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Haydn’s Seasons suffered in the critical reception of its time owing to the sublime’s proximity to the humorous or quotidian, two of the sublime’s ‘off-switches’, especially after the unproblematic sublimity of The Creation. Van Swieten’s cataloguing talents as imperial librarian are on view as librettist of both oratorios, but only The Seasons reflected his thematic choices. His poetry allowed Haydn to showcase the effects of nature’s excesses in the ‘extreme’ seasons, making the sublime ‘start’ and ‘stop’ not only in the choruses invoking God, the eruption of the storm and the sounding of the Last Judgment, but also in the quieter solos in Summer and Winter, both cavatinas, when the sun’s overwhelming presence or absence makes animate nature gasp for air. The ‘quotidian sublime’ of the sunset tapestry that closes Summer brings healing after terror. Haydn’s two Mozart quotations in The Seasons make powerful references to the life cycle as the work’s dominant metaphor, but hitherto unremarked is Haydn’s spotlight on the rising-sixth interval in Spring and Winter as Mozart uses it in The Magic Flute for moments of recognition. In thus suggesting sublime Mozart’s spirit framing the whole, Haydn’s work offers a key to Beethoven’s Cavatina in Op. 130.
On the centenary of the International Union of Geodesy and Geophysics, this book reviews the state-of-the-art research in geomagnetism, aeronomy and space weather. Written by eminent researchers from these fields, it summarises the advances in research over the past 100 years, and looks ahead to current and emerging studies on Earth's magnetic field. It provides a comprehensive overview of the generation of Earth's magnetic field, its history and its response to external forces. Starting at the centre of the Earth, the reader is taken on a journey from the interior core and mantle, through the upper atmosphere and magnetosphere, before reaching the Sun's atmosphere and corona. The applications of this research are also discussed, particularly the societal impact of solar activity on critical infrastructures in our increasingly technologically dependant society. This book provides a valuable resource and reference to academic researchers and students in geomagnetism and aeronomy.
The search for life in the Universe is a fundamental problem of astrobiology and modern science. The current progress in the detection of terrestrial-type exoplanets has opened a new avenue in the characterization of exoplanetary atmospheres and in the search for biosignatures of life with the upcoming ground-based and space missions. To specify the conditions favourable for the origin, development and sustainment of life as we know it in other worlds, we need to understand the nature of global (astrospheric), and local (atmospheric and surface) environments of exoplanets in the habitable zones (HZs) around G-K-M dwarf stars including our young Sun. Global environment is formed by propagated disturbances from the planet-hosting stars in the form of stellar flares, coronal mass ejections, energetic particles and winds collectively known as astrospheric space weather. Its characterization will help in understanding how an exoplanetary ecosystem interacts with its host star, as well as in the specification of the physical, chemical and biochemical conditions that can create favourable and/or detrimental conditions for planetary climate and habitability along with evolution of planetary internal dynamics over geological timescales. A key linkage of (astro)physical, chemical and geological processes can only be understood in the framework of interdisciplinary studies with the incorporation of progress in heliophysics, astrophysics, planetary and Earth sciences. The assessment of the impacts of host stars on the climate and habitability of terrestrial (exo)planets will significantly expand the current definition of the HZ to the biogenic zone and provide new observational strategies for searching for signatures of life. The major goal of this paper is to describe and discuss the current status and recent progress in this interdisciplinary field in light of presentations and discussions during the NASA Nexus for Exoplanetary System Science funded workshop ‘Exoplanetary Space Weather, Climate and Habitability’ and to provide a new roadmap for the future development of the emerging field of exoplanetary science and astrobiology.
This chapter sets the scene for the discussion, presenting the MHD equations and their basic properties before turning to a discussion of the basic ideas of wave propagation. A variety of plasmas are also briefly reviewed with most attention devoted to the solar atmosphere and its observed features. Coronal loops and sunspots are given some attention.
The process of linearization of equations is described. Also, the two fundamental speeds that arise, the sound speed and Alfven speed, are defined and evaluated for illustrative purposes. The concepts of phase speed and group velocity are introduced.
Based on our modern 4D-var data assimilation pipeline Solar Predict we present in this short proceeding paper our prediction for the next solar cycle 25. As requested by the Solar Cycle 25 panel call issued on January 2019 by NOAA/SWPC and NASA, we predict the timing of next minimum and maximum as well as their amplitude. Our results are the following: the minimum should have occured within the first semester of year 2019. The maximum should occur in year 2024.4 ± 6 months, with a value of the sunspot number equal to 92±10. This is in agreement with the NOAA/NASA consensus published in April 2019. Note that our prediction errors are based on 1-σ measure and do not consider all the systematics, so they are likely underestimated. We will update our prediction and error analysis regularly as more data becomes available and we improve our prediction pipeline.
