bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative analysis of the incoming surface and outgoing top of atmosphere solar radiation based on MERRA-2 & CERES data
Authors: Stamatis Michael , Hatzianastassiou Nikolaos , Korras Carraca Marios Bruno , Matsoukas Christos , Wild Martin , Vardavas Ilias
Published: March 2021

The incoming solar radiation at the top of the atmosphere (TOA), and especially at the Earth’s surface, determines the energy balance of our planet and regulates its climate. During the last decades, variations in the incoming surface solar radiation (SSR) have been observed, which depend on the atmosphere’s transparency. This phenomenon, known as global dimming and brightening (GDB), plays an important role in climate change and global warming.
The present study examines the variability and changes of both SSR and the outgoing solar radiation at the TOA (OSR) based on long-term satellite data and ground truth measurements, but also reanalysis data, also with an aim to inter-compare and validate the changes of SSR (ΔSSR or GDB) and OSR (ΔOSR) in order to ensure the highest accuracy of the findings. For this analysis, mean monthly SSR and OSR fluxes are used at the global scale and over the last several decades. More specifically, SSR and OSR solar fluxes are used from the Modern-Era Retrospective Analysis for Research and Applications v.2 (MERRA-2) reanalysis data for the 40-year period 01/1980 - 12/2020 and from the satellite Clouds and the Earth's Radiant Energy System Energy Balanced and Filled (CERES-EBAF) database for the 20-year period 03/2000 - 07/2020.
The spatial resolution of CERES-EBAF dataset is 1°×1° latitude and longitude. MERRA-2 data, originally provided on a 0.5°×0.625° horizontal grid, are regridded on the CERES-EBAF spatial resolution (1°×1°). The SSR and ΔSSR fluxes from MERRA-2 and CERES are compared to each other, and they are both assessed through comparisons against ground measurements from the two major reference station networks, namely the Global Energy Balance Archive (GEBA), and the Baseline Surface Radiation Network (BSRN). The OSR and ΔOSR fluxes from MERRA-2 are assessed through comparison against corresponding fluxes from the CERES satellite measurements. The data analysis examines the spatio-temporal distribution and the trends of SSR (ΔSSR or GDB) and OSR, using both radiation fluxes and their deseasonalized anomalies. Special emphasis is given to the accurate estimation of GDB and the associated uncertainty, while attempting to reduce this uncertainty using the results of the analysis at the top of the atmosphere.
Recurrence-Based Quantification of Multi-Scale Dynamical Complexity in the Earth’s Magnetosphere
Authors: Donner Reik
Published: March 2021

The Earth’s magnetosphere is characterized by a considerable degree of dynamical complexity resulting from the interaction of different multiscale processes, which can be both directly driven/triggered by changes of the interplanetary medium condition, and due to internal processes of the magnetosphere. This complexity can be characterized by following both “classical” and “new” dynamical system tools. Recent work has demonstrated that recurrence plot based techniques may play a pivotal role in such an assessment.

In this presentation, I will summarize some recent results on applications of recurrence quantification analysis and recurrence network analysis to different geomagnetic indices (Dst, SYM-H, ASY-H, AE) reflecting the variability of the Earth’s electromagnetic environment at different time-scales and magnetic latitudes. In addition, the same techniques are applied to some essential properties of the solar wind which are likely to have a relevant effect on geomagnetic field fluctuations and might serve as triggers of instability leading to geospace magnetic storms and/or magnetospheric substorms. The obtained findings underline that dynamical fluctuations of the geomagnetic field during periods of magnetospheric quiescence and storminess indeed exhibit distinctively different levels of dynamical complexity. Moreover, they provide additional evidence for a time-scale separation in magnetospheric dynamics that is further characterized by employing some multi-scale version of recurrence analysis utilizing a continuous wavelet transform of the signals of interest. The corresponding results can be of potential relevance for the development of improved approaches for space weather modelling and forecasting.

 

References:

R.V. Donner, V. Stolbova, G. Balasis, J.F. Donges, M. Georgiou, S. Potirakis, J. Kurths: Temporal organization of magnetospheric fluctuations unveiled by recurrence patterns in the Dst index. Chaos, 28, 085716 (2018)

R.V. Donner, G. Balasis, V. Stolbova, M. Georgiou, M. Wiedermann, J. Kurths: Recurrence based quantification of dynamical complexity in the Earth's magnetosphere at geospace storm timescales. Journal of Geophysical Research - Space Physics, 124, 90-108 (2019)

J. Lekscha, R.V. Donner: Areawise significance tests for windowed recurrence network analysis. Proceedings of the Royal Society A, 475 (2228), 20190161 (2019)

T. Alberti, J. Lekscha, G. Consolini, P. De Michelis, R.V. Donner: Disentangling nonlinear geomagnetic variability during magnetic storms and quiescence by timescale dependent recurrence properties. Journal of Space Weather and Space Climate, 10, 25 (2020)
Unraveling potential biases in U-Pb detrital zircon record induced by high-temperature metamorphism (> 850 ºC)
Authors: Tedeschi Mahyra , Reis Humberto , Stutenbecker Laura , Kuchenbecker Matheus , Ribeiro Bruno , Barrote Vitor , Vieira Pedro Leonardo , Lana Cristiano
Published: March 2021

