bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanism/s of deformation and strength of experimentally deformed hornblende-rich amphibolite with a strong pre-existing texture
Authors: Boneh Yuval , Sarah Incel , Renner Joerg
Published: March 2022

Amphibole is an important mineral in rocks of the lower crust and in subduction zones, forming as the product of metamorphic reactions and hydration of mafic rocks. As such, the textural and rheological properties of amphibole are of relevance for assessing the physical properties of these tectonic provinces. Aggregates containing amphibole grains often exhibit a strong texture, i.e., a crystallographic preferred orientation (CPO). Since amphibole possesses inherent anisotropic properties, the CPO will affect the bulk strength and elastic properties. However, amphibole’s rheological behavior is not well understood as its capability to deform purely via plastic deformation remains unresolved, previous studies suggesting numerous deformation mechanisms such as semi-brittle and cataclastic flow, dissolution precipitation, dislocation creep, recrystallization, micro-twinning, and diffusion assisted creep. Here, we use pre-textured natural samples cored at 60° to the foliation and lineation to investigate the deformation mechanism/s activated in a polycrystalline aggregate/rock of well-oriented amphibolite-rich hornblende. Samples from the Mamonia complex (Cyprus) with hornblende as the dominant mineral (> 70 % modal fraction) and strong initial alignment of the [001] axis were deformed using a Griggs-type solid-medium apparatus. Experiments were run at 1 GPa confining pressure, temperatures of 400 to 800 °C, and a strain rate of ~10-5 1/s. Samples show temperature-dependent differential stress that falls below the Goetze criteria (i.e., below the confining pressure, 1 GPa) - ~700, 500, and 200 MPa for samples deformed at 400, 600, and 800 °C, respectively. Microstructural analysis using Electron backscatter diffraction (EBSD) reveals folding and kink bands, accommodated by both plastic mechanisms, via dislocation glide on the hornblende easy slip system, and brittle mechanisms, via micro-fracturing along the crystal cleavage (110). We discuss the implications of the interplay and contribution of different deformation mechanisms for our ability to translate laboratory experiments to flow laws for the lower mantle and subduction zone interfaces.
Analysis of individual learning outcomes of students and teachers in the citizen science project TeaTime4Schools
Authors: Wawra Anna , Scheuch Martin , Stürmer Bernhard , Sanden Taru
Published: March 2022

Only a few of the increasing number of citizen science projects set out to determine the projects impact on diverse learning outcomes of citizen scientists. However, besides pure completion of project activities and data collection, measurable benefits as individual learning outcomes (ILOs) (Phillips et al. 2014) should reward voluntary work.

Within the citizen science project „TeaTime4Schools“, Austrian students in the range of 13 to 18 years collected data as a group activity in a teacher guided school context; tea bags were buried into soil to investigate litter decomposition. In an online questionnaire a set of selected scales of ILOs (Phillips et al. 2014, Keleman-Finan et al. 2018, Wilde et al. 2009) were applied to test those ILOs of students who participated in TeaTime4Schools. Several indicators (scales for project-related response, interest in science, interest in soil, environmental activism, and self-efficacy) were specifically tailored from these evaluation frameworks to measure four main learning outcomes: interest, motivation, behavior, self-efficacy. In total, 106 valid replies of students were analyzed. In addition, 21 teachers who participated in TeaTime4Schools, answered a separate online questionnaire that directly asked about quality and liking of methods used in the project based on suggested scales about learning tasks of University College for Agricultural and Environmental Education (2015), which were modified for the purpose of this study. Findings of our research will be presented.
Assessing Environmental Benefits in the Hydro-economic Model of the Ebro Basin
Authors: Crespo Daniel , Albiac José , Dinar Ariel , Esteban Encarna , Kahil Taher
Published: March 2022

The increasing concern about the degradation of water-dependent ecosystems calls for consideration of ecosystem benefits in water management decision-making. Sustainable water management requires adequate economic and biophysical information on water systems that support both human activities and natural ecosystems. This information is essential for assessing the impact of water allocation options on social welfare. This paper evaluates various alternative water management policies by including the spatial and sectoral interrelationships between the economic and environmental uses of water. A hydro-economic model is developed to analyze water management policies in response to reduced water availability in the Ebro Basin of Spain. The originality in our contribution is the integration of environmental benefits across the basin, by using endemic biophysical information that relates stream flows and ecosystem status in the Ebro Basin. The results show the enhancement of social welfare that can be achieved by protecting environmental flows, and the tradeoffs between economic and environmental benefits under alternative adaptation strategies. The introduction of water markets is a policy that maximizes the private benefits of economic activities, but disregards environmental benefits. The results show that the practiced institutional policy where stakeholders cooperate inside the basin water authority, provides lower private benefits but higher environmental benefits compared to those obtained under water markets, especially under situations of severe droughts. However, the water authority is not allocating enough environmental flows to optimize social welfare. This study informs strategies for protection of environmental flows in the Ebro Basin, which is a compelling decision under the imminent climate change impacts on water availability in coming decades
Geochemical investigations of 100 superficial soils observed by Sentinel 2 and PRISMA
Authors: Salani Gian Marco , Lissoni Michele , Natali Stefano , Bianchini Gianluca
Published: March 2022

Geochemical investigations of agricultural soils are fundamental to characterize pedosphere dynamics that sustain ecosystem services linked with agriculture. Parameters like soil moisture, soil organic matter (SOM), and soil organic carbon (SOC) are strong instruments to evaluate carbon sink potential.

