bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrodynamic model of K-changes
Authors: Kaspar Petr , Marshall Thomas , Stolzenburg Maribeth , Kolmasova Ivana , Santolik Ondrej
Published: February 2023

K-changes are step-like electrostatic field changes, which occur during the final part of cloud flashes or between the return strokes in cloud-to-ground discharges. We numerically solve the full set of Maxwell’s equations coupled to the electrostatic Poisson’s equation for a given thundercloud charge structure to model the K-changes. We simulate the K-changes by a sequential increase of conductivity of the decayed vertical channel. This process creates a current pulse which attenuates as it propagates downward. We show how the modeled linear charge densities and electric potentials connected to K-changes evolve in time. We successfully compare our model with the electric field measured by a flat-plate E-change antenna with a sensor having a decay time constant of 1 s, a bandwidth of 0.16 Hz –2.6 MHz, and a sampling rate of 5 MS/s. The experimental data used for comparison with our model were obtained at KSC Florida in 2011.
Identification of Point Diffractor body placed in dipping Vertically Transverse Isotropic medium using Reverse Time Migration
Authors: Sharma Saurabh , Joshi Anand , Singh Jyoti , Pandey Mohit , Rastogi Richa , Srivastava Abhishek
Published: February 2023

Numerical modelling has been proved as an incomparable tool to understand the structure of the earth and the processes beneath the earth’s surface. Finite difference method (FDM) plays a dominant role among various numerical methods for the purpose of seismic modelling and exploration. FDM provides a comprehensible solution to the partial difference equations defining the propagations of seismic wave. These partial differential equations consist of derivatives in time and space domain. FDM can be applied by defining the elastic wave-field and model parameters at every position on a discrete mesh. Reverse-time migration (RTM) is based on exploding reflector model and it is better than other migration techniques for the interpretation of various seismic models. The present work shows the forward modelling and reverse time migration of point diffractor body placed in dipping layer of vertically transverse isotropic (VTI) medium. A 12th order space and second order time differentiation RTM scheme have been used to interpret the location and extent of a point diffractor placed in dipping layer of VTI medium. The earth model under study is of the size 1400 m x 600 m. A dipping layer and a diffractor of size 18 m x 18 m has been placed in the VTI model. The FORTRAN code developed for FDM scheme of VTI model performs various requisite studies like stability criteria, numerical dispersion and the boundary conditions within the code. The output from the FDM code are the synthetic records at surface which after processing fed as an input in the FORTRAN code developed for RTM scheme. The position and extent of the diffractor placed in the dipping VTI medium layer has been detected properly using RTM scheme. Another FORTRAN code is developed in which forward and reverse wave propagation snapshots has been cross-correlated using various cross-correlation imaging conditions. A Laplace filter is then designed to efficiently resolve the position and extent of the diffractor in the dipping VTI medium layer.
pH dependence of mineral dissolution and permeability enhancement of intermediate to basic volcanic rocks by chelating agent flooding under geothermal conditions
Authors: Salalá Luis , Argueta Jonathan , Watanabe Noriaki , Tsuchiya Noriyoshi
Published: February 2023

The use of Enhanced Geothermal Systems (EGS) has been recognized as a viable source of renewable energy in regions with high geothermal temperatures. Nevertheless, geothermal reservoirs may experience reduced permeability during exploration or operation. Research on chelating agents in geothermal environments has been widely disseminated as a complementary method to conventional methods such as hydraulic and chemical stimulation. Previous studies reported fast and significant improvements in permeability in granitic and volcanic rocks using aqueous solutions of glutamic L-diacetate acid (GLDA) under acidic conditions. However, no studies have been conducted with chelating agents applied to volcanic rocks at different pH conditions, since pH determines the ionic species in the solution, and thus, the chemical interactions taking place in a system. Furthermore, the dissolution of minerals in these conditions was not quantified for modeling purposes. In the present study, an aqueous solution of the chelating agent GLDA at various pH conditions (2-10) was applied to improve the permeability of single-fractured intermediate to basic volcanic rocks. According to the results, permeability increases about up 4.3-fold under weak acid (pH 4) conditions, while it increases about 36-fold under alkaline (pH 10) conditions, due primarily to the formation of voids caused by mineral dissolution or groundmass dissolution, respectively. Moreover, channeled samples with mirror-conditions revealed that the formation of voids at acidic conditions was as deep as 135 µm by the selective dissolution of hematite, whereas an average of 4-µm dissolution of quartz was promoted at alkaline conditions. Although the depth of voids formed in alkaline conditions is less than the case of acidic, quartz composes the matrix that surrounds the phenocrysts of volcanic rocks, promoting a preferential fluid path that improved the permeability further at alkaline conditions. This study is the first step in spreading the use of this chemical stimulation technique to different volcanic-rock geothermal systems.Keywords: EGS, chelating agents, permeability enhancement, andesitic rock, selective dissolution of minerals.
Changes in temperature-precipitation correlations over Europe: Are climate models reliable?
Authors: Vrac Mathieu , Thao Soulivanh , Yiou Pascal
Published: February 2023