Detrital zircon records are prone to several sources of bias that can compromise sediment provenance investigations based on U-Pb ages. High-temperature metamorphism (>850 ºC) is herewith addressed as a natural cause of bias since U-Pb zircon data from rocks submitted to these extreme, often prolonged conditions, frequently display protracted apparent concordant geochronological U-Pb records. The resulting spectrum can originate from disturbance of the primary U-Pb zircon system, likewise from subsequent recrystallization and crystallization processes during multiple and/or prolonged metamorphic events. Consequently, a high-grade metamorphosed igneous rock can exhibit a zircon age spectrum similar to that produced by polymict sedimentary rocks, thereby inducing provenance misinterpretations if this rock becomes a source for a sediment. A polymict sedimentary source that undergoes such high temperatures could potentially generate an even more intricate spectrum. Archean, Neoproterozoic and Paleozoic metamorphic rocks from the literature, dated by different techniques (SIMS and LA-ICP-MS), are employed as examples to demonstrate the resulting complications.  The compilation shows that (1) high-temperature metamorphism may generate age peaks of unclear or lacking geological meaning, and (2) the interpretation of detrital zircon age spectra depends on the timing of the metamorphic event (pre- or post-depositional). When high-temperature metamorphic rocks are eroded in uplifted areas, the youngest population of a detrital spectrum represents the maximum depositional age through metamorphic zircon from the source. If a sedimentary succession was subjected to high-temperature metamorphic conditions after deposition, its youngest zircon population more likely records the metamorphism, and the maximum depositional age, as well as older sources cannot be directly accessed. To evaluate the presence of high-temperature metamorphism-related bias in a given detrital zircon sample, we suggest a workflow for data acquisition and interpretation, combining a multi-proxy approach with: in situ U-Pb dating coupled with Hf analyses to retrieve the isotopic composition of the sources, and the integration of a petrochronological investigation to typify fingerprints of the (ultra)high-temperature metamorphic event.
Joint inversion of converted and surface waves for characterization of geothermal fields
Authors: Granados Chavarria Ivan , Calò Marco , Bodin Thomas , Figueroa Soto Angel
Published: March 2021

Joint inversion of surfaces and teleseismic converted waves is commonly used to retrieve seismic structures beneath a seismic station. Currently, this approach is routinely applied at global and regional scale to probe the structures of the mantle and the lower-crust. However, the difficulty to retrieve reliable converted waves at high frequencies (> 1 Hz) makes challenging to apply this technique to resolve structures at shallow depths (<20 km). Here we explore the feasibility of using a trans-dimensional Bayesian scheme based on a reversible jump Markov Chains Monte Carlo method, to resolve shallow structure at local scale. We use phase and group velocity dispersion curves for Love and Rayleigh waves, from 0.5 to 10 s and tele-seismic converted waves in a distance range from 30o to 95o. We explore the ability of different approaches to retrieve high frequency converted phases that will be used in the framework of the Bayesian inversion. We present preliminary tests of the reliability of the method and applications to experimental data collected in the super-hot geothermal field of Los Humeros, México. This work is performed in the framework of the Mexican European consortium GeMex (Cooperation in Geothermal energy research Europe-Mexico, PT5.2 N: 267084 funded by CONACyT-SENER: S0019, 2015-04, and Horizon 2020, grant agreement No. 727550).
Testing the effects of durability (shell thickness) on species over-representation in death assemblages, a taphonomic baseline for conservation paleobiology
Authors: Tomašových Adam , Kidwell Susan M.
Published: March 2021

Differences in the taxonomic or functional composition of living and death assemblages is a key means of identifying the magnitude and drivers of past ecological changes in conservation paleobiology, especially when assessing the effects of anthropogenic impacts. However, such live-dead differences in species abundances can arise not only from ecological (stochastic or deterministic) changes in abundance over the duration of time averaging but also from interspecific differences in the postmortem durability of skeletal remains or from the lifespan of the individuals. Here, we attempt to directly incorporate the effects of durability on species abundances in death assemblages by modeling dead abundance as a function of species’ durability traits and using abundances in living assemblages as a prior. Species inferred to be negatively affected by anthropogenic impacts should be over-represented in death assemblages relative to their abundance in death assemblages predicted by the durability model (rather than just relative to their abundance in living assemblages). Using species-level durability trait data for bivalves (shell size, thickness, mineralogy, shell organic content, and life habit) from the southern California shelf, we find that, among these traits, valve thickness correlates consistently positively and at multiple spatial scales with the log of the dead:live ratio of species abundances, and accounts for ~20-30% of live-dead mismatch. Using this benchmark for the discordance that might be taphonomic in origin, we confirm that the over-representation of epifaunal suspension-feeders and siphonate deposit-feeders in death assemblages of the southern California shelf owes in fact to their ecological decline in recent centuries, even when accounting for their greater durability.
Evolutionary rescue can prevent rate-induced tipping in predator-prey systems
Authors: Feudel Ulrike , Vanselow Anna , Halekotte Lukas
Published: March 2021

