ALLIANCE: Spectral solver for kinetic plasma turbulence

The ALLIANCE code is developed to solve a new set of four-dimensional electromagnetic drift-kinetic equations in slab geometry [J. Plasma Phys. 88 905880117 (2022)]. The nonlinear equations are useful for the study of magnetized plasma systems at scales comparable to, or larger than the ion gyroradius. In particular, it is suited for the study the kinetic turbulent cascade in astrophysical plasma, while preserving finite Larmor radius effects at the fluid-kinetic transition. The equations solved are in spectral Fourier-Laguerre-Hermite form, a pseudo-spectral approach is used for the nonlinear terms, and the code is parallelised over multiple directions. After a presentation of the code, validation runs are shown, and benchmarks for serial and parallel computations are presented

The anisotropic redistribution of free energy for gyrokinetic plasma turbulence in a Z-pinch

For a Z-pinch geometry, we report on the nonlinear redistribution of free energy across scales perpendicular to the magnetic guide field, for a turbulent plasma described in the framework of gyrokinetics. The analysis is performed using a local flux-surface approximation, in a regime dominated by electrostatic fluctuations driven by the entropy mode, with both ion and electron species being treated kinetically. To explore the anisotropic nature of the free energy redistribution caused by the emergence of zonal flows, we use a polar coordinate representation for the field-perpendicular directions and define an angular density for the scale flux. Positive values for the classically defined (angle integrated) scale flux, which denote a direct energy cascade, are shown to be also composed of negative angular sections, a fact that impacts our understanding of the backscatter of energy and the way in which it enters the modeling of sub-grid scales for turbulence. A definition for the flux of free energy across each perpendicular direction is introduced as well, which shows that the redistribution of energy in the presence of zonal flows is highly anisotropic

A nonlinear approach to transition in subcritical plasmas with sheared flow

In many plasma systems, introducing a small background shear flow is enough to stabilize the system linearly. The nonlinear dynamics are much less sensitive to sheared flows than the average linear growthrates, and very small amplitude perturbations can lead to sustained turbulence. We explore the general problem of characterizing how and when the transition from near-laminar states to sustained turbulence occurs; a model of the interchange instability being used as a concrete example. These questions are fundamentally nonlinear, and the answers must go beyond the linear transient amplification of small perturbations. Two methods that account for nonlinear interactions are therefore explored here. The first method explored is edge tracking, which identifies the boundary between the basins of attraction of the laminar and turbulent states. Here, the edge is found to be structured around an exact, localized, traveling wave solution; a solution that is qualitatively similar to avalanche-like bursts seen in the turbulent regime. The second method is an application of nonlinear, non-modal stability theory which allows us to identify the smallest disturbances which can trigger turbulence (the minimal seed for the problem) and hence to quantify how stable the laminar regime is. The results obtained from these fully nonlinear methods provides confidence in the derivation of a semi-analytic approximation for the minimal seed

Applications of large eddy simulation methods to gyrokinetic turbulence

The Large Eddy Simulation (LES) approach - solving numerically the large scales of a turbulent system and accounting for the small-scale influence through a model - is applied to nonlinear gyrokinetic systems that are driven by a number of different microinstabilities. Comparisons between modeled, lower resolution, and higher resolution simulations are performed for an experimental measurable quantity, the electron density fluctuation spectrum. Moreover, the validation and applicability of LES is demonstrated through a series of diagnostics based on the free energetics of the system.Comment: 14 pages, 9 figure

Gyrokinetic turbulence:between idealized estimates and a detailed analysis of nonlinear energy transfers

