bluuebunny/crossref_metadata_2025 huggingface dataset:
Extreme PM and ozone pollution over central Europe: interactions of the urban canopy meteorological forcing and radiative effects of urban emissions
Authors: Prieto Perez Alvaro Patricio , Huszar Peter , Karlicky Jan
Published: March 2022

Extreme air pollution in European cities, especially those in central and eastern Europe is, regardless of strict pollution control measures, still present, representing a large health burden on their inhabitants. Understanding the processes that control or modulate such events over urban areas is therefore crucial. In general, the climate-chemistry interactions over urban areas are complex with multiple feedbacks. In this study, based on two air pollution events with i) high winter PM concentrations and stagnant conditions (14 days in January 2017), ii) elevated ozone levels during a dry sunny summer period (14 days in August 2015), we will examine the mutual role of urban emissions (and secondary pollutants formed from them) and the urban canopy meteorological forcing (UCMF) over central Europe. We performed a series of WRF-Chem simulations with/without urban land-surface (effect of rural-urban transition) and with/without urban emissions, while six large central European cities were considered. Impact on both meteorological conditions and chemical species is examined.

Regarding the impact on meteorological conditions (temperature, windspeed, boundary layer height), we showed that the direct effect of UCMF (1-2K for temperature) is much larger than the secondary effects of the radiative impacts of urban emissions (driven mainly by aerosol effects; 0.1 K for temperature in average). It was also shown that these radiative impacts depend whether UCMF is included or not, with differences up to 2 K in hourly values. The impact on chemical concentrations is driven especially by UCMF causing decrease of PM and increase of ozone while the indirect effects of urban emissions induced meteorological changes are substantially smaller.

 
An ionospheric disturbance forecast model based on real-time solar wind analysis with the best-fitting historical storm events
Authors: Schmölter Erik , Berdermann Jens
Published: March 2022

A modeling approach for long time predictions (more than 12 h) of ionospheric disturbances driven by solar storm events is presented. Intended for an operational framework, this model shall deliver fast and precise localized warnings for these disturbances in the future. For this reason, a data base of historical solar storm impacts covering two solar cycles is used to reconstruct future events and resulting ionospheric disturbances. Here, we will present the basic components of the model and show first validation results based on predicted and observed geomagnetic activity, global total electron content and selected solar storms. Two storm events (including the St. Patrick’s Day geomagnetic storm during the 17 March 2015) are analyzed in more detail to illustrate the model capabilities. We will also discuss possible future improvements of the individual model parts, as well as the planned extensions and applications.
Monitoring long term seismic velocity changes in the Apennines region (ITALY)
Authors: Mikhael Nour , Poli Piero , Garambois Stephane
Published: March 2022

Continuous noise-based monitoring of seismic velocity variations in the Earth’s crust could reveal crucial information about some of its dynamic processes and has a versatile applications. We investigate temporal velocity variations (dv/v) to probe the physical properties of seismogenic fault volumes, in the central Appennines. We aim to gain new insights into the physics of earthquake cycles along with transient tectonic deformations and shed new light into the depth dependent rheology of the crust. We perform velocity variation measurements on seismic noise autocorrelations over a period of 13 years for several lapse time coda windows, using the wavelet transform approach. A Markov chain Monte Carlo approach is finally used for the retrieval of dv/v time series, with daily resolution, at each of the Italian seismic station. Our results capture the evolution of dv/v prior and after the 2009 Mw 6.3 L'Aquila earthquake, the 2016 – 2017 central Italy earthquake sequence and during aseismic deformation episodes. We further observe signatures of several other processes as water level variation in the crust and loading (releases) related with climatic forcings. The detailed analysis of our high-temporal resolution dv/v time series, combined with geodetic and other seismological observables, permits to quantitatively assess the pre- and post-seismic processes, and the changes of crustal properties during episodes of aseismic deformation in shallow normal faults. 
Partially interpretable neural networks for high-dimensional extreme quantile regression: With application to wildfires within the Mediterranean Basin
Authors: Richards Jordan , Huser Raphaël , Bevacqua Emanuele , Zscheischler Jakob
Published: March 2022

Quantile regression is a particularly powerful tool for modelling environmental data which exhibits spatio-temporal non-stationarity in its marginal behaviour. If our interest lies in quantifying risk associated with particularly extreme or rare weather events, we may want to estimate conditional quantiles that are outside the range of observable data; in these cases, it is practical to describe the data using some parametric extreme value model with its parameters represented as functions of predictor variables. Classical approaches for parametric extreme quantile regression use linear or additive relationships, and such approaches suffer in either their predictive capabilities or computational efficiency in high-dimensions. 