Satellite Earth Observation is a significant source of free data that can be linked to soil characteristics and dynamics and employed to produce temporal series. Access to these data is nowadays facilitated by platforms such as ADAM (https://adamplatform.eu), which allow users to quickly search for, visualize and subset data products, greatly reducing the volume of data that end users must handle.

In this work we demonstrate the usefulness of such systems by carrying out a geochemical investigation of 100 superficial (0-15 cm) soil samples collected in the province of Ferrara (North-Eastern Italy) and using the ADAM platform to associate to each a time series of Sentinel 2 data. The samples were collected in October 2021 in fields that were ploughed or mono-cultivated at maize, soybean, rice, and winter vegetables. To obtain the average soil properties over a spatial scale larger than the satellite sensor resolution, we adopted a composite sampling strategy, merging 5 sub-samples collected at the vertexes and at the center of a 30x30 m2 area. Soil granulometry was recognized from clay to medium sand, with exception of peat deposits. Soil moisture, and SOM, contents were estimated by loss on ignition (LOI), respectively at 105°C (values from 0.3 to 7.4 wt%), and 550°C (values from 2.1 to 21.0 wt%). SOC contents (values from 0.7 to 9.3 wt%) were determined through DIN19539 analysis performed with an Elementar soliTOC Cube. Using the ADAM platform, we associated a temporal series from 2016 to 2021 of the Sentinel 2 NDVI data product to each sampling location, using a cloud coverage mask to eliminate values taken on cloudy days. Localized phenological cycles for each year are recognizable in the remotely-sensed data. Hence, our database describes for each parcel, geochemical parameters and vegetative temporal series.

In a separate study, we also attempted to train a neural network to predict geochemical properties from the soil spectrum measured by the hyperspectral satellite PRISMA. We used the geochemical properties of our 100 samples as training data, associated with the PRISMA spectra of the sampling locations measured on April 7 2020, when, according to our NDVI data, none was covered in vegetation.
Quantification of methane fluxes from water bodies on the floodplain forest ecosystem level
Authors: Kowalska Natalia , Bednarik Adam , Jocher Georg
Published: March 2022

Freshwaters (rivers, streams, ponds, reservoirs) are a well-recognized source of methane (CH4) characterised by large spatiotemporal variability. However, the determination of the role of water bodies for net CH4 exchange on forest ecosystem scale is very scarce. Our study aimed to determine the importance of individual emission pathways for total CH4 fluxes from streams and to verify the possible identification and quantification of CH4 fluxes from water bodies on the floodplain forest ecosystem level. In 2020, we measured CH4 fluxes by diffusion and ebullition from a lowland stream flowing through the lowland broadleaf mixed temperate forest at Lanžhot in the Czech Republic (Central Europe). For this purpose, 18 bubble traps were installed at three stream sites and periodically sampled for gas volume and its CH4 content from April to December. Diffusive CH4 fluxes from water were measured at 14 days intervals with a floating chamber connected to a portable GHG analyser. Simultaneously, CH4 exchange was determined on the forest ecosystem scale using the eddy covariance method (EC). We hypothesized initially that due to a relatively small area of water bodies in the EC footprint and a high probability of CH4 consumption by soils, CH4 emissions will be detectable by EC only in case that water bodies will create the potential CH4 emission hotspots in the studied ecosystem. We found that the investigated stream was a significant source of CH4 (mean 260 ± 107 mg CH4 m-2 day-1) with ebullition as a dominant pathway (55 – 85%) of CH4 release throughout the whole monitored time period. Furthermore, first EC results showed that the whole ecosystem is a small but constant CH4 source as we observed an average emission flux of 16 ± 18 mg CH4 m-2 day-1 over the period June to November 2021. In-depth investigations of the potential CH4 sources and sinks within the studied ecosystem should answer the question of how the relative proportion of water surfaces and related CH4 emission corresponds to whole ecosystem CH4 fluxes.
Application of satellite and reanalysis precipitation for hydrological modeling in data-scarce Porijõgi catchment, Estonia 
Authors: Moges Desalew Meseret , Kmoch Alexander , Uuemaa Evelyn
Published: March 2022

