bluuebunny/crossref_metadata_2025 huggingface dataset:
The effects of Soil-Improving-Cropping-Systems (SICS) across Europe: a simulation study
Authors: Baartman Jantiene , Nunes Joao Pedro , Fleskens Luuk , Vanhout Roel , Gai Lingtong , Van Delden Hedwig
Published: March 2022

One of the strongest challenges for European agriculture is to simultaneously reduce its negative environmental impact and at the same time, remain competitive. A key aspect of the environmental impact is the ongoing soil degradation. Within the Soil Care project, sustainable agricultural practices were investigated that could improve soil quality, termed soil improving cropping systems (SICS); four plausible scenarios were developed with different levels of SICS uptake. In this study we aimed to evaluate how such SICS, through the different scenarios, impact crop yield, soil organic carbon content and land degradation (specifically erosion and soil water dynamics) across Europe, through the application of the PESERA and dyna-QUEFTS models. The Pan-European Soil Erosion Risk Assessment (PESERA) model simulates biophysical processes including above-ground biomass production, soil erosion risk, soil water deficit and soil humus content and was adapted and calibrated for Europe. The dyna-QUEFTS model calculates nutrient limitations and was used to calculate crop yields using PESERA output information. All four scenarios were run from current (2020) until 2050 and for two climate trajectories. Results indicate that the ‘Caring and Sharing’ scenario likely provides the best sustainability impacts (i.e. stable or increased SOC contents and reduced erosion) due to widespread uptake of SICS, compared to the ‘Race to the Bottom’ scenario, in which no SICS were taken up, although regional differences can be seen from the spatially explicit maps that the modelling produces. While, by necessity, the models are a simplification of the reality and assumptions and input data quality affect the results, a comparative analysis of the scenarios and their likely effect can still be made and will be helpful for agricultural policy development across Europe. In addition, the modelling tool provides the opportunity to further analyze which SICS are effective where and to explore the impacts of SICS implementation.
The Upper Palaeozoic Vein Hosted Copper Deposits of the Allihies Mining Area, Southwest Ireland – A New Structural and Chronological Evaluation
Authors: Meere Patrick , Lang Juergen , Unitt Richard
Published: March 2022

This study focusses on the vein-hosted copper sulphide deposits in the Upper Palaeozoic Munster and South Munster Basins of southwest Ireland. Detailed mapping of the Allihies mine area (Beara Peninsula), have led to a new interpretation of the timing and development of mineralised quartz veins. Macro- and microstructural investigations reveal that the copper sulphide-bearing, mainly E-W striking quartz veins are directly related to early extensional, basinal normal faults. Molybdenite Re-Os dating of the main-stage Cu lode yield ages from 367.3 ± 5.5 to 366.4 ± 1.9 Ma. Bi-phase (LV) aqueous fluid inclusions associated with the mineralised quartz veins range from moderate salinity with high homogenisation temperatures (>3.2 wt% NaClequiv, Th < 314°C) to high salinities with very low homogenisation temperatures (<28.5 wt% NaClequiv, Th >74°C) The extensional faults and associated quartz veins experienced subsequent late Carboniferous Variscan deformation, including cleavage development, sinistral SW-NE strike slip faulting, cataclastic deformation and recrystallization of vein fills. Later fluids with low to moderate salinities and Th values of about 200°C were trapped in syn-Variscan quartz-chlorite saddle reefs and en echelon tension gash arrays in semi brittle shear zones. The new timing of Cu mineralisation in SW Ireland has major implications for its relationship to the base metal deposits of the Irish Midlands.
Wave-eddy interactions in the Gulf of Lion: Bridging ocean general circulation models and process ocean simulations
Authors: Claret Mariona , Lelong M.-Pascale , Winters Kraig B. , Ourmières Yann
Published: March 2022

Near-inertial waves (NIWs) are of major relevance to the global ocean circulation as they inject wind energy from the surface to the ocean interior and represent a primary source  of energy to the internal wave continuum. Eddies and fronts play a significant role in the downward penetration of NIW energy (from generation to propagation) and subsurface dissipation. Much of our understanding of NIW interactions with submeso- and mesoscale flows comes from limited observations as well as idealized theoretical and numerical processes, but these do not typically consider the presence of temporally evolving larger-scale flows. On the other hand, more realistic and time-evolving eddy fields from submesoscale-resolving Ocean General Circulation Models (OGCMs) forced with winds show truncated spectra at the subsurface due to the lack of vertical resolution -the subgrid vertical scale is 1-2 orders of magnitude larger than the scale at which dissipation occurs.  Since OGCMs are indeed very attractive tools to quantify global-regional impacts of small-scale phenomena, we propose to gain understanding of their biases in terms of wave-eddy interactions by using a novel approach.