Nowadays, populations are faced with unprecedented rates of global climate change, habitat fragmentation and destruction causing an accelerating conversion of their living conditions. Critical transitions in ecosystems, often called regime shifts, lead to sudden shifts in the dominance of species or even to species’ extinction and decline of biodiversity. Many regime shifts are explained as transitions between alternative stable states caused by (i) certain bifurcations when certain parameters or external forcing cross critical thresholds, (ii) fluctuations or (iii) extreme events. We address a fourth mechanism which does not require alternative states but instead, the system performs a large excursion away from its usual behaviour when environmental  conditions change too fast. During this excursion, the system can embrace dangerously, unexpected states. We demonstrate that predator-prey systems can exhibit a population collapse if the rate of environmental change crosses a certain critical rate. In reference to this critical rate of change which has to be surpassed, this transition is called rate-induced tipping (R-tipping). A further difference to the other three tipping mechanisms is that R-tipping mainly manifests during the transient dynamics – the dynamics before the long-term dynamics are reached.  Whether a system will track its usual state or will tip with the consequence of a possible extinction of a species depends crucially on the time scale relations between the ecological timescale and the time scale of environmental change as well as the initial condition. However, populations have the ability to respond to environmental change due to rapid evolution. Employing an eco-evolutionary model we show how such kind of adaptation can prevent rate-induced tipping in predator-prey systems. The corresponding mechanism, called evolutionary rescue, introduces a third timescale which needs to be taken into account. Only a large genetic variation within a population reflecting rapid evolution would be able to successfully counteract an overcritically fast environmental change.

 
Meteorological and fire impacts on tropospheric ozone concentration over tropical forest in the Congo Basin
Authors: Vieira Inês , Verbeeck Hans , Meunier Félicien , Peaucelle Marc , Lefevre Lodewijk , Cheesman Alexander , Sitch Stephen , Mbifo José , Boeckx Pascal , Bauters Marijn
Published: March 2021

Tropospheric ozone is a greenhouse gas, and high tropospheric ozone levels can directly impact plant growth and human health. In the Congo basin, simulations predict high ozone concentrations, induced by high ozone precursor (VOC and NOx) concentrations and high solar irradiation, which trigger the chemical reactions that form ozone. Additionally, biomass burning activities are widespread on the African continent, playing a crucial role in ozone precursor production. How these potentially high ozone levels impact tropical forest primary productivity remains poorly understood, and field-based ozone monitoring is completely lacking from the Congo basin. This study intends to show preliminary results from the first full year of in situ measurements of ozone concentration in the Congo Basin (i.e., Yangambi, Democratic Republic of the Congo). We show the relationships between meteorological variables (temperature, precipitation, radiation, wind direction and speed), fire occurrence (derived from remote sensing products) and ozone concentrations at a new continuous monitoring station in the heart of the Congo Basin. First results show higher daily mean ozone levels (e.g. 43 ppb registered in January 2020) during dry season months (December-February). We identify a strong diurnal cycle, where minimum values of ozone (almost near zero) are registered during night hours, and maximum values (near 100 ppb) are registered during the daytime. We also verify that around 2.5% of the ozone measurements exceeds a toxicity level (potential for ozone to damage vegetation) of 40 ppb. In the longer term, these measurements should improve the accuracy of future model simulations in the Congo Basin and will be used to assess the impact of ozone on the tropical forest’s primary productivity.
Exploring the diurnal cycle of Δ17O in CO2 at the ecosystem level
Authors: Koren Gerbrand , Adnew Getachew A. , Vilà-Guerau de Arellano Jordi , van der Molen Michiel K. , Kruijt Bart , Röckmann Thomas , Peters Wouter
Published: March 2021

The triple oxygen isotope signature Δ17O in atmospheric CO2 is a potential tracer for gross primary production (GPP). However, interpretation of Δ17O in atmospheric CO2 is complicated by the contributions from respired CO2, isotopic exchange with soil and ocean water, and the release of CO2 by fossil fuel combustion and biomass burning. We studied Δ17O in CO2 at the ecosystem level, which is the domain that integrates the contributions from vegetation and soil to the atmospheric signal.  

We report for the first time the observed diurnal variation of Δ17O in CO2, measured from air samples collected on 15-16 August 2019 at the mid-latitude pine forest Loobos (ICOS L2 ecosystem site). We also measured the isotopic signatures δ13C and δ18O in CO2 close to the surface (at 0.5 m height, inside the canopy) and from the top of the tower (1-2 m above the canopy). To support the interpretation of the measurements, we used a land-atmosphere model that satisfactorily reproduces the diurnal variability of the interaction between leaf/canopy and the convective boundary layer using mixed-layer theory assumptions (CLASS). Also, we used the global atmospheric transport model TM5 to (1) quantify the contribution of different sources that affect Δ17O in CO2 at Loobos; and (2) extend our analysis of the diurnal cycle to the global scale.  