The lack of adequate and reliable gauge observations has long been a major obstacle for hydrological modeling. This study focuses on a comprehensive evaluation of hydrological applicability of satellite and reanalysis-based precipitation products (IMERG, ERA5, PERSIANN-CDR, SM2RASC, and CMORPH-CRT) in Porijõgi catchment, Estonia. The evaluations were carried out in two parts: 1) evaluating the quality of satellite and reanalysis-based precipitation products relative to gauge observations, 2) comparing gauge-simulated streamflow with satellite and reanalysis-based simulations using the SWAT model.  Results show reasonable variation in the detection capability of satellite and reanalysis-based precipitation products with further influence on the streamflow simulations. IMERG, ERA5, and PERSIANN-CDR show better detection capability for the monthly precipitation and demonstrated reliable performance in simulating the monthly streamflow. However, SM2RASC and CMORPH-CRT products have a common tendency to underestimate the gauged precipitation and fail to show satisfactory performance in streamflow simulation. Overall, our findings suggest that satellite and reanalysis-based precipitation products can be a priori alternative sources of precipitation data for hydrological applications in poorly gauged areas. However, along with the efforts to improve satellite and reanalysis-based precipitation products, it is important to develop more effective bias adjustment techniques at a daily scale.    
Assessing the influence of the vegetation on the evapotranspiration from a wetland – a case study from northwest Germany based on in-situ measurements at different scales
Authors: Herbst Mathias , Matuschek David , Falge Eva
Published: March 2022

Evapotranspiration (ET) from wetlands is often considered to occur at a potential rate. However, depending on the structural and physiological traits of the dominating plant species, actual ET can deviate substantially from potential ET. Here we present a case study from a restored wetland in north-western Germany which is dominated by moor grass (Molinia caerulea). ET was measured over three years by means of the Bowen Ratio method, leaf transpiration and leaf resistance of moor grass were measured with a porometer, and both green and total leaf area index were measured optically and manually.

Whilst actual and potential ET were practically similar during the period from late summer to the end of winter, they differed significantly from the beginning of spring to early summer and on hot summer days. Two likely reasons for this marked seasonality could be identified. (1) Molinia leaves responded very sensitively to the vapour pressure deficit of the air, independent of the unlimited water supply to its roots. (2) A thick mat of dead leaves covered the surface in spring before and while the new leaves emerged and acted as an efficient protection cover against evaporation.

The SVAT model ‘AMBAV’ was developed by the German Meteorological Service and is operationally used in agrometeorological applications. Based on the Bowen Ratio and in-situ plant physiological data, it was newly parameterised for the investigated type of wetland. If run with weather data from a nearby station, AMBAV could verify the observed seasonal pattern of actual ET from the moor grass dominated wetland. The results demonstrate that the present vegetation reduces wetland ET and thus contributes to the maintenance of a high water table in the restored wetland.
Raman Spectroscopic and Microbial Analysis of Microbial Mat Hosted Gypsum from the Dohat Faishakh Sabkha in Qatar and its Astrobiological Implications
Authors: Diloreto Zachary , Bontognali Tomaso , Shaharyar Ahmad Mirza , Dittrich Maria
Published: March 2022

The discovery of gypsum (CaSO4●2H2O) on Mars by the NASA Mars Exploration Rover Opportunity has corroborated past models about the early composition of the Red Planet. In extreme environments, minerals, such as gypsum, which are formed through the evaporation of water, can act as a refuge for extremophilic microorganisms. After providing a refuge from desiccation, rapid temperature fluctuations, and elevated levels of UV-radiation, gypsum can preserve biomarkers by sealing them. To better understand the geobiological interactions of pigments and other biomarkers possibly encapsulated in a gypsum matrix, samples of gypsum collected from a depth of 25cm within microbial mats in the Dohat Faishakh sabkha in Qatar were examined. The Dohat Faishakh sabkha is considered an Earth analogue to past evaporitic environments on Mars due to its extremely high salinity, harsh desiccation, and intense levels of UV-radiation. The aim of this work was to holistically evaluate the buried microbial community and gypsum-hosted biomarkers to gain insight into the best practices for Raman signal detection. 16s rRNA analyses was employed to determine organisms present and their aptitude for producing biomarkers. Raman microscopic analysis was applied to prove whether any biomarkers were trapped within the gypsum matrix. We observed that gypsum formed in a layer heavily dominated by halophilic archaea (>50% total abundance) and organic matter produced by microorganisms was encapsulated resulting in distinct Raman spectra. Several types of organic molecules were identified including carotenoids, chlorophylls, scytonemin and phycobiliproteins suggesting that complex signatures were preserved in gypsum.
Forecasting impacts of climate change on plantation carbon sink capability
Authors: Li Hung-En , Cheng Su-Ting
Published: March 2022

