bluuebunny/crossref_metadata_2025 huggingface dataset:
The diurnal cycle of precipitation over the Maritime Continent: characterisation in observations and models
Authors: Mustafa Jack , Matthews Adrian , Hall Rob , Heywood Karen , Azaneu Marina
Published: February 2023

The meteorological diurnal cycle over the Maritime Continent is a major component of observed variability and features see-sawing of intense precipitation from over land through the afternoon and evening to over surrounding seas and oceans through the night into the morning. This high-frequency land-locked mode of variability interacts with lower-frequency propagating modes of tropical variability, such as the Madden-Julian Oscillation, therefore accurate forecasting of downstream impacts of these intraseasonal modes of variability depends on accurate understanding and model representation of the diurnal cycle.In this presentation we compare the observed diurnal cycle of precipitation with the diurnal cycle generated by regional hindcast runs of the UK Met Office Unified Model with parameterised and with explicitly-resolved convection. A novel characterisation framework is used to quantify the cycle at each location in order to optimise the intuitive simplicity and the completeness of the characterisation.
Impact of 3D non-hydrostatic dynamics on tracer transport in the nearshore region
Authors: Treillou Simon , Marchesiello Patrick
Published: February 2023

The nearshore zone, including the surf zone and the inner shelf (up to about 20 m depth), is a particularly chaotic zone where processes with very different scales coexist and interact permanently. This very active region, which marks the transition from the continent to the sea, is of crucial importance in many aspects (beach erosion/accretion, dispersion of pollutants or larvae, users’ safety, etc.). Several studies have already looked at the transport of passive tracers in the nearshore zone, but they generally use depth-averaged models. As a result, little is known about the non-hydrostatic 3D processes governing the nearshore zone, while depth-averaged models struggle to accurately represent measured data. For example, they tend to underestimate transport in the surf zone and overestimate it on the inner shelf. Recently, 3D wave-resolving models with a free surface have been made available to researchers. One of these models, CROCO (Coastal and Regional Ocean Community model) is used here and allows the simulation of nearshore processes with a reduced number of unknown parameters. The model is applied to a large-scale dye release experiment in California (Imperial Beach, 2009), for which simulations with the depth-averaged funwaveC model have already been performed. The IB09 survey is ideal to study processes as the beach is almost alongshore uniform. Several diagnostics are performed, such as tracer mass balance or quantification of the exchange between the surf zone and the inner shelf. The diagnostics highlight the vertical shear and 3D instabilities at work in the nearshore zone and infer the ability of 3D wave-resolving models to adequately reproduce the available observations, particularly with respect to surf-shelf exchange. This work may in the future suggest feedback for better parameterization in coarser, simpler models for a more accurate depiction of coastal pollution fate and sediment transport.
Linkage between overturning and density anomaly over the subpolar gyre
Authors: Petit Tillys , Robson Jon , Ferreira David , Evans D. Gwyn
Published: February 2023

The surface forced water mass transformation (SFWMT) is known to be the main contributor of the Atlantic Meridional Overturning Circulation (AMOC) over the subpolar gyre. Over the eastern part of the subpolar gyre, a recent study revealed the dominant role of surface density changes in driving the SFWMT as opposed to the direct influence of air-sea fluxes. Indeed, the distribution at surface of the isopycnal associated with the maximum overturning streamfunction, Smoc, modulates the area of dense water formation induced by the air-sea fluxes.The Overturning in the Subpolar North Atlantic Program (OSNAP) showed that the density of Smoc is highly variable in time along each section of the array. However, the drivers of Smoc remain unclear. In our work, we use a combination of atmospheric reanalysis and coupled simulations of HadGEM3-GC3.1 to evaluate the Smoc variability over the subpolar gyre as well as its connection with the overturning strength. At interannual timescale, the variability of Smoc at OSNAP East is strongly related to those at OSNAP West and at 45°N. However, its connection with the overturning strength is more complex. Although Smoc is not well related to the overturning at OSNAP, it is associated with a shift in density of the overturning stream function. The Irminger Sea is identified as being the centre of action driving this variability.
Measuring and Modelling Evapotranspiration over Complex Terrain
Authors: Hartogensis Oscar , Mangan Mary Rose , Aguirre Correa Francisca , Lobos Roco Felipe , Stoffer Robin , Vilà-Guerau de Arellano Jordi
Published: February 2023

