow. The drop in the fast neutron abundance in the atmosphere can be measured with above-ground Cosmic Ray Neutron Sensing (CRNS), allowing for an estimation of the Snow Water Equivalent (SWE). SWE is an important variable that has a substantial role in hydrological modelling and forecasts. However, up to now, SWE is conventionally measured at point-scale, which holds only little information about the average SWE in areas of heterogeneous terrain and where snow drift is a predominant process. CRNS offers the prospect of closing this gap by sensing neutrons within a footprint of 10–20 hectares. Currently, further investigations are needed to reduce the uncertainties in the signal conversion from neutron counts to SWE. In this study, we compare the daily signals of 65 CRNS stations across Europe with the corresponding Fractional Snow Cover (FSC) products from Sentinel-2 and MODIS (Moderate-resolution Imaging Spectroradiometer) with a 20 m and 500 m spatial resolution, respectively. By analysing the FSC products, we were able to identify characteristic ranges of neutron counts at snow presence (winter signals) and absence (summer signals). Comparing these ranges and their overlap among stations, we were able to distinguish typical signal properties of lowland, pre-Alpine and Alpine sites. We found that altitude-related properties, such as soil and vegetation characteristics govern the general neutron level at the study sites. Snowfall typically leads to a major drop in the neutron count rate that is superimposed on the summer neutron count level. High-altitude stations are generally characterized by low ranges of count rates in summer and by high ranges in winter, while low-altitude stations show a reversed trend. Our results demonstrate that the suitability of a station for SWE measurements with CRNS depends highly on the site-specific hydrogen pool fluctuations that can be linked to altitude. Especially in heterogeneous mountain terrain with low soil formation, the advantages of CRNS come into play and can provide a spatial average of SWE with low uncertainties.
The influence of warm weather and outdoor environment design on preschooler’s physical activities and thermal comfort
Authors: Wallenberg Nils , Lindberg Fredrik , Thorsson Sofia , Bäcklin Oskar , Rayner David , Raustorp Anders , Jungmalm Jonatan , Fröberg Andreas
Published: February 2023

Warm weather can have negative effects on the health and wellbeing of humans, especially risk groups e.g. children. Methods for estimating thermal comfort and physiological stress outdoors are not developed or adjusted for children. A consequence of this is few existing studies on children and thermal comfort and heat stress, particularly in a Swedish context. Children are at higher risk of heat stress than adults because of a larger body-surface-area to body-mass-ratio, lower sweat rate and that they are less aware of their thermal status. Swedish children attending preschool spend around three hours per day outdoors and the effects of weather and outdoor environment design on children’s thermal comfort are not clear. By better understanding how weather affects children's thermal comfort, measures can be taken to reduce heat stress and increase children's health and wellbeing.

Here we present results from a project on the effect of warm weather on Swedish preschooler’s health and wellbeing. The results are based on detailed observations and simulations for present day climate as well as future climate change scenarios and give indications on exposure to heat stress and potential implications on the health and wellbeing of the children. For example, two thirds of preschool yards in Gothenburg are exposed to strong heat stress on clear and warm days. Strong heat stress have negative consequences for the pedagogic activities and wellbeing. Moreover, days with strong heat stress will increase in the future in exposed yards, whereas yards with sufficient shade are less prone to heat stress.
No evidence of spatial feedbacks causing convective clustering in the Tropical Western Pacific
Authors: Casallas Alejandro , Tompkins Adrian , De Vera Michie
Published: February 2023

Idealized high-resolution models show spontaneous aggregation of tropical convection on the beta-mesoscale driven by radiative feedbacks, and the resulting drying implies a potentially important impact on climate sensitivity missing in classic convective parameterization schemes. Here, we combine multiple state-of-the-art observations and reanalysis of the tropical atmosphere and ocean in a 1000 x 700 km region in the tropical Western Pacific warm pool region, along with numerical models and machine learning techniques to demonstrate that in boreal summer, while radiative and surface fluxes act to cluster convection, the convection remains in a random configuration as evidenced by very limited spatial variability in total column humidity. Instead, in the winter/spring period, when the warm pool is displaced southwards, the region lies on the warm pool boundary with stronger north-south surface temperature gradients. Convection usually remains strongly organized in these periods but is interspersed with occasional random episodes. This entails a sudden flipping into the random state associated with the southerly flow anomalies that advect convection and humidity over the cooler sea surface temperature (SST) regions. Observations and models suggest that this advection of humidity is the principal driver of organization and disorganization of convection and that diabatic feedbacks instead always act to try and cluster convection. Results also indicate that when convection is organized, the atmosphere is significantly drier than when convection is random and that the Longwave (LW) clear-sky top of atmosphere flux is significantly larger in the organized state, principally due to the moisture differences between both configurations. The LW all-sky flux difference between both states is less significant compared to the LW clear-sky because it is largely driven by the cloud cover, which, although smaller for the organized state, does not differ significantly. These differences between organized and random convective states, and the role of the diabatic processes in providing forcing for aggregation, mostly reproduce the findings of idealized models. However, this study indicates that in the real tropical atmosphere diabatic forcing is inadequate to lead to aggregation on its own over homogeneous SSTs, and instead, spatial SST gradients and large-scale dynamics are key to driving aggregation and determining its breakup over the warm pool region.
Geophysical and geological evidence of a previously undetected NW-trending fault crossing the historical centre of Messina (Sicily, south Italy)
Authors: Scolaro Silvia , Pino Paolo , Torre Antonino , D'Amico Sebastiano , Neri Giancarlo , Presti Debora
Published: February 2023