This approach consists of nesting a non-hydrostatic Boussinesq model (Flow_Solve) into an OGCM configuration (NEMO-GLAZUR64) for the Gulf of Lion with O(1 km) horizontal and  O(30 m) vertical resolution. Preliminary analysis of NEMO-GLAZUR64 output reveals a highly energetic NIW field with intriguing distribution patterns relative to the eddies. We zoom into these patterns by following eddies with our nesting approach. The Boussinesq model provides a magnifying glass into dynamical processes that are either parameterized or fully unresolved in the OGCM. Wave energy budgets inferred from high-resolution process studies with Flow_Solve and NEMO-GLAZUR64 are then compared in order to better constrain model uncertainty in OGCMs due to NIW dynamics. 
Estimation of Lunar Ephemeris from Lunar Laser Ranging
Authors: Singh Vishwa Vijay , Biskupek Liliane , Mueller Juergen , Zhang Mingyue
Published: March 2022

Lunar Laser Ranging (LLR) has been measuring the distance between the Earth and the Moon since 1969, where the measurements are provided by the observatories as Normal Points (NPs). The Institute of Geodesy (IfE) LLR model has (as of April 2021) 28093 NPs. Using the LLR observation equation, the LLR residuals (difference of observed and calculated values of the light travel time) are obtained for each NP. The LLR analysis procedure is an iteration of the calculation of ephemeris of the solar system followed by the calculation of residuals and the estimation of parameters using a Least-Squares Adjustment (LSA). The initial orbit of the Moon (Euler angles and angular velocity of the lunar mantle, Euler angles of the lunar core, and the position and the velocity of the selenocenter), amongst many other parameters, is estimated from the LSA. In our previous standard calculation, the initial orbit of the Moon was estimated for June 28, 1969 and ephemeris was calculated from this time until June 2022. In this study, we estimate the initial orbit of the Moon for Jan 1, 2000 to be able to benefit from the higher accuracy of the NPs over the timespan of LLR. The ephemeris is then calculated in forward and backward directions (until June 2022 and June 1969). When comparing the uncertainty obtained from a LSA of this study with the previous standard calculation, preliminary results show an improvement of over 50% in the initial position and the initial velocity of the Moon, a deterioration of about 20% in the Euler angles of the mantle and the core, and an improvement of over 15% in the angular velocity of the mantle. The changed analysis procedure will allow to compute a more accurate ephemeris for the upcoming years benefitting future lunar science. Recent results will be presented and major changes would be discussed.

Acknowledgement. This research was funded by Deutsche Forschungsgemeinschaft (DFG) under Germany’s Excellence Strategy EXC 2123 QuantumFrontiers-390837967.
Cracking induced by dislocation creep in pure quartz shear bands of granitoids
Authors: Précigout Jacques , Ledoux Estelle , Arbaret Laurent
Published: March 2022

The production of micro-pores during viscous creep is a driving mechanism for fluid circulation in deep environments. However, strain-induced cracking in nature is nowadays attributed to grain boundary sliding (GBS), restricting this process to fine-grained ductile shear zones where rocks deform by diffusion creep. Here we give natural evidence of micro-cracking induced by dislocation creep, which is by far the dominant deformation mechanism in lithospheric rocks. Focusing on pure quartz shear bands across the Naxos western granite (Aegean Sea, Greece), we first document sub-micron pores that arise at grain and sub-grain boundaries. Their shape and location emphasize sub-grain rotation as a source of cracking. We then confirm that quartz is dominated by dislocation creep with evidence of a moderate to strong lattice preferred orientation (LPO) and many sub-grain boundaries, including at the margin of the pluton where the brittle/ductile transition was reached. These features coincide with (1) quartz grains located as inclusion into quartz porphyroclasts and (2) a dependency of the LPO strength on grain size. Our findings suggest that creeping cavities act as pumping sites for fluid to penetrate the crystal lattice and nucleate randomly oriented grains along sub-grain boundaries, accounting for (1) shear localization by enhancing hydrolytic weakening and (2) rock embrittlement through growth and interlinkage of cavities where phase nucleation is limited.
Arctic pacing of North Atlantic climate variability through freshwater exports
Authors: Oltmanns Marilena , Moat Ben
Published: March 2022

Freshwater plays a key role in the Arctic - North Atlantic climate system, linking ice, ocean and atmospheric dynamics. In particular, large freshwater releases into the subpolar region drive extreme cold anomalies, create sharp sea surface temperature fronts, destabilise the overlying atmosphere, and trigger shifts in major ocean currents. Considering the expected increased freshwater fluxes in future due to more melt, it is critical to understand the resulting climate feedbacks.

Combining observations and models, we present evidence that past changes in Arctic freshwater outflow paced transitions between North Atlantic cold and warm anomalies. This circulation-driven freshwater cycle explained over 50% of the sea surface temperature variability in the subpolar North Atlantic and was particularly pronounced on decadal timescales. However, new findings indicate that the recent freshwater input due to more melting has increased the amplitude and frequency of freshwater variations in the North Atlantic, leading to a shift of power in the North Atlantic climate variability from decadal to interannual timescales. In addition, the interference of the circulation-driven freshwater cycle by melting has contributed to the storage of freshwater in the Arctic Ocean, where it now poses the possible risk of rapid climate change if the freshwater were released. In light of newly identified, Arctic feedbacks to melt-driven freshwater events in the North Atlantic, we suggest that an Arctic freshwater release is becoming increasingly likely.
Time averaging, stratigraphic disorder and geochemical proxy records: cautionary tale from the Holocene stratigraphic record of the Adriatic Sea
Authors: Nohl Theresa , Nawrot Rafał , Tomašových Adam , Zuschin Martin
Published: March 2022