Inter-variable correlations (e.g., between daily temperature and precipitation) are key statistical properties to characterize probabilities of simultaneous climate events and compound events. Their correct simulations from climate models, both in values and in changes over time, is then a prerequisite to investigate their future changes and associated impacts. Therefore, this study first evaluates the capabilities of one 11-single run multi-model ensemble (CMIP6) and one 40-member single model initial-condition large ensemble (CESM) over Europe to reproduce the characteristics of a reanalysis dataset (ERA5) in terms of temperature-precipitation correlations and their historical changes.Next, the ensembles’ correlations for the end of the 21st century are compared. Over the historical period, both CMIP6 and CESM ensembles have season-dependent and spatially structured biases. Moreover, the inter-variable correlations from both ensembles mostly appear stationary. Thus, although reanalyses display significant correlation changes, none of the ensembles can reproduce them, with internal variability representing only 30% on the inter-model variability. However, future correlations show significant changes over large spatial patterns. Yet, those patterns are rather different for CMIP6 and CESM, reflecting a large uncertainty in changes. In addition, for historical and future projections, an analysis conditional on atmospheric circulation regimes is performed. The conditional correlations given the regimes are found to be the main contributor to the biases in correlation over the historical period, and to the past and future changes of correlation.These results highlight the importance of the large-scale circulation regimes and the need to understand their physical relationships with local-scale phenomena associated to specific inter-variable correlations.
Do land-cover mosaics affect the variability of suspended sediments in rivers? The case of large river basins in Germany
Authors: Aala Safae , Basso Stefano , Borchardt Dietrich , Hoffmann Thomas , Yang Soohyun
Published: February 2023

Investigating the influence of land-cover mosaics on water quality is vital for effective management aimed at mitigating the hazard of exceeding regulatory water quality thresholds. In particular, suspended sediments in rivers can easily jeopardize aquatic ecological functions, by transporting significant amounts of pollutants along flow paths. Nonetheless, a relationship between land-cover mosaics and suspended sediment dynamics remains unclear due to the complexity of interactions and feedbacks between geomorphological and hydrometeorological conditions in diverse river basins. Here, we aim to analyse the linkages of landscape metrics describing the spatial patterns of land-cover with the (power-law) rating exponent of suspended sediment concentration SSC and river discharge Q (i.e. SSC = aQb), as an integral property of sediment dynamics. For three major river basins in Germany (Elbe, Rhine, and Weser covering about 66 % of total German territory), the sediment rating parameters are extracted at high flows. Moreover, thoroughly selected descriptors are computed to characterize the composition and spatial configuration of land cover as well as topographic and hydrogeological conditions (e.g., temporal variability in Q and flashiness index). Preliminary results show the existence of correlations between the spatial organization of land cover along the river network and the rating exponent b at high flow regime. In particular, they indicate that high increase in suspended sediments at high flows is generated in catchments with more homogeneous land cover and sediment sources distributed near large streams. Our findings can aid policymakers and watershed managers in making informed decisions and taking necessary actions to improve current and future river water quality issues caused by suspended sediments.
Overfertilization combined with flooding irrigation contributes to soil nutrient accumulation and pH decline in greenhouse vegetable production systems
Authors: Wan Li , Lv Haofeng , Xia Longlong , Lin Shan , Butterbach-Bahl Klaus
Published: February 2023

Conventional overfertilization combined with flooding irrigation is common practice in solar greenhouse vegetable production systems in Eastern China. However, how these practices may affect soil nutrient concentrations remains understudied. Here we report on a regional soil sampling study in Shouguang county, which is the major and pioneer area of greenhouse vegetable production in China. In our study, we measured soil nutrient concentrations (mineral N, Olsen-P, and available K) as well as soil physico-chemical parameters (e.g. pH, SOC) down to 3 m soil depth in 60 greenhouses differing in years since establishment (5, 10, and 20 years) and compared those to nutrient concentrations in 20 adjacent arable fields. We found that in greenhouse soils compared to soils of adjacent arable fields: (1) soil nutrients were significantly elevated in the topsoil (0-30 cm), while nutrient concentrations in the subsoil were much lower and differences between greenhouse and arable soils diminished; (2) N:P:K ratios were imbalanced towards P and K as these elements are not easily leached as N; (3) the soil pH is decreased. After about 20 years of continuous greenhouse vegetable production, the topsoil pH was lowered by 0.92 ± 0.07 units. Our study shows that overfertilization combined with flooding irrigation has serious impacts on soil chemistry and soil nutrient concentrations. The observed nutrient imbalances are dramatic and indicate that e.g. P and K fertilization may not be needed for years to come. Also the observed decline of the significant decrease in the soil pH of calcareous soil indicates, that the soil pH carbonate buffer system is at the edge to break down, with unknown consequences for soil fertility. These facts strongly suggest that unnecessary excessive fertilizer and irrigation water applications for producing vegetables in solar greenhouse systems should be stopped and replaced with more sustainable production methods, e.g. drip fertigation with reduced fertilizer application.
Water quality trends and the drivers in livestock-intensive regions: Results from 20 years of catchment monitoring in Norway
Authors: Liu Jian , Bechmann Marianne , Øgaard Anne Falk
Published: February 2023