This contribution deals with the spatial and temporal scales involved in the processes that control evapotranspiration (ET) and confront these with the merits and limitations of various observation and modelling techniques. We make a strong case for integrated approaches to further develop our understanding of evapotranspiration.The most challenging, but at the same time most relevant conditions to accurately represent ET are found in semi-arid regions, specifically complex terrains with strong thermal contrasts between dry and wet (irrigated) areas. We will present three cases with different objectives in terms of processes that control ET and the methods used to study them. First is the LIAISE campaign, where we will focus on how to describe ET depending on the spatial scale considered ranging from regional to landscape to local scale. Second is the E-DATA campaign, where ET is controlled by a thermally driven and topographically enhanced regional flow that alters the turbulent mixing and the structure of the atmospheric boundary layer. Third deals with a machine learning approach to determine ET based on standard weather station data.LIAISE took place during the summer of 2021 in the Pla d’Urgell region of the Ebro River Valley in Catalonia, Spain. The surface was homogeneous at the field scale (e.g. fields of alfalfa). However, the surface was heterogeneous at the regional scale (~10-100km) because of the spatial distribution of irrigated crops and dry natural vegetation. We examined the impact of the boundary layer on surface fluxes at two of the LIAISE sites: one in the irrigated, crop-covered area and one in the dry, naturally-vegetated area.  We use an atmospheric mixed-layer column model that is heavily constrained by the surface and boundary layer observations from the LIAISE experiment.The E-DATA experiment took place during November 2018 and focussed on quantifying the processes that drive ET in a shallow lake surrounded by extremely dry conditions in a salt flat (Salar del Huasco) of the Chilean Atacama desert. We use the WRF model at 100-m resolution to represent the local processes as well as the heterogeneity and regional transport to understand the evaporation and ABL dynamics over the water.The machine learning study explores whether a physics-informed machine learning  approach can be used to improve the estimated evapotranspiration for irrigated fields located in a desert environment, without arbitrary tuning after training  and only using readily available data (standard meteorological data and satellite derived vegetation indices). We focus on an irrigated pecan orchard in Northwest Mexico. Multi-year eddy-covariance ET estimates are used to train and validate the model.
Dynamics and radiation of thrust earthquakes with coseismic off-fault damage
Authors: Villafuerte Carlos , Okubo Kurama , Rougier Esteban , Madariaga Raul , Bhat Harsha S.
Published: February 2023

Major earthquake ruptures occur predominantly in thrust faults producing devastating events and tsunamis such as the 2011 Mw 9.0 Tohoku earthquake, the 2004 Mw 9.2 Sumatra earthquake and the 1999 Mw 7.7 Chi-Chi earthquake. Understanding the mechanics of earthquakes in thrust faults and the effect of the free surface is thus crucial to explain their large shallow slip, their asymmetric ground motion and their damage patterns surrounding the fault and the free surface. In this work, we carry out 2D dynamic rupture simulations on thrust faults to accurately characterize a possible unclamping effect, its responsible physical mechanism, and to produce dynamically activated off-fault fracture networks. To conduct the simulations, we use the software tool based on the Combined Finite-Discrete Element Method (FDEM), HOSSedu, developed by Los Alamos National Laboratory. Our dynamic rupture models in an elastic medium confirm that unclamping occurs in thrust faults and increases significantly as the rupture reaches the free surface and for the fault models with lower dip-angles. We show that this is a consequence of the torque mechanism induced in the hanging wall, and the release of this torque when the rupture reaches the free surface produces a “flapping” in the toe of the wedge where the most significant unclamping (possibly leading to fault opening) is taking place. Our results indicate that the free surface produces a considerable reduction of the compressive normal stress when the rupture is propagating up-dip that facilitates the extension and the amount of slip close to the trench as observed for large thrust earthquakes.This significant normal stress change is reflected in the orientation of the principal stresses before and after the rupture, where under certain conditions, the greatest principal stress changes from subhorizontal to almost vertical leading to a post-rupture tensional stress state in the hanging wall that has been confirmed by observations of recent in-situ, seismological and geodetic studies. Finally, we investigate whether this dramatic normal stress reduction stands when we allow for the activation of coseismic off-fault damage and explore its role in the rupture dynamics, the near-field deformation and radiation patterns.
Limited Mediterranean sea-level drop during the Messinian salinity crisis inferred from the buried Nile canyon
Authors: Gvirtzman Zohar , Heida Hanneke , Garcia-Castellanos Daniel , Bar Oded , Zucker Elchanan , Enzel Yehouda
Published: February 2023

The extreme Mediterranean sea-level drop during the Messinian salinity crisis has been known for >50 years, but its amplitude and duration remain a challenge. Here we estimate its amplitude by restoring the topography of the Messinian Nile canyon and the vertical position of the Messinian coastline by unloading of post-Messinian sediment and accounting for flexural isostasy and compaction. We estimate the original depth of the geomorphological base level of the Nile River at ~600-m below present sea level, implying a drawdown 2-4 times smaller than previously estimated from the Nile canyon and suggesting that salt precipitated under 1-3-km deep waters. This conclusion is at odds with the nearly-desiccated basin model (>2 km drawdown) dominating the scientific literature for 50 years. Yet, a 600-m drawdown is ca. five times larger than eustatic fluctuations and its impact on the Mediterranean continental margins is incomparable to any glacial sea-level fall.
Hygroscopic and optical properties of complex aerosol mixtures at the Rambouillet forest super-site of the ACROSS project
Authors: Formenti Paola ,   ACROSS/Rambouillet aerosol team
Published: February 2023