Variations in sediment supply are known to potentially alter the concentration of fossils or to mix up components of different environments or stratigraphic ages. The combination of shifts in sediment supply rates, sediment transport, bioturbation, erosion, and accommodation space can, controlled by the eustatic sea-level, lead to systematic changes in the extend of time averaging and consequently temporal resolution of the fossil record. The effect of this bias on fossil occurrence patterns is well studied, though less emphasis has been paid to its potential influence on the observed record of geochemical proxies, which are extracted from these fossils. To assess this potential bias in geochemical proxies we analysed δ13C and δ18O values from 14C- and amino-acid dated Holocene Corbula gibba shells from the Northern Adriatic Sea, covering the transgression and sea level highstand since the last deglaciation. As the fossil assemblages in transgressive deposits are typically more time-averaged compared to highstand strata, and thus capture larger absolute age span,  the range of δ13C and δ18O values should be higher in the transgressive core sections. However, our initial results suggest that while the age range indeed increases with sediment depth, the carbon and oxygen isotopic ranges decrease, with a few exceptions. This could be caused by higher variation or higher pace of environmental change during deposition of highstand strata, or by increased homogenisation due to the increased time of exposition to diagenetic fluids with sediment depth.
Data assimilation and nowcasting of severe weather for air traffic management purposes
Authors: Mazzarella Vincenzo , Milelli Massimo , Lagasio Martina , Poletti Laura , Biondi Riccardo , Realini Eugenio , Federico Stefano , Torcasio Rosa Claudio , Kerschbaum Markus , Llasat Maria Carmen , Rigo Tomeu , Esbrí Laura , Temme Marco-Michael , Gluchshenko Olga , Temme Annette , Nöhren Lennard , Parodi Antonio
Published: March 2022

One of the main challenges for meteorologists is to improve the prediction of events that develop on small spatial and temporal scales, having important repercussions in air traffic activities. In this regard, the H2020 SESAR Satellite-borne and IN-situ Observations to Predict The Initiation of Convection for ATM (SINOPTICA) project, aims to demonstrate that the prediction of severe weather events with high spatial and temporal resolution, can benefit the ATM and aviation safety. SINOPTICA assimilates non-conventional observations such as Global Navigation Satellite System (GNSS), weather radar, and lightning data into numerical weather prediction model with a nowcasting technique called PHAse-diffusion model for STochastic nowcasting (PHAST) allowing to predict the highly localized convective events triggering in the vicinity of airports.

As part of the project, three severe weather events were identified on the Italian territory which caused the closure of the airports, delays on arrivals and departures, and numerous diversions. The results of the numerical simulations, carried out with the Weather Research and Forecasting (WRF) and nowcasting technique PHAST, were integrated into the Arrival Manager 4D-CARMA (4-Dimensional Cooperative Arrival Manager), an adaptive air traffic sequencing and management system for controllers, which generates and optimizes 4D trajectories to avoid areas affected by adverse phenomena and, under certain circumstances, reducing controllers’ and pilots’ workload. The results show that the nowcasting technique is able to predict the convective cells in shape, intensity and time. In addition, the assimilation of lightning and GNSS data improves the forecast accuracy of the above-mentioned events in line with expectations and ATM needs.
 Fully coupled subsurface-land surface hydrological models: A scaling approach to improve subsurface storage predictions
Authors: Soltani Samira Sadat , Fahs Marwan , Al Bitar Ahmad , Ataie-Ashtiani Behzad
Published: March 2022

The flow conditions (e.g., river network) for rivers and open channels are often forced into hydrogeological models that use a constant horizontal grid resolution without correction for grid mismatching. As a result, the flow velocity will be significantly underestimated if the width of rivers is substantially narrower than the grid size of these models. Furthermore, the exchange between the river and the subsurface is overestimated, resulting in an erroneously large vertical exchange.

In response to this challenge, in this work, the subscale channel flow is approximated in the kinematic wave equation by a scaled roughness coefficient. A relationship between grid cell size and river width is used for this purpose, which follows a simplified modification of the Manning-Strickler equation. In addition, the exchange between the subsurface and the river, as well as the rate of ex- and in-filtration, are scaled across river beds based on grid resolution. As a result, even though the grid size is relatively large, the exchange rates are corrected across river beds. The effectiveness of the scaling of river parametrization is validated against groundwater gauges and remote sensing-based surface soil moisture in a fully coupled subsurface-land surface ParFlow-CLM at a spatial resolution of 0.055° (~6 km) over the Upper Rhine Basin. The validity of the results is examined through an innovative application of the First Order Reliability Method (FORM) for the time period 2012-2014. Results indicate that the scaling approach improves the estimates of soil moisture, particularly in the summer and autumn seasons when cross-validated with independent CCI-SM observations. This improvement is achieved (SM RMSE reduction from 0.03 to 0.005) due to the effective impacts of the scaling river parametrization on SM estimation. FORM results show that the accuracy of ParFlow-CLM soil moisture simulations by using scaling approach is more than 95, 89, 85 and 92 percent for Autumn, Winter, April and Summer, respectively. The scaling river parametrization also shows overall improvements in groundwater level estimation, particularly over the central and northern regions where the groundwater level is shallow.
Impact of thermal imbalanced radiation forces on GNSS satellite orbits
Authors: Duan Bingbing , Hugentobler Urs
Published: March 2022