Intensive livestock production has raised enormous water quality concerns in Europe and elsewhere around the world. There is a need to examine long-term water quality trends and understand the drivers for the trends based on detailed catchment monitoring. Given orthophosphate-phosphorus (P) is highly relevant to eutrophication in freshwater lakes and rivers, we monitored its concentration and load trends in streamwater of a livestock-intensive catchment in western Norway for a 20-year period, using the approaches of continuous flow measurements and flow-proportional composite water sampling. Precipitation and catchment-level soil P balance, as well as field-level measurements of soil P status, were monitored to examine the drivers. Trend analyses showed that both annual mean P concentration (range: 0.05–0.14 mg L-1; mean: 0.08 mg L-1; p = 0.001) and annual P load (range: 0.35–1.46 kg ha-1; mean: 0.65 kg ha-1; p = 0.0003) increased significantly over the 20-year monitoring period. The mean concentrations were positively correlated with cumulative soil P surplus (R2 = 0.55, p = 0.0002). Although discharge of the streamflow significantly affected annual P load, the P surplus appeared to be an even more important factors. The study highlights that long-term P surplus plays a critical role in influencing orthophosphate-P concentration and loads in livestock-intensive regions. There is a big challenge to reduce the P surplus, which however may be achieved through integrated strategies such as reducing livestock density, manure refinement and transport to crop-intensive regions, improving livestock feeding management, and increasing crop P removal.
Microseism and Medicane Apollo: a new approach to investigate the Mediterranean extreme weather events
Authors: Borzì Alfio Marco , Minio Vittorio , Cannavò Flavio , Cavallaro Angelo , D'Amico Sebastiano , De Plaen Raphael , Gauci Adam , Lecocq Thomas , Nardone Gabriele , Orasi Arianna , Picone Marco , Cannata Andrea
Published: February 2023

Microseism is the most continuous and ubiquitous seismic signal on the Earth and is caused by the interaction between the atmosphere, the hydrosphere and the Solid Earth. In literature, there are several studies that deal with the relationship between microseism and cyclonic activity considering in particular hurricanes, tropical cyclones and typhoons. However, the relationships between microseism and the small-scale tropical cyclones that occur in the Mediterranean Sea, called Medicanes, have never been analysed. For this reason, we considered the Medicane Apollo, which developed in the Ionian Sea and impacted the eastern part of Sicily during the period 25th October to 5th November 2021 causing heavy rainfall (> 400 mm/48h), strong wind gusts (104 km/h) and violent sea waves (significant wave height > 3.5 m). Furthermore, the heavy rainfall induced by the presence of Apollo, caused damage to infrastructure and agriculture forcing the Sicilian regional government to declare a state of emergency for 32 municipalities (in the provinces of Catania, Messina, Siracusa and Ragusa) that were mostly affected by the Medicane Apollo.In this work, we analysed the microseism signal recorded by 78 seismic stations installed in South Italy, Malta and Greece coastline during the period under investigation. To obtain information about the significant wave heights, we consider the data obtained by hindcast maps and four wavemeters buoys. The spectral and amplitude analysis allowed us to obtain information about the space-time variations of the microseism amplitude and in addition, we were able both to differentiate the seismic stations that perceive Apollo (stations installed close to the Ionian Sea), the seismic stations that do not perceive the medicane (stations installed close to the Tyrrhenian sea) and the microseism bands influenced by the presence of the Medicane Apollo. Moreover, we tracked the position of the Apollo by using two different methods: i) grid search method based on the seismic amplitude decay using the 78 seismic stations first mentioned and ii) array technique by 15 seismic stations installed on Etna which may be considered an array thanks to their spatial distribution and geometry. We obtain a good match between the real positions of the Medicane Apollo derived from satellite images and the positions computed by the two analysis methods. This work shows that it is possible to extract information about the Mediterranean extreme meteo-marine events from microseism, a seismic signal that until not long ago was considered as noise, both for monitoring and research purposes.
Diurnal Temperature Variations and Thermal Tides in the Martian Atmosphere Observed by EMIRS during EMM Primary Mission
Authors: Fan Siteng , Forget Francois , Smith Michael , Guerlet Sandrine , Badri Khalid , Atwood Samuel , Young Roland , Edwards Christopher , Christensen Philip , Deighan Justin , Al Matroushi Hessa , Bierjon Antoine , Liu Jiandong , Millour Ehouarn
Published: February 2023

