bluuebunny/crossref_metadata_2025 huggingface dataset:
The impact of COVID-19 confinement measures on the canopy urban heat island intensity of Ghent (Belgium)
Authors: Hamdi Rafiq , Tronquo Emma , Bogaerts Eva , Hoang Kim-Marie , Loudeche Corentin , Claeys Ellen , Caluwaerts Steven , Duchêne François , Van Schaeybroeck Bert , Termonia Piet
Published: March 2022

In the context of the COVID-19 outbreak, a strict lockdown was ordered by Belgian authorities from 18/03/2020 till 04/05/2020. This led to a limitation of industrial production, human activities and transport use where only essential motorized transport were permitted. This research is an attempt to study the impact of these measures on the canopy layer urban heat island intensity in the city of Ghent. We used the high-accuracy observational MOCCA (MOnitoring the City’s Climate and Atmosphere) network. This network is monitoring the urban climate of the city of Ghent since July 2016. The network consists of six weather stations in the Ghent region and provides a database of hourly observation including 2m temperature at six locations (including dense urban, industrial and suburban). Only clear-sky days with an average wind speed lower than 3 m/s were selected for both the confinement period in 2020 and for similar periods in the reference years 2017, 2018 and 2019. For the years 2017, 2018 and 2019 respectively 3, 3 and 7 reference days were retained to compare with 9 selected days of the 2020 confinement period. Results indicate a lower UHI intensity during the day for 2020 compared to the reference years for the dense, industrial and suburban site. A statistically significant difference was found at 15h, 16h, and 17h for the dense urban site (Provinciehuis). The statistical test did not give significant difference for the suburban site (Wondelgem). Human activities in the urban dense areas release a large amount of heat, which can directly heat the air and during the daytime around 16h when the storage heat flux switch from positive to negative values with weak value of the net radiation fluxes, the external source of energy due to the anthropogenic heat can drive the surrounding hot air to mix with local air and further warm near‐surface air temperature (2 m above ground level). However, during the lockdown period this external contribution to the surface energy balance was absent inducing a cooling gradient of the temperature in the dense urban site (Provinciehuis) up to 0.4°C/h around 18h-19h stronger in 2020 compared to the references years. During nighttime the UHI intensity becomes larger mainly driven by the release of energy stored during the day and the UHI intensities are similar for 2020 and the reference years indicating that the lockdown measures will not have had an impact on the UHI intensity during the night.
Olivine texture evolution under simple deformation: Comparing different numerical methods for calculating LPO and anisotropic viscosity
Authors: Wang Yijun , Király Ágnes , Conrad Clinton Phillips , Hansen Lars , Fraters Menno
Published: March 2022

The development of olivine texture, or lattice preferred orientation (LPO), has been implemented in many numerical modelling tools to predict seismic anisotropy, which places constraints on mantle dynamics. However, a few recent studies have linked olivine texture development to its mechanical anisotropy, which in turn can affect deformation rates and also the resulting texture. To study the effect of anisotropic viscosity (AV) and LPO evolution in geodynamics processes, it is important to know the role of AV and LPO and the differences between the numerical methods that calculate them.

The modified director method parameterizes the olivine LPO formation as relative rotation rates along the slip systems that participate in the rotation of olivine grains due to finite deformation. When it is coupled with a micromechanical model for olivine AV, it allows the anisotropic texture to modify the viscosity. We compare the olivine textures predicted by the modified director method both with and without a coupled micromechanical model and textures predicted by the D-Rex LPO evolution model. To do this, we recalculate the texture observed in simple 3D models such as a shear box model and two other well-understood models: a corner flow model and a subduction model. 

In general, we observed that the D-Rex models predict a stronger anisotropic texture compared to the texture predicted by the modified director method both with and without the micromechanical model, in agreement with previous studies. When including the micromechanical model, the anisotropic texture changes the observed strain rates, which allows for a slightly faster texture evolution that is more similar to the D-Rex predictions than it is to those produced by the modified director method alone. We found that even for the simplest settings there is an increase of 10~15% in strain rate during deformation until a strain of 2.5. When shearing the asthenosphere over ~10 Myr, such anisotropy could modify the effective viscosity of the mantle,causing an up to 40% increase in plate velocity for the same applied stress. The anisotropy can also induce deformation in planes other than the initial shear plane, which can change the direction of the primary deformation.