Extensive ambient noise measurements have been carried out in the historical centre of Messina (Sicily, South Italy) and the related HVSR results showed a clear variation of the fundamental peak frequency in the range between 0.4 Hz and 1.6 Hz. This frequency variation is detected across a NW-SE segment, and it can be imputed to a strong lateral heterogeneity of the sediment cover going from southwest to northeast of the study area. Moreover, we carried out a detailed geological field survey and analysis of land surface morphology based on topographic maps and DTM data that allowed us to detect the NW-trending fault, never documented in literature, crossing the historical centre of Messina. Geologic observations indicate clearly normal faulting and activity of this fault is documented at least until Middle Pleistocene, with likely prosecution during Upper Pleistocene.The detected NW-trending fault is roughly perpendicular to the strike of the main structural system of the Straits of Messina framework to which the major earthquake of 1908 (M 7.1) is imputed. Therefore, deeper future investigations for appropriate framing into the local geodynamic context and for evaluation of its eventual prosecution in the offshore area are necessary.In this preliminary study we identify structural discontinuities and faults which may represent new sources of hazard in a town exposed to very high seismic risk in Italy.
Influence of mechanical stratigraphy and structural inheritance on the geometrical evolution of normal faults in the German Molasse Basin
Authors: Shipilin Vladimir , Tanner David , Ziesch Jennifer , Buness Hermann
Published: February 2023

Lithospheric flexure is the primary mechanism for the development of normal faults in foreland basins. While the tectonic regime defines the overall fabric of such flexure-induced faults, mechanical heterogeneity of the sedimentary sequence and pre-existing faults exert a major control on the geometry of the individual faults. Interpretation of 3-D seismic reflection data in the central part of the German Molasse Basin, a northern Alpine foreland basin, reveals a normal fault network that exhibits varying degrees of vertical segmentation. Two major faults oriented parallel to the strike of the Alpine orogen are characterised by geometrically coherent displacement of deeper Mesozoic strata and shallower Cenozoic strata. In contrast, another major fault system, oriented obliquely to the orogenic strike, shows an along-strike variation in geometric coupling between deeper and shallower structural levels. Although a thoroughgoing fault in the northeast, it bifurcates laterally to the southwest, with the deep and shallow segments decoupling across a southeastwardly-thickening, mechanically-weak layer. To establish the geometric evolution of these faults and understand to what extent it was governed by mechanical stratigraphy and structural inheritance, we here analyse throw distribution on the faults and variations in stratal thicknesses across the faults. High-resolution throw mapping indicates a general updip decrease in throw for the orogen-parallel faults, whereas the obliquely-oriented fault, in its coupled portion, has two throw maxima separated by a throw minimum at the mechanically incompetent interval. These results, together with syn-kinematic strata observations, show that the former faults initiated with the onset of the Cenozoic foreland flexure and grew upward by radial propagation, whereas the latter fault formed by an oblique reactivation of precursory Mesozoic faults and developed in the Cenozoic as a segmented structure. We hypothesise that the coupling of its deep and shallow segments to the northeast was established by a dip-linkage mechanism, which was inhibited further to the southeast as the mechanical barrier thickens. The reactivation of the pre-existing structures explains the non-optimal orientation of the younger fault segments at a shallower level, with the former acting as kinematic attractors for the latter faults. This study demonstrates how a detailed fault kinematic analysis can help to decipher the effect of multi-layered mechanical stratigraphy and structural inheritance on the spatial evolution of individual flexure-induced faults.
Earthworms as double-edged swords for organic matter turnover from forest floor to mineral soil – a mesocosm experiment with labeled beech litter
Authors: de Jong Philipp , Schleppi Patrick , Hagedorn Frank
Published: February 2023