We present results of diurnal temperature variations and thermal tides in the Martian atmosphere using observations obtained by the Emirates Mars InfraRed Spectrometer (EMIRS) onboard the Emirates Mars Mission (EMM) Hope probe during its primary mission. The novel orbit design of the spacecraft allows a full geography and local time to be covered every 10 Martian days, approximately ~5° of solar longitude (LS). Diurnal temperature variations are derived for the first time on a planetary scale without any significant gaps in local time or interference from seasonal changes. Contributions of thermal tides are then analyzed. The dataset of the EMM primary mission covers one Martian Year (MY) starting from MY 36 LS=49°. Seasonal changes of the diurnal temperature variations and thermal tides are investigated. The results show good agreements with predictions provided by the Mars Planetary Climate Model (PCM), but with noticeable differences in the phases and wavelengths of the thermal tides. This work provides valuable information on understanding the diurnal climate of Mars, and inspires future advances of Mars GCMs.
Dynamical systems approaches to climate response and climate tipping
Authors: von der Heydt Anna
Published: February 2023

The currently ongoing climate change and the debate about possible measures to be taken to limit the consequences of climate change, requires to know and understand the future response of the climate system to greenhouse gas emissions. Classical measures of climate change such as the Equilibrium Climate Sensitivity (ECS) are inherently linear and unable to account for abrupt transitions due to (interacting) tipping elements.In this presentation I will discuss more general notions of climate sensitivity defined on a climate attractor that can be useful in understanding the response of a climate state to changes in radiative forcing. For example, a climate state close to a tipping point will have a degenerate linear response to perturbations, which can be associated with extreme values of the ECS. While many identified tipping elements in the climate system are regional and may have no direct impact on the global mean temperature, cascades of tipping elements can potentially have an impact, initiated by the threshold of the leading tipping element in a cascade.
Exploration of Lunar magnetic fields with dynamo thermally and tidal heating-driven rheology model
Authors: Zhu Bojing
Published: February 2023

The planetary magnetic field, caused by convective currents in the cores and linking thermal and interior, is a fundamental way to determine the angular momentum exchange and secular variation in the core motions & core-mantle coupling system. But understanding the high temperature-pressure (e.g., ~5000 °C, 135~330 Gigapascals) rheology fluid flows in planetary cores is a tremendous interdisciplinary challenge. The fine-structure investigation requires understanding the fundamental rheology fluid dynamic involving turbulence and rotation from continuing hydro-dynamo-kinetic coupling scales well beyond the present traditional partial differential equation virtual test.The lunar magnetic field is believed not currently to possess a feeble global magnetic field and can be ignored when exploring the solar-flare CME-induced solar storm transplant on the lunar surface. The hypothesis holds that the crustal magnetizations were acquired early in lunar history when dynamics were still operating. At that time, the dynamo magnetic fields were generated by the thermochemical convection of electrically conductive alloy metal liquid within lunar cores and reduced with the convection cooling process. The turbulence mechanical stirring of lunar core rheology fluids and perturbations by the tidal effect and orbital precession can contribute to sustaining dynamo fields.With the supporting observations of China’s lunar and deep space exploration in recent years, it has become possible to re-estimates the past magnetic field by considering combining the tidal heating induced dissipation from viscous friction associated with the differential procession at a different angle and dynamo action (the non-ideal plasma; inner core-outer core-mantle; warm dense matter; liquid iron alloy; chemical-geological properties; density-temperature-pressure) together again.In this work, based on the newly developed optimization methodology and numerical algorithm of relativistic hybrid particle-in-cell and lattice Boltzmann (RHPIC-LBM version 1.1.2), we establish the 3D lunular magnetic field modeling with combined rheology dynamo thermally and tidal-heating of its lunar cores and investigate the history of magnetic field evolution; And figure out the effect of tidal heating in the deepest lunar mantle,  and offer a possible unprecedented window on this intermediate state of rheology matter and providing a new virtual testing ground for dense rheology plasma theories.
Soil nitrogen pool and its fractions in German apple orchards under organic vs conventional management
Authors: Sut-Lohmann Magdalena , Grimm Mark , Heinrich Martina , Baig Sawdha , Raab Thomas
Published: February 2023