Our ultimate goal is to understand the role of AV and LPO evolution in geodynamic processes by looking at deformation paths predicted by geodynamic models in ASPECTWith this initial test, we will gain a basic understanding of olivine AV behavior and LPO evolution under different deformation settings calculated with different numerical methods, which we will carry onto our next step of implementing anisotropic viscosity of olivine in 3D into ASPECT.
Multiphase observations of a meteoroid in Iceland recorded over 40 km of telecommunications cables and a large-N network
Authors: Vera Rodriguez Ismael , Dahm Torsten , Isken Marius P. , Kraft Toni , Lamb Oliver D. , Wu Sin-Mei , Heimann Sebastian , Sanchez-Pastor Pilar , Wollin Christopher , Baird Alan F. , Wüstefeld Andreas , Kristjánsdóttir Sigríður , Jónsdóttir Kristín , Eibl Eva P. S. , Goertz-Allmann Bettina P. , Jousset Philippe , Oye Volker , Obermann Anne
Published: March 2022

On July 2, 2021, around 22:44 CET, a meteoroid was observed crossing the sky near Lake Thingvallavatn east of Reykjavik in Iceland. During this event, a large-N seismic network consisting of 500, 3-component geophones was monitoring local seismicity associated with the Hengill geothermal field southwest of the lake.  In addition to the large-N network, two fiber optic telecommunication cables, covering a total length of more than 40 km, were connected to distributed acoustic sensing (DAS) interrogation units. The systems were deployed under the frame of the DEEPEN collaboration project between the Eidgenössische Technische Hochschule Zürich (ETHZ), the German Research Centre for Geosciences (GFZ), NORSAR, and Iceland Geo-survey (ISOR). Both the large-N and the DAS recordings display multiple trains of infrasound arrivals from the meteoroid that coupled to the surface of the earth at the locations of the sensors. In particular, three strong phases and multiple other weaker arrivals can be identified in the DAS data.

Fitting each of the strong phases assuming point sources (i.e., fragmentations) generates travel time residuals on the order of several seconds, resulting in an unsatisfactory explanation of the observations. On the other hand, inverting the arrival times for three independent hypersonic-trajectories generating Mach cone waves reduces travel time residuals to well under 0.5 s for each arrival. However, whereas the 1st arrival is well constrained by more than 900 travel times from the large-N, DAS and additional seismic stations distributed over the Reykjanes peninsula, the 2nd and 3rd arrivals are mainly constrained by DAS observations near Lake Thingvallavatn. The less well-constrained, latter trajectories show a weak agreement with the trajectory of the first arrival. Currently, neither the multi-Mach-cone model nor the multi-fragmentation model explain all our observations satisfactorily. Thus, traditional models for interpreting meteoroid observations appear unsuitable to explain the combination of phase arrivals in the large-N network and DAS data consistently.
Transport of mafic magma through the crust and  sedimentary basins: Jameson Land, East Greenland
Authors: Eide Christian Haug , Schofield Nick , Howell John , Jerram Dougal
Published: March 2022

Igneous sheet-complexes transport magma through the crust, but most studies have focused on single segments of the magma-transport-system or have low resolution. In the Jameson Land Basin in East Greenland, reflection-seismic data and extensive outcrops give unparalleled constraints on mafic intrusions down to 15 km. This dataset shows how sill-complexes develop and how magma is transported from the mantle through sedimentary basins. The feeder zone of the sill-complex is a narrow zone below basin, where a magmatic underplate body impinges on thinned crust. Magma was transported through the crystalline crust through dykes. Seismic data and published geochemistry indicate magma was supplied from a magmatic underplate, without perceptible storage in crustal magma-chambers and crustal assimilation. As magma entered the sedimentary basin, it formed distributed, bowl-shaped sill-complexes throughout the basin. Large magma volumes in sills (4-20 times larger than the Skaergaard Intrusion), and few dykes highlight the importance of sills in crustal magma-transport. On scales smaller than 0.2 km, host-rock lithology, and particularly mudstone tensile strength-anisotropy, controls sill-architecture in the upper 10km of the basin, whereas sills are bowl-shaped below the brittle-ductile transition zone. On scales of kilometres and towards basin margins, tectonic stresses and lateral lithological changes dominate architecture of sills.
Basal thermal regime investigations at Whymper hanging Glacier (Aosta Valley – Italy)
Authors: Troilo Fabrizio , Paolo Perret , Gottardelli Simone , Mondardini Luca , Giordan Daniele , Dematteis Niccolò , Piard Luc , Gagliardini Olivier , Gilbert Adrien , Vincent Christian
Published: March 2022

The Grandes Jorasses Massif culminates at 4203m at the Punta Walker summit on the border between France and Italy. The south slope of Grandes Jorasses is widely glaciated and overlies the Val Ferret, a populated and highly frequented area presenting different hamlets, the most important being Planpincieux village. Located at an altitude between 4000 and 4100 m, the Whymper Serac is a hanging glacier that undergoes periodic gravity-driven instabilities. On 1st June of 1998, 150.000m3 of ice fell, and the resulting ice avalanche reached 1750m, at a distance of about 400m from houses of the Le Pont village and the main road. The monitoring activity started in 1997: a  series of boreholes had been drilled to assess the basal thermal regime of the serac and subsequently install a monitoring system for early warning signs and risk assessment

In September 2020, three thermistor chains in three different boreholes were installed on Whymper Serac. Temperature profiles were measured at different periods between October and November 2020. In September 2021 another three thermistor chains were installed and their temperature profile measured in October 2021. During the same survey, temperature profiles of the 2020 thermistors could be measured again on 2 out of 3 boreholes, (one being too close to the serac front was not safe to reach) confirming data acquired on the 2020 field campaign. The outcome of basal temperature measurements of 2020 and 2021 give good spatial coverage of the serac allowing comparison with data from the 1997 measurements, despite on the fact that most of the ice mass fell in 1998.