An accurate model of all the forces acting on a satellite is an essential precondition of achieving high orbit accuracy. Solar radiation pressure (SRP), the largest non-gravitational perturbation for GNSS satellites is typically modeled by an empirical model (i.e., Empirical CODE Orbit Model, ECOM/ECOM2). If satellite metadata information is available, an analytical box-wing model can be formed to reinforce the ECOM models. However, the current GNSS satellite orbits show notable degradation during eclipse seasons in particular for long-arc solutions and orbit predictions. The reason is proven to be mostly due to the ignoring of the thermal imbalanced forces (i.e., radiator emission and thermal radiation of solar panels). The ECOM parameters can compensate these thermal radiation forces fairly well outside eclipse seasons, while this is not true when satellites are inside eclipse seasons, because the Earth’s shadowing of a satellite in orbit causes periodic changes of the thermal environment. On one hand, these thermal imbalanced forces contribute also inside the shadow while inside the shadow all the ECOM parameters are deactivated. On the other hand, satellite attitude could be far from the nominal inside the shadow, making that these thermal imbalanced forces cannot be well absorbed by the ECOM parameters. To capture these thermal forces, we set up physical thermal force models for each Block type of GNSS satellites. In the absence of published thermal properties, we estimate necessary thermal modeling parameters using tracking data over long time period. With the use of the physical thermal force models, satellite orbits inside eclipse seasons are greatly improved. For instance, orbit misclosures are improved by a factor of two for BDS-3 and Galileo satellites when using the 5-parameter ECOM model.
Active Control of the Radiation Belt Particle Populations with Ionospheric Amplification of VLF Waves
Authors: Bernhardt Paul , Hua Man , Bortnik Jacob , Ma Quanli , Verronen Pekka , McCarthy Michael , Golkowski Mark , Cohen Morris , Howarth Andrew , James Gordon , Meredith Nigel
Published: March 2022

Ground-based VLF transmitters located around the world generate signals that leak through the bottom side of the ionosphere in the form of whistler mode waves.  Wave and particle measurements on satellites have observed that these man-made VLF waves can be strong enough to scatter trapped energetic electrons into low pitch angle orbits, causing loss by absorption in the lower atmosphere.  This precipitation loss process is greatly enhanced by intentional amplification of the whistler waves in the ionosphere using a newly discovered process called Rocket Exhaust Driven Amplification (REDA).  Satellite measurements of REDA have shown between 30 and 50 dB intensification of VLF waves in space using a 60-second burn of the 150 g/s thruster on the Cygnus satellite that services the International Space Station (ISS) [Bernhardt et al. 2021; Bernhardt 2021].  This controlled amplification process is adequate to deplete the energetic particle population in the radiation belts in a few minutes rather than the multi-day period it would take naturally.  Numerical simulations of the pitch angle diffusion for radiation belt particles use the UCLA quasi-linear Fokker Planck model (QLFP) to assess the impact of REDA on radiation belt remediation (RBR) of newly injected energetic electrons [Bernhardt et al., 2022].  The simulated precipitation fluxes of energetic electrons are applied to models of D-region electron density and bremsstrahlung x-rays for predictions of the modified environment that can be observed with satellite and ground-based sensors.   

References:

Bernhardt, P.A., et al., Strong Amplification of ELF/VLF Signals in Space Using Neutral Gas Injections from a Satellite Rocket Engine (2021), Radio Science, 56(2), e2020RS007207, https://doi.org/10.1029/ 2020RS007207.

Bernhardt, P.A., The Whistler Traveling Wave Parametric Amplifier (WTWPA) Driven by an Ion Ring-Beam Distribution from a Neutral Gas Injection in Space Plasmas (2021), IEEE Transactions on Plasma Science. 49, 6, 1983-1996, DOI: 10.1109/TPS.2021.3079130.

Bernhardt, P.A., et al., Active Precipitation of Radiation Belt Electrons using Rocket Exhaust Driven Amplification (REDA) of Man-Made Whistlers, Submitted to the Journal of Geophysical Research, 2022.
Bridging linear state estimation and machine learning
Authors: Chipilski Hristo
Published: March 2022

Recent years have seen active efforts within the geophysical community to combine traditional Data Assimilation (DA) methods with emerging Machine Learning (ML) techniques. However, most of this past theoretical work has been centered on variational DA approaches due to their similarity with ML in terms of how the underlying optimization problem is formulated and solved. Here I will present a new and completely general nonlinear estimation theory that retains the flexibility of advanced sampling-based methods (e.g., the particle filter) and the analytical tractability of linear estimation algorithms (e.g., the ensemble Kalman filter). In particular, an alternative state space model will be constructed whose filtering and smoothing distributions remain closed under a wide class of nonlinear functions. Since these nonlinear functions are only required to be bijective and continuously differentiable, the new estimation theory serves an ideal framework for rigorously incorporating invertible neural networks in the DA design. There are two additional properties which make the proposed framework especially appealing. First, linear estimation results follow immediately upon substituting the invertible neural networks with the identity transformation. Second, the prior and posterior belong to the same distribution family, which implies that the correlation structure and the corresponding dynamical balances in the model state are preserved following the analysis step. During the upcoming EGU meeting, I will discuss the motivation behind the new estimation framework, place it in the context of existing nonlinear DA techniques and demonstrate some of its benefits through idealized numerical examples.
Characteristics of Differential Lunar Laser Ranging
Authors: Zhang Mingyue , Müller Jürgen , Biskupek Liliane , Singh Vishwa Vijay
Published: March 2022