Using large resolution numerical simulations of GK turbulence, spanning an interval ranging from the end of the fluid scales to the electron gyroradius, we study the energy transfers in the perpendicular direction for a proton-electron plasma in a slab magnetic geometry. In addition, to aid our understanding of the nonlinear cascade, we use an idealized test representation for the energy transfers between two scales, mimicking the dynamics of turbulence in an infinite inertial range. For GK turbulence, a detailed analysis of nonlinear energy transfers that account for the separation of energy exchanging scales is performed. We show that locality functions associated with the energy cascade across dyadic (i.e. multiple of two) separated scales achieve an asymptotic state, recovering clear values for the locality exponents. We relate these exponents to the energy exchange between two scales, diagnostics that are less computationally intensive than the locality functions. It is the first time asymptotic locality is shown to exist for GK turbulence and the contributions made by highly non-local interactions, previously reported in the literature, are explained as very local transfers of energy that occur between wavenumbers within the same dyadic signal. The results presented here and their implications are discussed from the perspective of previous findings reported in the literature and the idea of universality of GK turbulence

Cosmic-ray pitch-angle scattering in imbalanced mhd turbulence simulations

Pitch-angle scattering rates for cosmic-ray particles in magnetohydrodynamic (MHD) simulations with imbalanced turbulence are calculated for fully evolving electromagnetic turbulence. We compare with theoretical predictions derived from the quasilinear theory of cosmic-ray diffusion for an idealized slab spectrum and demonstrate how cross helicity affects the shape of the pitch-angle diffusion coefficient. Additional simulations in evolving magnetic fields or static field configurations provide evidence that the scattering anisotropy in imbalanced turbulence is not primarily due to coherence with propagating Alfven waves, but an effect of the spatial structure of electric fields in cross-helical MHD turbulence.Comment: 13 pages, 15 figures. Accepted by Ap

Unpublished Mediterranean and Black Sea records of marine alien, cryptogenic, and neonative species

To enrich spatio-temporal information on the distribution of alien, cryptogenic, and neonative species in the Mediterranean and the Black Sea, a collective effort by 173 marine scientists was made to provide unpublished records and make them open access to the scientific community. Through this effort, we collected and harmonized a dataset of 12,649 records. It includes 247 taxa, of which 217 are Animalia, 25 Plantae and 5 Chromista, from 23 countries surrounding the Mediterranean and the Black Sea. Chordata was the most abundant taxonomic group, followed by Arthropoda, Mollusca, and Annelida. In terms of species records, Siganus luridus, Siganus rivulatus, Saurida lessepsianus, Pterois miles, Upeneus moluccensis, Charybdis (Archias) longicollis, and Caulerpa cylindracea were the most numerous. The temporal distribution of the records ranges from 1973 to 2022, with 44% of the records in 2020–2021. Lethrinus borbonicus is reported for the first time in the Mediterranean Sea, while Pomatoschistus quagga, Caulerpa cylindracea, Grateloupia turuturu, and Misophria pallida are first records for the Black Sea; Kapraunia schneideri is recorded for the second time in the Mediterranean and for the first time in Israel; Prionospio depauperata and Pseudonereis anomala are reported for the first time from the Sea of Marmara. Many first country records are also included, namely: Amathia verticillata (Montenegro), Ampithoe valida (Italy), Antithamnion amphigeneum (Greece), Clavelina oblonga (Tunisia and Slovenia), Dendostrea cf. folium (Syria), Epinephelus fasciatus (Tunisia), Ganonema farinosum (Montenegro), Macrorhynchia philippina (Tunisia), Marenzelleria neglecta (Romania), Paratapes textilis (Tunisia), and Botrylloides diegensis (Tunisia)

Unpublished Mediterranean and Black Sea records of marine alien, cryptogenic, and neonative species