A warming trend in most of the temperature profiles is evident in comparison whith 1997 data; 5 out of 6 points of measure still show temperatures below 0° C. One point of measure shows evidence of temperate ice at the ice/bedrock interface. Whymper Serac measurements provide evidence that the glacier is still frozen to the bedrock, but one part of the serac shows the beginning of a potential transition from cold based regime to temperate based regime. If, on one hand, surface displacements of the ice mass still show low displacements (typical of a cold based glacier), on the other hand, a velocity anomaly was detected on a small portion of the serac corresponding to the temperate based sector. Further research is needed to better understand the evolution of the thermo-mechanical conditions of the Whymper Serac in the current climate change scenarios. Therefore, thermo-mechanical modeling of the Whymper Serac is underway, based on the Elmer/Ice model.
Differences in the regional pattern of projected future changes in extreme precipitation over Europe are driven by the dynamic contribution
Authors: Ritzhaupt Nicole , Maraun Douglas
Published: March 2022

Heavy precipitation is a major natural hazard that can have severe impacts.  In response to global warming, the character of heavy precipitation is expected to change. Projections of the future hydrologic cycle, especially of heavy precipitation, are uncertain. Especially at the regional scale, different data sources, such as different ensembles of global and regional climate models (GCMs and RCMs), provide sometimes conflicting conclusions. Therefore, it is even more important to investigate where differences between ensembles lie and to which processes they can be attributed.

A precipitation scaling (introduced by Paul O’Gorman) is used to disentangle thermodynamic and dynamic contributions in extreme precipitation. In this work, we compare the results of CMIP5 and CMIP6 and focus on climate change signals between the periods 1971-2000 and 2071-2100 over Europe. The thermodynamic component provides homogeneous signals across Europe with a rise in extreme precipitation of about 7 %/K. In contrast, the dynamic component shows no spatial homogeneous results where the dynamic contribution can even modify the thermodynamic signal. The spread between the models within one ensemble is much larger. However, based on initial analyses, the spread in the CMIP6 models appears to have become smaller compared to CMIP5. This means, understanding the dynamic changes is the key to understanding the differences between the ensembles.

As a next step, to analyze the discrepancy between CMIP5 and CMIP6 in terms of atmospheric circulation changes, we look into three atmospheric drivers: tropical and polar amplification of global warming and changes in stratospheric vortex strength.  
Investigation of the glyoxal tropospheric column variability observed from space during wildfire events
Authors: Lerot Christophe , Theys Nicolas , De Smedt Isabelle , Van Roozendael Michel , Stavrakou Trissevgeni , Müller Jean-François
Published: March 2022

Wildfires release in the atmosphere large amounts of aerosols and ozone precursors and have a significant impact on air quality and the climate. Global warming leads to more frequent and intense wildfires such as those that occurred in Australia in January 2020, in Siberia in 2021 or in California in the last few years. The spaceborne TROPOspheric Monitoring Instrument (TROPOMI) launched in October 2017 onboard the Sentinel-5 Precursor platform provides invaluable information on a series of key trace gases (NO2, HONO, CO, HCHO, CHOCHO)and on aerosols. Its daily global coverage and high spatial resolution are ideal to monitor wildfire emissions and to characterize their spatial extent and temporal evolution.

In this work, we present an analysis of the trace gas distributions observed by TROPOMI for various selected intense wildfire events, with a specific focus on glyoxal (CHOCHO). Primarily emitted gases such as NO2 show intense signals near the fire sources with limited spatial extent. On contrary, other species like formaldehyde, carbon monoxide and glyoxal are mostly produced via secondary processes, which contribute to extend significantly their spatial spread. Those TROPOMI spatial patterns are consistent with the current knowledge of the different production mechanisms. However, we report here the identification of a very strong reduction of glyoxal slant columns in presence of very high clouds or aerosols, while other gases do not show such behavior. Uptake on aerosols or cloud droplets is a known destruction mechanism for glyoxal and is the most likely cause for this signal reduction. We hypothesize that, owing to its high solubility in water, glyoxal is transferred into the liquid phase within the convective cells of (pyro)cumulus clouds and that (contrary to formaldehyde) it is not degassed upon freezing and therefore remains in the condensed phase in the upper troposphere. We investigate the conditions in which this process is observed by correlating the glyoxal level with e.g. the fire intensity, the presence of high clouds and their altitude (pyrocumulonimbus), atmospheric conditions (temperature and humidity), the nature of the burning eco-system, etc. 
Exploring the impact of different past- and present-day climatic forcings on Antarctic Ice sheet evolution
Authors: Wirths Christian , Sutter Johannes , Stocker Thomas
Published: March 2022

Simulations of past and future Antarctic ice sheet (AIS) evolution depend, besides the intrinsic model specific uncertainties, on the applied climatic forcing. To model the past, present and future Antarctic Ice Sheet, a large set of different forcings from global and regional climate models, is available. For a more complete understanding of the modeled ice sheet dynamics, it is therefore critical to understand the influence and the resulting model differences and uncertainties associated with climate forcing choices.  

