On Quasi-biennial oscillations in chromospheric macrospicules and their potential relation to global solar magnetic field

This study aims to provide further evidence for the potential influence of the global solar magnetic field on localised chromospheric jets, the macrospicules (MS). To find a connection between the long-term variation of properties of MS and other solar activity proxies, including e.g. the temporal variation of the frequency shift of solar global oscillations, sunspot area, etc., a database overarching seven years of observations was built up. This database contains 362 MS, based on observations at the 30.4 nm of the Atmospheric Imaging Assembly (AIA) on-board the Solar Dynamics Observatory (SDO). Three of the five investigated physical properties of MS show a clear long-term temporal variation after smoothing the raw data. Wavelet analysis of the temporal variation of maximum length, maximum area and average velocity is carried out. The results reveal a strong pattern of periodicities at around 2-year (also referred to as Quasi-Biennial Oscillations -- QBOs). Comparison to solar activity proxies, that also possess the properties of QBOs, provides some interesting features: the minima and maxima of QBOs of MS properties occur at around the same epoch as the minima and maxima of these activity proxies. For most of the time span investigated, the oscillations are out-of-phase. This out-of-phase behaviour was also corroborated by a cross-correlation analysis. These results suggest that the physical processes, that generate and drive the long-term evolution of the global solar activity proxies, may be coupled to the short-term local physical processes driving the macrospicules, and, therefore modulate the properties of local dynamics

An efficient and principled method for detecting communities in networks

A fundamental problem in the analysis of network data is the detection of network communities, groups of densely interconnected nodes, which may be overlapping or disjoint. Here we describe a method for finding overlapping communities based on a principled statistical approach using generative network models. We show how the method can be implemented using a fast, closed-form expectation-maximization algorithm that allows us to analyze networks of millions of nodes in reasonable running times. We test the method both on real-world networks and on synthetic benchmarks and find that it gives results competitive with previous methods. We also show that the same approach can be used to extract nonoverlapping community divisions via a relaxation method, and demonstrate that the algorithm is competitively fast and accurate for the nonoverlapping problem.Comment: 14 pages, 5 figures, 1 tabl

Non-homogeneous Behaviour of the Spatial Distribution of Macrospicules

In this paper the longitudinal and latitudinal spatial distribution of macrospicules is examined. We found a statistical relationship between the active longitude determined by sunspot groups and the longitudinal distribution of macrospicules. This distribution of macrospicules shows an inhomogeneity and non-axysimmetrical behaviour in the time interval from June 2010 until December 2012 covered by observations of the Solar Dynamic Observatory (SDO) satellite. The enhanced positions of the activity and its time variation has been calculated. The migration of the longitudinal distribution of macrospicules shows a similar behaviour as that of the sunspot groups

Water use and productivity of native and planted forests in NW Patagonia : ecohydrological and ecophysiological approaches