The ACROSS (Atmospheric ChemistRy Of the Suburban foreSt) project is an integrative and innovative large-scale initiative that seeks to definitively improve the understanding of the impacts of mixing urban and biogenic air masses in the largest Paris area (the Île-de-France region), where the Paris anthropogenic emissions and the biogenic emissions from the forested surroundings  give rise to the coexistence of several particulate and gaseous species. This scheme promotes the formation of complex mixtures and also influences the physico-chemical aging of aerosol plumes, with consequences on the optical and hygroscopic properties of aerosols, and ultimately on their impacts. Representing the physico-chemical properties, distribution and radiative effect of aerosols at the regional scale of Ile de France is a challenge, limiting our ability to provide reliable climate projections.ACROSS is based on a multiple platform intensive measurement campaign which was held in June-July 2022. In this paper, we present the first results of the ground-based observations of the aerosol hygroscopic and optical properties at the ACROSS supersite within the downwind Rambouillet forest, located on the south-west of Paris. Here, the PEGASUS (PortablE Gaz and Aerosol Sampling UnitS) mobile facility was operated to deploy an HTDMA (humidified tandem differential mobility analyser) to measure the size-resolved aerosol hygroscopic properties, and a suite of optical analysers including a spectral aethalometer (Magee sci model AE33), a spectral nephelometer (TSI Inc model 3596), and three CAPS-type instruments (Aerodyne Inc, models PMEx and SSA) to measure the particle absorption, scattering and extinction coefficients at wavelengths ranging between 370 and 950 nm. The HDTMA was set to operate primarily at 85% relative humidity. . The observational period was characterised by variable conditions ranging from clean to very polluted depending on the weather.  The surface mass concentrations of submicron particles varied between 2 and 15 µg m-3 through the experimental campaign. The aerosol single scattering albedo at 450 nm varied between 0.88 and 1 during the campaign, the lowest values being observed during the heatwave period between 15 and 22 June when the aerosol optical depth reached 0.5 at 440 nm. The size growth factor (GF) for particles of 200 nm varied between 1 and 2 depending on air mass type and time of the day. The observations will be linked to the aerosol chemical composition and aerosol mixing state also observed during the campaign.
Wavelet determination of magnetohydrodynamic range power spectral exponents in solar wind turbulence seen by Parker Solar Probe
Authors: wang Xueyi , Chapman Sandra , Dendy Richard , Hnat Bogdan
Published: February 2023

The high Reynolds number solar wind flow provides a natural laboratory for the study of turbulence in-situ. Parker Solar Probe samples the solar wind between 0.2 AU to 1 AU, providing an opportunity to study how turbulence evolves in the expanding solar wind. We obtain the scaling exponents andscale breaks of wavelet power spectra of magnetic field fluctuations sampled by PSP/FIELDS. We identified multiple, long-duration intervals of uniformsolar wind turbulence, selected to exclude coherent structures such as pressure pulses and current sheets, and in which the primary proton populationvelocity varies by less than 20% of its mean value. All selected events span the spectral scales from the approximately 1/f range at low frequencies, through the magnetohydrodynamic (MHD) inertial range of turbulence and into the kinetic range, below the ion gyrofrequency. We estimate the power spectral density (PSD) using a Haar wavelet decomposition which provides accurate estimates of the exponents. There is a clear transition between Kolmogorov −5/3 and Iroshnikov-Kraichnan −3/2 scaling inwards of 0.5 − 0.6AU. In some cases, we find two ranges of scaling within the inertial range, with scaling exponents that can be discriminated within uncertainties in the wavelet PSD. These correspond to relatively small plasma beta. Since the PSD estimated scaling exponents are a central prediction of turbulence theories, these results provide new insights into our understanding of the evolution of turbulence in the solar wind.  
Swarm A and C Accelerometer - data analysis and scientific outcome
Authors: Iorfida Elisabetta , Daras Ilias , Strømme Anja
Published: February 2023

The ESA Swarm mission was launched in November 2013, and it consists of a constellation of three identical satellites. The main mission objective is to model and analyze the geomagnetic field through the data provided by a vector and a scalar magnetometer on board of each spacecraft (A, B, C).  To fulfill the secondary objectives, the satellites do also carry other instruments, such as an accelerometer expected to measure the non-gravitational forces acting on each satellite. However, the quality of the data retrieved from this instrument was not at the anticipated level and, therefore, the post-processing required to calibrate the signal was significant. Therefore, initially the calibration focused on Swarm C only because it had the best signal-to-noise ratio of the constellation. For this satellite the calibrated accelerometer data are available since the beginning of the mission and they are disseminated bi-monthly. At the end of 2021, the first Swarm A dataset was released and it comprises some months in 2014. Swarm A and C, called the “lower pair”, have flown side-by-side for most of the mission with a separation that spanned from four to ten seconds. Therefore, their measurements are supposed to be nearly identical after calibration.A recent publication, which is discussed in this talk, demonstrated that a comparison between Swarm A and Swarm C calibrated accelerometer dataset shows the expected correlation. After applying a high-pass filter to both satellites’ dataset, very similar features are visible at the equator and at the poles. The “long time scale” events at the equator show a correlation between the equatorial mass anomaly and the equatorial ionization anomaly. At the poles, the “short time scale” events can be related to the Polar Cap index and to the field-aligned currents, which are measured on board by the Swarm magnetometers. Furthermore, these features agree with previous literature based on CHAMP and GRACE data.For the first time the Swarm accelerometer data deliver scientific results, in particular in the field of thermosphere and ionosphere coupling.
Sensitivity Analysis of Flood Risk Estimation under Nonstationary Conditions: A Case Study of the Weihe River, China
Authors: Xiong Bin , Zheng Shuchen , Xiong Lihua , Xu Chong-Yu
Published: February 2023