In this study we examine the impact of different climatic forcings onto the equilibrium state of the AIS for past and present-day conditions. We apply past (LGM, LIG, mid-Pliocene warm period) and present-day climatic forcings from regional (RACMO2.3p2, MAR3.10, HIRHAM5 and COSMO-CLM) and global (PMIP4 ensemble) climate models onto the Parallel Ice Sheet Model (PISM v.2.0). Further, we investigate the response of the total ice mass, its distribution and the grounding line dynamics of the modeled equilibrium ice sheet under varying ice sheet sensitivity parameterizations.  

With this analysis, we aim to gain a better understanding of AIS modelling uncertainties due to the applied climatic forcings and parameterizations, which will improve the assessment of modeled past and future ice-sheet evolution.  
Observed changes and coherence in the Gulf Stream system 
Authors: Asbjørnsen Helene , Eldevik Tor , L. Johnson Helen
Published: March 2022

The steady supply of warm Gulf Stream water to subpolar latitudes is crucial for maintaining a mild, maritime climate in north-western Europe. Ongoing anthropogenic climate change has prompted the oceanographic community to ask whether a slowdown of the North Atlantic circulation has occurred as a response to changes in heat and freshwater fluxes. The question has also caught the attention of policy makers and the media. However, climate models, ocean transport measurements, and paleo and proxy reconstructions show large discrepancies regarding the ‘state’ of the North Atlantic circulation over the historical period. Here, we use available measurements of North Atlantic and Nordic Seas circulation strength to discuss and reflect on potential circulation slowdown. The measurements indicate a stable circulation, but the short record makes distinguishing potential long-term trends from interannual and decadal variability difficult. The sensitivity seen in literature to methodology, data type, region, and time period over which trends are evaluated, demonstrates the lack of robust evidence for a circulation slowdown. The findings warrant caution and nuance in terms of interpreting and communicating research on past and future changes in North Atlantic circulation strength.  
A multiplatform data experiment to characterize waves and currents in front of Biarritz main beach
Authors: Solabarrieta Lohitzune , Delpey Matthias , Rubio Anna , Caballero Ainhoa , Liria Pedro , Fernandes-Salvador Josean A. , Carrasco-Álvarez Ruben , Somdecoste Tom , Mader Julien , Horstmann Jochen , Clot Alexandre
Published: March 2022

Quality physical oceanographic data such as currents and waves are needed to understand processes and produce forecasts for multiple scientific, management and industry applications. Some of the applications that require currents and waves data are the estimation of climate change impacts, marine species distribution changes, litter accumulation in beaches and vessels fuel consumption. The X-band radar can provide such currents and waves data in near real time.

An X-band radar (transmission frequency: 9410 ± 30 MHz) was installed in Biarritz in March 2021 and it is expected to acquire data until the end of February 2022, as part of the SusTunTech project (https://www.sustuntech.eu/the-project/). Since it´s installation, the x-band radar has been measuring data non-stop, except during few days (due to power failures). The radar is monitoring oceanographic processes at coastal scales in this shallow water coastal area up to 3.2 km offshore. The main parameter extracted from the radar data are spectral wave parameters such as significant wave height, peak wave period and direction as well as surface current fields. During a short calibration phase, the marine radar has to be calibrated for significant wave heights utilizing in situ measurements. For accurate surface current measurements from the X-band radar, the tidal water depth variation of up to 4 m in the study area is being taken into account.  Four ADCPs and two pressure sensors were installed in the area covered by the x-band radar from March to May 2021 as part of MARLIT project (https://www.suez.com/en/news/marlit-project-prevention-storm-related-risks-protection-coast-against-climate-change) to strengthen the x-band radar data information.

The presented multiplatform experiment (in-situ data from MARLIT project and X-band from SusTunTech project) is allowing to compare the measurements of the same variable by different instruments and find complementarities of these instruments to characterize the wave regime and the surface currents of the study area. In addition, these measurements will be utilized to validate and better understand the remarkable intensification of significant wave heights suggested by local wave models at specific locations within the area covered by the X-band area (Varing et al. 2020). Finally, the better knowledge acquired about the longshore distribution of wave and current energy will help to assess local early warning systems to prevent storm-related risks along the highly urbanized coastline of Biarritz. Nowadays, such systems are increasingly being used by scientists, policy and industry in their activities. Therefore, the importance of producing quality data to feed modelling and its applications.
Development of an energy analyser for the characterization of the neutral and ionized upper atmosphere.
Authors: Steichen Valentin , Leblanc François , Berthelier Jean-Jacques , Gilbert Pierre
Published: March 2022

Measurements in the thermosphere are essential for understanding the solar forcing induced by the solar UV/EUV radiation, the particle precipitation and all sources of heating of this region of our atmosphere controlled by our Sun. Despite its significance, the Thermosphere Ionosphere (TI) stands as the least measured and understood of all atmospheric regions. Altitudes between ~100 to 200 km, where the magnetospheric current systems close and where Joule heating maximizes, are too high for balloon experiments and too low for existing LEO satellites. Moreover, characterizing this heating implies to be able to perform accurate measurements of the velocity, composition and density of the main species in this region.