Agriculture is a massive production with intensive practices, like large variety of agro-chemicals, heavy machinery etc., that support food security. However, recently more and more attention is given to food safety in relation to human, environment and soil health. An alternative strategy is organic agriculture that avoids the use of synthetic chemicals and maintain the sustainable food production. But organic farming cannot completely support the worlds foods demand, so adaptation is needed to reach a sustainable productivity while protecting the environment.Soil nitrogen (N) pool consists of inorganic and organic fractions. Inorganic and a part of labile organic N is a primary nutrient source for plants and microbes. Different nitrogen fractions play various roles in soil ecosystems and can be strongly influenced by the site management. Soil nitrogen transformations are directly relatable to plant health, thus strongly influence healthy functioning of soil ecosystem. Knowledge about the soil nitrogen pools is necessary to assess the proper and sustainable fertilization approaches under various management practices. To evaluate various N fractions, fresh soil samples were sampled (20 cm depth, row and near tree) at 8 conventional and 8 organic apple farms (Germany: states of Brandenburg, Saxsony and Saxony-Anhalt), with various age, locations and management practices. Soil samples were analyzed using CNS, Kjeldhal digestion, spectrophotometer and chloroform fumigation. The aim of this study is to compare the total and labile (particulate organic, microbial biomass and water extractable organic) N fractions in soil samples considering various site management approaches, topography and climate. 
Transport of Polylactic Acid (PLA) Microplastics in Agricultural Soils under Simulated Rainfall Events - Analyzing Surface Water Runoff as an Environmental Pathway
Authors: Sinha Ray Saunak , Zumr David , Dostal Tomas
Published: February 2023

Due to the ecological risk posed by plastic pollution, biodegradable plastics (BDPs) usage in agriculture has gained attention as an alternative to conventional plastics. However, agricultural soil remains a major reservoir of microplastics (MPs) in today’s global environment. Given the persistence of MPs, few studies have focused on the fate and transport of conventional MPs from agricultural topsoil. However, understanding the transport of biodegradable MPs is largely unknown. The aim of this study is to analyze the erosion and transport behavior of biodegradable polylactic acid (PLA) MPs (size 250 – 300 μm) under simulated heavy rainfall events on fallow and crusted agricultural soils. The experiment used fluorescent PLA filament to obtain the MPs. Based on the fluorescent property of the PLA MPs, a simple, reliable, and cost-effective method using darkroom photography under a 365nm UV lamp, and an Image J script was developed for quantification. The study was conducted on three plots (1m × 1m) of loamy soil at an agricultural field in the Czech Republic. A concentration of 4 g m-2 of PLA MPs was incorporated into the top 5 cm of the soil in each plot. Rainfall simulations with an intensity of 60 mm h-1 were carried out twice within one week in April 2022. The results showed a general depletion of biodegradable PLA MPs in the delivered sediment. Eroded sediments showed mean enrichment ratios of 0.59 ± 0.05 in the fallow plot and 1.45 ± 0.37 in the crusted plot. Higher MP enrichment and sediment delivery were observed on crusted soil compared to fallow soil, suggesting a more conservative erosion and transport for the latter. Overall, our study highlights that a relatively high-density biodegradable MP, such as PLA, tends to remain within the topsoil and is negligibly affected by rainfall-induced surface runoff and very low infiltration capacity.
Interplanetary magnetic field effects on the magnetopause location
Authors: Aghabozorgi Nafchi Maryam , Němec František , Pi Gilbert , Němeček Zdeněk , Šafránková Jana , Grygorov Kostiantyn , Šimůnek Jiří
Published: February 2023

We use a large set of nearly 15,000 subsolar magnetopause crossings identified in the THEMIS A-E, Magion 4, Geotail, and Interball-1 satellite data to analyze the effect of interplanetary magnetic field (IMF) on the location of the magnetopause. Differences between the observed and empirical model magnetopause distances are used to account for the magnetopause distance variations due to the changes in the solar wind dynamic pressure. It is shown that not only the IMF Bz component but also the IMF clock angle has a significant effect on the magnetopause location, which is not included in traditional empirical models. Additionally, IMF By component can cause considerable dawn-dusk asymmetry in the shape of the magnetopause at times of very low Alfvén Mach numbers (MA<4). Both the magnitude and orientation of the IMF By component seem to affect the magnetopause distance. The obtained results are consistent with a global MHD model run at the Community Coordinated Modeling Center (CCMC).
The design of user-centred seismic risk maps – the Swiss case
Authors: Dallo Irina , Schnegg Laura Noemi , Marti Michèle
Published: February 2023

Maps are a widely used mean to communicate spatial hazard and risk information to the public, with the aim to increase individual risk awareness. The use of maps is triggered by scientific evidence that maps are the format most preferred by the public. However, past studies have shown that, if not well designed, maps are often misinterpreted and can trigger wrong attitudes. Thereby, the different elements such as the icons on the map, the chosen layers, the legend, or the used color scale influence the comprehension of the information on the map. In the context of natural hazards, and more precisely earthquakes, research has so far mainly focused on the design of hazard maps, and little is known about the effective design of risk maps. We thus assessed how to design understandable, useful, and actionable seismic risk maps for the public.To this end, we conducted a transdisciplinary project in Switzerland by ensuring an interdisciplinary co-production of the map and testing it with the public. First, we – an interdisciplinary group at the Swiss Seismological Service at ETH Zurich – co-designed different versions of the seismic risk map varying the color scale and legend format. Second, we tested these versions with a public survey (between-subjects experiment); representative for the German- and French-speaking part of Switzerland. We assessed which map version was correctly interpreted, perceived as useful, increased people’s risk perception, and triggered people to take protective actions. Further, we analyzed whether certain social groups (e.g., house owners) had different preferences, risk perception, or intentions to take action.At the conference, we will present the preliminary results of the survey and provide evidence-based recommendations on how to design user-centred seismic risk maps. This should support institutions responsible for public communication to add seismic risk maps to their products to effectively inform the public about seismic risks and, in turn, increase their risk awareness and intention to take protective actions. This project has received funding from the Federal Office for the Environment (FOEN), the Federal Office for Civil Protection (FOCP), and the Swiss Federal institute of Technology Zurich (ETH Zurich).
Coregionalization models of geophysical data for site effect assessment at Anse-à-Veau, Haiti
Authors: Havenith Hans-Balder , Dorival Valmy , Guerrier Kelly , Ulysse Sophia
Published: February 2023