Our methodology demonstrates the added value of isotope measurements at ICOS ecosystem and tall-tower sites, and how to integrate meteorological and ecological observations from the canopy up to the atmospheric boundary layer. This study contributes to our ongoing effort of creating an overview of different methods for quantifying photosynthesis from a top-down perspective (concentration-based methods and remote sensing) in a review paper for which we are open to other contributions. 
The Imperative of Open, Shared, Trusted (FAIR) Scientific Data: Accelerating for the Future
Authors: Hanson Brooks
Published: March 2021

The major societal challenges—ensuring a sustainable planet and ecosystems, with food, energy, water, health, and quality of life provided equitably—depend on convergent science grounded in the Earth and space sciences and broadly open, shared, and trusted (e.g., FAIR) data. Such data already provide enormous benefits (e.g, weather prediction; hazards avoidance and mitigation; precision navigation). In addition to being needed for these solutions, the integrity and trust in science and thus the solutions follows directly from open FAIR data. But many barriers hinder widespread practices and adoption. A number of concerned stakeholders are working on the technology and practices needed for FAIR workflows, and thanks to these efforts, the technical pieces for solutions are mostly in place. But a larger coordinated effort is needed around in particular (i) supporting the infrastructure needed globally, and (ii) developing the research culture and practices needed for universal FAIR data. The first challenge includes recognizing that science is now international and thus international FAIR data culture is essential. This requires greater urgent attention by the larger science stakeholders: societies, universities and research institutions, funders, and governments.
Deep Learning for Three-Dimensional Volumetric Recovery of Cloud Fields
Authors: Sde-Chen Yael , Schechner Yoav Y. , Holodovsky Vadim , Eytan Eshkol
Published: March 2021

Clouds are a key factor in Earth's energy budget and thus significantly affect climate and weather predictions. These effects are dominated by shallow warm clouds (shown by Sherwood et al., 2014, Zelinka et al., 2020) which tend to be small and heterogenous. Therefore, remote sensing of clouds and three-dimensional (3D) volumetric reconstruction of their internal properties are of significant importance.

Recovery of the volumetric information of the clouds relies on 3D radiative transfer, that models 3D multiple scattering. This model is complex and nonlinear. Thus, inverting the model poses a major challenge and typically requires using a simplification. A common relaxation assumes that clouds are horizontally uniform and infinitely broad, leading to one-dimensional modeling. However, generally this assumption is invalid since clouds are naturally highly heterogeneous. A novel alternative is to perform cloud retrieval by developing tools of 3D scattering tomography. Then, multiple satellite images of the clouds are acquired from different points of view. For example, simultaneous multi-view radiometric images of clouds are proposed by the CloudCT project, funded by the ERC. Unfortunately, 3D scattering tomography require high computational resources. This results, in practice, in slow run times and prevents large scale analysis. Moreover, existing scattering tomography is based on iterative optimization, which is sensitive to initialization.

In this work we introduce a deep neural network for 3D volumetric reconstruction of clouds. In recent years, supervised learning using deep neural networks has led to remarkable results in various fields ranging from computer vision to medical imaging. However, these deep learning techniques have not been extensively studied in the context of volumetric atmospheric science and specifically cloud research.

We present a convolutional neural network (CNN) whose architecture is inspired by the physical nature of clouds. Due to the lack of real-world datasets, we train the network in a supervised manner using a physics-based simulator that generates realistic volumetric cloud fields. In addition, we propose a hybrid approach, which combines the proposed neural network with an iterative physics-based optimization technique.

We demonstrate the recovery performance of our proposed method in cloud fields. In a single cloud-scale, our resulting quality is comparable to state-of-the-art methods, while run time improves by orders of magnitude. In contrast to existing physics-based methods, our network offers scalability, which enables the reconstruction of wider cloud fields. Finally, we show that the hybrid approach leads to improved retrieval in a fast process.
Anomalous transport of heat and salt by a long-lived anticyclonic eddy  in the northeast tropical Pacific Ocean
Authors: Purkiani Kaveh , Walter Maren , Haeckel Matthias , Schmidt Katja , Paul André , Vink Annemiek , Schulz Michael
Published: March 2021

During RV Sonne expedition SO268 to the northeast tropical Pacific Ocean between March and May 2019, the impact of a mesoscale eddy on the seawater properties was investigated by conducting a multiple of observations. A subsequent analysis of an altimeter data revealed the formation of an anticyclonic mesoscale eddy in the Tehuantepec gulf between 15 and 20 June 2018 with a mean radius of 185 km and an average speed of 13 cm/s. This extremely long-lived eddy carried sea-water characteristics from near coastal Mexican waters westward far into the open ocean. The water mass stayed largely isolated during the 11 months of travel time due to high rotational speed.

The eddy exhibited a conical-shape vertical structure with concurrent deepening of the main thermocline. The water in the eddy core showed an extreme positive temperature anomaly of 8◦C, a negative salinity anomaly of -0.5 psu and a positive dissolved oxygen concentration anomaly of +160 μmol/kg centered at 80 m depth. The sub-surface impact of the eddy is clearly evident in the temperature and salinity profiles at a depth of 1500 m. For dissolved oxygen the eddy-induced anomaly reached even deeper to the seafloor.