With more than 50 years of distance measurements for tracking the Moon from Earth by using laser pulses, Lunar Laser Ranging (LLR) plays an important role in many research fields, e.g., relativity tests and lunar interior modelling. However, due to the limited LLR accuracy, mainly caused by the Earth’s atmosphere, some Earth-Moon parameters can only be determined with poor quality and certain details of the lunar interior cannot be assessed. A new laser station of JPL will enable a new technique of lunar tracking: Differential Lunar Laser Ranging (DLLR). The DLLR observation is the difference of any two consecutive ranges obtained by fast switching of a station between two or more reflectors. Because of the large reduction of the Earth’s atmospheric error, a big improvement of the observation accuracy of about 30 µm can potentially be obtained. Therefore, DLLR will provide an excellent chance to estimate various parameters with higher accuracies and to achieve a better understanding of the lunar interior. It is also expected to be beneficial for relativity tests, e.g., related to the equivalence principle (EP). For the comparison of DLLR and LLR with respect to the parameter sensitivity, correlation and accuracy, simulated DLLR data has been generated having the same distribution, time span and number of observations as LLR. DLLR and LLR keep the same sensitivity for one group of parameters which include, e.g., the lunar rotation parameters. However, owing to the cancelling effect of DLLR on the station side, DLLR is less sensitive for a second group of parameters, e.g., for the station coordinates. But this can be compensated by its high measurement accuracy. The parameter accuracy of the second group estimated using DLLR remains at the same level as that obtained by LLR, while the parameter accuracy of the first group is significantly enhanced. The DLLR concept increases the correlation of reflectors and stations. Fortunately, some decorrelation can be reached by selecting a larger switching interval from one reflector to the next (e.g., 15 min instead of 1.5 min). Besides the Newtonian parameters, DLLR can also improve the estimation of the relativity parameters. In this presentation, we illustrate the basic principles of DLLR, its typical characteristics and quantify the potential improvement for the determination of various parameters of the Earth-Moon system.

Acknowledgement. This research was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy–EXC-2123 QuantumFrontiers–390837967.
Exploiting Sentinel-1 InSAR capabilities for studying the land subsidence process in an urban area 
Authors: Zuccarini Alessandro , Bayer Benedikt , Franceschini Silvia , Giacomelli Serena , Di Paola Gianluigi , Berti Matteo
Published: March 2022

Since the beginning of the 1960s, the urban area of Bologna has experienced land subsidence due to excessive groundwater withdrawals. Sinking reached its peak in the 70s of the last century when the subsidence rate attained the maximum value of about 10 cm/year, and significant damages to structures and infrastructures occurred. This process has been intensively monitored over the years, and extensive ground displacement data were collected employing various increasingly sophisticated techniques, ranging from topographic levelling to GNSS surveys and, since 1992, to satellite interferometry. Satellite data, in particular, allowed an accurate reconstruction of the land subsidence process. The available interferometric data are the results of three different SAR campaigns undertaken by local authorities in which the PSInSAR technique was adopted: 1992 – 2000 (ERS), 2002 – 2006 (ENVISAT) and 2006 – 2011 (RADARSAT). Within this work, a new InSAR survey from the free SENTINEL1 2014 – 2020 ascending and descending orbits data was undertaken by the UniBo spin-off “Fragile”. The software GMTSAR was used to process each interferogram and then a Small Baseline (SBAS) approach was followed to resolve the ground displacements over time. Great attention was paid to the choice of reference pixels on the existing buildings and structures, in order to maximise their density in the study area, and to the definition of the considered time span ranging from 6 to 365 days, allowing to analyse both quicker and slower ground movements. Compared to previous surveys, the displacement map obtained by Sentinel has a much higher spatial and temporal resolution, thus leading to a detailed interpretation of the ongoing subsidence. Results show that the displacement field well agrees with the 3D geological model of the area and that the temporal evolution of the subsidence rate nicely matches the piezometric level and groundwater pumping temporal series.
Turbulent kinetic energy dissipation rate and attendant fluxes in the western tropical Atlantic estimated from ocean glider observations
Authors: Sheehan Peter , Damerell Gillian , Leadbitter Philip , Heywood Karen , Hall Rob
Published: March 2022