Here we propose an instrument called INEA (Ions and Neutral Energy Analyser) that will be able to measure the density, temperature and drift velocity along the axis of sight of the instrument of neutral and ionized atmospheric particles with an accuracy compatible with DAEDALUS project (Sarris et al., Geosci. Instrum. Method. Data Syst., 2020). In order to analyse the energetic structure of particles within the TI, INEA’s performance must achieve resolutions lower than 20 K and 20 m/s over a wide range of densities.

In this presentation, I will present the concept of the instrument, the expected performances based on a complete numerical model of the instrument and the results of first experiments on parts of the instrument.  With such accuracy, such an instrument could be used for other issues related to other planetary objects such as Mars where the direct measurement of atmospheric exhaust remains a challenge due to the inability of current mass spectrometers to measure the energy of neutral particles with enough accuracy.
French feedback from urban soil geochemical data archive to data sharing: state of mind and intent 
Authors: Le Guern Cecile , Brunet Jean-François , Négrel Philippe , Lemal Sandrine , Taffoureau Etienne , Grellet Sylvain , Beaufils Mickael , Lattelais Clément , Le Bas Christine , Roussel Hélène
Published: March 2022

Urban territories collect many types of geochemical and physico-chemical data relative to, e.g., soil quality or soil functions. Such data may serve for various purposes like verifying the compatibility with current or future uses, defining (pedo)geochemical backgrounds, establishing levels of exposure to soil pollutants, identifying management options for polluted sites or for excavated soils, verifying the evolution of infiltration ponds, assessing carbon storage, etc. They may also serve to prioritize soil functions and associated ecosystem services such as, e.g., soil fertility, surface and groundwater storage or supply, purification of infiltrated rainwater, etc. Gathering such data in national databases and making them available to stakeholders raises many issues that are technical, legal and social.  Should all of the data be made available or only selected portions? How can access and reuse of the data be ensured in a legal fashion? Are statistical and geostatistical methods able to deal with data from heterogeneous origins, allowing their reuse for other purposes than the initial one? In this context, it is necessary to take into account scientific as well as practical considerations and to collect the societal needs of end-users like urban planners.

 

To illustrate the complexity of these issues and ways to address them, we propose to share the French experience:

on gathering urban soil geochemical data in the French national database BDSolU. We will present how this database was created, the choices made in relation with the national context, the difficulties encountered, and the questions that are still open.

on a new interrogation system linking agricultural and urban soil databases (DoneSol and BDSolU), which have different requirements, and the corresponding standards. Such linkage based on interoperability is important in the context of changes of soil use, with for example agricultural soils becoming urbanised soils, or soils from brownfields intended for gardening. It is also necessary to ensure a territorial continuity for users.

The objective is to define a robust and standardised methodology for database conceptualisation, sharing and final use by stakeholders including scientists
Wave decomposition of energy transport using deep-learning
Authors: Heiskanen Tuomas Ilkka Henrikki , Graversen Rune
Published: March 2022

Energy transport in the atmosphere is accomplished by systems of several length scales, from cyclones to Rossby waves. From recently developed Fourier and wavelet based methods it has been found that the planetary component of the latent heat transport affects the Arctic surface temperatures more than its dry-static counterpart and the synoptic scale component of the latent heat transport.  

However, both the Fourier and wavelet based methods require enormous amounts of data and are time consuming to process. The Fourier and wavelet decompositions are computed  from 6 hourly data, throughout the whole vertical column of the atmosphere. The data required are usually only available from reanalysis archives, or possibly from climate model experiments where a goal is to examine the decomposed energy transport. However, the vast CMIP5 and CMIP6 archives are out of reach for the exact computations of the Fourier and wavelet decompositions. Even if all the data were available in the CMIP archives, it would be a computationally, and storage-wise, intensive task to compute the Fourier and wavelet decompositions for a large selection of the CMIP experiments.

Here we suggest a deep-learning approach to approximate the decomposed energy transport from significantly less data than the original methods. The idea is to train a convolutional neural network (CNN) on ERA5 data, where we have already computed the Fourier decomposition of the energy transport. The CNN is trained on data at 850hPa in the atmosphere on a daily temporal resolution. The required data are only a small fraction of the data required to compute the exact Fourier decompositon of the energy transport. Once the CNN is trained, the model is tested on data from the EC-Earth climate model. For EC-Earth we have an ensemble of model runs where the energy transport is decomposed using the Fourier method, hence the CNN may be evaluated on the EC-Earth dataset.