This study provides new insights to the offshore transport of heat and salt driven by the long-lived anticyclonic eddy in the northeast tropical Pacific Ocean. Considering the water column trapped within the eddy, a positive heat transport anomaly of 1-3 ×1011 W and a negative salt transport anomaly of -8×103 kg/s were estimated. However, due to the rare occurrence of long-lived anticyclone eddies in this region, they likely do not play a significant role in affecting the heat and salt balance of the northeastern tropical Pacific Ocean.
The role of large benthic sulfur bacteria in biogeochemical cycles - a model approach.
Authors: Herran Natalia , Schmidt Martin , Mohrholz Volker , Schulz-Vogt Heide
Published: March 2021

On the seabed of oxygen minimum zones (OMZ), embedded in organic-rich sediments, large sulfur bacteria (LSB) fulfil an important ecological role by detoxifying the overlying bottom waters. Thiomargarita Namibiensis and Beggiatoa spp. are chemoautotrophic microorganisms that reduce sulfur compounds to create biomass and link by doing so the carbon, sulfur, oxygen and nitrate cycle very efficiently. This particular ability make life in suboxic and hypoxic coastal waters feasible. Nevertheless, due to the complexity of sulfur oxidation and its various pathways the quantification of such activity is of great complexity. Hereby, we describe a model framework of LSB activity to implement intrinsic properties of the bacteria based on field observations and numerical modelling validations, linking the stoichiometry and energy conservation efficiency of LSB while counting for the reduced sulfur pools and its partitioning sub-products.
Resolving changes in arc magma volatile budgets over Myr timescales leading up to porphyry Cu formation 
Authors: Large Simon , Nathwani Chetan , Buret Yannick , Knott Tom , Wilkinson Jamie
Published: March 2021

The crustal-scale magmatic systems of Andean-style arcs produce thick volcanic deposits and abundant plutons that are emplaced into the crust. They can also generate spatially- and temporally-restricted, economically-important porphyry Cu deposits. These deposits are formed at the magmatic-hydrothermal transition and require significant amounts of volatiles and metals to be concentrated in the sub-volcanic environment. Thus, understanding the magmatic and tectonic processes acting within an arc segment and their effect on the volatile budgets of crustal magmas could be essential for identifying the constraining factors controlling the potential of a magmatic system to produce a porphyry deposit.

In this study we examine the magmatic evolution of the Rio Blanco-Los Bronces district, ~30 km northeast of Santiago, Chile, which is host to the Earth’s largest resource of Cu. Eocene to Early Miocene volcanic rocks were intruded by the Miocene San Francisco Batholith that, in turn, partially hosts intrusions related to the Late Miocene to Early Pliocene Rio Blanco-Los Bronces porphyry deposit cluster. We apply a combination of whole-rock, apatite and zircon geochemistry and zircon geochronology to the intrusive rock suite of the district to provide temporally- constrained geochemical information over the entire duration of batholith assembly and ore formation.

U-Pb geochronology reveals incremental assembly of the San Francisco Batholith by individual magma batches over >14Myr (~18 – 4 Ma), with ore formation occurring in discrete pulses in the last 3 Myr before cessation of intrusive activity within the district. Progressive changes in the trace element chemistry indicate crustal thickening and deeper magma evolution within the arc segment as a result of the subduction of the Juan Fernandez ridge. A temporal shift to elevated SO3 and Cl contents is recorded by zircon-hosted apatite inclusions from the intrusions with highest values occurring in porphyry intrusions directly associated with the ore forming events. These data suggest variable volatile budgets of magmas during zircon crystallisation and hint at crustal-scale controls on the porphyry ore-forming potential of an arc segment.

 
Three-dimensional electrical conductivity of the world ocean and seabed sediments: effect on EM induction responses
Authors: Grayver Alexander
Published: March 2021

This work presents global 3-D electrical conductivity atlas of the world ocean and seabed sediments. Ocean salinity and temperature data were converted to electrical conductivity by solving a thermodynamic equation of state of seawater. A sediment compaction model was used to estimate the depth-dependent electrical conductivity of the seabed sediments. Electromagnetic responses in a wide period band, including typical ranges used in CSEM, MT and Global studies, are significantly affected by varying ocean and sediments conductivity. Incorporating this information in a model prior to inversion helps avoid artifacts and improve data fit. The atlas is openly available along with a concise and easy to use Python toolbox.
infoBalloons: an Italian High School educational self-made budget friendly STEM experience with hot air/stratospheric balloons
Authors: Tealdi Paolo , Innocenti Fabrizio , Aimo Giovanni (John)
Published: March 2021

infoBalloons 2.0 is a selected Sounding Balloon (SB) Experiments in the 2nd HEMERA Call for Proposals (HEMERA H2020. This project has received funding from the European Union's Horizon 2020 research and Innovation programme under grant agreement No 730970).