Ocean gliders enable us to collect the ocean microstructure observations necessary to calculate the dissipation rate of turbulent kinetic energy, ε, on timescales of weeks to months: far longer than is normally possible using traditional ship-based platforms. Slocum gliders have previously been used to this end;  here, we report the first detailed estimates of ε calculated using observations collected by a Seaglider. Seaglider 620 was deployed in the western tropical Atlantic in early 2020 and was equipped with a FP07 fast thermistor. We use these same fast thermistor observations to calculate ε following the Thorpe scale method. We find very good agreement between estimates of ε calculated following the two methods. The Thorpe scale method yields the larger values of ε, but the average difference, less than an order of magnitude, is smaller than reported elsewhere. The spatio-temporal distribution of ε is comparable for both methods. Maximum values of ε (10-7 W kg-1) are observed in the surface mixed layer; relatively high values (10-9 W kg-1) are also observed between approximately 200 and 500 m depth. These two layers are separated by a 100 m thick layer of low ε (10-10 W kg-1), which is co-located with a high-salinity layer of Subtropical Underwater and a peak in the strength of stratification (i.e. in N2). We calculate the turbulent heat and salt fluxes associated with the observed turbulence that act to ventilate deeper layer of the ocean. Between 200 and 500 m, ε induces downward (i.e. negative) fluxes of both properties that, if typical of the annual average, would have a very small influence on the heat and salt content of the salinity-maximum layer above. We compare these turbulent fluxes with estimates of fluxes due to double diffusion, having objectively identified those regions of the water column where double diffusion is likely to occur. While the downward heat flux due to double diffusive mixing is lower than that due to mechanical mixing, the downward salt flux due to double diffusive mixing is six times greater.
The Upper Tropospheric Cyclonic Vortex Influence over Moisture Convergence and Precipitation on Brazilian Northeastern 
Authors: Lyra Matheus , Arraut Josefina , Braga Hugo
Published: March 2022

The Upper-Tropospheric Cyclonic Vortexes (UTCV) are one of the main synoptic systems responsible for rainfall production in the pre-rainy season over Northeastern Brazil (BNE). This study aims to analyze the UTCV contribution with precipitation and moisture transport convergence in the BNE, comparing it to the most important moisture recycling region in South America from 2015 to 2017 - The Amazon region (AMZ), which has the largest hydrographic basin in the world; in addition to the high importance for the moisture transport to extratropical latitudes of the continent. Furthermore, the El Niño Southern Oscillation influence on the frequency and intensity of the UTCV was also investigated. The method proposed by this study sought to calculate the average moisture convergence and precipitation through pre-established areas using virtual boxes. This comparison concerns the average intensity and total amount of moisture convergence and precipitation for the defined regions. 22 UTCV were identified during the three years of analysis, with the highest frequency in 2016, the transition year between El Niño and La Niña. Through the two boxes fixed in both study regions, it was possible to observe, on certain dates, higher concentrations of moisture convergence and precipitation in the BNE concerning AMZ. This occurred during the presence of some vortexes over the BNE, mainly in 2016, highlighting a case in January of that same year when the moisture convergence values in the BNE were more intense than the first three months in the AMZ.
Remagnetization of the Jurassic limestones in the Eastern Qiangtang Terrane (Tibetan Plateau, China): Implications for the India-Eurasia collision
Authors: Fu Qiang , Yan Maodu , J.Dekkers Mark
Published: March 2022

The Tibetan Plateau is composed of multiple accreted terranes, including (from south to north) the Tethyan Himalaya, the Lhasa, the Qiangtang, the Songpan-Ganzi and the Qaidam-Qilian terranes. The drift history of the Qiangtang Terrane and the timing of the Lhasa–Qiangtang collision are under debate. To contribute to this topic, we paleomagnetically investigate the Middle-Upper Jurassic limestones of the Yanshiping Group in the Zaduo area (32.5°N, 95.2°E), in the Eastern Qiangtang Terrane (Tibetan Plateau, China). A major challenge in paleomagnetism is the possibility of remagnetization that interferes with paleogeographic reconstructions. In this study, both thermal and alternating field demagnetizations were carried out to isolate the characteristic remanent magnetization (ChRM). Despite the positive reversals test, rock magnetic information points to a remagnetized ChRM that resides in stable single-domain (SSD) magnetite grains with cogenetic superparamagnetic (SP) particles. The co-occurreance of SSD and SP magnetites generates distinct rock-magnetic properties often refer to as the ‘remagnetized fingerprint’ in limestones. This remagnetization process is also manifested by the widespread occurrence of gypsum veinlets in the limestones. The site-mean direction of the 12 sites after tilt-correction is Ds = 30.6°, Is = 35.6°, κs = 182.9, α95 = 3.2°, corresponding to a palaeolatitude of ∼19.7°± 2.8°N for the study area. The corresponding palaeopole (59.8°N, 202.7°E with A95 = 2.8°) points to an NRM acquired after the India–Eurasia collision. The original sediments were likely anoxic because of the high organic carbon fluxes that prevailed during their deposition. After the India–Eurasia collision, it is envisaged that conditions became more oxic, giving rise to oxidation of iron sulphides to authigenic magnetite and the CRM acquisition. The Zaduo area in the Eastern Qiangtang Terrane has experienced ∼15.7° ± 3.2° (∼1740 ± 350 km) of latitudinal crustal shortening since the Eocene. In addition, the clockwise rotation responding to the India–Eurasia collision is also detected in the Zaduo area.
Parametric model for probabilistic estimation of water losses in water distribution networks: A large scale real world application to the city of Patras in western Greece
Authors: Serafeim Athanasios V. , Kokosalakis George , Deidda Roberto , Karathanasi Irene , Langousis Andreas
Published: March 2022