 

Neural networks can capture complex non-linear relationships between variables and scale well to high-dimensional predictor sets. Whilst they have been successfully applied in the context of fitting extreme value models, statisticians may choose to forego the use of neural networks as a result of their “black box" nature; although they facilitate highly accurate prediction, it is difficult to do statistical inference with neural networks as their outputs cannot readily be interpreted. Inspired by the recent focus in machine learning literature on “explainable AI”,  we propose a framework for performing extreme quantile regression using partially interpretable neural networks. Distribution parameters are represented as functions of predictors with three main components; a linear function, an additive function and a neural network that are applied separately to complementary subsets of predictors. The output from the linear and additive components is interpreted, whilst the neural network component contributes to the high prediction accuracy of our method.

We use our approach to estimate extreme quantiles and occurrence probabilities for wildfires occurring within a large spatial domain that encompasses the entirety of the Mediterranean Basin.

 
Breakdown energy scaling in a self-similar earthquake model
Authors: Kammer David , Ke Chun-Yu , McLaskey Gregory
Published: March 2022

During an earthquake, the elastic energy released from the Earth’s crust is partially radiated as seismic waves and partially dissipated along the tectonic fault. The dissipated energy can be divided into heat, which is produced by friction and other nonlinear mechanisms, and breakdown energy, which is associated with the dynamic weakening process of the fault. This breakdown energy is a key fault property as it directly affects nucleation, propagation and arrest of earthquake ruptures, and, hence, may control the size of an earthquake. However, the breakdown energy is difficult to measure directly on the fault and, therefore, it is routinely inferred from seismological measurements. A common observation is that the inferred breakdown energy, if positive-valued, scales with relative slip along the fault. In other words, larger earthquakes appear to dissipate more energy per unit rupture area through the weakening process, which typically occurs over very short slip distances. This would suggest that the earthquake rupture contains information about the final size of the earthquake starting from a very early stage of the earthquake, which is reasonably disputed in literature. In addition, the inferred breakdown energy is frequently observed to be negative-valued, which would violate thermodynamics. Therefore, we note that our current understanding of the seismologically inferred breakdown energy remains inconsistent. Here, we introduce a self-similar earthquake model that presents a similar scaling of the inferred breakdown energy despite constant and scale-independent fault properties (including the locally dissipated energy). We will show that the observed scaling is the result of a scale-invariant stress drop overshoot that distorts the global energy balance used for determining the breakdown energy. Therefore, our results suggest that the overall rupture mode – whether it is a crack-like or a pulse-like rupture – is a crucial factor for the inferred breakdown energy. Consequently, a pulse-like rupture, which is typically associated to stress drop undershoot, may explain the observed negative breakdown-energy values.
Micromagnetic modeling of a magnetic unstable zone and its geological significances
Authors: Wang Yuqin , Ge Kunpeng , Williams Wyn
Published: March 2022

Abstract

Recent micromagnetic simulations have found that particles in the size region of the single domain (SD) to single vortex (SV) transition zone are prone to poor thermal and field stabilities that could adversely affect the accuracy of interpretations of paleomagnetic recordings. In this study, we attempt to evaluate the internal magnetization characteristics of these magnetically unstable (MU) particles and the influence on paleomagnetic observations by simulating the magnetic behaviour of 68-104 nm truncated octahedral magnetite particles via the MERRILL modelling software. We found that: (i) The size region of the "MU zone" for grains of cubic octahedral shape is different with cubic octahedrons and spheres, indicating the zone may be controlled by the geometry and shape of particles; (ii) The MU zone has a range of 79-91 nm region, which is dominated by a hard-axis aligned single vortex (HSV); (iii) MU particles are unstable as a function of temperature. Finally, the numerical fitting of hysteresis parameters for experimental data suggests that the influence of such MU particles in samples cannot be ignored, especially for samples with fine-grained magnetic minerals as the primary magnetic recording carriers. This research has extended our understanding of the behaviour of the "MU zone" and its significance on paleomagnetic records.

 
2-D fully coupled morphodynamic modelling in vegetated environments based on the anisotropic porosity method
Authors: Li Wei , Liu Bingrun , Hu Peng
Published: March 2022

Previous studies for numerical representation of aquatic vegetation based on the isotropic porosity shallow water models can not only consider the effects of vegetation resistance and spatial occupation in physics, but also improve the computational efficiency in large-scale modelling. This type of models provides a promising tool to numerically study the vegetated flow and the corresponding sediment transport in practice. However, the characteristics of preferential flow among complex vegetation distributions which are often observed in nature cannot be well captured due to the isotropic assumption. Thus, we make an improvement by introducing the anisotropic porosity method in the shallow water model. Unlike the isotropic porosity method which uses only one porosity parameter to describe the vegetation spatial occupation, the anisotropic porosity method defines a cell-based porosity for volumetric occupation and an edge-based porosity for flux exchange to capture the flow heterogeneity in space. Under the framework of finite volume method, the model is solved explicitly with a hybrid LTS/GMaTS method and the Open MP techniques for fast modelling. The well-balanced property and accuracy of the developed model have been tested by a series of flume experiments with different vegetation distributions over fixed or mobile beds. In general, both velocity and deposition patterns are well reproduced. It shows that a constant vegetation drag coefficient can lead to numerical solutions of comparable accuracy as those complex empirical relations in the anisotropic porosity modelling. In addition, the stem-scale turbulence could be a critical factor affecting the sediment transport inside and around vegetation patches and its appropriate quantification in the shallow water modelling deserves further research.
Regional winds over the Iberian Peninsula (Cierzo, Levante and Poniente) from high resolution COSMO-REA6 reanalysis
Authors: Ortega María , Sánchez Enrique , Gutiérrez Claudia , Molina María Ofelia
Published: March 2022