This is a solution (self-made app/software and budget friendly IoT sensors and TC/TM communication link) to collect and then analyze data regarding atmospheric sounding, flight info/data and LPWAN (Low Power Wide Area Network) performances during a stratospheric balloon flight. Optional also to take POV photos/video of the flight.

infoBalloons 2.0 is the natural evolution of infoBalloons. The old 1.0 system reports a bunch of environmental data to an Android self-made app (available on Google Play for free) being carried in the hot air balloons using budget friendly industrial IoT sensors called Blebricks. IoT sensors communicate with the Android app installed inside the pilote’s smartphone using Bluetooth protocol and then the app partially elaborates the data and transmits them into the cloud (iSENSE platform) using a data (3G/4G) connection. infoBalloons was used several times during test flights and also for example during the International Hot Air Balloons Meeting in Mondovì in January 2019; it was developed by a group of Scientific High School students (I.I.S. “Cigna-Baruffi-Garelli” – Mondovì [Italy]) with the technical support of John Aimo Balloons - [Italy] (hot air balloons flights), Bleb Technology - [Italy] (Blebricks, the budget friendly industrial IoT sensors), iSENSE team (iSENSE is a web system for sharing and visualizing scientific data, based at the Engaging Computing Group at the University of Massachusetts Lowell [USA]) and MIT App Inventor team (CSAIL - Massachusetts Institute of Technology [USA]). The work was also presented in the Poster Session at last MIT App Inventor Summit 2019 in Cambridge, MA – USA.
Coriolis force influence on the AKA effect
Authors: Rutkevich Peter , Golitsyn Georgy , Tur Anatoly
Published: March 2021

Large-scale instability in incompressible fluid driven by the so called Anisotropic Kinetic Alpha (AKA) effect satisfying the incompressible Navier-Stokes equation with Coriolis force is considered. The external force is periodic; this allows applying an unusual for turbulence calculations mathematical method developed by Frisch et al [1]. The method provides the orders for nonlinear equations and obtaining large scale equations from the corresponding secular relations that appear at different orders of expansions. This method allows obtaining not only corrections to the basic solutions of the linear problem but also provides the large-scale solution of the nonlinear equations with the amplitude exceeding that of the basic solution. The fluid velocity is obtained by numerical integration of the large-scale equations. The solution without the Coriolis force leads to constant velocities at the steady-state, which agrees with the full solution of the Navier-Stokes equation reported previously. The time-invariant solution contains three families of solutions, however, only one of these families contains stable solutions. The final values of the steady-state fluid velocity are determined by the initial conditions. After account of the Coriolis force the solutions become periodic in time and the family of solutions collapses to a unique solution. On the other hand, even with the Coriolis force the fluid motion remains two-dimensional in space and depends on a single spatial variable. The latter fact limits the scope of the AKA method to applications with pronounced 2D nature. In application to 3D models the method must be used with caution.

[1] U. Frisch, Z.S. She and P. L. Sulem, “Large-Scale Flow Driven by the Anisotropic Kinetic Alpha Effect,” Physica D, Vol. 28, No. 3, 1987, pp. 382-392.
Analysis of non-double-couple source mechanisms in an area of induced seismicity, West Texas (USA).
Authors: Alexandros Savvaidis , Pamela Roselli
Published: March 2021

In the scope to investigate the possible interactions between injected fluids, subsurface geology, stress field and triggering earthquakes, we investigate seismic source parameters related to the seismicity in West Texas (USA). The analysis of seismic moment tensor is an excellent tool to understand earthquake source process kinematics; moreover, changes in the fluid volume during faulting leads to existence of non-double-couple (NDC) components (Frohlich, 1994; Julian et al., 1998; Miller et al., 1998). The NDC percentage in the source constitutes the sum of absolute ISO and CLVD components so that %NDC= % ISO + %CLVD and %ISO+%CLVD+%DC=100%. It is currently known that the presence of NDC implies more complex sources (mixed shear-tensile earthquakes) correlated to fluid injections, geothermal systems and volcano-seismology where induced and triggered seismicity is observed.

With this hypothesis, we analyze the micro-earthquakes (M <2 .7) recorded by the Texas Seismological Network (TexNet) and a temporary network constituted by 40 seismic stations (equipped by either broadband or 3 component geophones). Our study area is characterized by Northwest-Southeast faults that follow the local stress/field (SHmax) and the geological characteristic of the shallow basin structure of the study area. After a selection based on signal-to-noise ratio, we filter (1-50 Hz) the seismograms and estimate P-wave pulse polarities and the first P-wave ground displacement pulse in time domain. Then, we perform the full moment tensor analysis by using hybridMT technique (Andersen, 2001; Kwiatek et al., 2016) with a detailed 1D velocity model. The key parameter is the polarity/area of the first P-wave ground displacement pulse in time domain. Uncertainties of estimated moment tensors are expressed by normalized root-mean-square (RMS errors) between theoretical and estimated amplitudes (Vavricuk et al., 2014). We also evaluate the quality of the seismic moment tensors by bootstrap and resampling. In our preliminary results we obtain NDC percentage (in terms of %ISO and %CLVD components), Mw, seismic moment, P, T and B axes orientation for each source inverted.
Satellite remote sensing of the Oka-Volga confluence zone during the ice melting
Authors: Danilicheva Olga , Ermakov Stanislav , Kapustin Ivan
Published: March 2021