Flood risk has been increasing in many basins of the world, due to the global water cycle change driving by the global climate warming. To deal with the nonstationary properties of hydrological extremes, some new concepts, methods and models on flood frequency analysis and risk assessment are developed and applied. However, the robustness of nonstationary frequency analysis models, e.g. those based on the Generalized Additive Models for Location, Scale and Shape, is yet a big concern because the uncertainty of the parameters introduced by the methods and its impact on design flood values are difficult to quantify. This study aims to develop sensitivity degree indexes to assess the robustness of the nonstationary estimation of flood risk rates and their attributions, based on classical and Bayesian statistics, respectively. The results of the case study showed that the proposed method was efficient in identifying significant driving factors of nonstationary flood frequency; the results of the sensitivity index based on the Bayesian statistics showed that the uncertain degree of the nonstationary flood risk estimation increases with uncertain degree of the nonstationary model parameters as expected, but the sensitivity degree is decreased. It is indicated that the degree of influence of model parameters uncertainty on the risk estimation results is model dependent. This study will benefit the application of nonstationary frequency analysis methods in the flood risk assessment and flood design inference fields.Keywords: Flood frequency analysis; Flood risk; Non-stationarity; Attribution*This work was supported by the Research Council of Norway (FRINATEK Project 274310).
Seismic site characterization around the COSC-2 drill hole (Järpen, Sweden)
Authors: Bräunig Lena , Buske Stefan , Giese Rüdiger , Jaksch Katrin , Kück Jochem , Krastel Sebastian , Grob Henrik , Juhlin Christopher , Lorenz Henning , Brodic Bojan
Published: February 2023

Within the ICDP-funded project COSC (Collisional Orogeny in the Scandinavian Caledonides), mountain building processes are investigated with the help of two ~2.5 km deep fully cored boreholes in Central Sweden. Drilled in 2014, borehole COSC-1 near Åre studied the emplacement of the high-grade metamorphic allochthons and obtained a section through the Lower Seve Nappe as well as the underlying mylonite zone. The second borehole COSC-2, drilled in 2020 near Järpen/Mörsil, focuses on defining the character and age of deformation of the underlying greenschist facies thrust-sheets, the main Caledonian décollement and the Precambrian basement.An extended walkaway VSP survey at the COSC-2 drill site was performed in September-October 2021.   This study aims to support the geological interpretation with a high-resolution 3D image of the subsurface in the direct vicinity of the borehole. This allows the determination of the origin of the basement reflections and reveals the nature of the main décollement as well as the degree of basement thrusting.  Two 2D surface seismic lines approximately perpendicular to each other (North to South, West to East) and centered around the COSC-2 drill site were acquired using single (1C) and three-component (3C) geophones at 5-30m intervals. Furthermore, the West-East line was extended by 30 geophones at 100m intervals on each line end to allow the registration of wide-angle shots. A 32 t Vibroseis source operated along both lines with source point distances of 100 m within the central part of the line and 500 m at the wide-angle stations, respectively. Ocean bottom seismometers (OBS) were deployed on the bottom of a lake north of the borehole along a ~1.5 km portion of the North-South line. An airgun source was activated on this part of the profile. Along the entire borehole down to a depth of 2.26 km a 3C geophone chain recorded the seismic wavefield from all source points with a geophone spacing of 10 m, complemented by the recording from one single zero-offset source point with a geophone spacing of 2 m.The obtained surface seismic and VSP data set exhibits exceptionally good quality and shows many pronounced and clear reflections in the raw gathers. They are observed even at the largest source-receiver offsets (~11 km) and are visible at two-way-traveltimes up to 3-4 s, corresponding to structures at a depth of approximately 11 km. We present results of the ongoing surface seismic data processing and analysis, including a P-wave velocity model obtained from first arrival traveltime tomography, an analysis of seismic anisotropy related to the geological structures in the area and a first imaging result from the surface seismic data.
Early melt-season nutrient and inorganic carbon sediment-water fluxes in the Bering and Chukchi Seas
Authors: Barrett Lauren , Vlahos Penny , Hammond Doug
Published: February 2023