Regional winds are usually caused by small pressure differences, and so air flows arise in very specific areas. When these air flows pass through certain orographic features over the Iberian Peninsula, such as channels like the Ebro Valley or the Strait of Gibraltar, they acquire a certain range of directions and considerable speed due to mass conservation. However, reanalysis products are not able to analyze them because their spatial resolution, larger than 10 km, is usually not high enough to properly describe the orographic characteristics that lead to these regional winds. Here, we explore the application of the COSMO-REA6 very high resolution reanalysis system to study three regional winds in the Iberian Peninsula: Cierzo in the Ebro Valley and Levante and Poniente in the Strait of Gibraltar, for the 2000-2018 period. COSMO-REA6 has a spatial resolution of 6 km (0.055º), much larger than the other current state-of-the-art reanalysis, and so it could better capture regional winds due to its better orographic representation. Cierzo, Levante and Poniente are very relevant due to their intensity and frequency over the regions. Defined with a 5 m/s threshold for each hour and their specific direction range, around 95, 85 and 82 wind days per year are obtained, respectively. Comparison against the small amount of observational data shows that there is reasonable conformity between datasets in terms of statistics and annual cycles. Reanalysis allows us to study regional wind spatial features such as extension statistics (frequency, covered area) of Cierzo along the Ebro Valley or Levante/Poniente over the Strait of Gibraltar. Atmospheric patterns associated with these regional winds indicate great differences between winter and summer patterns. This study aims to increase the current small number of studies focused on regional winds over Europe, with clear interests on wind climatology, meteorological characterization of atmospheric flows and other applications such as renewable energy production.
Unraveling the complexity of the Pollino (Italy) seismic gap fault system.
Authors: Napolitano Ferdinando , Amoroso Ortensia , La Rocca Mario , De Siena Luca , Galluzzo Danilo , Convertito Vincenzo , De Matteis Raffaella , Terakawa Toshiko , Capuano Paolo
Published: March 2022

The Mt. Pollino area has been affected by a 4-year long seismic sequence, occurred between 2010 and 2014 and characterized by low-to-moderate seismicity and two moderate events (ML 4.3 and ML 5.0). The sequence developed as a combination of swarm-like and aftershocks. The two main earthquakes occurred late in the sequence, with a slow-slip event starting 3-4 months before the largest earthquake and lasting for a year. Despite the lack of historical and instrumental recordings of strong earthquakes (M>6), paleo-seismological investigations confirm the occurrence in the last 10,000 years of at least two M 6.5-7 earthquakes on the Pollino and Castrovillari faults, located in the SE sector of the Mt. Pollino area. Thus, the area has been marked as the widest high seismic hazard gap in Italy.

In this study we present the most recent advancements in the comprehension of the main peculiarities of the last seismic sequence and of its space and time evolution.   

New local 3D P- and S-wave tomographic images offered a detailed picture of the main lithological units involved in the sequence and more reliable earthquake hypocenter locations. The inferred velocity contrasts have been compared with 2D scattering and absorption maps computed for the area, along with total direct wave attenuation. Clusters of events of similar waveforms (cross-correlation higher than 0.8) have been selected and located applying the master-slave relative location technique. New fault mechanisms have been computed. These mechanisms allowed modeling the local stress field and performing a Focal Mechanism Tomography. Its result was an evaluation of the excess of pore fluid pressure in the volume interested by the sequence. A 1D diffusivity analysis suggests a pore fluid pressure diffusion which, in addition to the Coulomb static stress transfer, can explain the delayed triggering of the two larger events.

This work has been supported by the CORE (“sCience and human factor for Resilient sociEty”) project, funded from the European Union’s Horizon 2020 - research and innovation program under grant agreement No 101021746 and by PRIN-MATISSE (20177EPPN2) project funded by Italian Ministry of Education and Research.
Conservation tillage practices facilitate soil organic carbon sequestration and aggregate stability via fungal abundance and necromass
Authors: Sae-Tun Orracha , Bodner Gernot , Rosinger Christoph , Weninger Thomas , Zechmeister-Boltenstern Sophie , Mentler Axel , Keiblinger Katharina
Published: March 2022

Conservation tillage has been widely applied to improve soil health, sustain crop production, and promote carbon (C) sequestration in soil. Positive effects often depend on the degree of tillage intensity and time of adoption. This study was thus aimed to determine temporal changes of selected soil health indicators under different tillage intensities in a long-term tillage trial.