In the face of climate change, the government of Taiwan requires new mitigation policies and implementation strategies. As forest plantations are commonly accepted as great carbon sinks, developing reliable carbon systems linking forestry carbon sequestration into green carbon credits in the economic sector requires synergic integration to examine potential carbon sink capability of forest plantations under the ever-changing climate. In this regard, this study developed a process-based stand growth model based on the structure of the Physiological Principles for Predicting Growth (3-PG) for carbon sequestration estimations of Sugi plantations in the National Taiwan University (NTU) Experimental Forest. The model considered monthly solar radiation, temperature, precipitation, vapor pressure deficit (VPD), and the atmospheric carbon dioxide concentration to simulate dynamic biomass production, and then allocated the simulated biomass to root, stem, and foliage by allometric equations fitted to biomass data from the SugiHinoki Database. After that, the mortality of stand was determined by using a zero-inflated Poisson modelling on long-term growth data collected by the NTU Experimental Forest during 1921-2019. In addition, we performed a scenario analysis to forecast future stand growth under 4 climate scenarios of RCP2.6, RCP4.5, RCP6, and RCP8.5. Results revealed higher annual biomass increment (around 4 t ha-1y-1) in the end of the century in RCP6.0 and RCP8.5, and lower increment (around 2.5 t ha-1y-1) in RCP2.6 and RCP4.5. A step-wise multiple linear regression analysis on the simulated growth data and climatic inputs revealed stronger positive impact of CO2 concentration than precipitation on unit biomass primary production (NPP/Biomass). Temperature had comparable counter impact against precipitation, and solar radiation showed the least negative influence on unit biomass primary production. Based on this process-based stand growth model, we are able to dig into the relation between climatic variables and carbon sequestration rate, and help sketch prospect of plantations in the carbon market for plantation managers, investors, and policy makers.
Seasonal and regional characteristics of carbon monoxide anomalies as seen by IAGOS between 2002 and 2019:
Authors: Lebourgeois Thibaut , Sauvage Bastien , Wolff Pawel , Josse Beatrice , Marecal Virginie , Thouret Valerie
Published: March 2022

IAGOS (www.iagos.org) is a European research infrastructure using commercial aircraft to measure the atmospheric composition. In particular, IAGOS provides regular carbon monoxide (CO) data since December 2001. In this study we use eighteen years of available data (from 2002 to 2019) to investigate CO anomalies throughout the entire flight i.e. vertical profiles over airports and upper troposphere/lower stratosphere (UTLS) at cruise altitude.

IAGOS flight track is divided into four distinctive vertical groups: boundary layer, middle troposphere, upper troposphere and lower stratosphere. The entire IAGOS data set has been split in 18 regions according to the geographical variability (e.g. continents over northern mid-latitudes, tropics, etc ...) and the different seasonal cycles of CO. CO anomalies are defined as air masses with CO mixing ratios above the 95th/99th percentile of the regional/seasonal/vertical distribution. This unique data set allows us to look at the variety of CO anomalies between regions and seasons.

Soft-io module which couples emission inventories and Lagrangian modelling along IAGOS flight track is used to quantify in which proportion those anomalies are linked to biomass burning and anthropogenic emissions.

The origin of those events presents high seasonal discrepancies (drought season and cold season) but also inter-annual variabilities. Anomalies coming from anthropogenic sources hit the most heavily on the lower part of the atmosphere of densely populated areas. However, none of the region, whatever the altitude range, are spared by anthropogenic pollution. Anomalies coming from biomass burning present large regional variability caused by weather conditions and biomass differences. We quantified these local and temporal variabilities to better understand processes affecting CO anomalies in the troposphere and UTLS.
Ensemble Empirical Mode Decomposition of the variability of precipitation over the Tianshan Mountains, Central Asia
Authors: Guan Xuefeng , Yao Junqiang , Schneider Christoph
Published: March 2022

Considerable knowledge gaps remain in understanding the spatial and temporal patterns of precipitation in the Tianshan, a large system of mountain ranges located in Central Asia. Based on the Global Precipitation Climatology Centre (GPCC) data set and NCEP/NACR reanalysis data, this study investigates the precipitation variations over the Tianshan Mountains on different time scales using the Ensemble Empirical Mode Decomposition (EEMD), and a subsequent attribution analysis with respect to large-scale climate modes.

During 1950-2016, the annual precipitation in most of the Tianshan regions showed an increasing trend with the exception of its wettest sub-regions, the Western Tianshan. In addition to the overall trend, the annual precipitation in Tianshan shows high-frequency variations of 3-year and 6-year quasi-periods and low-frequency variations of 12-year and 27-year quasi-periods. Winter precipitation in the Tianshan Mountains exhibits multi-decadal oscillations with periods of 26.8 and 44.7 years, with similar multi-decadal variability as the East Atlantic-Western Russia (EATL/WRUS) teleconnection pattern. The enhanced meridional characteristics of the EATL/WRUS trigger more water vapor fluxes from low-latitude oceanic regions, resulting in a wet period of Tianshan in winter after 1988. Similarly, summer precipitation in the Tianshan Mountains entered a wet period after 1986. The Scandinavian (SCAND) teleconnection pattern is significantly negatively correlated with Tianshan summer precipitation. During the negative phase of SCAND in summer, strong high pressure over the Ural Mountains and low pressure over Central Asia combine to induce enhanced conveying of water vapour to the Tianshan from the Arctic Ocean. Furthermore, the Silk Road pattern (SRP) and East Asia-Pacific teleconnection (EAP) have affected Tianshan summer precipitation for the periods 1964-1984 and 1985-2004.
Unified parameterization of turbulence and boundary layer clouds using the updated two-energies turbulence scheme 
Authors: Schmidli Juerg , Bašták Ďurán Ivan , Sakradzija Mirjana
Published: March 2022

