bluuebunny/crossref_metadata_2025 huggingface dataset:
GLEAM-HR: current state and future prospects
Authors: Hulsman Petra , Koppa Akash , Miralles Diego
Published: February 2023

Reliable, high-resolution evaporation data are needed for large-scale agricultural and hydrological management applications. However, field observations are too sparse to monitor large regions continuously, and satellite-based datasets are often too coarse or restricted to specific regions. An example of such satellite-based datasets is the Global Land Evaporation Amsterdam Model (GLEAM)1. GLEAM is a state-of-the-art, global evaporation product which has been widely applied over the past decade in climate studies. However, due to its coarse original resolution (0.25 degree), it has not been used in hydrological and agricultural applications until recently2. Ongoing developments have culminated in a high-resolution (HR, i.e. ~1 km) GLEAM version covering the Mediterranean region, over the 2015–2021 period. The Mediterranean region is characterised by intense human activities, different hydroclimatic conditions ranging from temperate cold to tropical, and intense seasonal rainfall at irregular spatial distributions. As a result, the region is prone to droughts, floods and landslides, making it an ideal testbed for GLEAM-HR. Here, we present current activities and future plans regarding this new dataset. Prospective plans include the extension from the Mediterranean domain to the entire European and African continents, by adopting a series of developments that have so far been confined to the coarse-scale application of the model. These include modifications in the interception module3, the incorporation of groundwater effects4, and the use of deep learning for the estimation of transpirational stress5.
 
 
1 Miralles, D. G., Holmes, T. R. H., De Jeu, R. A. M., Gash, J. H., Meesters, A. G. C. A., and Dolman, A. J.: Global land-surface evaporation estimated from satellite-based observations, Hydrol. Earth Syst. Sci., 15, 453–469, https://doi.org/10.5194/hess-15-453-2011, 2011. 2 Martens, B., De Jeu, R. A. M., Verhoest, N. E. C., Schuurmans, H., Kleijer, J., and Miralles, D. G.: Towards estimating land evaporation at field scales using GLEAM. Remote Sens., 10, 1720, https://doi.org/10.3390/rs10111720, 2018.3 Zhong, F., Jiang, S., van Dijk, A. I. J. M., Ren, L., Schellekens, J., and Miralles, D. G.: Revisiting large-scale interception patterns constrained by a synthesis of global experimental data, Hydrol. Earth Syst. Sci., 26, 5647–5667, https://doi.org/10.5194/hess-26-5647-2022, 2022.4 Hulsman, P., Keune, J., Koppa, A., Schellekens, J., and Miralles, D. G: Incorporating plant access to groundwater in existing global, satellite-based evaporation estimates, ESS Open Archive, https://doi.org/10.1002/essoar.10512478.1, in review, 2022.5 Koppa, A., Rains, D., Hulsman, P., Poyatos, R., and Miralles, D. G.: A deep learning-based hybrid model of global terrestrial evaporation, Nat. Commun., 13, 1912, https://doi.org/10.1038/s41467-022-29543-7, 2022.
A new and uniformly processed GNSS-velocity field for Turkey
Authors: Özbakır Ali Değer , Kurt Ali Ihsan , Cingöz Ayhan , Ergintav Semih , Doğan Uğur , Özarpacı Seda
Published: February 2023

The Anatolia–Aegean domain represents a broad plate boundary zone, with the deformation accommodated by major faults bounding quasi-low deforming units. The main characteristics of the Anatolia-Aegean deformation were identified using a GNSS-derived velocity field. Recent advancements in GNSS measurements and networks have improved the spatial resolution of the Anatolia-Aegean deformation field, however, for a better understanding of the deformation, interstation distances that are smaller than fault-locking depth and consistent data processing using a single reference system are needed. Our goal is to address this gap and produce a uniform velocity solution.In this study, we processed the time series of 836 stations, of which 178 are published for the first time with sub-millimeter accuracy. With a period of up to 28 years, we present the most accurate velocity field with increased spatial and temporal resolution and homogeneity. We used the improved coverage of the velocity field to calculate strain accumulation on the North and East Anatolian Faults.  Modeled slip rates vary between 20 and 26 mm/yr and 9.7 and 11 mm/yr for the North and East Anatolian faults, respectively. Further analysis of the data can help better understand the kinematics of continental deformation in general, and test outstanding hypotheses about the kinematics and dynamics of the Anatolia - Aegean domain in particular.
Peeking Inside Hydrologists' Minds: Comparing Human Judgment and Quantitative Metrics of Hydrographs
Authors: Gauch Martin , Kratzert Frederik , Gilon Oren , Gupta Hoshin , Mai Juliane , Nearing Grey , Tolson Bryan , Hochreiter Sepp , Klotz Daniel
Published: February 2023