The Bering and Chukchi Seas are important oceanic regions of carbon sequestration, owing to enhanced gas solubility in cold surface waters and the rapid uptake of carbon dioxide (CO2) during intense spring blooms. The biogeochemical impacts of decreasing sea ice extent and earlier onset of spring ice melt in this region are yet uncertain. As these marginal seas of the western Arctic Ocean are quite shallow, mostly <60m depth, there is extensive interaction across air-sea-sediment boundaries, but the transformations and fluxes of inorganic carbon in Bering and Chukchi Sea sediments have not been directly quantified. In May-June 2021, we collected water column samples at 14 stations and sediment cores at 5 stations spanning the eastern Bering Sea and southern and eastern Chukchi Sea. Duplicate cores were incubated for several days at in situ temperature, and core-top water was sampled to estimate inorganic carbon and nutrient fluxes. The stations spanned a range of surface ice coverage history, from greater than one month to less than one day of ice-free conditions. In the Chukchi Sea, salinity-normalized bottom water nutrient and dissolved inorganic carbon (DIC) concentrations increased northward, indicating a net input of remineralization products, although effluxes of these parameters from the sediments decreased northward. Moving northward in the Chukchi Sea, the surface water had greater sea ice concentrations, inhibiting surface productivity and air-sea exchange. This may have reduced the rain of labile carbon to the seafloor, resulting in the decreased benthic remineralization. The combination of increasing northward ice coverage and the northward flow of nutrient and IC-rich Pacific-sourced waters influences the bottom-water concentration of remineralization products and sediment-water fluxes. We expect our northeastern Chukchi Sea flux observations are representative of baseline low wintertime sediment-water flux conditions, while the more southerly stations represent at least one month post-ice melt benthic fluxes when surface water productivity is high and the air-water-sediment system openly interacts. We note that some duplicate core measurements were highly heterogeneous, especially in the Bering Sea, illustrating the dynamic nature of this macrofauna-dominated benthic environment and the range of possible fluxes under different rates of bioturbation. While these observations may serve as a seasonal reference, they may also demonstrate how sedimentary fluxes will evolve under future conditions that are expected when sea ice retreats earlier in the season. Here we present our sediment-water flux and water column DIC and nutrient measurements and place them in context with previous work in the region.
Imaging medium changes during a hydraulic stimulation using the distortion matrix framework: case of an Enhanced Geothermal System (EGS) in Espoo, Finland.
Authors: Compaire Nicolas , Campillo Michel , Hillers Gregor , Touma Rita , Aubry Alexandre
Published: February 2023

In 2018, the company St1 Oy performed an Enhanced Geothermal System (EGS) experiment using near-real-time seismic monitoring as feedback for the pumping procedure and thus allowing the control of the induced seismicity. Between 4 June and 22 July (49 days), ~18,000 cubic meters of water was injected at around 6 km depth beneath the University campus in Otaniemi, Espoo, Finland (Kwiatek el al. 2019). The hydraulic stimulation and post-stimulation stages were monitored by a temporary ~100 three-components geophone network installed by the Institute of Seismology, University of Finland (Hillers et al. 2020). If the requirements for induced seismicity have been successfully met, the medium changes produced by the hydraulic stimulation remain unclear. Especially with regard to the activation or opening of cracks. Recent application of the distortion matrix concept (Badon et al. 2020) in seismology (Touma et al. 2021) allows us to consider resolving some of these questions by imaging the distribution of the scatterers in the medium during the different injection stages. The distortion matrix operator makes it possible to correct a large part of the aberrations present in images obtained by focusing in depth a reflection matrix recorded at the surface. The phase distortions of the seismic wavefield due to complex velocity distributions can be recovered for any virtual source in the medium by comparing the recorded reflection matrix to the ideal geometric wave-front corresponding to this virtual source. By taking advantage of this powerful approach this study present 3D images of the volume surrounding the injection well of the EGS experiment.
Hot weather impacts on urban indoor air temperature assessed through citizen science observations in the Netherlands
Authors: Peerlings Esther , Steeneveld Gert-Jan
Published: February 2023

Due to climate change and urbanization, the world's population is increasingly exposed to extreme heat, posing a threat to public health. Despite people spending ~90% of their time indoors, heat effects in buildings have been studied far less than outdoor heat island effects. This study aims to observe, understand and model the behaviour of indoor air temperatures (Tin) during summer heat. As a proof of concept, we present and analyse up to 27 years of individual Tin timeseries of seven citizen weather stations (CWS) across the Netherlands. First, we find that typically Tin increases slower, but also cools down slower than Tout with a lag difference of ~130 minutes in the diurnal cycle. We demonstrate that nocturnal indoor human thermal comfort (HTC) can be worse than outdoor HTC even for days after a heatwave.Second, to model Tin behaviour, we simulate six-hour changes in Tin behaviour with a physics-based statistical model by Vant-Hull et al. (2018) that has an outdoor conduction, indoor conduction and solar transfer component. Preliminary results of this computationally-fast model for each of the seven houses are promising, showing on average a R-squared of 0.74 and a root mean squared error of 0.13 K. Third, in the next research steps, we are also interested in how Tin may evolve due to climate change. We will study this by converting the Tin measurements to 2050 and 2085 values based on the Royal Netherlands Meteorological Institute 2014 climate scenarios (or 2023 if available).Finally, we will scale up our proof-of-concept analyses to 100 indoor CWS placed in Amsterdam. The participating households receive a CWS for three years to measure their indoor climate – temperature, relative humidity, CO2 concentrations – in the bedroom and living room. Based on our insights, we will make recommendations for climate-sensitive urban design to reduce indoor heat stress.
The connection between soil water content and stream flow in the experimental catchment of Magyaregregy (Hungary)
Authors: Koch Dániel , Majer Fruzsina Kata , Keve Gábor , Bene Katalin
Published: February 2023