The river confluence is one of the most complex processes in river morphology, which plays an important role in riverbed deformation, mixing processes, pollution transport, etc. The area of river confluence can be often visually observed as the relatively thin transition region or mixing zone (MZ) separating two parallel weakly mixing flows. The mixing zone characteristics, in particular width, are important indicators of the turbulent mixing intensity and momentum and substance exchange between two flows, therefore, understanding the physical mechanisms affected on the mixing zone formation and manifestation is an important task in ecological remote monitoring. A typical example of a river confluence is the merging of the Volga and Oka rivers (Russia). In this work satellite radar and optical images of the Oka -Volga MZ during the active ice cover melting were analyzed. The mixing zone of rivers as the formation of wet snow at the initial stages of melting, which further contributes to the formation of open water patches in the area of rivers confluence zone is shown. Such manifestation of the mixing zone can be presumably associated with factories / thermal power plants emissions and turbulent mixing of river flows. An increase of the radar signal backscattering of wet snow was observed, and it can be associated with the predominance of surface scattering (an increase of affection of surface roughness) with an increase of snow and ice cover moisture. In conditions of positive average daily temperatures, intense ice melting led to the appearance of open water patches, which were partially covered with fragmented ice. Although the wind velocity during the observation period was about 3-5 m/s, which significantly exceeds the threshold of wind waves excitation, the latter, was rather weak, in particular, due to the wind wave damping on the water covered with the floes. This led to the manifestation of the MZ as an extended dark band, and also presumably caused weak radar backscattering after the ice opening of the Volga part.

The research was funded by the Russian Foundation for Basic Research (Projects RFBR № 18-45-520004 and № 20-05-00561)
Dating polymetamorphism using titanite: Linking trace elements, textures, and ages
Authors: Walters Jesse , Cruz-Uribe Alicia , Song Won Joon , Stone Joshua , Brooks Hanna , Biela Kimberley
Published: March 2021

Here we present titanite U-Pb dates from two banded calc silicate gneisses (SSP18-1A and 1B) from western Maine. Mineral textures and compositions display multiple phases of metamorphism. The peak lower granulite facies assemblage is Di + Kfs + Pl + Ttn, with little to no calcite present. Late Czo + Tr replaces Di + Pl, suggesting an influx of XH2O > 0.90 fluids. Nearby metapelites show the transition from sillimanite-bearing to muscovite-bearing assemblages, indicating that fluid infiltration may be widespread. Compositional maps of clinopyroxene in SSP18-1B show fracturing and rehealing of early Fe-rich diopside with late Mg-rich diopside. Both samples exhibit overprinting of An-rich plagioclase by increasingly Ab-rich plagioclase. Titanite grains in both samples exhibit BSE textures and compositional variation consistent with multiple phases of growth and dissolution-reprecipitation reactions.

Titanite trace element and U-Pb data were collected by LA-ICP-MS at the University of Maine using an ESI NWR193UC excimer laser ablation system coupled to an Agilent 8900 ICP-MS. Single spot ages range from 280 to 400 Ma with 12-20 Ma propagated 2SE. Four composition-date domains are identified in SSP18-1B: A. 400 ± 8 Ma (dark BSE cores), B. 372 ± 4 Ma (bright BSE cores), C. 342 ± 6 Ma (bright BSE cores, no Eu anomaly), and D. 302 ± 3 Ma (dark BSE rims, low LREE). Titanite Fe and Y concentrations increase with decreasing date, whereas Sr concentrations decrease. In clinopyroxene, Fe and Y decrease between high Fe-diopside and late Mg-diopside, placing the fracturing and rehealing events between 400 and 372 Ma. Strontium concentrations in titanite decrease between subsequent generations of plagioclase, diopside, and titanite, suggesting a continual fractionation of Sr from the reactive bulk composition. Low LREE in ca. 300 Ma titanite domains in both samples are consistent with the formation of texturally late allanite and clinozoisite, thus constraining the timing of the high XH2O fluid infiltration event. Zr-in-titanite temperatures for rims in the quartz-bearing SSP18-1B give a weighted mean T of 764 °C at 4.5 GPa, consistent with the muscovite-absent sillimanite-bearing assemblage in garnet cores from metapelite samples. However, the 100-150 °C lower Grt-Bt temperatures for metapelites are not consistent with peak metamorphic phase equilibria. Our data demonstrate the utility of linking titanite textures and trace element concentrations with those of other minerals to reveal past metamorphic and deformational events. Additionally, we show that titanite may reliably preserve U and Pb isotopic ratios, trace elements, and textures over subsequent high-T metamorphic events.
Simulating and visualising the continental water cycle with CWatM, the open-source Community Water Model
Authors: Smilovic Mikhail , Guillaumot Luca , de Bruijn Jens , Burek Peter
Published: March 2021

The process-based hydrological model Community Water Model (CWatM) is presented simulating the water cycle from regional to global and with different resolutions. Human influences within the water cycle have been further integrated and recent developments to improve the representation of water management and distribution, reservoirs, crops, and groundwater processes are demonstrated. “Water circles" are introduced along with a dashboard to visualise the components of the water cycle and evaluate water availability in the context of water demands. The dashboard along with a set of tutorials and testing suite continue to support the accessibility of model adoption and open-source code development.
“Stakeholder engagement strategy: monitoring and evaluate the impact in OPERANDUM project”
Authors: Carlone Teresa , Mannocchi Matteo , Bucchignani Edoardo , Ruggeri Paolo , Leo Laura Sandra , Pulvirenti Beatrice , Polderman Annemarie , Panga Depy , Soini Katriina , Amirzada Zahra
Published: March 2021