Everyone wants their hydrologic models to be as good as possible. But how do we know if a model is accurate or not? In the spirit of rigorous and reproducible science, the answer should be: we calculate metrics. Yet, as humans, we sometimes follow a scheme of "I know a good model when I see it" and manually inspect hydrographs to assess their quality. This is certainly a valid method for sanity checks, but it is unclear whether these subjective visual ratings agree with metric-based rankings. Moreover, the consistency of such inspections is unclear, as different observers might come to different conclusions about the same hydrographs.In this presentation, we report a large-scale study where we collected responses from 622 experts, who compared and judged more than 14,000 pairs of hydrographs from 13 different models. Our results show that overall, human ratings broadly agree with quantitative metrics in a clear preference for a Machine Learning model. At the level of individuals, however, there is a large amount of inconsistency between ratings from different participants. Still, in cases where experts agree, we can predict their most likely rating purely from qualitative metrics. This indicates that we can encode intersubjective human preferences with a small set of objective, quantitative metrics. To us, these results make a compelling case for the community to put more trust into existing metrics—for example, by conducting more rigorous benchmarking efforts.
Flood forecasting for everywhere-PUB in flood forecasting
Authors: Skaugen Thomas , Mengistu Zelalem , Peerebom Ivar , Wong Wai
Published: February 2023

In this study the Prediction in Ungauged Basins has been taken very literally in that we present a system that enables setting up a rainfall-runoff model, the Distance Distribution Dynamics (DDD) model for any catchment in Norway. The system can be used in operational flood forecasting since hydrological simulation results for an arbitrary catchment are obtained in a few minutes. A GIS map tool is used to calculate catchment boundaries, a hypsographic curve and other catchment characteristics such as vegetation and mean annual discharge needed to estimate DDD model parameters. Derived terrain information and catchment boundaries are furthermore used to extract meteorological information from gridded (1 x 1 km) maps for both historical and forecast periods. The historical period may be of such length (>30 years, daily resolution) that the mean annual flood can be reasonably estimated and compared to forecasted runoff values for hazard assessments. In this way a flood forecaster is no longer limited to only be looking at hydrological simulation results from calibrated models set up for a few gauged catchments. Rather, she can set up a model for ungauged catchments where the forecasted precipitation is the most intense or where vulnerable infrastructure is located. The relative comparison between simulated forecasted runoff and simulated mean annual flood is of value for hazard assessments. Regarding absolute values, the DDD model has been tested for prediction in ungauged basins for 25 gauged catchments and obtains an average Kling-Gupta efficiency (KGE) of 0.77. The mean annual flood is, however underestimated by 40 %. Better results are expected when improved gridded meteorology and estimates of mean annual discharge are available. Future developments include higher temporal and spatial resolutions so that flood forecasting and flood estimation can be carried out for smaller and faster responding ungauged catchments.
Using Opportunistic Rainfall Sensing to improve Areal Precipitation Estimates and Run-off Modelling – The Case Study of the Ahr Flood in July 202
Authors: Seidel Jochen , Bárdossy András , Eisele Micha , El Hachem Abbas , Chwala Christian , Graf Maximilian , Kunstmann Harald , Demuth Norbert , Gerlach Nicole
Published: February 2023

On 14 and 15 July 2021, heavy and prolonged precipitation caused flooding in large areas in western Germany and adjacent regions. The Ahr River valley in the Federal State of Rhineland-Palatinate was particularly affected, with numerous fatalities and large-scale damage. Due to the spatio-temporal variability of precipitation and failure of several gauging stations, the estimation of the flood triggering areal precipitation as well as determination of peak discharges is associated with high uncertainties.In this study, we present results where data from opportunistic sensors (commercial microwave links (CML) and personal weather stations (PWS)) were used to interpolate hourly precipitation sums for the Ahr catchment. The data from the opportunistic sensors was quality controlled, filtered and interpolated using the methods from Graf et al. (2021). This precipitation data was compared to a gauge adjusted weather radar product from the German Weather Service DWD as well as interpolated rain gauge data. In order to determine the maximum discharges at the gauges in the Ahr, flood was simulated with the water balance model LARSIM (Large Area Runoff Simulation Model) using the aforementioned precipitation products as input data.The results show that the areal precipitation obtained from opportunistic sensors yielded higher sums than the gauge adjusted radar products and the interpolated gauge data, especially in the northern part of the Ahr catchment where the station density of the conventional rain gauges was not sufficient to capture the spatial variability of this extreme event. Furthermore, the modelled run-offs using the precipitation input from opportunistic sensors yielded higher and more plausible peak discharges than the ones with the gauge adjusted weather radar product. This suggests that the radar underestimated precipitation due to attenuation. The difference in the resulting peak discharges point to the fact that due to the saturated soils any additional precipitation during the flood event in July 2021 lead to a direct run-off effect. References:Graf, M., El Hachem, A., Eisele, M., Seidel, J., Chwala, C., Kunstmann, H., & Bárdossy, A. (2021). Rainfall estimates from opportunistic sensors in Germany across spatio-temporal scales. Journal of Hydrology: Regional Studies, 37, 100883.
Plume driven plate tectonics: new insights from the Australia/Antarctica separation
Authors: Stotz Ingo L. , Carena Sara , Vílacis Berta , Bunge Hans-Peter , Hayek Jorge N.
Published: February 2023