The unified parameterization of turbulence and clouds in the atmospheric boundary layer is one of the challenges in current weather and climate models. An update of the two-energy turbulence scheme is presented, the 2TE+APDF scheme. The original version of the two-energy scheme is able to successfully model shallow convection without the need of an additional parameterization for non-local fluxes. However, the performance of the two-energy scheme is worse in stratocumulus cases, where it tends to overestimate the erosion of the stable layers. To alleviate this problem, we propose several modifications: an update of the stability parameter to consider local stratification, a more flexible computation of the turbulence length scale, and the introduction of the entropy potential temperature to distinguish between a shallow convection and a stratocumulus regime. In addition, the two-energy scheme is coupled to a simplified assumed PDF method in order to achieve a more universal representation of the cloudy regimes. The updated turbulence scheme is evaluated for several idealized cases and one selected real case in the ICON modeling framework. The results show that the updated scheme corrects the overmixing problem in the stratocumulus cases. The performance of the updated scheme is comparable to the operational setup of the ICON model, and can be thus used instead of the operational turbulence and shallow convection scheme in ICON. Additionally, the updated scheme improves the coupling with dynamics, which is beneficial for the modeling of coherent flow structures in the ABL, such as, for example, cloud streets.
Aeolian River Dust in Central and Southern Taiwan Rivers: Spatial-Temporal Characterization and Public Health Implication
Authors: Chen Chun-Kuang , Tsai Christina W.
Published: March 2022

Aeolian river dust has been one of the significant local air quality concerns in central and southern Taiwan for a long time. Aeolian river dust is not only affecting local visibility and air quality but also causing adverse health effects. It has been demonstrated that long-term exposure to PM10, even the low-level concentrations, may induce adverse health effects such as pulmonary, respiratory diseases and even death. Moreover, Taiwan Environmental Protection Administration (EPA) indicated nine river-dust events occurring in western Taiwan between 1994 and 2017. However, due to global climate change, the frequency and intensity of extreme events, such as droughts, are increasing significantly, which may contribute to the occurrence of river dust events. Furthermore, in Taiwan, most studies have only focused on the Asian dust storms transported from China, while the spatial-temporal characterization and health implication of river dust events is still not widely understood. Therefore, in this study, to explore the causes and effects of river dust in Taiwan, we mainly analyze the PM10 concentration, relevant hydro-meteorological factors (temperature, precipitation, relative humidity, wind speed, and river water level), drought events, and medical data of respiratory diseases by using time-frequency analysis. Time-frequency analysis is a tool that allows us to investigate the characteristic time scale and energy distribution of the signals since the signals are most likely to be both nonlinear and nonstationary, which cannot be adaptively analyzed by traditional data-analysis methods such as Fourier transform. Thus, the method of improved complete ensemble empirical mode decomposition with adaptive noise (ICEEMDAN) is introduced in this study to adaptively decompose hydro-meteorological time series and medical data into their intrinsic mode functions (IMFs) and a trend. Moreover, the time-dependent intrinsic correlation method (TDIC) is introduced to calculate the running correlation coefficient between two IMFs with the sliding window in different time scales. After the ICEEMDAN and TDIC work, the correlation between river dust and relevant hydro-meteorological factors can be identified. The impact of frequency and intensity of droughts on river dust events in Taiwan can be explored, and then the association between respiratory diseases and river dust can be determined. It is hoped that the results of this study can assist in promoting the related air pollution policies in protecting residents and reducing the risk of disaster to people, particularly during droughts when most of the river dust events prevail.
High-resolution sensing of alpine vegetation location properties by multi-source earth observation techniques
Authors: Rutzinger Martin , Kollert Andreas , Mayr Andreas , Müller Lukas , Hiebl Benedikt , Bremer Magnus , Dullinger Stefan
Published: March 2022

Vegetation cover and plant species distribution in high mountain regions strongly depend on climatic, topographic, and geomorphic conditions, which often vary at small spatial scales. This contribution presents a concept and first results for producing high-resolution maps of soil and surface temperature, snow cover and geomorphic disturbance. These datasets will allow us to infer a variety of variables key to alpine plant life, such as temperature sums and their seasonal variation as well as timing and duration of snow cover. Close-range and satellite remote sensing time-series are used in combination with extended fieldwork and meteorological records to bridge different acquisition scales in space and time. Analysis and modeling will benefit from a high-density sampling scheme for soil temperature, snow cover and vegetation that balances the statistical representation of study site properties (such as topography and vegetation cover) against practical limitations, such as site accessibility in high-alpine environments. By integrating micro-scale location properties with existing and newly developed process models, we strive to get a better understanding of how micro-, local-, or regional factors, and the interaction among these, govern the distribution of alpine flora now and in a warming climate.