The multivariate generalization of the kriging, in geostatistical analysis, called cokriging makes it possible to take advantage of the relationships between several variables. The information carried by a secondary variable may improve the precision of the estimation of the main variable. The multivariate structural model between the variables is then built from the spatial joint analysis of the data which can be realized by coregionalization linear models.  The present study aims at assessing the site effects from the results of multivariate analysis of seismic data collected at Anse-à-Veau, a municipality in the Nippes Department of Haiti, characterized by a relatively high seismic activity – during the measurement campaign in August 2021 this region had been hit by the 2021 Nippes Earthquake. The surveys carried out include ambient noise and seismological recordings, seismic tests as well as electrical resistivity measurements along profiles. The two first were processed, respectively, in terms of Horizontal to Vertical Spectral Ratios (HVSR) and Standard Spectral Ratios (SSR), the seismic tests both as Seismic Refraction Tomography (SRT) and by Multichannel Analysis of Surface Waves (MASW) and the last measurements as Electrical Resistivity Tomography (ERT). In total, more than 100 HVSR recordings, 7 115m-long seismic profiles and 8 ERT profiles have been completed. All related results were then compiled within one multi-data (including also geological, geomorphic and geomechanical information) 3D geomodel and submitted to a spatial analysis. The coregionalization modelling applied within this analysis is expected to take advantage of the relationships between the different type of seismic data in order to better estimate the potential site effects in the study area.Keywords: coregionalization model, site effects, multi-geophysics, geomodelling, Haiti.    
Links between climate tipping elements: A story of ice, overturning and trade winds
Authors: Falkena Swinda , von der Heydt Anna
Published: February 2023

Within the earth system several tipping elements exist. It is important to understand the links between these tipping elements, as a critical transition in one element could lead to tipping of another. Here, we study the links between some of these tipping elements in CMIP6 data. The starting point is the Atlantic Meridional Overturning Circulation (AMOC), whose collapse would have world-wide impacts and for which nearly all climate models show a decrease in the strength. In the Northern Hemisphere it would induce wide-spread cooling, impacting both sea-ice and the Greenland Ice Sheet (GIS). The corresponding changes in the global distribution of heat impact the atmospheric circulation. Where the response of the trade winds in the Atlantic is still relatively similar between models, this is not the case for the Pacific resulting in large uncertainty in the El Nino Southern Oscillation (ENSO) response.To understand the effect of the AMOC on ENSO and other tipping elements, we consider the effect it has on the physical processes involved. For example, to study the effect of the AMOC on ENSO we consider its effect on the Pacific trade winds and other physically relevant variables. This aids in better understanding the consequences of an AMOC collapse and the potential for tipping cascades.
Study of the urban effect of Paris on several thunderstorm cases in 2022, using hectometric ensemble simulations
Authors: Forster Arnaud , Masson Valéry , Augros Clotilde
Published: February 2023

Climate change and a rapidly increasing urban population make cities more vulnerable to hazardous weather events. The need for a better understanding of meteorological processes and an improvement of the weather prediction system in an urban environment is crucial to mitigate these impacts and protect the population. The “Paris Olympics” international Research and Demonstration Project, endorsed by WMO, aims at improving meteorological research in urban meteorological processes and weather forecasting systems at 100m resolution. It mainly focuses on extreme weather events in urban areas such as urban heat islands and thunderstorms. Several study cases have been proposed. They are golden cases observed during the PANAME2022 field campaign in Paris and they represent interesting weather situations to test numerical weather prediction capacities.The objective of this study is to investigate through the selected cases, the influence of Paris’s urban environment on thunderstorms. An ensemble of hectometric simulations is built using the Meso-NH research atmospheric model initialized and forced by the members of the AROME-EPS ensemble prediction system which has a 1.3 km horizontal resolution. For each case, two sets of ensemble simulations are performed; to identify the main processes driving the interactions between urban environment and thunderstorms: one with a fine-scale surface description of the city (using a multi-layer urban scheme) and another one where the urban surface is replaced with vegetation.The first results show that it remains challenging to correctly simulate the location of thunderstorms. Nevertheless, the ensemble technique combined with urban and non-urban city description is effective to discriminate random effects from real trends on  the urban environment impacts on thunderstorms.
Understanding the role of forest fires in urban pollution in São Paulo, Brazil
Authors: Oliveira Maria , Miranda Regina Maura
Published: February 2023