It is well accepted that convection in the Earth’s mantle provides the torques to drive vertical and horizontal plate motions. Yet the precise nature of the interaction between flow and plates remains incomplete, because the strength of plates allows them to integrate over a presumably complex flow field in the mantle beneath – making it difficult to get a glimpse even on the recent Cenozoic mantle flow. Over the past years a pressure driven, so-called Poiseuille, flow model for upper mantle flux in the asthenosphere has gained increasing geodynamic attention – for a number of fluid dynamic arguments. This elegantly simple model makes a powerful testable prediction: Poiseuille flow induce plate motion changes should coincide with regional scale mantle convection induced elevation changes.Here I will focus on Australia, which undergoes a profound directional change from westward to northward motion in the early Cenozoic. At the same time there is evidence for early Cenozoic high dynamic topography in the western part of the continent. Thus, suggesting a high-pressure source in the upper mantle to the west of Australia. Altogether these geological and geophysical observations indicate that the separation of Australia from Antarctica was largely driven by plume push torque from the Kerguelen plume.
Sensitivity of boundary layer parameterization to the critical bulk Richardson number in a climate model over India and its adjoining regions
Authors: Namdev Prabhakar , Sharan Maithili , Mishra Saroj Kanta
Published: February 2023

The planetary boundary layer (PBL) scheme is required in almost all numerical weather prediction and general circulation models to parameterize the vertical diffusion of mass, moisture and momentum, in which the critical bulk Richardson number (Ricr) is a crucial component. This study investigates the sensitivity of the Holtslag and Boville (HB) PBL scheme to the Ricr in the National Centre for Atmospheric Research Community Atmosphere Model version 5 (NCAR-CAM5) over India and its adjoining regions. According to the HB PBL scheme, turbulent motion in the PBL is caused by surface heating because of incoming solar radiation. The simulations were conducted using various values of Ricr (0.19, 0.25, 0.35, and 0.5) as well as the default scheme (Ricr = 0.30) at a horizontal resolution of 1o. A total of five sets of simulations have been conducted, each for six years; the first year was discarded as spin-up time, and the last five years of simulations are considered for the analysis. The study spans DJF (December–January), MAM (March–May), JJA (June–August), and SON (September–November) seasons over the study domain. The study shows that the HB PBL is highly sensitive to the value of Ricr employed in the simulation. The results demonstrate that over the whole study domain (20S-40N, 40E-140E), as well as just over land and ocean, the mean planetary boundary layer height (PBLH) increases nearly linearly with increasing Ricr during all four seasons. The surface sensible and latent heat fluxes exhibit opposite behaviour towards the increment in the values of Ricr. The 2-m temperature, wind, and specific humidity changes are marginal and insignificant during all seasons. Moreover, the total precipitation averaged over the whole domain also shows increasing behaviour as Ricr increases during all four seasons.Keywords: PBL parameterization, Critical bulk Richardson number, Climate model, Surface turbulent fluxes, Precipitation
The impact of changing freeze-thaw dynamics under recent climatic changes on nutrient leaching in a Swedish agricultural field
Authors: Lackner Anna , Klöffel Tobias , Barron Jennie
Published: February 2023

Agriculture can be a significant contributor of nutrients, such as phosphorus (P) and nitrogen (N) to surface water, increasing the risk of eutrophication. Soil frost and freeze-thaw (FT) cycles impact both the transport of nutrients through changes in the hydrologic regime of the field and the mobility/availability of nutrients through changes in the biogeochemistry of the field.  With a changing climate, changes in the frequency and duration of FT cycles are expected in regions of higher latitudes and altitudes. However, there is a knowledge gap related to the response of nutrient leaching with changing FT patterns in a changing climate.The aim of this study was to investigate the impact of soil freezing and thawing on nutrient leaching (N, P) from an agricultural field in northern Sweden for the period 1989-2021. The FT dynamics were modelled in terms of a soil temperature profile using an explicit soil moisture and energy-based process model – the COUP, at an hourly time step. Long term environmental monitoring data of surface and drainage runoff, combined with soil temperature and soil moisture data were used for model calibration and validation. Finally, the modelled FT dynamics and measured nutrient concentrations and runoff were statistically related to each other.Our preliminary findings confirm the importance of soil frost occurrence for the separation of surface runoff and drainage. However, no clear relationship between soil FT dynamics and nutrient loads (or concentrations) in surface or drainage water could be observed. This suggests that changes in the hydrological regime through freezing and thawing are most important for the amount and export pathways of nitrogen and phosphorous as compared to alternative mechanisms of nutrient mobilisation.
New formulation of the olivine thermobarometer for mantle xenoliths
Authors: Ashchepkov Igor
Published: February 2023