Earthworms may act as double-edged swords for soil organic matter (SOM). While they can enhance organic matter (OM) mineralization via increased microbial activity they can also elevate OM stabilization in aggregates as particulate or mineral-associated OM. In this study, we will test this potentially opposing impact in beech (Fagus sylvatica L.) forests on limestone, a forest ecosystem with particularly high earthworm activity. A specific focus will be on OM transformation along the continuum from the forest floor (O horizons) to mineral soil (A horizons). The forest floor can represent a substantial OM-pool which is an important source for SOM formation via bioturbation or leaching but can be vulnerable to alterations due to climate change. In an extended lab mesocosm experiment, we will incubate local earthworm species in soil columns consisting of O and A horizons from four beech forest sites along an elevation gradient from 550 to 1250 m in the Swiss Jura Mountain range. Along this gradient, the dominating forest floor type is mull with its thickness increasing with altitude. We will establish the following three treatments (1) control with soil and unlabeled litter, (2) with soil and labeled litter and (3) with soil, labeled litter, and earthworms. For this setup, the Ol horizon will be replaced with beech litter highly enriched with 13C, 15N, and 2H. Soil respiration (CO2) and leaching (C, N, and H in dissolved OM) will be repeatedly measured. Our setup will allow for a separation of fluxes from the O horizons and the A Horizon. After approximately 4, 7, and 10 months each, a subset of mesocosms will be harvested to investigate isotope enrichment in earthworm biomass, earthworm casts, physical soil fractions, PLFAs, and microbial necromass. This will allow us to establish a mass balance of beech litter turnover as affected by earthworms for a time scale representative of one vegetation period. Fluxes of unlabeled OM will inform on the fate of inherent SOM. We expect that (1) following an initial colonization phase, earthworms will stimulate labeled litter mineralization and enhance litter transfer to aggregate fractions while not affecting the total SOM stock. (2) In the long term, less of the labeled material will be mineralized and more SOM stabilized in aggregate fractions will be recycled.
Atmospheric Analysis in the 1810s by Assimilating Diary-based Weather Category
Authors: Wang Xiaoxing , Toride Kinya , Ichino Mika , Yoshimura Kei
Published: February 2023

Daily atmospheric conditions before 1900 have been rarely investigated due to the limited availability of instrumental meteorological records. The documentary evidence is an alternative source that archives the atmospheric state. In Japan, the Historical Weather Database (HWDB, accessible by: http://tk2-202-10627.vs.sakura.ne.jp) provides descriptive daily weather information recorded in diaries at many stations since the 1660s. We utilize data assimilation to achieve high-temporal reconstructions by optimally combining observations with climate model forecasts. This study reconstructs daily weather conditions in the 1810s by assimilating diary weather information for the first time. We first categorize the descriptive records into “sunny”, “cloudy”, and “rainy”, and then assimilate these diary-based weather categories into the Global Spectral Model (GSM) through a local ensemble transform Kalman filter (LETKF) scheme. The reconstructed precipitation corresponds well with the daily synoptic pattern illustrated by documentary evidence in Japan. In a single-day case in August, 80% of non-assimilated diary categories are consistent with precipitation results. The atmospheric characteristics are also well reproduced in the Meiyu-Baiu season. Our results show better accuracy than the Twentieth Century Reanalysis (20CR) dataset due to their weak constraint in the Japan region. In addition, the Tambora eruption in April 1815 was among the largest in recent history, leading to the temperature decrease in Europe in the following year, commonly known as the “Year Without a Summer”. In our results, the surface air temperature anomaly indicates significant cooling also occurred in Japan in the summer of 1816, demonstrating the climate response to the Tambora eruption. This study shows the capability of diary data assimilation to reproduce daily atmospheric conditions, providing the basis to understand the cause of short-term variability in the past climate.
Semi-automated fault extraction and quantitative structural analysis from DEM data, a comprehensive tool for fault network analysis
Authors: Gayrin Pauline , Wrona Thilo , Brune Sascha
Published: February 2023