To enrich spatio-temporal information on the distribution of alien, cryptogenic, and neonative species in the Mediterranean and the Black Sea, a collective effort by 173 marine scientists was made to provide unpublished records and make them open access to the scientific community. Through this effort, we collected and harmonized a dataset of 12,649 records. It includes 247 taxa, of which 217 are Animalia, 25 Plantae and 5 Chromista, from 23 countries surrounding the Mediterranean and the Black Sea. Chordata was the most abundant taxonomic group, followed by Arthropoda, Mollusca, and Annelida. In terms of species records, Siganus luridus, Siganus rivulatus, Saurida lessepsianus, Pterois miles, Upeneus moluccensis, Charybdis (Archias) longicollis, and Caulerpa cylindracea were the most numerous. The temporal distribution of the records ranges from 1973 to 2022, with 44% of the records in 2020–2021. Lethrinus borbonicus is reported for the first time in the Mediterranean Sea, while Pomatoschistus quagga, Caulerpa cylindracea, Grateloupia turuturu, and Misophria pallida are first records for the Black Sea; Kapraunia schneideri is recorded for the second time in the Mediterranean and for the first time in Israel; Prionospio depauperata and Pseudonereis anomala are reported for the first time from the Sea of Marmara. Many first country records are also included, namely: Amathia verticillata (Montenegro), Ampithoe valida (Italy), Antithamnion amphigeneum (Greece), Clavelina oblonga (Tunisia and Slovenia), Dendostrea cf. folium (Syria), Epinephelus fasciatus (Tunisia), Ganonema farinosum (Montenegro), Macrorhynchia philippina (Tunisia), Marenzelleria neglecta (Romania), Paratapes textilis (Tunisia), and Botrylloides diegensis (Tunisia).Stelios Katsanevakis, Michail Ragkousis, Maria Sini, Markos Digenis and Vasilis Gerovasileiou were supported by the Hellenic Foundation for Research and Innovation (HFRI) under the “First Call for HFRI Research Projects to support Faculty members and Researchers and the procurement of high-cost research equipment grant” (Project ALAS – “ALiens in the Aegean – a Sea under siege” (Katsanevakis et al. 2020b); Project Number: HFRI-FM17-1597). Konstantinos Tsirintanis was co-financed by Greece and the European Union (European Social Fund-ESF) through the Operational Programme “Human Resources Development, Education and Lifelong Learning”, 2014-2020, in the context of the Act “Enhancing Human Resources Research Potential by undertaking a Doctoral Research” Sub-action 2: IKY Scholarship Programme for PhD candidates in the Greek Universities. Maria Zotou was supported by the project “Coastal Environment Observatory and Risk Management in Island Regions AEGIS+” (MIS 5047038), implemented within the Operational Programme “Competitiveness, Entrepreneurship and Innovation” (NSRF 2014-2020), co financed by the Hellenic Government (Ministry of Development and Investments) and the European Union (European Regional Development Fund, Cohesion Fund). Razy Hoffman was supported by Yad-Hanadiv Foundation, through the Israel Society of Ecology and Environmental Sciences and Israel Nature and Parks Authority, an integrated program for establishing biological baselines and monitoring protocols for marine reserves in the Israeli Mediterranean Sea (Grant #10669). Tatiana Begun, Adrian Teaca and Mihaela Muresan were supported by the European Union’s Horizon 2020 BRIDGE-BS project under grant agreement no. 101000240. Fiona Tomas was supported by the project “Invasion of the tropical alga Halimeda incrassata in the Balearic Islands: ecology and invasion dynamics (AAEE119/2017)”, funded by the Vicepresidencia y Consejería de Innovación, Investigación y Turismo del Govern de les Illes Balears, with support from the European Union and FEDER funds, and the project “Una nueva alga invasora en el Mediterráneo: invasibilidad, detección y erradicación del alga tropical Halimeda incrassata (INVHALI)”, funded by the Fundación Biodiversidad, del Ministerio para la Transición Ecológica y el Reto Demográfico. Simonetta Fraschetti, Laura Tamburello, Antonia Chiarore were supported by the project PO FEAMP 2014-2020 - DRD n. 35/2019, “Innovazione, sviluppo e sostenibilità nel settore della pesca e dell'acquacoltura per la Regione Campania” (ISSPA 2.51) and the EU EASME - EMFF (Sustainable Blue Econ-omy) Project AFRIMED (http://afrimed-project.eu/, grant agreement N. 789059). Carlos Jimenez, Louis Hadjioannou, Vasilis Resaikos, Valentina Fossati, Magdalene Papatheodoulou, and Antonis Petrou were supported by MedPan Small Projects, Mava, and LIFE-IP. Louis Hadjioannou, Manos L. Moraitis and Neophytos Agrotis received funding from the European Union’s Horizon 2020 research and innovation program within the framework of the CMMI/MaRITeC-X project under grant agreement No. 857586. Ernesto Azzurro was supported by the project USEIt - Utilizzo di Sinergie operative per la gestione integrata specie aliene Invasive in Italia, funded by the research programme @CNR. Antonietta Rosso and Francesco Sciuto were supported by the University of Catania through “PiaCeRi-Piano Incentivi per la Ricerca di Ateneo 2020–22 linea di intervento 2.” This is the Catania Paleoecological Research Group contribution n. 484. Diego K. Kersting was supported by the Beatriu de Pinós programme funded by the Secretary of Universities and Research (Government of Catalonia) and the Horizon 2020 programme of research