The stars move from east to west across the sky each night. The ancient Greeks realized that the apparent movement of the stars would make sense if the stars were stuck on the inner surface of a giant celestial sphere that rotated around the Earth once every sidereal day. The Sun also moves from east to west across the sky, but not quite in the same way as the stars. The Sun’s motion can be tracked using shadows, and it appears to move eastward relative to the sphere of the stars along a path that is tilted relative to the celestial equator. The Sun completes its motion around the celestial sphere in one year, traveling through the constellations of the zodiac along a path called the ecliptic. As an observer moves around on Earth the apparent motions of the stars and Sun change in a way that shows the Earth to be spherical. The stars also display a very slow motion known as the precession of the equinoxes with a period of about 26,000 years.
To study plasma 25-hydroxyvitamin D (25(OH)D) status of children in Kerala, southern India, and its relationship with sociodemographic variables.
Cross-sectional observational study.
Tertiary government hospital.
Children (n 296) with trivial acute illness were enrolled. Sun exposure and Ca and vitamin D intakes (7 d dietary recall) were documented. Serum Ca, P, alkaline phosphatase, plasma 25(OH)D and parathyroid hormone (PTH) were measured.
Prevalence of vitamin D deficiency (plasma 25(OH)D <30 nmol/l) was 11·1% (median, interquartile range (IQR): 52·6, 38·4–65·6 nmol/l). Children who ate fish daily had significantly higher plasma 25(OH)D than those who did not (median, IQR: 52·5, 40·8–68·9 v. 49·1, 36·2–60·7 nmol/l; P = 0·02). Those investigated in the months of March–May showed highest 25(OH)D v. those enrolled during other times (median, IQR: 58·7, 45·6–81·4 v. 45·5, 35·6–57·4 nmol/l; P <0·001). Plasma 25(OH)D correlated positively with serum P (r = 0·24, P <0·001) and Ca intake (r = 0·16, P 0·03), negatively with age (r = −0·13, P 0·03) and PTH (r = −0·22, P <0·001.). On linear regression, summer season (March–May), lower age, daily fish intake and higher Ca intake were independently associated with plasma 25(OH)D.
Prevalence of vitamin D deficiency is low in Kerala. The natural fish diet of coastal Kerala and the latitude may be protective. Public health policy in India should take account of this geographical diversity.
The Compact Lightweight Absolute Radiometer (CLARA) is orbiting Earth on-board the Norwegian NorSat-1 micro-satellite since 14th of July 2017. The first light total solar irradiance (TSI) measurement result of CLARA is 1360.18 W m−2 for the so far single reliable Channel B. Channel A and C measured significantly lower (higher) TSI values and were found being sensitive to satellite pointing instabilities. These channels most likely suffer from electrical interference between satellite components and CLARA, an effect that is currently under investigation. Problems with the satellite attitude control currently inhibit stable pointing of CLARA to the Sun.
Our understanding of stellar dynamos has largely been driven by the phenomena we have observed of our own Sun. Yet, as we amass longer-term datasets for an increasing number of stars, it is clear that there is a wide variety of stellar behavior. Here we briefly review observed trends that place key constraints on the fundamental dynamo operation of solar-type stars to fully convective M dwarfs, including: starspot and sunspot patterns, various magnetism-rotation correlations, and mean field flows such as differential rotation and meridional circulation. We also comment on the current insight that simulations of dynamo action and flux emergence lend to our working knowledge of stellar dynamo theory. While the growing landscape of both observations and simulations of stellar magnetic activity work in tandem to decipher dynamo action, there are still many puzzles that we have yet to fully understand.
We are performed the digitization of the prominences from the full disk observations of the Sun in the CaIIK line Kodaikanal Observatory for the period 1904-1954. These data were supplemented by digitization of prominences data on Wolfer atlases for the period 1887-1900 and observations of Kislovodsk Observatory in the period 1957-2017. Particular attention was paid to study of the polar crown prominences drift time. The time interval of the prominence drift is ambiguous from the sunspot cycle amplitude.