Mapping and characterisation of crustal faults represent one of the contemporary challenges for both tectonic understanding and seismic hazard assessment. Given the high resolution of satellite-derived digital elevation models and remote-sensing imagery, the development of an automatic method of fault extraction is a critical turning point. Here we present a Python-based, open-source workflow,  which is able to extract and characterize individual faults as well as entire fault networks from various datasets. Our workflow consists of four main steps: (1) The DEM contains different types of noise, which we reduce using Gaussian smoothing. (2) Then we use the Canny edge detection to highlight topographic discontinuities, such as faults. (3) These edges are simplified in single pixel-wide lines through the skeletonization algorithm. (4) Finally, we create a network consisting of nodes and edges from this skeleton. After a few post-processing steps we obtain a fault network of the sample area. We use the toolbox to study faulting in the East African Rift system, especially the Magadi Natron basin. The workflow was applied to a TanDEM-X digital elevation model with 12 m horizontal resolution and the Copernicus GLO-30 dataset with 30 m average horizontal resolution. The strike analysis shows four main directions from distinct fault populations. Moreover, we derive the fault displacement distribution throughout the basin, which allows us to calculate the total orthogonal extension of each geological unit and to compute the overall amount of extension of the region during geologically recent times.Our workflow is designed to evaluate topographic data of target sites in nature, it can, however, also be used to analyze analogue models and numerical simulations. To this aim, specific functions can be added in a modular way to suit the particularity of the area and of available data types. This workflow allows us to imagine a very wide range of applications and subjects of interest.
Mitigating Temporal Aliasing Effects by the Space-Wise Approach for Quantum Gravimetry Missions
Authors: Koç Öykü , Reguzzoni Mirko , Rossi Lorenzo , Migliaccio Federica
Published: February 2023

The aliasing problem in gravity field recovery arises from the under-sampling of geophysical signals which have a period less than twice the sampling period of the mission. This temporal aliasing problem matters even more for future gravity missions when assessing the actual improvement provided by using new technologies such as cold atom gradiometers or flying drag-free with a laser interferometer. The level of errors caused by temporal aliasing is significantly higher than these instrument errors. This indicates that to see any sort of improvement in time-variable gravity field recovery from quantum technologies, the aliasing problem must be overcome first.In this study, we propose a way of mitigating temporal aliasing effects by the space-wise approach. This approach consists of first estimating the very long wavelengths by some global technique (e.g., a least-squares adjustment) and then using this estimation to reduce filtered gravity gradients. A modification considering the short-term variations in the time-variable signal is here introduced into the filtering procedure. Later, the computed residuals are processed by a local collocation gridding procedure with the aim of improving the solution, especially for the shorter wavelengths. The signal covariance function estimation required for the gridding is here modified to account for the time variable signal.The data analysis based on the newly modified mathematical model is applied for the monthly time-variable gravity field retrieval by performing simulations over half a year time span. This is done along with the static gravity field estimation with the aim of evaluating the possible overall improvement coming from the use of quantum gradiometers.
Riverine water chemistry and rock weathering processes of Qingyi River basin, a subtropical basin in east China
Authors: Huang Xin , Pan Tianshuo , Cao Mingda , Zhang Jie , Zhang Zhixin
Published: February 2023

To investigate the rock weathering processes in silicate-dominated subtropical basin in east China, we analyzed major ion compositions of rivers and precipitation samples in the Qingyi River basin in the lower reaches of the Yangtze River. In this study, the characteristics of weathering processes in the Qingyi River basin were identified, and the rock weathering rates and consumption rates of atmospheric CO2 were estimated based on water chemistry and the forward model. The results showed that the anthropogenic influences on rock weathering was not significant, which means the rock weathering in the study area was mainly induced by carbonic acid while the influence of sulfuric acid and nitric acid could be neglected. The cations of rivers were mainly contributed by weathering of carbonates (59.2%), followed by weathering of silicates (17.9%). Atmospheric precipitation and evaporites contributed 9.6% and 5.6%, respectively. Spatially, the carbonate weathering rates and silicate weathering rates decreased as order of tributary Huishui river in the upstream mountainous areas (32.04 t·km-2·a-1 and 20.97 t·km-2·a-1) > main stream of Qingyi river (24.12 t·km-2·a-1 and 8.91 t·km-2·a-1) > tributary Zhanghe river in the downstream areas (13.68 t·km-2·a-1 and 2.85 t·km-2·a-1). Similarly, the CO2 consumption rates from carbonates weathering and silicate weathering followed the order of tributary Huishui river (5.86×105·mol·km-2 a-1 and 3.29×105·mol·km-2 a-1) > main stream of Qingyi river (2.45×105·mol·km-2 a-1 and 2.43×105·mol·km-2 a-1) > tributary Zhanghe river (0.77×105·mol·km-2 a-1 and1.39×105·mol·km-2 a-1). In conclusion, carbonate weathering induced by carbonic acid was dominant in the Qingyi River basin, with chemical weathering rates slightly lower than similar silicate-dominated subtropical basins in east China. The rock weathering rates in the study area differed spatially. In particular, silicate weathering in upstream mountainous areas accounted for more carbon sink of the whole Qingyi River basin, which is of great importance for the regional carbon cycle.Key words: subtropical; Qingyi River basin; rock weathering; atmospheric CO2 consumption; carbon sink
Implementation of sulfur hexafluoride (SF6) in the Belgian Assimilation System for Chemical ObsErvations (BASCOE)
Authors: Vervalcke Sarah , Chabrillat Simon , Minganti Daniele , Errera Quentin
Published: February 2023