Accordingly, bulk and rhizosphere soil samples were taken after 8 and 13 years of adoption from topsoil under four different tillage systems ranging from conventional (high intensity), reduced, minimum, to no-tillage (low intensity).  Aggregate stability and soil fungal indicators (ergosterol and glomalin-related soil protein) were analysed. Soil organic carbon stocks were assessed at 10 and 13 years of adoption. To determine long-term effect of tillage on soil microbial necromass accumulation, amino sugars were measured after 13 years of adoption.

Aggregate stability and soil fungal indicators increased with lower tillage intensity for both sampling time points. Conservation tillage practices promoted the accumulation of soil organic carbon and microbial necromass. Interestingly, among conservation tillage practices, the soil fungal indicators showed highest values for reduced and minimum tillage compared to no-tillage at 13 years of adoption. This suggests that fungal growth could potentially benefit from slight soil disturbance in the long-term. Therefore, reduction of tillage intensity evidently improved soil health by promoting soil carbon sequestration and aggregate stability via fungal growth as well as soil microbial necromass accumulation.

Conventional tillage is most detrimental to soil health indicators, while reduced tillage seem to promote soil biological processes via gentle mixing of soil substrate. Instead, no-tillage is most beneficial to aggregate stability but not for fungal indicators.  
Long-Term Stability of AOD1B RL07
Authors: Shihora Linus , Dobslaw Henryk , Balidakis Kyriakos , Dill Robert
Published: March 2022

The Atmosphere and Ocean non-tidal De-aliasing Level-1B (AOD1B) product is widely used in satellite gravimetry to correct for transient effects of atmosphere-ocean mass variability that would otherwise alias into monthly-mean global gravity fields. The most recent release is based on the global ERA5 reanalysis and ECMWF operational data together with simulations from the general ocean circulation model MPIOM consistently forced with fields of the same atmospheric data-set.

To fully utilize the potential of geodetic data for climate applications, addressing long-term stability in background (or observation-reduction) models is critically important. In this contribution we assess the three hourly tendencies, trends and long-term variations of surface pressure as well as ocean bottom pressure in the new release 07 of AOD1B. Special focus is placed on the transition from ERA5 to ECMWF operational atmospheric data and the influence of model changes in the ECMWF data.
Modeling the response of plant gas exchanges to different light and PAR curves spectra
Authors: Camporese Matteo , Abou Najm Majdi
Published: March 2022

Understanding how plants react to different light treatments is of increasing importance to assess the potential of modern agricultural technologies such as agrivoltaics and hydroponics, which are considered as promising methods to optimize crop productivity and water use without the need to increase land consumption. Here, we extend a well-established model of plant photosynthesis and transpiration to explicitly take into account the spectra of incident light and photosynthetically action radiation (PAR) curves (i.e., absorptance and quantum yield). The proposed model reasonably reproduces the response of various C3 plant types treated with different light spectra in controlled laboratory conditions. A sensitivity analysis to the most important abiotic forcing variables (irradiance, air temperature, humidity and CO2 concentration) suggests that the blue part of the light spectrum is the less efficient in terms of carbon assimilation and water use and could be effectively filtered out to produce solar energy. However, the plant response to different light treatments seems to be species-specific; therefore, accurate and updated PAR curves are needed to assess which crops are more suited to be grown in controlled agricultural systems.
Modeling groundwater flow and solute transport in the active layer of hillslope system in permafrost environments
Authors: Hamm Alexandra , Frampton Andrew
Published: March 2022

Subsurface hydrology in regions dominated by permafrost is expected to change as a response to global climate change. Groundwater transports energy as well as dissolved solutes such as contaminants and carbon. To investigate the changes in advected energy as well as potential implications for solute transport, we created a permafrost hillslope modeling study that simulates current day active layer hydrology as well as future conditions based on climate projections.

Simulations are conducted with a state-of-the-art physically based numerical model (ATS) and combine a generic modeling approach with site-specific boundary conditions representative of the Adventdalen valley in Svalbard. We find that in the current climate, the subsurface hydrothermal state of the active layer along the hillslope transect is affected by lateral groundwater flow through differences in moisture distribution up- and downhill. Although lateral heat advection along the transect was found to be negligible, we show that the moisture distribution by gravitationally-driven seepage flow along the hillslope leads to unexpected temperature differences between the uphill and downhill parts of the transect. A non-negligible warming effect is observed uphill, resulting in deeper active layer depths than downhill.

Additionally, preliminary results based on transport modeling indicate that solute migration is mostly longitudinal and slow due to low liquid saturation of the active layer in summer. Under warmer conditions (increased air temperatures), lateral heat advection is expected to increase with more available energy, but solute migration may be partially counteracted by a greater volume of unfrozen soil in summer caused by less saturated conditions closer to the surface.