and innovation of the European Union under the Marie Sklodowska-Curie grant agreement No 801370. Francesco Tiralongo was supported by the AlienFish project of Ente Fauna Marina Mediterranea (Scientific Organization for Research and Conservation of Marine Biodiversity, 96012 Avola, Italy), a citizen science project for monitoring and studying rare and non-indigenous fish in Italian waters. Adriana Vella, was supported by funds through the BioCon_Innovate Research Excellence Grant from the University of Malta awarded to her. Noel Vella was supported by REACH HIGH Scholars Programme-Post Doctoral Grant for the FINS project. Some of the records provided by Victor Surugiu were obtained during surveys carried out within the framework of the project “Adequate management of invasive species in Romania, in accordance with EU Regulation 1143/2014 on the prevention and management of the introduction and spread of invasive alien species”, SMIS 2014+ 120008, coordinated by the Romanian Ministry of Environment, Water and Forests in partnership with the University of Bucharest (2018–2022). Alan Deidun and Alessio Marrone were supported by the “Spot The Alien” citizen science campaign for the monitoring of the Alien species in the Maltese archipelago and by the Interreg Italia-Malta Harmony project. The authors from the National Institute of Biology (Slovenia) acknowledge the financial support of the Slovenian Research Agency (Research Core Funding No. P1-0237) and of the Ministry of Agriculture, Forestry and Food (project “Survey of the species richness and abundance of alien species in the Slovenian Sea”). Emanuele Mancini and Fabio Collepardo Coccia were supported by the project PO-FEAMP 2014-2020 “BIOBLITZ: research, knowledge and participation for the sustainable management of marine resources (BioBlitz Blu 2020)” coordinated by CURSA for MIPAAF, the Italian Ministry of Agricultural, Food and Forestry Policies, Measure 1.40 - Protection and restoration of biodiversity and marine ecosystems and compensation schemes in the context of sustainable fishing activities. Daniele Grech was supported by the PO-FEAMP 2014-2020 project ECOGESTOCK “Approccio ECOsistemico per la tutela e la GEStione delle risorse biologiche e STOCK ittici nelle acque interne”, the citizen science project Progetto Fucales: chi le ha viste? and the Paralenz Every dive counts sponsor. Jamila Rizgalla was supported by the project Snowball for the monitoring of alien species in Libyan waters له اهتفش له اهتدطصا ؟) have you seen it have you fished it?). Gerasimos Kondylatos and Dimitrios Mavrouleas were supported by the project “EXPLIAS” (MIS (ΟΠΣ): 5049912), design and piloting methods of commercial exploitation of invasive alien species with a view to contributing to their population control, coordinated by the National Technical University of Athens with the collaboration of the Hellenic Centre for Marine Research and the University of the Aegean and co-founded by Greece and the European Union. G. Kondylatos and Savvas Nikolidakis were supported by the project “SAMOS” (ID CODE: 32.2072004/001), a study for a submarine productive park in Marathokampos of Samos. Paraskevi K. Karachle, Aikaterini Dogrammatzi, Giorgos A. Apostolopoulos, Kassiani Konida and Melina Nalmpanti were supported by the project “4ALIEN: Biology and the potential economic exploitation of four alien species in the Hellenic Seas”, funded by NRSF 2017-2020 (MIS (ΟΠΣ): 5049511). Fabio Crocetta and Riccardo Virgili were partially funded by the project PO FEAMP Campania 2014–2020, DRD n. 35 of 15th March 2018, Innovazione, sviluppo e sostenibilità nel settore della pesca e dell’acquacoltura per la regione Campania, Misura 2.51, WP5, Task 5.5 Presenza e distribuzione di specie non indigene del macrozoobenthos e del necton in Campania. Michel Bariche was partially funded by the University Research Board of the American University of Beirut (DDF 103951/2592). Constantinos G. Georgiadis, Dimitra Lida Rammou, Paschalis Papadamakis and Sotiris Orfanidis were supported by the MSFD monitoring program. Sonia Smeraldo was supported by the MPA-Engage project, led by the Institute of Marine Sciences of the Spanish National Research Council and funded by the Interreg MED program. Evgeniia Karpova acknowledge that the publication of this article was in part carried out within the framework of the state assignment of the FRC IBSS “Patterns of Formation and Anthropogenic Transformation of Biodiversity and Bioresources of the Azov– Black Sea Basin and Other Regions of the World Ocean” (No. 121030100028-0). Elena Slynko’s work was carried out within the framework of a State Assignment no. 121051100109-1 of IBIW RAS. Manuela Falautano and Luca Castriota were supported by ISPRA citizen science campaigns for the monitoring of alien species through the dedicated institutional project ([email protected]). María Altamirano was supported by the project RUGULOPTERYX funded by Fundación Biodiversidad-Ministerio para la Transición Ecológica y el reto Demográfico (Spain) and the project UMA20-FEDERJA-006 with support from the European Union and FEDER funds and Junta de Andalucía. Records provided by L. Mangialajo were collected in the framework of projects funded by the Pew Charitable Trust, by the European Commission (AFRIMED, http://afrimed-project.eu/, grant agreement N. 789059) and by the Académie 3 de l’Université Côte d’Azur (projet CONVOST).Peer reviewe