The suggested olivin thermometry for mantle peridotite and zenolith (Hoog et al., 2010, Bussweller et al., 2017) allow correct estimation of the temperatures using high precision data obtained by LA ICP MA or even EPMA inn hjigh resolution. IN this version we tried to obtain the pressure eestimates using the inversion of the Ol thermometer to barometer. And also we substituted the CaO by MnO withe essential correction. In this variant  I received the pair of the Ol thermometer and Mn - in - olivine barometer which allow to work not only with the high resolution data but with the routine analyses and obtain not bad estimates for the see of data for the Udachnaya, Zarnotsa, Aykhal and other pipes (Ashchepkov et al., 2010-2021) and even fo the diamond inclusions (Ashchepkov et al., 2021-2023). RBRF grant 19-05-007888
Numerical modeling and time series analysis to quantify the neglected groundwater component in Lake Velence’s water budget – a case study from Hungary
Authors: Baják Petra , Hegedűs-Csondor Katalin , Csepregi András , Chappon Máté , Bene Katalin , Erőss Anita
Published: February 2023

Lake Velence is a shallow soda lake in Hungary, which has a diverse ecosystem and is a popular tourist destination. Because of that, the lake is the focus of continuous interest and is constantly examined in terms of water quality and quantity. In recent years, it has been observed that the lake's water and nutrient budget is negatively affected by climate change. Since the very existence of the lake is threatened, it has become important to assess the quantity of water flowing into and out of the lake. In our research, the emphasis is on the investigation of the groundwater component, since groundwater can represent a significant buffer in the lake's water balance against climate change, and since in water management practice, neither inflow nor outflow of groundwater is currently considered in the lake’s water budget. Therefore, we wanted to understand the nature of the relationship between the lake and the groundwater and quantify the amount of inflowing and outflowing groundwater.To achieve our aim, we created a regional-scale transient 3D numerical groundwater flow model for the lake's catchment area using Visual MODFLOW. The time series of weather parameters (i. e. amount of precipitation, evaporation, temperature), the discharge rate of surface water courses, and groundwater extraction data from 1990-2020 have been incorporated into the model. To calibrate the model, we used the time series of monitoring wells of unconfined and confined aquifers. The mentioned time series were also analyzed using statistical methods such as the relationship between rainfall, the groundwater level measured in wells, and the lake level.Our results complemented the previous studies on the lake's catchment area: there is a not insignificant connection between the lake and groundwater, and the lake is fed by local flow systems with shallow penetration depth and relatively short residence time, which are known to be more sensitive to climate change. Finally, we used the calibrated model to test different scenarios, e. g. we have reduced rainfall or increased water withdrawals to highlight the lake's vulnerability to future changes.The research was supported by the ÚNKP-22-3 New National Excellence Program of the Ministry for Culture and Innovation from the source of the National Research, Development and Innovation Fund. Part of the research was funded by the National Multidisciplinary Laboratory for Climate Change, RRF-2.3.1-21-2022-00014 project.
Structural-, in-situ permeability- and K-Ar geochronological constraints from complex and heterogeneous fault zones: new perspectives on fluid circulation and seismogenesis in the upper crust
Authors: Viola Giulio , Curzi Manuel , Giuntoli Francesco , Vignaroli Gianluca
Published: February 2023

Long-lived, mature faults can be architecturally complex. The in-depth unravelling of their complexity, including understanding the dynamic and multiscalar evolution of their mechanical properties, requires detailed multidisciplinary studies. Indeed, an integrated approach is the only viable solution to the deconvolution of the at times very complex internal architecture of brittle fault zones, which represents a phenomenal archive of faulting history and conditions through time and in space. Fault zone architectures are commonly characterized by the spatial juxtaposition of “brittle structural facies” (BSFs), which progressively form and continuously evolve during faulting. The mutual spatial and temporal relationships of BSFs impact directly on the bulk static and dynamic permeability structure of fault zones. The permeability structure, in turn, plays a significant role on the distribution of georesources and on seismogenesis in the brittle upper crust, where both natural and induced seismicity are often associated with fluid migration and overpressure. Detailed models of the complexity of fault zones and of their static and dynamic permeability structure are thus necessary to refine our understanding of fluid pathways and of the mechanisms leading to fluid compartmentalization and possible overpressure in the crust. We present a multidisciplinary workflow to decipher exhumed complex fault zones by integrating detailed structural analyses with geochronological dating of the deformation events recorded by the constituent BSFs and systematic in-situ permeability measurements to connect deformation structures to deformation age and hydraulic properties. The absolute dating of BSFs constrains how fault hydraulic properties change not only through space but also in time (during seismic or orogenic cycles, for example) as the fault architecture (and permeability structure) progressively develop. As a case study, we apply this workflow to the Zuccale Fault in the northern Apennines (Italy), a major low-angle fault that formed and was repeatedly reactivated during a time interval spanning at least the last 22 Myr. A stark spatial heterogeneity of its present-day permeability (up to four orders of magnitude) emerges as a key structural and hydraulic feature, even for tightly juxtaposed BSFs. Results show how complex fault architectures steer the 3D hydraulic structure of the brittle upper crust with direct implications on styles and modes of fluid ingress and flow.
AdriaArray Seismic Network – status in April 2023
Authors: Kolínský Petr , Meier Thomas , Seismology Group the AdriaArray
Published: February 2023