Existe preocupación por el posible uso excesivo de agua de las forestaciones con especies exóticas de rápido crecimiento en comparación con las especies nativas a las cuales reemplazan en la región NO de la Patagonia. Debido a ello, se han realizado estudios de productividad, consumo y eficiencia en el uso del agua tanto en plantaciones de especies exóticas como en sistemas vegetales naturales en zonas con distintos niveles de déficit hídrico. Esto se llevó a cabo mediante aproximaciones ecohidrológicas y ecofisiológicas. El objetivo del presente trabajo fue analizar y sintetizar el nivel de avance logrado en el conocimiento hasta la fecha. Tanto a nivel de árbol individual como de bosques con cobertura total de dosel arbóreo, las especies exóticas [Pinus ponderosa (pino ponderosa) y Pseudotsuga menziesii (pino oregón)] poseen un mayor consumo de agua que los individuos-sistemas nativos que crecen en sitios similares [pastizal, bosque de ciprés de la cordillera (Austrocedrus chilensis) y bosque mixto de ñire (Nothofagus antarctica) y radal (Lomatia hirsuta), y otras especies leñosas, respectivamente), aunque en todos los casos también se verificó un aumento en la eºciencia en el uso del agua. Los resultados sugieren que las diferencias en productividad y uso de agua se relacionan principalmente con una mayor resistencia hidráulica tanto de flujos en estado líquido (menor conductividad de la madera) como en estado gaseoso (mayor sensibilidad estomática a la demanda atmosférica) en las especies nativas. En el caso de las plantaciones de pino ponderosa, es posible disminuir el consumo de agua mediante el manejo del área foliar (podas y densidad de plantación). A su vez, en el bosque mixto nativo es posible manejar la cantidad y la eficiencia en el uso del agua mediante la extracción selectiva de ciertas especies y tamaños de individuos. Por otro lado, las mayores diferencias en el consumo de agua se observaron entre los pastizales y los bosques densos de pino ponderosa, los que a su vez se ubican en las zonas más secas del área forestable. Por otro lado, la interceptación de lluvias en la zona más árida fue mayor en los bosques nativos que en los implantados, lo cual hizo similar la evapotranspiración total de ambos, aunque es levemente superior en los bosques exóticos en la zona de mayor precipitación anual. Esto pone de manifiesto la importancia de considerar la ubicación, la densidad y el tamaño de los parches forestados en situaciones en las que los recursos hídricos excedentes de las precipitaciones quieran ser aprovechados aguas abajo en otras actividades. En este tipo de situaciones se recomiendan plantaciones con una baja densidad arbórea. Por el contrario, dado los excedentes de agua en la zona más húmeda (de aptitud para el pino oregón), el mayorconsumo de la especie exótica no redundaría en un impacto negativo sobre los recursos hídricos. Cabe destacar que dada la mayor eficiencia en el uso del agua de los sistemas exóticos, el costo en agua de la producción de madera de estos bosques es bastante menor al de los sistemas nativos.There is a concern about the potential excessive water used of forest plantations with fast growing exotic species compared to the native vegetation systems they replace in NW Patagonia. For this reason, several studies have being conducted focused on the productivity, water consumption and water use efficiency of the different systems, in areas with different precipitation levels. The studies were carried out from ecohydrological and ecophysiological approaches. The objective of this paper was to analyze and synthesize the available knowledge about these topics. Both at the individual tree level or at forest with complete cover systems, the exotic species (Pinus ponderosa and Pseudotsuga menziesii) have a higher water consumption than all native individual tree-vegetation systems they replace (grassland- Austrocedrus chilensis forests, and mixed forests with Nothofagus antarctica, Lomatia hirsuta, and other native woody species, respectively). However, in all cases, an increase in water use efficiency was observed in exotic species compared to native species. Our results suggest that differences in productivity and water use are mainly due to a higher resistance to water flow, both in liquid (lower wood conductivity) and vapor (higher stomatal sensitivity to vapor pressure deficit) phases in native species compared to exotic ones. At least in the case of ponderosa pine, water use of plantations may be decreased managing leaf area of the system by means of green pruning and thinning. Moreover, in the native mixed forest water use and water use efºciency are able to be managed through selective extraction of individuals of certain species and sizes. On the other hand, the higher differences in water use between native and exotic systems were observed in the most xeric areas, between native grasslands and high density ponderosa pine plantations. On the other hand, rain interception was higher in native forests than in forests plantations in the xeric area, resulting in similar whole evapotranspiration of both systems, whereas it was slightly higher in the forests plantations than in native systems in the humid area. This highlight the importance of considering the spatial distribution, density and size of plantation patches in those situations in which water surplus has to be used for other purposes. In these situations, it is recommended to install low density plantations. In contrast, due to the high water surplus in the more humid areas (with aptitude for Douglas-fir plantations), the higher water consumption of this exotic species compared to the native systems, would not lead to a negative impact on water resources. Finally, we highlight that, due to the high water use efficiency of exotic species, the wood production costs in terms of water are much lower using these species than native ones

Large-Scale Pretrained Model for Self-Supervised Music Audio Representation Learning

Self-supervised learning technique is an under-explored topic for music audio due to the challenge of designing an appropriate training paradigm. We hence propose MAP-MERT, a large-scale music audio pre-trained model for general music understanding. We achieve performance that is comparable to the state-of-the-art pre-trained model Jukebox using less than 2% of parameters

On the effectiveness of speech self-supervised learning for music

Self-supervised learning (SSL) has shown promising results in various speech and natural language processing applications. However, its efficacy in music information retrieval (MIR) still remains largely unexplored. While previous SSL models pre-trained on music recordings may have been mostly closed-sourced, recent speech models such as wav2vec2.0 have shown promise in music modelling. Nevertheless, research exploring the effectiveness of applying speech SSL models to music recordings has been limited. We explore the music adaption of SSL with two distinctive speech-related models, data2vec1.0 and Hubert, and refer to them as music2vec and musicHuBERT, respectively. We train 12 SSL models with 95M parameters under various pre-training configurations and systematically evaluate the MIR task performances with 13 different MIR tasks. Our findings suggest that training with music data can generally improve performance on MIR tasks, even when models are trained using paradigms designed for speech. However, we identify the limitations of such existing speech-oriented designs, especially in modelling polyphonic information. Based on the experimental results, empirical suggestions are also given for designing future musical SSL strategies and paradigms