The CNN based energy transport decomposition matches well with the classically computed energy transport from EC-Earth.The CNN captures the mean meridional transport well, and the projected changes from the 1950s to the 2090s in EC-Earth. Additionally the CNN model captures the day to day variability well, as regressions of temperature on the transport from the CNNcomputations and the classical Fourier decomposition are similar. Further we may investigate how the decomposed energy transport changes in a range of CMIP models and experiments
A method for characterizing the earthquake-inducing capacity of hydraulic fracturing
Authors: Hu Jun , Yang Hongfeng , Zhang Haijiang , Tan Yuyang
Published: March 2022

The seismicity rate in the Southern Sichuan Basin, China (SSBC), has increased by orders of magnitude within the past a few years accompanying the rapidly growing hydraulic fracturing (HF) operations. However, there is currently no appropriate method to directly determine whether a HF platform has induced seismicity and to quantitatively describe its potential of inducing earthquakes. In this study, by taking advantage of a more complete seismic catalog constructed from temporary short-period seismic stations and broadband stations for two adjacent well pads in the SSBC, we investigate a new statistical metrics for detailed studies of earthquake clusters on the "pre- and post-fracture" time scales to characterize their earthquake-inducing capacity. After declustering the earthquake catalog, a small-scale “Spatiotemporal Association Filter (SAF)” is designed to obtain seismic data closely associated with six independent fracturing well groups, and an “Unit Seismic Energy Release (USER)” index is established to evaluate the potential to induce earthquakes. Comparing the differences in the index before and after fracturing, as well as the nonparametric statistical test of each well group’s “Interevent time (IET)” and historical IET, four of the well groups are considered “induced-seismic”, and the other two are “anti-seismic”. The HF well with the largest USER value has the largest inducing capacity. The paired result of the nonparametric test shows that the p values are less than 0.001, indicating significant statistical differences between the IET series before and after the HF process around the four induced-seismic wells. To sum up, our method can conveniently distinguish the earthquake-inducing capacity of different HF wells, and thus offer practical advice for HF operation in the SSBC.
The impact of climate change on groundwater temperature of the Piedmont Po plain (NW Italy)
Authors: Egidio Elena , Lasagna Manuela , Mancini Susanna , De Luca Domenico Antonio
Published: March 2022

It’s now recognized that a global climate change is taking place, leading to an increase in temperatures and a variation in precipitation regime, also affecting groundwater (GW) (Taylor et al., 2013).

In this study we want to evaluate how climate variability affects GW temperature (GWT) in the Piedmont Po plain (NW Italy).

The Piedmont Po plain covers the 27% of the whole region and it’s the most important GW reservoir of Piedmont. It consists, from top to bottom, by Alluvial deposit complex (lower Pleistocene-Holocene), that hosts a shallow unconfined aquifer, the “Villafranchiano” transitional complex (late Pliocene-early Pleistocene), that hosts a multilayered aquifer, and a Marine complex (Pliocene) hosting a confined aquifer.

For this research, 41 wells in the shallow aquifer and 20 weather stations were selected throughout the Piedmont Po plain area, and GW and air temperature parameters were analysed for the period 2010-2019.

Both GW and air temperature data (respectively, GWT and AT) were firstly studied with basic statistical analysis (mean, maxima, minima) and then with the Mann-Kendall and Theil-Sen methods to evaluate the trend.
The AT monthly mean data have a mean increase of 1,69 °C/10years; the monthly mean GWT also show a general increase in all the plain, with a mean of 0.85 °C/10years.

Then to compare water and air temperature, the Voronoi polygons method was used on QGis by centring the polygons on the weather stations. From this comparison, it was possible to highlight that in most cases (37 on 41, thus 90% of the analysed couples of temperature data) there is a greater increase in the monthly mean AT than in the monthly mean GWT.

The same behaviour was observed for the monthly minima and maxima GW and AT.

These results testify a greater resilience of GWT to climate variability. Future insights will be a detailed analysis of the factors influencing the more or less evident increase in GWT in relation to AT (e.g. depth of the water table, position of the monitoring well, position of the probe inside the well).

 

References

Taylor R.G., Scanlon B., Döll P., Rodell M., van Beek R., Wada Y., Longuevergne L.,

Leblanc M., Famiglietti J.S., Edmunds M., Konikow L., Green T.R., Chen J.,

Taniguchi M., Bierkens M.F.P., MacDonald A., Fan Y., Maxwell R.M., Yechieli

Y., Gurdak J.J., Allen D., Shamsudduha M., Hiscock K., Yeh P.J.F., Holman I.,

Treidel H. 2013. Ground water and climate change. Nat. Clim. Change 3, 322-329.

 
Application of a national soil spectrum library for the prediction of primary soil properties using machine learning – the first results
Authors: Kovács Zsófia , Mészáros János , Szűcs-Vásárhelyi Nóra , László Péter , Szatmári Gábor , Árvai Mátyás , Pásztor László
Published: March 2022

Soil observations of the Hungarian Soil Degradation Information System were carried out between 2010 and 2012 on 2000 parcels of 285 farms representing the whole territory of Hungary. 6600 soil samples were collected and measured in laboratory for chemical parameters (pH, SOM, CaCO3, NO3, P2O5, K2O, Na, Mg, SO4, Mn, Zn, Cu). The soil samples were retained and they represent a countrywide soil data bank. Very recently we initiated the spectral characterization of the stored samples. The main objective is to establish relationships between traditionally measured soil properties and spectral features to support mapping activities, which tend to rely on hyperspectral remote sensing.