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 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 990 permanent broad-band stations are operated by more than 40 institutions. Data of 97% of these stations are currently available via EIDA. In addition to the existing stations, 414 temporary stations from 24 mobile pools are deployed in the region achieving a coverage with an average station distance of 50 – 55 km. The experiment is based on intense cooperation between local network operators, mobile pool operators, field teams, ORFEUS, and interested research groups. Altogether, more than 50 institutions are participating in the AdriaArray experiment. We will report on the time schedule, participating institutions, mobile station pools, maps of 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.
Impact of climate change on groundwater level dynamics and karst spring discharge of several karst systems in the Mediterranean area
Authors: Cinkus Guillaume , Sivelle Vianney , Jourde Hervé , Mazzilli Naomi , Tramblay Yves , Andreo Bartolomé , Barberá Juan Antonio , Bouhlila Rachida , Doummar Joanna , Fernández-Ortega Jaime , Gargouri-Ellouze Emna , Lorenzi Valeria , Petitta Marco , Ravbar Nataša , Slama Fairouz , Goldscheider Nico
Published: February 2023

Anthropogenic activities and climate change exert significant pressures on the quality and availability of water resources in karst environments, which supply drinking water to about 9.2% of the world's population. Increasing temperatures and changes in precipitation regimes will strongly impact water recharge processes. Understanding the karst hydrodynamic behaviour in the present context of climate change constitutes a major challenge for a sustainable management of karst groundwater. This study focuses on the Mediterranean area, where up to 90% of the drinking water supply depends on carbonate aquifers. The spring discharge and/or water level of six karst systems in the Mediterranean area (France, Italy, Lebanon, Slovenia, Spain and Tunisia) are simulated using precipitation-discharge reservoir modelling tools. The studied karst systems are well known and have different characteristics in terms of climatic conditions, hydrogeological properties and available data. Using different model structures, the hydrological models are first calibrated and validated over a historical period and then used to simulate spring discharge time series under various climate projections (up to 2100). To account for uncertainties in climate projection, 12 coupled GCM/RCM climate models are considered with two emission scenarios (RCP 4.5 and RCP 8.5) proposed in the framework of the CMIP5 initiative. The analysis of the forecasted spring discharge and water level time series focuses on (i) the long-term trends in the hydrological functioning of karst systems, (ii) the effects of climate change on spring discharges (intensity and duration of extreme events), and (iii) the study of uncertainties related to the exceedance of the known functioning ranges of the systems. Further discussion is also dedicated to model uncertainties in relation to model parameters and structure, climate models, and the estimation of potential evapotranspiration in future climate. This research has been conducted within the KARMA (Karst Aquifer Resources availability and quality in the Mediterranean Area) project into the PRIMA (Partnership for Research and Innovation in the Mediterranean Area) EU program.
Decreasing trends of NH3 over Europe seen from space
Authors: Evangeliou Nikolaos , Tichy Ondrej , Eckhardt Sabine , Balkanski Yves , Hauglustaine Didier
Published: February 2023

Ammonia (NH3), the only basic gas in the atmosphere, constitutes one of the most reactive nitrogen species. It mainly originates from agricultural-related activities, with emissions contributing over 80% globally, while locally they can reach as high as 94%. Once it is emitted, it is transported and deposited to water bodies, soil or vegetation and can then lead to eutrophication of water bodies, modulate soil pH and burn vegetation. It also reacts in the atmosphere with the abundant sulfuric and nitric acids forming fine particulate matter (PM2.5), which affect Earth’s radiative balance, causes visibility problems, but also affects human health, as it penetrates the human respiratory system. However, despite its significance, ammonia source emissions are poorly constrained due to lack of ground-based measurement. Today, several satellite products have become available mainly from satellite sounders. In the present study, we use direct comparisons between the CrIS (Cross-track Infrared Sounder ) observations and model retrievals using the Least Squares with Adaptive Prior Covariance (LS-APC) algorithm, which reduces the number of tuning parameters in the method significantly using variational Bayes approximation technique. We constrain ammonia emissions over Europe over 2013–2020 and validate the results against ground-based observations from the EMEP (European Monitoring and Evaluation Programme). We find that emissions of ammonia decreased from 5431 Gg in 2013 to 3994 Gg in 2020 (-26%). Regionally, emissions declined by 38% in Central and Eastern Europe, 37% in Western Europe, 8% in Southern Europe and -17% in Northern Europe.
The effect of thermal non-equilibrium on aerosol formation in astrophysical environments
Authors: Kiefer Sven , Gobrecht David , Decin Leen , Helling Christiane
Published: February 2023