With the increasingly negative impact of climate change, there is a significant need for more accurate runoff measurements in steep-sloped catchments to understand and predict the impact of extreme weather conditions. The spatial and temporal variability of precipitation, different soil parameters, soil moisture and infiltration characteristics significantly influence the surface runoff and channel flow processes in natural catchments.During the last 5 years, the Faculty of Water Sciences of the University of Public Service developed a complex meteorological and hydrological monitoring system at Várvölgyi creek which is a 5.95 km2 sub-catchment of Völgységi creek watershed. The small steep-sloped experimental catchment lies on the border of Magyaregregy. This small village located in the eastern Mecsek region in the southern part of Hungary. The research program aims to better understand each runoff process element in the watershed. Five years ago, a meteorological station was installed to improve rainfall measurement accuracy. In addition to meteorological and flow measurements, soil moisture sensors were recently installed at three locations to record soil moisture data at six different depths. In this paper, we investigate the connection between soil water content and streamflow.The research presented in the article was carried out within the framework of the Széchenyi Plan Plus program with the support of the RRF 2.3.1 21 2022 00008 project.
Improving the forecast quality of near-term climate projections in the Mediterranean region
Authors: Cos Josep , Doblas-Reyes Francisco , Marcos Raül , Donat Markus G
Published: February 2023

The Mediterranean region is often considered a climate change hotspot. State of the art climate projections display a large uncertainty due to factors such as the modeling approach or variability phasing, in particular for projections of the next few decades. With the great amount of climate information from the last Coupled Model Intercomparison Project (CMIP6), it is desirable to constrain the multi-model multi-member ensemble for the near-term future to obtain more robust and better performing projections. We explore different subsetting methods that select those members that better capture the variability at the starting date of the projection’s study period. To find the best information we explore variations of different parameters in the selection method based on relevant climate drivers in the Mediterranean region. Such parameters are the reference against which the best members are selected, and comprise: the time period used, the constraining regions considered and the variable or metric that drive the constraint. We find that these subsetting methods can improve the accuracy of near-term climate projections for the next 20 years compared to the unconstrained projections. This evaluation of the results allows us to make informed and robust decisions about the near-term future projections based on quality estimates borrowed from climate prediction practices.
Dependence of Early Warning Signals on Time Scale Separation
Authors: Kypke Kolja
Published: February 2023

The  two-dimensional stochastic FitzHugh-Nagumo (sFHN) model is a popular idealization of the dynamics of the temperature of Greenland during the Last Glacial Period as measured in the ice-core record. Specifically, the sFHN model is used to simulate the Dansgaard-Oeschger (D-O) events, which are sharp changes in temperature and the most prominent example of abrupt climate change in the paleoclimate. The theory of early warning signals (EWS) has been applied to D-O events, specifically the critical slowdown corresponding to an increase in variance and autocorrelation of the climate signal right before approaching a bifurcation point where the system changes state. There is a debate in the literature on the state of these in the record of D-O events, with studies demonstrating both the absence and existence of these EWS. A desirable element of the sFHN is that it is a fast-slow system with multiple timescales. For a very large time scale separation, a quasi-steady-state in the slow variable causes the system to act as a bistable potential, where EWS do not precede an abrupt change in state. On the other hand, for a smaller time scale separation, the system displays clear EWS. The subject of this study is the case of intermediate time scale separation and its effects on EWS, along with an exploration of the physical implications of the results. 
General drivers of microbial carbon use efficiency in soils
Authors: Schroeder Julia , Schneider Florian , Tebbe Christoph C. , Poeplau Christopher
Published: February 2023