An onboard automated coronal mass ejections (CMEs) detection algorithm has been developed for Visible Emission Line Coronagraph (VELC) onboard ADITYA-L1. The aim of this algorithm is to reduce the load on telemetry by sending the high spatial (~ 2.51 arcsec pixel−1) and temporal (1 s) resolution images of corona from 1.05 R⊙ to 3 R⊙, containing CMEs and rejecting others. It is based on intensity thresholding followed by an area thresholding in successive running difference images which are re-binned to lower resolution to improve signal to noise. Here we present the results of application of the algorithm on synthetic corona images generated for the VELC field of view (FOV).
Digitization of solar activity data over a period of more than 100 years has been performed. The database presents the characteristics of sunspots, sunspot umbras, filaments, plages in CaIIK line and prominences. The series of vector boundaries and photometric properties of the selected objects are created.
The characteristics of individual types of solar activity were determined. An interactive atlas of solar activity has been created, on which daily maps of solar activity, characteristics of individual elements and summary indices of solar activity are presented. The indices of solar activity were reconstructed and the analysis was carried out.
Magnetic reconnections (MRs) for various magnetic field line (MFL) topologies are believed to be the initiators of solar eruptive events like flares and coronal mass ejections (CMEs). Consequently, important is a thorough understanding and quantification of the MFL topology and their evolution which leads to MRs. Contemporary standard is to extrapolate the coronal MFLs using equilibrium models where the Lorentz force on the coronal plasma is zero everywhere. In tandem, a non-force-free-field (NFFF) extrapolation scheme has evolved and allows for a Lorentz force which is non-zero only at the photosphere but asymptotically vanishes with height. The paper reports magnetohydrodynamic (MHD)- simulations initiated by NFFF extrapolation of the coronal MFLs for a flare producing active region NOAA 11158. Interestingly, quasi-separatrix layers (QSLs) which facilitate MRs are detected in the extrapolated MFLs and, here the paper makes an attempt to asses the role of QSLs in the flare onsets.
Reconstruction of regions with an open configuration of magnetic force lines was carried out according to synoptic Hα maps over a period of more than 100 years. It is shown that the maximum area of open structures in the cycle of solar activity is reached in the descending phase, 1÷2 years before the onset of the minimum. The total area of open structures in the current cycle n has a high correlation (r ~ 0.8) with the amplitude of the next activity cycle n + 1. There is also a secular envelope with a maximum in the middle of the 20th century.
Recent helioseismic estimates of the deep solar meridional flow have been contradictory. Using two years worth of GONG data, I show here that the detection of the meridional flow is ambiguous below about 0.85 solar radii.
Visible Emission Line Coronagraph (VELC) on board ADITYA-L1 is an internally occulted coronagraph with mirror as its primary objective element. It has a field of view (FOV) starting from 1.05 R⊙ – 3 R⊙. It will observe the corona in continuum centered at 5000 Å and will perform spectroscopic observations of inner corona in two visible (5303 Å and 7892 Å) and one infrared (10747 Å) wavelengths. VELC will be capable of observing the corona with high spatial and temporal resolutions. We present an overview of the inner coronagraph (VELC) design and introduce the concept of an on-board automated coronal mass ejections (CMEs) detection logic proposed for this payload.
Preliminary results of distinguishing solar filaments on daily observation data at the Hα spectral line of the Kodaikanal Solar Observatory (1912-2002) are presented.
To distinguish the boundaries of solar filaments, methods have been developed, based on automatic procedures for distinguishing low-contrast objects on the solar disk as well as on editing the boundaries of selected structures in semi-automatic mode. An analysis of solar filaments’ characteristics has been performed. We are considered variation of the average tilt-angle and the radius of curvature of the filaments in 15-23 cycles of activity.
The space weather forecast can be conditionally divided into three components: 1) The forecast of recurrent slowly varying events which are associated with the topology of a large-scale magnetic field; 2) Evaluation of fluxes of ultraviolet and extreme radiation; 3) Detecting and determining the parameters of eruptions and CME. All three components can be observed and evaluated by ground-based telescopes. In this article we describe the telescopes of the space weather service in Kislovodsk Mountain Astronomical Station. Telescope-magnetograph STOP for the forecast of recurrent events and patrol telescopes-spectrographs for detecting CME and estimating hard radiation fluxes.
The Scandinavian landscape is littered with postglacial outcrops, many of which carry engraved motifs. Although drawings of ships are most often discussed, this paper focuses on representations of feet. In Northern Europe ship motifs are often associated with cosmologies based on the movement of the sun. This paper investigates whether drawings of feet could have been associated with the same worldview. A number of interpretations are offered of the images at two sites in different parts of Sweden: Järrestad 13:1 and Boglösa 138:1.