 

This work has been conducted within the MICROCLIM project (http://microclim.mountainresearch.at/), which has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant agreement No. 883669).
Impact of Atmospheric Stability on Vertical Propagation of Submeso and Coherent Structure in a Dense Amazon Forest
Authors: Cava Daniela , Mortarini Luca , Quaresma Dias Júnior Cléo , Brondani Daiane , Acevedo Otavio , Oliveira Pablo , Giostra Umberto , Manzi Antonio Ocimar , Araújo Alessandro , Tsokankunku Anywhere , Sörgel Matthias
Published: March 2022

Observations of the vertical structure of the turbulent flow in different stability regimes above and within the Amazon Forest at the Amazon Tall Tower Observatory (ATTO) site are presented. The shear length scale at the canopy top together with the coherent turbulent structures time and separation length scale were evaluated to determine influence of stability on the inception and development of the roughness sublayer. Five stability regimes were identified. The definition of an intense table regime allowed the identification of a peculiar condition characterized by low-wind and weak coherent structures confined close to the canopy top and producing negligible transport. Submeso motions dominate the flow dynamics in this regime both above and inside the roughness sublayer.

The shear length scale increases with decreasing stability, presenting two asymptotes for large unstable and stable stratification and a linear behaviour close to neutral stratification. The coherent structure time and length scales are detected using an original method based on the autocorrelation functions of 5-min subsets of turbulent quantities. The vertical time scale is larger in neutral conditions and decreases for both increasing and decreasing stability, while the separation length scale at the canopy top presents a linear dependence on the shear length scale, whose slope is maximum in neutral conditions and decreases departing from neutrality. A new parameterization describing the dependence of the coherent eddies’ separation length scale on the h/L stability parameter is presented.
Crucial consistency of the water balance in urban land surface models
Authors: Jongen Harro , Lipson Mathew , Teuling Ryan , Grimmond Sue , Steeneveld Gert-Jan
Published: March 2022

The development of urban areas impacts the local climate and hydrology. Cities have been modelled with an array of models with different complexities. These models are called urban land surface models (ULSM) and focus on radiation, and turbulent sensible and latent heat fluxes. Grimmond et al. (2010) evaluated these models finding that the latent heat flux is the most challenging to simulate. This flux is part of both the energy balance and water balance, as the latent heat flux is the energy equivalent of the mass evapotranspiration. Thus, the hydrological circumstances may be crucial to correctly model the turbulent heat fluxes. However, the representation of the water balance in these models has not been the focus of a multi-model evaluation. As a part of the follow-up project to the work by Grimmond et al. and Urban-PLUMBER we evaluated the representation of the water balance in ULSMs with varying complexity and representation of the water balance. It is difficult to evaluate the water balance fluxes against observations, as not all terms are observed. For example, changes in water storage require knowledge of the state of all the individual stores (e.g. soil moisture, detention ponds). Analysis of 14 models shows a large spread in the magnitude of the individual water balance fluxes. The rate of reduction of the latent heat flux/evapotranspiration during periods without rainfall varies widely between models, consistent with literature (e.g. Jongen et al., 2022). Initial analysis suggests that models that simulate the water balance and conserve mass are more likely to accurately simulate turbulent heat fluxes. It is thus crucial that both the water and energy balance are accounted for in future urban model improvements.
Spring discharge, transit times and intermittency in an alpine catchment: how geomorphology shapes the spatio-temporal dynamics?
Authors: Roques Clément , Chatton Eliot , Chrétien Gaël , Servière Laurent , Pasquier Xavier , Abhervé Ronan , Gauvain Alexandre , Aquilina Luc , de Dreuzy Jean-Raynald
Published: March 2022

We investigate spatial and temporal behaviors of spring discharge, transit times and intermittency of a network of springs located in an alpine catchment (Natural conservation area of the Massif of Saint-Barthélemy, Pyrenees, France). Field observations have revealed unprecedented variability of behaviors across the catchment, with springs involving sustained high discharge rates during baseflow while others showing intermittency of wetting and drying periods. This dynamic is expected to be directly dependent on the volume and transmissivity of the connected aquifer set by specific geomorphological (topography scaling, rockslides, deep seated landslides, detritic sediments) and geological features (lithology, faults).  Here we aim at understanding the relative controls of those factors in controlling the observed hydrogeological behaviors across the catchment.

We performed two field missions during 2021 high and low flow regimes. More than 20 flowing springs and wetlands have been systematically mapped and sampled for environmental tracer analysis. We found that about 30% of the stream and wetland network contract between high and low flows. The springs responsible for this intermittence are connected to high transmissive shallow aquifers with low storage capacities organized within shallow soils and rockslides. However, perennial springs are influenced by deep groundwater flow paths within the bedrock. The analysis of anthropogenic dissolved gases like CFCs and SF6 revealed an average transit time of the order of 10 years for perennial springs with important variabilities across the catchment. The relatively high residence times is also confirmed by high Helium concentrations. We used the gathered dataset to calibrate a hydrogeological model designed to test the relative controls from specific geomorphological and geological characteristics. By comparing models with different structural settings, we found that topography and aquifer compartmentalization, through the decreasing trend in hydraulic conductivities, are key parameters in setting the spatio-temporal pattern of saturated areas and the distribution of transit times across the catchment. In perspective, we discuss the potential evolution of the extent, discharge magnitude and the transit time of seeping groundwater under changing recharge scenarios.  
New insights into the brittle evolution along the passive continental margin of Western Norway from U-Pb calcite dating 
Authors: Hestnes Åse , Drost Kerstin , Gasser Deta , Jacobs Joachim , Scheiber Thomas , Sømme Tor , Chew David
Published: March 2022