From our Solar System, we know that gas giant planets are covered in clouds and we expect the same to hold true for many exoplanet gas giants. Knowing the composition and size of cloud particles and where they form within exoplanet atmospheres is crucial to understand exoplanet observations. The first step in cloud formation is the nucleation of aerosols. These nano-sized particles function as seeds for condensation processes through which cloud particles grow. The nucleation and condensation processes are highly temperature dependent. The day side of ultra-hot Jupiters are expected to be cloudless whereas their night side and colder gas giants are expected to be covered in clouds. Recent observations and studies of stellar outflows have shown that thermal non-equilibrium can be present in low density environments and that thermal non-equilibrium can have a significant impact on the formation of larger clusters. In this study, we investigate the effect of thermal non-equilibrium on the formation of aerosols. We derive a kinetic homogeneous cluster nucleation model for non-uniform cluster temperatures. We use this model to study the nucleation of titania (TiO2) which is considered to be an important condensate in exoplanet atmospheres. We analyse the impact of thermal non-equilibrium on the number densities of (TiO2)N, N=1-10, clusters. We find that small temperature offsets between different cluster sizes can have a significant impact on the formation of aerosols. Therefore, studies of low density environments should consider the effects of thermal non-equilibrium on nucleation. In collision dominated regimes, clusters are efficiently driven towards thermal equilibrium and thermal non-equilibria are unlikely to occur.
Onshore-offshore relationship and anatomy of a necking zone: insights from high-resolution aeromagnetic survey on the Finnmark Platform (Norwegian Barents Sea)
Authors: Gernigon Laurent , Haase Claudia , Gradmann Sofie , Dumais Marie-Andrée , Slagstad Trond , Ofstad Frode , Nasuti Aziz , Bronner Marco
Published: February 2023

We integrated high-resolution aeromagnetic data and 2D/3D seismic data from the Norwegian Southwestern Barents Sea. The main objective is to address the long-standing question on the role of pre-existing basement structures in controlling strain accommodation and extension in the Finnmark Platform and adjacent rift basins. The thorough qualitative analysis of the high-resolution magnetic data reveals fault geometries, regional kinematics, magmatism and inheritance of older Precambrian/Caledonian structures. Through the application of second order derivative filters and depth-to-magnetic-source modelling, the trends of the Caledonian metamorphic fabrics are identified and correlated with the structure of buried basement faults and shear zones also imaged at the same level of resolution on 2D/3D seismic data. The magnetic data reveal an unprecedented detail of the basement fabrics dominated by high-frequency NW-SE trending magnetic lineaments associated with the semi-regional Sørøya-Ingøya Shear Zone. The high-frequency magnetic lineaments are superimposed by lower frequency NNW-SSE trending magnetic lineaments that reflect the inheritance of older Precambrian structures. At the edge of the Tromsø Basin, the new magnetic data highlight sill intrusions also visible on seismic data. Fault geometries, regional kinematics, and spatial distribution of the magnetic sources suggest that old detachments and younger Mesozoic faults reactivated the basement fabrics found along the graben borders. Focusing of strain accommodation at the edge of the Hammerfest Basin is helped as well as modulated by the presence of back-thrusted Caledonian nappes interpreted on the Finnmark Platform. Offshore, surface ruptures associated with graben formation align with the dominant NNW-SSE trending magnetic lineaments defining steeper normal faults that are characterised by right-stepping segments along the southern flank of the Hammerfest Basin. Based on potential field models, we finally quantify the crustal architecture of the rift and platform system. At upper crustal level, we test the presence and significance of potential Palaeozoic basin preserved at the edge of the basement hinge-zones. Potential field modelling also highlights and quantifies several rift domains defined by moderate to extreme thinning of the crust (low-β stretched domain, necking, and high-β hyperextended regions). The development of the necking zone is clearly influenced by the existence of former first-order and multi-scale inherited basement features preserved in the Finnmark Platform.
Warming may cause substantial nitrogen losses from subarctic grasslands
Authors: Marañón Jiménez Sara , Luo Xi , Richter Andreas , Gündler Phillipp , Fuchslueger Lucia , Sigurdsson Bjarni D. , Janssens Ivan , Peñuelas Josep
Published: February 2023

High-latitude soils are particularly vulnerable to temperature-driven C losses and may contribute substantially to the increasing atmospheric CO2 concentrations. The magnitude of their contribution is, however, uncertain, and largely dependent on the interactions between C and nitrogen (N) biogeochemical cycles, soil microbial activities and the feedbacks between plants and soil microbes. Warming may cause a particularly pronounced acceleration of soil N transformation in N-poor cold regions. The consequent alleviation of plant N limitations in cold ecosystems may increase plant productivity and C inputs to the soil, compensating the expected soil C loss, at least partially. Alternatively, warming may desynchronize or unbalance the intimate coupling between microbial N mineralization and vegetation N uptake, leading to potential soil N loss, but also higher soil C losses. We aimed to elucidate potential mechanisms of ecosystem N losses in subarctic grasslands by determining the effects of soil warming on the seasonal patterns of plant N acquisition and microbial net N immobilization. For this, we performed a seasonal isotope tracing experiment using a mix of 15N-labelled amino-acids along soil temperature gradients in geothermal systems in Iceland.Soil microbial biomass acted as a temporal reservoir of N by increasing N immobilization particularly during unfavorable winter periods for vegetation, likely due to the alleviated microbial C limitation. However, soil warming exacerbated microbial C limitation and decreased the N storage capacity of soil microbes during snowmelt periods. As a result, a higher proportion of N remained in the extractable soil fraction susceptible to leaching losses.  , however, this increased plant N uptake did not compensate for the lower microbial biomass N storage, leading to ecosystem N losses. Our results highlight the relevant role of soil microbes to safely store and immobilize N when plants do not need it and to release N when plants require it. Warming can weaken this particularly important soil microbial function in cold regions, leading to substantial ecosystem N and fertility losses, which may also promote irreversible soil C losses in these ecosystems.
First applications of the Virga-Sniffer – a new tool to identify precipitation evaporation using ground-based remote-sensing observations
Authors: Kalesse-Los Heike , Kötsche Anton , Foth Andreas , Röttenbacher Johannes , Vogl Teresa , Witthuhn Jonas
Published: February 2023