The soil samples are measured with a portable spectral device, namely ASD Field Spec Pro spectroradiometer. By finalizing the spectral measurements, a nationally representative spectral library will be set up, which will contain data on (i) the above listed soil chemical parameters and (ii) reflectance values in 2151 spectral bands. This dataset provides a unique opportunity for testing the predictivity of soil chemical parameters by spectral variables.

First predictivity tests have been carried out to estimate soil organic carbon, available phosphorus and potassium by reflectance spectra. Partial Least Square Regression, Support Vector Machine, Random Forest and Artificial Neural Network were used due to their well-known performance in similar situations using 10 fold cross-validation for the validation of the developed models.

Our paper presents the elaboration of the soil spectrum library and the first results of the predictivity tests carried out between its elements.

Our research was supported by the Cooperative Doctoral Programme for Doctoral Scholarships (1015642)  and the Hungarian National Research, Development and Innovation Office (NKFIH; K-131820).
Status and Implementation of the AdriaArray Seismic Network
Authors: Kolínský Petr , Meier Thomas , Seismic Network Working Group the AdriaArray
Published: March 2022

With the advent of plate tectonics in the last century, our understanding of the geological evolution of the Earth system improved essentially. The internal deformation and evolution of tectonic plates remain however poorly understood. This holds in particular for the Central Mediterranean: The formerly much larger Adriatic plate is recently consumed in tectonically active belts spanning at its western margin from Sicily, over the Apennines to the Alps and at its eastern margin from the Hellenides, Dinarides towards the Alps. High seismicity along these belts indicates ongoing lithospheric deformation. It has been shown that data acquired by dense, regional networks like AlpArray provide crucial information on seismically active faults as well as on the structure and deformation of the lithosphere. The Adriatic Plate and in particular its eastern margin have however not been covered by a homogeneous seismic network yet.

Here we report on the status and preparation of AdriaArray – a seismic experiment to cover the Adriatic Plate and its actively deforming margins by a dense broad-band seismic network. Within the AdriaArray region, currently about 950 permanent broad-band stations are operated by more than 40 institutions. Data of 90% of these stations are currently available via EIDA. In addition to the existing stations, 385 temporary stations from 18 mobile pools are to be deployed in the region to achieve a coverage with an average station distance of about 50 – 55 km. The experiment will be based on intense cooperation between network operators, ORFEUS, and interested research groups. Altogether, more than 50 institutions will participate in the AdriaArray experiment. We will introduce the time schedule, participating institutions, mobile station pools, maps of suggested temporary station distribution with station coverage and main points of the agreed Memorandum of Collaboration. The AdriaArray experiment will lead to a significant improvement of our understanding of the geodynamic causes of plate deformation and associated geohazards.
Flood early warning can significantly mitigate monetary damage
Authors: Kreibich Heidi , Hudson Paul , Merz Bruno
Published: March 2022

Flood warning systems have a long track record of protecting human lives, but monetary damage continue to increase. Knowledge about the effectiveness of early flood warnings in reducing monetary damage is sparse, especially at the individual level. To gain more knowledge in this area, we analyse a dataset that is unique in terms of detailed information on warning reception and monetary damage at the property level. The dataset contains 4,468 damage cases from six flood events in Germany. We show quantitatively that early flood warnings are only effective in reducing monetary damage if people know what to do when they receive the warning (with at least one hour's notice). The average reduction in contents damage is 4 percentage points, which corresponds to a reduction of EUR 3,800 for the average warning recipient. This is substantial compared to the mean contents damage ratio of 21% and an absolute contents damage of 17,000 EUR. For the building damage ratio, the average reduction is 2 percentage points, which corresponds to a damage reduction of EUR 10,000. This is a remarkable reduction compared to the mean building damage ratio of 11% and a mean absolute building damage of 48,000 EUR. We also show that particularly long-term preparedness is related to people knowing what to do when they receive a warning. Risk communication, training and (financial) support for private preparedness are thus effective in mitigating flood damage in two ways: through precautionary measures and more effective emergency measures.
Foreign and domestic contributions to surface ozone among European countries
Authors: Garatachea Roger , Achebak Hicham , Jorba Oriol , Ballester Joan , Pay Maria Teresa , García-Pando Carlos Pérez
Published: March 2022

Tropospheric ozone (O3) exerts strong adverse impacts on human health, climate, vegetation, biodiversity, agricultural crop yields and thus food security. O3 is formed in the atmosphere through non-linear photochemical reactions between volatile organic compounds (VOCs) and nitrogen oxides (NOx) precursors. Currently, there are no observational methods that differentiate the origin of O3. Despite their inherent uncertainties, chemical transport models (CTMs) allow for the apportionment of the contribution of any source to O3 concentrations. The mass-transfer source apportionment method is an optimal approach to study the contribution of different sources to ozone levels.