We here present the first U-Pb geochronology from calcites precipitated on fracture and fault surfaces from the passive continental margin of Western Norway. The evolution of passive continental rifted margins is reflected in complex fracture and fault networks which have been activated and reactivated through time. Constraining the timing of fault activity and fracturing can assist in revealing the interaction between tectonic processes and the topographic response onshore. Recently, U-Pb calcite dating has proven to be a useful tool to complement other geochronological methods and to produce more complete records of brittle deformation in different geological settings. In this study, we collected 35 calcite samples from different fault and fracture planes in Western Norway, 14 of which gave reliable U-Pb dates. The onshore field area is located at the junction of the NE-SW trending Norwegian Sea and the N-S trending North Sea. 1) The oldest calcites measured are from the Dalsfjord fault, a complex brittle fault related to the Nordfjord-Sogn Detachment Zone. The ages obtained from a green cataclasite indicate fluid flow and calcite precipitation around 208 ± 25 Ma and 205 ± 6 Ma, whereas a reddish cataclasite and fault gouge zone were dated 142 ± 15 Ma. 2) Two calcite samples from the northern part of the study area were collected along fractures parallel to the Møre-Trøndelag Fault Complex and yield dates of 89 ± 4 Ma and 79 ± 3 Ma. 3) Five samples from variously oriented fractures and faults spread over the field area gave dates of 69 ± 2 Ma, 67 ±15 Ma, 65 ± 2 Ma, 64 ± 2 Ma and 59 ± 2 Ma. These ages can be linked to the base Tertiary unconformity in the offshore stratigraphic record of the northern North Sea interpreted to be caused by onshore uplift. Several processes have been proposed to cause a possible uplift during this time span; a) regional influence of the Icelandic mantle plume, b) rift footwall uplift, c) climatically controlled topographic changes. 4) Five samples from across the field area yield dates of 49 ± 3 Ma, 35 ± 1 Ma, 21 ± 1 Ma, 5.5 ± 4.5 Ma and 0.8 ± 0.1 Ma. All these calcites precipitated on faults and fractures striking NE-SW, and its formation may be related to relaxation along the passive margin. The dated calcites from this study provide Cenozoic brittle deformation ages much younger than previously obtained by other geochronological methods, possibly allowing to decipher the youngest brittle tectonic evolution of the margin in unprecedented detail.
Landslide fissures and fractures mapping and classification from UAV imagery
Authors: Sandric Ionut Cosmin , Ilinca Viorel , Irimia Radu , Chitu Zenaida
Published: March 2022

Mapping landslide fissures and fractures are essential in understanding the landslide dynamics and evolution across space and time. In the current study, a particular focus on detecting, mapping, and classifying the fissures and fractures located along the landslide bodies and in their vicinity has been given. The depth, direction and width of each fissure and fracture are related to the stress and strain imposed on the landslide body. Moreover, the spatial distribution of these can indicate areas where the landslide can extend, mainly if they are located in the upper part of the main landslide scarp. Even though the fissures and fractures leave a distinct pattern on the landslide body when they are fresh or when there is a high contrast between the bare soil and the surrounding vegetation, these patterns are gradually diminished by time, making their detection difficult. The problem of landslide cracks mapping in various environmental conditions and having different ages was tackled in the current study by using very high spatial resolution UAV aerial imagery and derived products in conjunction with deep learning models. Several flights using DJI Phantom 4 RTK were performed in the Romanian Subcarpathians in areas with both recent and old landslide occurrences. The sampling dataset was collected with Esri ArcGIS Pro on products obtained by the fusion of orthoimages with terrain parameters. The dataset was fed into a Mask RCNN deep learning model with a Resnet152 architecture and trained for 50 epochs. The training and validation reached accuracies of 0.77 and 0.70, estimated from the Intersect over Union metric. No significant differences were recorded between the detection on only orthoimages and the detection on products obtained from the fusion of orthoimages with other terrain parameters. A slight decrease in the validation accuracy was observed when the images were collected on older landslides compared to recent landslides. Overall, the detection of fissures and fractures using deep learning and UAV aerial imagery proved reliable if the UAV flights are flown quickly after the landslide occurrence or after recent rainfalls.

 Acknowledgement

This work was supported by a grant of the Romanian Ministry of Education and Research, CCCDI - UEFISCDI, project number PN-III-P2-2.1-PED-2019-5152, within PNCDI III, project coordinator Ionuț Șandric (https://slidemap.gmrsg.ro), and by the project PN19450103 (project coordinator Viorel Ilinca, Geological Institute of Romania).
Model-based identification of snow properties from full-field measurements
Authors: Rosendahl Philipp , Adam Valentin , Rheinschmidt Florian , Bergfeld Bastian , van Herwijnen Alec , Weißgraeber Philipp
Published: March 2022

The accurate measurement of elastic and fracture properties of snow is challenging but crucial for the modeling of avalanche events. We propose the combination of a closed-form model of the mechanical behavior of layered snowpacks with full-field displacement measurements of propagation saw tests (PSTs) for the identification of the elastic properties of all snow layers and of the fracture toughness of weak layers.