The efficiency by which soil microbes direct metabolised carbon to their growth, i.e. the microbial carbon use efficiency (CUE), is hypothesised to be driven by soil pH, nutrient stoichiometry and the microbial community composition (e.g. Fungi-to-Bacteria ratio). Despite extensive research it remains difficult to identify general trends in how these drivers affect CUE and results of individual studies often point in different directions. To unravel general trends, we aggregated a unique data set of samples analysed using the 18O-labelling technique - all derived from the same laboratory - to gain deeper insights into the relationship between CUE and pH, CN ratio and the relative abundance of domains (based on 16S and ITS gene copy numbers by qPCR). To date, the growing data set comprises 685 observations of 18O-CUE, including samples from 41 individual sites under three different land use types (forest, managed grassland, cropland) from tropical to subarctic climate. A Random Forest model and a linear mixed-effects model approach were used to analyse the data. Preliminary results on a filtered and aggregated subset (n= 221; aggregated to reduce the heterogeneity of the data set structure) suggest that the CUE is strongly dependent on soil pH, following a U-shaped curve. The relationship between CUE and pH was found negative for pH < 5.5 and positive for pH ≥ 6.5, while overall the CUE was found to be negatively correlated to soil C:N ratio. Additional data on climate (MAT, MAP), soil texture, and soil microbial community will complement the analysis.
Assessing geologic inheritance and strain partitionning in an intraplate block corner junction area. Insights from high-resolution topographic data and multiple Quaternary dating methods in the Arpa Basin.
Authors: Rizza Magali , Pousse Léa , Fleury Jules , Braucher Régis , Baikulov Sultan , Rahimdinov Erkin , Abdrakhmatov Kanatbek
Published: February 2023

In the central Tien Shan, the largest intracontinental strike-slip fault is the northwest-trending Karatau-Talas-Fergana Fault (TFF), the southern extent of which remains debated. It is proposed that the TFF terminates in the Atushi Basin or continues southwards into the Tarim Basin.We investigated the Arpa Basin, where the southernmost TFF segment intersects the South Tien Shan suture (STSs). High-resolution topographic data (derived from photogrammetry using SPOT 6/7 and drone images) reveal clear evidence of recent faulting along two parallel, reverse segments running at the toe of the mountain range and within the basin. Detailed mapping also revealed offsets in moraines and uplifted, abandoned alluvial surfaces. The combination of multiple dating methods (10Be, 26Al, 36Cl, OSL and 14C) at four sites across the Arpa Basin allows us to constrain late Quaternary slip rates for the last 100 ka.In addition, the contradiction between the southwards TFF’s geological trace, which is easily observed on satellite images, and the absence of Quaternary surface ruptures associated with recent faulting leads us to propose that the two fault segments in the Arpa Basin reactivated the STSs and presently mark the southern termination of the active TFF in a horsetail thrust fault system. 
Development of an In-Progress Forecasting Model to Forecast Radiation Dose Rates Once a Ground-Level Enchancement has Begun
Authors: Davis Chris , Waterfall Charlotte , Lei Fan , Dalla Silvia , Ryden Keith , Clewer Ben , Dyer Clive
Published: February 2023

During major solar energetic particle events, radiation dose rates in Earth's atmosphere at aviation altitudes can increase by orders of magnitude relative to dose rates during quiet times in events known as Ground-Level Enhancements (GLEs). In the case of events of a scale such that they occur once every few decades, radiation dose rates could become high enough that they pose a threat to aircraft crew and electronics. It is not currently possible to predict when such an event will occur, and existing software systems are only capable of nowcasting the current atmospheric radiation dose rates using real-time data sources. However, while it is not possible to forecast when a major event will occur, it may be possible to generate forecasts for radiation dose rates once an event has been registered to have begun. The ability to provide forecasts for dose rates once a GLE has started would be vital for airlines and for pilots in any future where aircraft might be rerouted to avoid regions of high radiation, as pilots need to be able to know not just their current radiation dose rates but radiation dose rates at possible locations where their plane might be in say half an hour's time. We report on the development of a software system to do this. This 'in-progress' radiation dose rate forecasting system will be developed by integrating the FOrecasting Relativistic particles during GLE Events (FORGE) system being developed at the University of Central Lancashire with an anisotropic extension to the Models for Atmospheric Ionising Radiation Effects+ (MAIRE+) system being developed at the University of Surrey. We report on the development of both of these systems and their integration.
Dynamical pathways for pan-Atlantic compound cold and windy extremes
Authors: Riboldi Jacopo , Dorrington Josh , Leeding Richard , Segalini Antonio , Messori Gabriele
Published: February 2023

North American cold spells tend to co-occur with extreme wind and precipitation events over Europe, but the physical mechanisms behind such “pan-Atlantic” compound extremes have not been fully clarified yet. Rather than proposing a single mechanism, we discuss how cold spells over a single North American region can be connected with wind extremes over different European regions through separate, physically consistent dynamical pathways. The first one involves the propagation of a Rossby wave train from the Pacific Ocean, and is associated with windstorms over north-western Europe in the 5-10 days after the cold spell peak. The second one is associated with a high-latitude anticyclone over the North Atlantic and an equatorward-shifted jet, leading to windstorms over south-western Europe already in the days preceding the cold spell peak.The same dynamical pathways can be independently retrieved from a cluster analysis based on the temporal evolution of the North Atlantic circulation in the days preceding North American cold spells. Such an analysis highlights significantly different stratospheric circulation patterns between the two pathways, with cold spells of the second pathway tied to a weaker than usual stratospheric polar vortex, and an enhanced occurrence of sudden stratospheric warmings.
ECS (“Extremely Compact Sources”): a new method for potential field data filtering.
Authors: Maiolino Marco , Florio Giovanni
Published: February 2023