In this study, we provide a quantitative estimation of the foreign and domestic contributions to ozone among European countries relative to the contribution of hemispheric imported ozone. We use CMAQ-ISAM within the CALIOPE air quality modelling system to simulate the O3 dynamics over Europe at a 18 x 18 km2 horizontal resolution and quantify national contributions for the ozone season from May to October during the years 2015, 2016 and 2017. We tag both O3 and its precursors, NOx and VOCs, from the different European countries, all the way through their lifetime, from emission to deposition. We discuss the results for 35 European countries, including their ozone contribution to other countries, the role of hemispheric background ozone concentrations in each country, and the changes from one year to another.
Uncovering basal melt channels on the Dotson Ice Shelf
Authors: Zinck Ann-Sofie Priergaard , Wouters Bert , Lhermitte Stef
Published: March 2022

Like most of the ice shelves in the Antarctic Amundsen Sea Embayment, intrusion of warm circumpolar deep water onto the continental shelf causes basal thinning to the Dotson Ice Shelf (DIS). Studies on other ice shelves have shown how Digital Elevation Models (DEM) of high spatial resolution can reveal basal melt patterns that are crucial in understanding the dynamics of basal melting and the underlying ocean circulation. In this study we aim to achieve high spatial and temporal resolution basal melt rates of the DIS to try to uncover new basal melt patterns which products of coarser resolution do not capture. This will be done by using the high spatial resolution Reference Elevation Model of Antarctica (REMA) and a method based on the Google Earth Engine (GEE). This allows for fast co-registration and subsequent thinning and basal melt rate analysis of the 2-m resolution REMA strips from 2010-2017. Ice shelf thinning is calculated both in a Eulerian and Lagrangian framework, the latter providing information to the basal melt rate analysis. In agreement with other studies of the DIS a melt channel is found on the western side of the ice shelf. Furthermore, our study indicates a second smaller channel, which has not been revealed by existing altimetry studies.  This suggests that high-resolution basal melt rate products could be of great importance. Furthermore, it enlightens the difficulties in coupling ocean and ice models, since such models often run on a coarser grid and therefore, they will not capture the small-scale variabilities.
Multi-pollutant assessment of health impacts of 2021 summer wildfires in eastern and central Mediterranean Basin
Authors: Zhou Bin , Knote Christoph
Published: March 2022

Ever-increasing wildfires in scale and duration have resulted in enormous human and material losses, and adverse health outcomes due to short- and long-term exposure to diverse air pollutants emitted from fires. Historically, the Mediterranean Basin, characterized by hot and dry summers, has been particularly affected by wildfires, and the situation is deteriorating as climate change worsens and the regional populations grow rapidly. To assess the health impacts due to short-term exposure to air pollution caused by the 2021 summer wildfires in eastern and central Mediterranean Basin, we demonstrate a multi-pollutant approach based on the Weather Research and Forecasting online-coupled Chemistry (WRF-Chem) model. The WRF-Chem model was used to simulate concentrations of major air pollutants such as fine particulate matter (PM2.5), SO2, NO2, and O3, in a fire and no-fire scenario. Elevated short-term exposure of the population to air pollutants were associated with excess all-cause mortality using relative risks (RRs) for individual pollutants based on previously published meta-analyses.

Our estimates indicate that the additional short-term exposure to O3, which is predicted to increase due to the wildfires, resulted in the highest number of excess deaths of 608 (95% CI: 456-771) over the entire region of investigation during the wildfire season between mid-July to early October 2021. This is followed by 270 (95% CI: 177- 370) excess deaths due to elevated PM2.5 exposure, rendering the health effect of increased O3 from wildfires larger than the effect of increased PM2.5. This is shown to be largely reasoned by the spatially more widespread impact of wildfires on O3. In contrast, the excess mortality caused by NO2 and SO2 emitted from wildfires is estimated low. This may be ascribed to the different sources of air pollutants, with NO2 a marker of traffic, while SO2 originating primarily from emissions from fossil fuel combustion, e.g., from power plants. Our study concludes with a discussion on uncertainties associated with the multi-pollutant health impact assessment and suggests a critical scrutiny of estimates based thereupon.
On the relationship between precipitation and the spatial structure of trade wind convection
Authors: Radtke Jule , Naumann Ann Kristin , Vogel Raphaela , Hagen Martin , Ament Felix
Published: March 2022

Trade wind convection organises into a rich spectrum of spatial patterns, often in conjunction with precipitation development. This raises the question of the role of precipitation for spatial organization and vice versa. Using rain radar measurements during the EUREC4A field campaign we find that precipitation rates vary mainly independently from the spatial arrangement of precipitating cells. Mean precipitation increases with the size or number of cells, as it is closely related to the precipitating area. The cells’ degree of clustering, contrary, is typically greatest where the mean cell size is large and the cell number small. Consequently, scenes with a quite different spatial structure – with larger, more clustered convective structures at one time or with more numerous and distributed convective structures at another time – can have similar precipitation rates. Could spatial organization be a process to maintain precipitation rates in very different environments? We exploit large-domain realistic large eddy simulations to investigate scenes of trade wind convection that exhibit similar precipitation rates but different spatial structures. We discuss how the environment and circulation differ in these scenes and how this might necessitate different spatial structures to rain.