Furthermore, we discuss the potential implications this has for subsurface transport of solutes and dissolved constituents, and highlight challenges for numerical modeling of these systems.
Enabling carbon farming: presentation of a robust, affordable and scalable method of carbon stock estimates
Authors: Verweij Sven , van der Voort Tessa , van Doorn Maarten , Fujita Yuki , Ros Gerard
Published: March 2022

The main hurdle in instrumentalizing agricultural soils to sequester atmospheric carbon is a development of methods to measure soil carbon stocks on farm level which are robust, scalable and globally available. We present a method for soil carbon stock assessment using satellite data, stratified sampling design, direct soil measurements via mobile soil sensors and machine learning, which fulfills these criteria. The method has been tested and applied for multiple farms in Europe and the United States on agricultural fields with variable crop rotations, soil types and management history. Results show that the estimates are precise, repeatable and that the approach is rapidly scalable and is able to detect variation in soil carbon stock up to a 10 meter resolution. Carbon stocks in the top 30 cm range between 17-55 ton C/hectare. Error propagation analysis showed that the error associated with the soil sensor on the level of farm C stocks is less than 5%. This precision can be achieved with as few as 0.5 field samples per hectare for farms varying from 60 to 250 hectares, ensuring affordability and scalability of the method. The method is globally applicable because it uses covariates which are also globally available. These findings can enable the structural and widespread implementation of carbon farming with a standardized method. In future, as the calibration dataset increases, even less field data will be needed to obtain robust C stock estimates.
Power density dissipated by field-aligned currents in the topside ionosphere
Authors: Giannattasio Fabio , Consolini Giuseppe , Coco Igino , Pezzopane Michael , Pignalberi Alessio
Published: March 2022

The response of the magnetosphere-ionosphere (MI) system to the forcing by plasma of solar origin gives rise to several phenomena relevant to Space Weather. In particular, part of the energy injected into the ionosphere by means of field-aligned currents (FACs) connecting the magnetosphere with the high-latitude ionosphere is converted into mechanical energy and dissipated via Joule heating. Under reasonable assumptions, in the direction parallel to the geomagnetic field the only relevant contribution to dissipation is from the Ohmic term. Dissipated power density may significantly affect the physical parameters characterizing the upper ionosphere, such as electron temperature and density, and alter its chemical composition. This can result, for example, in the increased atmospheric drag and affect the satellite orbits. For this reason, understanding the dissipation of FACs in the topside ionosphere is important to shed light on the physical processes involved in MI coupling. Power density dissipated by FACs in crossing the topside ionosphere can be estimated by using Swarm data. Here, for the first time, we show statistical maps of power density features dissipated by FACs by using six-year time series of electron density and temperature data acquired by the Langmuir Probes onboard the Swarm A satellite (flying at an altitude of about 460 km) at 1 s cadence, together with the field-aligned current density product provided by the ESA’s Swarm Team at the same cadence. Maps of the same quantity under different levels of geomagnetic activity are also shown and discussed in light of the previous literature.

This work is partially supported by the Italian National Program for Antarctic Research under contract N. PNRA18 00289-SPIRiT and by the Italian MIUR-PRIN grant 2017APKP7T on "Circumterrestrial Environment: Impact of Sun-Earth Interaction".
Timing and Tempo of Deccan volcanism relative to the KPg extinction revealed by Mercury and Tellurium anomalies
Authors: Adatte Thierry , Regelous Marcel , Font Eric , Spangenberg Jorge E. , Keller Gerta , Karabeyoglu Uygar , Mateo Paula , Punekar Jhanavi , Khadri Syed
Published: March 2022

Mercury (Hg) and more recently tellurium (Te) are indicator of large-scale volcanism in marine sediments and provide new insights into relative timing between biological and environmental changes, mass extinctions and delayed recovery. Several studies evaluated the relationship between Hg anomalies in sediments and LIP activity across mass extinction horizons. The bulk (80%) of Deccan Trap eruptions occurred over a relatively short time interval in magnetic polarity C29r. U-Pb zircon geochronology reveals the onset of this main eruption phase 350 ky before the Cretaceous-Tertiary (KT) mass extinction. Maximum eruption rates occurred before and after the K-Pg extinction, with one such pulse initiating tens of thousands of years prior to both the bolide impact and extinction, suggesting a cause-and-effect relationship.