Filtering is a fundamental procedure that precedes further quantitative interpretations. In the potential fields case, filtering is used to separate and discriminate the different contributions of a given dataset. In this note we describe a potential field filtering technique based on a “Extremely Compact Sources” (ECS) approach. ECS filtering method allows us to solve the problem of the interfering anomalies, that could hide the real amplitude and shape of the single contributions. The interference phenomena may involve the superimposition of a regional field generated by deep sources in the study area on local anomalies, or the superimposition of anomalies having similar wavelengths. While many methods have been developed during the years to try to separate regional from local fields, fewer methods have been developed to address the separation of interfering  anomalies caused by similar sources. The ECS technique exploits the inherent ambiguity of potential fields to retrieve an extremely compact source model in which sources are well separated each one from other. In this way, the filtering process can be done through a simple "muting" process (setting the physical property of the cells relative to the unwanted contributions to 0) directly in the source domain. We show applications of the ECS technique to both synthetic and real anomalies to prove the validity of the methodology for both separation of interfering anomalies and filtering of regional fields.
Tag jumping may produce major distortion of paleoecological reconstructions derived using metabarcoding approaches
Authors: Rodriguez-Martinez Saúl , Morlock Marina , Huang Doreen Y-T. , Klaminder Jonatan
Published: February 2023

AbstractAnalysis of DNA fragments preserved in natural archives, such as lake sediments and buried soil layers, has increased our understanding of past environments and their organism communities.  High throughput sequencing of genetic material from these matrixes and the linkage of DNA barcode databases (e.g. metabarcoding) has played, and still play, an important role for palaeoecological reconstructions. Yet, scrutinization of results derived using metabarcoding approaches – methods that fairly recently have become common within environmental science – is critical. Tag jumping is a process where sample-specific labels (tags), added to DNA sequences to allow identification of individual samples in a pooled DNA library, are unintentionally changed during sampling handling (during the end repair step). If occurring, tag jumping can result in DNA sequences being associated with the wrong sample. Nevertheless, tag jumping is rarely discussed within the paleoecological community, and the importance of the process remains largely unquantified.Using example datasets from lake sediments and soils, we assessed the impact of tag jumping on metabarcoding data and how it affects paleo-reconstructions. We find that tag jumping can lead to substantial false positive detection of taxa in sedimentary samples. That tag jumping generated a very characteristic topological sample cross-contamination pattern allowed us to estimate that up to 80% of data in some data sets was distorted by this process(Rodriguez‐Martinez et al., 2023). We further compared a set of sedimentary DNA samples processed according to commonly applied, tag-jumping sensitive protocols with the same set of samples processed following a tag jumping free protocol. Our results suggest that tag jumping can affect paleoecological interpretations by: i) masking significant environmental change at a Holocene time-scale by making samples more similar; and; ii) adding species to sediment samples where they were not originally present (false positive detections). Our data clearly shows that tag jumping can represent a major source of bias for paleoecological reconstructions based on metabarcoding techniques. Importantly, the problem is easily circumvented if the right protocols are used. ReferencesRodriguez‐Martinez, S., Klaminder, J., Morlock, M.A., Dalén, L., Huang, D.Y., 2023. The topological nature of tag jumping in environmental DNA metabarcoding studies. Mol. Ecol. Resour. 1755–0998.13745. https://doi.org/10.1111/1755-0998.13745
Unraveling the subsurface fault geometry of small to moderate strike-slip earthquakes: an example from the Valdelsa basin in Southern Tuscany (Italy)
Authors: Mirabella Francesco , Braun Thomas , Brogi Andrea , Capezzuoli Enrico
Published: February 2023

The connection between faults at surface, their subsurface geometry and earthquakes is a long-debated issue. The attempt of making such correlation is even more difficult when earthquakes are not strong enough to reach and break the topographic surface. Even in the latter case, the subsurface geometry of earthquake-causative-faults is not a trivial issue because of the difficulty of imaging the subsurface setting at seismogenic depths.We take as an example the area of southern Tuscany in Central Italy where several M≈4 strike-slip earthquakes were registered recently, the latest of which occurred in May 2022.The seismogenic role of transversal SW-NE striking faults in this area is debated as they do not show clear surface evidence even when releasing earthquakes and their recent and/or Quaternary evidence often a matter of discussion. For these reasons they can be extremely dangerous as they receive relatively little attention and are difficult to identify.We integrate seismic reflection profiles, surface kinematic data and the relocation of seismological data in order to identify and characterize strike-slip active faults geometry at depth in the Valdelsa basin of southern Tuscany. We show that the Montespertoli NE-trending fault, part of a wider (15–20 km) crustal-scale shear zone, is possibly responsible for the 2016 M=3.9 Castelfiorentino earthquake and discuss the role of transversal SW-NE striking faults in controlling the inner Northern Apennines seismicity.