The dominant cloud type in the subtropical Atlantic is the trade wind cumulus with a cloud base located near the lifting condensation level (LCL) below 1 km. Other common clouds in this region with their base above 1 km are stratiform cloud layers or cloud edges near the trade wind inversion at 2-3 km. Precipitation in all these clouds mainly forms at temperatures above freezing point by collision and coalescence. Therefore, precipitation generally occurs as light rain/drizzle from stratiform cloud layers or as showers from well-developed trade wind cumuli. Precipitation underneath a cloud base is often visible as fall streaks. If the precipitation evaporates before reaching the ground, these fall streaks are called virga.Combined continuous long-term ground-based remote-sensing observations with vertically pointing cloud radar and ceilometer are well-suited to identify these precipitation evaporation fall streaks. Here we show the first application of a new open-source tool, the Virga-Sniffer which was developed within the frame of RV Meteor observations during the ElUcidating the RolE of Cloud–Circulation Coupling in ClimAte (EUREC4A) field experiment in Jan–Feb 2020 in the Tropical Western Atlantic. In the simplest approach, it detects virga from time-height fields of cloud radar reflectivity and time series of ceilometer cloud base height. The Virga Sniffer was applied to RV Meteor observations during EUREC4A and statistical results as well as an evaporation case study are presented. Spectral W-band radar data from a fall streak, identified as virga by the Virga-Sniffer, was used to calculate evaporative cooling rates. Sensitivity studies were performed to investigate the influence of vertical wind and relative humidity uncertainties.  Possible future applications of the Virga-Sniffer within the frame of EUREC4A include detailed studies of precipitation evaporation with a focus on cold pools or cloud organization, or distinguishing moist processes based on water vapor isotopic observations.
Geothermal Energy in Switzerland: roadmap to 205
Authors: Lupi Matteo
Published: February 2023

For decades, geothermal energy was harnessed from magmatic systems only. This is no longer the case since projects began to exploit the energetic potential of a variety of geological domains across different tectonic settings. Vertical ground heat exchangers, groundwater aquifers and enhanced geothermal systems are only a few of a large spectrum of solutions proposed to harvest geothermal energy practically anywhere.Despite lacking high-enthalpy geothermal resources, Switzerland is today one of the leading countries for research and development in the geothermal sector. New projects have been launched, underground laboratories have been developed and a wealth of research opportunities are rising. The new challenges to be faced are supported by solid research schemes fostering interaction between research and industrial partners. I will provide a brief overview of Switzerland’s geothermal roadmap to 2050 describing how the Helvetic confederation is planning to attend about 2 TWh of energy (and about 18 TWh if heat is also considered) by 2050. I will highlight the collaborative research opportunities and the future challenges that our community will have to undertake to foster geothermal energy as a solid and reliable resource to fuel our society across the energetic transition.
Integration between space- and ground-based observations in areas prone to volcanic hazard: the experience of Mt. Etna Supersite
Authors: Puglisi Giuseppe , Bonforte Alessandro , Buongiorno Maria Fabriza , Cacciola Lucia , Guglielmino Francesco , Ganci Gaetana , Musacchio Massimo , Scollo Simona , Reitano Danilo , Silvestri Malvina , Spampinato Letizia
Published: February 2023