The air quality in the Metropolitan Area of São Paulo (MASP) is influenced by local sources of pollution, mainly from vehicles and industries, but there is a concern about the role of remote sources in the concentration of particulate matter, such as biomass burning plumes, which occur mainly in the interior regions of Brazil. During the dry period (mainly between July and October), the central region of Brazil suffers from biomass burning, which releases large quantities of gases and particles into the atmosphere and not only affects nearby cities, but also regions hundreds of kilometers away, as is the case of the city of São Paulo.This study aimed to evaluate the concentration of PM10, PM2.5and Aerosol Optical Depth (AOD) between 2005 and 2022, identifying seasonal variations, spatial distribution, frequency, meteorological influences, and the main sources of the aerosol, including understanding and quantifying the impact of burning events on air quality in the MASP.The surface pollutant data, meteorological data, and AOD data were provided, respectively, by: São Paulo Environmental Company (CETESB; https://cetesb.sp.gov.br/ar/qualar/),Institute of Astronomy, Geophysics andAtmospheric Sciences (IAG/USP; http://www.estacao.iag.usp.br/)and Aerosol Robotic Network (AERONET;https://aeronet.gsfc.nasa.gov/).The results indicate a downward trend for aerosol, since several public policies were implemented in the period, but the values are still far above the standards recommended by the World Health Organization (WHO), especially in the winter months (June-September), due to meteorological conditions. Burning events that affect the MASP (more frequent in September) contribute to the increase of particle concentrations at the surface,as well as to the increase of AOD, related to the frequency of northwest wind direction in these eventsandalsoto the number of fire spots in the country.
Irrigation quantification through backscatter data assimilation with a buddy check approach
Authors: Busschaert Louise , Bechtold Michel , Modanesi Sara , Massari Christian , Brocca Luca , De Lannoy Gabriëlle J. M.
Published: February 2023

Irrigation is an important component of the terrestrial water cycle, but it is often poorly accounted for in models. When included, irrigation often relies on simplistic assumptions such as soil moisture deficit approaches. In the last years, methods have been developed to detect and quantify irrigation by making use of satellite remote sensing data. Recent developments have attempted to integrate satellite data and land surface models via data assimilation (DA) to (1) detect and quantify irrigation, and (2) better model the related land surface variables such as soil moisture, vegetation, and evapotranspiration. In this study, different synthetic DA experiments are tested to advance satellite DA for the estimation of irrigation. We assimilate synthetic Sentinel-1 backscatter observations into the Noah-MP model coupled with an irrigation scheme. When updating soil moisture, we found that the DA sets better initial conditions to trigger irrigation in the model. However, large DA updates to wetter conditions can inhibit irrigation simulation. Building on this limitation, we propose an improved DA algorithm using a buddy check approach. The method still updates the land surface, but now the irrigation trigger is not based on the evolution of soil moisture, but on an adaptive innovation outlier detection, making the trigger observation-based.The new method was tested with different levels of model and observation error. For mild model and observation errors, the DA outperforms the model-only 14-day irrigation estimates by about 30% in terms of root-mean-squared differences, when frequent (daily or every other day) observations are available. The improvements can surpass 50% for high model errors. However, with longer observation intervals (7 days), the system strongly underestimates the irrigation amounts. White noise in the signal has a milder impact on the performance, reducing the improvement by 10% compared to the assimilation of perfect observations. The method is flexible and can be expanded to other DA systems and to a real-world case.
Large scale influence on extreme precipitation
Authors: Fauer Felix S. , Rust Henning W.
Published: February 2023

Extreme precipitation is one of the biggest climate-change-related threats in middle Europe with flooding events leading to high death tolls and huge existential and financial losses. Evaluating how the probability of such events changes with respect to climate change can help preventing casualties and reducing impact consequences. Our analysis aims for the creation of Intensity-Duration-Frequency (IDF) curves which describe the major statistical characteristics of extreme precipitation events (return level, return period, time scale). They provide information on the probability of exceedance of certain precipitation intensities for a range of durations and can help to visualize how extreme the event for different durations is. We modeled the underlying distribution of block maxima with the Generalized Extreme Value (GEV) distribution. The scarce availability of data, a core problem when modeling extremes, can be addressed by using the available data more efficiently. Therefore, including maxima from different measurement durations is useful for (1) gathering more information from the data and (2) estimating return periods for different time scales with a consistent modeling approach. Duration-dependence is implemented directly into the parameter estimation (Koutsoyiannis et al., 1998) and enables a consistent model, i.e. without quantile-crossing.To include large-scale information, each of the GEV parameters was modeled with a linear dependence on the large-scale variables temperature, blocking situation, humidity, year and North Atlantic oscillation (NAO), all spatially and monthly averaged. We show that the probability of extreme events increases with time, temperature and humidity over all seasons (summer, winter, whole year). The effects of blocking situation and NAO depend on the season with positive NAO leading to stronger events only in winter and blocking leading to stronger events only in summer and vice versa. A cross-validated model verification shows improvement over a reference model without large-scale information. This study is conducted on precipitation data from ~200 stations across Germany with temporal measurement resolutions from minutes to days.
We can automatically classify river geomorphic features from Sentinel 2 images - but what about their uncertainty?
Authors: Bozzolan Elisa , Brenna Andrea , Bizzi Simone , Surian Nicola
Published: February 2023