The OPERANDUM project is designed to address major hydro-meteorological risks through the deployment and assessment of Nature-Based Solution (NBS). The project pursues a co-creation approach and sets up 7 Open Air Laboratories (OAL) in which a user-centric method, characterized by the active participation of the stakeholders, is promoted. Stakeholder engagement in co-designing, co-developing, and co-deploying NBS is becoming a prominent practice in environmental projects and a crucial part of the process is monitoring and impact evaluation of the engagement strategy and actions. Monitoring aims at providing information about the stakeholder engagement processes throughout the project and should not be seen as a separate part of the stakeholder engagement processes or an aim in itself but as a continuous and integral element of the co-creation process. The poster shows the results of preliminary empirical research conducted among the OALs in order to propose some key indicators useful to evaluate the process and the impact generated by the OPERANDUM co-creative approach.  Starting from a theoretical framework, the research selected and discussed some crucial indicators in order to propose an action plan for the monitoring and impact evaluation of OPERANDUM strategy to involve and support the participation of stakeholders, with a specific focus on the tools used so far and those that are in the pilot phases (i.e Stakeholder Forum experimented in OAL Italy). Both qualitative and quantitative methods have been included in the evaluation for the engagement strategy outcome of the projects to be fully understood and, not secondarily, to identify a sustainability strategy beyond the conclusion of OPERANDUM to reinforce the social acceptance, the shared knowledge, and the upscaling of NBS at local, national and global level.
Evaluation of the spatial distribution of a stochastically reconstructed ensemble of precipitation fields using RMWSPy
Authors: Haese Barbara , Blettner Nico , Hörning Sebastian , Linder Marco , Chwala Christian , Kunstmann Harald
Published: March 2021

Precipitation is one of the most essential variables within the hydrological system, and accordingly one of the main drivers for terrestrial hydrological processes. The quality of many hydrological applications such as climate prediction, water resource management, and flood forecasting, depends on the correct reproduction of its spatiotemporal distribution. Not only are there a variety of methods for reconstructing precipitation maps, but the reconstruction can also be based on different observation types or its combinations. In our approach we use rain gauge observations and path-averaged rain rates, derived from Commercial Microwave Link (CML) attenuations, as observations. Using these two observation types we apply Random Mixing Whittaker-Shannon (RMWSPy) to stochastically simulate precipitation fields. 

The algorithm generates precipitation fields as a linear combination of unconditional spatial random fields, where the spatial dependence structure is described by copulas. The weights of the linear combination are optimized in such a way that the precipitation observations themselves as well as their spatial structure are reproduced. Using RMWSPy allows to simulate a precipitation field ensemble of any size, where each ensemble member is in concordance with the underlying observations. 

Here, we apply RMWSPy to the whole of Germany and various catchments of different sizes, covering cases with different amount of available observations and different orographic complexity. The resulting ensembles of precipitation fields are evaluated regarding the quality of the reproduced spatial distribution of the precipitation and its pattern. We show that the reconstructed precipitation fields reproduce the observed spatiotemporal distribution in a quality that is comparable to the gauge-adjusted radar product RADOLAN-RW provided by the German Weather Service (DWD).
A Pseudo-3D Vs Velocity Model of Ischia Island (Italy) by HVSR spectral ratio inversion
Authors: Manzo Roberto , Nardone Lucia , Gaudiosi Guido , Martino Claudio , Galluzzo Danilo , Bianco Francesca , Di Maio Rosa
Published: March 2021

Following the MD4.0 (Mw3.9) earthquake of August 21 2017 which occurred on the Ischia island (Naples, southern Italy), the local monitoring seismic network was significantly improved in terms of both number of stations and instrumentation performance. Due to the considerable amount of collected data, in particular of seismic noise recorded at broadband stations, some efforts have been addressed in particular to the definition of a 1D average velocity model effective for the whole island. This is an important scientific step because, in complex volcanic areas, the use of reliable velocity models is essential for an accurate localization of local earthquakes. In this work, the main target is to retrieve a pseudo-3D velocity model of the Ischia island. Specifically, we inverted H/V curves and frequency peaks evaluated at about twenty sites to obtain a velocity profile for each of the investigated measurement points. Taking into account that the H/V frequency peak depends on both velocity and thickness of layers, for each site we applied an inversion process fixing the velocities and modifying the thicknesses in order to obtain the corresponding 1D velocity models. We are quite enough confident about the robustness of models, since during the inversion process, we achieved a good convergence towards the best-fit solutions. Then, a pseudo-3D velocity model was obtained by contouring the 1D models of each station site to highlight possible lateral variations of the layer thicknesses and to reconstruct the morphology of the deeper interface characterized by a high impedance contrast. A good correspondence between the pseudo-3D model and the geological features of the island was observed, especially in the northern sector where most of the stations is installed. In particular, the top of the high-impedance contrast interface appears deeper in the northern coastal areas and shallower in the central sector. This is in agreement with the structural setting of the island likely due to the resurgence of Mount Epomeo.

 