MARBLE: Music Audio Representation Benchmark for Universal Evaluation

In the era of extensive intersection between art and Artificial Intelligence (AI), such as image generation and fiction co-creation, AI for music remains relatively nascent, particularly in music understanding. This is evident in the limited work on deep music representations, the scarcity of large-scale datasets, and the absence of a universal and community-driven benchmark. To address this issue, we introduce the Music Audio Representation Benchmark for universaL Evaluation, termed MARBLE. It aims to provide a benchmark for various Music Information Retrieval (MIR) tasks by defining a comprehensive taxonomy with four hierarchy levels, including acoustic, performance, score, and high-level description. We then establish a unified protocol based on 14 tasks on 8 public-available datasets, providing a fair and standard assessment of representations of all open-sourced pre-trained models developed on music recordings as baselines. Besides, MARBLE offers an easy-to-use, extendable, and reproducible suite for the community, with a clear statement on copyright issues on datasets. Results suggest recently proposed large-scale pre-trained musical language models perform the best in most tasks, with room for further improvement. The leaderboard and toolkit repository are published at this https URL to promote future music AI research

Systematic variations of macrospicule properties observed by SDO/AIA over half a decade

Macrospicules (MSs) are localized small-scale jet-like phenomena in the solar atmosphere, which have the potential to transport a considerable amount of momentum and energy from the lower solar atmospheric regions to the transition region and the low corona. A detailed statistical analysis of their temporal behavior and spatial properties is carried out in this work. Using state-of-the-art spatial and temporal resolution observations, yielded by the Atmospheric Imaging Assembly of Solar Dynamics Observatory, we constructed a database covering a 5.5 year long period, containing 301 macrospicules that occurred between 2010 June and 2015 December, detected at 30.4 nm wavelength. Here, we report the long-term variation of the height, length, average speed, and width of MS in coronal holes and Quiet Sun areas both in the northern and southern hemisphere of the Sun. This new database helps to refine our knowledge about the physical properties of MSs. Cross-correlation of these properties shows a relatively strong correlation, but not always a dominant one. However, a more detailed analysis indicates a wave-like signature in the behavior of MS properties in time. The periods of these long-term oscillatory behaviors are just under two years. Also, in terms of solar north/south hemispheres, a strong asymmetry was found in the spatial distribution of MS properties, which may be accounted for by the solar dynamo. This latter feature may then indicate a strong and rather intrinsic link between global internal and local atmospheric phenomena in the Sun

HiRISE - High-Resolution Imaging and Spectroscopy Explorer - ultrahigh resolution, interferometric and external occulting coronagraphic science

Recent solar physics missions have shown the definite role of waves and magnetic fields deep in the inner corona, at the chromosphere-corona interface, where dramatic and physically dominant changes occur. HiRISE (High Resolution Imaging and Spectroscopy Explorer), the ambitious new generation ultra-high resolution, interferometric, and coronagraphic, solar physics mission, proposed in response to the ESA Voyage 2050 Call, would address these issues and provide the best-ever and most complete solar observatory, capable of ultra-high spatial, spectral, and temporal resolution observations of the solar atmosphere, from the photosphere to the corona, and of new insights of the solar interior from the core to the photosphere. HiRISE, at the L1 Lagrangian point, would provide meter class FUV imaging and spectro-imaging, EUV and XUV imaging and spectroscopy, magnetic fields measurements, and ambitious and comprehensive coronagraphy by a remote external occulter (two satellites formation flying 375 m apart, with a coronagraph on a chaser satellite). This major and state-of-the-art payload would allow us to characterize temperatures, densities, and velocities in the solar upper chromosphere, transition zone, and inner corona with, in particular, 2D very high resolution multi-spectral imaging-spectroscopy, and, direct coronal magnetic field measurement, thus providing a unique set of tools to understand the structure and onset of coronal heating. HiRISE’s objectives are natural complements to the Parker Solar Probe and Solar Orbiter-type missions. We present the science case for HiRISE which will address: i) the fine structure of the chromosphere-corona interface by 2D spectroscopy in FUV at very high resolution; ii) coronal heating roots in the inner corona by ambitious externally-occulted coronagraphy; iii) resolved and global helioseismology thanks to continuity and stability of observing at the L1 Lagrange point; and iv) solar variability and space climate with, in addition, a global comprehensive view of UV variability