The Geohazard Supersites and Natural Laboratories (GSNL) is an initiative of the Group of Earth Observation (GEO) that has started in 2007 with the Frascati declaration, in which the GeoHazards Community of Practice recommended to: “... stimulate international and intergovernmental effort to monitor and study selected reference (geologic hazards) sites, by establishing open access to relevant datasets according to GEO principles, to foster collaboration between various partners and end users”. Since the beginning the main idea has been the improvement of the hazard assessment by combining space- and ground-based datasets provided by the Space Agencies and the research institutions managing the in-situ observation systems, respectively.According to the definition of Supersite, since the early stage of the GSLN initiative, Mt. Etna has been identified as one of the Supersites due to its almost continuous eruptive activity, the great amount of satellite and in-situ data available, and the advanced in-situ multi-parametric observing systems. Officially, Mt. Etna is a Permanent Supersite since 2014. The Space Agencies provide quotas of SAR and high-spatial resolution optical multispectral satellite data and INGV offers geophysical, geochemical, and volcanological data. The data are accessible via an open access platform implemented in the framework of the EC FP7 MED-SUV project, and is going to be integrated in the EPOS research infrastructure.During the past few decades, Mt. Etna has erupted almost every year offering the optimal conditions to apply the Supersite concept; thus here we report some relevant examples of the integrated use of the space-and ground-based data applied to Mt. Etna’s eruptions, highlighting how such complementarity improved the monitoring of the eruptive events and the assessment of the associated hazards.
Applying space-time activity data and socio-economic profiles to assess the variation of personal air pollution exposures
Authors: Schmitz Oliver , de Hoogh Kees , Probst-Hensch Nicole , Jeong Ayoung , Flückiger Benjamin , Vienneau Danielle , Hoek Gerard , Kyriakou Kalliopi , Vermeulen Roel C. H. , Karssenberg Derek
Published: February 2023

Long-term personal air pollution exposures estimates from nationwide cohorts are useful in studies of the relationship between air pollution exposure and chronic diseases such as diabetes or cardiovascular disease. Ignoring space-time activity patterns and neglecting mobility in exposure assessment may lead to incorrect exposure distributions and bias in downstream exposure health relations. In our study we estimate personal air pollution exposures nationwide and across socio-economic and age profiles to identify the relevance of location or profiles on exposure analysis.We developed a set of characteristic diurnal activity profiles that we use to calculate exposures for each home address in Switzerland. The profiles are specified by different characteristics such as age group, social economic status, or commute type (e.g. by car, bicycle, on foot). Potential working locations are retrieved from origin-destination matrices for a particular profile, derived from the annual Structural Survey data from the Swiss Population Census (https://www.bfs.admin.ch/bfs/en/home/statistics/population/surveys/se.html), at the level of municipalities. Commute trips between residential and work location are then calculated using the shortest route on OpenStreetMap data. For each profile and each residential address, we run an agent-based model in Monte Carlo mode, generating a database of personal long-term exposures to NO2 and PM2.5 for further epidemiological analysis.Our activity-based mobility simulation provides a representative description of space-time activities of individuals. We present the model results at all unique 1.8 million residential address locations in Switzerland. We compare the exposure assigned from residential address alone to the exposures derived from 20 different activity profiles and present the differences between profiles. We also demonstrate the spatial variability of exposures per profile and the associated uncertainty.The generated exposure database can be used for epidemiological analysis of large-scale cohorts, and enables follow-up studies to evaluate whether including commuting and other activities and therefore more detailed estimates of individual exposure results in more accurate risk estimates in health studies.
Centennial scale reconstruction of metal pollution in Europe's largest saltwater lagoon.
Authors: Alorda-Montiel Irene , Rodellas Valentí , Arias-Ortiz Ariane , Rodríguez-Puig Júlia , Alorda-Kleinglass Aaron , Green-Ruiz Carlos R. , Diego-Feliu Marc , Masqué Pere , Gilabert Javier , Garcia-Orellana Jordi
Published: February 2023

The Mar Menor coastal lagoon (Spain) is a critical ecological and socioeconomic ecosystem and the first in Europe to be granted rights of personhood. However, pollution from past and present activities such as mining, agriculture, urbanization, and tourism threatens its health and ecological stability. Previous research has shown the importance of metal contamination in the lagoon and its link to nearby mining activities, but little consideration has been given to historical changes in this industry and in other potential metal sources. In this work, metal concentrations have been analyzed in 12 sediment cores dated with 210Pb, allowing the reconstruction of the recent (last ~150 years) metal contamination in the lagoon. The main metal sources have been identified by using multivariate statistical methods. Metal contamination from mining activities (point-source pollution) peaked in the mid-20th century, whereas nonpoint-source metal contamination reached its highest level in more recent decades. Despite the current decrease in metal deposition trends, concentrations in surface sediments still exceed sediment quality and ecotoxicological thresholds in areas close to former mining sites. Therefore, they need to be considered in future management strategies, which should also include the evaluation of sources and processes that are still supplying them to the lagoon. 
On the reliability of bivariate forecasts
Authors: Ben Bouallegue Zied
Published: February 2023

Reliability is a key attribute of an ensemble forecast. Typically, this means that one expects that the ensemble spread reflects the potential error of the corresponding ensemble mean forecast. In the realistic case of an unperfect forecast, reliability deficiencies can be diagnosed with tools such as the reliability diagram and the rank histogram. Along with the computation of scores, the use of these diagnostic tools is common practice in ensemble forecast verification when assessing univariate forecasts. But what does reliability mean in practical terms when assessing multivariate forecasts? Here the concept of reliability is revisited in the simplest of the multivariate cases: the bivariate forecast. As a result, we propose a set of new diagnostic tools with an emphasis on the cross-variable reliability aspect. Real case examples are used for illustration and discussion.