Abstract

Quantification of the leakage volume in pressure management areas (PMAs) is a vital task for water agencies’ financial viability. However, currently, there is no rigorous approach for their parametric modeling on the basis of networks’ specific characteristics and inlet/operating pressures. To bridge this gap, the current work focuses on the development of a probabilistic framework for minimum night flow (MNF) estimation in water distribution networks that: 1) parametrizes the MNF as a function of the network’s specific characteristics, and 2) parametrically describes water losses in individual PMAs as a function of the inlet/operating pressures. MNF estimates are obtained using the robust, non-parametric, probabilistic minimum night flow (MNF) estimation methodology developed and validated by Serafeim et al. (2021 and 2022), which allows for confidence interval estimation of the observed MNFs. The effectiveness of the developed model is tested in a large-scale real world application to the water distribution network of the city of Patras in western Greece, which serves approximately 200,000 consumers with more than 700 km of pipeline. The developed framework is validated through flow-pressure tests conducted by the Municipal Enterprise of Water Supply and Sewerage of the City of Patras to 78 PMAs of the network, indicating that the developed framework can be effectively used to improve water loss estimation and flow-pressure management in a morphologically and operationally diverse set of PMAs.

Acknowledgements

The research work was supported by the Hellenic Foundation for Research and Innovation (H.F.R.I.) under the “First Call for H.F.R.I. Research Projects to support Faculty members and Researchers and the procurement of high-cost research equipment grant” (Project Number: 1162).

 

References

Serafeim, A.V., Kokosalakis, G., Deidda, R., Karathanasi I. and Langousis A (2021) Probabilistic estimation of minimum night flow in water distribution networks: large-scale application to the city of Patras in western Greece, Stoch. Environ. Res. Risk. Assess., https://doi.org/10.1007/s00477-021-02042-9

Serafeim, A.V.; Kokosalakis, G.; Deidda, R.; Karathanasi, I.; Langousis, A. (2022) Probabilistic Minimum Night Flow Estimation in Water Distribution Networks and Comparison with the Water Balance Approach: Large-Scale Application to the City Center of Patras in Western Greece, Water, 14, 98, https://doi.org/10.3390/w14010098
Chrysophyte cysts reflect seasonal meteorological and limnological conditions: Evidence from sediment trap study in northeast Poland 
Authors: Szczerba Agnieszka , Pla-Rabes Sergi , Żarczyński Maurycy , Tylmann Wojciech
Published: March 2022

Chrysophyte cysts are considered as good environmental indicators because of short generation times, seasonal replacement, and their high sensitivity to changes in physicochemical conditions. In our study, we explored the relationship between chrysophyte cysts and changes in meteorological conditions in two lakes located in northern Poland (Łazduny and Rzęśniki). We compared samples collected in sediment traps, results of on-site monitoring of limnological and hydrochemical variables, and meteorological data. Multiple statistical analyses showed that meteorological conditions indirectly influence cyst seasonality, through changes in the mixing regimes that determine nutrient and light availability in lakes. Even though the taxonomic structure and interannual variability of chrysophyte cysts are dependent on multiple variables, air temperature proved to be the most important meteorological variable influencing cyst assemblages. Multi-level pattern analysis showed that specific cyst types were indicative of different periods of lake physical structure, thus suggesting the potential of chrysophyte cysts in paleoclimatic studies.
The ESA Virtual Space Weather Modelling Centre
Authors: Poedts Stefaan ,   VSWMC-P3 team
Published: March 2022

The ESA Virtual Space Weather Modelling Centre (VSWMC) project was defined as a long term project including different successive parts. Parts 1 and 2 were completed in the first 4-5 years and designed and developed a system that enables models and other components to be installed locally or geographically distributed and to be coupled and run remotely from the central system. A first, limited version went operational in May 2019 under the H-ESC umbrella on the ESA SSA SWE Portal. It is similar to CCMC but interactive (no runs on demand) and the models are geographically distributed and coupled over the internet.

The goal of the ESA project "Virtual Space Weather Modelling Centre - Part 3" (2019-2021) was to further develop the Virtual Space Weather Modelling Centre, building on the Part 2 prototype system and focusing on the interaction with the ESA SSA SWE system. The objectives and scope of this new project include maintaining the current operational system, the efficient integration of 11 new models and many new model couplings, including daily automated end-to-end (Sun to Earth) simulations, the further development and wider use of the coupling toolkit  and front-end GUI, making the operational system more robust and user-friendly. The VSWMC-Part 3 project finished recently.

The 11 new models that have been integrated are Wind-Predict (a global coronal model from CEA, France), the Coupled Thermosphere/Ionosphere Plasmasphere (CTIP) model, Multi-VP (another global coronal model form IRAP/CNRS, France), the BIRA Plasma sphere Model of electron density and temperatures inside and outside the plasmasphere coupled with the ionosphere (BPIM, Belgium), the SNRB  (also named SNB3GEO) model for electron fluxes at geostationary orbit (covering the GOES 15 energy channels >800keV and >2MeV) and the SNGI geomagnetic indices Kp and Dst models (University of Sheffield, UK), the SPARX Solar Energetic Particles transport model (University of Central Lancashire, UK), Spenvis DICTAT tool for s/c internal charging analysis (BISA, Belgium), the Gorgon magnetosphere model (ICL, UK), and the Drag Temperature Model (DTM) and operations-focused whole atmosphere model MCM being developed in the H2020 project SWAMI. Many new couplings have also been implemented and a dynamic coupling facility has been installed. Moreover, Daily runs are implemented of two model chains covering the whole Sun-to-Earth domain. The results of these daily runs are made available to all VSWMC users.