We present a comprehensive high-resolution analysis of Deccan Traps Hg loading, climate change and end-Cretaceous (KPB) mass extinction from a transect, which includes 30 sections deposited in both shallow and deep environments. In all sections, results show that Hg concentrations are more than 2 orders of magnitude greater during the last 100ky of the Maastrichtian up to the early Danian P1a zone (first 380 Ky of the Paleocene). Hg anomalies generally show no correlation with clay or total organic carbon contents, suggesting that the mercury enrichments resulted from higher input of atmospheric Hg species into the marine realm, rather than organic matter scavenging and/or increased run-off. Significant and coeval Hg enrichments are observed in multiples basins characterized by proximal and distal, as well as shallow and deep-water settings, supporting a direct direct fallout from volcanic aerosols. Hg isotope data from Bidart confirm a direct Hg fallout from volcanic aerosols. Te/Th ratios measured in both the Goniuk (Turkey) and Elles (Tunisia) sections show the same trend as Hg/TOC and are consistent with a volcanic origin, albeit a minor extraterrestrial contribution of Hg to the boundary cannot be excluded. Te and Hg are however not correlated with iridium contents in the KPg interval and are consequently not related with impact and maximum eruption rates occurred before and after the K-Pg extinction, with one such pulse initiating tens of thousands of years prior to both the bolide impact and extinction
Global monitoring of soil animal communities using a common methodology
Authors: Potapov Anton ,   Soil BON Foodweb Team
Published: March 2022

Soils host approximately 50% of the biomass and a major part of the diversity of animals on land. However, large-scale data that link soil animal diversity with ecosystem functions is limited to few regional studies, hampering our understanding of soil animal contribution to global biogeochemistry. Besides, global abiotic and biotic drivers and assembly processes in soil animal communities and food webs have not been comprehensively assessed. Here we introduce Soil BON Foodweb Team (SBF Team), a novel international voluntary initiative that addresses these gaps by a standardized global assessment of soil animal communities across micro-, meso-, and macrofauna. By sampling Soil BON sites (https://www.globalsoilbiodiversity.org/soilbon), this initiative is the first to link soil animal communities across the size spectrum to a range of soil functions worldwide. At present the initiative includes soil ecologists from 15+ countries covering all continents. We intend to expand the network and conduct the first sampling campaign in 2022 covering a minimum of 200 sampling sites globally. We are welcome for researchers especially from underrepresented countries. Jointly, we will be able to produce unprecedented data to address exciting and challenging questions and establish a global collaboration network for soil animal diversity monitoring and future joint work.
New insights of airwave in controlled-source electromagnetic offshore data
Authors: Wang Shunguo , Constable Steven , Orange Arnold , Johansen Ståle Emil
Published: March 2022

The marine controlled-source electromagnetic (CSEM) method has been used for offshore natural resource exploration for a few decades, and it has the potential to be used for offshore CO2 storage monitoring. Airwaves, previously treated as distortions, often dominate marine CSEM data when the offshore seawater is shallower than a couple of kilometers. Therefore, different methods have been proposed to distinguish and then correct the airwaves in marine CSEM data. In this study, we analyzed the airwave features by different model parameter perturbations with two-dimensional (2D) modeling. After a thorough study of differentiated EM fields and Poynting vectors for each single model component, we summarize the airwave propagation features and sensitivities regarding different modeling parameters. Particularly, the scenario with and without an oil reservoir or CO2 storage is carefully studied. It turns out that the airwave can provide useful information at certain transmitter and receiver offsets. Nevertheless, we propose to model the airwave as what it is in the marine CSEM data rather than correct it before feeding the offshore CSEM data to inversion. This idea is demonstrated with a field example from offshore of Svalbard, Norway.
Tropospheric ozone columns from TROPOMI/S5P, related nadir sensors and GEMS
Authors: Heue Klaus-Peter , Loyola Diego , Coldewey-Egbers Melanie , Lerot Christophe , van Roozendael Michel , Chabrillat Simon , Errera Quentin , Kim Jae
Published: March 2022

TROPOspheric Monitoring Instrument (TROPOMI) on board the Sentinel 5 P instrument was launched into space in October 2017. Meanwhile the analysed data from several research institutes offer a variety of trace gases columns, including different tropospheric ozone data set. One based on the Convective Cloud Differential algorithm is an official TROPOMI data product. The algorithm in an improvement of the algorithm developed for the ESA ozone CCI project. It uses the offline (OFFL) ozone total columns and the cloud data sets. The data agree well with data from other satellite missions, i.e. GOME-2 or OMI. Therefore they will extent the time series started in 1995 with GOME / ERS2 developed during the CCI project. However despite the long time series of the CCD data set, the CCD algorithm can only be applied within the tropics (20°S -20°N).

A completely different approach uses data assimilation to constrain the stratospheric ozone and subtract the stratosphere from the total column. This offers the possibility to study tropospheric ozone on a global scale. We developed an algorithm for the scientific product that will be presented as well. Ozone observation from the microwave limb sounder (MLS) on the AURA satellite constrain the ozone distribution in the BASCOE (Belgian Assimilation System for Chemical ObsErvations) assimilation model. The BASCOE ozone concentrations are integrated above the tropopause to calculate the stratospheric column. Interpolated stratospheric columns are subtracted from the TROPOMI total ozone columns. The tropospheric ozone data agree reasonable well with comparable data from NASA using OMPS total columns, and within the tropics also with the CCD data. The algorithm was extend to be used also for other total ozone column observations like from GOME-2, OMI. But also geostationary observers like GEMS can in principal be used and might give intersting insight in the daily cycle of tropospheric ozone.
Scatterometer soil moisture data for the conceptual rainfall-runoff model
Authors: Kubáň Martin , Brziak Adam , Rattayová Viera
Published: March 2022