Unpublished Mediterranean and Black Sea records of marine alien, cryptogenic, and neonative species

To enrich spatio-temporal information on the distribution of alien, cryptogenic, and neonative species in the Mediterranean and the Black Sea, a collective effort by 173 marine scientists was made to provide unpublished records and make them open access to the scientific community. Through this effort, we collected and harmonized a dataset of 12,649 records. It includes 247 taxa, of which 217 are Animalia, 25 Plantae and 5 Chromista, from 23 countries surrounding the Mediterranean and the Black Sea. Chordata was the most abundant taxonomic group, followed by Arthropoda, Mollusca, and Annelida. In terms of species records, Siganus luridus, Siganus rivulatus, Saurida lessepsianus, Pterois miles, Upeneus moluccensis, Charybdis (Archias) longicollis, and Caulerpa cylindracea were the most numerous. The temporal distribution of the records ranges from 1973 to 2022, with 44% of the records in 2020–2021. Lethrinus borbonicus is reported for the first time in the Mediterranean Sea, while Pomatoschistus quagga, Caulerpa cylindracea, Grateloupia turuturu, and Misophria pallida are first records for the Black Sea; Kapraunia schneideri is recorded for the second time in the Mediterranean and for the first time in Israel; Prionospio depauperata and Pseudonereis anomala are reported for the first time from the Sea of Marmara. Many first country records are also included, namely: Amathia verticillata (Montenegro), Ampithoe valida (Italy), Antithamnion amphigeneum (Greece), Clavelina oblonga (Tunisia and Slovenia), Dendostrea cf. folium (Syria), Epinephelus fasciatus (Tunisia), Ganonema farinosum (Montenegro), Macrorhynchia philippina (Tunisia), Marenzelleria neglecta (Romania), Paratapes textilis (Tunisia), and Botrylloides diegensis (Tunisia).peer-reviewe