Sulfur hexafluoride (SF6) is a greenhouse gas that is emitted at the surface because of its use as an insulator in electrical transmission equipment and electronic devices. Since its quasi-linear emission growth and its very long lifetime, SF6 can be used as a tracer for the Age of Air (AoA) to diagnose changes in the Brewer Dobson Circulation (BDC). The chemistry of SF6 has been implemented in the Chemistry Transport Model (CTM) of the Belgian Assimilation System for Chemical ObsErvations (BASCOE). Reaction rates were taken from previous studies while an electron density has been taken from WACCM-X-SD simulations.In this contribution, BASCOE-CTM simulations driven by ERA5 and MERRA2 will be discussed considering SF6 with and without mesospheric sinks (i.e. passive SF6 in the latter case). During the course of the simulations, the computed mixing ratios have also been saved in the space of MIPAS observations to analyse the impact of the MIPAS sampling in its AoA derivation.
Annual to seasonal glacier mass balance in High Mountain Asia derived from Pléiades stereo images: examples from the Pamir and the Tibetan Plateau
Authors: Bolch Tobias , Falaschi Daniel , Bhattacharya Atanu , Huang Lei , King Owen
Published: February 2023

Glaciers are crucial sources of freshwater in particular for the arid lowlands surrounding High Mountain Asia. In order to better constrain glacio-hydrological models, annual, or even better, seasonal information about glacier mass changes is highly beneficial. In this study, we test the suitability of very high-resolution Pleiades DEMs to measure glacier-wide mass balance at annual and seasonal scales in two regions of High Mountain Asia (Muztagh Ata in Eastern Pamir and parts of Western Nyainqêntanglha, South-central Tibetan Plateau), where recent estimates have shown contrasting glacier behaviour. We find that the average annual mass balance in Muztagh Ata between 2020 and 2022 was -0.11 ±0.21 m w.e. a-1, suggesting the continuation of a recent phase of slight mass loss following a prolonged period of balanced mass budgets previously observed. The mean annual mass balance in Western Nyainqêntanglha for the same period was highly negative (-0.60 ±0.15 m w.e. a-1 on average), suggesting increased mass loss rates. The 2022 winter (+0.21 ±0.24 m w.e.) and summer (-0.31 ±0.15 m w.e.) mass budgets in Muztag Ata and Western Nyainqêntanglha (-0.04 ±0.27 m w.e. [winter]; -0.66 ±0.07 m w.e. [summer]) suggest winter and summer accumulation-type regimes, respectively. We support our findings by implementing a Sentinel-1–based Glacier Index to identify the firn and wet snow areas on glaciers and characterize accumulation type and demonstrate the potential of very high-resolution Pleiades data to monitor mass balance at short time scales and to improve our understanding of glacier accumulation regimes across High Mountain Asia.
Exploring practical citizen science in China
Authors: Zhou Xudong , Wan Luwen , Lin Jingyu , Shao Manqing , Feng Sifang , Zhang Beichen , Xu Yuanhao , Li Yuxin , Liu Yuan , Liu Ming , Wang Libo , Tan Xingyan
Published: February 2023

The development of citizen science is still at a very early stage in China. There are three primary reasons: 1. The government has strict data collection and sharing regulations. 2. There are very limited official leading groups, guidelines, and financial support on citizen science. 3. The public still lacks enthusiasm and basic training in citizen science. However, given the large population, increasing educational level of the society, and the help of new technologies, we can see a bright future for citizen science in China. We need to be prepared for that.Hydro90 is a bottom-to-top established scientific community within the field of hydrology and earth science. It shares the latest academic research, broadcasts latest news, and organizes lectures, webinars, and workshops. It aims to enhance the communication among scholars, and between scholars and the public, especially among the young ages. It has been run for almost three years, with around 20,000 followers on the social media platform. However, we are still exploring how to promote citizen science in China. We want to share our recent experiences and efforts to overcome the current barriers in citizen science in the EGU. We are also looking forward to the great suggestions from European communities.