The different approaches for the improvement of the calibration processes of the conceptual hydrological models are annually introduced. In our paper, we focus on the improvement of runoff and soil moisture simulation, by the assimilation of the scatterometer soil moisture to the calibration process of the HBV type rainfall-runoff model. The model was single-calibrated for runoff and multi-calibrated for the combination of the runoff and the combination of the soil moisture data for the root and surface soil zone. We validated the model in the two-period and compare the simulation results between the single and multi-objective approaches. The improvement of the soil moisture simulation was detected in almost 80% of the catchments, in the case of the runoff simulation we detect the improvement in almost 30% of the catchments, mainly in the catchments with a lower mean elevation, narrower terrain, and higher agricultural land percentage.
3D geological modelling of fluvio-glacial aquifers to improve water work operations
Authors: Ehrendorfer Johannes , Marazuela Miguel Anchel , Erlmeier Klaus , Formentin Giovanni , Seidl Georg , Hofmann Thilo
Published: March 2022

Fluvio-glacial aquifers in subalpine quaternary basins are global sources of drinking water.
Water works need to consider the geological framework of such aquifers to optimize 
groundwater management. This can be achieved by developing 3D geological models, which 
act as powerful tools for aquifer visualization and estimation of hydraulic properties. In recent 
years 3D geological modeling has emerged as an asset to sustainable groundwater management. 
However, the implementation of such models is no trivial task and requires expert geological 
knowledge. In this study a 3D geological model is developed for a subalpine quaternary basin,
that provides drinking water to a major city. The relationship between aquifer geometry and 
heterogeneity, preferential flow paths, and observed hydraulic and hydrochemical trends is
investigated. A database consisting of around 300 bore logs as well as geophysical, hydraulic
and hydrochemical data provides the foundation for the 3D geological model. The software 
package Leapfrog Works is employed to create the model. The resulting model depicts the 
complexity of the fluvio-glacial stratigraphy and the hydrogeological units of the study area 
and demonstrates the retarding effect that glacial terraces can have on flood wave propagation 
in aquifers. It allows the assessment of total groundwater volume and areas of low hydraulic 
conductivity. Our understanding of aquifer interconnectivity and constraints imposed on 
groundwater flow in fluvio-glacial quaternary sediment basins is improved. As such, 
recommendations for future groundwater explorations in subalpine basins are provided.
The effect of subsurface freezing-thawing in the SW Svalbard on the newly deglaciated areas
Authors: Majdański Mariusz , Dobiński Wojciech , Marciniak Artur , Osuch Marzena , Wawrzyniak Tomasz , Owoc Bartosz , Glazer Michał
Published: March 2022

The rapid climatic changes and their impact in the regions where unique environmental balance is not polluted by human existence are strongly visible. One of those places, exposed to Arctic amplification, is the newly deglaciated areas of Southern Spitsbergen. One of the most important scientific aspects is understanding their response to climate and environmental changes. To do that, an extensive geophysical approach is required integrating results from multiple imaging techniques. To derive spatial information from complex geomorphological terrain, joint interpretation of three non-intrusive geophysical methods were applied: Electrical Resistivity Tomography, Ground Penetrating Radar, and time-lapse Seismic Tomography. These were used to identify subsurface structures in the forefield of the retreating Hansbreen glacier in SW Spitsbergen, Svalbard. As a result, the authors distinguish three main zones, with different responses to the freezing-thawing effect: outwash plain, terminal moraine at the last glacial maximum, and glacial forefield proximal to the glacier front. The obtained data allowed for differentiation between geological and periglacial structures, and seasonally changing effects. The estimation of the impact of the freezing-thawing effect based on the VP velocity change reveals, that changes are deeper than previously believed reaching down to 30 metres of flat terrain and even deeper to 40 metres at the slope area with the strong subsurface flow. The study provides a unique snapshot of the current situation on the forefield of retreating Hansbreen concerning the current climate state.

This research was funded by National Science Centre, Poland (NCN) Grant UMO-2016/21/B/ST10/02509 and, Poland (NCN) Grant 2020/37/N/ST10/01486.
Two-dimensional analysis of the irrigation needs in Danubian Lowland in Slovakia
Authors: Cisty Milan , Povazanova Barbora
Published: March 2022

A water shortage implies various adverse effects on agriculture and various other risks associated with the scale and duration of the rainfall deficit. Water scarcity and droughts directly impact the inhabitants and different economic sectors of a region that directly depend on water, such as agriculture, industry, energy, tourism, or transport.