The analytical model provides snow cover deformations, weak-layer stresses and energy release rates of cracks within the weak-layer for arbitrarily layered snowpacks. It can be used for real-time analyses of skier-loaded slopes and for stability tests such as the propagation saw test. Its real-time evaluation is particularly important for the present application.

Full-field measurements of snow cover deformations during propagation saw tests can be obtained using digital image correlation. Recordings of a simple handheld camera suffice for the present application.

The elastic material properties of each layer can then be obtained by fitting the modeled displacement field to the recorded field. The solution of this optimization problem requires many evaluations of the model with varied material parameters of all layers but finally yields the elastic properties of each layer of the snow cover.

Finally, the model allows for the calculation of weak-layer fracture toughnesses using the above determined material properties and the critical crack length of the PST experiment. The results indicate an increasing slab stiffness and an increasing weak-layer fracture toughness throughout one winter season.
Understanding the surface temperature response and its uncertainty to CO2, CH4, black carbon, and sulfate
Authors: Nordling Kalle , Korhonen Hannele , Räisänen Jouni , Partanen Antti-Ilari , Samset Bjørn , Merikanto Joonas
Published: March 2022

Regional climate change is what people will experience on their daily lives. However, the regional temperature changes in response to changing greenhouse gases and aerosols vary between current climate models. The origin of these inter-model differences is poorly understood . Here we relate temperature changes in response to different anthropogenic climate forcing agents to changes in atmospheric and oceanic energy fluxes.

We use climate model simulations forced by idealized perturbations in four major anthropogenic climate forcing agents (CO2, CH4, sulfate, and black carbon aerosols) from Precipitation Driver Response Model Intercomparison Project (PDRMIP) climate experiments for six climate models (CanESM2, HadGEM2-ES, NCAR-CESM1-CAM4, NorESM1, MIROC-SPRINTARS, GISS-E2). We decompose the regional temperature change to its  different energy budget components: change in longwave and shortwave fluxes under clear-sky and cloudy conditions, surface albedo changes, and oceanic and atmospheric energy transport. We also analyze the regional model-to-model temperature response spread due to each of these components.

The main physical processes driving global temperature responses vary between forcing agents, but for all forcing agents the model-to-model spread in temperature responses is dominated by differences in modeled changes in effective longwave clear-sky emissivity. Furthermore, in polar regions for all forcing agents, the differences in surface albedo change are a major contributor to temperature response and its spread between models. Our results provide valuable information on what is causing the spread between climate models’ response to various forcing agents. 
System dynamics modelling of linked land-coast-sea systems for water quality management under different RCP-SSP scenarios
Authors: Seifollahi-Aghmiuni Samaneh , Kalantari Zahra , Destouni Georgia
Published: March 2022

The human-nature interactions driving water quality deterioration in linked land-coast-sea systems are complex, including numerous components across different water environments. This complexity has led to many unsuccessful or insufficient efforts for water quality improvement, as seen, for example, in the Baltic Sea and its coasts that suffer from severe eutrophication long after several policies and measures have been repeatedly taken for mitigating excess nutrient loads. Considering the Swedish water management district of Northern Baltic Proper and its surrounding coastal areas and associated marine waters of the Baltic Sea, this study has used a system dynamics (SD) modelling approach to investigate possible future shifts in regional water availability and quality under different regional change scenarios. The SD model is developed based on a stakeholder-identified problem-oriented system network diagram that includes key land-coast-sea system interactions. The scenarios are developed based on scenarios of Representative Concentration Pathways (RCPs) and Shared Socio-economic Pathways (SSPs), complemented with insights from the IPCC report ‘Global warming of 1.5°C’ to reflect possible future changes in human pressures and hydro-climatic conditions. Relevant RCPs and SSPs are downscaled to region-specific change scenarios for associated model input variables, and their combined impacts on system behavior are evaluated using various key performance indicators defined for socioeconomic sectors, natural water systems, and policy and management aspects. Results show that further investment and development are needed for urban storm water handling and wastewater treatment from both water quantity and quality perspectives. Water quality management strategies also need to account for and target long-lived nutrient legacy sources to mitigate their further contribution to water quality problems in the study region. Furthermore, policy targets defined for water quality improvement, for example, in the Baltic Sea Action Plan, need to be updated based on regional water-related impacts of projected hydro-climatic changes and expected future socioeconomic conditions. The updated targets, however, can only be achieved if synergistic management measures are taken across the land-coast-sea continuum. SD modelling and scenario analysis, as established, applied and will be further developed in this study, can support identification of efficient policy and management strategies for water quality improvement by assessing their performance and exploring possible sustainable solutions under different future development scenarios.