We will provide an overview of the state-of-the-art, including the new available model couplings and daily model chain runs, and demonstrate the system.
Sensitivity of sea ice growth to snow properties in opposing regions of the Weddell Sea in late summer
Authors: Arndt Stefanie
Published: March 2022

The sensitivity of sea ice to the contrasting seasonal and perennial snow properties in the southeastern and northwestern Weddell Sea is not yet considered in sea ice model and satellite remote sensing applications. However, the analysis of physical snowpack properties in late summer in recent years reveal a high fraction of melt-freeze forms resulting in significant higher snow densities in the northwestern than in the eastern Weddell Sea. The resulting lower thermal conductivity of the snowpack, which is only half of what has been previously assumed in models in the eastern Weddell Sea, reduces the sea ice bottom growth by 18 cm. In the northwest, however, the potentially formed snow ice thickness of 12 cm at the snow/ice interface contributes to an additional 2 cm of thermodynamic ice growth at the bottom. This emphasizes the enormous impact of unappreciated regional differences in snowpack properties on the thermodynamic ice growth.
Current and Future Flood Risk from Tropical Cyclones in Puerto Rico Under 1.5°C and 2°C Climate Change
Authors: Archer Leanne , Neal Jeffrey , Bates Paul , Vosper Emily , Sosa Jeison , Mitchell Dann
Published: March 2022

Small Island Developing States are some of the most at risk places to flooding caused by tropical cyclone rainfall. However, there is a mismatch between existing flood risk assessment in small islands, and the increasing severity of projected tropical cyclone rainfall under current and future climate change. This research aims to address this gap by presenting the first application of an event-based rainfall-driven hydrodynamic model in a small island, for the Caribbean island of Puerto Rico. Applying an event set of 59,000 synthetic hurricane rainfall events, we represent hurricane rainfall spatially (~10km) and temporally (2-hourly), estimating flood hazard and population exposure at the island scale (9,100km2) at 20m model resolution using hydrodynamic model LISFLOOD-FP. Using this event-based approach, we aim to understand: i) what are the current estimates of population exposure to flooding from hurricane rainfall in Puerto Rico; and ii) how do these risk estimates change under 1.5°C and 2°C climate scenarios. We find that current population exposure to flooding from hurricane rainfall in Puerto Rico is high (8-9.80% of the population every 5 years), with an increase in population exposure of 1.60-15.20% and 0.70-22.30% under 1.5°C and 2°C climate change. This has critical implications for adaptation to more extreme flood risk in Puerto Rico, as well as underlining the important implications of the 1.5°C Paris Agreement target for small islands – a finding that is likely to be applicable to other small islands affected by tropical cyclones.

 
Forecasting day-ahead 1-minute irradiance variability from NWP output 
Authors: Kreuwel Frank , van Heerwaarden Chiel
Published: March 2022

Forecasting day-ahead 1-minute irradiance variability from NWP output

 

Accurate forecasts of solar irradiance are required for the large scale integration of solar photovoltaic (PV) systems. Fluctuations of energy generation in the order of minutes can lead to issues on the electricity grid, therefore accurate forecasts of minute-to-minute irradiance variability are required. However, state of the art numerical weather predictions (NWP) deliver forecasts at a much coarser temporal resolution, e.g. hourly averages.

In this work we present a methodology to forecast a quantification of minute-to-minute irradiance variability as well as the probability distribution function (pdf), by applying statistical postprocessing and machine learning on hourly NWP ourput. In total, 10 target parameters related to the irradiance variability are forecasted. The algorithm is tested using the NWP HARMONIE-AROME (HA) mesoscale model as input, with 1-minute irradiance observations for 18 locations throughout the Netherlands used as ground truth.

Results show that the proposed algorithm is capable of forecasting the 1-minute irradiance PDF with reasonable resemblence to the observed PDF. Moreover, we show that inaccuracies of the postprocessed result are to a large extent due toerrors in the radiation forecast of the NWP used as input, reducing the average R2 score from 0.75 to .57 for the most relevant targets. The generalizability of the proposed algorithm is demonstrated by training the model on data of a single site and testing the performance on all 18 sites. Surprisingly, we find for 14 sites the model achieves higher accuracy than at the site it was trained on. Including data of all sites in the train set improves the accuracy on 3 of the 6 relevant target parameters while decreasing the accuracy on 1. Finally, we compare this work on post-processing to the next generation weather models based on high resolution Large Eddy Simulation (LES). A case study spanning four days is performed on four days well-captured by the NWP model and results are compared to results from the post-processing algorithm. While LES underestimates values of high irradiance due to lack of 3D radiative effects, it enables detailed analysis of the dynamics at high spatial and temporal resolution unreachable by statistical postprocessing.

The algorithm presented in this work is able to predict intra-hour irradiance variability based on day-ahead NWP output. Thereby moving forward significantly towards improving grid operation, planning, and resilience in relation to large-scale solar PV generation.