Machine learning models that automatically delineate river geomorphic features on Sentinel 2 (S2) images have the potential to provide a weekly monitoring of their dynamics and a better understanding of the underlying river channel processes. The accuracy (e.g. 95%) of these feature delineations is generally assessed by quantifying the percentage of pixels of known nature correctly classified by the model. However, the pixels used for such calculations are often sampled within the classified satellite image (with a resolution of 10m of larger) laying shadow on the real, relative extent of the misclassified pixels (e.g. the remaining 5%) usually located at the borders between features, which unavoidably lead to the under or overestimation of one feature for another. This issue raises questions on the real extent of the geomorphic features measured or on the true geomorphic temporal change that can be detected. In this work, we identified the nature and extent of the misclassified pixels on S2 images of a section of the river Sesia (North Italy) by comparing the classes of water, sediment and vegetation automatically delineated by a machine learning model with those manually delineated in higher resolution images: Planet at 3m, and aerial orthophotos at 0.3m resolution. Assuming the orthophoto as error-free, we found that: (1) in both S2-based automatic classification and Planet-based manual classification, water is underclassified and that (2) the error of the misclassified area is insensitive to the spatial resolution, with the water class ~20% underestimated in both the S2 (10m) and the Planet (3m). By considering the period between 2018 and 2022, we also demonstrated that the active channel (water + sediment) trajectory assessed by using the S2 images on a weekly basis is comparable to the trajectory determined using the Planet or aerial orthophotos on a yearly basis. However, the frequent image acquisition of the S2 was able to capture the river corridor abrupt response and prompt recovery to a major flood in 2019, overlooked in the other two image sources. This work therefore shows that once the spatial uncertainty is quantified (e.g. 20% for the water class), the frequent image acquisition of the S2 provides a robust reconstruction of the river geomorphic trajectories as well as a better interpretation of the river processes, in particular recognising transient states in between significant events.
Model Resolution Effects on ENSO and its Teleconnections
Authors: Williams Ned , Scaife Adam , Screen James
Published: February 2023

The El Niño-Southern Oscillation (ENSO) influences climate on a global scale and is a source of long-range predictability. Accurate modelling of the impact of ENSO requires accurate representation of teleconnections as well as of ENSO itself. We consider a set of CMIP6 models and assess the effect of increasing model resolution on ENSO and its boreal winter teleconnections. The spatial structure, strength and asymmetry of both ENSO and its teleconnection to the extratropical North Pacific are considered. We find evidence of an improved El Niño teleconnection in high resolution models, but this effect is weaker for La Niña. We aim to establish whether ocean or atmospheric resolution is the primary driver of resolution-based trends, and we evaluate the relevance of mean state biases on these trends. 
Mid-XIX Century Estuary SST Time Series Recorded in the Venice Lagoon
Authors: Rubino Angelo , Rubinetti Sara , Zanchettin Davide
Published: February 2023

Sea surface temperature (SST) is of paramount importance for comprehending oceandynamics and hence the Earth’s climate system. Accordingly, it is also the most measuredoceanographic parameter. However, until the end of the XIX century, no continuous time series ofSST seem to exist, with most of the available data deriving from measurements on ships. Here,we present a continuous record of surface water measurements retrieved thrice daily in the Venice lagoon,in the northeastern part of the Italian peninsula, from June to August 1851 and 1852. To the best of ourknowledge, these data represent the oldest SST time series of the entire world ocean. Themeasurements were performed by immersing a Réaumur thermometer a few meters deep in thelagoon water at 8 a.m., 12 p.m., and 8 p.m. Despite several limitations affecting these data (e.g.,lacking information regarding the exact water depth where measurements were performed andinstrumental metadata), they are of utmost significance, as they put many decades backward thedate of the development of a fundamental aspect of oceanographic observations. Moreover, thedata were collected close to the Punta della Salute site, where actual sea water temperaturemeasurements have been performed since 2002. Therefore, a unique comparison betweensurface water temperatures within the Lagoon of Venice across three centuries is possible.