Quantifying the expected probability characteristics of droughts assists in the planning and managing of water resources. The present work's authors described analyses from the perspective of irrigation system management and have performed a joint analysis of the severity and duration of the most important potential annual irrigation periods by a bivariate copula methodology. Basic climatic variables (temperature and precipitation) were used to determine the two derived variables that characterize dry and hot periods requiring irrigation in this work. Such a period is defined by its duration and the rainfall deficit with respect to the normal period (1960—1990). The hot and dry periods that lasted the longest for each year were identified. The duration was derived from the number of consecutive days with temperatures above 25°C. The hot period identified was extended by precipitation-free days before and after it. This variable is herein referred to as the maximum annual length of the potential irrigation period. The maximum yearly length of the potential irrigation periods and the corresponding rainfall deficit were inputs for a two-dimensional probability analysis by a copula methodology. The study was carried out on an agricultural area in Slovakia with a warm and relatively dry climate - the area of the Danubian Lowland around the municipality of Hurbanovo.

The results of this work indicate that in the context of the case study, the need for irrigation occurs very often. For example, every second year, a period can be expected in which temperatures above 25 °C occur. A dry period usually lasts one month with a moisture deficit of about 30 mm. Precipitation of 80 mm in such a period (which would be needed to maintain this limit) occurs with a probability in the upper quartile, i.e., it is scarce. Even more significant periods of drought can be expected, for example, with a five or 10-year return period. These phenomena result in considerable damage to agriculture yields, which, as is often declared in the domestic water management community, are more significant than the investment needed for the reliable maintenance or reconstruction of irrigation systems.
How Significant are the Longwave Radiative Effects of the Cloud-Aerosol Transition Zone?
Authors: Jahani Babak , Andersen Hendrik , Calbó Josep , González Josep-Abel , Cermak Jan
Published: March 2022

In this communication, we have found that the broadband longwave radiative effect of the cloud-aerosol transition zone conditions is of the order of 8.0 ±3.7 W m−2 by combining satellite measurements with radiative transfer modeling. It is often required to differentiate clouds and aerosols from each other in atmospheric studies, but the decision on where the boundaries of the clouds should be put is a point of debate. As a result, what detected as cloud by one method/instrument may be labeled differently by another. This is because 1) clouds and aerosols often co-exist and interact with each other, and 2) change in the state of sky from cloudy to cloudless (or vice versa) comprises an additional condition called “transition zone” (or “twilight zone”) at which the characteristics of the particle suspension lay between those corresponding to pure clouds and atmospheric aerosols [Koren et al. (2007) GRL, 34(8): L08805. 10.1029/2007GL029253]. Nevertheless, a vast area that potentially may represent the transition zone is usually neglected in the observations or assumed as an area that contains either aerosols or optically thin clouds. In this communication, we provide quantitative information about the broadband longwave radiative effects of the transition zone conditions at the top of the atmosphere based on the radiative observations made by the CERES and MODIS instruments onboard Aqua spacecraft and radiative transfer simulations. Specifically, we used the MODIS measurements to look for CERES footprints with homogeneous transition zone and clear-sky conditions over the Southeast Atlantic Ocean for August 2010. Then, CERES observations under homogeneous transition and clear-sky conditions were compared with the corresponding clear-sky radiances, which were simulated using the SBDART radiative transfer model, fed with ERA5 reanalysis atmospheric profiles. For the studied period and domain, transition zone broadband longwave radiative effect was on average equal to 8.0 ±3.7 W m−2 (heating effect; median: 5.4 W m−2), although cases with radiative effects as large as 50 W m−2 were observed. Furthermore, low-level transition zone conditions defined as those with suspension top height below 2 km (determined based on the difference between the layer top and surface temperature) on average produced a radiative effect of about 4.6 W m−2. The lowest layers (temperature difference less than 4 K) produced on average a radiative effect of 0.8 W m−2.
Ocean observations indicate a key role for ocean dynamics in Atlantic Multidecadal Variability
Authors: Moat Ben , Sinha Bablu , Fraser Neil , Hermanson Leon , Josey Simon , King Brian , Macintosh Claire , Berry David , Williams Simon , Oltmanns Marilena
Published: March 2022

Multidecadal changes in North Atlantic Ocean heat storage directly affect the climate of the surrounding continents, and it is important to understand how and why the changes are taking place. Here we synthesize a wide range of observational datasets to construct an upper ocean heat budget for the period 1950 to 2020. Lead-lag correlation analysis of time series of ocean heat content, horizontal heat transport, sea surface temperature and air sea fluxes are used to infer the drivers North Atlantic heat content changes. We find systematic and interconnected migration of heat content anomalies around both subtropical and subpolar gyres and between the near surface and deep ocean on multidecadal timescales. We find a significant driving/active role for ocean circulation in these migrations throughout the North Atlantic. In contrast, air sea interaction mainly plays an active/driving role in the western subpolar Atlantic. Our use of multiple independent observational estimates of the variables allows us to provide robust error/uncertainty estimates for the evolution of the North Atlantic heat budget terms.